[Federal Register Volume 76, Number 179 (Thursday, September 15, 2011)]
[Rules and Regulations]
[Pages 57105-57513]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-20740]



[[Page 57105]]

Vol. 76

Thursday,

No. 179

September 15, 2011

Part II





Environmental Protection Agency





-----------------------------------------------------------------------





40 CFR Parts 85, 86, 600, et al.





Department of Transportation





-----------------------------------------------------------------------





National Highway Traffic Safety Administration





-----------------------------------------------------------------------

49 CFR Parts 523, 534, and 535





Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for 
Medium- and Heavy-Duty Engines and Vehicles; Final Rule

Federal Register / Vol. 76, No. 179 / Thursday, September 15, 2011 / 
Rules and Regulations

[[Page 57106]]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 85, 86, 600, 1033, 1036, 1037, 1039, 1065, 1066, and 
1068

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 523, 534, and 535

[EPA-HQ-OAR-2010-0162; NHTSA-2010-0079; FRL-9455-1]
RIN 2060-AP61; 2127-AK74


Greenhouse Gas Emissions Standards and Fuel Efficiency Standards 
for Medium- and Heavy-Duty Engines and Vehicles

AGENCY: Environmental Protection Agency (EPA) and National Highway 
Traffic Safety Administration (NHTSA), DOT.

ACTION: Final Rules.

-----------------------------------------------------------------------

SUMMARY: EPA and NHTSA, on behalf of the Department of Transportation, 
are each finalizing rules to establish a comprehensive Heavy-Duty 
National Program that will reduce greenhouse gas emissions and fuel 
consumption for on-road heavy-duty vehicles, responding to the 
President's directive on May 21, 2010, to take coordinated steps to 
produce a new generation of clean vehicles. NHTSA's final fuel 
consumption standards and EPA's final carbon dioxide (CO2) 
emissions standards are tailored to each of three regulatory categories 
of heavy-duty vehicles: Combination Tractors; Heavy-duty Pickup Trucks 
and Vans; and Vocational Vehicles. The rules include separate standards 
for the engines that power combination tractors and vocational 
vehicles. Certain rules are exclusive to the EPA program. These include 
EPA's final hydrofluorocarbon standards to control leakage from air 
conditioning systems in combination tractors, and pickup trucks and 
vans. These also include EPA's final nitrous oxide (N2O) and 
methane (CH4) emissions standards that apply to all heavy-
duty engines, pickup trucks and vans.
    EPA's final greenhouse gas emission standards under the Clean Air 
Act will begin with model year 2014. NHTSA's final fuel consumption 
standards under the Energy Independence and Security Act of 2007 will 
be voluntary in model years 2014 and 2015, becoming mandatory with 
model year 2016 for most regulatory categories. Commercial trailers are 
not regulated in this phase of the Heavy-Duty National Program.
    The agencies estimate that the combined standards will reduce 
CO2 emissions by approximately 270 million metric tons and 
save 530 million barrels of oil over the life of vehicles sold during 
the 2014 through 2018 model years, providing over $7 billion in net 
societal benefits, and $49 billion in net societal benefits when 
private fuel savings are considered.
    EPA is also finalizing provisions allowing light-duty vehicle 
manufacturers to use CO2 credits to meet the light-duty 
vehicle N2O and CH4 standards, technical 
amendments to the fuel economy provisions for light-duty vehicles, and 
a technical amendment to the criteria pollutant emissions requirements 
for certain switch locomotives.

DATES: These final rules are effective on November 14, 2011. The 
incorporation by reference of certain publications listed in this 
regulation is approved by the Director of the Federal Register as of 
November 14, 2011.

ADDRESSES: EPA and NHTSA have established dockets for this action under 
Docket ID No. EPA-HQ-OAR-2010-0162 and NHTSA-2010-0079, respectively. 
All documents in the docket are listed on the http://www.regulations.gov Web site. Although listed in the index, some 
information is not publicly available, e.g., confidential business 
information or other information whose disclosure is restricted by 
statute. Certain other material, such as copyrighted material, is not 
placed on the Internet and will be publicly available only in hard copy 
form. Publicly available docket materials are available either 
electronically through http://www.regulations.gov or in hard copy at 
the following locations: EPA: EPA Docket Center, EPA/DC, EPA West 
Building, 1301 Constitution Ave., NW., Room 3334, Washington, DC. The 
Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Public 
Reading Room is (202) 566-1744, and the telephone number for the Air 
Docket is (202) 566-1742. NHTSA: Docket Management Facility, M-30, U.S. 
Department of Transportation, West Building, Ground Floor, Rm. W12-140, 
1200 New Jersey Avenue, SE., Washington, DC 20590. The Docket 
Management Facility is open between 9 a.m. and 5 p.m. Eastern Time, 
Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: NHTSA: Lily Smith, Office of Chief 
Counsel, National Highway Traffic Safety Administration, 1200 New 
Jersey Avenue, SE., Washington, DC 20590. Telephone: (202) 366-2992. 
EPA: Lauren Steele, Office of Transportation and Air Quality, 
Assessment and Standards Division (ASD), Environmental Protection 
Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; telephone number: 
(734) 214-4788; fax number: (734) 214-4816; e-mail address: 
steele.lauren@epa.gov, or contact the Office of Transportation and Air 
Quality at OTAQPUBLICWEB@epa.gov.

SUPPLEMENTARY INFORMATION: 

A. Does this action apply to me?

    This action affects companies that manufacture, sell, or import 
into the United States new heavy-duty engines and new Class 2b through 
8 trucks, including combination tractors, school and transit buses, 
vocational vehicles such as utility service trucks, as well as \3/4\-
ton and 1-ton pickup trucks and vans. The heavy-duty category 
incorporates all motor vehicles with a gross vehicle weight rating of 
8,500 pounds or greater, and the engines that power them, except for 
medium-duty passenger vehicles already covered by the greenhouse gas 
emissions standards and corporate average fuel economy standards issued 
for light-duty model year 2012-2016 vehicles. Regulated categories and 
entities include the following:

------------------------------------------------------------------------
                                                        Examples of
           Category              NAICS Code \a\    potentially affected
                                                         entities
------------------------------------------------------------------------
Industry......................            336111  Motor Vehicle
                                          336112   Manufacturers, Engine
                                                   and Truck
                                                   Manufacturers.
                                          336120
Industry......................            541514  Commercial Importers
                                          811112   of Vehicles and
                                                   Vehicle Components.
                                          811198
Industry......................            336111  Alternative Fuel
                                                   Vehicle Converters.
                                          336112

[[Page 57107]]

 
                                          422720
                                          454312
                                          541514
                                          541690
                                          811198
Industry......................            333618  Manufacturers,
                                          336510   remanufacturers and
                                                   importers of
                                                   locomotives and
                                                   locomotive engines.
------------------------------------------------------------------------
Note:
\a\ North American Industry Classification System (NAICS).

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely covered by these rules. 
This table lists the types of entities that the agencies are aware may 
be regulated by this action. Other types of entities not listed in the 
table could also be regulated. To determine whether your activities are 
regulated by this action, you should carefully examine the 
applicability criteria in the referenced regulations. You may direct 
questions regarding the applicability of this action to the persons 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

Table of Contents

A. Does this action apply to me?
I. Overview
    A. Introduction
    B. Building Blocks of the Heavy-Duty National Program
    C. Summary of the Final EPA and NHTSA HD National Program
    D. Summary of Costs and Benefits of the HD National Program
    E. Program Flexibilities
    F. EPA and NHTSA Statutory Authorities
    G. Future HD GHG and Fuel Consumption Rulemakings
II. Final GHG and Fuel Consumption Standards for Heavy-Duty Engines 
and Vehicles
    A. What vehicles will be affected?
    B. Class 7 and 8 Combination Tractors
    C. Heavy-Duty Pickup Trucks and Vans
    D. Class 2b-8 Vocational Vehicles
    E. Other Standards
III. Feasibility Assessments and Conclusions
    A. Class 7-8 Combination Tractor
    B. Heavy-Duty Pickup Trucks and Vans
    C. Class 2b-8 Vocational Vehicles
IV. Final Regulatory Flexibility Provisions
    A. Averaging, Banking, and Trading Program
    B. Additional Flexibility Provisions
V. NHTSA and EPA Compliance, Certification, and Enforcement 
Provisions
    A. Overview
    B. Heavy-Duty Pickup Trucks and Vans
    C. Heavy-Duty Engines
    D. Class 7 and 8 Combination Tractors
    E. Class 2b-8 Vocational Vehicles
    F. General Regulatory Provisions
    G. Penalties
VI. How will this program impact fuel consumption, GHG emissions, 
and climate change?
    A. What methodologies did the agencies use to project GHG 
emissions and fuel consumption impacts?
    B. MOVES Analysis
    C. What are the projected reductions in fuel consumption and GHG 
emissions?
    D. Overview of Climate Change Impacts From GHG Emissions
    E. Changes in Atmospheric CO2 Concentrations, Global 
Mean Temperature, Sea Level Rise, and Ocean pH Associated With the 
Program's GHG Emissions Reductions
VII. How will this final action impact non-ghg emissions and their 
associated effects?
    A. Emissions Inventory Impacts
    B. Health Effects of Non-GHG Pollutants
    C. Environmental Effects of Non-GHG Pollutants
    D. Air Quality Impacts of Non-GHG Pollutants
VIII. What are the agencies' estimated cost, economic, and other 
impacts of the final program?
    A. Conceptual Framework for Evaluating Impacts
    B. Costs Associated With the Final Program
    C. Indirect Cost Multipliers
    D. Cost per Ton of Emissions Reductions
    E. Impacts of Reduction in Fuel Consumption
    F. Class Shifting and Fleet Turnover Impacts
    G. Benefits of Reducing CO2 Emissions
    H. Non-GHG Health and Environmental Impacts
    I. Energy Security Impacts
    J. Other Impacts
    K. The Effect of Safety Standards and Voluntary Safety 
Improvements on Vehicle Weight
    L. Summary of Costs and Benefits
    M. Employment Impacts
IX. Analysis of the Alternatives
    A. What are the alternatives that the agencies considered?
    B. How do these alternatives compare in overall GHG emissions 
reductions and fuel efficiency and cost?
    C. What is the agencies' decision regarding trailer standards?
X. Public Participation
XI. NHTSA's Record of Decision
    A. The Agency's Decision
    B. Alternatives Considered by NHTSA in Reaching Its Decision, 
Including the Environmentally Preferable Alternative
    C. Factors Balanced by NHTSA in Making Its Decision
    D. How the Factors and Considerations Balanced by NHTSA Entered 
Into Its Decision
    E. The Agency's Preferences Among Alternatives Based on Relevant 
Factors, Including Economic and Technical Considerations and Agency 
Statutory Missions
    F. Mitigation
XII. Statutory and Executive Order Reviews
XIII. Statutory Provisions and Legal Authority
    A. EPA
    B. NHTSA

I. Overview

A. Introduction

    EPA and NHTSA (``the agencies'') are announcing a first-ever 
program to reduce greenhouse gas (GHG) emissions and fuel consumption 
in the heavy-duty highway vehicle sector. This broad sector--ranging 
from large pickups to sleeper-cab tractors--together represent the 
second largest contributor to oil consumption and GHG emissions from 
the mobile source sector, after light-duty passenger cars and trucks. 
These are the second joint rules issued by the agencies, following on 
the April 1, 2010 standards to sharply reduce GHG emissions and fuel 
consumption from MY 2012-2016 passenger cars and light trucks 
(published on May 7, 2010 at 75 FR 25324).
    In a May 21, 2010 memorandum to the Administrators of EPA and NHTSA 
(and the Secretaries of Transportation and Energy), the President 
stated that ``America has the opportunity to lead the world in the 
development of a new generation of clean cars and trucks through 
innovative technologies and manufacturing that will spur economic 
growth and create high-quality domestic jobs, enhance our energy 
security, and improve our environment.'' 1 2 In the

[[Page 57108]]

May 2010 memorandum, the President specifically requested the 
Administrators of EPA and NHTSA to ``immediately begin work on a joint 
rulemaking under the Clean Air Act (CAA) and the Energy Independence 
and Security Act of 2007 (EISA) to establish fuel efficiency and 
greenhouse gas emissions standards for commercial medium-and heavy-duty 
on-highway vehicles and work trucks beginning with the 2014 model year 
(MY).'' In this final rulemaking, each agency is addressing this 
Memorandum by adopting rules under its respective authority that 
together comprise a coordinated and comprehensive HD National Program 
designed to address the urgent and closely intertwined challenges of 
reduction of dependence on oil, achievement of energy security, and 
amelioration of global climate change.
---------------------------------------------------------------------------

    \1\ Improving Energy Security, American Competitiveness and Job 
Creation, and Environmental Protection Through a Transformation of 
Our Nation's Fleet of Cars And Trucks,'' Issued May 21, 2010, 
published at 75 FR 29399, May 26, 2010.
    \2\ The May 2010 Presidential Memorandum also directed EPA and 
NHTSA, in close coordination with the California Air Resources 
Board, to build on the National Program for 2012-2016 MY light-duty 
vehicles by developing and proposing coordinated light-duty vehicle 
standards for MY 2017-2025. The agencies have taken an initial step 
in this process, releasing a Joint Notice of Intent and Initial 
Joint Technical Assessment Report in September 2010 (75 FR 62739), 
and a Supplemental Notice of Intent (75 FR 76337). The agencies plan 
to issue a full light-duty vehicle proposal to extend the National 
Program to MY 2017-2025 in September 2011.
---------------------------------------------------------------------------

    At the same time, the final program will enhance American 
competitiveness and job creation, benefit consumers and businesses by 
reducing costs for transporting goods, and spur growth in the clean 
energy sector.
    The HD National Program the agencies are finalizing today reflects 
a collaborative effort between the agencies, a range of public interest 
nongovernmental organizations (NGOs), the state of California and the 
regulated industry. At the time of the President's announcement, a 
number of major HD truck and engine manufacturers representing the vast 
majority of this industry, and the California Air Resources Board 
(California ARB), sent letters to EPA and NHTSA supporting the creation 
of a HD National Program based on a common set of principles. In the 
letters, the stakeholders committed to working with the agencies and 
with other stakeholders toward a program consistent with common 
principles, including:
    Increased use of existing technologies to achieve significant GHG 
emissions and fuel consumption reductions;
    A program that starts in 2014 and is fully phased in by 2018;
    A program that works towards harmonization of methods for 
determining a vehicle's GHG and fuel efficiency, recognizing the global 
nature of the issues and the industry;
    Standards that recognize the commercial needs of the trucking 
industry; and
    Incentives leading to the early introduction of advanced 
technologies.
    The final rules adopted today reflect these principles. The final 
HD National Program also builds on many years of heavy-duty engine and 
vehicle technology development to achieve what the agencies believe is 
the greatest degree of fuel consumption and GHG emission reduction 
appropriate, technologically and economically feasible, and cost-
effective for model years 2014-2018. In addition to taking aggressive 
steps that are reasonably possible now, based on the technological 
opportunities and pathways that present themselves during these model 
years, the agencies and industry will also continue learning about 
emerging opportunities for this complex sector to further reduce fuel 
consumption and GHG emission through future regulatory steps.
    Similarly, the agencies will participate in efforts to improve our 
ability to accurately characterize the actual in-use fuel consumption 
and emissions of this complex sector. As technologies progress in the 
coming years and as the agencies improve the regulatory tools to 
evaluate real world vehicle performance, we expect that we will develop 
a second phase of regulations to reinforce these initial rules and 
achieve further reductions in GHG emissions and fuel consumption 
reduction for the mid- and longer-term time frame (beyond 2018). The 
agencies are committed to working with all interested stakeholders in 
this effort and to the extent possible working towards alignment with 
similar programs being developed in Canada, Mexico, Europe, China, and 
Japan. In doing so, we will continue to evaluate many of the structural 
and technical decisions we are making in today's final action in the 
context of new technologies and the new regulatory tools that we expect 
to realize in the future.
    The regulatory program we are finalizing today is largely unchanged 
from the proposal the agencies made on November 30, 2010 (See 75 FR 
741512). The structure of the program and the stringency of the 
standards are essentially the same as proposed. We have made a number 
of changes to the testing requirements and reporting requirements to 
provide greater regulatory certainty and better align the NHTSA and EPA 
portions of the program. In response to comments, we have also made 
some changes to the averaging, banking and trading (ABT) provisions of 
the program that will make implementation of this final program more 
flexible for manufacturers. We have added provisions to further 
encourage the development of advanced technologies and to provide a 
more straightforward mechanism to certify engines and vehicles using 
innovative technologies. Finally in response to comments, we have made 
some technical changes to our emissions compliance model that results 
in different numeric standards for both combination tractors and 
vocational vehicles to more accurately characterize emissions while 
maintaining the same overall stringency and therefore expected costs 
and benefits of the program.
    Heavy-duty vehicles move much of the nation's freight and carry out 
numerous other tasks, including utility work, concrete delivery, fire 
response, refuse collection, and many more. Heavy-duty vehicles are 
primarily powered by diesel engines, although about 37 percent of these 
vehicles are powered by gasoline engines.\3\ Heavy-duty trucks \4\ have 
long been an important part of the goods movement infrastructure in 
this country and have experienced significant growth over the last 
decade related to increased imports and exports of finished goods and 
increased shipping of finished goods to homes through Internet 
purchases.
---------------------------------------------------------------------------

    \3\ References in this preamble to ``gasoline'' engines (and the 
vehicles powered by them) generally include other Otto-cycle engines 
as well, such as those fueled by ethanol and natural gas, except in 
contexts that are clearly gasoline-specific.
    \4\ In this rulemaking, EPA and NHTSA use the term ``truck'' in 
a general way, referring to all categories of regulated heavy-duty 
highway vehicles (including buses). As such, the term is generally 
interchangeable with ``heavy-duty vehicle.''
---------------------------------------------------------------------------

    The heavy-duty sector is extremely diverse in several respects, 
including types of manufacturing companies involved, the range of sizes 
of trucks and engines they produce, the types of work the trucks are 
designed to perform, and the regulatory history of different 
subcategories of vehicles and engines. The current heavy-duty fleet 
encompasses vehicles from the ``18-wheeler'' combination tractors one 
sees on the highway to school and transit buses, to vocational vehicles 
such as utility service trucks, as well as the largest pickup trucks 
and vans.
    For purposes of this preamble, the term ``heavy-duty'' or ``HD'' is 
used to apply to all highway vehicles and engines that are not within 
the range of light-duty vehicles, light-duty trucks, and medium-duty 
passenger vehicles (MDPV) covered by the GHG and Corporate Average Fuel 
Economy (CAFE) standards issued for MY 2012-2016.\5\ It also does not 
include

[[Page 57109]]

motorcycles. Thus, in this rulemaking, unless specified otherwise, the 
heavy-duty category incorporates all vehicles with a gross vehicle 
weight rating above 8,500 pounds, and the engines that power them, 
except for MDPVs.\6\
---------------------------------------------------------------------------

    \5\ Light-Duty Vehicle Greenhouse Gas Emission Standards and 
Corporate Average Fuel Economy Standards; Final Rule 75 FR 25323, 
May 7, 2010.
    \6\ The CAA defines heavy-duty as a truck, bus or other motor 
vehicles with a gross vehicle weight rating exceeding 6,000 pounds 
(CAA section 202(b)(3)). The term HD as used in this action refers 
to a subset of these vehicles and engines.
---------------------------------------------------------------------------

    The agencies proposed to cover all segments of the heavy-duty 
category above, except with respect to recreational vehicles (RVs or 
motor homes). We note that the Energy Independence and Security Act of 
2007 requires NHTSA to set standards for ``commercial medium- and 
heavy-duty on-highway vehicles and work trucks.'' \7\ The standards 
that EPA is finalizing today cover recreational on-highway vehicles, 
while NHTSA proposed not to include recreational vehicles based on an 
interpretation of the term ``commercial medium- and heavy-duty on-
highway commercial'' vehicles. NHTSA stated in the NPRM that 
recreational vehicles are non-commercial, and therefore outside of the 
term and the scope of its rule.
---------------------------------------------------------------------------

    \7\ 49 U.S.C. 32902(k)(2). ``Commercial medium- and heavy-duty 
on-highway vehicles'' are defined as on-highway vehicles with a 
gross vehicle weight rating of 10,000 pounds or more, while ``work 
trucks'' are defined as vehicles rated between 8,500 and 10,000 
pounds gross vehicle weight that are not MDPVs. See 49 U.S.C. 
32901(a)(7) and (a)(19).
---------------------------------------------------------------------------

    Oshkosh Corporation commented that this interpretation did not 
match the statutory definition of the term in EISA, which defines 
``commercial medium- and heavy-duty on-highway vehicle'' by weight 
only,\8\ and that therefore the agency's interpretation of the term 
should be explicitly broadened to include all vehicles, and more than 
only vehicles that are not engaged in interstate commerce as defined by 
the Federal Motor Carrier Safety Administration in 49 CFR part 202. 
Alternatively, Oshkosh suggested that if NHTSA followed the definition 
provided in EISA, which makes no direct reference to the concept of 
``commercial,'' there would be no logical reason to exclude RVs based 
on that definition.
---------------------------------------------------------------------------

    \8\ See 49 U.S.C. 32902(k)(2), Note 7 above.
---------------------------------------------------------------------------

    NHTSA has considered Oshkosh's comment and reconsidered its 
interpretation that effectively read words into the statutory 
definition. Given the very wide variety of vehicles contained in the HD 
fleet, reading those words into the definition and thereby excluding 
certain types of vehicles could create illogical results, i.e., 
treating similar vehicles differently. Therefore, NHTSA will adhere to 
the statutory definition contained in EISA for this rulemaking. 
However, as RVs were not included by NHTSA in the proposed regulation 
in the NPRM, they are not within the scope and must be excluded in 
NHTSA's portion of the final program. Accordingly, NHTSA will address 
this issue in the next rulemaking. However, as noted, RVs are subject 
to the CO2 standards for vocational vehicles.
    Setting fuel consumption standards for the heavy-duty sector, 
pursuant to NHTSA's EISA authority, will also improve our energy and 
national security by reducing our dependence on foreign oil, which has 
been a national objective since the first oil price shocks in the 
1970s. Net petroleum imports now account for approximately 49-51 
percent of U.S. petroleum consumption. World crude oil production is 
highly concentrated, exacerbating the risks of supply disruptions and 
price shocks as the recent unrest in North Africa and the Persian Gulf 
highlights. Recently, oil prices have been over $100 per barrel, 
gasoline and diesel fuel prices in excess of $4 per gallon, causing 
financial hardship for many families and businesses. The export of U.S. 
assets in exchange for oil imports continues to be an important 
component of the historically unprecedented U.S. trade deficits. 
Transportation accounts for about 72 percent of U.S. petroleum 
consumption. Heavy-duty vehicles account for about 17 percent of 
transportation oil use, which means that they alone account for about 
12 percent of all U.S. oil consumption.\9\
---------------------------------------------------------------------------

    \9\ In 2009 Source: EIA Annual Energy Outlook 2010 released May 
11, 2010.
---------------------------------------------------------------------------

    Setting GHG emissions standards for the heavy-duty sector will help 
to ameliorate climate change. The EPA Administrator found after a 
thorough examination of the scientific evidence on the causes and 
impact of current and future climate change, and careful review of 
public comments, that the science compellingly supports a positive 
finding that atmospheric concentrations of six greenhouse gases taken 
in combination result in air pollution which may reasonably be 
anticipated to endanger both public health and welfare and that the 
combined emissions of these greenhouse gases from new motor vehicles 
and engines contributes to the greenhouse gas air pollution that 
endangers public health and welfare. In her finding, the Administrator 
carefully studied and relied heavily upon the major findings and 
conclusions from the recent assessments of the U.S. Climate Change 
Science Program and the U.N. Intergovernmental Panel on Climate Change. 
74 FR 66496, December 15, 2009. As summarized in the Technical Support 
Document for EPA's Endangerment and Cause or Contribute Findings under 
section 202(a) of the Clean Air Act, anthropogenic emissions of GHGs 
are very likely (a 90 to 99 percent probability) the cause of most of 
the observed global warming over the last 50 years.\10\ Primary GHGs of 
concern are carbon dioxide (CO2), methane (CH4), 
nitrous oxide (N2O), hydrofluorocarbons (HFCs), 
perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). 
Mobile sources emitted 31 percent of all U.S. GHGs in 2007 
(transportation sources, which do not include certain off-highway 
sources, account for 28 percent) and have been the fastest-growing 
source of U.S. GHGs since 1990.\11\ Mobile sources addressed in EPA's 
endangerment and contribution findings under CAA section 202(a)--light-
duty vehicles, heavy-duty trucks, buses, and motorcycles--accounted for 
23 percent of all U.S. GHG emissions in 2007.\12\ Heavy-duty vehicles 
emit CO2, CH4, N2O, and HFCs and are 
responsible for nearly 19 percent of all mobile source GHGs (nearly 6 
percent of all U.S. GHGs) and about 25 percent of section 202(a) mobile 
source GHGs. For heavy-duty vehicles in 2007, CO2 emissions 
represented more than 99 percent of all GHG emissions (including 
HFCs).\13\
---------------------------------------------------------------------------

    \10\ U.S. EPA. (2009). ``Technical Support Document for 
Endangerment and Cause or Contribute Findings for Greenhouse Gases 
Under Section 202(a) of the Clean Air Act'' Washington, DC, 
available at Docket: EPA-HQ-OAR-2009-0171-11645, and at http://epa.gov/climatechange/endangerment.html.
    \11\ U.S. Environmental Protection Agency. 2009. Inventory of 
U.S. Greenhouse Gas Emissions and Sinks: 1990-2007. EPA 430-R-09-
004. Available at http://epa.gov/climatechange/emissions/downloads09/GHG2007entire_report-508.pdf.
    \12\ See Endangerment TSD, Note 10, above, at pp. 180-194.
    \13\ U.S. Environmental Protection Agency. 2009. Inventory of 
U.S. Greenhouse Gas Emissions and Sinks: See Note 11, above.
---------------------------------------------------------------------------

    In developing this HD National program, the agencies have worked 
with a large and diverse group of stakeholders representing truck and 
engine manufacturers, trucking fleets, environmental organizations, and 
states including the State of California.\14\ Further, it is our 
expectation based on our ongoing work with the State of California that 
the California ARB will

[[Page 57110]]

be able to adopt regulations equivalent in practice to those of this HD 
National Program, just as it has done for past EPA regulation of heavy-
duty trucks and engines. NHTSA and EPA have been working with 
California ARB to enable that outcome.
---------------------------------------------------------------------------

    \14\ Pursuant to DOT Order 2100.2, NHTSA has docketed a 
memorandum recording those meetings that it attended and documents 
submitted by stakeholders which formed a basis for this action and 
which can be made publicly available in its docket for this 
rulemaking. DOT Order 2100.2 is available at http://www.reg-group.com/library/DOT2100-2.PDF.
---------------------------------------------------------------------------

    In light of the industry's diversity, and consistent with the 
recommendations of the National Academy of Sciences (NAS) as discussed 
further below, the agencies are adopting a HD National Program that 
recognizes the different sizes and work requirements of this wide range 
of heavy-duty vehicles and their engines. NHTSA's final fuel 
consumption standards and EPA's final GHG standards apply to 
manufacturers of the following types of heavy-duty vehicles and their 
engines; the final provisions for each of these are described in more 
detail below in this section:
     Heavy-duty Pickup Trucks and Vans.
     Combination Tractors.
     Vocational Vehicles.
    As in the light-duty 2012-2016 MY vehicle rule, EPA's and NHTSA's 
final standards for the heavy-duty sector are largely harmonized with 
one another due to the close and direct relationship between improving 
the fuel efficiency of these vehicles and reducing their CO2 
tailpipe emissions. For all vehicles that consume carbon-based fuels, 
the amount of CO2 exhaust emissions is essentially constant 
per gallon for a given type of fuel that is consumed. The more 
efficient a heavy-duty truck is in completing its work, the lower its 
environmental impact will be, because the less fuel consumed to move 
cargo a given distance, the less CO2 that truck emits 
directly into the air. The technologies available for improving fuel 
efficiency, and therefore for reducing both CO2 emissions 
and fuel consumption, are one and the same.\15\ Because of this close 
technical relationship, NHTSA and EPA have been able to rely on 
jointly-developed assumptions, analyses, and analytical conclusions to 
support the standards and other provisions that NHTSA and EPA are 
adopting under our separate legal authorities.
---------------------------------------------------------------------------

    \15\ However, as discussed below, in addition to addressing 
CO2, the EPA's final standards also include provisions to 
address other GHGs (nitrous oxide, methane, and air conditioning 
refrigerant emissions). See Section II.
---------------------------------------------------------------------------

    This program is based on standards for direct exhaust emissions 
from engines and vehicles. In characterizing the overall emissions 
impacts, benefits and costs of the program, analyses of air pollutant 
emissions from upstream sources have been conducted. In this action, 
the agencies use the term upstream to include emissions from the 
production and distribution of fuel. A summary of the analysis of 
upstream emissions can be found in Section VI.C of this preamble, and 
further details are available in Chapter 5 of the RIA.
    The timelines for the implementation of the final NHTSA and EPA 
standards are also closely coordinated. EPA's final GHG emission 
standards will begin in model year 2014. In order to provide for the 
four full model years of regulatory lead time required by EISA, as 
discussed in Section 0 below, NHTSA's final fuel consumption standards 
will be voluntary in model years 2014 and 2015, becoming mandatory in 
model year 2016, except for diesel engine standards which will be 
voluntary in model years 2014, 2015 and 2016, becoming mandatory in 
model year 2017. Both agencies are also allowing for early compliance 
in model year 2013. A detailed discussion of how the final standards 
are consistent with each agency's respective statutory requirements and 
authorities is found later in this preamble.
    Allison Transmission stated that sufficient time must be taken 
before issuing the final rules in order to ensure that the standards 
are supportable. As explained in Sections II and III below, as well as 
in the RIA, the agencies believe there is sufficient lead time to meet 
all of the standards adopted in today's rules. For those areas for 
which the agencies have determined that insufficient time is available 
to develop appropriate standards, such as for trailers, the agencies 
are not including regulations as part of this initial program.
    NHTSA received several comments related to the timing of the 
implementation of its fuel consumption standards. The Engine 
Manufacturers Association (EMA), the National Automobile Dealers 
Association (NADA), The Volvo Group (Volvo), and Navistar argued that 
the timing of NHTSA's standards violated the lead time requirement of 
49 U.S.C. 32902(k)(3)(A), which states that standards under the new 
medium- and heavy-duty program shall have ``not less than 4 full model 
years of regulatory lead-time.'' The commenters seemed to interpret the 
voluntary program as the imposition of regulation upon industry. NADA 
described NHTSA's standards during the voluntary period as 
``mandates.''
    NHTSA has reviewed this issue and believes that the regulatory 
schedule is consistent with the lead time requirement of Section 
32902(k)(3). To clarify, NHTSA will not be imposing a mandatory 
regulatory program until 2016, and none of the voluntary standards will 
be ``mandates.'' As described in later sections, the voluntary 
standards would only apply to a manufacturer if it makes the voluntary 
and affirmative choice to opt-in to the program. \16\ Mandatory NHTSA 
standards will first come into effect in 2016, giving industry four 
full years of lead time with the NHTSA fuel consumption standards.
---------------------------------------------------------------------------

    \16\ Prior to or at the same time that a manufacturer submits 
its first application for a certificate of conformity; See Section V 
below.
---------------------------------------------------------------------------

    EMA, NADA, and Navistar also argued that the proposed standards 
would violate the stability requirement of 49 U.S.C. 32902(k)(3)(B), 
which states that they shall have ``not less than 3 full model years of 
regulatory stability.'' EMA stated that since there are HD emission 
standards taking effect in 2013, the 2014 implementation date for this 
rule would violate the stability requirements. NADA argued that the MY 
2014-2017/2018 phase-in period was inadequate to fulfill the stability 
requirement.
    Congress has not spoken directly to the meaning of the words 
``regulatory stability.'' NHTSA believes that the ``regulatory 
stability'' requirement exists to ensure that manufacturers will not be 
subject to new standards in repeated rulemakings too rapidly, given 
that Congress did not include a minimum duration period for the MD/HD 
standards.\17\ NHTSA further believes that standards, which as set 
provide for increasing stringency during the period that the standards 
are applicable under this rule to be the maximum feasible during the 
regulatory period, are within the meaning of the statute. In this 
statutory context, NHTSA interprets the phrase ``regulatory stability'' 
in Section 32902(k)(3)(B) as requiring that the standards remain in 
effect for three years before they may be increased by amendment. It 
does not prohibit standards which contain pre-determined stringency 
increases.
---------------------------------------------------------------------------

    \17\ In contrast, light-duty standards must remain in place for 
``at least 1, but not more than 5, model years.'' 23902(b)(3)(B).
---------------------------------------------------------------------------

    As laid out in Section II below, NHTSA's final standards follow 
different phase-in schedules based on differences between the 
regulatory categories. Consistent with NHTSA's statutory obligation to 
implement a program designed to achieve the maximum feasible fuel 
efficiency improvement, the standards increase in stringency based upon 
increasing fleet penetration rates for the available technologies. The 
NPRM proposed phase-in schedules aligned with EPA's,

[[Page 57111]]

some of which followed pre-determined stringency increases. The NPRM 
also noted that NHTSA was considering alternate standards that would 
not change in stringency during the time frame when the regulations are 
effective for those standards that increased throughout the mandatory 
program. As described in Section II below, the final rule includes the 
proposed alternate standards for those standards that follow such a 
stringency phase-in path. Therefore, NHTSA believes that the final rule 
provides ample stability for each standard.
    Each standard, associated phase-in schedule, and alternative 
standard implemented by this final rule was noticed in the NPRM. Those 
fuel consumption standards that become mandatory in 2017 will remain in 
effect through at least 2019. This further ensures that the fuel 
consumption standards in this rule will remain in effect for at least 
three years, providing the statutorily-mandated three full years of 
regulatory stability, and ensuring that manufacturers will not be 
subject to new or amended standards too rapidly. (The greenhouse gas 
emission standards remain in effect unless and until amended in all 
later model years in any case.) Therefore, NHTSA believes the 
commenters' concern about regulatory stability is addressed in the 
structure of the rule.
    Neither EPA nor NHTSA is adopting standards at this time for GHG 
emissions or fuel consumption, respectively, for heavy-duty commercial 
trailers or for vehicles or engines manufactured by small businesses. 
The agencies recognize that aerodynamic and tire rolling resistance 
improvements to trailers represent a significant opportunity to reduce 
fuel consumption and GHGs as evidenced, among other things, by the work 
of the EPA SmartWay program. While we are deferring action today on 
setting trailer standards, the agencies are committed to moving forward 
to create a regulatory program for trailers that would complement the 
current vehicle program. See Section IX for more details on the 
agencies' decisions regarding trailers, and Sections II and XII for 
more details on the agencies' decisions regarding small businesses.
    The agencies have analyzed in detail the projected costs, fuel 
savings, and benefits of the final GHG and fuel consumption standards. 
Table I-1 shows estimated lifetime discounted program costs (including 
technological outlays), fuel savings, and benefits for all heavy-duty 
vehicles projected to be sold in model years 2014-2018 over these 
vehicles' lives. Section I.D includes additional information about this 
analysis.

 Table I-1--Estimated Lifetime Discounted Costs, Fuel Savings, Benefits,
    and Net Benefits for 2014-2018 Model Year Heavy-Duty Vehicles a b
                            [Billions, 2009$]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
              Lifetime Present Value \c\--3% Discount Rate
------------------------------------------------------------------------
Program Costs..................................................     $8.1
Fuel Savings...................................................       50
Benefits.......................................................      7.3
Net Benefits\d\................................................       49
------------------------------------------------------------------------
                 Annualized Value \e\--3% Discount Rate
------------------------------------------------------------------------
Annualized Costs...............................................      0.4
Fuel Savings...................................................      2.2
Annualized Benefits............................................      0.4
Net Benefits \d\...............................................      2.2
------------------------------------------------------------------------
              Lifetime Present Value \c\--7% Discount Rate
------------------------------------------------------------------------
Program Costs..................................................      8.1
Fuel Savings...................................................       34
Benefits.......................................................      6.7
Net Benefits \d\...............................................       33
------------------------------------------------------------------------
                 Annualized Value \e\--7% Discount Rate
------------------------------------------------------------------------
Annualized Costs...............................................      0.6
Fuel Savings...................................................      2.6
Annualized Benefits............................................      0.5
Net Benefits \d\...............................................      2.5
------------------------------------------------------------------------
Notes:
a The agencies estimated the benefits associated with four different
  values of a one ton CO2 reduction (model average at 2.5% discount
  rate, 3%, and 5%; 95th percentile at 3%), which each increase over
  time. For the purposes of this overview presentation of estimated
  costs and benefits, however, we are showing the benefits associated
  with the marginal value deemed to be central by the interagency
  working group on this topic: the model average at 3% discount rate, in
  2009 dollars. Section VIII.F provides a complete list of values for
  the 4 estimates.
b Note that net present value of reduced GHG emissions is calculated
  differently than other benefits. The same discount rate used to
  discount the value of damages from future emissions (SCC at 5, 3, and
  2.5 percent) is used to calculate net present value of SCC for
  internal consistency. Refer to Section VIII.F for more detail.
c Present value is the total, aggregated amount that a series of
  monetized costs or benefits that occur over time is worth now (in year
  2009 dollar terms), discounting future values to the present.
d Net benefits reflect the fuel savings plus benefits minus costs.
e The annualized value is the constant annual value through a given time
  period (2012 through 2050 in this analysis) whose summed present value
  equals the present value from which it was derived.

B. Building Blocks of the Heavy-Duty National Program

    The standards that are being adopted in this notice represent the 
first time that NHTSA and EPA are regulating the heavy-duty sector for 
fuel consumption and GHG emissions, respectively. The HD National 
Program is rooted in EPA's prior regulatory history, the SmartWay[reg] 
Transport Partnership program, and extensive technical and engineering 
analyses done at the federal level. This section summarizes some of the 
most important of these precursors and foundations for this HD National 
Program.
(1) EPA's Traditional Heavy-Duty Regulatory Program
    Since the 1980s, EPA has acted several times to address tailpipe 
emissions of criteria pollutants and air toxics from heavy-duty 
vehicles and engines. During the last 18 years, these programs have 
primarily addressed emissions of particulate matter (PM) and the 
primary ozone precursors, hydrocarbons (HC) and oxides of nitrogen 
(NOX). These programs have successfully achieved significant 
and cost-effective reductions in emissions and associated health and 
welfare benefits to the nation. They have been structured in ways that 
account for the varying circumstances of the engine and truck 
industries. As required by the CAA, the emission standards implemented 
by these programs include standards that apply at the time that the 
vehicle or engine is sold as well as standards that apply in actual 
use. As a result of these programs, new vehicles meeting current 
emission standards will emit 98 percent less NOX and 99 
percent less PM than new trucks 20 years ago. The resulting emission 
reductions provide significant public health and welfare benefits. The 
most recent EPA regulations which were fully phased-in in 2010, the 
monetized health and welfare benefits alone are projected to be greater 
than $70 billion in 2030--benefits far exceeding compliance costs and 
not including the unmonetized benefits resulting from reductions in air 
toxics and ozone precursors (66 FR 5002, January 18, 2001).
    EPA's overall program goal has always been to achieve emissions 
reductions from the complete vehicles that operate on our roads. The 
agency has often accomplished this goal for many heavy-duty truck 
categories through the regulation of heavy-duty engine emissions. A key 
part of this success has been the development over many years of a 
well-established, representative, and robust set of engine

[[Page 57112]]

test procedures that industry and EPA now routinely use to measure 
emissions and determine compliance with emission standards. These test 
procedures in turn serve the overall compliance program that EPA 
implements to help ensure that emissions reductions are being achieved. 
By isolating the engine from the many variables involved when the 
engine is installed and operated in a HD vehicle, EPA has been able to 
accurately address the contribution of the engine alone to overall 
emissions. The agencies discuss below how the final program 
incorporates the existing engine-based approach used for criteria 
pollutant regulations, as well as new vehicle-based approaches.
(2) NHTSA's Responsibilities To Regulate Heavy-Duty Fuel Efficiency 
under EISA
    With the passage of the EISA in December 2007, Congress laid out a 
framework developing the first fuel efficiency regulations for HD 
vehicles. As codified at 49 U.S.C. 32902(k), EISA requires NHTSA to 
develop a regulatory system for the fuel efficiency of commercial 
medium-duty and heavy-duty on-highway vehicles and work trucks in three 
steps: a study by NAS, a study by NHTSA,\18\ and a rulemaking to 
develop the regulations themselves.
---------------------------------------------------------------------------

    \18\ Factors and Considerations for Establishing a Fuel 
Efficiency Regulatory Program for Commercial Medium- and Heavy-Duty 
Vehicles, October 2010, available at http://www.nhtsa.gov/staticfiles/rulemaking/pdf/cafe/NHTSA_Study_Trucks.pdf.
---------------------------------------------------------------------------

    Specifically, section 102 of EISA, codified at 49 U.S.C. 
32902(k)(2), states that not later than two years after completion of 
the NHTSA study, DOT (by delegation, NHTSA), in consultation with the 
Department of Energy (DOE) and EPA, shall develop a regulation to 
implement a ``commercial medium-duty and heavy-duty on-highway vehicle 
and work truck fuel efficiency improvement program designed to achieve 
the maximum feasible improvement.'' NHTSA interprets the timing 
requirements as permitting a regulation to be developed earlier, rather 
than as requiring the agency to wait a specified period of time.
    Congress specified that as part of the ``HD fuel efficiency 
improvement program designed to achieve the maximum feasible 
improvement,'' NHTSA must adopt and implement:
    Appropriate test methods;
    Measurement metrics;
    Fuel economy standards; \19\ and
---------------------------------------------------------------------------

    \19\ In the context of 49 U.S.C. 32902(k), NHTSA interprets 
``fuel economy standards'' as referring not specifically to miles 
per gallon, as in the light-duty vehicle context, but instead more 
broadly to account as accurately as possible for MD/HD fuel 
efficiency. While it is a metric that NHTSA considered for setting 
MD/HD fuel efficiency standards, the agency recognizes that miles 
per gallon may not be an appropriate metric given the work that MD/
HD vehicles are manufactured to do. NHTSA is thus finalizing 
alternative metrics as discussed further below.
---------------------------------------------------------------------------

    Compliance and enforcement protocols.
    Congress emphasized that the test methods, measurement metrics, 
standards, and compliance and enforcement protocols must all be 
appropriate, cost-effective, and technologically feasible for 
commercial medium-duty and heavy-duty on-highway vehicles and work 
trucks. NHTSA notes that these criteria are different from the ``four 
factors'' of 49 U.S.C. 32902(f) \20\ that have long governed NHTSA's 
setting of fuel economy standards for passenger cars and light trucks, 
although many of the same issues are considered under each of these 
provisions.
---------------------------------------------------------------------------

    \20\ 49 U.S.C. 32902(f) states that ``When deciding maximum 
feasible average fuel economy under this section, [NHTSA] shall 
consider technological feasibility, economic practicability, the 
effect of other motor vehicle standards of the Government on fuel 
economy, and the need of the United States to conserve energy.''
---------------------------------------------------------------------------

    Congress also stated that NHTSA may set separate standards for 
different classes of HD vehicles, which the agency interprets broadly 
to allow regulation of HD engines in addition to HD vehicles, and 
provided requirements new to 49 U.S.C. 32902 in terms of timing of 
regulations, stating that the standards adopted as a result of the 
agency's rulemaking shall provide not less than four full model years 
of regulatory lead time, and three full model years of regulatory 
stability.
(3) National Academy of Sciences Report on Heavy-Duty Technology
    In April 2010 as mandated by Congress in EISA, the National 
Research Council (NRC) under NAS issued a report to NHTSA and to 
Congress evaluating medium-duty and heavy-duty truck fuel efficiency 
improvement opportunities, titled ``Technologies and Approaches to 
Reducing the Fuel Consumption of Medium- and Heavy-duty Vehicles.'' 
\21\ This study covers the same universe of heavy-duty vehicles that is 
the focus of this final rulemaking--all highway vehicles that are not 
light-duty, MDPVs, or motorcycles. The agencies have carefully 
evaluated the research supporting this report and its recommendations 
and have incorporated them to the extent practicable in the development 
of this rulemaking.
---------------------------------------------------------------------------

    \21\ Committee to Assess Fuel Economy Technologies for Medium- 
and Heavy-Duty Vehicles; National Research Council; Transportation 
Research Board (2010). ``Technologies and Approaches to Reducing the 
Fuel Consumption of Medium- and Heavy-Duty Vehicles,'' (hereafter, 
``NAS Report''). Washington, DC, The National Academies Press. 
Available electronically from the National Academies Press Website 
at http://www.nap.edu/catalog.php?record_id=12845 (last accessed 
September 10, 2010).
---------------------------------------------------------------------------

    The NAS report is far reaching in its review of the technologies 
that are available and which may become available in the future to 
reduce fuel consumption from medium and heavy-duty vehicles. In 
presenting the full range of technical opportunities the report 
includes technologies which may not be available until 2020 or even 
further into the future. As such, the report provides not only a 
valuable list of off the shelf technologies from which the agencies 
have drawn in developing this near-term 2014-2018 program consistent 
with statutory authorities and with the set of principles set forth by 
the President, but the report also provides a road map the agencies can 
use as we look to develop future regulations for this sector. A review 
of the technologies in the NAS report makes clear that there are not 
only many technologies readily available today to achieve important 
reductions in fuel consumption, like the ones we used in developing the 
2014-2018 program, but there are also great opportunities for even 
larger reductions in the future through the development of advanced 
hybrid drive systems and sophisticated engine technologies such as 
Rankine waste heat recovery. The agencies will again make extensive use 
of this report when we move forward to develop the next phase of 
regulations for medium and heavy-duty vehicles.
    Allison Transmission commented that NHTSA (implicitly, both 
agencies) had improperly relied on the NAS report and failed to do 
sufficient independent analysis, which Allison claimed did not meet the 
statutory obligation to provide an adequate basis for the rule. First, 
an agency does not improperly delegate its authority or judgment merely 
by using work performed by outside parties as the factual basis for its 
decision making. See U.S. Telecom Ass'n v. FCC, 359 F.3d 554, 568 (DC 
Cir. 2004); United Steelworkers of Am. v. Marshall, 647 F.2d 1189, 
1216-17 (DC Cir. 1980). Here, although EPA and NHTSA carefully 
considered the NAS report, the agencies' consideration and use of the 
report was not uncritical and the agencies exercised reasonable 
independent judgment in developing the proposed and final rules. 
Consistent with EISA's direction, NAS submitted a report evaluating MD/
HD fuel economy standards to NHTSA in March of 2010.

[[Page 57113]]

Indeed, many commenters argued that the agencies should have adopted 
more of the NAS report recommendations. The agencies reviewed the 
findings and recommendations of the NAS report when developing the 
proposed rules, as was clearly intended by Congress, but also conducted 
an independent study, as described throughout the record to the 
proposal and summarized in Section X of the NPRM, 75 FR at 74351-56. In 
conducting its analysis of the NAS report, the agencies found that 
several key recommendations, such as the use of fuel efficiency 
metrics, were the best approach to implementing the new program. 
However, the agencies rejected other recommendations of the NAS report, 
for example, by proposing separate regulation of engines and vehicles 
and the regulation of large manufacturers.
(4) The NHTSA and EPA Light-Duty National GHG and Fuel Economy Program
    On May 7, 2010, EPA and NHTSA finalized the first-ever National 
Program for light-duty cars and trucks, which set GHG emissions and 
fuel economy standards for model years 2012-2016 (See 75 FR 25324). The 
agencies have used the light-duty National Program as a model for this 
final HD National Program in many respects. This is most apparent in 
the case of heavy-duty pickups and vans, which are very similar to the 
light-duty trucks addressed in the light-duty National Program both 
technologically as well as in terms of how they are manufactured (i.e., 
the same company often makes both the vehicle and the engine). For 
these vehicles, there are close parallels to the light-duty program in 
how the agencies have developed our respective final standards and 
compliance structures, although, as discussed below, the technologies 
applied to light-duty trucks are not invariably applicable to heavy-
duty pickups and vans at the same penetration rates in the lead time 
afforded in this heavy-duty action. Another difference is that each 
agency adopts standards based on attributes other than vehicle 
footprint, as discussed below.
    Due to the diversity of the remaining HD vehicles, there are fewer 
parallels with the structure of the light-duty program. However, the 
agencies have maintained the same collaboration and coordination that 
characterized the development of the light-duty program. Most notably, 
as with the light-duty program, manufacturers will be able to design 
and build vehicles to meet a closely coordinated, harmonized national 
program, and avoid unnecessarily duplicative testing and compliance 
burdens.
(5) EPA's SmartWay Program
    EPA's voluntary SmartWay Transport Partnership program encourages 
shipping and trucking companies to take actions that reduce fuel 
consumption and CO2 by working with the shipping community 
and the freight sector to identify low carbon strategies and 
technologies, and by providing technical information, financial 
incentives, and partner recognition to accelerate the adoption of these 
strategies. Through the SmartWay program, EPA has worked closely with 
truck manufacturers and truck fleets to develop test procedures to 
evaluate vehicle and component performance in reducing fuel consumption 
and has conducted testing and has established test programs to verify 
technologies that can achieve these reductions. Over the last six 
years, EPA has developed hands-on experience testing the largest heavy-
duty trucks and evaluating improvements in tire and vehicle aerodynamic 
performance. In 2010, according to vehicle manufacturers, approximately 
five percent of new combination heavy-duty trucks will meet the 
SmartWay performance criteria demonstrating that they represent the 
pinnacle of current heavy-duty truck reductions in fuel consumption.
    In developing this HD National Program, the agencies have drawn 
from the SmartWay experience, as discussed in detail both in Sections 
II and III below (e.g., developing test procedures to evaluate trucks 
and truck components) but also in the RIA (estimating performance 
levels from the application of the best available technologies 
identified in the SmartWay program). These technologies provide part of 
the basis for the GHG emission and fuel consumption standards in this 
rulemaking for certain types of new heavy-duty Class 7 and 8 
combination tractors.
    In addition to identifying technologies, the SmartWay program 
includes operational approaches that truck fleet owners as well as 
individual drivers and their freight customers can incorporate, that 
the NHTSA and EPA believe will complement the final standards. These 
include such approaches as improved logistics and driver training, as 
discussed in the RIA. This approach is consistent with the one of the 
three alternative approaches that the NAS recommended be considered. 
The three approaches were raising fuel taxes, relaxing truck size and 
weight restrictions, and encouraging incentives to disseminate 
information to inform truck drivers about the relationship between 
driving behavior and fuel savings. Taxes and truck size and weight 
limits are mandated by public law; as such, these options are outside 
EPA's and NHTSA's authority to implement. However, complementary 
operational measures like driver training, which SmartWay does promote, 
can complement the final standards and also provide benefits for the 
existing truck fleet, furthering the public policy objectives of 
addressing energy security and climate change.
(6) Environment Canada
    The Government of Canada's Department of the Environment 
(Environment Canada) assisted EPA's development of this rulemaking by 
conducting emissions testing of heavy-duty vehicles at their test 
facilities to gather data on a range of possible test cycles, and to 
evaluate the impact of certain emissions reduction technologies. 
Environment Canada also facilitated the evaluation of heavy-duty 
vehicle aerodynamic properties at Canada's National Research Council 
wind tunnel, and during coastdown testing.
    We expect the technical collaboration with Environment Canada to 
continue as we implement testing and compliance verification procedures 
for this rulemaking. We may also begin to develop a knowledge base 
enabling improvement upon this regulatory framework for model years 
beyond 2018 (for example, improvements to the means of demonstrating 
compliance). We also expect to continue our collaboration with 
Environment Canada on compliance issues.
    Collaboration with Environment Canada is taking place under the 
Canada-U.S. Air Quality Committee.

C. Summary of the Final EPA and NHTSA HD National Program

    When EPA first addressed emissions from heavy-duty trucks in the 
1980s, it established standards for engines, based on the amount of 
work performed (grams of pollutant per unit of work, expressed as grams 
per brake horsepower-hour or g/bhp-hr).\22\ This

[[Page 57114]]

approach recognized the fact that engine characteristics are the 
dominant determinant of the types of emissions generated, and engine-
based technologies (including exhaust aftertreatment systems) need to 
be the focus for addressing those emissions. Vehicle-based 
technologies, in contrast, have less influence on overall truck 
emissions of the pollutants that EPA has regulated in the past. The 
engine testing approach also recognized the relatively small number of 
distinct heavy-duty engine designs, as compared to the extremely wide 
range of truck designs. EPA concluded at that time that any incremental 
gain in conventional emission control that could be achieved through 
regulation of the complete vehicle would be small in comparison to the 
cost of addressing the many variants of complete trucks that make up 
the heavy-duty sector--smaller and larger vocational vehicles for 
dozens of purposes, various designs of combination tractors, and many 
others.
---------------------------------------------------------------------------

    \22\ The term ``brake power'' refers to engine torque and power 
as measured at the interface between the engine's output shaft and 
the dynamometer. This contrasts with ``indicated power'', which is a 
calculated value based on the pressure dynamics in the combustion 
chamber, not including internal losses that occur due to friction 
and pumping work. Since the measurement procedure inherently 
measures brake torque and power, the final regulations refer simply 
to g/hp-hr. This is consistent with EPA's other emission control 
programs, which generally include standards in g/kW-hr.
---------------------------------------------------------------------------

    Addressing GHG emissions and fuel consumption from heavy-duty 
trucks, however, requires a different approach. Reducing GHG emissions 
and fuel consumption requires increasing the inherent efficiency of the 
engine as well as making changes to the vehicles to reduce the amount 
of work demanded from the engine in order to move the truck down the 
road. A focus on the entire vehicle is thus required. For example, in 
addition to the basic emissions and fuel consumption levels of the 
engine, the aerodynamics of the vehicle can have a major impact on the 
amount of work that must be performed to transport freight at common 
highway speeds. For this first rulemaking, the agencies proposed a 
complementary engine and vehicle approach in order to achieve the 
maximum feasible near-term reductions.
    NHTSA received comments on the proposal to create complementary 
engine and vehicle standards. Volvo and Daimler argued that EISA 
limited NHTSA's authority to the regulation of completed vehicles and 
did not give NHTSA authority to regulate engines. 49 U.S.C. 32902(k)(2) 
grants NHTSA broad authority to regulate this sector, stating simply 
that the Secretary ``shall determine in a rulemaking proceeding how to 
implement a commercial medium- and heavy-duty on-highway vehicle and 
work truck fuel efficiency improvement program designed to achieve the 
maximum feasible improvement,'' considering appropriateness, cost-
effectiveness, and technological feasibility. NHTSA does not believe 
that this language precludes the regulation of engines, but rather 
explicitly leaves the regulatory approach to the agency's expertise and 
discretion. See 75 FR at 74173 n. 36. Considering the factors described 
in the NPRM and in Sections III and IV below, NHTSA continues to 
believe that the separate regulation of engines and vehicles is both 
consistent with the agency's statutory mandate to determine how to 
implement a regulatory program designed to achieve the maximum feasible 
improvement and facilitates coordination with EPA's efforts to reduce 
greenhouse gas emissions. The Clean Air act, of course, mandates 
standards for both ``new motor vehicles'' and ``new motor vehicle 
engines'', so there is no issue of authority for separate engine 
standards under the EPA GHG program. CAA section 202(a)(1).
    As described elsewhere in this preamble, the final standards under 
the HD National Program address the complete vehicle, to the extent 
practicable and appropriate under the agencies' respective statutory 
authorities, through complementary engine and vehicle standards. The 
agencies continue to believe that this complementary engine and vehicle 
approach is the best way to achieve near term reductions from the 
heavy-duty sector. However, we also recognize as did the NAS committee 
and a wide range of industry and environmental commenters, that in 
order to fully capture the multi-faceted synergistic aspects of engine 
and vehicle design a more comprehensive complete vehicle standard may 
be appropriate in the future. The agencies are committed to fully 
exploring such a possibility and to developing the testing and modeling 
tools necessary to enable such a regulatory approach. We intend to work 
with all interested stakeholders as we move forward.
(1) Brief Overview of the Heavy-Duty Truck Industry
    The heavy-duty truck sector spans a wide range of vehicles with 
often unique form and function. A primary indicator of the extreme 
diversity among heavy-duty trucks is the range of load-carrying 
capability across the industry. The heavy-duty truck sector is often 
subdivided by vehicle weight classifications, as defined by the 
vehicle's gross vehicle weight rating (GVWR), which is a measure of the 
combined curb (empty) weight and cargo carrying capacity of the 
truck.\23\ Table I-2 below outlines the vehicle weight classifications 
commonly used for many years for a variety of purposes by businesses 
and by several federal agencies, including the Department of 
Transportation, the Environmental Protection Agency, the Department of 
Commerce, and the Internal Revenue Service.
---------------------------------------------------------------------------

    \23\ GVWR describes the maximum load that can be carried by a 
vehicle, including the weight of the vehicle itself. Heavy-duty 
vehicles also have a gross combined weight rating (GCWR), which 
describes the maximum load that the vehicle can haul, including the 
weight of a loaded trailer and the vehicle itself.

                                                        Table I-2--Vehicle Weight Classification
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Class                       2b               3                4                5                6                7                8
--------------------------------------------------------------------------------------------------------------------------------------------------------
GVWR (lb)........................     8,501-10,000    10,001-14,000    14,001-16,000    16,001-19,500    19,501-26,000    26,001-33,000         > 33,001
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In the framework of these vehicle weight classifications, the 
heavy-duty truck sector refers to Class 2b through Class 8 vehicles and 
the engines that power those vehicles.\24\ Unlike light-duty vehicles, 
which are primarily used for transporting passengers for personal 
travel, heavy-duty vehicles fill much more diverse operator needs. 
Heavy-duty pickup trucks and vans (Classes 2b and 3) are used chiefly 
as work truck and vans, and as shuttle vans, as well as for personal 
transportation, with an average annual mileage in the range of 15,000 
miles. The rest of the heavy-duty sector is used for carrying cargo 
and/or performing specialized tasks. ``Vocational'' vehicles, which may 
span Classes 2b through 8, vary widely in size, including smaller and 
larger van trucks, utility ``bucket'' trucks, tank

[[Page 57115]]

trucks, refuse trucks, urban and over-the-road buses, fire trucks, 
flat-bed trucks, and dump trucks, among others. The annual mileage of 
these trucks is as varied as their uses, but for the most part tends to 
fall in between heavy-duty pickups/vans and the large combination 
tractors, typically from 15,000 to 150,000 miles per year, although 
some travel more and some less. Class 7 and 8 combination tractor-
trailers--some equipped with sleeper cabs and some not--are primarily 
used for freight transportation. They are sold as tractors and 
sometimes run without a trailer in between loads, but most of the time 
they run with one or more trailers that can carry up to 50,000 pounds 
or more of payload, consuming significant quantities of fuel and 
producing significant amounts of GHG emissions. The combination 
tractor-trailers used in combination applications can travel more than 
150,000 miles per year.
---------------------------------------------------------------------------

    \24\ Class 2b vehicles designed as passenger vehicles (Medium 
Duty Passenger Vehicles, MDPVs) are covered by the light-duty GHG 
and fuel economy standards and not addressed in this rulemaking.
---------------------------------------------------------------------------

    EPA and NHTSA have designed our respective standards in careful 
consideration of the diversity and complexity of the heavy-duty truck 
industry, as discussed next.
(2) Summary of Final EPA GHG Emission Standards and NHTSA Fuel 
Consumption Standards
    As described above, NHTSA and EPA recognize the importance of 
addressing the entire vehicle in reducing fuel consumption and GHG 
emissions. At the same time, the agencies understand that the 
complexity of the industry means that we will need to use different 
approaches to achieve this goal, depending on the characteristics of 
each general type of truck. We are therefore dividing the industry into 
three discrete regulatory categories for purposes of setting our 
respective standards--combination tractors, heavy-duty pickups and 
vans, and vocational vehicles--based on the relative degree of 
homogeneity among trucks within each category. For each regulatory 
category, the agencies are adopting related but distinct program 
approaches reflecting the specific challenges that we see in these 
segments. In the following paragraphs, we discuss EPA's final GHG 
emission standards and NHTSA's final fuel consumption standards for the 
three regulatory categories of heavy-duty vehicles and their engines.
    The agencies are adopting test metrics that express fuel 
consumption and GHG emissions relative to the most important measures 
of heavy-duty truck utility for each segment, consistent with the 
recommendation of the 2010 NAS Report that metrics should reflect and 
account for the work performed by various types of HD vehicles. This 
approach differs from NHTSA's light-duty program that uses fuel economy 
as the basis. The NAS committee discussed the difference between fuel 
economy (a measure of how far a vehicle will go on a gallon of fuel) 
and fuel consumption (the inverse measure, of how much fuel is consumed 
in driving a given distance) as potential metrics for MD/HD 
regulations. The committee concluded that fuel economy would not be a 
good metric for judging the fuel efficiency of a heavy-duty vehicle, 
and stated that NHTSA should instead consider fuel consumption as the 
metric for its standards. As a result, for heavy-duty pickup trucks and 
vans, EPA and NHTSA are finalizing standards on a per-mile basis (g/
mile for the EPA standards, gallons/100 miles for the NHTSA standards), 
as explained in Section 0 below. For heavy-duty trucks, both 
combination and vocational, the agencies are adopting standards 
expressed in terms of the key measure of freight movement, tons of 
payload miles or, more simply, ton-miles. Hence, for EPA the final 
standards are in the form of the mass of emissions from carrying a ton 
of cargo over a distance of one mile (g/ton-mi). Similarly, the final 
NHTSA standards are in terms of gallons of fuel consumed over a set 
distance (one thousand miles), or gal/1,000 ton-mile. Finally, for 
engines, EPA is adopting standards in the form of grams of emissions 
per unit of work (g/bhp-hr), the same metric used for the heavy-duty 
highway engine standards for criteria pollutants today. Similarly, 
NHTSA is finalizing standards for heavy-duty engines in the form of 
gallons of fuel consumption per 100 units of work (gal/100 bhp-hr).
    Section II below discusses the final EPA and NHTSA standards in 
greater detail.
(a) Class 7 and 8 Combination Tractors
    Class 7 and 8 combination tractors and their engines contribute the 
largest portion of the total GHG emissions and fuel consumption of the 
heavy-duty sector, approximately 65 percent, due to their large 
payloads, their high annual miles traveled, and their major role in 
national freight transport.\25\ These vehicles consist of a cab and 
engine (tractor or combination tractor) and a detachable trailer. In 
general, reducing GHG emissions and fuel consumption for these vehicles 
will involve improvements in aerodynamics and tires and reduction in 
idle operation, as well as engine-based efficiency improvements.
---------------------------------------------------------------------------

    \25\ The on-highway Class 7 and 8 combination tractors 
constitute the vast majority of this regulatory category, and form 
the backbone of this HD National Program. A small fraction of 
combination tractors are used in off-road applications and are 
regulated differently, as described in Section II.
---------------------------------------------------------------------------

    In general, the heavy-duty combination tractor industry consists of 
tractor manufacturers (which manufacture the tractor and purchase and 
install the engine) and trailer manufacturers. These manufacturers are 
usually not the same entity. We are not aware of any manufacturer that 
typically assembles both the finished truck and the trailer and 
introduces the combination into commerce for sale to a buyer. The 
owners of trucks and trailers are often distinct as well. A typical 
truck buyer will purchase only the tractor. The trailers are usually 
purchased and owned by fleets and shippers. This occurs in part because 
trucking fleets on average maintain 3 trailers per tractor and in some 
cases as many as 6 or more trailers per tractor. There are also large 
differences in the kinds of manufacturers involved with producing 
tractors and trailers. For HD highway tractors and their engines, a 
relatively limited number of manufacturers produce the vast majority of 
these products. The trailer manufacturing industry is quite different, 
and includes a large number of companies, many of which are relatively 
small in size and production volume. Setting standards for the products 
involved--tractors and trailers--requires recognition of the large 
differences between these manufacturing industries, which can then 
warrant consideration of different regulatory approaches.
    Based on these industry characteristics, EPA and NHTSA believe that 
the most straightforward regulatory approach for combination tractors 
and trailers is to establish standards for tractors separately from 
trailers. As discussed below in Section IX, the agencies are adopting 
standards for the tractors and their engines in this rulemaking, but 
did not propose and are not adopting standards for trailers.
    As with the other regulatory categories of heavy-duty vehicles, EPA 
and NHTSA have concluded that achieving reductions in GHG emissions and 
fuel consumption from combination tractors requires addressing both the 
cab and the engine, and EPA and NHTSA each are adopting standards that 
reflect this conclusion. The importance of the cab is that its design 
determines the amount of power that the engine must produce in moving 
the truck down the road. As illustrated in Figure I-1, the loads that 
require additional power from the engine include air resistance 
(aerodynamics), tire rolling resistance,

[[Page 57116]]

and parasitic losses (including accessory loads and friction in the 
drivetrain). The importance of the engine design is that it determines 
the basic GHG emissions and fuel consumption performance of the engine 
for the variety of demands placed on the engine, regardless of the 
characteristics of the cab in which it is installed. The agencies 
intend for the final standards to result in the application of improved 
technologies for lower GHG emissions and fuel consumption for both the 
cab and the engine.
---------------------------------------------------------------------------

    \26\ Adapted from Figure 4.1. Class 8 Truck Energy Audit, 
Technology Roadmap for the 21st Century Truck Program: A Government-
Industry Research Partnership, 21CT-001, December 2000.
[GRAPHIC] [TIFF OMITTED] TR15SE11.000

    Accordingly, for Class 7 and 8 combination tractors, the agencies 
are each finalizing two sets of standards. For vehicle-related 
emissions and fuel consumption, tractor manufacturers are required to 
meet vehicle-based standards. Compliance with the vehicle standard will 
typically be determined based on a customized vehicle simulation model, 
called the Greenhouse gas Emissions Model (GEM), which is consistent 
with the NAS Report recommendations to require compliance testing for 
combination tractors using vehicle simulation rather than chassis 
dynamometer testing. This compliance model was developed by EPA 
specifically for this final action. It is an accurate and cost-
effective alternative to measuring emissions and fuel consumption while 
operating the vehicle on a chassis dynamometer. Instead of using a 
chassis dynamometer as an indirect way to evaluate real-world operation 
and performance, various characteristics of the vehicle are measured 
and these measurements are used as inputs to the model. These 
characteristics relate to key technologies appropriate for this 
subcategory of truck--including aerodynamic features, weight 
reductions, tire rolling resistance, the presence of idle-reducing 
technology, and vehicle speed limiters. The model also assumes the use 
of a representative typical engine, rather than a vehicle-specific 
engine, because engines are regulated separately. Using these inputs, 
the model will be used to quantify the overall performance of the 
vehicle in terms of CO2 emissions and fuel consumption. The 
model's development and design, as well as the sources for inputs, are 
discussed in detail in Section II below and in Chapter 4 of the RIA.
(i) Final Standards for Class 7 and 8 Combination Tractors and Their 
Engines
    The vehicle standards that EPA and NHTSA are adopting for Class 7 
and 8 combination tractor manufacturers are based on several key 
attributes related to GHG emissions and fuel consumption that we 
believe reasonably represent the many differences in utility and 
performance among these vehicles. The final standards differ depending 
on GVWR (i.e., whether the truck is Class 7 or Class 8), the height of 
the roof of the cab, and whether it is a ``day cab'' or a ``sleeper 
cab.'' These later two attributes are important because the height of 
the roof, designed to correspond to the height of the trailer, 
significantly affects air resistance, and a sleeper cab generally 
corresponds to the opportunity for extended duration idle emission and 
fuel consumption improvements. We received a number of comments 
supporting this approach and no comments that provided a compelling 
reason to change our approach in this final action.
    Thus, the agencies have created nine subcategories within the Class 
7 and 8 combination tractor category based on the differences in 
expected emissions and fuel consumption associated with the key 
attributes of GVWR, cab type, and roof height. The agencies are setting 
standards beginning in 2014 model year with more stringent standards 
following in 2017 model year. Table I-3 presents the agencies' 
respective standards for combination tractor manufacturers for the 2017 
model year. The standards represent an overall fuel consumption and 
CO2 emissions reduction up to 23 percent from the tractors 
and the engines installed in them when compared to a baseline 2010 
model year tractor and engine without idle shutdown technology. The 
standard values shown below differ somewhat from the proposal, 
reflecting refinements made to the GEM in response to comments. These 
changes did not impact our estimates of the relative effectiveness of 
the various control technologies modeled in this final action nor the 
overall cost or benefits or cost effectiveness estimated for these 
final vehicle standards.
    As proposed, the agencies are exempting certain types of tractors 
which operate off-road to be exempt

[[Page 57117]]

from the combination tractor vehicle standards (although standards 
would still apply to the engines installed in these vehicles). The 
criteria for tractors to be considered off-road have been amended 
slightly from those proposed, in response to public comment. The 
agencies have also recognized, again in response to public comment, 
that some combination tractors operate in a manner essentially the same 
as vocational vehicles and have created a subcategory of ``vocational 
tractors'' as a result. Vocational tractors will be subject to the 
standards for vocational vehicles rather than the combination tractor 
standards. See Section II.B of this preamble.

  Table I-3--Heavy-Duty Combination Tractor EPA Emissions Standards (G CO2/Ton-Mile) and NHTSA Fuel Consumption
                                         Standards (GAL/1,000 Ton-Mile)
----------------------------------------------------------------------------------------------------------------
                                                                        Day cab                   Sleeper cab
                                                        --------------------------------------------------------
                                                              Class 7            Class 8            Class 8
----------------------------------------------------------------------------------------------------------------
                                     2017 Model Year CO2 Grams per Ton-Mile
----------------------------------------------------------------------------------------------------------------
Low Roof...............................................              104                 80                 66
Mid Roof...............................................              115                 86                 73
High Roof..............................................              120                 89                 72
----------------------------------------------------------------------------------------------------------------
                               2017 Model Year Gallons of Fuel per 1,000 Ton-Mile
----------------------------------------------------------------------------------------------------------------
Low Roof...............................................               10.2                7.8                6.5
Mid Roof...............................................               11.3                8.4                7.2
High Roof..............................................               11.8                8.7                7.1
----------------------------------------------------------------------------------------------------------------

    In addition, the agencies are finalizing separate performance 
standards for the engines manufactured for use in these trucks. EPA's 
engine-based CO2 standards and NHTSA's engine-based fuel 
consumption standards are implemented using EPA's existing test 
procedures and regulatory structure for criteria pollutant emissions 
from medium- and heavy-duty engines. As at proposal, the final engine 
standards vary depending on engine size linked to intended vehicle 
service class. Consistent with our proposal, the agencies are 
finalizing an interim alternative compression ignition engine standard 
for model years 2014-2016. This alternative standard is designed to 
provide a glide path for legacy diesel engine products that may not be 
able to comply with the final engine standards for model years 2014-16 
given the short (approximately 2-year) lead time of this program. We 
believe this alternative standard is appropriate for a first-ever 
program when the overall baseline performance of the industry is quite 
varied and where the short lead time means that not every product can 
be brought into compliance by 2014. The alternative standard only 
applies through and including model year 2016.
    Separately, EPA is adopting standards for combination tractors that 
apply in use. EPA is also finalizing engine-based N2O and 
CH4 standards for manufacturers of the engines used in these 
combination tractors. EPA is finalizing separate engine-based standards 
for N2O and CH4 because the agency believes that 
emissions of these GHGs are technologically related solely to the 
engine, fuel, and emissions aftertreatment systems, and the agency is 
not aware of any influence of vehicle-based technologies on these 
emissions. NHTSA is not incorporating standards for N2O and 
CH4 because these emissions do not impact fuel consumption 
in a significant way. The standards that EPA is finalizing for 
N2O and CH4 are less stringent than those we 
proposed, reflecting new data provided to EPA in comments on the 
proposal showing that the current baseline level of N2O and 
CH4 emissions varies more than EPA had expected. EPA expects 
that manufacturers of current engine technologies will be able to 
comply with the final N2O and CH4 ``cap'' 
standards with little or no technological improvements; the value of 
the standards will be to prevent significant increases in these 
emissions as alternative technologies are developed and introduced in 
the future. Compliance with the final EPA engine-based CO2 
standards and the final NHTSA engine-based fuel consumption standards, 
as well as the final EPA N2O and CH4 standards, 
will be determined using the appropriate EPA engine test procedure, as 
discussed in Sections II.B, II.D, and II.E below.
    As with the other categories of heavy-duty vehicles, EPA and NHTSA 
are finalizing respective standards that will apply to Class 7 and 8 
tractors at the time of production (as in Table I-3, above). In 
addition, EPA is finalizing separate standards that will apply for a 
specified period of time in use. All of the standards for these 
vehicles, as well as details about the provisions for certification and 
implementation of these standards, are discussed in more detail in 
Sections II, III, IV, and V below and in the RIA.
(ii) EPA's Final Air Conditioning Leakage Standard for Class 7 and 8 
Combination Tractors
    In addition to the final EPA tractor- and engine-based standards 
for CO2 and engine-based standards for N2O, and 
CH4 emissions, EPA is finalizing a separate standard to 
reduce leakage of HFC refrigerant from cabin air conditioning (A/C) 
systems from combination tractors, to apply to the tractor 
manufacturer. This standard is independent of the CO2 
tractor standard, as discussed below in Section II.E.5. Because the 
current refrigerant used widely in all these systems has a very high 
global warming potential, EPA is concerned about leakage of 
refrigerant.\27\
---------------------------------------------------------------------------

    \27\ The global warming potential for HFC-134a refrigerant of 
1430 used in this program is consistent with the Intergovernmental 
Panel on Climate Change Fourth Assessment Report.
---------------------------------------------------------------------------

    Because the interior volume to be cooled for most tractor cabins is 
similar to that of light-duty vehicles, the size and design of current 
tractor A/C systems is also very similar. The compliance approach for 
Class 7 and 8 tractors is therefore similar to that in the light-duty 
rule in that these standards are design-based. Manufacturers will 
choose technologies from a menu of leak-reducing technologies 
sufficient to comply with the standard, as opposed to using a test to 
measure performance.
    However, the final heavy-duty A/C provisions differ in two 
important ways from those established in the light-duty rule. First, 
the light-duty provisions were established as voluntary ways to

[[Page 57118]]

generate credits towards the CO2 g/mi standard, and EPA took 
into account the expected use of such credits in determining the 
stringency of the CO2 emissions standards. In the HD 
National Program, EPA is requiring that manufacturers actually meet a 
standard--as opposed to having the opportunity to earn a credit--for A/
C refrigerant leakage. Thus, refrigerant leakage control is not 
separately accounted for in the final heavy-duty CO2 
standards. We are taking this approach here recognizing that while the 
benefits of leakage control are almost identical between light-duty and 
heavy-duty vehicles on a per vehicle basis, these benefits on a per 
mile basis expressed as a percentage of overall GHG emissions are much 
smaller for heavy-duty vehicles due to their much higher CO2 
emissions rates and higher annual mileage when compared to light-duty 
vehicles. Hence a credit-based approach as done for light-duty vehicles 
would provide less motivation for manufacturers to install low leakage 
systems even though such systems represent a highly cost effective 
means to control GHG emissions. The second difference relates to the 
expression of the leakage rate. The light-duty A/C leakage standard is 
expressed in terms of grams per year. For EPA's heavy-duty program, 
however, because of the wide variety of system designs and 
arrangements, a one-size-fits-all gram per year standard would not be 
appropriate, so EPA is adopting a standard in terms of annual mass 
leakage rate for A/C systems with refrigerant capacities less than or 
equal to 733 grams and percent of total refrigerant leakage per year 
for A/C systems with refrigerant capacities greater than 733 grams. The 
percent of total refrigerant leakage per year requires the total 
refrigerant capacity of the A/C system to be taken into account in 
determining compliance. EPA believes that this approach--a standard 
instead of a credit, and basing the standard on percent or mass of 
leakage over time--is more appropriate for heavy-duty tractors than the 
light-duty vehicle approach and that it will achieve the desired 
reductions in refrigerant leakage. Compliance with the standard will be 
determined through a showing by the tractor manufacturer that its A/C 
system incorporates a combination of low-leak technologies sufficient 
to meet the leakage rate of the applicable standard. The ``menu'' of 
technologies is very similar to that established in the light-duty 
2012-2016 MY vehicle rule.\28\
---------------------------------------------------------------------------

    \28\ EPA has approved an alternative refrigerant, HFO-1234yf, 
which has a very low GWP, for use in light-duty vehicle mobile A/C 
systems. The final heavy-duty vehicle A/C leakage standard is 
designed to account for use of an alternative, low-GWP refrigerant. 
If in the future this refrigerant is approved for heavy-duty 
applications and if it becomes widespread as a substitute for HFC-
134a in heavy-duty vehicle mobile A/C systems, EPA may propose to 
revise or eliminate the leakage standard.
---------------------------------------------------------------------------

    Finally, the agencies did not propose and are not adopting an A/C 
system efficiency standard in this heavy-duty rulemaking, although an 
efficiency credit was a part of the light-duty rule. The much larger 
emissions of CO2 from a heavy-duty tractor as compared to 
those from a light-duty vehicle mean that the relative amount of 
CO2 that could be reduced through A/C efficiency 
improvements is very small.
    A more detailed discussion of A/C related issues is found in 
Section II.E.5 of this preamble.
(b) Heavy-Duty Pickup Trucks and Vans (Class 2b and 3)
    Heavy-duty vehicles with GVWR between 8,501 and 10,000 lb are 
classified in the industry as Class 2b motor vehicles per the Federal 
Motor Carrier Safety Administration definition. As discussed above, 
Class 2b includes MDPVs that are regulated by the agencies under the 
light-duty vehicle rule, and the agencies are not adopting additional 
requirements for MDPVs in this rulemaking. Heavy-duty vehicles with 
GVWR between 10,001 and 14,000 lb are classified as Class 3 motor 
vehicles. Class 2b and Class 3 heavy-duty vehicles (referred to in 
these rules as ``HD pickups and vans'') together emit about 15 percent 
of today's GHG emissions from the heavy-duty vehicle sector.
    About 90 percent of HD pickups and vans are \3/4\-ton and 1-ton 
pickup trucks, 12- and 15-passenger vans, and large work vans that are 
sold by vehicle manufacturers as complete vehicles, with no secondary 
manufacturer making substantial modifications prior to registration and 
use. These vehicle manufacturers are companies with major light-duty 
markets in the United States, primarily Ford, General Motors, and 
Chrysler. Furthermore, the technologies available to reduce fuel 
consumption and GHG emissions from this segment are similar to the 
technologies used on light-duty pickup trucks, including both engine 
efficiency improvements (for gasoline and diesel engines) and vehicle 
efficiency improvements.
    For these reasons, EPA believes it is appropriate to adopt GHG 
standards for HD pickups and vans based on the whole vehicle (including 
the engine), expressed as grams per mile, consistent with the way these 
vehicles are regulated by EPA today for criteria pollutants. NHTSA 
believes it is appropriate to adopt corresponding gallons per 100 mile 
fuel consumption standards that are likewise based on the whole 
vehicle. This complete vehicle approach being adopted by both agencies 
for HD pickups and vans is consistent with the recommendations of the 
NAS Committee in their 2010 Report. EPA and NHTSA also believe that the 
structure and many of the detailed provisions of the recently finalized 
light-duty GHG and fuel economy program, which also involves vehicle-
based standards, are appropriate for the HD pickup and van GHG and fuel 
consumption standards as well, and this is reflected in the standards 
each agency is finalizing, as detailed in Section II.C. These 
commonalities include a new vehicle fleet average standard for each 
manufacturer in each model year and the determination of these fleet 
average standards based on production volume-weighted targets for each 
model, with the targets varying based on a defined vehicle attribute. 
Vehicle testing will be conducted on chassis dynamometers using the 
drive cycles from the EPA Federal Test Procedure (Light-duty FTP or 
``city'' test) and Highway Fuel Economy Test (HFET or ``highway'' 
test).\29\
---------------------------------------------------------------------------

    \29\ The Light-duty FTP is a vehicle driving cycle that was 
originally developed for certifying light-duty vehicles and 
subsequently applied to HD chassis testing for criteria pollutants. 
This contrasts with the Heavy-duty FTP, which refers to the 
transient engine test cycles used for certifying heavy-duty engines 
(with separate cycles specified for diesel and spark-ignition 
engines).
---------------------------------------------------------------------------

    For the light-duty GHG and fuel economy standards, the agencies 
factored in vehicle size by basing the emissions and fuel economy 
targets on vehicle footprint (the wheelbase times the average track 
width).\30\ For those standards, passenger cars and light trucks with 
larger footprints are assigned higher GHG and lower fuel economy target 
levels in acknowledgement of their inherent tendency to consume more 
fuel and emit more GHGs per mile. For HD pickups and vans, the agencies 
believe that setting standards based on vehicle attributes is 
appropriate, but feel that a work-based metric serves as a better 
attribute than the footprint attribute utilized in the light-duty 
vehicle

[[Page 57119]]

rulemaking. Work-based measures such as payload and towing capability 
are key among the parameters that characterize differences in the 
design of these vehicles, as well as differences in how the vehicles 
will be utilized. Buyers consider these utility-based attributes when 
purchasing a heavy-duty pickup or van. EPA and NHTSA are therefore 
finalizing standards for HD pickups and vans based on a ``work factor'' 
attribute that combines their payload and towing capabilities, with an 
added adjustment for 4-wheel drive vehicles. The agencies received a 
number of comments supporting this approach arguing, as the agencies 
had, that this approach was an effective way to encourage technology 
development and to appropriately reflect the utility of work vehicles 
while setting a consistent metric measure of vehicle performance.
---------------------------------------------------------------------------

    \30\ EISA requires CAFE standards for passenger cars and light 
trucks to be attribute-based; See 49 U.S.C. 32902(b)(3)(A).
---------------------------------------------------------------------------

    As proposed, the agencies are adopting provisions such that each 
manufacturer's fleet average standard will be based on production 
volume-weighting of target standards for all vehicles that in turn are 
based on each vehicle's work factor. These target standards are taken 
from a set of curves (mathematical functions), presented in Section 
II.C below and in Sec.  1037.104. EPA is also phasing in the 
CO2 standards gradually starting in the 2014 model year, at 
15-20-40-60-100 percent of the model year 2018 standards stringency 
level in model years 2014-2015-2016-2017-2018, respectively. The phase-
in takes the form of a set of target standard curves, with increasing 
stringency in each model year, as detailed in Section II.C. The final 
EPA standards for 2018 (including a separate standard to control air 
conditioning system leakage) represent an average per-vehicle reduction 
in GHGs of 17 percent for diesel vehicles and 12 percent for gasoline 
vehicles, compared to a common baseline, as described in Sections II.C 
and III.B of this preamble. The rule contains separate standards for 
diesel and gasoline heavy duty pickups and vans for reasons described 
in Section II.C below. EPA is also finalizing a compliance alternative 
whereby manufacturers can phase in different percentages: 15-20-67-67-
67-100 percent of the model year 2019 standards stringency level in 
model years 2014-2015-2016-2017-2018-2019, respectively. This 
compliance alternative parallels and is equivalent to NHTSA's first 
alternative described below.
    NHTSA is allowing manufacturers to select one of two fuel 
consumption standard alternatives for model years 2016 and later. The 
first alternative defines individual gasoline vehicle and diesel 
vehicle fuel consumption target curves that will not change for model 
years 2016-2018, and are equivalent to EPA's 67-67-67-100 percent 
target curves in model years 2016-2017-2018-2019, respectively. The 
target curves for this alternative are presented in Section II.C. The 
second alternative uses target curves that are equivalent to the EPA's 
40-60-100 percent target curves in model years 2016-2017-2018, 
respectively. Stringency for the alternatives has been selected to 
allow a manufacturer, through the use of the credit and deficit carry-
forward provisions that the agencies are also finalizing, to rely on 
the same product plans to satisfy either of these two alternatives, and 
also EPA requirements. If a manufacturer cannot meet an applicable 
standard in a given model year, it may make up its shortfall by 
overcomplying in a subsequent year, called reconciling a credit 
deficit. NHTSA is also allowing manufacturers to voluntarily opt into 
the NHTSA HD pickup and van program in model years 2014 or 2015. For 
these model years, NHTSA's fuel consumption target curves are 
equivalent to EPA's target curves.
    The agencies received a number of comments including from the 
Senate authors and supporters of the Ten-in-Ten Fuel Economy Act 
suggesting that the standards for heavy-duty pickups and vans should be 
made more stringent for gasoline vehicles and that the phase-in timing 
of the standards should be accelerated to the 2016 model year (from 
2018). We also received comments arguing that the proposed standards 
were aggressive and could only be met given the phase-in schedules 
proposed by the agencies. In response to these comments, we reviewed 
again the technology assessments from the 2010 NAS report, our own 
joint light-duty 2012-2016 rulemaking, and information provided by the 
commenters relevant to the stringency of these standards. After 
reviewing all of the information, we continue to conclude that the 
proposed standards and associated phase-in schedules represent 
technically stringent but reasonable standards considering the 
available lead time and costs to bring the necessary technologies to 
market and our own assessments of the efficacy of the technologies when 
applied to heavy-duty pickup trucks and vans. Further detail on the 
feasibility of the standards and the agencies' choices among 
alternative standards is found in Section III.C below.
    The Senate authors and supporters of the Ten-in-Ten Fuel Economy 
Act sent a letter to the agencies encouraging the agencies to finalize 
a fuel economy labeling requirement for heavy-duty pickups and 
vans.\31\ The agencies recognize that consumer information in the form 
of a fuel efficiency label can be a valuable tool to help achieve our 
goals, and we note that the agencies have just recently finalized a new 
fuel economy label for passenger cars and light trucks. See 76 FR at 
39478. That rulemaking effort focused solely on modifying an existing 
label and was a multi-year process with significant public input. As we 
did not propose a consumer label for heavy-duty pickups and vans in 
this action and have not appropriately engaged the public in developing 
such a label, we are not prepared to finalize a consumer-based label in 
this action. However, we do intend to consider this issue as we begin 
work on the next phase of regulations, as we recognize that a consumer 
label can play an important role in reducing fuel consumption and GHG 
emissions.
---------------------------------------------------------------------------

    \31\ See Docket EPA-HQ-OAR-2010-0162.
---------------------------------------------------------------------------

    The form and stringency of the EPA and NHTSA standards curves are 
based on a set of vehicle, engine, and transmission technologies 
expected to be used to meet the recently established GHG emissions and 
fuel economy standards for model year 2012-2016 light-duty vehicles, 
with full consideration of how these technologies are likely to perform 
in heavy-duty vehicle testing and use. All of these technologies are 
already in use or have been announced for upcoming model years in some 
light-duty vehicle models, and some are in use in a portion of HD 
pickups and vans as well. The technologies include:
     Advanced 8-speed automatic transmissions.
     Aerodynamic improvements.
     Electro-hydraulic power steering.
     Engine friction reductions.
     Improved accessories.
     Low friction lubricants in powertrain components.
     Lower rolling resistance tires.
     Lightweighting.
     Gasoline direct injection.
     Diesel aftertreatment optimization.
     Air conditioning system leakage reduction (for EPA program 
only).
    See Section III.B for a detailed analysis of these and other 
potential technologies, including their feasibility, costs, and 
effectiveness when employed for reducing fuel consumption and 
CO2 emissions in HD pickups and vans.
    A relatively small number of HD pickups and vans are sold by 
vehicle manufacturers as incomplete vehicles, without the primary load-
carrying

[[Page 57120]]

device or container attached. We are generally regulating these 
vehicles as Class 2b through 8 vocational vehicles but are also 
allowing manufacturers the option to choose to comply with heavy-duty 
pickup or van standards, as described in Section I.C.(2)(c). Although, 
as with vocational vehicles generally, we have little information on 
baseline aerodynamic performance and opportunities for improvement, a 
sizeable subset of these incomplete vehicles, often called cab-chassis 
vehicles, are sold by the vehicle manufacturers in configurations with 
many of the components that affect GHG emissions and fuel consumption 
identical to those on complete pickup truck or van counterparts--
including engines, cabs, frames, transmissions, axles, and wheels. We 
are including provisions that will allow manufacturers to include these 
vehicles, as well as some Class 4 and 5 vehicles, to be regulated under 
the chassis-based HD pickup and van program (i.e. subject to the 
standards for HD pickups and vans), rather than the vocational vehicle 
program. These provisions are described in Section V.B(1)(e).
    In addition to the EPA CO2 emission standards and the 
NHTSA fuel consumption standards for HD pickups and vans, EPA is also 
finalizing standards for two additional GHGs, N2O and 
CH4, as well as standards for air conditioning-related HFC 
emissions. These standards are discussed in more detail in Section 
II.E. Finally, EPA is finalizing standards that will apply to HD 
pickups and vans in use. All of the standards for these HD pickups and 
vans, as well as details about the provisions for certification and 
implementation of these standards, are discussed in Section II.C.
(c) Class 2b-8 Vocational Vehicles
    Class 2b-8 vocational vehicles consist of a wide variety of vehicle 
types. Some of the primary applications for vehicles in this segment 
include delivery, refuse, utility, dump, and cement trucks; transit, 
shuttle, and school buses; emergency vehicles, motor homes,\32\ tow 
trucks, among others. These vehicles and their engines contribute 
approximately 20 percent of today's heavy-duty truck sector GHG 
emissions.
---------------------------------------------------------------------------

    \32\ NHTSA's final fuel consumption standards will not apply to 
recreational vehicles, as discussed in earlier in this preamble 
section.
---------------------------------------------------------------------------

    Manufacturing of vehicles in this segment of the industry is 
organized in a more complex way than that of the other heavy-duty 
categories. Class 2b-8 vocational vehicles are often built as a chassis 
with an installed engine and an installed transmission. Both the engine 
and transmissions are typically manufactured by other manufacturers and 
the chassis manufacturer purchases and installs them. Many of the same 
companies that build Class 7 and 8 tractors are also in the Class 2b-8 
chassis manufacturing market. The chassis is typically then sent to a 
body manufacturer, which completes the vehicle by installing the 
appropriate feature--such as dump bed, delivery box, or utility 
bucket--onto the chassis. Vehicle body manufacturers tend to be small 
businesses that specialize in specific types of bodies or specialized 
features.
    EPA and NHTSA proposed that in this vocational vehicle category the 
proposed GHG and fuel consumption standards apply to chassis 
manufacturers. Chassis manufacturers play a central role in the 
manufacturing process. The product they produce--the chassis with 
engine and transmission--includes the primary technologies that affect 
GHG emissions and fuel consumption. They also constitute a much more 
limited group of manufacturers for purposes of developing and 
implementing a regulatory program. The agencies believe that a focus on 
the body manufacturers would be much less practical, since they 
represent a much more diverse set of manufacturers, many of whom are 
small businesses. Further, the part of the vehicle that they add 
affords very few opportunities to reduce GHG emissions and fuel 
consumption (given the limited role that aerodynamics plays in many 
types of lower speed and stop-and-go operation typically found with 
vocational vehicles.) Therefore, the agencies proposed that the 
standards in this vocational vehicle category would apply to the 
chassis manufacturers of all heavy-duty vehicles not otherwise covered 
by the HD pickup and van standards or Class 7 and 8 combination tractor 
standards discussed above. The agencies requested comment on the 
proposed focus on chassis manufacturers.
    Volvo and Daimler commented that the EISA does not speak to the 
regulation of subsystems, such as engines or incomplete vehicles, and 
argued that on the other hand, Section 32902(k)(2) prescribes the 
regulation of vehicles. Volvo further stated that precedent for the 
regulation of complete vehicles exists in the light-duty fuel economy 
rule. As noted above, NHTSA does not believe that EISA mandates a 
particular regulatory approach, but rather gives the agency wide 
latitude and explicitly leaves that determination to the agency. NHTSA 
also notes that its heavy-duty rule creates a new fuel efficiency 
program for which the light-duty program does not necessarily serve as 
a useful precedent for considerations of its structure. Unlike the 
light-duty fuel economy program, MD/HD vehicles are produced in widely 
diverse stages. Further, given the MD/HD market structure, where the 
complete vehicle manufacturers are numerous, diverse, and often small 
businesses, the regulation of complete vehicles would create unique 
difficulties for the application of appropriate and feasible 
technologies. These same considerations justify EPA's determination, 
pursuant to CAA section 202 (a), to regulate only chassis manufacturers 
in this first stage of GHG rules for the heavy-duty sector. NHTSA also 
notes that this rule does not represent the first time that the agency 
has regulated incomplete vehicles. Rather, incomplete vehicles have a 
history of regulation under the Federal Motor Vehicle Safety 
Standards.\33\ For this first phase of the HD National Program, NHTSA 
and EPA believe that given the complexity of the manufacturing process 
for vocational vehicles, and given the wide range of entities that 
participate in that process, vehicle fuel consumption standards would 
be most appropriately applied to chassis manufacturers and not to body 
builders.
---------------------------------------------------------------------------

    \33\ See 49 U.S.C. 567.5 and 568.4.
---------------------------------------------------------------------------

    The agencies continue to believe that regulation of the chassis 
manufacturers for this vocational vehicle category will achieve the 
maximum feasible improvement in fuel efficiency for purposes of EISA 
and appropriate emissions reductions for purposes of the CAA. 
Therefore, consistent with our proposal the final standards in this 
vocational vehicle category apply to the chassis manufacturers of all 
heavy-duty vehicles not otherwise covered by the HD pickup and van 
standards or Class 7 and 8 combination tractor standards discussed 
above. As discussed above, EPA and NHTSA have concluded that reductions 
in GHG emissions and fuel consumption require addressing both the 
vehicle and the engine. As discussed above for Class 7 and 8 
combination tractors, the agencies are each finalizing two sets of 
standards for Class 2b-8 vocational vehicles. For vehicle-related 
emissions and fuel consumption, the agencies are adopting standards for 
chassis manufacturers: EPA CO2 (g/ton-mile) standards and 
NHTSA fuel consumption (gal/1,000 ton-mile) standards). While the 
agencies believe that a freight-based metric is broadly appropriate for 
vocational vehicles

[[Page 57121]]

because the vocational vehicle population is dominated by freight 
trucks and maintain that it is appropriate for the first phase of the 
program, the agencies may consider other metrics for future phases of a 
HD program. Manufacturers will use GEM, the same customized vehicle 
simulation model used for Class 7 and 8 tractors, to determine 
compliance with the vocational vehicle standards finalized in this 
action. The primary manufacturer-generated input into the GEM for this 
category of trucks will be a measure of tire rolling resistance, as 
discussed further below, because tire improvements are the primary 
means of vehicle improvement available at this time for vocational 
vehicles. The model also assumes the use of a typical representative, 
compliant engine in the simulation, resulting in an overall value for 
CO2 emissions and one for fuel consumption. This is done for 
the same reason as for combination tractors. As is the case for 
combination tractors, the manufacturers of the engines intended for 
vocational vehicles will be subject to separate engine-based standards.
(i) Final Standards for Class 2b-8 Vocational Vehicles and Their 
Engines
    Based on our analysis and research, the agencies believe that the 
primary opportunity for reductions in vocational vehicle GHG emissions 
and fuel consumption will be through improved engine technologies and 
improved tire rolling resistance. For engines, EPA and NHTSA are 
adopting separate standards for the manufacturers of engines used in 
Class 2b-8 vocational vehicles (the same approach as for combination 
tractors and engines intended for use in those tractors). EPA's final 
engine-based CO2 standards and NHTSA's final engine-based 
fuel consumption standards vary based on the expected weight class and 
usage of the truck into which the engine will be installed. Tire 
rolling resistance is closely related to the weight of the vehicle. 
Therefore, we are adopting vehicle-based standards for these trucks 
which vary according to one key attribute, GVWR. For this initial HD 
rulemaking, we are adopting standards based on the same groupings of 
truck weight classes used for the engine standards--light heavy-duty, 
medium heavy-duty, and heavy heavy-duty. These groupings are 
appropriate for the final vehicle-based standards because they parallel 
the general divisions among key engine characteristics, as discussed in 
Section II.
    The agencies are also finalizing an interim alternative compression 
ignition (diesel) engine standard for model years 2014-2016, again 
analogous to the alternative standards for compression ignition engines 
use in combination tractors. The need for this provision and our 
considerations in adopting it are the same for the engines used in 
vocational vehicles as for the engines used in combination tractors. As 
we proposed, these alternative standards will only be available through 
model year 2016. In addition, manufacturers that use the interim 
alternative diesel engine standards for model years 2014-2016 under the 
EPA program must use equivalent fuel consumption standards under the 
NHTSA program.
    For the 2014 to 2016 model years, manufacturers may also choose to 
meet alternative engine standards that are phased-in over the model 
years to coincide with new EPA On-Board Diagnostic (OBD) requirements 
applicable for these same model years. See Sections II.B and II.D 
below.
    The agencies received a significant number of comments including 
from the Senate authors and supporters of the Ten-in-Ten Fuel Economy 
Act arguing that our proposed standards for vocational vehicles did not 
reflect all of the technologies identified in the 2010 NAS report. The 
commenters encouraged the agencies to expand the program to bring in 
additional reductions through the use of new transmission technologies, 
vehicle weight reductions and hybrid drivetrains. In general, the 
agencies agree with the commenters' central contention that there are 
additional technologies to improve the fuel efficiency of vocational 
vehicles. As discussed later, we are finalizing provisions to allow new 
technologies to be brought into the program through the innovative 
technology credit program. More specifically, we are including 
provisions to account for and credit the use of hybrid technology as a 
technology that can reduce emissions and fuel consumption. Hybrid 
technology can currently be a cost-effective technology in certain 
specific vocational applications, and the agencies want to recognize 
and promote the use of this technology. (See Sections I.E and IV 
below.) However, we are not finalizing standards that are premised on 
the use of these additional technologies because we have not been able 
to develop the test procedures, regulatory mechanisms and baseline 
performance data necessary to adopt a more comprehensive approach to 
controlling fuel efficiency and GHG emissions from vocational vehicles. 
In concept, the agencies would need to know the baseline weight, 
aerodynamic performance, and transmission configuration for the wide 
range of vocational vehicles produced today. We do not have this 
information even for relatively small portions of this market (e.g. 
concrete mixers) nor are we well informed regarding the potential 
tradeoffs to changes to vehicle utility that might exist for changes to 
concrete mixer designs in response to a regulation. Nor did the 
commenters provide any such information. Absent this information and 
the necessary regulatory tools, we believe the standards we are 
finalizing for vocational vehicles represent the most appropriate 
standards for this segment during the model years of the first phase of 
the program. We intend to address fuel consumption and GHG emissions 
from these vehicles in a more comprehensive manner through future 
regulation and look forward to working with all stakeholders on this 
important segment in the future.
    The agencies are setting standards beginning in the 2014 model year 
and establishing more stringent standards in the 2017 model year. Table 
I-4 presents EPA's final CO2 standards and NHTSA's final 
fuel consumption standards for chassis manufacturers of Class 2b 
through Class 8 vocational vehicles for the 2017 model year. The 2017 
model year standards represent a 6 to 9 percent reduction in 
CO2 emissions and fuel consumption over a 2010 model year 
vehicle.

   Table I-4--Final 2017 Class 2b-8 Vocational Vehicle EPA CO2 Standards and NHTSA Fuel Consumption Standards
----------------------------------------------------------------------------------------------------------------
                                                          Light heavy-duty  Medium heavy-duty   Heavy heavy-duty
                                                             Class 2b-5         Class 6-7           Class 8
----------------------------------------------------------------------------------------------------------------
                           EPA CO2 (gram/ton-mile) Standard Effective 2017 Model Year
----------------------------------------------------------------------------------------------------------------
CO2 Emissions..........................................              373                225                222
----------------------------------------------------------------------------------------------------------------

[[Page 57122]]

 
              NHTSA Fuel Consumption (gallon per 1,000 ton-mile) Standard Effective 2017 Model Year
----------------------------------------------------------------------------------------------------------------
Fuel Consumption.......................................               36.7               22.1               21.8
----------------------------------------------------------------------------------------------------------------

     As mentioned above for Class 7 and 8 combination tractors, EPA 
believes that N2O and CH4 emissions are 
technologically related solely to the engine, fuel, and emissions 
aftertreatment systems, and the agency is not aware of any influence of 
vehicle-based technologies on these emissions. Therefore, for Class 2b-
8 vocational vehicles, EPA's final N2O and CH4 
standards cover manufacturers of the engines to be used in vocational 
vehicles. EPA did not propose, nor are we adopting separate vehicle-
based standards for these GHGs. As for the engines used in Class 7 and 
8 tractors, we are finalizing a somewhat higher N2O and 
CH4 emission standards reflecting new data submitted to the 
agencies during the public comment period. EPA expects that 
manufacturers of current engine technologies will be able to comply 
with the final ``cap'' standards with little or no technological 
improvements; the value of the standards is that they will prevent 
significant increases in these emissions as alternative technologies 
are developed and introduced in the future. Compliance with the final 
EPA engine-based CO2 standards and the final NHTSA fuel 
consumption standards, as well as the final EPA N2O and 
CH4 standards, will be determined using the appropriate EPA 
engine test procedure, as discussed in Section II below.
    As with the other regulatory categories of heavy-duty vehicles, EPA 
and NHTSA are adopting standards that apply to Class 2b-8 vocational 
vehicles at the time of production, and EPA is adopting standards for a 
specified period of time in use. All of the standards for these trucks, 
as well as details about the final provisions for certification and 
implementation of these standards, are discussed in more detail later 
in this notice and in the RIA.
    EPA did not propose, nor is it adopting A/C refrigerant leakage 
standards for Class 2b-8 vocational vehicles, primarily because of the 
number of entities involved in their manufacture and thus the potential 
for different entities besides the chassis manufacturer to be involved 
in the A/C system production and installation.
(d) What manufacturers are not covered by the final standards?
    The NPRM proposed to defer temporarily greenhouse gas emissions and 
fuel consumption standards for any manufacturers of heavy-duty engines, 
manufacturers of combination tractors, and chassis manufacturers for 
vocational vehicles that meet the ``small business'' size criteria set 
by the Small Business Administration (SBA). 13 CFR 121.201 defines a 
small business by the maximum number of employees; for example, this is 
currently 1,000 for heavy-duty vehicle manufacturing and 750 for engine 
manufacturing.\34\ The agencies stated that they would instead consider 
appropriate GHG and fuel consumption standards for these entities as 
part of a future regulatory action. This includes both U.S.-based and 
foreign small-volume heavy-duty manufacturers. To ensure that the 
agencies are aware of which companies would be exempt, the agencies 
proposed to require that such entities submit a declaration describing 
how it qualifies as a small entity under the provisions of 13 CFR 
121.201 to EPA and NHTSA as prescribed in Section V below.
---------------------------------------------------------------------------

    \34\ See Sec.  1036.150 and Sec.  1037.150
---------------------------------------------------------------------------

    EPA and NHTSA were not aware of any manufacturers of HD pickups and 
vans that meet these criteria. For each of the other categories and for 
engines, the agencies identified a small number of manufacturers that 
would appear to qualify as small businesses under the SBA size 
criterion, which were estimated to comprise a negligible percentage of 
the U.S. market.\35\ Therefore, the agencies believed that deferring 
the standards for these companies at this time would have a negligible 
impact on the GHG emission reductions and fuel consumption reductions 
that the program would otherwise achieve. The agencies proposed to 
consider appropriate GHG emissions and fuel consumption standards for 
these entities as part of a future regulatory action.
---------------------------------------------------------------------------

    \35\ Two heavy-duty combination tractor and ten chassis 
manufacturers each comprising less than 0.5 percent of the total 
tractor and vocational market based on Polk Registration Data from 
2003 through 2007, and three engine manufacturing entities based on 
company information included in Hoover's, comprising less than 0.1 
percent of the total heavy-duty engine sales in the United States 
based on 2009 and 2010 EPA certification information.
---------------------------------------------------------------------------

    The Institute for Policy Integrity (IPI) commented that the small 
business exemption proposed in the NPRM was based on the improper 
framework of whether the exemption would have a negligible impact, and 
did not adequately explain why the regulation of small businesses would 
face special compliance and administrative burdens. IPI argued that the 
only proper basis for this exemption would be if the agencies could 
explain how these burdens create costs that exceeded the benefits of 
regulation.
    NHTSA believes that developing standards that are ``appropriate, 
cost-effective, and technologically feasible'' under 49 U.S.C. 
32902(k)(2) includes the authority to exclude certain manufacturers if 
their inclusion would work against these statutory factors. Similarly, 
under section 202(a) of the CAA, EPA may reasonably choose to defer 
regulation of industry segments based on considerations of cost, cost-
effectiveness and available lead time for standards. As noted above, 
small businesses make up a very small percentage of the market and are 
estimated to have a negligible impact on the emissions and fuel 
consumption goals of this program. The short lead time before the 
CO2 standards take effect, the extremely small fuel savings 
and emissions contribution of these entities, and the potential need to 
develop a program that would be structured differently for them (which 
would require more time to determine and adopt), all led to the 
decision that the inclusion of small businesses would not be 
appropriate at this time. Therefore, the final rule exempts small 
businesses as proposed.
    Volvo and EMA stated that by exempting small businesses based on 
the definition from SBA, the rules would create a competitive advantage 
for small businesses over larger entities. EMA commented that the 
exemption should not apply to market segments where a small business 
has a significant share of a particular HD market. Volvo argued that 
the exempted businesses could expand their product offerings or

[[Page 57123]]

sell vehicles on behalf of larger entities, thereby inappropriately 
increasing the scope of the exclusion. The agencies anticipate that the 
gain a manufacturer might achieve by restructuring its practices and 
products to circumvent the standard (which for vocational vehicles 
simply means installing low rolling resistance tires) in the first few 
years of this program will be outweighed by the costs, particularly as 
small businesses anticipate their potential inclusion in the next 
rulemaking.
    Volvo also commented that the agencies should elaborate on the 
requirements for the exemption in greater detail. The agencies agree 
that this may help to clarify the process. As suggested by Volvo, the 
agencies will consider affiliations to other companies and evidence of 
spin-offs for the purpose of circumventing the standards in determining 
whether a business qualifies as a small entity for this exclusion. Each 
declaration must be submitted in writing to EPA and NHTSA as prescribed 
in Section V below. As the agencies gain more experience with this 
exemption, these clarifications may be codified in the regulatory text 
of a future rulemaking.
    Volvo further commented that the agencies were adopting an 
exemption of ``small businesses'' in order to avoid doing a Small 
Business Regulatory Enforcement Fairness Act (SBREFA) and Regulatory 
Flexibility Act (RFA) analysis. The agencies would like to reiterate 
that they have decided not to include small businesses at this time due 
to the factors described above. The discussion on an RFA analysis is 
laid out in Section XII(4).
    The agencies continue to believe that deferring the standards for 
these companies at this time will have a negligible impact on the GHG 
emission reductions and fuel consumption reductions that the program 
would otherwise achieve. Therefore, the final rules include the small 
business exemption as proposed. The specific deferral provisions are 
discussed in more detail in Section II.
    The agencies will consider appropriate GHG emissions and fuel 
consumption standards for these entities as part of a future regulatory 
action.
(e) Light-Duty Vehicle CH4 and N2O Standards 
Flexibility
    After finalization of the N2O and CH4 
standards for light-duty vehicles as part of the 2012-2016 MY program, 
some manufacturers raised concerns that they may have difficulty 
meeting those standards across their light-duty vehicle fleets. In 
response to these concerns, as part of the same Federal Register notice 
as the heavy-duty proposal, EPA requested comments on additional 
options for manufacturers to comply with light-duty vehicle 
N2O and CH4 standards to provide additional near-
term flexibility. Commenters providing comment on this issue supported 
additional flexibility for manufacturers. EPA is finalizing provisions 
allowing manufacturers to use CO2 credits, on a 
CO2-equivalent basis, to meet the N2O and 
CH4 standards, which is consistent with many commenters' 
preferred approach. Manufacturers will have the option of using 
CO2 credits to meet N2O and CH4 
standards on a test group basis as needed for MYs 2012-2016.
(f) Alternative Fuel Engines and Vehicles
    The agencies believe that it is also appropriate to take steps to 
recognize the benefits of flexible-fueled vehicles (FFVs) and dedicated 
alternative-fueled vehicles. In the NPRM, EPA proposed to determine the 
emissions performance of dedicated alternative fuel engines and pickup 
trucks and vans by measuring tailpipe CO2 emissions. NHTSA 
proposed to determine fuel consumption performance of non-electric 
dedicated alternative fuel engines and pickup trucks and vans by 
measuring fuel consumption with the alternative fuel and then 
calculating a petroleum equivalent fuel consumption using a Petroleum 
Equivalency Factor (PEF) that is determined by the Department of 
Energy. NHTSA proposed to treat electric vehicles as having zero fuel 
consumption, comparable to the EPA proposal. Both agencies proposed to 
determine FFV performance in the same way as for GHG emissions for 
light-duty vehicles, with a 50-50 weighting of alternative and 
conventional fuel test results through MY 2015, and a weighting based 
on demonstrated fuel use in the real world after MY 2015 (defaulting to 
an assumption of 100 percent conventional fuel use). This approach was 
considered to be a reasonable and logical way to properly credit 
alternative fuel use in FFVs in the real world without imposing a 
difficult burden of proof on manufacturers. However, unlike in the 
light-duty rule, the agencies do not believe it is appropriate to 
create a provision for additional incentives similar to the 2012-2015 
light-duty incentive program (See 49 U.S.C. 32904) because the HD 
sector does not have the incentives mandated in EISA for light-duty 
FFVs, and so has not relied on the existence of such credits in 
devising compliance strategies for the early model years of this 
program. See 74 FR at 49531. In fact, manufacturers have not in the 
past produced FFV heavy-duty vehicles. On the other hand, the agencies 
sought comment on how to properly recognize the impact of the use of 
alternative fuels, and E85 in particular, in HD pickups and vans, 
including the proper accounting for alternative fuel use in FFVs in the 
real world.\36\ See 75 FR at 74198.
---------------------------------------------------------------------------

    \36\ E85 is a blended fuel consisting of nominally 15 percent 
gasoline and 85 percent ethanol.
---------------------------------------------------------------------------

    The agencies received several comments from natural gas vehicle 
(NGV) interests arguing for greater crediting of NGVs than the proposed 
approach would have provided. Clean Energy, Hayday Farms, Border 
Valley, AGA, Ryder, Encana, and a group of NGV interests commented that 
the NPRM ignored Congress' intent to incentivize the use of NGVs by not 
including the conversion factor that exists in the light-duty statutory 
language. The commenters argued that Congress' intent to incentivize 
NGVs is evident in the formula contained in 49 U.S.C. 32905, which 
deems a gallon equivalent of gaseous fuel to have a fuel content of 
0.15 gallon of fuel. The commenters also argued that Congress 
implicitly intended NGVs to be incentivized in this rulemaking, as 
evidenced by the incentives in the light-duty statutory text. AGA and 
Hayday suggested that the agencies were not including the NGV incentive 
from light-duty because Congress did not explicitly include it in 49 
U.S.C. 32902(k), and argued that this would contradict the agencies' 
inclusion of other incentives similar to the light-duty rule.
    The American Trucking Association expressed support for estimating 
natural gas fuel efficiency by using carbon emissions from natural gas 
rather than energy content to estimate fuel consumption. ATA explained 
that two vehicles can achieve the same fuel efficiency, yet one 
operated on natural gas would have a lower carbon dioxide emissions 
rate. A natural gas conversion factor that uses carbon content versus 
energy content is a more appropriate method for calculating fuel 
consumption, in the commenter's view. A number of other groups 
commented on the appropriate method to use in establishing fuel 
consumption from alternative fueled vehicles. A group of NGV interests, 
Ryder, Border Valley Trading, Waste Management, Robert Bosch and the 
Blue Green Alliance encouraged the agencies to adopt the 0.15 
conversion factor in estimating fuel consumption for FFVs and 
alternative fuel vehicles finalized in the light-duty

[[Page 57124]]

2012-2016 MY vehicle standards. The suggested incentive would 
effectively reduce the calculated fuel consumption for FFVs and 
alternative fuel vehicles by a factor of 85 percent. The commenters 
argued that the incentive is needed for heavy-duty vehicles to 
encourage the use of natural gas and to reduce the nation's dependence 
on petroleum.
    The agencies reassessed the options for evaluating the 
CO2 and fuel consumption performance of alternative fuel 
vehicles in response to comments and because the agencies recognized 
that the treatment of alternate fuel vehicles was one of the few 
provisions in the proposal where the EPA and NHTSA programs were not 
aligned. The agencies conducted an analysis comparing fuel consumption 
calculated based on CO2 emissions \37\ to fuel consumption 
calculated based on gasoline or diesel energy equivalency to evaluate 
impacts of a consistent consumption measurement for all vehicle classes 
covered by this program and to further understand how alternative fuels 
would be impacted by this measurement methodology. In particular the 
agencies evaluated how measuring consumption via CO2 
emissions would hinder or benefit the application of alternative fuels 
versus following similar alternative fuel incentivizing programs 
provided via statute for the Agency's light-duty programs. The analysis 
showed measuring a vehicle's CO2 output converted to fuel 
consumption provided a fuel consumption measurement benefit to those 
vehicles operating on fuels other than gasoline or diesel. For CNG, LNG 
and LPG the benefit is approximately 19 percent to 24 percent, for 
biodiesel and ethanol blends the benefit is approximately 1 percent to 
3 percent, and for electricity and hydrogen fuels the benefit is 100 
percent benefit, as fuel consumption is zero. The agencies also 
considered that the EPA Renewable Fuel Standard,\38\ a separate 
program, requires an increase in the volume of renewable fuels used in 
the U.S. transportation sector. For the fuels covered by the Renewable 
Fuels Standard additional incentives are not needed in this regulation 
given the large volume increases required under the Renewable Fuel 
Standard.
---------------------------------------------------------------------------

    \37\ Fuel consumption calculated from measured CO2 
using conversion factors of 8,887 g CO2/gallon for 
gasoline (for alternative fuel engines that are derived from 
gasoline engines), and 10,180 g CO2/gallon for diesel 
fuel (for alternative fuel engines that are derived from diesel 
engines).
    \38\ EPA is responsible for developing and implementing 
regulations to ensure that transportation fuel sold in the United 
States contains a minimum volume of renewable fuel. The RFS program 
was created under the Energy Policy Act (EPAct) of 2005, and 
expanded under the Energy Independence and Security Act (EISA) of 
2007.
---------------------------------------------------------------------------

    The agencies continue to believe that alternative-fueled vehicles, 
including NGVs, provide fuel consumption benefits that should be, and 
are, accounted for in this program. However, the agencies do not agree 
with the commenters' claim that the NGV incentive contained in EISA, 
and reflected in the light-duty program, is an explicit Congressional 
directive that must also be applied to the heavy-duty program, nor that 
the light-duty incentive for NGVs should be interpreted as an implicit 
Congressional directive for NGVs to be comparably incentivized in the 
heavy-duty program. Further, the agencies believe that the fuel 
consumption benefits that alternative fuel vehicles would obtain 
through measuring CO2 emissions for the EPA program and 
converting CO2 emissions to fuel consumption for the NHTSA 
program accurately reflects their energy benefits. This accurate 
accounting, in conjunction with the volumetric increases required by 
the Renewable Fuels Standard, provides sufficient incentives for these 
vehicles. The agencies continue to believe that the light-duty 
conversion factor is not appropriate for this program. Instead, the 
agencies are finalizing measuring the performance of alternative fueled 
vehicles by measuring CO2 emissions for the EPA program and 
converting CO2 emissions to fuel consumption for the NHTSA 
program. The agencies are also finalizing measuring FFV performance 
with a 50-50 weighting of alternative and conventional fuel test 
results through MY 2015, and an agency- or manufacturer-determined 
weighting based on demonstrated fuel use in the real world after MY 
2015 (defaulting to an assumption of 100 percent conventional fuel 
use).
    The agencies believe this structure accurately reflects the fuel 
consumption of the vehicles while at the same time providing an 
incentive for the alternative fuel use. (For example, natural gas heavy 
duty engines perform 20 to 30 percent better than their diesel and 
gasoline counterparts from a CO2 perspective, and so meet 
the standards adopted in these rules without cost, and indeed will be 
credit generators without cost.) We believe this is a substantial 
enough advantage to spur the market for these vehicles. The calculation 
at the same time does not overestimate the benefit from these 
technologies, which could reduce the effectiveness of the regulation. 
Therefore, the final rules do not include the light-duty 0.15 
conversion factor for NGVs. The agencies would like to clarify that the 
decision not to include an NGV incentive was based on this policy 
determination, not on a belief that incentives present in the light-
duty rule could not be developed for the heavy-duty sector because they 
were not explicitly included in Section 32902(k).
    NHTSA recognizes that EPCA/EISA promotes incentives for alternative 
fueled vehicles for different purposes than does the CAA, and that 
there may be additional energy and national security benefits that 
could be achieved through increasing fleet percentages of natural gas 
and other alternative-fueled vehicles. More alternative-fueled vehicles 
on road would arguably displace petroleum-fueled vehicles, and thereby 
increase both U.S. energy and national security by reducing the 
nation's dependence on foreign oil.
    However, a rule that adopts identical incentive provisions reduces 
industry reporting burdens and NHTSA's monitoring burden. In addition, 
the agencies are concerned that providing greater incentives under 
EPCA/EISA might lead to little increased production of alternative 
fueled vehicles. If this were the case, then the benefits of 
harmonization could outweigh any potential gains from providing greater 
incentives. It is also consistent with Executive Order 13563.\39\
---------------------------------------------------------------------------

    \39\ EO 13563 states that an agency shall ``tailor its 
regulations to impose the least burden on society, consistent with 
obtaining regulatory objectives, taking into account, among other 
things, and to the extent practicable, the costs of cumulative 
regulations,'' and ``promote such coordination, simplification, and 
harmonization'' as will reduce redundancy, inconsistency, and costs 
of multiple regulatory requirements.
---------------------------------------------------------------------------

    Adopting the same incentive provisions could also have benefits for 
the public, the regulated industries, and the agencies. This approach 
allows manufacturers to project clear benefits for the application of 
GHG-reduction and fuel efficiency technologies, thus spurring their 
adoption.
    This combined rulemaking by EPA and NHTSA is designed to regulate 
two separate characteristics of heavy duty vehicles: Greenhouse gas 
emissions (GHG) and fuel consumption. In the case of diesel or gasoline 
powered vehicles, there is a one-to-one relationship between these two 
characteristics. Each gallon of gasoline combusted by a truck engine 
generates approximately 8,887 grams of CO2; and each gallon 
of diesel fuel burned generates about 10,180 grams of CO2. 
Because no available technologies reduce tailpipe CO2 
emissions per gallon of fuel combusted, any rule that limits tailpipe 
CO2 emissions is

[[Page 57125]]

effectively identical to a rule that limits fuel consumption. 
Compliance by a truck manufacturer with the NHTSA fuel economy rule 
assures compliance with the EPA rule, and vice versa.
    For alternatively fueled vehicles, which use no petroleum, the 
situation is different. For example, a natural gas vehicle that 
achieves approximately the same fuel economy as a diesel powered 
vehicle would emit 20 percent less CO2; and a natural gas 
vehicle with the same fuel economy as a gasoline vehicle would emit 30 
percent less CO2. Yet natural gas vehicles consume no 
petroleum. To the extent that the goal of the NHTSA fuel economy 
portion of this rulemaking is to curb petroleum use, crediting natural 
gas vehicles with zero fuel consumption per mile could contribute to 
achieving that goal. Similar differences between oil consumption and 
greenhouse gas emissions would apply to electric vehicles, hybrid 
electric vehicles, and biofuel-powered vehicles.
    NHTSA notes that the purpose of EPCA/EISA is not merely to curb 
petroleum use--it is more generally to secure energy independence, 
which can be achieved by reducing petroleum use. The value of 
incentivizing natural gas, electric vehicles, biofuels, hydrogen, or 
other alt fuel vehicles for energy independence is limited to the 
extent that the alternative fuels may be imported.
    In the recent rulemaking for light-duty vehicles, EPA and NHTSA 
have followed the light duty specific statutory provision that treats 
one gallon of alternative fuel as equivalent to 0.15 gallons of 
gasoline until MY 2016, when performance on the EPA CO2 
standards is measured based on actual emissions. 75 FR at 25433. 
Following that MY 2012-2015 approach in this heavy duty program would 
mean that, for example, a natural gas powered truck would have 
attributed to it 20 percent less CO2 emissions than a 
comparable diesel powered truck, but 85 percent less fuel consumption. 
Engine manufacturers with a relatively large share of alternative-fuel 
products would likely have an easier time complying with NHTSA's 
average fuel economy standard than with EPA's GHG standard. Similarly, 
engine manufacturers with a relatively small share of alternative-fuel 
products would have a relatively easier time complying with EPA's 
CO2 standard than with NHTSA's fuel economy standard. In 
that way, the rule would not differ from the light duty vehicle rules.
    Instead, in this program, EPA and NHTSA are establishing identical 
rules. Fuel consumption for alternatively-powered vehicles will be 
calculated according to their tailpipe CO2 emissions. In 
that way, there will be a one-to-one relationship between fuel economy 
and tailpipe CO2 emissions for all vehicles. However, this 
might not result in a one-to-one relationship between petroleum 
consumption and GHG emissions for all vehicles. On the other hand, it 
could have the disadvantage of not doing more to encourage some cost-
effective means of reducing petroleum consumption by trucks, and the 
accompanying energy security costs. By attributing to natural gas 
engines only 20 percent less fuel consumption than comparable diesel 
engines, because they emit 20 percent less CO2, rather than 
attributing to them a much larger percentage reduction in fuel 
consumption, because they use no petroleum, this uniform approach to 
rulemaking provides less of an incentive for technologies that reduce 
consumption of petroleum-based fuels.
    In the future, the Agencies will consider the possibility of 
proposing standards in a way that more fully reflects differences in 
fuel consumption and greenhouse gas emissions. Under such standards, 
any given vehicle might ``over-comply'' with the fuel economy standard, 
but might ``under-comply'' with the greenhouse gas standard. Therefore, 
in meeting the fleet-wide requirements, a manufacturer would need to 
meet both standards using all available options, such as credit trading 
and technology mix. Allowing for two distinct standards might enable 
manufacturers to achieve the twin goals of reducing greenhouse gas 
emissions and decreasing consumption of petroleum-based fuels in a more 
cost-effective manner.

D. Summary of Costs and Benefits of the HD National Program

    This section summarizes the projected costs and benefits of the 
final NHTSA fuel consumption and EPA GHG emissions standards. These 
projections helped to inform the agencies' choices among the 
alternatives considered and provide further confirmation that the final 
standards are an appropriate choice within the spectrum of choices 
allowable under the agencies' respective statutory criteria. NHTSA and 
EPA have used common projected costs and benefits as the bases for our 
respective standards.
    The agencies have analyzed in detail the projected costs, fuel 
savings, and benefits of the final GHG and fuel consumption standards. 
Table I-5 shows estimated lifetime discounted program costs (including 
technological outlays), fuel savings, and benefits for all heavy-duty 
vehicles projected to be sold in model years 2014-2018 over these 
vehicles' lives. The benefits include impacts such as climate-related 
economic benefits from reducing emissions of CO2 (but not 
other GHGs) and reductions in energy security externalities caused by 
U.S. petroleum consumption and imports. The analysis also includes 
economic impacts stemming from additional heavy-duty vehicle use 
attributable to fuel savings, such as the economic damages caused by 
accidents, congestion and noise. Note that benefits reflect on 
estimated values for the social cost of carbon (SCC), as described in 
Section VIII.G.
    The costs, fuel savings, and benefits summarized here are slightly 
higher than at proposal, reflecting the use of 2009 (versus 2008) 
dollars, some minor changes to our cost estimates in response to 
comments, and a change to the 2011 Annual Energy Outlook (AEO) estimate 
of economic growth and future fuel prices. In aggregate, these changes 
lead to an increased estimate of the net benefits of the final action 
compared to the proposal.

 Table I-5--Estimated Lifetime Discounted Costs, Fuel Savings, Benefits,
    and Net Benefits for 2014-2018 Model Year Heavy-Duty Vehiclesa b
                            [Billions, 2009$]
------------------------------------------------------------------------
 
------------------------------------------------------------------------
               Lifetime Present Value\c\--3% Discount Rate
------------------------------------------------------------------------
Program Costs...........................................            $8.1
Fuel Savings............................................             $50
Benefits................................................            $7.3
Net Benefits\d\.........................................             $49
------------------------------------------------------------------------
                  Annualized Value\e\--3% Discount Rate
------------------------------------------------------------------------
Annualized Costs........................................            $0.4
Fuel Savings............................................            $2.2
Annualized Benefits.....................................            $0.4
Net Benefits\d\.........................................            $2.2
------------------------------------------------------------------------
               Lifetime Present Value\c\--7% Discount Rate
------------------------------------------------------------------------
Program Costs...........................................            $8.1
Fuel Savings............................................             $34
Benefits................................................            $6.7
Net Benefits\d\.........................................             $33
------------------------------------------------------------------------
                  Annualized Value\e\--7% Discount Rate
------------------------------------------------------------------------
Annualized Costs........................................            $0.6
Fuel Savings............................................            $2.6
Annualized Benefits.....................................            $0.5
Net Benefits\d\.........................................            $2.5
------------------------------------------------------------------------
Notes:

[[Page 57126]]

 
\a\ The agencies estimated the benefits associated with four different
  values of a one ton CO2 reduction (model average at 2.5% discount
  rate, 3%, and 5%; 95th percentile at 3%), which each increase over
  time. For the purposes of this overview presentation of estimated
  costs and benefits, however, we are showing the benefits associated
  with the marginal value deemed to be central by the interagency
  working group on this topic: the model average at 3% discount rate, in
  2009 dollars. Section VIII.F provides a complete list of values for
  the 4 estimates.
\b\ Note that net present value of reduced GHG emissions is calculated
  differently than other benefits. The same discount rate used to
  discount the value of damages from future emissions (SCC at 5, 3, and
  2.5 percent) is used to calculate net present value of SCC for
  internal consistency. Refer to Section VIII.F for more detail.
\c\ Present value is the total, aggregated amount that a series of
  monetized costs or benefits that occur over time is worth now (in year
  2009 dollar terms), discounting future values to the present.
\d\ Net benefits reflect the fuel savings plus benefits minus costs.
\e\ The annualized value is the constant annual value through a given
  time period (2012 through 2050 in this analysis) whose summed present
  value equals the present value from which it was derived.

    Table I-6 shows the estimated lifetime reductions in CO2 
emissions (in million metric tons (MMT)) and fuel consumption for all 
heavy-duty vehicles sold in the model years 2014-2018. The values in 
Table I-6 are projected lifetime totals for each model year and are not 
discounted. The two agencies' standards together comprise the HD 
National Program, and the agencies' respective GHG emissions and fuel 
consumption standards, jointly, are the source of the benefits and 
costs of the HD National Program.

                   Table I-6--Estimated Lifetime Reductions in Fuel Consumption and CO2 Emissions for 2014-2018 Model Year HD Vehicles
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 All heavy-duty vehicles                      2014 MY         2015 MY         2016 MY         2017 MY         2018 MY          Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fuel (billion gallons)..................................            4.0             3.6             3.6             5.1             5.8            22.1
Fuel (billion barrels)..................................            0.10            0.09            0.08            0.12            0.14            0.53
CO2 (MMT)a..............................................           50.2            44.8            44.0            62.8            71.7           273
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note:
\a\ Includes upstream and downstream CO2 reductions.

    Table I-7 shows the estimated lifetime discounted benefits for all 
heavy-duty vehicles sold in model years 2014-2018. Although the 
agencies estimated the benefits associated with four different values 
of a one ton CO2 reduction ($5, $22, $36, $66), for the 
purposes of this overview presentation of estimated benefits the 
agencies are showing the benefits associated with one of these marginal 
values, $22 per ton of CO2, in 2009 dollars and 2010 
emissions. Table I-7 presents benefits based on the $22 per ton of 
CO2 value. Section VIII.F presents the four marginal values 
used to estimate monetized benefits of CO2 reductions and 
Section VIII presents the program benefits using each of the four 
marginal values, which represent only a partial accounting of total 
benefits due to omitted climate change impacts and other factors that 
are not readily monetized. The values in the table are discounted 
values for each model year of vehicles throughout their projected 
lifetimes. The analysis includes other economic impacts such as energy 
security, and other externalities such as impacts on accidents, 
congestion and noise. However, the model year lifetime analysis 
supporting the program omits other impacts such as benefits related to 
non-GHG emission reductions.\40\ The lifetime discounted benefits are 
shown for one of four different SCC values considered by EPA and NHTSA. 
The values in Table I-7 do not include costs associated with new 
technology required to meet the GHG and fuel consumption standards.
---------------------------------------------------------------------------

    \40\ Non-GHG emissions and health-related impacts were estimated 
for the calendar year analysis. See Section VII for more information 
about non-GHG emission impacts and Section VIII for more information 
about non-GHG-related health impacts.

   Table I-7--Estimated Lifetime Discounted Benefits for 2014-2018 Model Year HD Vehicles Assuming the Model Average, 3% Discount Rate SCC Valuea b c
                                                               [billions of 2009 dollars]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                    Model year
                 Discount rate (percent)                 -----------------------------------------------------------------------------------------------
                                                               2014            2015            2016            2017            2018            Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
3.......................................................           $10.7            $9.4            $9.2           $13.2           $14.9             $57
7.......................................................             8.3             6.9             6.6             9.2            10.1              41
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\a\ The analysis includes impacts such as the economic value of reduced fuel consumption and accompanying climate-related economic benefits from
  reducing emissions of CO2 (but not other GHGs), and reductions in energy security externalities caused by U.S. petroleum consumption and imports. The
  analysis also includes economic impacts stemming from additional heavy-duty vehicle use, such as the economic damages caused by accidents, congestion
  and noise.
\b\ Note that net present value of reduced CO2 emissions is calculated differently than other benefits. The same discount rate used to discount the
  value of damages from future emissions (SCC at 5, 3, and 2.5 percent) is used to calculate net present value of SCC for internal consistency. Refer to
  Section VIII.F for more detail, including a list of all four SCC values, which increase over time.
\c\ Benefits in this table include fuel savings.

    Table I-8 shows the agencies' estimated lifetime fuel savings, 
lifetime CO2 emission reductions, and the monetized net 
present values of those fuel savings and CO2 emission 
reductions. The gallons of fuel and CO2 emission reductions 
are projected lifetime values for all vehicles sold in the model years 
2014-2018. The

[[Page 57127]]

estimated fuel savings in billions of barrels and the GHG reductions in 
million metric tons of CO2 shown in Table I-8 are totals for 
the five model years throughout their projected lifetime and are not 
discounted. The monetized values shown in Table I-8 are the summed 
values of the discounted monetized-fuel consumption and monetized-
CO2 reductions for the five model years 2014-2018 throughout 
their lifetimes. The monetized values in Table I-8 reflect both a 3 
percent and a 7 percent discount rate as noted.

   Table I-8--Estimated Lifetime Reductions and Associated Discounted
         Monetized Benefits for 2014-2018 Model Year HD Vehicles
                   [Monetized values in 2009 dollars]
------------------------------------------------------------------------
                                        Amount        $ Value (billions)
------------------------------------------------------------------------
Fuel Consumption Reductions.....  0.53 billion        $50.1, 3% discount
                                   barrels.            rate $34.4, 7%
                                                       discount rate.
CO2 Emission Reductions \a\       273 MMT CO2.......  $5.8 \b\.
 Valued assuming $22/ton CO2 in
 2010.
------------------------------------------------------------------------
Notes:
\a\ Includes both upstream and downstream CO2 emission reductions.
\b\ Note that net present value of reduced CO2 emissions is calculated
  differently than other benefits. The same discount rate used to
  discount the value of damages from future emissions (SCC at 5, 3, and
  2.5 percent) is used to calculate net present value of SCC for
  internal consistency. Refer to Section VIII.F for more detail.

    Table I-9 shows the estimated incremental and total technology 
outlays for all heavy-duty vehicles for each of the model years 2014-
2018. The technology outlays shown in Table I-9 are for the industry as 
a whole and do not account for fuel savings associated with the 
program.

            Table I-9--Estimated Incremental Technology Outlays for 2014-2018 Model Year HD Vehicles
                                           [Billions of 2009 dollars]
----------------------------------------------------------------------------------------------------------------
                                                            2014 MY  2015 MY  2016 MY  2017 MY  2018 MY   Total
----------------------------------------------------------------------------------------------------------------
All Heavy-Duty Vehicles...................................     $1.6     $1.4     $1.5     $1.6     $2.0     $8.1
----------------------------------------------------------------------------------------------------------------

    Table I-10 shows the agencies' estimated incremental cost increase 
of the average new heavy-duty vehicle for each model year 2014-2018. 
The values shown are incremental to a baseline vehicle and are not 
cumulative.

         Table I-10--Estimated Incremental Increase in Average Cost for 2014-2018 Model Year HD Vehicles
                                             [2009 Dollars per unit]
----------------------------------------------------------------------------------------------------------------
                                                            2014 MY    2015 MY    2016 MY    2017 MY    2018 MY
----------------------------------------------------------------------------------------------------------------
Combination Tractors.....................................     $6,019     $5,871     $5,677     $6,413     $6,215
HD Pickups & Vans........................................        165        215        422        631      1,048
Vocational Vehicles......................................        329        320        397        387        378
----------------------------------------------------------------------------------------------------------------

    Both costs and benefits presented in this section are in comparison 
to a reference case with no improvements in fuel consumption or 
greenhouse gas emissions in model years 2014 to 2018.

E. Program Flexibilities

    For each of the heavy-duty vehicle and heavy-duty engine categories 
for which we are adopting respective standards, EPA and NHTSA are also 
finalizing provisions designed to give manufacturers a degree of 
flexibility in complying with the standards. These final provisions 
have enabled the agencies to consider overall standards that are more 
stringent and that will become effective sooner than we could consider 
with a more rigid program, one in which all of a manufacturer's similar 
vehicles or engines would be required to achieve the same emissions or 
fuel consumption levels, and at the same time.\41\ We believe that 
incorporating carefully structured regulatory flexibility provisions 
into the overall program is an important way to achieve each agency's 
goals for the program.
---------------------------------------------------------------------------

    \41\ NHTSA notes that it has greater flexibility in the HD 
program to include consideration of credits and other flexibilities 
in determining appropriate and feasible levels of stringency than it 
does in the light-duty CAFE program. Cf. 49 U.S.C. 32902(h), which 
applies to light-duty CAFE but not heavy-duty fuel efficiency under 
49 U.S.C. 32902(k).
---------------------------------------------------------------------------

    NHTSA's and EPA's flexibility provisions are essentially identical 
in structure and function. Within combination tractor and vocational 
vehicle categories and within heavy-duty engines, we are finalizing 
four primary types of flexibility: Averaging, banking, and trading 
(ABT) provisions; early credits; advanced technology credits (including 
hybrid powertrains); and innovative technology credit provisions. The 
final ABT provisions are patterned on existing EPA and NHTSA ABT 
programs and will allow a vehicle manufacturer to reduce CO2 
emission and fuel consumption levels further than the level of the 
standard for one or more vehicles to generate ABT credits. The 
manufacturer can use those credits to offset higher emission or fuel 
consumption levels in the same averaging set, ``bank'' the credits for 
later use, or ``trade'' the credits to another manufacturer. For HD 
pickups and vans, we are finalizing a fleet

[[Page 57128]]

averaging system very similar to the light-duty GHG and CAFE fleet 
averaging system.
    At proposal, we restricted the use of the ABT provisions of the 
program to vehicles or engines within the same regulatory subcategory. 
This meant that credit exchanges could only happen between similar 
vehicles meeting the same standards. We proposed this approach for two 
reasons. First, we were concerned about a level playing field between 
different manufacturers who may not participate equally in the various 
truck and engine markets covered in the regulation. Second, we were 
concerned about the uncertainties inherent in credit calculations that 
are based on projections of lifetime emissions for different vehicles 
in wholly different vehicle markets. In response to comments, we have 
revised our ABT provisions to provide greater flexibility while 
continuing to provide assurance that the projected reductions in fuel 
consumption and GHG emissions will be achieved. We are relaxing the 
restriction on averaging, banking, and trading of credits between the 
various regulatory subcategories, by defining three HD vehicle 
averaging sets: Light Heavy-Duty (Classes 2b-5); Medium Heavy-Duty 
(Class 6-7); and Heavy Heavy-Duty (Class 8). This allows the use of 
credits between vehicles within the same weight class. This means that 
a Class 8 day cab tractor can exchange credits with a Class 8 high roof 
sleeper tractor but not with a smaller Class 7 tractor. Also, a Class 8 
vocational vehicle can exchange credits with a Class 8 tractor. We are 
adopting these revisions based on comments from the regulated industry 
that convinced us these changes would allow the broadest trading 
possible while maintaining a level playing field among the various 
market segments. However, we are restricting trading between engines 
and chassis, even within the same vehicle class.
    The agencies believe that restricting trading to within the same 
eight classes as EPA's existing criteria pollutant program (i.e. Heavy-
Heavy Duty, Light Heavy-Duty, Medium Heavy-Duty), but not restricting 
trading between vehicle or engine type (such as combination tractors), 
and restricting between engines and chassis for the same vehicle type, 
is appropriate and reasonable. We do not expect emissions from engines 
and vehicles--when restricted by weight class--to be dissimilar. We 
therefore expect that the lifetime vehicle performance and emissions 
levels will be very similar across these defined categories, and the 
estimated credit calculations will fairly ensure the expected fuel 
consumption and GHG reductions.
    The agencies considered even broader averaging, banking, and 
trading provisions but decided that in this first phase of regulation, 
it would be prudent to start with the program described here, which 
will regulate greenhouse gas emissions and fuel consumption from this 
sector for the first time and provide considerable early reductions as 
well as opportunities to learn about technical and other issues that 
can inform future rulemakings. In the future we intend to consider 
whether additional cost savings could be realized through broader 
trading provisions and whether such provisions could be designed so as 
to address any other relevant concerns.
    Reducing the cost of regulation through broader use of market tools 
is a high priority for the Administration. See Executive Order 13563 
and in particular section 1(b)(5) and section 4. Consistent with this 
principle, we intend to seek public comment through a Notice of Data 
Availability after credit trading begins in 2013, the first year we 
expect manufacturers to begin certifying 2014 model year vehicles, on 
whether broader credit trading is more appropriate in developing the 
next phase of heavy-duty regulations. We believe that input will be 
better informed by the work the agencies and the regulated industry 
will have put into implementing this first phase of heavy-duty 
regulations.
    Through this public process, emphasizing the Administration's 
strong preference for flexible approaches and maximizing the use of 
market tools, the agencies intend to fully consider whether broader 
credit trading is more appropriate in developing the next phase of 
heavy-duty regulations.
    This program thus does not allow credits to be exchanged between 
heavy-duty vehicles and light-duty vehicles, nor can credits be traded 
from heavy-duty vehicle fleets to light-duty vehicle fleets and vice 
versa.
    The engine ABT provisions are also changed from the proposal and 
now are the same as in EPA's existing criteria pollutant emission 
rules. The agencies have broadened the averaging sets to include both 
FTP-certified and SET-certified engines in the same averaging set. For 
example, a SET-certified engine intended for a Class 8 tractor can 
exchange credits with a FTP-certified engine intended for a Class 8 
vocational vehicle.
    The agencies are finalizing three year deficit carry-forward 
provisions for heavy-duty engines and vehicles within a limited time 
frame. This flexibility is expected to provide an opportunity for 
manufacturers to make necessary technological improvements and reduce 
the overall cost of the program without compromising overall 
environmental and fuel economy objectives. This flexibility, similar to 
the flexibility the agencies have offered under the light-duty vehicle 
program, is intended to assist the broad goal of harmonizing the two 
agencies' standards while preserving the flexibility of manufacturers 
of vehicles and engines in meeting the standards, to the extent 
appropriate and required by law. During the MYs 2014-2018 manufacturers 
are expected to go through the normal business cycle of redesigning and 
upgrading their heavy-duty engine and vehicle products, and in some 
cases introducing entirely new vehicles and engines not on the market 
today. As explained in the following paragraph, the carry-forward 
provision will allow manufacturers the time needed to incorporate 
technology to achieve GHG reductions and improve fuel economy during 
the vehicle redesign process.
    We received comments from Center for Biological Diversity against 
the need to offer the deficit carry-forward flexibility. CBD has stated 
that allowing manufacturers to carry-forward deficits for up to three 
years would incentivize delays in investment and technological 
innovation and allow for the generation of additional tons of GHG 
emissions that may be prevented today. However, the deficit carry-
forward flexibility (as well as ABT generally) has enabled the agencies 
to consider overall standards that are more stringent and that will 
become effective at an earlier period than we could consider with a 
more rigid program. The agencies also believe this flexibility is an 
important aspect of the program, as it avoids the much higher costs 
that would occur if manufacturers needed to add or change technology at 
times other than their scheduled redesigns, i.e. the cost of adopting a 
new engine or vehicle platform mid-production or mid-design. This time 
period would also provide manufacturers the opportunity to plan for 
compliance using a multi-year time frame, again consistent with normal 
business practice. Over these four model years, there would be an 
opportunity for manufacturers to evaluate practically all of their 
vehicle and engine model platforms and add technology in a cost 
effective way to control GHG emissions and improve fuel economy.
    As noted above, in addition to ABT, the other primary flexibility 
provisions in this program involve opportunities to generate early 
credits, advanced technology credits (including for use of

[[Page 57129]]

hybrid powertrains), and innovative technology credits. For the early 
credits and advanced technology credits, the agencies sought comment on 
the appropriateness of providing a 1.5x multiplier as an incentive for 
their use. We received a number of comments supporting the idea of a 
credit multiplier, arguing it was an appropriate means to incentivize 
the early compliance and advanced technologies the agencies sought. We 
received other comments suggesting a multiplier was unnecessary. After 
considering the comments, the agencies have decided to finalize a 1.5x 
multiplier consistent with our request for comments. We believe that 
given the very short lead time of the program and the nascent nature of 
the advanced technologies identified in the proposal, that a 1.5x 
multiplier is an effective means to bring technology forward into the 
heavy-duty sector sooner than would otherwise occur. In addition, 
advanced technology credits could be used anywhere within the heavy 
duty sector (including both vehicles and engines), but early credits 
would be restricted to use within the same defined averaging set 
generating the credit.
    For other technologies which can reduce CO2 and fuel 
consumption, but for which there do not yet exist established methods 
for quantifying reductions, the agencies still wish to encourage the 
development of such innovative technologies, and are therefore adopting 
special ``innovative technology'' credits. These innovative technology 
credits will apply to technologies that are shown to produce emission 
and fuel consumption reductions that are not adequately recognized on 
the current test procedures and that are not yet in widespread use in 
the heavy-duty sector. Manufacturers will need to quantify the 
reductions in fuel consumption and CO2 emissions that the 
technology is expected to achieve, above and beyond those achieved on 
the existing test procedures. As with ABT, the use of innovative 
technology credits will only be allowed for use among vehicles and 
engines of the same defined averaging set generating the credit, as 
described above. The credit multiplier will not be used for innovative 
technology credits.
    CBD argued that including any opportunities for manufacturers to 
earn credits in the final rule would violate NHTSA's statutory mandate 
to implement a program designed to achieve the maximum feasible 
improvement.
    NHTSA strongly believes that creating credit flexibilities for 
manufacturers for this first phase of the HD National Program is fully 
consistent with the agency's obligation to develop a fuel efficiency 
improvement program designed to achieve the maximum feasible 
improvement. EISA gives NHTSA broad authority to develop ``compliance 
and enforcement protocols'' that are ``appropriate, cost-effective, and 
technologically feasible,'' and the agency believes that compliance 
flexibilities such as the opportunity to earn and use credits to meet 
the standards are a reasonable and appropriate interpretation of that 
authority, along with the other compliance and enforcement provisions 
developed for this final rule. Unlike in NHTSA's light-duty program, 
where the agency is restricted from considering the availability of 
credits in determining the maximum feasible level of stringency for the 
fuel economy standards,\42\ in this HD National Program, NHTSA and EPA 
have based the levels of stringency in part on our assumptions of the 
use of available flexibilities that have been built into the program to 
incentivize over-compliance in some respects, to balance out potential 
under-compliance in others.
---------------------------------------------------------------------------

    \42\ See 49 U.S.C. 32902(h).
---------------------------------------------------------------------------

    By assuming the use of credits for compliance, the agencies were 
able to set the fuel consumption/GHG standards at more stringent levels 
than would otherwise have been feasible. Greater improvements in fuel 
efficiency will occur under more stringent standards; manufacturers 
will simply have greater flexibility to determine where and how to make 
those improvements than they would have without credit options. 
Further, this is consistent with EOs 12866 and 13563, which encourage 
agencies to design regulations that promote innovation and flexibility 
where possible.\43\
---------------------------------------------------------------------------

    \43\ EO 12866 states that an agency must ``design its 
regulations in the most cost-effective manner to achieve the 
regulatory objective * * * consider[ing] incentives for innovation * 
* * [and] flexibility,'' among other factors; EO 13563 directs 
agencies to ``seek to identify, as appropriate, means to achieve 
regulatory goals that are designed to promote innovation,'' and 
``identify and consider regulatory approaches that * * * maintain 
flexibility.''
---------------------------------------------------------------------------

    A detailed discussion of each agency's ABT, early credit, advanced 
technology, and innovative technology provisions for each regulatory 
category of heavy-duty vehicles and engines is found in Section IV 
below.

F. EPA and NHTSA Statutory Authorities

(1) EPA Authority
    Title II of the CAA provides for comprehensive regulation of mobile 
sources, authorizing EPA to regulate emissions of air pollutants from 
all mobile source categories. When acting under Title II of the CAA, 
EPA considers such issues as technology effectiveness, its cost (both 
per vehicle, per manufacturer, and per consumer), the lead time 
necessary to implement the technology, and based on this the 
feasibility and practicability of potential standards; the impacts of 
potential standards on emissions reductions of both GHGs and non-GHGs; 
the impacts of standards on oil conservation and energy security; the 
impacts of standards on fuel savings by customers; the impacts of 
standards on the truck industry; other energy impacts; as well as other 
relevant factors such as impacts on safety.
    This final action implements a specific provision from Title II, 
section 202(a).\44\ Section 202(a)(1) of the CAA states that ``the 
Administrator shall by regulation prescribe (and from time to time 
revise) * * * standards applicable to the emission of any air pollutant 
from any class or classes of new motor vehicles * * *, which in his 
judgment cause, or contribute to, air pollution which may reasonably be 
anticipated to endanger public health or welfare.'' With EPA's December 
2009 final findings that certain greenhouse gases may reasonably be 
anticipated to endanger public health and welfare and that emissions of 
GHGs from section 202 (a) sources cause or contribute to that 
endangerment, section 202(a) requires EPA to issue standards applicable 
to emissions of those pollutants from new motor vehicles.
---------------------------------------------------------------------------

    \44\ See 42 U.S.C. 7521 (a). A number of commenters believed 
that the GHG program was being adopted pursuant to section 202 
(a)(3)(A) and that the lead time requirements of section 202 
(a)(3)(C) therefore apply. This is mistaken. Section 202 (a)(3)(A) 
applies to standards for emissions of hydrocarbons, carbon monoxide, 
oxides of nitrogen, and particulate matter from heavy-duty vehicles 
and engines. This does not include the GHGs regulated under the 
standards in today's action. This comment is addressed further in 
the Response to Comment document.
---------------------------------------------------------------------------

    Any standards under CAA section 202(a)(1) ``shall be applicable to 
such vehicles * * * for their useful life.'' Emission standards set by 
the EPA under CAA section 202(a)(1) are technology-based, as the levels 
chosen must be premised on a finding of technological feasibility. 
Thus, standards promulgated under CAA section 202(a) are to take effect 
only ``after providing such period as the Administrator finds necessary 
to permit the development and application of the requisite technology, 
giving appropriate consideration to the cost of compliance within such 
period'' (section 202(a)(2);

[[Page 57130]]

see also NRDC v. EPA, 655 F. 2d 318, 322 (DC Cir. 1981)). EPA is 
afforded considerable discretion under section 202(a) when assessing 
issues of technical feasibility and availability of lead time to 
implement new technology. Such determinations are ``subject to the 
restraints of reasonableness'', which ``does not open the door to 
`crystal ball' inquiry.'' NRDC, 655 F. 2d at 328, quoting International 
Harvester Co. v. Ruckelshaus, 478 F. 2d 615, 629 (DC Cir. 1973). 
However, ``EPA is not obliged to provide detailed solutions to every 
engineering problem posed in the perfection of the trap-oxidizer. In 
the absence of theoretical objections to the technology, the agency 
need only identify the major steps necessary for development of the 
device, and give plausible reasons for its belief that the industry 
will be able to solve those problems in the time remaining. The EPA is 
not required to rebut all speculation that unspecified factors may 
hinder `real world' emission control.'' NRDC, 655 F. 2d at 333-34. In 
developing such technology-based standards, EPA has the discretion to 
consider different standards for appropriate groupings of vehicles 
(``class or classes of new motor vehicles''), or a single standard for 
a larger grouping of motor vehicles (NRDC, 655 F. 2d at 338).
    Although standards under CAA section 202(a)(1) are technology-
based, they are not based exclusively on technological capability. EPA 
has the discretion to consider and weigh various factors along with 
technological feasibility, such as the cost of compliance (See section 
202(a) (2)), lead time necessary for compliance (section 202(a)(2)), 
safety (See NRDC, 655 F. 2d at 336 n. 31) and other impacts on 
consumers, and energy impacts associated with use of the technology. 
See George E. Warren Corp. v. EPA, 159 F.3d 616, 623-624 (DC Cir. 1998) 
(ordinarily permissible for EPA to consider factors not specifically 
enumerated in the CAA). See also Entergy Corp. v. Riverkeeper, Inc., 
129 S.Ct. 1498, 1508-09 (2009) (congressional silence did not bar EPA 
from employing cost-benefit analysis under Clean Water Act absent some 
other clear indication that such analysis was prohibited; rather, 
silence indicated discretion to use or not use such an approach as the 
agency deems appropriate).
    In addition, EPA has clear authority to set standards under CAA 
section 202(a) that are technology forcing when EPA considers that to 
be appropriate, but is not required to do so (as compared to standards 
set under provisions such as section 202(a)(3) and section 
213(a)(3)).\45\ EPA has interpreted a similar statutory provision, CAA 
section 231, as follows:
---------------------------------------------------------------------------

    \45\ One commenter mistakenly stated that section 202 (a) 
standards must be technology-forcing, but the provision plainly does 
not require EPA to adopt technology-forcing standards. See further 
discussion in Section III.A below.
---------------------------------------------------------------------------

    While the statutory language of section 231 is not identical to 
other provisions in title II of the CAA that direct EPA to establish 
technology-based standards for various types of engines, EPA interprets 
its authority under section 231 to be somewhat similar to those 
provisions that require us to identify a reasonable balance of 
specified emissions reduction, cost, safety, noise, and other factors. 
See, e.g., Husqvarna AB v. EPA, 254 F.3d 195 (DC Cir. 2001) (upholding 
EPA's promulgation of technology-based standards for small non-road 
engines under section 213(a)(3) of the CAA). However, EPA is not 
compelled under section 231 to obtain the ``greatest degree of emission 
reduction achievable'' as per sections 213 and 202 of the CAA, and so 
EPA does not interpret the Act as requiring the agency to give 
subordinate status to factors such as cost, safety, and noise in 
determining what standards are reasonable for aircraft engines. Rather, 
EPA has greater flexibility under section 231 in determining what 
standard is most reasonable for aircraft engines, and is not required 
to achieve a ``technology forcing'' result (70 FR 69664 and 69676, 
November 17, 2005).
    This interpretation was upheld as reasonable in NACAA v. EPA, 489 
F.3d 1221, 1230 (DC Cir. 2007). CAA section 202(a) does not specify the 
degree of weight to apply to each factor, and EPA accordingly has 
discretion in choosing an appropriate balance among factors. See Sierra 
Club v. EPA, 325 F.3d 374, 378 (DC Cir. 2003) (even where a provision 
is technology-forcing, the provision ``does not resolve how the 
Administrator should weigh all [the statutory] factors in the process 
of finding the `greatest emission reduction achievable' ''). See also 
Husqvarna AB v. EPA, 254 F. 3d 195, 200 (DC Cir. 2001) (great 
discretion to balance statutory factors in considering level of 
technology-based standard, and statutory requirement ``to [give 
appropriate] consideration to the cost of applying * * * technology'' 
does not mandate a specific method of cost analysis); see also Hercules 
Inc. v. EPA, 598 F. 2d 91, 106 (DC Cir. 1978) (``In reviewing a 
numerical standard the agencies must ask whether the agency's numbers 
are within a zone of reasonableness, not whether its numbers are 
precisely right''); Permian Basin Area Rate Cases, 390 U.S. 747, 797 
(1968) (same); Federal Power Commission v. Conway Corp., 426 U.S. 271, 
278 (1976) (same); Exxon Mobil Gas Marketing Co. v. FERC, 297 F. 3d 
1071, 1084 (DC Cir. 2002) (same).
(a) EPA Testing Authority
    Under section 203 of the CAA, sales of vehicles are prohibited 
unless the vehicle is covered by a certificate of conformity. EPA 
issues certificates of conformity pursuant to section 206 of the Act, 
based on (necessarily) pre-sale testing conducted either by EPA or by 
the manufacturer. The Heavy-duty Federal Test Procedure (Heavy-duty 
FTP) and the Supplemental Engine Test (SET) are used for this purpose. 
Compliance with standards is required not only at certification but 
throughout a vehicle's useful life, so that testing requirements may 
continue post-certification. Useful life standards may apply an 
adjustment factor to account for vehicle emission control deterioration 
or variability in use (section 206(a)).
    EPA established the Light-duty FTP for emissions measurement in the 
early 1970s. In 1976, in response to the Energy Policy and Conservation 
Act, EPA extended the use of the Light-duty FTP to fuel economy 
measurement (See 49 U.S.C. 32904(c)). EPA can determine fuel efficiency 
of a vehicle by measuring the amount of CO2 and all other 
carbon compounds (e.g., total hydrocarbons and carbon monoxide (CO)), 
and then, by mass balance, calculating the amount of fuel consumed.
(b) EPA Enforcement Authority
    Section 207 of the CAA grants EPA broad authority to require 
manufacturers to remedy vehicles if EPA determines there are a 
substantial number of noncomplying vehicles. In addition, section 205 
of the CAA authorizes EPA to assess penalties of up to $37,500 per 
vehicle for violations of various prohibited acts specified in the CAA. 
In determining the appropriate penalty, EPA must consider a variety of 
factors such as the gravity of the violation, the economic impact of 
the violation, the violator's history of compliance, and ``such other 
matters as justice may require.''
(2) NHTSA Authority
    In 1975, Congress enacted the Energy Policy and Conservation Act 
(EPCA), mandating a regulatory program for motor vehicle fuel economy 
to meet the various facets of the need to conserve energy. In December 
2007, Congress

[[Page 57131]]

enacted the Energy Independence and Securities Act (EISA), amending 
EPCA to require, among other things, the creation of a medium- and 
heavy-duty fuel efficiency program for the first time. This mandate in 
EISA represents a major step forward in promoting EPCA's goals of 
energy independence and security, and environmental and national 
security.
    NHTSA has primary responsibility for fuel economy and consumption 
standards, and assures compliance with EISA through rulemaking, 
including standard-setting; technical reviews, audits and studies; 
investigations; and enforcement of implementing regulations including 
penalty actions. This final action implements Section 32902(k)(2) of 
EISA, which instructs NHTSA to create a fuel efficiency improvement 
program for ``commercial medium- and heavy-duty on-highway vehicles and 
work trucks'' \46\ by rulemaking, which is to include standards, test 
methods, measurement metrics, and enforcement protocols. See 49 U.S.C. 
32902(k)(2). Congress directed that the standards, test methods, 
measurement metrics, and compliance and enforcement protocols be 
``appropriate, cost-effective, and technologically feasible'' for the 
vehicles to be regulated, while achieving the ``maximum feasible 
improvement'' in fuel efficiency.
---------------------------------------------------------------------------

    \46\ ``Commercial medium- and heavy-duty on-highway vehicles'' 
are defined at 49 U.S.C. 32901(a)(7), and ``work trucks'' are 
defined at (a)(19).
---------------------------------------------------------------------------

    NHTSA has clear authority to design and implement a fuel efficiency 
program for vehicles and work trucks under EISA, and was given broad 
discretion to balance the statutory factors in Section 32902(k)(2) in 
developing fuel consumption standards to achieve the maximum feasible 
improvement. Since this is the first rulemaking that NHTSA has 
conducted under 49 U.S.C. 32902(k)(2), the agency interpreted these 
elements and factors in the context of setting standards, choosing 
metrics, and determining test methods and compliance/enforcement 
mechanisms. Discussion of the application of these factors can be found 
in Section III below. Congress also gave NHTSA the authority to set 
separate standards for different classes of these vehicles, but 
required that all standards adopted provide not less than four full 
model years of regulatory lead-time and three full model years of 
regulatory stability.
    In EISA, Congress required NHTSA to prescribe separate average fuel 
economy standards for passenger cars and light trucks in accordance 
with the provisions in 49 U.S.C. Section 32902(b), and to prescribe 
standards for work trucks and commercial medium- and heavy-duty 
vehicles in accordance with the provisions in 49 U.S.C. 32902(k). See 
49 U.S.C. Section 32902(b)(1). Congress also added in EISA a 
requirement that NHTSA shall issue regulations prescribing fuel economy 
standards for at least 1, but not more than 5, model years. See 49 
U.S.C. 32902(b)(3)(B). For purposes of the fuel efficiency standards 
that the agency proposed for HD vehicles and engines, the NPRM stated 
an interpretation of the statute that the 5-year maximum limit did not 
apply to standards promulgated in accordance with 49 U.S.C. 32902(k), 
given the language in Section 32902(b)(1). Based on this 
interpretation, NHTSA proposed that the standards ultimately finalized 
for HD vehicles and engines would remain in effect indefinitely at 
their 2018 or 2019 model year levels until amended by a future 
rulemaking action. In any future rulemaking action to amend the 
standards, NHTSA would ensure not less than four full model years of 
regulatory lead-time and three full model years of regulatory 
stability. NHTSA sought comment on its interpretation of EISA.
    Robert Bosch LLC (Bosch) commented that the absence of an 
expiration date for the standards proposed in the NPRM could violate 49 
U.S.C. 32902, which it interpreted as requiring the MD/HD program to 
have standards that expire in five years. Section 32902(k)(3), which 
lays out the requirements for the MD/HD program, specifies the minimum 
regulatory lead and stability times, as described above, but does not 
specify a maximum duration period. In contrast, Section 32902(b)(3)(B) 
lays out the minimum and maximum durations of standards to be 
established in a rulemaking for the light-duty program, but prescribes 
no minimum lead or stability time. Bosch argued that as 49 U.S.C. 
Section 32902(k)(3) does not require a maximum duration period, 
Congress intended that NHTSA take the maximum duration period specified 
for the light-duty program in Section 32902(b)(3)(B), five years, and 
apply it to Section 32902(k)(3). Bosch also argued, however, that the 
minimum duration period should not be carried over from the light-duty 
to the heavy-duty section, as a minimum duration period for HD was 
specified in Section 32902(k)(3).
    NHTSA has revisited this issue and continues to believe that it is 
reasonable to assume that if Congress intended for the HD/MD regulatory 
program to be limited by the timeline prescribed in Subsection 
(b)(3)(B), it would have either mentioned HD/MD vehicles in that 
subsection or included the same timeline in Subsection (k).\47\ In 
addition, in order for Subsection (b)(3)(B) to be interpreted to apply 
to Subsection (k), the agency would need to give less than full weight 
to the earlier phrase in the statute directing the Secretary to 
prescribe standards for ``work trucks and commercial medium-duty or 
heavy-duty on-highway vehicles in accordance with Subsection (k).'' 49 
U.S.C. 32902(b)(1)(C). Instead, this direction would need to be read to 
mean ``in accordance with Subsection (k) and the remainder of 
Subsection (b).'' NHTSA believes this interpretation would be 
inappropriate. Interpreting ``in accordance with Subsection (k)'' to 
mean something indistinct from ``in accordance with this Subsection'' 
goes against the canon that statutes should not be interpreted in a way 
that ``render[s] language superfluous.'' Dobrova v. Holder, 607 F.3d 
297, 302 (2d Cir. 2010), quoting Mendez v. Holder, 566 F. 3d 316, 321-
22 (2d Cir. 2009). Based on this reasoning, NHTSA believes the more 
reasonable and appropriate approach is reflected in the proposal, and 
the final rules therefore follow this approach.
---------------------------------------------------------------------------

    \47\ ``[W]here Congress includes particular language in one 
section of a statute but omits it in another section of the same 
Act, it is generally presumed that Congress acts intentionally and 
purposely in the disparate inclusion or exclusion.'' Russello v. 
United States, 464 U.S. 16, 23 (1983), quoting U.S. v. Wong Kim Bo, 
472 F.2d 720, 722 (5th Cir 1972)., See also Mayo v. Questech, Inc., 
727 F.Supp. 1007, 1014 (E.D.Va. 1989) (conspicuous absence of 
provision from section where inclusion would be most logical signals 
Congress did not intend for it to be implied).
---------------------------------------------------------------------------

    Another commenter, CBD, expressed concern that lack of an 
expiration date meant that the standards would remain indefinitely, 
thus forgoing the possibility of increased stringency in the future. 
CBD argued that this violated NHTSA's statutory duty to set maximum 
feasible standards. NHTSA disagrees that the indefinite duration of the 
standards in this rule would prevent the agency from setting future 
standards at the maximum feasible level in future rulemakings. The 
absence of an expiration date for these standards should not be 
interpreted to mean that there will be no future rulemakings to 
establish new MD/HD fuel efficiency standards for MYs 2019 and beyond--
the agencies have already previewed the possibility of such a 
rulemaking in other parts of this final rule preamble. Therefore, NHTSA 
believes this concern is unnecessary.

[[Page 57132]]

(a) NHTSA Testing Authority
    49 U.S.C. Section 32902(k)(2) states that NHTSA must adopt and 
implement appropriate, cost-effective, and technologically feasible 
test methods and measurement metrics as part of the fuel efficiency 
improvement program. For this program, manufacturers will test and 
conduct modeling to determine GHG emissions and fuel consumption 
performance, and EPA and NHTSA will perform validation testing. The 
results of the validation tests will be used by EPA to create a 
finalized reporting that confirms the manufacturer's final model year 
GHG emissions and fuel consumption results, which each agency will use 
to enforce compliance with its standards.
(v) NHTSA Enforcement Authority
(i) Overview
    The NPRM proposed a compliance and enforcement program that 
included civil penalties for violations of the fuel efficiency 
standards. 49 U.S.C. 32902(k)(2) states that NHTSA must adopt and 
implement appropriate, cost-effective, and technologically feasible 
compliance and enforcement protocols for the fuel efficiency 
improvement program. Congress gave DOT broad discretion to fashion its 
fuel efficiency improvement program and thus necessarily did not speak 
directly or specifically as to the nature of the compliance and 
enforcement protocols that would be best suited for effectively 
supporting the yet-to-be-designed-and-established program. Instead, it 
left the matter generally to the Secretary. Congress' approach is 
unlike CAFE enforcement for passenger cars and light trucks, where 
Congress specified the precise details of a program and provided that a 
manufacturer either complies with standards or pays civil penalties.
    The statute is silent with respect to how ``protocol'' should be 
interpreted. The term ``protocol'' is imprecise and thus Congress' 
choice of that term affords the agency substantial breadth of 
discretion. For example, in a case interpreting Section 301(c)(2) of 
the Comprehensive Environmental Response, Compensation, and Liability 
Act (CERCLA), the DC Circuit noted that the word ``protocols'' has many 
definitions that are not much help. Kennecott Utah Copper Corp., Inc. 
v. U.S. Dept. of Interior, 88 F.3d. 1191, 1216 (DC Cir. 1996). Section 
301(c)(2) of CERCLA prescribed the creation of two types of procedures 
for conducting natural resources damages assessments. The regulations 
were to specify (a) ``standard procedures for simplified assessments 
requiring minimal field observation'' (the ``Type A'' rules), and (b) 
``alternative protocols for conducting assessments in individual 
cases'' (the ``Type B'' rules).\48\ The court upheld the challenged 
provisions, which were a part of a set of rules establishing a step-by-
step procedure to evaluate options based on certain criteria, and to 
make a decision and document the results.
---------------------------------------------------------------------------

    \48\ State of Ohio v. U.S. Dept. of Interior, 880 F.2d 432, 439 
(DC Cir. 1989).
---------------------------------------------------------------------------

    Taking the considerations above into account, including Congress' 
instructions to adopt and implement compliance and enforcement 
protocols, and the Secretary's authority to formulate policy and make 
rules to fill gaps left, implicitly or explicitly, by Congress, the 
agency interpreted ``protocol'' in the context of EISA as authorizing 
the agency to determine both whether manufacturers have complied with 
the standards, and to establish suitable and reasonable enforcement 
mechanisms and decision criteria for non-compliance. Therefore, NHTSA 
interpreted its authority to develop an enforcement program to include 
the authority to determine and assess civil penalties for non-
compliance.
    Several commenters disagreed with this interpretation. Volvo and 
EMA commented that the penalties proposed by NHTSA exceeded the 
authority granted to the agency by Congress, and Volvo commented that 
the fact that Congress did not adopt an entirely new statute for the HD 
program should be interpreted to mean that provisions adopted for the 
light-duty program should apply to the HD program as well. Daimler 
argued that it was likely that EISA did not give NHTSA the authority to 
assess civil penalties, and Navistar and EMA argued that NHTSA could 
not have the authority as Congress did not expressly grant it.
    NHTSA continues to believe that it is reasonable to interpret 
``compliance and enforcement protocols'' to include authority to impose 
civil penalties. Where a statute does not specify an approach, the 
discretion to do so is left to the agency. When Congress has 
``explicitly left a gap for an agency to fill, there is an express 
delegation of authority to the agency to elucidate a specific provision 
of the statute by regulation.'' United States. v. Mead, 533 U.S. 218, 
227 (2001), quoting Chevron v. NRDC, 467 U.S. 837, 843-44 (1984). The 
delegation of authority may be implicit rather than express. Id. at 
229. NHTSA believes it would be unreasonable to assume that Congress 
intended to create a hollow regulatory program without a mechanism for 
effective enforcement. Further, interpreting ``enforcement protocols'' 
to mean not more than ``compliance protocols'' would go against the 
canon noted above that statutes should not be interpreted in a way that 
``render[s] language superfluous.'' Dobrova v. Holder, 607 F.3d 297, 
302 (2d Cir. 2010), quoting Mendez v. Holder 566 F. 3d 316, 321-22 (2d 
Cir. 2009). The interpretation urged by the commenters would render an 
entire program superfluous.
    Further, NHTSA believes that Congress would have anticipated that 
compliance and enforcement protocols would include civil penalties for 
the HD sector, given that penalties are an integral part of a product 
standards program and given the long precedent of civil penalties for 
the light-duty sector. The agency disagrees with the argument that the 
HD program would have appeared in a wholly separate statute if Congress 
had not intended the penalty program for light-duty to apply to it. The 
inclusion of the MD/HD program in Title 329 does not mean that Congress 
intended for the boundaries and differences between the separate 
sections to be ignored. Rather, this argument leads to the opposite 
conclusion that the fact that Congress created a new section for the HD 
program, instead of simply amending the existing light-duty program to 
include ``work trucks and other vehicles'' in addition to automobiles, 
means the agency should assume that Congress acted intentionally when 
it created two wholly separate programs and respect their distinctions. 
Therefore, consistent with the statutory interpretation proposed in the 
NPRM, the final rule includes penalties for non-compliance with the 
fuel efficiency standards.
(ii) Penalty Levels
    NHTSA proposed to adopt penalty levels equal to those in EPA's 
existing heavy-duty program, in order to provide adequate deterrence as 
well as consistency with the GHG regulation. The proposed maximum 
penalty levels were $37,500.00 per vehicle or engine.
    Several manufacturers commented that the penalty levels should be 
limited to those mandated in the light-duty program. Volvo and Daimler 
argued that Congress intended lower penalties for the HD program than 
were proposed in the NPRM, because they believed that Congress had 
expressly or implicitly intended for the HD program to be included in 
the penalty calculation of Section 32912(b). That section prescribes 
penalty levels for violators under Section 32902 of ``$5 multiplied

[[Page 57133]]

by each tenth (0.1) of a mile a gallon by which the applicable average 
fuel economy standard under that section exceeds the average fuel 
economy,'' \49\ calculated and applied to automobiles. Volvo further 
argued that NHTSA was relying upon the CAA as the statutory basis for 
the penalty levels.
---------------------------------------------------------------------------

    \49\ This fine was increased by 49 CFR 578.6, which provides 
that ``Except as provided in 49 U.S.C. 32912(c), a manufacturer that 
violates a standard prescribed for a model year under 49 U.S.C. 
32902 is liable to the United States Government for a civil penalty 
of $5.50 multiplied by each 0.1 of a mile a gallon by which the 
applicable average fuel economy standard under that section exceeds 
the average fuel economy.''
---------------------------------------------------------------------------

    NHTSA recognizes that Section 329 contains a detailed penalty 
scheme, for light-duty vehicle CAFE standards. However, Section 
32902(k)(2) explicitly directs NHTSA to ``adopt and implement 
appropriate test methods, measurement metrics, fuel economy standards, 
and compliance and enforcement protocols,'' in the creation of the new 
HD program. NHTSA continues to believe that this broad Congressional 
mandate should be interpreted based on a plain text reading, which 
includes the authority to determine compliance and enforcement 
protocols that will be effective and appropriate for this new sector of 
regulation. NHTSA also believes that reading Section 32912 to apply to 
the new HD program would contradict Congress' broad mandate for the 
agency to establish new measurement metrics and a compliance and 
enforcement program. Further, interpreting the requirement to create 
``enforcement protocols'' for HD vehicles to mean that NHTSA should 
rely on the enforcement provisions for light-duty vehicles would go 
against the canon noted above that statutes should not be interpreted 
in a way that ``render[s] language superfluous.'' Dobrova v. Holder, 
607 F.3d 297, 302 (2d Cir. 2010), quoting Mendez v. Holder 566 F. 3d 
316, 321-22 (2d Cir. 2009).
    NHTSA believes that Section 32912 does not apply to the new HD 
program for several other reasons. First, this section uses a fuel 
economy metric, miles/gallon, while the HD program is built around a 
fuel consumption metric, per the requirement to develop a ``fuel 
efficiency improvement program'' and the agencies' conclusion, 
supported by NAS, that a fuel consumption metric is a much more 
reasonable choice than a fuel economy metric for HD vehicles given 
their usage as work vehicles. Second, this section specifies a 
calculation for automobiles, a vehicle class which is confined to the 
light-duty rule. In addition, the HD program prescribes fuel 
consumption standards, not average fuel economy standards.
    Finally, NHTSA believes that if Congress had intended for a pre-
determined penalty scheme to apply to the new HD program, it would have 
been specific. Instead, Congress explicitly directed the agency to 
develop a new measurement, compliance, and enforcement scheme. 
Consistent with the statutory interpretation of the duration of the 
standards, NHTSA believes that if Congress intended for particular 
penalty levels to be used in Section 32902(k)(3), it would have either 
included a reference to those levels or included a reference in 32912 
to the vehicles and metrics regulated by 32902(k)(3). See Russello v. 
United States, 464 U.S. 16, 23 (1983), quoting United States v. Wong 
Kim Bo, 472 F.2d 720, 722 (5th Cir 1972) (``[W]here Congress includes 
particular language in one section of a statute but omits it in another 
section of the same Act, it is generally presumed that Congress acts 
intentionally and purposely in the disparate inclusion or exclusion.'') 
Instead, the absence of such language could mean either that Congress 
did not contemplate the specific penalty levels to be used, or that 
Congress left the choice of specific penalty levels to the agency. See 
Alliance for Community Media v. F.C.C. 529 F. 3d 763, 779 (6th Cir. 
2008) (absence of a statutory deadline in one section but not others 
meant that Congress authorized but did not require it in that section).
    NHTSA believes that, based on EPA's experience regulating this 
sector for criteria pollutants, the proposed maximum penalty is at an 
appropriate level to create deterrence for non-compliance, while at the 
same time, not so high as to create undue hardship for manufacturers. 
Therefore, the final rule retains the maximum penalty level proposed in 
the NPRM.

G. Future HD GHG and Fuel Consumption Rulemakings

    This final action represents a first regulatory step by NHTSA and 
EPA to address the multi-faceted challenges of reducing fuel use and 
greenhouse gas emissions from these vehicles. By focusing on existing 
technologies and well-developed regulatory tools, the agencies are able 
to adopt rules that we believe will produce real and important 
reductions in GHG emissions and fuel consumption within only a few 
years. Within the context of this regulatory time frame, our program is 
very aggressive--with limited lead time compared to historic heavy-duty 
regulations--but pragmatic in the context of technologies that are 
available and that can be reasonably implemented during the regulatory 
time frame.
    While we are now only finalizing this first step, it is worthwhile 
to consider how the next regulatory step may be designed. Technologies 
such as hybrid drivetrains, advanced bottoming cycle engines, and full 
electric vehicles are promoted in this first step through incentive 
concepts as discussed in Section IV, but we believe that these advanced 
technologies will not be necessary to meet the final standards. Today's 
standards are premised on the use of existing technologies given the 
short lead time, as discussed in Section III, below. When we begin work 
to develop a possible next set of regulatory standards, the agencies 
expect these advanced technologies to be an important part of the 
regulatory program and will consider them in setting the stringency of 
any standards beyond the 2018 model year.
    We will not only consider the progress of technology in our future 
regulatory efforts, but the agencies are also committed to fully 
considering a range of regulatory approaches. To more completely 
capture the complex interactions of the total vehicle and the potential 
to reduce fuel consumption and GHG emissions through the optimization 
of those interactions may require a more sophisticated approach to 
vehicle testing than we are adopting today for the largest heavy-duty 
vehicles. In future regulations, the agencies expect to fully evaluate 
the potential to expand the use of vehicle compliance models to reflect 
engine and drivetrain performance. Similarly, we intend to consider the 
potential for complete vehicle testing using a chassis dynamometer, not 
only as a means for compliance, but also as a complementary tool for 
the development of more complex vehicle modeling approaches. In 
considering these more comprehensive regulatory approaches, the 
agencies will also reevaluate whether separate regulation of trucks and 
engines remains necessary.
    In addition to technology and test procedures, vehicle and engine 
drive cycles are an important part of the overall approach to 
evaluating and improving vehicle performance. EPA, working through the 
WP.29 Global Technical Regulation process, has actively participated in 
the development of a new World Harmonized Duty Cycle for heavy-duty 
engines. EPA is committed to bringing forward these new procedures as 
part of our overall comprehensive approach for controlling

[[Page 57134]]

criteria pollutant and GHG emissions. However, we believe the important 
issues and technical work related to setting new criteria pollutant 
emissions standards appropriate for the World Harmonized Duty Cycle are 
significant and beyond the scope of this rulemaking. Therefore, the 
agencies are not adopting these test procedures in this action, but we 
are ready to work with interested stakeholders to adopt these 
procedures in a future action.
    As noted above, the agencies also intend to further investigate 
possibilities of expanded credit trading across the heavy-duty sector. 
As part of this effort, the agencies will investigate the degree to 
which the issue of credit trading is connected with complete vehicle 
testing procedures.
    As with this program, our future efforts will be based on 
collaborative outreach with the stakeholder community and will be 
focused on a program that delivers on our energy security and 
environmental goals without restricting the industry's ability to 
produce a very diverse range of vehicles serving a wide range of needs.

II. Final GHG and Fuel Consumption Standards for Heavy-Duty Engines and 
Vehicles

    This section describes the standards and implementation dates that 
the agencies are finalizing for the three categories of heavy-duty 
vehicles and engines. The agencies have performed a technology analysis 
to determine the level of standards that we believe will be cost-
effective, feasible, and appropriate in the lead time provided. This 
analysis, described in Section III and in more detail in the RIA 
Chapter 2, considered for each of the regulatory categories:
     The level of technology that is incorporated in current 
new engines and trucks,
     Forecasts of manufacturers' product redesign schedules,
     The available data on corresponding CO2 
emissions and fuel consumption for these engines and vehicles,
     Technologies that would reduce CO2 emissions 
and fuel consumption and that are judged to be feasible and appropriate 
for these vehicles and engines through the 2018 model year,
     The effectiveness and cost of these technologies, and
     Projections of future U.S. sales for trucks and engines.

A. What vehicles will be affected?

    EPA and NHTSA are finalizing standards for heavy-duty engines and 
also for what we refer to generally as ``heavy-duty vehicles.'' In 
general, these standards will apply for the model year 2014 and later 
engines and vehicles, although some standards do not apply until 2016 
or 2017. The EPA standards will apply throughout the useful life of the 
engine or vehicle, just as existing criteria emission standards apply 
throughout the useful life. As noted in Section I, for purposes of this 
preamble and rules, the term ``heavy-duty or ``HD'' applies to all 
highway vehicles and engines that are not regulated by the light-duty 
vehicle, light-duty truck and medium-duty passenger vehicle greenhouse 
gas and CAFE standards issued for MYs 2012-2016. Thus, in this notice, 
unless specified otherwise, the heavy-duty category incorporates all 
vehicles rated with GVWR greater than 8,500 pounds, and the engines 
that power these vehicles, except for MDPVs. The CAA defines heavy-duty 
vehicles as trucks, buses or other motor vehicles with GVWR exceeding 
6,000 pounds. See CAA section 202(b)(3). In the context of the CAA, the 
term HD as used in these final rules thus refers to a subset of these 
vehicles and engines. EISA section 103(a)(3) defines a `commercial 
medium- and heavy-duty on-highway vehicle' as an on-highway vehicle 
with GVWR of 10,000 pounds or more.\50\ EISA section 103(a)(6) defines 
a `work truck' as a vehicle that is rated at between 8,500 and 10,000 
pounds gross vehicle weight and is not a medium-duty passenger 
vehicle.\51\ Therefore, the term ``heavy-duty vehicles'' in this 
rulemaking refers to both work trucks and commercial medium- and heavy-
duty on-highway vehicles as defined by EISA. Heavy-duty engines 
affected by the standards are those that are installed in commercial 
medium- and heavy-duty vehicles, except for the engines installed in 
vehicles certified to a complete vehicle emissions standard based on a 
chassis test, which would be addressed as a part of those complete 
vehicles, and except for engines used exclusively for stationary power 
when the vehicle is parked. The agencies' scope is the same with the 
exception of recreational vehicles (or motor homes), as discussed 
above. The standards that EPA is finalizing today cover recreational 
on-highway vehicles, while NHTSA limited its scope in the proposal to 
not include these vehicles. See Section I.A above.
---------------------------------------------------------------------------

    \50\ Codified at 49 U.S.C. 32901(a)(7).
    \51\ EISA Section 103(a)(6) is codified at 49 U.S.C. 
32901(a)(19). EPA defines medium-duty passenger vehicles as any 
complete vehicle between 8,500 and 10,000 pounds GVWR designed 
primarily for the transportation of persons which meet the criteria 
outlined in 40 CFR 86.1803-01. The definition specifically excludes 
any vehicle that (1) has a capacity of more than 12 persons total 
or, (2) is designed to accommodate more than 9 persons in seating 
rearward of the driver's seat or, (3) has a cargo box (e.g., pickup 
box or bed) of six feet or more in interior length. (See the Tier 2 
final rulemaking, 65 FR 6698, February 10, 2000.)
---------------------------------------------------------------------------

    The NPRM did not include an export exclusion in NHTSA's fuel 
consumption standards. Oshkosh Corporation commented that NHTSA should 
add an export exclusion in order to accommodate the testing and 
delivery needs of manufacturers of vehicles intended for export. NHTSA 
agrees with this comment and Section 535.3 of the final rule specifies 
such an exclusion.
    EPA and NHTSA are finalizing standards for each of the following 
categories, which together comprise all heavy-duty vehicles and all 
engines used in such vehicles. In order to most appropriately regulate 
the broad range of heavy-duty vehicles and engines, the agencies are 
setting separate engine and vehicle standards for the combination 
tractors and Class 2b through 8 vocational vehicles. The engine 
standards and test procedures for engines installed in the tractors and 
vocational vehicles are discussed within the preamble sections for 
combination tractors and vocational vehicles, respectively. The 
agencies are establishing standards for heavy-duty pickups and vans 
that apply to the entire vehicle;--there are no separate engine 
standards.
    As discussed in Section IX, the agencies are not adopting GHG 
emission and fuel consumption standards for trailers at this time. In 
addition, the agencies are not adopting standards at this time for 
engine, chassis, and vehicle manufacturers which are small businesses 
(as defined by the Small Business Administration). More detailed 
discussion of each regulatory category is included in the subsequent 
sections below.

B. Class 7 and 8 Combination Tractors

    EPA is finalizing CO2 standards and NHTSA is finalizing 
fuel consumption standards for new Class 7 and 8 combination tractors. 
The standards are for the tractor cab, with a separate standard for the 
engine that is installed in the tractor. Together these standards would 
achieve reductions of up to 23 percent compared to the model 2010 
baseline level. As discussed below, EPA is finalizing its proposal to 
adopt the existing useful life definitions for Class 7 and 8 tractors 
and the heavy-duty engines installed in them. NHTSA and EPA are 
finalizing revised fuel consumption and GHG emissions standards for 
tractors, and finalizing as proposed engine standards for heavy-duty 
engines in Class 7 and 8 tractors. The agencies' analyses, as discussed

[[Page 57135]]

briefly below and in more detail later in this preamble and in the RIA 
Chapter 2, show that these standards are feasible and appropriate under 
each agency's respective statutory authorities.
    EPA is also finalizing standards to control N2O, 
CH4, and HFC emissions from Class 7 and 8 combination 
tractors. The final heavy-duty engine standards for both N2O 
and CH4 and details of the standard are included in the 
discussion in Section II.E.1.b and II.E.2.b, respectively. The final 
air conditioning leakage standards applying to tractor manufacturers to 
address HFC emissions are discussed in Section II.E.5.
    The agencies are finalizing CO2 emissions and fuel 
consumption standards for the combination tractors that reflect 
reductions that can be achieved through improvements in the tractor 
(such as aerodynamics), tires, and other vehicle systems. The agencies 
are also finalizing heavy-duty engine standards for CO2 
emissions and fuel consumption that reflect technological improvements 
in combustion and overall engine efficiency.
    The agencies have analyzed the feasibility of achieving the 
CO2 and fuel consumption standards, and have identified 
means of achieving the standards that are technically feasible in the 
lead time afforded, economically practicable and cost-effective. EPA 
and NHTSA present the estimated costs and benefits of the standards in 
Section III. In developing the final rules, the agencies have evaluated 
the kinds of technologies that could be utilized by engine and tractor 
manufacturers, as well as the associated costs for the industry and 
fuel savings for the consumer and the magnitude of the national 
CO2 and fuel savings that may be achieved.
    The agencies received comments from multiple stakeholders regarding 
the definition and classification of ``combination tractors.'' The 
commenters raised three key issues. First, EMA/TMA, Navistar and DTNA 
requested that both agencies use the same definition for ``tractor'' or 
``truck tractor'' in the final rules. EPA proposed a definition for 
``tractor'' in Sec.  1037.801 (see the proposed rule published November 
30, 2010, 75 FR 74402) which stated that ``tractor'' means a vehicle 
capable of pulling trailers that is not intended to carry significant 
cargo other than cargo in the trailer, or any other vehicle intended 
for the primary purpose of pulling a trailer. For purposes of this 
definition, the term ''cargo'' includes permanently attached equipment 
such as fire-fighting equipment. The following vehicles are tractors: 
any vehicle sold to an ultimate purchaser with a fifth wheel coupling 
installed; any vehicle sold to an ultimate purchaser with the rear 
portion of the frame exposed where the length of the exposed portion is 
5.0 meters or less. See Sec.  1037.620 for special provisions related 
to vehicles sold to secondary vehicle manufacturers in this condition. 
The following vehicles are not tractors: Any vehicle sold to an 
ultimate purchaser with an installed cargo carrying feature (for 
example, this would include dump trucks and cement trucks); any vehicle 
lacking a fifth wheel coupling sold to an ultimate purchaser with the 
rear portion of the frame exposed where the length of the exposed 
portion is more than 5.0 meters.
    NHTSA proposed to use the 49 CFR 571.3 definition of ``truck 
tractor'' in 49 CFR 535.4 (see the proposed rule published November 30, 
2010, 75 FR 74440) which stated that ``truck tractor'' means a truck 
designed primarily for drawing other motor vehicles and not so 
constructed as to carry a load other than a part of the weight of the 
vehicle and the load so drawn.
    Second, EMA/TMA, NTEA and Navistar expressed concerns over, and 
requested the removal of, the proposed language that all vehicles with 
sleeper cabs would be classified as tractors. The commenters argued 
that because there are vocational vehicles manufactured with sleeper 
cabs that operate as vocational vehicles and not as tractors, those 
vehicles should be treated the same as all other vocational vehicles. 
Third, eleven different commenters requested that the agencies 
subdivide tractors into line-haul tractors and vocational tractors and 
treat each based upon their operational characteristics: vocational 
tractors, which operate at lower speeds offroad or in stop-and-go city 
driving as vocational vehicles; and line-haul tractors, which operate 
at highway speeds on interstate roadways over long distances, as line-
haul tractors.
    In response to the first comment, the agencies have decided to 
standardize the definition of tractor by using the long-standing NHTSA 
definition of ``truck tractor'' established in 49 CFR 571.3. 49 CFR 
571.3(b) states that a ``truck tractor means a truck designed primarily 
for drawing other motor vehicles and not so constructed as to carry a 
load other than a part of the weight of the vehicle and the load so 
drawn.'' EPA's proposed definition for ``tractor'' in the NPRM was 
similar to the NHTSA definition, but included some additional language 
to require a fifth wheel coupling and an exposed frame in the rear of 
the vehicle where the length of the exposed portion is 5.0 meters or 
less. EMA and Navistar argued that these two different definitions 
could lead to confusion if the agencies applied their requirements for 
truck tractors differently from each other. The commenters suggested 
that the EPA definition was more complicated than necessary, and that 
the simpler NHTSA definition should be used by both agencies as the 
base definition of truck tractor.
    The agencies agree that the definitions should be standardized and 
that the NHTSA definition is sufficient and includes the essential 
requirement that a truck tractor is a truck designed ``primarily for 
drawing other motor vehicles and not so constructed as to carry a load 
other than a part of the weight of the vehicle and the load so drawn.'' 
EPA's proposed tractor definition was intended to be functionally 
equivalent to NHTSA's definition based on design, but to be more 
objective by including the criteria related to ``fifth wheels'' and 
exposed rear frame. However, EPA no longer believes that such 
additional criteria are needed for implementation. NHTSA established 
the definition for truck tractor in 49 CFR 571.3(b) years ago,\52\ and 
has not encountered any notable problems with its application. 
Nevertheless, because the NHTSA definition relies more on design intent 
than EPA's proposed definition, we recognize that there may be some 
questions regarding how the agencies would apply the NHTSA definition 
being finalized to certain unique vehicles. For example, many of the 
common automobile and boat transport trucks may look similar to 
tractors, but the agencies would not consider them to meet the 
definition, because they have the capability to carry one or several 
vehicles as cargo with or without a trailer attached, and therefore are 
not ``constructed as to carry a load other than a part of the weight of 
the vehicle and the load so drawn.'' Similarly, a ``dromedary'' style 
truck that has the capability to carry a large load of cargo with or 
without drawing a trailer would also not qualify as a tractor.\53\ Even 
though these particular vehicles identified could potentially draw 
other motor vehicles like a trailer, they have also been designed to 
carry cargo with or without the trailer attached. NHTSA has previously 
interpreted its definition for ``truck tractor'' as excluding these 
specific vehicles like the dromedary and

[[Page 57136]]

automobile/boat transport vehicles. Tow trucks have also been excluded 
from the category of truck tractor. On the other hand, it is worth 
clarifying that designs that allow cargo to be carried in the passenger 
compartment, the sleeper compartment, or external toolboxes would not 
exclude a vehicle from the tractor category. The agencies plan to 
continue with this approach for the HD fuel efficiency and GHG 
standards, which means that these particular vehicles will be subject 
to the vocational vehicle standards and not the tractor standards, but 
vehicles that did meet the definition above for ``tractor'' will be 
subject to the combination tractor standards.
---------------------------------------------------------------------------

    \52\ 33 FR 19703, December 25, 1968.
    \53\ A dromedary is a box, deck or plate mounted behind the cab 
to carry freight or cargo.
---------------------------------------------------------------------------

    In response to the second comment, the agencies have decided not to 
classify vocational vehicles with sleeper cabs as tractors. In the 
NPRM, the agencies proposed that vocational vehicles with sleeper cabs 
be classified as tractors out of concern that a vehicle could initially 
be manufactured as a straight truck vocational vehicle with a sleeper 
cab and, soon after introduction into commerce, be converted to a 
combination tractor as a means to circumvent the Class 8 sleeper cab 
regulations. Commenters who addressed this issue generally disagreed 
with the agencies' concern. EMA/TMA, for example, argued that it is 
expensive and difficult for a manufacturer to change a vehicle from a 
straight truck to a tractor, because of modifications required to the 
vehicle, such as to the vehicle's air brake system, and also because of 
the manufacturers ultimate responsibility for recertification to 
NHTSA's safety standards. EMA/TMA also argued that straight trucks are 
often built with sleeper cabs to perform the functions of a vocational 
type vehicle and not the functions of a line-haul tractor. NTEA also 
provided an example of a straight truck (Expediter Cab) that can be 
built with a sleeper cab and a cargo-carrying body, which it argued 
should be classified as a vocational vehicle and not a tractor.
    Upon further consideration, the agencies agree that vocational 
vehicles with sleeper cabs are more appropriately classified as 
vocational vehicles than as tractors. The comments discussed above help 
to illustrate the reasons for building a vocational vehicle with a 
sleeper cab and the difficulties of converting a straight truck to a 
tractor. Moreover, 49 U.S.C. Chapter 301 requires any service 
organization making such modifications to be responsible for 
recertification to all applicable Federal motor vehicle safety 
standards, which should act as a further deterrent to anyone 
contemplating making such a conversion. Together these two items 
address the agencies' primary reason for proposing the requirement that 
all vehicles with sleeper cabs be treated as tractors--the concern of 
circumvention of the tractor standards. However, the agencies will 
continue to monitor whether it appears that the definitions are 
creating unintended consequences, and may consider revising the 
definitions in a future rulemaking to address such issues should any 
arise. NHTSA and EPA have concluded that the engine and tire 
improvements required in the vocational category are appropriate for 
this set of vehicles based on the typical operation of these vehicles. 
The agencies did not intend to include vocational vehicles with sleeper 
cabs, such as an Expediter vehicle, into the tractor category in either 
the NPRM or in this final action, and the agencies' analyses at 
proposal reflected this intention. Therefore the agencies did not make 
any adjustments to the program costs and benefits due to this 
classification change.
    In response to the third comment, the agencies have decided to 
allow manufacturers to exclude certain vocational-type of tractors from 
the combination tractor standards and instead be subject to the 
vocational vehicle standards. We discuss below the reasoning underlying 
this decision, the criteria manufacturers would use in asserting a 
claim that a vocational tractor should be reclassified as a vocational 
vehicle, and the procedures the agencies will use to accept or reject 
manufacturers' claims.
    Multiple commenters (Allison Transmission, ATA, CALSTART, Eaton, 
EMA/TMA, National Solid Waste Management Association, MEMA, Navistar, 
NADA, RMA, and Volvo) argued that the agencies' proposed classification 
failed to recognize genuine differences between vocational tractors, 
which typically operate at lower speeds in stop-and-go city driving, 
and line-haul tractors, which typically operate at highway speeds on 
interstate roadways over long distances. Commenters argued that the 
proposed tractor standards and associated tractor GEM test cycles were 
derived based primarily upon the operational characteristics of the 
line-haul tractors, and that technologies that apply to these line-haul 
tractors, such as improved aerodynamics, vehicle speed limiters and 
automatic engine shutdown, as well as engine performance for improving 
emissions and fuel consumption, do not have the same positive impact on 
fuel consumption when used on tractors. In today's market, as mentioned 
by Volvo and ATA, we understand that approximately 15 percent, or 
approximately 15,000 to 20,000, of the Class 7 and 8 tractors could be 
classified as vocational tractors based upon the work they perform.
    The agencies agree that the overall operation of these vocational-
types of tractors resembles other vocational vehicles' operation: lower 
average speed and more stop and go activity than line-haul tractors. 
Due to their operation style, a FTP certified engine is a better match 
for these tractors than a SET certified engine, because the FTP cycle 
uses a lower average speed and more stop and go activity than the SET 
cycle. In addition, the limited high speed operation leads to minimal 
opportunities for fuel consumption and CO2 emissions 
reductions due to aerodynamic improvements. Conversely, the additional 
weight of the aerodynamic components could cause an unintended 
consequence of increasing gram per ton-mile emissions by reducing the 
amount of payload the vehicle can carry in those applications which are 
weight-limited. Similarly, the vocational tractors typically do not 
hotel overnight and therefore will have little to no benefit through 
the installation of an idle reduction technology.
    The agencies received several other comments that described 
criteria that could be used to distinguish between vocational and non-
vocational tractors. Volvo suggested that a tractor could be a 
vocational tractor if it meets three of five specified features:
    (1) A frame Resisting Bending Moment (RBM) greater than or equal to 
2,000,000 in-lbs per rail, or rail and liner combination;
    (2) An approach angle greater than or equal to 20 degrees nominal 
design specification, to exclude extended front rails/bumpers for 
additional equipment (e.g.--pumps, winch, front engine PTO);
    (3) Ground clearance greater than or equal to 14 inches as measured 
unladen from the lowest point of any frame rail or body mounted 
components, excluding axles and suspension (for HHD and MHD vehicles 
this is usually considered as the lowest point of the fuel tank/
mounting or chassis aerodynamic devices);
    (4) A total reduction in high gear greater than or equal to 3.00:1; 
and
    (5) A total reduction in low gear greater than or equal to 57:1.
    The approach proposed by Volvo is somewhat similar to the approach 
NHTSA has for determining if a vehicle is a light truck under the light 
vehicle CAFE program, in which a vehicle must either have a GVWR 
greater than 6,000 pounds or have 4-wheel drive, and meet

[[Page 57137]]

four of the five specified suspension characteristics (approach angle, 
break-over angle, axle clearance, etc.) to be classified as a light 
truck. Although we do not believe that the criteria suggested by Volvo 
are workable for all manufacturers and all applications, we agree that 
these criteria would reflect a reasonable basis for allowing 
manufacturers to reclassify their vehicles as vocational tractors.
    Two other commenters, EMA/TMA and Navistar, suggested simply that 
the manufacturer should have the burden of establishing that a tractor 
is a vocational tractor to the agencies' reasonable satisfaction. The 
commenters also suggested some factors that could be used to establish 
that a tractor is actually a ``vocational tractor'', including:
    (1) A vehicle speed limiter set at 55 mph or less;
    (2) Power take-off (PTO) controls;
    (3) Extended front frame;
    (4) Ground clearance greater than 14 in.;
    (5) An approach angle greater than 20 degrees;
    (6) Frame RBM greater than 2,000,000 in-lbs.; and
    (7) A total gear reduction in low gear greater than 57 and a total 
gear reduction in top gear greater than 3.
    The agencies believe that both suggested approaches have some 
merit. A rule based on specific criteria as suggested by Volvo could 
help to minimize the burden on both the manufacturers and the agencies, 
as manufacturer-written requests for approval and agency approvals of 
those requests would not be required for each vocational tractor 
determination whereas the EMA/TMA and Navistar approach requires the 
opposite namely that each manufacturer would have to justify the 
determination of each vocational tractor based upon its related design 
features in a separate petition to the agencies. Neither of the two 
approaches, which are based on specific criteria, could be used to 
identify all the tractors that should be classified as vocational 
tractors. An urban beverage delivery tractor, for example, may not be 
designed with any of the features mentioned but is used in a vocational 
vehicle manner. Also, the agencies were concerned about the possibility 
of manufacturers circumventing the system by incorporating design 
changes to their line-haul tractors in order to classify them as 
vocational tractors required to meet less stringent emission and fuel 
consumption standards. However, at this time the agencies do not 
believe that circumventing the system is likely, as most of these 
vocational tractors are built to order and will incorporate the design 
features required by the customer. Manufacturer vehicle offerings are 
designed or tailored to suit the particular task of the consumer. The 
vehicle transport mission including vehicle type, gross vehicle weight, 
gross combination weight, body style and load handling characteristics, 
must be considered in the design process. Further, how the vehicle will 
be utilized, including operating cycles, operating environment and road 
conditions, is another important consideration in designing a vehicle 
to accomplish a particular task. The agencies agree that these criteria 
could also be used as part of a basis for classification. We also note 
that many of these vehicles have front axle weight ratings greater than 
14,600 pounds.
    Although the agencies agree that these vocational tractors are 
operated differently than line-haul tractors and therefore fit more 
appropriately into the vocational vehicle category, we need to ensure 
that only tractors that are truly vocational tractors are classified as 
such. Upon further consideration of the comments received the agencies 
have decided to allow manufacturers to exclude certain vocational-type 
tractors from the combination tractor standards, and instead be subject 
to the standards for vocational vehicles. A vehicle determined by the 
manufacturer to be a HHD vocational tractor would fall into the HHD 
vocational vehicle subcategory and be regulated as a vocational 
vehicle. Similarly, MHD which the manufacturer chooses to reclassify as 
vocational tractors will be regulated as a MHD vocational vehicle. 
Specifically, under the provision being finalized at 40 CFR 1037.630 
and NHTSA's regulation at 49 CFR 523.2 of today's rules only the 
following three types of vocational tractors are eligible for 
reclassification by the manufacturer:
    (1) Low-roof tractors intended for intra-city pickup and delivery, 
such as those that deliver bottled beverages to retail stores.
    (2) Tractors intended for off-road operation (including mixed 
service operation), such as those with reinforced frames and increased 
ground clearance.
    (3) Tractors with a GCWR over 120,000 pounds.
    As adopted in 40 CFR 1037.230(a)(1)(xiii), manufacturers will be 
required to group vocational tractors into a unique family, separate 
from other combination tractors and vocational vehicles. The provision 
being adopted in 40 CFR 1037.630 and 49 CFR 535.8 requires the 
manufacturers to summarize in their applications their basis for 
believing that the vehicles are eligible for manufacturer 
reclassification as vocational tractors. EPA and NHTSA could ask for a 
more detailed description of the basis and EPA would deny an 
application for certification where it determines the manufacturer 
lacks an adequate basis for reclassification. The manufacturer would 
then have to resubmit a modified application to certify the vehicles in 
question to the tractor standards. Where we determine that a 
manufacturer is not applying this allowance in good faith, we may 
require that manufacturer to obtain preliminary approval before using 
this allowance. This would mean that a manufacturer would need to 
submit its detailed records to EPA and receive formal approval before 
submitting its application for certification. The agencies plan to 
monitor how manufacturers classify their tractor fleets and would 
reconsider the issue of vocational tractor classification in a future 
rulemaking if necessary.
    Because the difference between some vocational tractors and line-
haul tractors is potentially somewhat subjective, we are also including 
an annual sales limit of 7,000 vocational tractors per manufacturer 
(based on a three year rolling average) consistent with past production 
volumes of such vehicles. It is important to note, however, that we do 
not expect it to be common for manufacturers to be able to justify 
classifying 7,000 vehicles as vocational tractors in a given model 
year.
    Under the regulations being promulgated in 40 CFR 1037.630 and 49 
CFR 523.2, manufacturers will be required to keep records of how they 
determined that such vehicles qualify as vocational. These records 
would be more detailed than the description submitted in the 
applications. Typically, this would be a combination of records of the 
design features and/or purchasers of the vehicles. The agencies have 
analyzed the design features that reflect the special needs of these 
vocational tractors in the three areas noted above--mixed service, 
heavy haul, and urban delivery. Mixed service applications, such as 
construction trucks, typically require higher ground clearance and 
approach angle to accommodate non-paved roads. In addition, they often 
require frame rails with greater resisting bending moment (RBM) because 
of the terrain where they operate.\54\ The mixed service

[[Page 57138]]

applications also sometimes require higher front axle weight ratings to 
accommodate extra loads and/or power take off systems for additional 
capability. Heavy haul tractors are typically designed with frame rails 
with extra strength (greater RBM) and higher front axle weight ratings 
to accommodate the heavy payloads. Often the heavy haul tractors will 
also have higher ground clearance and greater approach angle for 
similar reasons as the mixed service applications. Lastly, heavy haul 
vehicles require a total gear reduction of 57:1 or greater to provide 
the torque necessary to start the vehicle moving. Urban delivery 
tractors, such as beverage haulers, have less defined design features 
that reflect their operational needs. These vehicles offer options 
which include high RBM rails and front axle weight ratings, but not all 
beverage trucks are specified with these options. The primary 
differentiation of these urban delivery tractors is their operation. 
For this final rulemaking, the agencies projected the costs and 
benefits of the program considering this provision. As detailed in RIA 
Section 5.3.2.2.1, the agencies assumed that approximately 20 percent 
of short-haul tractors sold in 2014 model year and beyond will be 
vocational tractors. As such, these vehicles will experience benefits 
reflective of a FTP-certified engine and tire rolling resistance 
improvement at the technology costs projected in the rules for 
vocational vehicles.
---------------------------------------------------------------------------

    \54\ The agencies have found based on standard truck 
specifications, that vehicles designed for significant off-road 
applications, such as concrete pumper and logging trucks have 
resisting bending moment greater than 2,100,000 lb-in. (ranging up 
to 3,580,000 lb-in.). The typical on highway tractors have resisting 
bending moment of 1,390,000 lb-in. An example line haul truck is the 
Mack Pinnacle which has a RBM of 1,390,000 lb-in, as shown at http://www.macktrucks.com/assets/MackMarketing/Specifications/CXU6124x2PinAxleBack.pdf.
---------------------------------------------------------------------------

(1) What is the form of the Class 7 and 8 tractor CO2 
emissions and fuel consumption standards?
    As proposed, EPA and NHTSA are finalizing different standards for 
different subcategories of these tractors with the basis for 
subcategorization being particular tractor attributes. Attribute-based 
standards in general recognize the variety of functions performed by 
vehicles and engines, which in turn can affect the kind of technology 
that is available to control emissions and reduce fuel consumption, or 
its effectiveness. Attributes that characterize differences in the 
design of vehicles, as well as differences in how the vehicles will be 
employed in-use, can be key factors in evaluating technological 
improvements for reducing CO2 emissions and fuel 
consumption. Developing an appropriate attribute-based standard can 
also avoid interfering with the ability of the market to offer a 
variety of products to meet consumer demand. There are several examples 
of where the agencies have utilized an attribute-based standard. In 
addition to the example of the light-duty 2012-16 MY vehicle rule, in 
which the standards are based on the attribute of vehicle 
``footprint,'' the existing heavy-duty highway engine standards for 
criteria pollutants have for many years been based on a vehicle weight 
attribute (Light Heavy, Medium Heavy, Heavy Heavy) with different 
useful life periods, which is a similar approach finalized for the 
engine GHG and fuel consumption standards discussed below.
    Heavy-duty combination tractors are built to move freight. The 
ability of a vehicle to meet a customer's freight transportation 
requirements depends on three major characteristics of the tractor: the 
gross vehicle weight rating (which along with gross combination weight 
rating (GCWR) establishes the maximum carrying capacity of the tractor 
and trailer), cab type (sleeper cabs provide overnight accommodations 
for drivers), and the tractor roof height (to mate tractors to trailers 
for the most fuel-efficient configuration). Each of these attributes 
impacts the baseline fuel consumption and GHG emissions, as well as the 
effectiveness of possible technologies, like aerodynamics, and is 
discussed in more detail below.
    The first tractor characteristic to consider is payload which is 
determined by a tractor's GVWR and GCWR relative to the weight of the 
tractor, trailer, fuel, driver, and equipment. Class 7 trucks, which 
have a GVWR of 26,001-33,000 pounds and a typical GCWR of 65,000 
pounds, have a lesser payload capacity than Class 8 trucks. Class 8 
trucks have a GVWR of greater than 33,000 pounds and a typical GCWR of 
greater than 80,000 pounds, the effective weight limit on the federal 
highway system except in states with preexisting higher weight limits. 
Consistent with the recommendation in the National Academy of Sciences 
2010 Report to NHTSA,\55\ the agencies are finalizing a load-specific 
fuel consumption metric (g/ton-mile and gal/1,000 ton-mile) where the 
``ton'' represents the amount of payload. Generally, higher payload 
capacity vehicles have better specific fuel consumption and GHG 
emissions than lower payload capacity vehicles. Therefore, since the 
amount of payload that a Class 7 vehicle can carry is less than the 
Class 8 vehicle's payload capacity, the baseline fuel consumption and 
GHG emissions performance per ton-mile differs between the categories. 
It is consequently reasonable to distinguish between these two vehicle 
categories, so that the agencies are finalizing separate standards for 
Class 7 and Class 8 tractors.
---------------------------------------------------------------------------

    \55\ See 2010 NAS Report, Note 21, Recommendation 2-1.
---------------------------------------------------------------------------

    The agencies are not finalizing a single standard for both Class 7 
and 8 tractors based on the payload carrying capabilities and assumed 
typical payload levels of Class 8 tractors alone, as that would quite 
likely have the perverse impact of increasing fuel consumption and 
greenhouse gas emissions. Such a single standard would penalize Class 7 
vehicles in favor of Class 8 vehicles. However, the greater 
capabilities of Class 8 tractors and their related greater efficiency 
when measured on a per ton-mile basis are only relevant in the context 
of operations where that greater capacity is needed. For many 
applications such as regional distribution, the trailer payloads 
dictated by the goods being carried are lower than the average Class 8 
tractor payload. In those situations, Class 7 tractors are more 
efficient than Class 8 tractors when measured by ton-mile of actual 
freight carried. This is because the extra capabilities of Class 8 
tractors add additional weight to vehicles that is only beneficial in 
the context of its higher capabilities. The existing market already 
selects for vehicle performance based on the projected payloads. By 
setting separate standards the agencies do not advantage or 
disadvantage Class 7 or 8 tractors relative to one another and continue 
to allow trucking fleets to purchase the vehicle most appropriate to 
their business practices.
    The second characteristic that affects fuel consumption and GHG 
emissions is the relationship between the tractor cab roof height and 
the type of trailer used to carry the freight. The primary trailer 
types are box, flat bed, tanker, bulk carrier, chassis, and low boys. 
Tractor manufacturers sell tractors in three roof heights--low, mid, 
and high. The manufacturers do this to obtain the best aerodynamic 
performance of a tractor-trailer combination, resulting in reductions 
of GHG emissions and fuel consumption, because it allows the frontal 
area of the tractor to be similar in size to the frontal area of the 
trailer. In other words, high roof tractors are designed to be paired 
with a (relatively tall) box trailer while a low roof tractor is 
designed to pull a (relatively low) flat bed trailer. The baseline 
performance of

[[Page 57139]]

a high roof, mid roof, and low roof tractor differs due to the 
variation in frontal area which determines the aerodynamic drag. For 
example, the frontal area of a low roof tractor is approximately 6 
square meters, while a high roof tractor has a frontal area of 
approximately 9.8 square meters. Therefore, as explained below, the 
agencies are using the roof height of the tractor to determine the 
trailer type required to be used to demonstrate compliance of a vehicle 
with the fuel consumption and CO2 emissions standards. As 
with vehicle weight classes, setting separate standards for each 
tractor roof height helps ensure that all tractors are regulated to 
achieve appropriate improvements, without inadvertently leading to 
increased emissions and fuel consumption by shifting the mix of vehicle 
roof heights offered in the market away from a level determined by 
market foces linked to the actual trailers vehicles will haul in-use.
    Tractor cabs typically can be divided into two configurations--day 
cabs and sleeper cabs. Line haul operations typically require overnight 
accommodations due to Federal Motor Carrier Safety Administration hours 
of operation requirements.\56\ Therefore, some truck buyers purchase 
tractor cabs with sleeping accommodations, also known as sleeper cabs, 
because they do not return to their home base nightly. Sleeper cabs 
tend to have a greater empty curb weight than day cabs due to the 
larger cab volume and accommodations, which lead to a higher baseline 
fuel consumption for sleeper cabs when compared to day cabs. In 
addition, there are specific technologies, such as extended idle 
reduction technologies, which are appropriate only for tractors which 
hotel--such as sleeper cabs. To respect these differences, the agencies 
are finalizing separate standards for sleeper cabs and day cabs.\57\
---------------------------------------------------------------------------

    \56\ The Federal Motor Carrier Safety Administration's Hours-of-
Service regulations put limits in place for when and how long 
commercial motor vehicle drivers may drive. They are based on an 
exhaustive scientific review and are designed to ensure truck 
drivers get the necessary rest to perform safe operations. See 49 
CFR part 395, and see also http://www.fmcsa.dot.gov/rules-regulations/topics/hos/index.htm (last accessed August 8, 2010).
    \57\ The agencies note, as discussed in the previous section, 
that some day cabs and sleeper cabs will be reclassified as 
vocational tractors and if so will not be subject to the combination 
tractor standards.
---------------------------------------------------------------------------

    The agencies received comments from industry stakeholders (EMA, 
Allison Transmission, Bosch, and the Heavy-Duty Fuel Efficiency 
Leadership Group) and ICCT supporting the nine tractor regulatory 
subcategories proposed and did not receive any comments which supported 
an alternate classification. Thus, to account for the relevant 
combinations of these attributes, the agencies are adopting the 
classification scheme proposed, segmenting combination tractors into 
the following nine regulatory subcategories:
     Class 7 Day Cab With Low Roof
     Class 7 Day Cab With Mid Roof
     Class 7 Day Cab With High Roof
     Class 8 Day Cab With Low Roof
     Class 8 Day Cab With Mid Roof
     Class 8 Day Cab With High Roof
     Class 8 Sleeper Cab With Low Roof
     Class 8 Sleeper Cab With Mid Roof
     Class 8 Sleeper Cab With High Roof
    Adjustable roof fairings are used today on what the agencies 
consider to be low roof tractors. The adjustable fairings allow the 
operator to change the fairing height to better match the type of 
trailer that is being pulled which can reduce fuel consumption and GHG 
emissions during operation. As proposed, the agencies are treating 
tractors with adjustable roof fairings as low roof tractors that will 
tested with the fairing in its lowest position.
(2) What are the Final Class 7 and 8 Tractor and Engine CO2 
Emissions and Fuel Consumption Standards and Their Timing?
    In developing the final standards for Class 7 and 8 tractors and 
for the engines used in these tractors, the agencies have evaluated the 
current levels of emissions and fuel consumption, the kinds of 
technologies that could be utilized by truck and engine manufacturers 
to reduce emissions and fuel consumption from tractors and associated 
engines, the necessary lead time, the associated costs for the 
industry, fuel savings for the consumer, and the magnitude of the 
CO2 and fuel savings that may be achieved. The technologies 
on whose performance the final tractor standards are predicated are 
improvements in aerodynamic design, lower rolling resistance tires, 
extended idle reduction technologies, and lightweighting of the 
tractor. The technologies on whose performance the final tractor 
standards are predicated are engine friction reduction, aftertreatment 
optimization, and turbocompounding, among others, as described in RIA 
Chapter 2.4. The agencies' evaluation showed that these technologies 
are available today, but have very low application rates on current 
vehicles and engines. EPA and NHTSA also present the estimated costs 
and benefits of the Class 7 and 8 combination tractor and engine 
standards in Section III and in RIA Chapter 2, explaining as well the 
basis for the agencies' conclusion not to adopt standards which are 
less stringent or more stringent.
(a) Tractor Standards
    The agencies are finalizing the following standards for Class 7 and 
8 combination tractors in Table 0-1, using the subcategorization 
approach that was proposed. As explained below in Section III, EPA has 
determined that there is sufficient lead time to introduce various 
tractor and engine technologies into the fleet starting in the 2014 
model year, and is finalizing standards starting for that model year 
predicated on performance of those technologies. EPA is finalizing more 
stringent tractor standards for the 2017 model year which reflect the 
CO2 emissions reductions required for 2017 model year 
engines. (As explained in Section II.B(3)(h)(v) below, engine 
performance is one of the inputs into the compliance model, and that 
input will change in 2017 to reflect the 2017 MY engine standards.) The 
2017 MY vehicle standards are not premised on tractor manufacturers 
installing additional vehicle technologies. EPA's final standards apply 
throughout the useful life period as described in Section V. As 
proposed, and as discussed further in Section IV below, manufacturers 
may generate and use credits from Class 7 and 8 combination tractors to 
show compliance with the standards.
    NHTSA is finalizing Class 7 and 8 tractor fuel consumption 
standards that are voluntary standards in the 2014 and 2015 model years 
and become mandatory beginning in the 2016 model year, as required by 
the lead time within EISA. The 2014 and 2015 model year standards are 
voluntary in that manufacturers are not subject to them unless they 
opt-in to the standards.\58\ Manufacturers that opt in become subject 
to NHTSA standards for all regulatory categories. NHTSA is also 
adopting new tractor standards for the 2017 model year which reflect 
additional improvements in only the heavy-duty engines. As proposed, 
NHTSA is not implementing an in-use compliance program for fuel 
consumption because it does not anticipate that there will be notable 
deterioration of fuel consumption over the useful life of the vehicle.
---------------------------------------------------------------------------

    \58\ Once a manufacturer opts into the NHTSA program it must 
stay in the program for all the optional MYs.
---------------------------------------------------------------------------

    As explained more fully in Section III and Chapter 2 of the RIA, 
EPA and NHTSA are not adopting more stringent tractor standards for 
2014-2017 MY. The final tractor standards are based on

[[Page 57140]]

the maximum application rates of available technologies considering the 
available lead time, and we explain in Section III and Chapter 2 of the 
RIA that use of additional technologies, or further application of the 
technologies already mentioned would be either infeasible in the lead 
time afforded, or uneconomic.

               Table II-1--Heavy-Duty Combination Tractor Emissions and Fuel Consumption Standards
----------------------------------------------------------------------------------------------------------------
                                                                      Day cab                     Sleeper cab
                                                     -----------------------------------------------------------
                                                            Class 7             Class 8             Class 8
----------------------------------------------------------------------------------------------------------------
                                     2014 Model Year CO2 Grams per Ton-Mile
----------------------------------------------------------------------------------------------------------------
Low Roof............................................                 107                  81                  68
Mid Roof............................................                 119                  88                  76
High Roof...........................................                 124                  92                  75
----------------------------------------------------------------------------------------------------------------
                          2014-2016 Model Year Gallons of Fuel per 1,000 Ton-Mile \59\
----------------------------------------------------------------------------------------------------------------
Low Roof............................................                10.5                 8.0                 6.7
Mid Roof............................................                11.7                 8.7                 7.4
High Roof...........................................                12.2                 9.0                 7.3
----------------------------------------------------------------------------------------------------------------
                                     2017 Model Year CO2 Grams per Ton-Mile
----------------------------------------------------------------------------------------------------------------
Low Roof............................................                 104                  80                  66
Mid Roof............................................                 115                  86                  73
High Roof...........................................                 120                  89                  72
----------------------------------------------------------------------------------------------------------------
                          2017 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile
----------------------------------------------------------------------------------------------------------------
Low Roof............................................                10.2                 7.8                 6.5
Mid Roof............................................                11.3                 8.4                 7.2
High Roof...........................................                11.8                 8.7                 7.1
----------------------------------------------------------------------------------------------------------------

    The standard values shown above differ somewhat from the proposal, 
reflecting refinements made to the GEM in response to comments. For 
example, the agencies received comments from stakeholders concerned 
that the 2017 MY tractor standards appeared to be backsliding because 
the reductions were not in line with the reductions expected from the 
2017 MY engine standards. The agencies reviewed the issue and found 
that the engine maps we created in the GEM for the 2017 model year for 
the proposal did not appropriately reflect the engine improvements. 
Therefore, the agencies developed new fuel maps for the GEM v2.0 which 
fully reflect the engine improvements due to the 2017 MY standards.\60\ 
These changes to the GEM did not impact our estimates of the relative 
effectiveness of the greenhouse gas emissions and fuel consumption 
improving technologies modeled in this final action nor the overall 
cost or benefits estimated for these final vehicle standards.
---------------------------------------------------------------------------

    \59\ As noted above, manufacturers may voluntarily opt-in to the 
NHTSA fuel consumption program in 2014 or 2015. Once a manufacturer 
opts into the NHTSA program it must stay in the program for all the 
optional MYs.
    \60\ See RIA Chapter 4 for the engine fuel maps used in GEM 
v2.0.
---------------------------------------------------------------------------

    Based on our analysis, the 2017 model year standards for 
combination tractors and engines represent up to a 23 percent reduction 
in CO2 emissions and fuel consumption over a 2010 model year 
baseline tractor (the baseline sleeper cab does not include idle 
shutdown technology), as detailed in Section III.A.2. In considering 
the feasibility of vehicles to comply with the standards, EPA also 
considered the potential for CO2 emissions to increase 
during the regulatory useful life of the product. As we discuss 
separately in the context of deterioration factor (DF) testing, we have 
concluded that CO2 emissions are likely to stay the same or 
actually decrease in-use compared to new certified configurations. In 
general, engine and vehicle friction decreases as products wear in 
leading to reduced parasitic losses and lower CO2 emissions. 
Similarly, tire rolling resistance falls as tires wear due to the 
reduction in tread height. In the case of aerodynamic components, we 
project no change in performance through the regulatory life of the 
vehicle since there is essentially no change in their physical form as 
vehicles age. Similarly, weight reduction elements such as aluminum 
wheels are not projected to increase in mass through time, and hence, 
we can conclude will not deteriorate with regard to CO2 
performance in-use. Given all of these considerations, EPA is confident 
in projecting that the standards finalized today will be technical 
feasible throughout the regulatory useful life of the program.
(b) Standards for Engines Installed in Combination Tractors
    EPA is adopting GHG standards and NHTSA is adopting fuel 
consumption standards for new heavy-duty engines. This section 
discusses the standards for engines used in Class 7 and 8 combination 
tractors and also provides some overall background information. We also 
note that the agencies are adopting standards for heavy-duty engines 
used in vocational vehicles. However, as explained further below, 
compliance with the standards would be measured using different test 
procedures, corresponding with actual vehicle use, depending on whether 
the vehicle in which the engine is installed is a Class 7 and 8 
combination tractor or a vocational vehicle.
    The heavy-duty engine standards vary depending on the type of 
vehicle in which they are installed, as well as whether the engines are 
compression ignition or spark ignition. The agencies are adopting 
separate engine fuel consumption and GHG emissions standards for 
engines installed in combination tractors versus engines installed in 
vocational vehicles. Also, for the purposes of the GHG engine emissions 
and engine fuel consumption standards, the agencies are adopting engine 
subcategories that match EPA's

[[Page 57141]]

existing criteria pollutant emissions regulations for heavy-duty 
highway engines which established four regulatory service classes that 
represent the engine's intended and primary vehicle application.\61\ 
The Light Heavy-Duty (LHD) diesel engines are intended for application 
in Class 2b through Class 5 trucks (8,501 through 19,500 pounds GVWR). 
The Medium Heavy-Duty (MHD) diesel engines are intended for Class 6 and 
Class 7 trucks (19,501 through 33,000 pounds GVWR). The Heavy Heavy-
Duty (HDD) diesel engines are primarily used in Class 8 trucks (33,001 
pounds and greater GVWR). Lastly, spark ignition engines (primarily 
gasoline-powered engines) installed in incomplete vehicles less than 
14,000 pounds GVWR and spark ignition engines that are installed in all 
vehicles (complete or incomplete) greater than 14,000 pounds GVWR are 
grouped into a single engine service class. The engines in these four 
regulatory service classes range in size between approximately five 
liters and sixteen liters. This subcategory structure enables the 
agencies to set standards that appropriately reflect the technology 
available for engines installed in each type of vehicle, and that are 
therefore technologically feasible for these engines. This is the same 
engine classification scheme the agencies proposed, and there were no 
adverse comments in response to the proposal.
---------------------------------------------------------------------------

    \61\ See 40 CFR 86.90-2.
---------------------------------------------------------------------------

    Heavy heavy-duty diesel and medium heavy-duty diesel engines are 
used today in combination tractors. The following section refers to the 
engine standards for these types of engines. This section does not 
cover gasoline or light heavy-duty diesel engines because they are not 
used in combination tractors.
    In the NPRM, the agencies proposed CO2 and fuel 
consumption standards for HD diesel engines to be installed in Class 7 
and 8 combination tractors as shown in Table II-2.\62\
---------------------------------------------------------------------------

    \62\ The agencies note that the CO2 and fuel 
consumption standards for Class 7 and 8 combination tractors do not 
cover gasoline or LHDD engines, as those are not used in Class 7 and 
8 combination tractors.

            Table II-2--Proposed Heavy-duty Diesel Engine Standards for Engines Installed in Tractors
----------------------------------------------------------------------------------------------------------------
                                                     Effective 2014 model year       Effective 2017 Model Year
                                                 ---------------------------------------------------------------
                                                                  Voluntary fuel                       Fuel
                                                   CO2 standard     consumption    CO2 standard     consumption
                                                    (g/bhp-hr)    standard  (gal/   (g/bhp-hr)    standard  (gal/
                                                                    100 bhp-hr)                     100 bhp-hr)
----------------------------------------------------------------------------------------------------------------
MHD diesel engine...............................             502            4.93             487            4.78
HHD diesel engine...............................             475            4.67             460            4.52
----------------------------------------------------------------------------------------------------------------

    The agencies proposed to require diesel engine manufacturers to 
achieve, on average, a three percent reduction in fuel consumption and 
CO2 emissions for the 2014 standards over the baseline MY 
2010 performance for the engines.\63\ The agencies' preliminary 
assessment of the findings of the 2010 NAS Report and other literature 
sources indicated that there are technologies available to reduce fuel 
consumption by this amount in the time frame in the lead time provided 
by the rules. These technologies include improved turbochargers, 
aftertreatment optimization, and low temperature exhaust gas 
recirculation.
---------------------------------------------------------------------------

    \63\ The baseline HHD diesel engine performance in MY 2010 on 
the SET is 490 g CO2/bhp-hr (4.81 gal/100 bhp-hr), as 
determined from confidential data provided by manufacturers and data 
submitted for the non-GHG emissions certification process. The 
baseline MHD diesel engine performance on the SET cycle is 518 g 
CO2/bhp-hr (5.09 gallon/100-bhp-hr) in MY 2010. Further 
discussion of the derivation of the baseline can be found in Section 
III.
---------------------------------------------------------------------------

    The agencies also proposed to require diesel engine manufacturers 
to achieve, on average, a six percent reduction in fuel consumption and 
CO2 emissions for the 2017 MY standards over the baseline MY 
2010 performance for MHD and HHD diesel engines required to use the 
SET-based standard. The agencies stated that additional reductions 
could likely be achieved through the increased refinement of the 
technologies projected to be implemented for 2014, plus the addition of 
turbocompounding, which the agencies' analysis showed would require a 
longer development time and would not be available in MY 2014. The 
agencies therefore proposed to provide additional lead time to allow 
for the introduction of this additional technology, and to wait until 
2017 to increase stringency to levels reflecting application of this 
technology.
    The agencies proposed that the MHD and HHD diesel engine 
CO2 standards for Class 7 and 8 combination tractors would 
become effective in MY 2014 for EPA, with more stringent CO2 
standards becoming effective in MY 2017, while NHTSA's fuel consumption 
standards would become effective in MY 2017, which would be both 
consistent with the EISA four-year minimum lead-time requirements and 
harmonized with EPA's timing. The agencies explained that the three-
year timing, besides being required by EISA, made sense because EPA's 
heavy-duty highway engine program for criteria pollutants had begun to 
provide new emissions standards for the industry in three year 
increments, which had caused the heavy-duty engine product plans to 
fall largely into three year cycles reflecting this regulatory 
environment. To further harmonize with EPA, NHTSA proposed voluntary 
fuel consumption standards for MHD and HHD diesel engines that are 
equivalent to EPA CO2 standards for MYs 2014-2016, allowing 
manufacturers to opt into the voluntary standards in any of those model 
years.\64\ NHTSA proposed that manufacturers could opt into the program 
by declaring their intent to opt in to the program at the same time 
they submit the Pre-Certification Compliance Report, and that a 
manufacturer opting into the program would begin tracking credits and 
debits beginning in the model year in which they opt into the program. 
Both agencies proposed to allow manufacturers to generate and use 
credits to achieve compliance with the HD diesel engine standards, 
including averaging, banking, and trading (ABT) and deficit carry-
forward. The agencies sought comment on the proposed MHD and HHD engine 
standards and timing.
---------------------------------------------------------------------------

    \64\ Once a manufacturer opts into the NHTSA program it must 
stay in the program for all the optional MYs and remain standardized 
with the implementation approach being used to meet the EPA emission 
program.
---------------------------------------------------------------------------

    The agencies received comments from EMA, Navistar, Cummins, ACEEE, 
Center for Biological Diversity, Detroit Diesel Corporation, American 
Lung Association, and the Union of

[[Page 57142]]

Concerned Scientists. Comments were divided with respect to the 
proposed levels of stringency. While Cummins and DDC expressed support 
for the CO2 and fuel consumption standards for diesel 
engines, and EMA and Navistar stated the standards could be met if the 
flexibilities outlined in the NPRM are finalized as proposed, Navistar 
also stated that the model year 2017 standard may not be feasible since 
what the agencies characterized as existing technologies are not in 
production for all manufacturers. In contrast, environmental groups and 
NGOs stated that the standards did not reflect the potential reductions 
outlined in the 2010 NAS study and should be more stringent. CBD argued 
that the standards were not set at the maximum feasible level by 
definition, because the agencies had said that they were based on the 
use of existing technologies. In addition, the Center for Neighborhood 
Technology encouraged the agencies to implement the rules as soon as 
possible, beginning in the 2012 model year.
    In light of the above comments, the agencies re-evaluated the 
technical basis for the heavy-duty engine standards. The baseline HHD 
diesel engine performance in 2010 model year on the SET is estimated at 
490 g CO2/bhp-hr (4.81 gal/100 bhp-hr), based on our 
analysis of confidential data provided by manufacturers and data 
submitted for the non-GHG emissions certification process. Similarly, 
the baseline MHD diesel engine performance on the SET cycle is 
estimated to be 518 g CO2/bhp-hr (5.09 gallon/100-bhp-hr) 
for the 2010 model year. Further discussion of the derivation of the 
baseline can be found in Section III. The agencies believe that the MY 
2014 standards can be achieved by most manufacturers through the use of 
technologies time frame such as improved aftertreatment systems, 
friction reduction, improved auxiliaries, turbochargers, pistons, and 
other components. These standards will require diesel engine 
manufacturers to achieve on average a three percent reduction in fuel 
consumption and CO2 emissions over the baseline 2010 model 
year levels.
    However, in recognizing that some manufacturers have engines that 
would not meet the standard even after applying technologies that 
improve GHG emissions and fuel consumption by three percent, the 
agencies are finalizing both the proposed ABT provisions for these 
engines and also an optional alternate engine standard for 2014 model 
year, described in more detail below. We believe that concerns 
expressed by Navistar regarding the 2014 MY standards will be addressed 
by this alternative standard. The agencies also continue to believe 
that the 2017 MY standards are achievable using the above approaches 
and, in the case of SET certified engines, turbocompounding. While 
Navistar commented that the 2017 MY standard may be challenging because 
not all manufacturers are presently producing the technologies that may 
be required to meet the standards, the agencies believe that since 
manufacturers that may require turbocompounding to meet the standards 
will not have to do so until 2017 MY, there will be sufficient lead 
time for all manufacturers to introduce this technology. As noted 
above, by MY 2017 all MHD and HHD engines installed in combination 
tractors should have gone through a redesign during which all needed 
technology can be applied. We note that we are finalizing these 
standards as proposed based on the assessment that most manufacturers 
(not just Navistar) will need to make improvements to existing engine 
systems in order to meet the standards. EPA's HD diesel engine 
CO2 emission standards and NHTSA's HD diesel engine fuel 
consumption standards for engines installed in tractors are presented 
in Table II-3. As explained above, the first set of standards take 
effect with MY 2014 (mandatory standards for EPA, voluntary standards 
for NHTSA), and the second set take effect with MY 2017 (mandatory for 
both agencies).

             Table II-3--Final Heavy-duty Diesel Engine Standards for Engines Installed in Tractors
----------------------------------------------------------------------------------------------------------------
                                                     Effective 2014 model year       Effective 2017 model year
                                                 ---------------------------------------------------------------
                                                                  Voluntary fuel                       Fuel
                                                   CO2 standard     consumption    CO2 standard     consumption
                                                    (g/bhp-hr)    standard  (gal/   (g/bhp-hr)    standard  (gal/
                                                                    100 bhp-hr)                     100 bhp-hr)
----------------------------------------------------------------------------------------------------------------
MHD diesel engine...............................             502            4.93             487            4.78
HHD diesel engine...............................             475            4.67             460            4.52
----------------------------------------------------------------------------------------------------------------

    The agencies have also decided to remove NHTSA's proposed Pre-
Certification Compliance Report requirement. Instead, manufacturers 
must submit their decision to opt into NHTSA's voluntary standards for 
the 2014 through 2016 model years as part of its certification process 
with EPA. Once a manufacturer opts into the NHTSA program it must stay 
in the program for all the subsequent optional model years. 
Manufacturers that opt in become subject to NHTSA standards for all 
regulatory categories. The declaration statement must be entered prior 
to or at the same time the manufacturer submits its first application 
for a certificate of conformity. NHTSA will begin tracking credits and 
debits beginning in the model year in which a manufacturer opts into 
its program.
    Compliance with the CO2 emissions and fuel consumption 
standards will be evaluated based on the SET engine test cycle. In the 
NPRM, the agencies proposed standards based on the SET cycle for MHD 
and HHD engines used in tractors due to these engines' primary use in 
steady state operating conditions (typified by highway cruising). 
Tractors spend the majority of their operation at steady state 
conditions, and will obtain in-use benefit of technologies such as 
turbocompounding and other waste heat recovery technologies during this 
kind of typical engine operation. Therefore, the engines installed in 
tractors will be required to meet the standard based on the SET, which 
is a steady state test cycle.
    The agencies gave full consideration to the need for engine 
manufacturers to redesign and upgrade their engines during the MYs 
2014-2017 to meet standards, and fully considered the cost-
effectiveness of the standards and the available lead time. The final 
two-step CO2 emission and fuel consumption standards 
recognize the opportunity for technology improvements over the 
rulemaking time frame, while reflecting the typical engine 
manufacturers' product plan cycles. Over these four model years there 
will be an opportunity for manufacturers to evaluate almost every one 
of their

[[Page 57143]]

engine models and add technology in a cost-effective way, consistent 
with existing redesign schedules, to control GHG emissions and reduce 
fuel consumption. The time-frame and levels for the standards, as well 
as the ability to average, bank and trade credits and carry a deficit 
forward for a limited time, are expected to provide manufacturers the 
time and flexibilities needed to incorporate technology that will 
achieve the final GHG and fuel consumption standards within the normal 
engine redesign process. This is an important aspect of the final 
rules, as it will avoid the much higher costs that would occur if 
manufacturers needed to add or change technology at times other than 
these scheduled redesigns.\65\ This time period will also provide 
manufacturers the opportunity to plan for compliance using a multi-year 
time frame, again in alignment with their normal business practice. 
Further details on lead time, redesigns and technical feasibility can 
be found in Section III.
---------------------------------------------------------------------------

    \65\ See 75 FR at 25467-68 for further discussion of the 
negative cost implications of establishing requirements outside of 
the redesign cycle.
---------------------------------------------------------------------------

    The agencies continue to believe the standards for MHD and HHD 
diesel engines installed in combination tractors are the most stringent 
technically feasible in the time frame established in this regulation. 
The standards will require a 3 percent reduction in engine fuel 
consumption and GHG emissions in 2014 MY based on improvements to 
engine components and aftertreatment systems. The 2017 MY standards 
will require a 6 percent reduction in fuel consumption and GHG 
emissions over a 2010 model year baseline and assumes the introduction, 
for some engines, of technologies such as turbocompounding. The 
standards, however, are not premised on the introduction of 
technologies that are still in development--such as Rankine bottoming 
cycle--since these approaches cannot be introduced without further 
technical development or engine re-design.\66\
---------------------------------------------------------------------------

    \66\ See RIA Chapter 2.4.2.7.
---------------------------------------------------------------------------

    Additional discussion on technical feasibility is included in 
Section III below and in Chapter 2 of the RIA.
    The agencies recognize, however, that the schedule of changes for 
the final standards may not be the most cost-effective one for all 
manufacturers. The agencies also sought comment as to whether an 
alternate phase-in schedule for the HD diesel engine standards for 
combination tractors should be considered. In developing the proposal, 
heavy-duty engine manufacturers stated that the phase-in of the GHG and 
fuel consumption standards should be aligned with the On Board 
Diagnostic (OBD)\67\ phase-in schedule, which includes new requirements 
for heavy-duty vehicles in the 2013 and 2016 model years. The agencies 
did not adopt this suggestion in the proposal, explaining that the 
credit averaging, banking and trading provisions would provide 
manufacturers with considerable flexibility to manage their GHG and 
fuel efficiency standard compliance plans--including the phase-in of 
the new heavy-duty OBD requirements--but requested comment on whether 
EPA and NHTSA should provide an alternate phase-in schedules that would 
more explicitly accommodate this request in the event that 
manufacturers did not agree that the ABT provisions mitigated their 
concern about the GHG/fuel consumption standard phase-in. See 75 FR at 
74178.
---------------------------------------------------------------------------

    \67\ On-board diagnostics (OBD) is a computer-based emissions 
monitoring system that was first required in 2007 for vehicles under 
14,000 pounds (65 FR 59896, Oct. 6, 2000) and in 2010 for vehicles 
over 14,000 pounds (74 FR 8310, Feb. 24, 2009).
---------------------------------------------------------------------------

    In response, Cummins, Engine Manufacturers Association, and DTNA 
commented that their first choice was a delay in the OBD effective date 
for one year to the 2014 model year. The industry's second choice was 
to provide manufacturers with an optional GHG and fuel consumption 
phase-in that aligns their product development plans with their current 
plans to meet the OBD regulations for EPA and California in the 2013 
and 2016 model years. These commenters argued that meeting the OBD 
regulation in the 2013 model year already poses a significant 
challenge, and that having to meet GHG and fuel consumption standards 
beginning in 2014 could require them to redesign and recertify their 
products just one year later. They argued that bundling design changes 
where possible can reduce the burden on industry for complying with 
regulations, so aligning the introduction of the OBD, GHG, and fuel 
consumption standards could help reduce manufacturers' burden for 
product development, validation and certification.
    In order to provide additional flexibility for manufacturers 
looking to align their technology changes with multiple regulatory 
requirements, the agencies are finalizing an alternate ``OBD phase-in'' 
option for meeting the standards for MHD and HHD diesel engines 
installed in tractors (in addition to engines installed in vocational 
vehicles as noted below in Section II.D), which delivers equivalent 
CO2 emissions and fuel consumption reductions as the primary 
standards for the engines built in the 2013 through 2017 model years, 
as shown in Table II-4. The optional OBD phase-in schedule requires 
that engines built in the 2013 and 2016 model years to achieve greater 
reductions than the engines built in those model years under the 
primary program, but requires fewer reductions for the engines built in 
the 2014 and 2015 model years.

 Table II-4--Comparison of CO2 reductions for the HHD and MHD Tractor Standards Under the Alternative OBD Phase-
                                             In and Primary Phase-In
----------------------------------------------------------------------------------------------------------------
                                             HHD Tractor engines                    MHD Tractor engines
                                   -----------------------------------------------------------------------------
                                                               Difference                             Difference
                                      Primary      Optional   in lifetime    Primary      Optional   in lifetime
                                      phase-in     phase-in    CO2 engine    phase-in     phase-in    CO2 engine
                                      standard     standard    emissions     standard     standard    emissions
                                     (g/bhp-hr)   (g/bhp-hr)     (MMT)      (g/bhp-hr)   (g/bhp-hr)     (MMT)
----------------------------------------------------------------------------------------------------------------
Baseline..........................          490          490           --          518          518           --
2013 MY Engine....................          490          485           14          518          512           17
2014 MY Engine....................          475          485          -28          502          512          -28
2015 MY Engine....................          475          485          -28          502          512          -28
2016 MY Engine....................          475          460           42          502          487           42
2017 MY Engine....................          460          460            0          487          487            0
Net Reductions (MMT)..............  ...........  ...........            0  ...........  ...........            3
----------------------------------------------------------------------------------------------------------------


[[Page 57144]]

    The technologies for the 2013 model year optional standard include 
a subset of technologies that could be used to meet the primary 2014 
model year standard. The agencies believe this approach is appropriate 
because the shorter lead time provided for manufacturers selecting this 
option limits the technologies which can be applied. However, in order 
to maintain equivalent CO2 emissions and fuel consumption 
reduction over the 2013 through 2017 model year period, it is necessary 
for the 2016 model year standard to be equal to the 2017 model year 
standard, using the same technology paths described for the primary 
engine program. If a manufacturer selects this optional phase-in, then 
the engines must be certified starting in the 2013 model year and 
continue using this phase-in through 2016 model year. That is, once 
electing this compliance path, manufacturers must adhere to it.\68\ 
Manufacturers may opt into the optional OBD phase-in through the 
voluntary NHTSA program, but must opt in in the 2013 model year and 
continue using this phase-in through the 2016 model year. Manufacturers 
that opt in to the voluntary NHTSA program in 2014 and 2015 will be 
required to meet the primary phase-in schedule and may not adopt the 
OBD phase-in option. Table II-5 below presents the final HD diesel 
engine CO2 emission standards under the ``OBD phase-in'' 
option.
---------------------------------------------------------------------------

    \68\ See Sec.  1036.150(e).

  Table II-5--Optional Heavy-Duty Engine Standard Phase-in Schedule for
                             Tractor Engines
------------------------------------------------------------------------
                                   MHD Diesel engine   HHD Diesel engine
------------------------------------------------------------------------
                 Effective 2013 Through 2015 Model Year
------------------------------------------------------------------------
CO2 Standard (g/bhp-hr).........                 512                 485
Voluntary Fuel Consumption                      5.03                4.76
 Standard (gallon/100 bhp-hr)...
------------------------------------------------------------------------
                   Effective 2016 Model Year and Later
------------------------------------------------------------------------
CO2 Standard (g/bhp-hr).........                 487                 460
Fuel Consumption (gallon/100 bhp-               4.78                4.52
 hr)............................
------------------------------------------------------------------------

    Although the agencies believe that the standards for the HD diesel 
engines installed in combination tractors are generally appropriate, 
cost-effective, and technologically feasible in the rulemaking time 
frame, we also recognize that when regulating a category of engines for 
the first time, there will be individual products that may deviate 
significantly from the baseline level of performance, whether because 
of a specific approach to criteria pollution control, or due to engine 
calibration for specific applications or duty cycles. In the current 
fleet of 2010 and 2011 model year engines used in combination tractors, 
NHTSA and EPA understand that there is a relatively small group of 
legacy engines that are up to approximately 25 percent worse than the 
average baseline for other engines. For this group of legacy MHD and 
HHD diesel engines installed in tractors, when compared to the typical 
performance levels of the majority of the engines in the fleet and the 
fuel consumption/GHG emissions reductions that the majority of engines 
would achieve through increased application of technology, the same 
reduction from the industry baseline may not be possible at reasonably 
comparable cost given the same amount of lead-time, because these 
products may require a total redesign in order to meet the standards. 
Manufacturers of the MHD and HHD diesel engines installed in tractors 
with atypically high baseline CO2 and fuel consumption 
levels may also, in some instances, have a limited line of engines 
across which to average performance to meet the generally-applicable 
standards.
    To account for this possibility, the agencies requested comment in 
the NPRM on the establishment of an optional alternative MHD and HHD 
engine standard for those engines installed in combination tractors 
which would be set at 3 percent below a manufacturer's 2011 engine 
baseline emissions and fuel consumption, or alternatively, at 2 percent 
below a manufacturer's 2011 baseline. The agencies also requested 
comment on extending this optional standard one year (to the 2017 MY) 
for a single engine family at a 6 percent level below the 2011 
baseline.\69\ This option would not be available unless and until a 
manufacturer had exhausted all available credits and credit 
opportunities, and engines under the optional standard could not 
generate credits.
---------------------------------------------------------------------------

    \69\ See 75 FR at 74178-74179.
---------------------------------------------------------------------------

    In comments to the NPRM, Navistar supported the alternative engine 
standard, but recommended that it be set at 2 percent below the 
manufacturer's 2011 baseline. They also supported the extension to 2017 
MY at 6 percent. Navistar provided CBI in support of its comments. 
Volvo, DTNA, environmental groups, NGOs, and the New York State 
Department of Environmental Conservation opposed the optional engine 
standard, arguing that existing flexibilities are sufficient to allow 
compliance with the standards and that all manufacturers should be held 
to the same standards.
    Based on the CBI submitted by Navistar, the agencies found that a 
large majority of the HD diesel engines used in Class 7 and 8 
combination tractors were relatively close to the average baseline, 
with some above and some below, but also that some legacy MHD and HDD 
diesel engines were far enough away from the baseline that they could 
not meet the generally-applicable standards with application of 
technology that would be available for those specific engines by 2014. 
The agencies continue to believe that an interim alternative standard 
is needed for these products, and that an interim standard reflects a 
legitimate difference between products starting from different fuel 
consumption/GHG emitting baselines. As explained in the proposal, it is 
legally permissible to accommodate short term lead time constraints 
with alternative standards. Commenters did not dispute that there are 
legacy engine families with significantly higher CO2 
emissions and fuel consumption baselines, and that these engines 
require longer lead time to meet the principal standards in the early 
model years of the program. Although the agencies acknowledge the view 
that all manufacturers should be subject to the same burden for meeting 
the primary standards, the agencies believe that, in the initial years 
of a new program,

[[Page 57145]]

additional flexibilities should be provided. The GHG standards and fuel 
consumption standards are first-time standards for these engines, so 
the possibility of significantly different baselines is not 
unexpected.\70\ Moreover, the agencies do not believe that the 
alternative standard affords a relative competitive advantage to the 
higher emitting legacy engines: the same level of improvement at the 
same cost will be required of those tractor engines, and in addition, 
by 2017 MY, those tractor engines will be required to make the 
additional improvements to meet the same standards as other engines. We 
believe that the concern expressed by Navistar regarding the 2014 MY 
standards will be addressed by this alternative. The agencies also 
continue to believe the 2017 MY standards are achievable using the 
above approaches and, in the case of MHD and HHD engines installed in 
tractors, turbocompounding. While Navistar commented that the 2017 MY 
standard may be challenging, the agencies believe that since 
manufacturers which may need to use turbocompounding to meet the 
standards will not have to do so until 2017 MY, there will be 
sufficient lead time for all engine manufacturers to introduce this 
technology. Thus, the agencies are finalizing a regulatory alternative 
whereby a manufacturer, for an interim period of the 2014-2016 model 
years, would have the option to comply with a unique standard based on 
a three percent reduction from an individual engine's own 2011 model 
year baseline level. Our assessment is that this three percent 
reduction is appropriate given the potential for manufacturers to apply 
similar technology packages with similar cost to what we have estimated 
for the primary program. This is similar to EPA's approach in the 
light-duty rule for handling a certain subset of vehicles that were 
deemed unable to meet the generally-applicable GHG standards during the 
2012-2015 time frame due to higher initial baseline conditions, and 
which therefore needed alternate standards in those model years.\71\
---------------------------------------------------------------------------

    \70\ See 75 FR at 74178.
    \71\ See 75 FR 25414-25419.
---------------------------------------------------------------------------

    The agencies stress that this is a temporary and limited option 
being implemented to address diverse manufacturer needs associated with 
complying with this first phase of the regulations. As codified in 40 
CFR 1036.620 and 49 CFR 535.5(d), this optional standard will be 
available only for the 2014 through 2016 model years, because we 
believe that manufacturers will have had ample opportunity to make 
appropriate changes to bring their product performance into line with 
the rest of the industry after that time. As proposed, the final rules 
require that manufacturers making use of these provisions for the 
optional standard would need to exhaust all credits available to this 
averaging set prior to using this flexibility and would not be able to 
generate emissions credits from other engines in the same regulatory 
averaging set as the engines complying using this alternate approach.
    The agencies note again that manufacturers choosing to utilize this 
option in MYs 2014-2016 will have to make a greater relative 
improvement in MY 2017 than the rest of the industry, since they will 
be starting from a worse level--for compliance purposes, emissions from 
engines certified and sold at the three percent level will be averaged 
with emissions from engines certified and sold at more stringent levels 
to arrive at a weighted average emissions for all engines in the 
subcategory. Again, this option can only be taken if all other credit 
opportunities have been exhausted and the manufacturer still cannot 
meet the primary standards. If a manufacturer chooses this option to 
meet the EPA emission standards in the MY 2014-2016, and wants to opt 
into the NHTSA fuel consumption program in these same MYs it must 
follow the exact path followed under the EPA program utilizing 
equivalent fuel consumption standards. Since the NHTSA standards are 
optional in 2014, manufacturers may choose not to adopt either the 
alternative engine standard or the regular voluntary standard by not 
participating in the NHTSA program in 2014 and 2015.
    Some commenters argued that manufacturers could game the standard 
by establishing an artificially high 2011 baseline emission level. This 
could be done, for example, by certifying an engine with high fuel 
consumption and GHG emissions that is either: (1) Not sold in 
significant quantities; or (2) later altered to emit fewer GHGs and 
consume less fuel through service changes. In order to mitigate this 
possibility, the agencies are requiring that the 2011 model year 
baseline must be developed by averaging emissions over all engines in 
an engine family certified and sold for that model year so as to 
prevent a manufacturer from developing a single high GHG output engine 
solely for the purpose of establishing a high baseline. As an 
alternative, if a manufacturer does not certify all engine families in 
an averaging set to the alternate standards, then the tested 
configuration of the engine certified to the alternate standard must 
have the same engine displacement and its rated power within 5 percent 
of the highest rated power of the baseline tested configuration. In 
addition, the tested configuration of the engine certified to the 
alternate standard must be a configuration sold to customers. These 
three requirements will prevent a manufacturer from producing an engine 
with an artificially high power rating and therefore produce 
artificially low grams of CO2 emissions and fuel consumption 
per brake horsepower. In addition, the tested configurations must have 
a BSFC equivalent to or better than all other configurations within the 
engine family which will prevent a manufacturer from creating a 
baseline configuration with artificially high CO2 emissions 
and fuel consumption.
(c) In-Use Standards
    Section 202(a)(1) of the CAA specifies that EPA is to adopt 
emissions standards that are applicable for the useful life of the 
vehicle. The in-use standards that EPA is finalizing would apply to 
individual vehicles and engines. NHTSA is adopting an approach which 
does not include in-use standards.
    EPA proposed that the in-use standards for heavy-duty engines 
installed in tractors be established by adding an adjustment factor to 
the full useful life emissions and fuel consumption results projected 
in the EPA certification process to address measurement variability 
inherent in comparing results among different laboratories and 
different engines. The agency proposed a two percent adjustment factor 
and requested comments and additional data during the proposal to 
assist in developing an appropriate factor level. The agency received 
additional data during the comment period which identified production 
variability which was not accounted for at proposal. Details on the 
development of the final adjustment factor are included in RIA Chapter 
3. Based on the data received, EPA determined that the adjustment 
factor in the final rules should be higher than the proposed level of 
two percent. EPA is finalizing a three percent adjustment factor for 
the in-use standard to provide a reasonable margin for production and 
test-to-test variability that could result in differences between the 
initial emission test results and emission results obtained during 
subsequent in-use testing.
    We are finalizing regulatory text (in Sec.  1036.150) to allow 
engine manufacturers to used assigned

[[Page 57146]]

deterioration factors (DFs) without performing their own durability 
emission tests or engineering analysis. However, the engines would 
still be required to meet the standards in actual use without regard to 
whether the manufacturer used the assigned DFs. This allowance is being 
adopted as an interim provision applicable only for this initial phase 
of standards.
    Manufacturers will be allowed to use an assigned additive DF of 0.0 
g/bhp-hr for CO2 emissions from any conventional engine 
(i.e., an engine not including advance or innovative technologies). 
Upon request, we could allow the assigned DF for CO2 
emissions from engines including advance or innovative technologies, 
but only if we determine that it would be consistent with good 
engineering judgment. We believe that we have enough information about 
in-use CO2 emissions from conventional engines to conclude 
that they will not increase as the engines age. However, we lack such 
information about the more advanced technologies.
    EPA is also finalizing the proposed provisions requiring that the 
useful life for these engine and vehicles with respect to GHG emissions 
be set equal to the respective useful life periods for criteria 
pollutants. EPA is adopting provisions where the existing engine useful 
life periods, as included in Table II-6, be broadened to include 
CO2 emissions for both engines (See 40 CFR 1036.108(d)) and 
tractors (See 40 CFR 1037.105).

           Table II-6--Tractor and Engine Useful Life Periods
------------------------------------------------------------------------
                                                      Years      Miles
------------------------------------------------------------------------
Medium Heavy-Duty Diesel Engines..................         10    185,000
Heavy Heavy-Duty Diesel Engines...................         10    435,000
Class 7 Tractors..................................         10    185,000
Class 8 Tractors..................................         10    435,000
------------------------------------------------------------------------

(3) Test Procedures and Related Issues
    The agencies are finalizing a complete set of test procedures to 
evaluate fuel consumption and CO2 emissions from Class 7 and 
8 tractors and the engines installed in them. Consistent with the 
proposal, the test procedures related to the tractors are all new, 
while the engine test procedures already established were built 
substantially on EPA's current non-GHG emissions test procedures, 
except as noted. This section discusses the final simulation model 
developed for demonstrating compliance with the tractor standard and 
the final engine test procedures.
(a) Vehicle Simulation Model
    We are finalizing as proposed separate engine and vehicle-based 
emission standards to achieve the goal of reducing emissions and fuel 
consumption for both combination tractors and engines. Engine 
manufacturers are subject to the engine standards while the Class 7 and 
8 tractor manufacturers are required to install certified engines in 
their tractors. The tractor manufacturer is also subject to a separate 
vehicle-based standard which utilizes a vehicle simulation model to 
evaluate the impact of the tractor cab design to determine compliance 
with the tractor standard.
    A simulation model, in general, uses various inputs to characterize 
a vehicle's properties (such as weight, aerodynamics, and rolling 
resistance) and predicts how the vehicle would behave on the road when 
it follows a driving cycle (vehicle speed versus time). On a second-by-
second basis, the model determines how much engine power needs to be 
generated for the vehicle to follow the driving cycle as closely as 
possible. The engine power is then transmitted to the wheels through 
transmission, driveline, and axles to move the vehicle according to the 
driving cycle. The second-by-second fuel consumption of the vehicle, 
which corresponds to the engine power demand to move the vehicle, is 
then calculated according to a fuel consumption map in the model. 
Similar to a chassis dynamometer test, the second-by-second fuel 
consumption is aggregated over the complete drive cycle to determine 
the fuel consumption of the vehicle.
    Consistent with the proposal, NHTSA and EPA are finalizing a 
procedure to evaluate fuel consumption and CO2 emissions 
respectively through a simulation of whole-vehicle operation, 
consistent with the NAS recommendation to use a truck model to evaluate 
truck performance.\72\ The EPA developed the Greenhouse gas Emissions 
Model (GEM) for the specific purpose of this rulemaking to evaluate 
truck performance. The GEM is similar in concept to a number of vehicle 
simulation tools developed by commercial and government entities. The 
model developed by the EPA and finalized here was designed for the 
express purpose of vehicle compliance demonstration and is therefore 
simpler and less configurable than similar commercial products. This 
approach gives a compact and quicker tool for vehicle compliance 
without the overhead and costs of a more sophisticated model. Details 
of the model are included in Chapter 4 of the RIA. The agencies are 
aware of several other simulation tools developed by universities and 
private companies. Tools such as Argonne National Laboratory's 
Autonomie, Gamma Technologies' GT-Drive, AVL's CRUISE, Ricardo's VSIM, 
Dassault's DYMOLA, and University of Michigan's HE-VESIM codes are 
publicly available. In addition, manufacturers of engines, vehicles, 
and trucks often have their own in-house simulation tools. The agencies 
sought comments regarding other software packages which would better 
serve the compliance purposes of the rules than the GEM, but did not 
receive any recommendations.
---------------------------------------------------------------------------

    \72\ See 2010 NAS Report. Note 21, Recommendation 8-4. Page 190.
---------------------------------------------------------------------------

    The GEM is designed to focus on the inputs most closely associated 
with fuel consumption and CO2 emissions--i.e., on those 
which have the largest impacts such as aerodynamics, rolling 
resistance, weight, and others.
    EPA has validated the GEM based on the chassis test results from 
two combination tractors tested at Southwest Research Institute. The 
validation work conducted on this vehicle was representative of the 
other Class 7 and 8 tractors. Many aspects of one tractor configuration 
(such as the engine, transmission, axle configuration, tire sizes, and 
control systems) are similar to those used on the manufacturer's sister 
models. For example, the powertrain configuration of a sleeper cab with 
any roof height is similar to the one used on a day cab with any roof 
height. Overall, the GEM predicted the fuel consumption and 
CO2 emissions within 2 percent of the chassis test procedure 
results for three test cycles--the California ARB Transient cycle, 65 
mph cruise cycle, and 55 mph cruise cycle. These cycles are the ones 
the agencies are utilizing in compliance testing. Since the time of the 
proposal, the EPA also conducted a validation of the GEM relative to a 
commonly used vehicle simulation software, GT-Power. The results of 
this validation found that the two software programs predicted the fuel 
efficiency of each subcategory of tractor to be within 2 percent. Test 
to test variation for heavy-duty vehicle chassis testing can be higher 
than 4 percent due to driver variation alone. The final simulation 
model is described in greater detail in Chapter 4 of the RIA and is 
available for download by at (http://www.epa.gov/otaq/climate/regulations.htm).
    After proposal, the agencies conducted a peer review of GEM version 
1.0 which was proposed. In addition, we requested comment on all 
aspects of

[[Page 57147]]

this approach to compliance determination in general and to the use of 
the GEM in particular. The agencies received comments from stakeholders 
and made changes for the release of GEM v2.0 to address concerns raised 
in the comments, along with the comments received during the peer 
review process. The most noticeable changes to the GEM include 
improvements to the graphical user interface (GUI). In response to 
comments, the agencies have reduced the amount of information required 
in the Identification section; linked the inputs to the selected 
subcategory while graying-out the items that are not applicable to the 
subcategory; and added batch modeling capability to reduce the 
compliance burden to manufacturers. In addition, substantial work went 
into model validations and benchmarking against vehicle test data and 
other commonly used vehicle simulation models.
    The model also includes a new driver model, a simplified electric 
system model, and revised engine fuel maps to better reflect the 2017 
model year engine standards. The model in the final rulemaking uses the 
targeted vehicle driving speed to estimate vehicle torque demand at any 
given time, and then the power required to drive the vehicle is derived 
to estimate the required accelerator and braking pedal positions. If 
the driver misses the vehicle speed target, a speed correction logic 
controlled by a PID controller is applied to adjust necessary 
accelerator and braking pedal positions in order to match targeted 
vehicle speed at every simulation time step. The enhanced driver model 
used in the final rulemaking with its feed-forward driver controls more 
realistically models driving behavior. The GEM v1.0, the proposed 
version of the model, had four individual components to model the 
electric system--starter, electrical energy system, alternator, and 
electrical accessory. For the final rulemaking, the GEM v2.0 has a 
single electric system model with a constant power consumption level. 
Based on comments received, the agencies revisited the 2017 model year 
proposed fuel maps, specifically the low load area, which was 
extrapolated during the proposal and (incorrectly) generated negative 
improvements. The agencies redeveloped the fuel maps for the final 
rulemaking to better predict the fuel consumption of engines in this 
area of the fuel consumption map. Details of the changes are included 
in RIA Chapter 4.
    To demonstrate compliance, a Class 7 and 8 tractor manufacturer 
will measure the performance of specified tractor systems (such as 
aerodynamics and tire rolling resistance), input the values into the 
GEM, and compare the model's output to the standard. The rules require 
that a tractor manufacturer provide the inputs for each of following 
factors for each of the tractors it wishes to certify under 
CO2 standards and for establishing fuel consumption values: 
Coefficient of Drag, Tire Rolling Resistance Coefficient, Weight 
Reduction, Vehicle Speed Limiter, and Extended Idle Reduction 
Technology. These are the technologies on which the agencies' own 
feasibility analysis for these vehicles is predicated. An example of 
the GEM input screen is included in Figure II-1.
[GRAPHIC] [TIFF OMITTED] TR15SE11.001

    For the aerodynamic assessment, tire rolling resistance, and 
tractor weight reduction, the input values for the simulation model 
will be determined by the manufacturer through conducting tests using 
the test procedures finalized

[[Page 57148]]

by the agencies in this action and described below. The agencies are 
allowing several testing alternatives for aerodynamic assessment 
referenced back to a coastdown test procedure, a single procedure for 
determination of the coefficient of rolling resistance (CRR) for tires, 
and a prescribed method to determine tractor weight reduction. The 
agencies have finalized defined model inputs for determining vehicle 
speed limiter and extended idle reduction technology benefits. The 
other aspects of vehicle performance are fixed within the model as 
defined by the agencies and are not varied for the purpose of 
compliance.
(b) Metric
    Test metrics which are quantifiable and meaningful are critical for 
a regulatory program. The CO2 and fuel consumption metric 
should reflect what we wish to control (CO2 or fuel 
consumption) relative to the clearest value of its use: in this case, 
carrying freight. It should encourage efficiency improvements that will 
lead to reductions in emissions and fuel consumption during real world 
operation. The agencies are finalizing standards for Class 7 and 8 
combination tractors that would be expressed in terms of moving a ton 
(2,000 pounds) of freight over one mile. Thus, NHTSA's final fuel 
consumption standards for these trucks would be represented as gallons 
of fuel used to move one ton of freight 1,000 miles, or gal/1,000 ton-
mile. EPA's final CO2 vehicle standards would be represented 
as grams of CO2 per ton-mile. The model converts 
CO2 emissions to fuel consumption using the CO2 
grams per ton mile estimated by GEM and an assumed 10,180 grams of 
CO2 per gallon of diesel fuel.
    This approach tracks the recommendations of the NAS report. The NAS 
panel concluded, in their report, that a load-specific fuel consumption 
metric is appropriate for HD trucks. The panel spent considerable time 
explaining the advantages of and recommending a load-specific fuel 
consumption approach to regulating the fuel efficiency of heavy-duty 
trucks. See NAS Report pages 20 through 28. The panel first points out 
that the nonlinear relationship between fuel economy and fuel 
consumption has led consumers of light-duty vehicles to have difficulty 
in judging the benefits of replacing the most inefficient vehicles. The 
panel describes an example where a light-duty vehicle can save the same 
107 gallons per year (assuming 12,000 miles travelled per year) by 
improving one vehicle's fuel efficiency from 14 to 16 mpg or improving 
another vehicle's fuel efficiency from 35 to 50.8 mpg. The use of miles 
per gallon leads consumers to undervalue the importance of small mpg 
improvements in vehicles with lower fuel economy. Therefore, the NAS 
panel recommends the use of a fuel consumption metric over a fuel 
economy metric. The panel also describes the primary purpose of most 
heavy-duty vehicles as moving freight or passengers (the payload). 
Therefore, they concluded that the most appropriate way to represent an 
attribute-based fuel consumption metric is to normalize the fuel 
consumption to the payload.
    With the approach to compliance NHTSA and EPA are adopting, a 
default payload is specified for each of the tractor categories 
suggesting that a gram per mile metric with a specified payload and a 
gram per ton-mile metric would be effectively equivalent. The primary 
difference between the metrics and approaches relates to our treatment 
of mass reductions as a means to reduce fuel consumption and greenhouse 
gas emissions. In the case of a gram per mile metric, mass reductions 
are reflected only in the calculation of the work necessary to move the 
vehicle mass through the drive cycle. As such it directly reduces the 
gram emissions in the numerator since a vehicle with less mass will 
require less energy to move through the drive cycle leading to lower 
CO2 emissions. In the case of Class 7 and 8 tractors and our 
gram/ton-mile metric, reductions in mass are reflected both in less 
mass moved through the drive cycle (the numerator) and greater payload 
(the denominator). We adjust the payload based on vehicle mass 
reductions because we estimate that approximately one third of the time 
the amount of freight loaded in a trailer is limited not by volume in 
the trailer but by the total gross vehicle weight rating of the 
tractor. By reducing the mass of the tractor the mass of the freight 
loaded in the vehicle can go up. Based on this general approach, it can 
be estimated that for every 1,200 pounds in mass reduction across all 
Class 7 and 8 tractors on the road, that total vehicle miles traveled, 
and therefore trucks on the road, could be reduced by one percent. 
Without the use of a per ton-mile metric it would not be clear or 
straightforward for the agencies to reflect the benefits of mass 
reduction from large freight carrying vehicles that are often limited 
in the freight they carry by the gross vehicle weight rating of the 
vehicle. There was strong consensus in the public comments for adopting 
the proposed metrics for tractors.
(c) Vehicle Aerodynamic Assessment
    The aerodynamic drag of a vehicle is determined by the vehicle's 
coefficient of drag (Cd), frontal area, air density and speed. As noted 
in the NPRM, quantifying truck aerodynamics as an input to the GEM 
presents technical challenges because of the proliferation of vehicle 
configurations, the lack of a clearly preferable standardized test 
method, and subtle variations in measured aerodynamic values among 
various test procedures. Class 7 and 8 tractor aerodynamics are 
currently developed by manufacturers using a range of techniques, 
including wind tunnel testing, computational fluid dynamics, and 
constant speed tests.
    Consistent with our discussion at proposal, we believe a broad 
approach allowing manufacturers to use these multiple different test 
procedures to demonstrate aerodynamic performance of its tractor fleet 
is appropriate given that no single test procedure is superior in all 
aspects to other approaches. Allowing manufacturers to use multiple 
test procedures and modeling coupled with good engineering judgment to 
determine aerodynamic performance is consistent with the current 
approach used in determining representative road load forces for light-
duty vehicle testing (40 CFR 86.129-00(e)(1)). However, we also 
recognize the need for consistency and a level playing field in 
evaluating aerodynamic performance.
    The agencies are retaining an aerodynamic bin structure for the 
final rulemaking, but are adjusting the method used to determine the 
bins. To address the consistency and level playing field concerns, 
NHTSA and EPA proposed that manufacturers use a two-part screening 
approach for determining the aerodynamic inputs to the GEM. The first 
part would have required the manufacturers to assign each vehicle 
aerodynamic configuration based on descriptions of vehicle 
characteristics to one of five aerodynamics bins created by EPA and 
NHTSA. The proposed assignment by bin would have fixed (by rule) the 
aerodynamic characteristics of the vehicle. However, the agencies, 
while working with industry, concluded for the final rulemaking that an 
approach which identified a reference aerodynamic test method and a 
procedure to align results from other aerodynamic test procedures with 
the reference method is a simpler, more accurate approach than 
deciphering and interpreting written descriptions of aerodynamic 
components.
    Therefore, we are finalizing an approach, as described in Section 
V.B.3.d and Sec.  1037.501, which uses an

[[Page 57149]]

enhanced coastdown procedure as a reference method and defines a 
process for manufacturers to align drag results from each of their own 
test methods to the reference method results. Manufacturers will be 
able to use any aerodynamic evaluation method in demonstrating a 
vehicle's aerodynamic performance as long as the method is aligned to 
the reference method. The results from the aerodynamic testing will be 
the single determining factor for aerodynamic bin assignments.
    EPA and NHTSA recognize that wind conditions, most notably wind 
direction, have a greater impact on real world CO2 emissions 
and fuel consumption of heavy-duty trucks than of light-duty vehicles. 
As noted in the NAS report,\73\ the wind average drag coefficient is 
about 15 percent higher than the zero degree coefficient of drag. In 
addition, the agencies received comments that supported the use of wind 
averaged drag results for the aerodynamic determination. The agencies 
considered finalizing the use of a wind averaged drag coefficient in 
this regulatory program, but ultimately decided to finalize drag values 
which represent zero yaw (i.e., representing wind from directly in 
front of the vehicle, not from the side) instead. We are taking this 
approach recognizing that the reference method is coastdown testing 
which is not capable of determining wind averaged yaw. Wind tunnels are 
currently the only tool which can accurately assess the influence of 
wind speed and direction on a vehicle's aerodynamic performance. The 
agencies recognize, as NAS did, that the results of using the zero yaw 
approach may result in fuel consumption predictions that are offset 
slightly from real world performance levels, not unlike the offset we 
see today between fuel economy test results in the CAFE program and 
actual fuel economy performance observed in-use. We believe this 
approach will not impact overall technology effectiveness or change the 
kinds of technology decisions made by the tractor manufacturers in 
developing equipment to meet our final standards. However, the agencies 
are adopting provisions which allow manufacturers to generate credits 
reflecting performance of technologies which improve the aerodynamic 
performance in crosswind conditions, similar to those experienced by 
vehicles in use through innovative technologies, as described in 
Section IV.
---------------------------------------------------------------------------

    \73\ See 2010 NAS Report, Note 21, Finding 2-4 on page 39.
---------------------------------------------------------------------------

    As just noted, the agencies are adopting an approach for this final 
action where the manufacturer would determine a tractor's aerodynamic 
drag force using their own aerodynamic assessment tools and correlating 
the results back to the reference aerodynamic test method of enhanced 
coastdown testing. The manufacturer determines the appropriate 
predefined aerodynamic bin based on the correlated test results and 
then inputs the predefined Cd value for that aerodynamic bin into the 
GEM. Coefficient of drag and frontal area of the tractor-trailer 
combination go hand-in-hand to determine the force required to overcome 
aerodynamic drag. The agencies proposed that the Cd value would be a 
GEM input derived by the manufacturer and that the agencies would 
specify the vehicle's frontal area for each regulatory subcategory. The 
agencies sought and received comment recommending an alternate approach 
where the aerodynamic input tables (as shown in Table 0-7 and Table 0-
8) represent the drag force as defined as Cd multiplied by the frontal 
area. Because both approaches are essentially equivalent and the use of 
CdA more directly relates back to the aerodynamic testing, the agencies 
are finalizing the use of CdA as recommended by manufacturers.
    The agencies are finalizing aerodynamic technology bins which 
divide the wide spectrum of tractor aerodynamics into five bins (i.e., 
categories) for high roof tractors. The first high roof category, Bin 
I, is designed to represent tractor bodies which prioritize appearance 
or special duty capabilities over aerodynamics. These Bin I trucks 
incorporate few, if any, aerodynamic features and may have several 
features which detract from aerodynamics, such as bug deflectors, 
custom sunshades, B-pillar exhaust stacks, and others. The second high 
roof aerodynamics category is Bin II which roughly represents the 
aerodynamic performance of the average new tractor sold today. The 
agencies developed this bin to incorporate conventional tractors which 
capitalize on a generally aerodynamic shape and avoid classic features 
which increase drag. High roof tractors within Bin III build on the 
basic aerodynamics of Bin II tractors with added components to reduce 
drag in the most significant areas on the tractor, such as integral 
roof fairings, side extending gap reducers, fuel tank fairings, and 
streamlined grill/hood/mirrors/bumpers, similar to SmartWay trucks 
today. The Bin IV aerodynamic category for high roof tractors builds 
upon the Bin III tractor body with additional aerodynamic treatments 
such as underbody airflow treatment, down exhaust, and lowered ride 
height, among other technologies. And finally, Bin V tractors 
incorporate advanced technologies which are currently in the prototype 
stage of development, such as advanced gap reduction, rearview cameras 
to replace mirrors, wheel system streamlining, and advanced body 
designs.
    The agencies had proposed five aerodynamic bins for each tractor 
regulatory subcategory. The agencies received comments from ATA, EMA/
TMA, and Volvo indicating that this approach was not consistent with 
the aerodynamics of low and mid roof tractors. High roof tractors are 
consistently paired with box trailer designs, and therefore 
manufacturers can design the tractor aerodynamics as a tractor-trailer 
unit and target specific areas like the gap between the tractor and 
trailer. In addition, the high roof tractors tend to spend more time at 
high speed operation which increases the impact of aerodynamics on fuel 
consumption and GHG emissions. On the other hand, low and mid roof 
tractors are designed to pull variable trailer loads and shapes. They 
may pull trailers such as flat bed, low boy, tankers, or bulk carriers. 
The loads on flat bed trailers can range from rectangular cartons with 
tarps, to a single roll of steel, to a front loader. Due to these 
variables, manufacturers do not design unique low and mid roof tractor 
aerodynamics but instead use derivatives from their high roof tractor 
designs. The aerodynamic improvements to the bumper, hood, windshield, 
mirrors, and doors are developed for the high roof tractor application 
and then carried over into the low and mid roof applications. As 
mentioned above, the types of designs that would move high roof 
tractors from a Bin III to Bins IV and V include features such as gap 
reducers and integral roof fairings which would not be appropriate on 
low and mid roof tractors. The agencies considered and largely agree 
with these comments and are therefore finalizing only two aerodynamic 
bins for low and mid roof tractors. The agencies are reducing the 
number of bins to reflect the actual range of aerodynamic technologies 
effective in low and mid roof tractor applications. Thus, the agencies 
are differentiating the aerodynamic performance for low and mid roof 
applications into two bins--conventional and aerodynamic.\74\
---------------------------------------------------------------------------

    \74\ As explained in Section IV, there are no ABT implications 
to this change from proposal, since all Class 8 combination tractors 
are considered to be a single averaging set for ABT purposes. 
Similarly, all Class 7 tractors are considered to be a single 
averaging set for ABT purposes.

---------------------------------------------------------------------------

[[Page 57150]]

    For high roof combination tractor compliance determination, a 
manufacturer would use the aerodynamic results determined through 
testing to establish the appropriate bin. The manufacturer would then 
input into GEM the Cd value specified for each bin as defined in Table 
II-7 and Table II-8. For example, if a manufacturer tests a Class 8 
sleeper cab high roof tractor and the test produces a CdA value between 
5.8 and 6.6, the manufacturer would assign this tractor to the Class 8 
Sleeper Cab High Roof Bin III. The manufacturer would then use the Cd 
value identified for Bin III of 0.60 as the input to GEM.
    The Cd values in Table II-7 and Table II-8 differ from proposal 
based on a change in the reference method (enhanced coastdown 
procedure) and additional testing conducted by EPA. Details of the test 
program and results are included in RIA Chapter 2.5.1.4.

 Table II-7--Aerodynamic Input Definitions to GEM for High Roof Tractors
------------------------------------------------------------------------
                                     Class 7             Class 8
                                  --------------------------------------
                                     Day cab      Day cab    Sleeper cab
                                  --------------------------------------
                                    High roof    High roof   High roof >
------------------------------------------------------------------------
                 Aerodynamic Test Results (CdA in m\2\)
------------------------------------------------------------------------
Bin I............................       >= 8.0       >= 8.0       >= 7.6
Bin II...........................      7.1-7.9      7.1-7.9      6.7-7.5
Bin III..........................      6.2-7.0      6.2-7.0      5.8-6.6
Bin IV...........................      5.6-6.1      5.6-6.1      5.2-5.7
Bin V............................       <= 5.5       <= 5.5       <= 5.1
------------------------------------------------------------------------
                      Aerodynamic Input to GEM (Cd)
------------------------------------------------------------------------
Bin I............................         0.79         0.79         0.75
Bin II...........................         0.72         0.72         0.68
Bin III..........................         0.63         0.63         0.60
Bin IV...........................         0.56         0.56         0.52
Bin V............................         0.51         0.51         0.47
------------------------------------------------------------------------

    The CdA values in Table II-8 are based on testing using the 
enhanced coastdown test procedures adopted for the final rulemaking, 
which includes aerodynamic assessment of the low and mid roof tractors 
without a trailer. The removal of the trailer significantly reduces the 
CdA value of mid roof tractors with tanker trailers because of the poor 
aerodynamic performance of the tanker trailer. The agencies developed 
the Cd input for each of the low and mid roof tractor bins to represent 
the Cd of the tractor, its frontal area, and the impact of the Cd value 
due to the trailer such that the GEM value is representative of a 
tractor-trailer combination, as it is for the high roof tractors.

                                     Table II-8--Aerodynamic Input Definitions to GEM for Low and Mid Roof Tractors
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Class 7                                      Class 8
                                                                   ------------------------------------------------------------------------------------------
                                                                                                Day Cab                          Day Cab            Sleeper
                                                                                ----------------------------------------------------------------      Cab
                                                                                                                                                 ------------
                                                                                                Low Roof     Mid Roof     Low Roof     Mid Roof    Low
                                                                                                                                                  Roof
------------------------------------------------------------------------------------------------------------------------------------------------ ------------
                                                     Aerodynamic Test Results (CdA in m\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin I.............................................................       >= 5.1       >= 5.6       >= 5.1       >= 5.6       >= 5.1       >= 5.6
Bin II............................................................       <= 5.0       <= 5.5       <= 5.0       <= 5.5       <= 5.0       <= 5.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Aerodynamic Input to GEM (Cd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin I.............................................................         0.77         0.87         0.77         0.87         0.77         0.87
Bin II............................................................         0.71         0.82         0.71         0.82         0.71         0.82
--------------------------------------------------------------------------------------------------------------------------------------------------------

(d) Tire Rolling Resistance Assessment
    NHTSA and EPA are finalizing as proposed that the tractor's tire 
rolling resistance input to the GEM be determined by either the tire 
manufacturer or tractor manufacturer using the test method adopted by 
the International Organization for Standardization, ISO 28580:2009.\75\ 
The agencies believe the ISO test procedure is appropriate for this 
program because the procedure is the same one used by NHTSA in its fuel 
efficiency tire labeling program \76\ and is consistent with the 
testing direction being taken by

[[Page 57151]]

the tire industry both in the United States and Europe. The rolling 
resistance from this test would be used to specify the rolling 
resistance of each tire on the steer and drive axle of the tractor. The 
results would be expressed as a rolling resistance coefficient (CRR) 
and measured as kilogram per metric ton (kg/metric ton). The agencies 
are finalizing as proposed that three tire samples within each tire 
model be tested three times each to account for some of the production 
variability and the average of the nine tests would be the rolling 
resistance coefficient for the tire. The GEM will use the steer and 
drive tire rolling resistance inputs and distribute 15 percent of the 
gross weight of the tractor and trailer to the steer axle, 42.5 percent 
to the drive axles, and 42.5 percent to the trailer axles.\77\ The 
trailer tires' rolling resistance is prescribed by the agencies as part 
of the standardized trailer used for demonstrating compliance at 6 kg/
metric ton, which was the average trailer tire rolling resistance 
measured during the SmartWay tire testing.\78\
---------------------------------------------------------------------------

    \75\ ISO, 2009, Passenger Car, Truck, and Bus Tyres--Methods of 
Measuring Rolling Resistance--Single Point Test and Correlation of 
Measurement Results: ISO 28580:2009(E), First Edition, 2009-07-01
    \76\ NHTSA, 2009. ``NHTSA Tire Fuel Efficiency Consumer 
Information Program Development: Phase 1--Evaluation of Laboratory 
Test Protocols.'' DOT HS 811 119. June. (http://www.regulations.gov, 
Docket ID: NHTSA-2008-0121-0019).
    \77\ This distribution is equivalent to the federal over-axle 
weight limits for an 80,000 GVWR 5-axle tractor-trailer: 12,000 
pounds over the steer axle, 34,000 pounds over the tandem drive 
axles (17,000 pounds per axle) and 34,000 pounds over the tandem 
trailer axles (17,000 pounds per axle).
    \78\ U.S. Environmental Protection Agency. SmartWay Transport 
Partnership July 2010 e-update accessed July 16, 2010, from http://www.epa.gov/smartwaylogistics/newsroom/documents/e-update-july-10.pdf.
---------------------------------------------------------------------------

    EPA and NHTSA conducted additional evaluation testing on HD trucks 
tires used for tractors, and also for vocational vehicles. The agencies 
also received several comments on the suitability of low rolling 
resistance tires for various HD vehicle applications. The summary of 
the agencies' findings and a response to issues raised by commenters is 
presented in Section II.D(1)(a).
(e) Weight Reduction Assessment
    The agencies proposed that the tractor standards reflect improved 
CO2 emissions and fuel consumption performance of a 400 
pound weight reduction in Class 7 and 8 tractors through the 
substitution of single wide tires and light-weight wheels for dual 
tires and steel wheels. This approach was taken since there is a large 
variation in the baseline weight among trucks that perform roughly 
similar functions with roughly similar configurations. Because of this, 
the only effective way to quantify the exact CO2 and fuel 
consumption benefit of mass reduction using GEM is to estimate baseline 
weights for specific components that can be replaced with light weight 
components. If the weight reduction is specified for light weight 
versions of specific components, then both the baseline and weight 
differentials for these are readily quantifiable and well-understood. 
Lightweight wheels are commercially available as are single wide tires 
and thus data on the weight reductions attributable to these two 
approaches are readily available.
    The agencies received comments on this approach from Volvo, ATA, 
MEMA, Navistar, American Chemistry Council, the Auto Policy Center, 
Iron and Steel Institute, Arvin Meritor, Aluminum Association, and 
environmental groups and NGOs. Volvo and ATA stated that not all fleets 
can use single wide tires and if this is the case the 400 pound weight 
reduction target cannot be met. Volvo stated that without the use of 
single wide drive tires, a 6x4 tractor will have a maximum weight 
reduction of 300 pounds if the customer selects all ten wheels to be 
outfitted with light weight aluminum wheels. A number of additional 
commenters--including American Chemistry Council, The Auto Policy 
Center, Iron and Steel Institute, Aluminum Association, Arvin Meritor, 
MEMA, Navistar, Volvo, and environmental and nonprofit groups--stated 
that manufacturers should be allowed to use additional light weight 
components in order to meet the tractor fuel consumption and 
CO2 emissions standards. These groups stated that weight 
reductions should not be limited to wheels and tires. They asked that 
cab doors, cab sides and backs, cab underbodies, frame rails, cross 
members, clutch housings, transmission cases, axle differential carrier 
cases, brake drums, and other components be allowed to be replaced with 
light-weight versions. Materials suggested for substitution included 
aluminum, light-weight aluminum, high strength steel, and plastic 
composites. The American Iron and Steel Institute stated there are 
opportunities to reduce mass by replacing mild steel--which currently 
dominates the heavy-duty industry--with high strength steel.
    In addition, The American Auto Policy Center asked that 
manufacturers be allowed to use materials other than aluminum and high 
strength steel to comply with the regulations. DTNA asked that weight 
reduction due to engine downsizing be allowed to receive credit. Volvo 
requested that weight reductions due to changes in axle configuration 
be credited. They used the example of a customer selecting a 4 X 2 over 
a 6 X 4 axle tractor. In this case, they assert there would be a 1,000 
pound weight savings from removing an axle.
    As proposed, many of the material substitutions could have been 
considered as innovative technologies for tractors and hence eligible 
for off cycle credits (so that the commenters overstated that these 
technologies were `disallowed'). Nonetheless in response to the above 
summarized comments, the agencies evaluated whether additional 
materials and components could be used directly for compliance with the 
tractor weight reduction through the primary program (i.e. be available 
as direct inputs to the GEM). The agencies reviewed comments and data 
received in response to the NPRM and additional studies cited by 
commenters. A summary of this review is provided in the following 
paragraphs.
    TIAX, in their report to the NAS, cited information from Alcoa 
identifying several mass reduction opportunities from material 
substitution in the tractor cab components which were similar to the 
ones identified by the Aluminum Association in their comments to this 
rulemaking.\79\ TIAX included studies submitted by Alcoa showing the 
potential to reduce the weight of a tractor-trailer combination by 
3,500 to 4,500 pounds.\80\ In addition, the U.S. Department of Energy 
has several projects underway to improve the freight efficiency of 
Class 8 trucks which provide relevant data: \81\ DOE reviewed 
prospective lightweighting alternative materials and found that 
aluminum has a potential to reduce mass by 40 to 60 percent, which is 
in line with the estimates of mass reductions of various components 
provided by Alcoa, and by the Aluminum Association in their comments 
and as cited in the TIAX report. These combined studies, comments, and 
additional data provided information on specific components that could 
be replaced with aluminum components.
---------------------------------------------------------------------------

    \79\ TIAX, LLC. ``Assessment of Fuel Economy Technologies for 
Medium- and Heavy-Duty Vehicles,'' Final Report to National Academy 
of Sciences, November 19, 2009. Pages 4-62 through 4-64.
    \80\ Alcoa. ``Improving Sustainability of Transport: Aluminum is 
Part of the Solution.'' 2009.
    \81\ Schutte, Carol. U.S. Department of Energy, Vehicle 
Technologies Program. ``Losing Weight--an enabler for a Systems 
Level Technology Development, Integration, and Demonstration for 
Efficient Class 8 Trucks (SuperTruck) and Advanced Technology 
Powertrains for Light-Duty Vehicles.''
---------------------------------------------------------------------------

    With regard to high strength steel, the Iron and Steel Institute 
found that the use of high strength steel and redesign can reduce the 
weight of light-duty trucks by 25 percent.\82\ Approximately

[[Page 57152]]

10 percent of this reduction results from material substitution and 15 
percent from vehicle re-design. While this study evaluated light-duty 
trucks, the agencies believe that a similar reduction could be achieved 
in heavy-duty trucks since the reductions from material substitution 
would likely be similar in heavy-trucks as in light-trucks. U.S. DOE, 
in the report noted above, identified opportunities to reduce mass by 
10 percent through high strength steel.\83\ This study was also for 
light-duty vehicles.
---------------------------------------------------------------------------

    \82\ American Iron and Steel Institute. ``A Cost Benefit 
Analysis Report to the North American Steel Industry on Improved 
Materials and Powertrain Architectures for 21st Century Trucks.''
    \83\ Schutte, Carol. U.S. Department of Energy, Vehicle 
Technologies Program. ``Losing Weight--an enabler for a Systems 
Level Technology Development, Integration, and Demonstration for 
Efficient Class 8 Trucks (SuperTruck) and Advanced Technology 
Powertrains for Light-Duty Vehicles''.
---------------------------------------------------------------------------

    The agencies considered other materials such as plastic composites 
and magnesium substitutes but were not able to obtain weights for 
specific components made from these materials. We have therefore not 
included components made from these materials as possible substitutes 
in the primary program, but they may be considered through the 
innovative technology/off-cycle credits provision. We may consider 
including these materials as part of the primary compliance option in a 
subsequent regulation if data become available.
    Based on this analysis, the agencies developed an expanded list of 
weight reduction opportunities for the final rulemaking that may be 
reflected in the GEM, as listed in Table II-9. The list includes 
additional components, but not materials, from those proposed. For high 
strength steel, the weight reduction value is equal to 10 percent of 
the presumed baseline component weight, as the agencies used a 
conservative value based on the DOE report. We recognize that there may 
be additional potential for weight reduction in new high strength steel 
components which combine the reduction due to the material substitution 
along with improvements in redesign, as evidenced by the studies done 
for light-duty vehicles. In the development of the high strength steel 
component weights, we are only assuming a reduction from material 
substitution and no weight reduction from redesign, since we do not 
have any data specific to redesign of heavy-duty components nor do we 
have a regulatory mechanism to differentiate between material 
substitution and improved design. We are finalizing for wheels that 
both aluminum and light weight aluminum are eligible to be used as 
light-weight materials. Aluminum, but not light-weight aluminum, can be 
used as a light-weight material for other components. The reason for 
this is that data were available for light weight aluminum for wheels 
but were not available for other components.
    The agencies received comments on the proposal from the American 
Chemistry Council highlighting the role of plastics and composites in 
heavy-duty vehicles. As they stated, composites can be low density 
while having high strength and are currently used in applications such 
as oil pans and buses. The DOE mass reduction program demonstrated for 
heavy vehicles proof of concept designs for hybrid composite doors with 
an overall mass savings of 40 percent; 30 percent mass reduction of a 
hood system with carbon fiber sheet molding compound; 50 percent mass 
reduction from composite tie rods, trailing arms, and axles; and 
superplastically formed aluminum body panels.\84\ While the agencies 
recognize these opportunities, we do not believe the technologies have 
advanced far enough to quantify the benefits of these materials because 
they are very dependent on the actual composite material. The agencies 
may consider such lightweighting opportunities in future actions, but 
are not including them as part of this primary program. Manufacturers 
which opt to pursue composite and plastic material substitutions may 
seek credits through the innovative technology provisions.
---------------------------------------------------------------------------

    \84\ Schutte, Carol. U.S. Department of Energy, Vehicle 
Technologies Program. ``Losing Weight--an enabler for a Systems 
Level Technology Development, Integration, and Demonstration for 
Efficient Class 8 Trucks (SuperTruck) and Advanced Technology 
Powertrains for Light-Duty Vehicles''.
---------------------------------------------------------------------------

    With regard to Volvo's request that manufacturers be allowed to 
receive credit for trucks with fewer axles, the agencies recognize that 
vehicle options exist today which have less mass than other options. 
However, we believe the decisions to add or subtract such components 
will be made based on the intended use of the vehicle and not based on 
a crediting for the mass difference in our compliance program. It is 
not our intention to create a tradeoff between the right vehicle to 
serve a need (e.g. one with more or fewer axles) and compliance with 
our final standards. Therefore, we are not including provisions to 
credit (or penalize) vehicle performance based on the subtraction (or 
addition) of specific vehicle components. Table II-9 provides weight 
reduction values for different components and materials.

                   Table II-9--Weight Reduction Values
------------------------------------------------------------------------
 
------------------------------------------------------------------------
       Weight reduction technology        Weight reduction (lb per tire/
                                                      wheel)
------------------------------------------------------------------------
Single Wide Drive Tire with:
    Steel Wheel.........................                84
    Aluminum Wheel......................                139
    Light Weight Aluminum Wheel.........                147
Steer Tire or Dual Wide Drive Tire with:
    High Strength Steel Wheel...........                 8
    Aluminum Wheel......................                21
    Light Weight Aluminum Wheel.........                30
------------------------------------------------------------------------
      Weight reduction technologies          Aluminum      High strength
                                              weight       steel weight
                                             reduction       reduction
                                               (lb.)           (lb.)
------------------------------------------------------------------------
Door....................................              20               6
Roof....................................              60              18
Cab rear wall...........................              49              16
Cab floor...............................              56              18
Hood Support Structure..................              15               3

[[Page 57153]]

 
Fairing Support Structure...............              35               6
Instrument Panel Support Structure......               5               1
Brake Drums--Drive (4)..................             140              11
Brake Drums--Non Drive (2)..............              60               8
Frame Rails.............................             440              87
Crossmember--Cab........................              15               5
Crossmember--Suspension.................              25               6
Crossmember--Non Suspension (3).........              15               5
Fifth Wheel.............................             100              25
Radiator Support........................              20               6
Fuel Tank Support Structure.............              40              12
Steps...................................              35               6
Bumper..................................              33              10
Shackles................................              10               3
Front Axle..............................              60              15
Suspension Brackets, Hangers............             100              30
Transmission Case.......................              50              12
Clutch Housing..........................              40              10
Drive Axle Hubs (8).....................             160               4
Non Drive Front Hubs (2)................              40               5
Driveshaft..............................              20               5
Transmission/Clutch Shift Levers........              20               4
------------------------------------------------------------------------

    EPA and NHTSA are specifying the baseline vehicle weight for each 
regulatory vehicle subcategory (including the tires, wheels, frame, and 
cab components) in the GEM in aggregate based on weight of vehicles 
used in EPA's aerodynamic test program, but allow manufacturers to 
specify the use of light-weight components. The GEM then quantifies the 
weight reductions based on the pre-determined weight of the baseline 
component minus the pre-determined weight of the component made from 
light-weight material. Manufacturers cannot specify the weight of the 
light-weight component themselves, only the material used in the 
substitute component. The agencies assume the baseline wheel and tire 
configuration contains dual tires with steel wheels, along with steel 
frame and cab components, because these represent the vast majority of 
new vehicle configurations today. The weight reduction due to 
replacement of components with light weight versions will be reflected 
partially in the payload tons and partially in reducing the overall 
weight of the vehicle run in the GEM. The specified payload in the GEM 
will be set to the prescribed payload plus one third of the weight 
reduction amount to recognize that approximately one third of the truck 
miles are travelled at maximum payload, as discussed below in the 
payload discussion. The other two thirds of the weight reduction will 
be subtracted from the overall vehicle weight prescribed in the GEM.
    The agencies continue to believe that the 400 pound weight target 
is appropriate to use as a basis for setting the final combination 
tractor CO2 emissions and fuel consumption standards. The 
agencies agree with the commenter that 400 pounds of weight reduction 
without the use of single wide tires may not be achievable for all 
tractor configurations. As noted, the agencies have extended the list 
of weight reduction components in order to provide the manufacturers 
with additional means to comply with the combination tractors and to 
further encourage reductions in vehicle weight. The agencies considered 
increasing the target value beyond 400 pounds given the additional 
reduction potential identified in the expanded technology list; 
however, lacking information on the capacity for the industry to change 
to these lightweight components across the board by the 2014 model 
year, we have decided to maintain the 400 pound target. The agencies 
intend to continue to study the potential for additional weight 
reductions in our future work considering a second phase of vehicle 
fuel efficiency and GHG regulations. In the context of the current 
rulemaking for HD fuel consumption and GHG standards, one would expect 
that reducing the weight of medium-duty trucks similarly would, if 
anything, have a positive impact on safety. However, given the large 
difference in weight between light-duty and medium-duty vehicles, and 
even larger difference between light-duty vehicles and heavy-duty 
vehicles with loads, the agencies believe that the impact of weight 
reductions of medium- and heavy-duty vehicles would not have a 
noticeable impact on safety for any of these classes of vehicles.\85\
---------------------------------------------------------------------------

    \85\ For more information on the estimated safety effects of 
this rule, see Chapter 9 of the RIA.
---------------------------------------------------------------------------

(f) Extended Idle Reduction Technology Assessment
    Extended idling from Class 8 heavy-duty long haul combination 
tractors contributes to significant CO2 emissions and fuel 
consumption in the United States. The Federal Motor Carrier Safety 
Administration regulations require a certain amount of driver rest for 
a corresponding period of driving hours.\86\ Extended idle occurs when 
Class 8 long haul drivers rest in the sleeper cab compartment during 
rest periods as drivers find it both convenient and less expensive to 
rest in the tractor cab itself than to pull off the road and find 
accommodations.\87\ During this rest period a driver will idle the 
tractor engine in order to provide heating or cooling, or to run on-
board appliances. In some cases the engine can idle in excess of 10 
hours. During this period, the engine will consume approximately 0.8 
gallons of fuel and emit over 8,000 grams of CO2 per hour. 
An average tractor engine can consume 8 gallons of fuel and emit over 
80,000 grams of CO2 during overnight idling in such a case.
---------------------------------------------------------------------------

    \86\ Federal Motor Carrier Safety Administration. Hours of 
Service Regulations. Last accessed on August 2, 2010 at http://www.fmcsa.dot.gov/rules-regulations/topics/hos/.
    \87\ The agencies note that some sleeper cabs may be classified 
as vocational tractors and therefore are expected to primarily 
travel locally and would not benefit from an idle reduction 
technology.
---------------------------------------------------------------------------

    Idling reduction technologies (IRT) are available to allow for 
driver comfort while reducing fuel consumptions and CO2 
emissions. Auxiliary power units, fuel operated heaters, battery 
supplied air conditioning, and thermal storage systems are among the 
technologies

[[Page 57154]]

available today. The agencies are adopting a provision for use of 
extended idle reduction technology as an input to the GEM for Class 8 
sleeper cabs. As discussed further in Section III, if a manufacturer 
wishes to receive credit for using IRT to meet the standard, then an 
automatic main engine shutoff must be programmed and enabled, such that 
engine shutdown occurs after 5 minutes of idling, to help ensure the 
reductions are realized in-use. A discussion of the provisions the 
agencies are adopting for allowing an override of this automatic 
shutdown can be found in RIA Chapter 2. As with all of the technology 
inputs discussed in this section, the agencies are not mandating the 
use of idle reductions or idle shutdown, but rather allowing their use 
as one part of a suite of technologies feasible for reducing fuel 
consumption and meeting the final standards and using these 
technologies as the inputs to the GEM. The default value (5 g 
CO2/ton-mile or 0.5 gal/1,000 ton-mile) for the use of 
automatic engine shutdown (AES) with idle reduction technologies was 
determined as the difference between a baseline main engine with idle 
fuel consumption of 0.8 gallons per hour that idles 1,800 hours and 
travels 125,000 miles per year, and a diesel auxiliary power unit 
operating in lieu of main engine during those same idling hours. The 
agencies received various comments from ACEEE and MEMA regarding the 
assumptions used to derive the idle reduction value. ACEEE argued that 
the agencies should use a fuel consumption rate of 0.47 gallon/hour for 
main engine idling based on a paper written by Kahn. MEMA argued that 
the agencies should use a main engine idling fuel consumption rate of 
0.87 gal/hr, which is the midpoint of a DOE calculator reporting fuel 
consumption rates from 0.64 to 1.15 gal/hr at idling conditions, and 
between 800 and 1200 rpm with the air conditioning on and off, 
respectively. The agencies respectfully disagree with the 0.47 gal/hr 
recommendation because the same paper by Kahn shows that while idling 
fuel consumption is 0.47 gal/hr on average at 600 rpm, CO2 
emissions increase by 25 percent with A/C on at 600 rpm, and increase 
by 165 percent between 600 rpm and 1,100 rpm with A/C on.\88\ MEMA 
recommended using 2,500 hours per year for APU operation. They cited 
the SmartWay Web site which uses 2,400 hours per year (8 hours per day 
and 300 days per year). Also, they cited an Argonne study which assumed 
7 hours per day and 303 days per year, which equals 2,121 hours per 
year. Lastly, they referred to the FMCSA 2010 driver guidelines which 
reduce the number of hours driven per day by one to two hours, which 
would lead to 2,650 to 2,900 hours per year. The agencies reviewed 
other studies to quantify idling operations, as discussed in greater 
detail in RIA Section 2.5.4.2, and believe that the entirety of the 
research does not support a change from the proposed calculation. 
Therefore, the agencies are finalizing the calculation as proposed. 
Additional details regarding the comments, calculations, and agency 
decisions are included in RIA Section 2.5.4.2.
---------------------------------------------------------------------------

    \88\ See Gaines, L., A. Vyas, J. Anderson. ``Estimation of Fuel 
Used by Idling Commercial Trucks,'' Page 9 (2006).
---------------------------------------------------------------------------

    The agencies are adopting a provision to allow manufacturers to 
provide an AES system which is active for only a portion of a vehicle's 
life. In this case, a discounted idle reduction value would be entered 
into GEM. A discussion of the calculation of a discounted IRT credit 
can be found in Section III. Additional details on the emission and 
fuel consumption reduction values are included in RIA Section 2.5.4.2.
(g) Vehicle Speed Limiters
    The NPRM proposed to allow combination tractors that use vehicle 
speed limiters (VSL) to include the maximum governed speed value as an 
input to the GEM for purposes of determining compliance with the 
vehicle standards. The agencies also proposed not to assume the use of 
a mandatory vehicle speed limiter because of concerns about how to set 
a realistic application rate that avoids unintended consequences. See 
75 FR at 74223. Governing the top speed of a vehicle can reduce fuel 
consumption and GHG emissions, because fuel consumption and 
CO2 emissions increase proportionally to the square of 
vehicle speed.\89\ Limiting the speed of a vehicle reduces the fuel 
consumed, which in turn reduces the amount of CO2 emitted. 
The specific input to the GEM would be the maximum governed speed limit 
of the VSL that is programmed into the powertrain control module (PCM). 
The agencies stressed in the NPRM that in order to obtain a benefit in 
the GEM, a manufacturer must preset the limiter in such a way that the 
setting will not be ``capable of being easily overridden by the fleet 
or the owner.'' If the top speed could be easily overridden, the fuel 
consumption/CO2 benefits of the VSL might not be realized, 
and the agencies did not want to allow the technology to be used for 
compliance if the technology could be disabled easily and the real 
world benefits not achieved.
---------------------------------------------------------------------------

    \89\ See 2010 NAS Report, Note 21, Page 28. Road Load Force 
Equation defines the aerodynamic portion of the road load as 
[frac12] * Coefficient of Drag * Frontal Area * air density * 
vehicle speed squared.
---------------------------------------------------------------------------

    Both the Center for Biological Diversity (CBD) and New York State 
Department of Transportation and Environmental Conservation commented 
that the application of speed limiters should be used to set the 
tractor standards.\90\ CBD urged the agencies to reconsider the 
position and adopt a speed limitation technology. NY State commented 
that the technologies are cost effective, reduce emissions, and appear 
to be generally acceptable to the trucking industry. They continued to 
say that the vehicle speed limit could be set without compromising 
operational logistics.
---------------------------------------------------------------------------

    \90\ One commenter mistakenly thought that the agencies were 
rejecting consideration of VSLs due to perceived jurisdictional 
obstacles. In fact, both the CAA and EISA allow consideration of VSL 
technology and the agencies considered the appropriateness of basing 
standards on performance of the technology.
---------------------------------------------------------------------------

    Many commenters (Cummins, Daimler, EMA/TMA, ATA, AAPC, NADA) 
supported the use of VSLs as an input to the GEM, but requested 
clarification of what the specific requirements would be to ensure the 
VSL setting would not be capable of being easily overridden. Cummins 
and Daimler requested that the final rules explicitly allow vehicle 
manufacturers to access and adjust the VSL control feature for setting 
the maximum governed speed, arguing that the diverse needs of the 
commercial vehicle industry warrant flexibility in electronic control 
features, and that otherwise supply chain issues \91\ may result from 
the use of VSLs. NADA and EMA/TMA also requested that VSLs have 
override features and be adjustable, citing various needs for 
flexibility by the fleets. EMA/TMA and ATA requested that VSLs be 
adjustable downward by fleets in order to obtain greater benefit in 
GEM, if company policies change or if a subsequent vehicle owner needs 
a different VSL setting. EMA/TMA stated that the agencies should 
prohibit tampering with VSLs, and both EMA and TRALA requested more 
information on how the agencies intended to address tampering with 
VSLs.
---------------------------------------------------------------------------

    \91\ Commenters stated that OEMs need access for setting 
appropriate trims for managing the VSL, otherwise significant supply 
chain issues could result such as parts shortages caused by the need 
for unique speed governed PCMs.
---------------------------------------------------------------------------

    In addition to features governing the maximum vehicle speed, 
commenters requested adding other programmable flexibilities to 
mitigate potential drawbacks to VSLs. Cummins, DTNA,

[[Page 57155]]

and EMA/TMA requested that a programmable ``soft top'' speed be added 
to PCMs which would allow a vehicle to exceed the speed limit setting 
governed by a VSL for a short period of time. A ``soft top'' feature 
could be used for a limited duration in order to maneuver and pass 
other on-road vehicles at speeds greater than that governed by the VSL. 
The commenters argued this was important for vehicle passing and 
safety-related situations where, without a soft top feature, it could 
be possible for speed limited trucks to obstruct other vehicles on the 
road and cause severe road congestion.
    ATA and EMA/TMA also requested that manufacturers be allowed to 
program a mileage based expiration into the VSL control feature, in 
order to preserve the value of vehicles for second owners who may 
require operation at higher speeds. ATA further commented that 
manufacturers should be allowed to account for additional GEM input 
benefits if the speed governor is reprogrammed to a lower speed within 
the useful life of the vehicle.
    After carefully considering the comments, the agencies have 
decided, for these final rules, to retain most of the elements in the 
proposal. Manufacturers will be allowed to implement a fixed maximum 
governed vehicle speed through a VSL feature and to use the maximum 
governed vehicle speed as an input to the GEM for certification. Also 
consistent with the proposal, the agencies are not premising the final 
standards on the use of VSLs. The comments received from stakeholders 
did not address the agencies' concerns discussed in the proposal, 
specifically the risk of requiring VSL in situations that are not 
appropriate from an efficiency perspective because it may lead to 
additional vehicle trips to deliver the same amount of freight.\92\ The 
agencies continue to believe that we are not in a position to determine 
how many additional vehicles would benefit from the use of a VSL with a 
setting of less than 65 mph (a VSL with a speed set at or above 65 mph 
will show no CO2 emissions or fuel consumption benefit on 
the drive cycles included in this program). The agencies further 
believe that manufacturers will not utilize VSLs unless it is in their 
interest to do so, so that these unintended consequences should not 
occur when manufacturers use VSLs as a compliance strategy. We will 
monitor the industry's use of VSL in this program and may consider 
using this technology in standard setting in the future.
---------------------------------------------------------------------------

    \92\ See 75 FR at page 74223.
---------------------------------------------------------------------------

    The agencies have decided to adopt commenters' suggestions to allow 
adjustable lower limits that can be set and governed by VSLs 
independent of the one governing the maximum certified speed limit to 
provide the desired flexibility requested by the trucking industry. We 
believe that this flexibility would not decrease the anticipated fuel 
consumption or CO2 benefits of VSLs because the adjustable 
limits would be lower values. Issues identified by the commenters 
including the ability to change delivery routes requiring lower 
governed speeds or when a fleet's business practices change resulting 
in a desire for greater fuel consumption savings are not in conflict 
with the purpose and benefit of VSLs. As such, the agencies have 
decided to allow a manufacturer to install features for its fleet 
customers to set their own lower adjustable limits below the maximum 
VSL specified by the agencies. However, the agencies have decided to 
not allow any additional benefit in the GEM to a manufacturer for 
allowing a lower governed speed in-use than the certified maximum limit 
for this first phase of the HD National Program because we can only be 
certain that the VSL will be at the maximum setting.
    Both agencies also agree that manufacturers can provide a ``soft 
top'' and expiration features to be programmed into PCMs to provide 
additional flexibility for fleet owners and so that fleets who purchase 
used vehicles have the ability to have different VSL policies than the 
original owner of the vehicle. Although the agencies considered 
limiting the soft top maximum level due to safety and fuel consumption/
GHG benefit concerns, we have decided to allow the soft top maximum 
level to be set to any level higher than the maximum speed governed by 
the VSL. This approach will provide drivers with the ability to better 
navigate through traffic. However, the agencies are requiring that 
manufacturers providing a soft top feature must design the system so it 
cannot be modified by the fleets and will not decrement the vehicle 
speed limit causing the vehicle to decelerate while the driver is 
operating a vehicle above the normal governed vehicle speed limit. For 
example, if a manufacturer designs a vehicle speed limiter that has a 
normal governed speed limiter setting of 62 mph, and a ``soft top'' 
speed limiter value of 65 mph, the algorithm shall not cause the 
vehicle speed to decrement causing the vehicle to decelerate while the 
driver is operating the vehicle at a speed greater that 62 mph (between 
62 and 65 mph). The agencies are concerned that a forced deceleration 
when a driver is attempting to pass or maneuver could have an adverse 
impact on safety.
    In using a soft top feature, a manufacturer will be required to 
provide to the agencies a functional description of the ``soft top'' 
control strategy including calibration values, the speed setting for 
both the hard limit and the soft top and the maximum time per day the 
control strategy could allow the vehicle to operate at the ``soft top'' 
speed limit at the time of certification. This information will be used 
to derive a factor to discount the VSL input used in the GEM to 
determine the fuel consumption and GHG emissions performance of the 
vehicle. The agencies also agree with comments that VSLs should be 
adjustable so as not to potentially limit a vehicle's resale value. 
However, manufacturers choosing the option to override the VSL after a 
specified number of miles would be required to discount the benefit of 
the VSL relative to the tractor's full lifetime miles. The VSL discount 
benefits for using soft-top and expiration features must be calculated 
using Equation II-1.\93\ Additional details regarding the derivation of 
the discounted equation are included in RIA Chapter 2. The agencies are 
also requiring that any vehicle that has a ``soft top'' VSL to identify 
the use of the ``soft top'' VSL on the vehicle emissions label.
---------------------------------------------------------------------------

    \93\ See Sec.  1037.640.
---------------------------------------------------------------------------

Equation II-1: Discounted Vehicle Speed Limiter Equation

VSL input for GEM = Expiration Factor * [Soft Top Factor* Soft Top VSL 
+ (1-Soft Top Factor) * VSL] + (1-Expiration Factor)*65 mph
    The agencies will require that the VSL algorithm be designed to 
assure that over the useful life of the vehicle that the vehicle will 
not operate in the soft top mode for more miles than would be expected 
based on the values used in Equation 0-1, as specified by the 
expiration factor and the soft top factor. In addition, any time the 
cumulative percentage of operation in the soft top mode (based on 
miles) exceeds the maximum ratio that could occur at the full lifetime 
mileage, or at the expiration mileage if used, the algorithm must not 
allow the vehicle to exceed the VSL value. In this case, the soft top 
feature remain disabled until the vehicle mileage reaches a point where 
the ratio no longer meets this condition.
    In response to the comments about how the agencies will evaluate

[[Page 57156]]

tampering, NHTSA and EPA have added a number of requirements in these 
final rules relating to the VSL control feature. VSL control features 
should be designed so they cannot be easily overridden. Manufacturers 
must ensure that the governed speed limit programmed into the VSL must 
also be verifiable through on-board diagnostic scanning tools, and must 
provide a description of the coding to identify the governed maximum 
speed limit and the expiration mileage both at the time of the initial 
vehicle certification and in-use. The agencies believe both 
manufacturers and fleets should work toward maintaining the integrity 
of VSLs, and the agencies may conduct new-vehicle and in-use random 
audits to verify that inputs into GEM are accurate.
    The agencies are aware that some fleets/owners make changes to 
vehicles, such as installing different diameter tires, changing the 
axle (final drive) ratio and transmission gearing, such that a vehicle 
could travel at speeds higher than the speed limited by its VSL. 
Vehicles subject to FMCSA requirements must be in compliance with 49 
CFR 393.82. The requirements apply to speedometers and states as 
follows:

    Each bus, truck, and truck-tractor must be equipped with a 
speedometer indicating vehicle speed in miles per hour and/or 
kilometers per hour. The speedometer must be accurate to within plus 
or minus 8 km/hr (5 mph) at a speed of 80 km/hr (50 mph).

    To facilitate adjustments for component changes affecting vehicle 
speed, manufacturers should provide a fleet/owner with the means to do 
so unless the adjustments would affect the VSL setting or operation.
    DTNA and ATA additionally requested that the agencies ensure that 
any VSL provisions adopted under the GHG emissions and fuel efficiency 
rules align with existing NHTSA standards. The agencies agree and note 
that there are no existing standards for a VSL outside of this current 
rulemaking activity. However, NHTSA has announced its intent to publish 
a proposal in 2012 for a VSL.\94\ While both agencies have taken steps 
to avoid potential conflicts between the rulemaking being finalized 
today for fuel consumption and GHG emissions and the anticipated safety 
rulemaking, different conclusions may be reached in a safety-based 
rulemaking on VSLs, particularly in the approach to specifying soft top 
parameters and VSL expiration.
---------------------------------------------------------------------------

    \94\ 76 FR 78.
---------------------------------------------------------------------------

(h) Defined Vehicle Configurations in the GEM
    As discussed above, the agencies are adopting methodologies that 
manufacturers will use to quantify the values input into the GEM for 
these factors affecting vehicle efficiency: Coefficient of Drag, Tire 
Rolling Resistance Coefficient, Weight Reduction, Vehicle Speed 
Limiter, and Extended Idle Reduction Technology. The other aspects of 
the vehicle configuration are fixed within the model and are not varied 
for the purpose of compliance. The defined inputs include the tractor-
trailer combination curb weight, payload, engine characteristics, and 
drivetrain for each vehicle type, and others.
(i) Vehicle Drive Cycles
    The GEM simulation model uses various inputs to characterize a 
vehicle's configuration (such as weight, aerodynamics, and rolling 
resistance) and predicts how the vehicle would behave on the road when 
it follows a driving cycle (vehicle speed versus time). As noted by the 
2010 NAS Report,\95\ the choice of a drive cycle used in compliance 
testing has significant consequences on the technology that will be 
employed to achieve a standard as well as the ability of the technology 
to achieve real world reductions in emissions and improvements in fuel 
consumption. Manufacturers naturally will design vehicles to ensure 
they satisfy regulatory standards. An ill-suited drive cycle for a 
regulatory category could encourage GHG emissions and fuel consumption 
technologies which satisfy the test but do not achieve the same 
benefits in use. For example, requiring all trucks to use a constant 
speed highway drive cycle will drive significant aerodynamic 
improvements. However, in the real world a combination tractor used for 
local delivery may spend little time on the highway, reducing the 
benefits achieved by this technology. In addition, the extra weight of 
the aerodynamic fairings will actually penalize the GHG and fuel 
consumption performance in urban driving and may reduce the freight 
carrying capability. The unique nature of the kinds of CO2 
emissions control and fuel consumption technology means that the same 
technology can be of benefit during some operation but cause a reduced 
benefit under other operation.\96\ To maximize the GHG emissions and 
fuel consumption benefits and avoid unintended reductions in benefits, 
the drive cycle should focus on promoting technology that produces 
benefits during the primary operation modes of the application. 
Consequently, drive cycles used in GHG emissions and fuel consumption 
compliance testing should reasonably represent the primary actual use, 
notwithstanding that every vehicle has a different drive cycle in-use.
---------------------------------------------------------------------------

    \95\ See 2010 NAS Report, Note 21, Chapters 4 and 8.
    \96\ This situation does not typically occur for heavy-duty 
emission control technology designed to control criteria pollutants 
such as PM and NOX.
---------------------------------------------------------------------------

    The agencies proposed a modified version of the California ARB 
Heavy Heavy-duty Truck 5 Mode Cycle \97\, using the basis of three of 
the cycles which best mirror Class 7 and 8 combination tractor driving 
patterns, based on information from EPA's MOVES model.\98\ The key 
advantage of the California ARB 5 mode cycle is that it provides the 
flexibility to use several different modes and weight the modes to fit 
specific vehicle application usage patterns. For the proposal, EPA 
analyzed the five cycles and found that some modifications to the 
cycles were required to allow sufficient flexibility in weightings. The 
agencies proposed the use of the Transient mode, as defined by 
California ARB, because it broadly covers urban driving. The agencies 
also proposed altered versions of the High Speed Cruise and Low Speed 
Cruise modes which reflected only constant speed cycles at 65 mph and 
55 mph respectively. In the NPRM, the agencies proposed to use three 
cycles which were the ARB transient cycle, a 55 mph steady state 
cruise, and a 65 mph steady state cruise.
---------------------------------------------------------------------------

    \97\ California Air Resources Board. Heavy Heavy-duty Diesel 
Truck chassis dynamometer schedule, Transient Mode. Last accessed on 
August 2, 2010 at http://www.dieselnet.com/standards/cycles/hhddt.html.
    \98\ EPA's MOVES (Motor Vehicle Emission Simulator). See http://www.epa.gov/otaq/models/moves/index.htm for additional information.
---------------------------------------------------------------------------

    The agencies received comment from NACAA recommending an increase 
in the high speed cruise cycle speed from the proposed value of 65 mph 
to 75 mph because trucks travel at higher speeds. The agencies analyzed 
the urban and rural interstate truck speed limits in each state to 
determine the national average truck speed limit. State interstate 
speed limits for trucks vary between 55 and 75 mph, depending on the 
state.\99\ Based on this information, the national median truck speed 
limit is

[[Page 57157]]

65 mph. The agencies also analyzed the national average truck speed 
limit weighted by VMT for each state based on VMT data by state from 
the Federal Highway Administration as described in RIA Section 3.4.2. 
Based on this information, the national average VMT-weighted truck 
speed limit is 63 mph. The agencies continue to believe that the 
appropriate high speed cruise speed should be set at the national 
average truck speed limit to appropriately balance the evaluation of 
technologies such as aerodynamics, but not overstate the benefits of 
these technologies. Therefore, the agencies are adopting as proposed a 
speed of 65 mph for the high speed cruise cycle.
---------------------------------------------------------------------------

    \99\ Governors Highway Safety Association. Speed Limit Laws May 
2011. Last viewed on May 9, 2011 at http://www.ghsa.org/html/stateinfo/laws/speedlimit_laws.html.
---------------------------------------------------------------------------

    The agencies also received comments from Allison which disagreed 
with proposed drive cycles for combination tractors because the cycles 
did not account for external factors such as grades, wind, traffic 
condition, etc. Allison also believes that the acceleration rates are 
too low. The agencies recognize that the proposed drive cycles do not 
incorporate the external factors described by Allison. Parallel to the 
approach used to evaluate light-duty vehicles, the drive cycles do not 
incorporate either grade or wind which can be difficult to simulate in 
chassis dynamometer cells. In the final rules, the agencies are 
defining an approach that manufacturers may take to evaluate their 
aerodynamic packages in a wind-averaged condition and use a modified Cd 
value in GEM.\100\ The agencies are also adopting provisions for the 
innovative technology demonstration that allows for the use of on-road 
testing which includes grades for technologies whose benefits are 
reflected with grade. Lastly, the agencies' final drive cycles for 
highway operation contain a constant speed, as proposed. The 
acceleration and deceleration rates are only used to bring the vehicle 
to the cruising speed and the CO2 emissions and fuel 
consumption from these portions of the drive cycle are not included in 
the composite emissions and fuel consumption results. The agencies did 
not include the speed dithering, which is representative of actual 
driving and traffic conditions, in the proposed constant speed portion 
of the cycles because the dithering does not provide any additional 
distinction between technologies but only added complexity to the 
cycle. The agencies believe this approach is still appropriate for the 
final action.
---------------------------------------------------------------------------

    \100\ See Section IV.B.3.b below.
---------------------------------------------------------------------------

    Allison referred the agencies to the Oak Ridge National Laboratory 
and SmartWay program to review the amount of time long-haul vehicles 
spend on the highway. They believe the steady state highway speeds are 
overestimated. Data provided by Allison indicates that day cabs spend 
only 14 percent of miles traveling at speeds greater than 60 mph. NHTSA 
and EPA recognize that there is a variation in the amount of miles day 
cabs travel under different operations. As described above, the 
agencies are adopting an approach where tractors which operate like 
vocational vehicles may be regulated as such in the HD program. Thus, 
these day cabs will have a drive cycle weighting representative of 
vocational vehicles with more weighting on the transient operation and 
less on the highway speed operation.
    For proposal, EPA and NHTSA relied on the EPA MOVES analysis of 
Federal Highway Administration data to develop the mode weightings to 
characterize typical operations of heavy-duty trucks, per Table II-10 
below.\101\ A detailed discussion of drive cycles is included in RIA 
Chapter 3.\102\ The agencies are adopting the proposed drive cycle 
weightings for combination tractors.
---------------------------------------------------------------------------

    \101\ The Environmental Protection Agency. Draft MOVES2009 
Highway Vehicle Population and Activity Data. EPA-420-P-09-001, 
August 2009 http://www.epa.gov/otaq/models/moves/techdocs/420p09001.pdf.
    \102\ In the light-duty vehicle rule, EPA and NHTSA based 
compliance with tailpipe standards on use of the FTP and HFET, and 
declined to use alternative tests. See 75 FR 25407. NHTSA is 
mandated to use the FTP and HFET tests for CAFE standards, and all 
relevant data was obtained by FTP and HFET testing in any case. Id. 
Neither of these constraints exists for Class 7-8 tractors. The 
little data which exist on current performance are principally 
measured by the ARB Heavy Heavy-duty Truck 5 Mode Cycle testing, and 
NHTSA is not mandated to use the FTP to establish heavy-duty fuel 
economy standards. See 49 U.S.C. 32902(k)(2) authorizing NHTSA, 
among other things, to adopt and implement appropriate ``test 
methods, measurement metrics, * * * and compliance protocols''.

                Table II-10--Drive Cycle Mode Weightings
------------------------------------------------------------------------
                                                   55 mph       65 mph
                                    Transient      cruise       cruise
------------------------------------------------------------------------
Day Cabs.........................          19%          17%          64%
Sleeper Cabs.....................           5%           9%          86%
------------------------------------------------------------------------

(ii) Standardized Trailers
    As proposed, NHTSA and EPA are adopting provisions so that the 
tractor performance in the GEM is judged assuming the tractor is 
pulling a standardized trailer. The agencies did not receive any 
adverse comments related to this approach. The agencies believe that an 
assessment of the tractor fuel consumption and CO2 emissions 
should be conducted using a tractor-trailer combination. We believe 
this approach best reflects the impact of the overall weight of the 
tractor-trailer and the aerodynamic technologies in actual use, where 
tractors are designed and used with a trailer. The GEM will continue to 
use a predefined typical trailer in assessing overall performance. The 
high roof sleeper cabs are paired with a standard box trailer; the mid 
roof tractors are paired with a tanker trailer; and the low roof 
tractors are paired with a flat bed trailer.
(iii) Empty Weight and Payload
    The total weight of the tractor-trailer combination is the sum of 
the tractor curb weight, the trailer curb weight, and the payload. The 
total weight of a vehicle is important because it in part determines 
the impact of technologies, such as rolling resistance, on GHG 
emissions and fuel consumption. In this final action, the agencies are 
specifying each of these aspects of the vehicle, as proposed.
    In use, trucks operate at different weights at different times 
during their operations. The greatest freight transport efficiency (the 
amount of fuel required to move a ton of payload) would be achieved by 
operating trucks at the maximum load for which they are designed all of 
the time. However, logistics such as delivery demands which require 
that trucks travel without full loads, the density of payload, and the 
availability of full loads of freight limit the ability of trucks to 
operate at their highest efficiency all the time. M.J. Bradley analyzed 
the Truck Inventory and Use Survey and found that

[[Page 57158]]

approximately 9 percent of combination tractor miles travelled empty, 
61 percent are ``cubed-out'' (the trailer is full before the weight 
limit is reached), and 30 percent are ``weighed out'' (operating weight 
equal 80,000 pounds which is the gross vehicle weight limit on the 
Federal Interstate Highway System or greater than 80,000 pounds for 
vehicles traveling on roads outside of the interstate system).\103\
---------------------------------------------------------------------------

    \103\ M.J. Bradley & Associates. Setting the Stage for 
Regulation of Heavy-Duty Vehicle Fuel Economy and GHG Emissions: 
Issues and Opportunities. February 2009. Page 35. Analysis based on 
1992 Truck Inventory and Use Survey data, where the survey data 
allowed developing the distribution of loads instead of merely the 
average loads.
---------------------------------------------------------------------------

    As described above, the amount of payload that a tractor can carry 
depends on the category (or GVWR and GCWR) of the vehicle. For example, 
a typical Class 7 tractor can carry less payload than a Class 8 
tractor. For proposal, the agencies used the Federal Highway 
Administration Truck Payload Equivalent Factors using Vehicle Inventory 
and Use Survey (VIUS) and Vehicle Travel Information System data to 
determine the proposed payloads. FHWA's results found that the average 
payload of a Class 8 vehicle ranged from 36,247 to 40,089 pounds, 
depending on the average distance travelled per day.\104\ The same 
results found that Class 7 vehicles carried between 18,674 and 34,210 
pounds of payload also depending on average distance travelled per day. 
Based on this data, the agencies proposed to prescribe a fixed payload 
of 25,000 pounds for Class 7 tractors and 38,000 pounds for Class 8 
tractors for their respective test procedures. The agencies proposed a 
common payload for Class 8 day cabs and sleeper cabs as predefined GEM 
input because the data available do not distinguish based on type of 
Class 8 tractor. These payload values represent a heavily loaded 
trailer, but not maximum GVWR, since as described above the majority of 
tractors ``cube-out'' rather than ``weigh-out.''
---------------------------------------------------------------------------

    \104\ The U.S. Federal Highway Administration. Development of 
Truck Payload Equivalent Factor. Table 11. Last viewed on March 9, 
2010 at http://ops.fhwa.dot.gov/freight/freight_analysis/faf/faf2_reports/reports9/s510_11_12_tables.htm.
---------------------------------------------------------------------------

    The agencies developed the proposed tractor curb weight inputs from 
actual tractor weights measured in two of EPA's test programs and based 
on information from the manufacturers. The proposed trailer curb weight 
inputs were derived from actual trailer weight measurements conducted 
by EPA and weight data provided to ICF International by the trailer 
manufacturers.\105\
---------------------------------------------------------------------------

    \105\ ICF International. Investigation of Costs for Strategies 
to Reduce Greenhouse Gas Emissions for Heavy-Duty On-road Vehicles. 
July 2010. Pages 4-15. Docket Number EPA-HQ-OAR-2010-0162-0044.
---------------------------------------------------------------------------

    The agencies received comments from UMTRI and ATA regarding the 
values assumed for the combination tractor weights. UMTRI recommended 
using 80,000 pounds for the total weight for tractor-trailer 
combinations. ATA based on their analysis of the Federal Highway 
Administration's Long Term Pavement Database, recommended 5,000 to 
10,000 pound payload for Class 7 tractors and 25,000 to 30,000 pounds 
for Class 8 tractors. ATA also determined from the same database that 
20 percent of tractor miles are empty, 67 percent cube-out, and 13 
percent weigh-out. The agencies are adopting the proposed tractor-
trailer weights because we do not have strong evidence to select other 
values and because changing the assumed values would not change the 
impact on GHG emissions or fuel consumption of the technologies 
included in this phase of the HD program (the relative stringency of 
the standards and the projected emission reductions do not change with 
assumed payload). NHTSA and EPA intend to continue evaluating 
additional sources of weight information in future phases of the 
program.
    Details of the final individual weight inputs by regulatory 
category, as shown in Table II-11, are included in RIA Chapter 3.

                                 Table II-11--Final Combination Tractor Weights
----------------------------------------------------------------------------------------------------------------
                                                                Tractor      Trailer                    Total
             Model type               Regulatory subcategory  tare weight     weight      Payload       weight
                                                                 (lbs)        (lbs)        (lbs)        (lbs)
----------------------------------------------------------------------------------------------------------------
Class 8.............................  Sleeper Cab High Roof.       19,000       13,500       38,000       70,500
Class 8.............................  Sleeper Cab Mid Roof..       18,750       10,000       38,000       66,750
Class 8.............................  Sleeper Cab Low Roof..       18,500       10,500       38,000       67,000
Class 8.............................  Day Cab High Roof.....       17,500       13,500       38,000       69,000
Class 8.............................  Day Cab Mid Roof......       17,100       10,000       38,000       65,100
Class 8.............................  Day Cab Low Roof......       17,000       10,500       38,000       65,500
Class 7.............................  Day Cab High Roof.....       11,500       13,500       25,000       50,000
Class 7.............................  Day Cab Mid Roof......       11,100       10,000       25,000       46,100
Class 7.............................  Day Cab Low Roof......       11,000       10,500       25,000       46,500
----------------------------------------------------------------------------------------------------------------

(iv) Standardized Drivetrain
    The agencies' assessment at proposal of the current vehicle 
configuration process at the truck dealer's level was that the truck 
companies provide tools to specify the proper drivetrain matched to the 
buyer's specific circumstances. These dealer tools allow a significant 
amount of customization for drive cycle and payload to provide the best 
specification for each individual customer. The agencies are not 
seeking to disrupt this process. Optimal drivetrain selection is 
dependent on the engine, drive cycle (including vehicle speed and road 
grade), and payload. Each combination of engine, drive cycle, and 
payload has a single optimal transmission and final drive ratio. The 
agencies received comments from ArvinMeritor and ICCT which suggested 
that the agencies incorporate the actual drivetrain configuration (axle 
configuration, driveline efficiency, and transmission) into the GEM. 
The agencies continue to believe, and therefore are adopting as 
proposed, that it is appropriate to specify the engine's fuel 
consumption map, drive cycle, and payload; therefore, it makes sense to 
also specify the drivetrain that matches.
(v) Engine Input to the GEM for Tractors
    As proposed, the agencies are defining the engine characteristics 
used in the GEM, including the fuel consumption map which provides the 
fuel consumption at hundreds of engine speed and torque points. If the 
agencies did not standardize the fuel map, then a tractor that uses an 
engine with emissions and fuel consumption better than the standards 
would require fewer vehicle reductions than those technically feasible 
reductions reflected in the final standards. The agencies are 
finalizing two distinct fuel consumption maps for use in the GEM. The 
first fuel

[[Page 57159]]

consumption map would be used in the GEM for the 2014 through 2016 
model years and represents an average engine which meets EPA's final 
2014 model year engine CO2 emissions standards. The same 
fuel map would be used for NHTSA's voluntary standards in the 2014 and 
2015 model years, as well as its mandatory program in the 2016 model 
year. A second fuel consumption map will be used beginning in the 2017 
model year and represents an engine which meets the 2017 model year 
CO2 emissions and fuel consumption standards and accounts 
for the increased stringency in the final MY 2017 standard. The 
agencies have modified the 2017 MY fuel map used in the GEM for the 
final rulemaking to address comments received. Details regarding this 
change can be found in RIA Chapter 4.4.4. Effectively there is no 
change in stringency of the tractor vehicle (not including the engine 
standards over the full rulemaking period).\106\ These inputs are 
appropriate given the separate regulatory requirement that Class 7 and 
8 combination tractor manufacturers use only certified engines.
---------------------------------------------------------------------------

    \106\ As noted earlier, use of the 2017 model year fuel 
consumption map as a GEM input results in numerically more stringent 
final vehicle standards for MY 2017.
---------------------------------------------------------------------------

(i) Heavy-Duty Engine Test Procedure for Engines Installed in 
Combination Tractors
    The HD engine test procedure consists of two primary aspects--a 
duty cycle and a metric to evaluate the emissions and fuel consumption.
    EPA proposed that the GHG emission standards for heavy-duty engines 
under the CAA would be expressed as g/bhp-hr while NHTSA's proposed 
fuel consumption standards under EISA, in turn, be represented as gal/
100 bhp-hr. The NAS panel did not specifically discuss or recommend a 
metric to evaluate the fuel consumption of heavy-duty engines. However, 
as noted above they did recommend the use of a load-specific fuel 
consumption metric for the evaluation of vehicles.\107\ An analogous 
metric for engines is the amount of fuel consumed per unit of work. The 
g/bhp-hr metric is also consistent with EPA's current standards for 
non-GHG emissions for these engines. The agencies did not receive any 
adverse comments related to the metrics for HD engines; therefore, we 
are adopting the metrics as proposed.
---------------------------------------------------------------------------

    \107\ See NAS Report, Note 21, at page 39.
---------------------------------------------------------------------------

    The agencies believe it is appropriate to set standards based on a 
single test procedure, either the Heavy-duty FTP or SET, depending on 
the primary expected use of the engine. This approach differs from 
EPA's criteria pollutant standards for engines which currently require 
that manufacturers demonstrate compliance over the transient FTP cycle; 
over the steady-state SET procedure; and during not-to-exceed testing. 
EPA created this multi-layered approach to criteria emissions control 
in response to engine designs that optimized operation for lowest fuel 
consumption at the expense of very high criteria emissions when 
operated off the regulatory cycle. EPA's use of multiple test 
procedures for criteria pollutants helps to ensure that manufacturers 
calibrate engine systems for compliance under all operating conditions. 
We are not concerned if manufacturers further calibrate engines off-
cycle to give better in-use fuel consumption while maintaining 
compliance with the criteria emissions standards as such calibration is 
entirely consistent with the goals of our joint program. Further, we 
believe that setting GHG and fuel consumption standards based on both 
transient and steady-state operating conditions for all engines could 
lead to undesirable outcomes.
    It is critical to set standards based on the most representative 
test cycles in order for performance in-use to obtain the intended (and 
feasible) air quality and fuel consumption benefits. Tractors spend the 
majority of their operation at steady state conditions, and will obtain 
in-use benefit of technologies such as turbocompounding and other waste 
heat recovery technologies during this kind of typical engine 
operation. Turbocompounding is a very effective approach to lower fuel 
consumption under steady driving conditions typified by combination 
tractor trailer operation and is well reflected in testing over the SET 
test procedure. However, when used in driving typified by transient 
operation as we expect for vocational vehicles and as is represented by 
the Heavy-duty FTP, turbocompounding shows very little benefit. Setting 
an emission standard based on the Heavy-duty FTP for engines intended 
for use in combination tractor trailers could lead manufacturers to not 
apply turbocompounding even though it can be a highly cost effective 
means to reduce GHG emissions and lower fuel consumption. (It is for 
this reason that turbocompounding is not part of the technology basis 
for MHD or HHD engines installed in vocational vehicles.)
    The agencies proposed that engines installed in tractors 
demonstrate compliance with the CO2 emissions and fuel 
consumption standards over the SET cycle. Commenters such as Cummins, 
Bosch, Daimler, and Honeywell supported the proposed approach. ACEEE 
recommended adopting a new test cycle, such as the World Harmonized 
Duty Cycle which was developed using newer data, to evaluate HD 
engines. Daimler also supported the WHDC for future phases of the 
program. The agencies continue to believe the important issues and 
technical work related to setting new criteria pollutant emissions 
standards appropriate for the World Harmonized Duty Cycle are 
significant and beyond the scope of this rulemaking. The SET cycle 
remains representative of typical driving cycles for combination 
tractors (and engines installed in them). Therefore, the agencies are 
adopting the SET cycle to evaluate CO2 emissions and fuel 
consumption of HD engines installed in tractors, as proposed.
    The current non-GHG emissions engine test procedures also require 
the development of regeneration emission rates and frequency factors to 
account for the emission changes during a regeneration event (40 CFR 
86.004-28). EPA and NHTSA proposed not to include these emissions from 
the calculation of the compliance levels over the defined test 
procedures. Cummins and Daimler supported this approach and stated that 
sufficient incentives already exist for manufacturers to limit 
regeneration frequency. Conversely, Volvo opposed the omission of IRAF 
requirements for CO2 emissions because emissions from 
regeneration can be a significant portion of the expected improvement 
and a significant variable between manufacturers
    At proposal, we considered including regeneration in the estimate 
of fuel consumption and GHG emissions and decided not to do so for two 
reasons. See 75 FR at 74188. First, EPA's existing criteria emission 
regulations already provide a strong motivation to engine manufacturers 
to reduce the frequency and duration of infrequent regeneration events. 
The very stringent 2010 NOX emission standards cannot be met 
by engine designs that lead to frequent and extend regeneration events. 
Hence, we believe engine manufacturers are already reducing 
regeneration emissions to the greatest degree possible. In addition to 
believing that regenerations are already controlled to the extent 
technologically possible, we believe that attempting to include 
regeneration emissions in the standard setting could lead to an 
inadvertently lax emissions standard. In order to include regeneration 
and set appropriate standards, EPA and NHTSA would have needed to 
project the regeneration

[[Page 57160]]

frequency and duration of future engine designs in the time frame of 
this program. Such a projection would be inherently difficult to make 
and quite likely would underestimate the progress engine manufacturers 
will make in reducing infrequent regenerations. If we underestimated 
that progress, we would effectively be setting a more lax set of 
standards than otherwise would be expected. Hence in setting a standard 
including regeneration emissions we faced the real possibility that we 
would achieve less effective CO2 emissions control and fuel 
consumption reductions than we will achieve by not including 
regeneration emissions. Therefore, the agencies are finalizing an 
approach as proposed which does not include the regenerative emissions.
(j) Chassis-Based Test Procedure
    In the proposal, the agencies considered proposing a chassis-based 
vehicle test to evaluate Class 7 and 8 tractors based on a laboratory 
test of the engine and vehicle together. A ``chassis dynamometer test'' 
for heavy-duty vehicles would be similar to the Federal Test Procedure 
used today for light-duty vehicles.
    However, the agencies decided not to propose the use of a chassis 
test procedure to demonstrate compliance for tractor standards due to 
the significant technical hurdles to implementing such a program by the 
2014 model year. The agencies recognize that such testing requires 
expensive, specialized equipment that is not yet widespread within the 
industry. The agencies have only identified approximately 11 heavy-duty 
chassis sites in the United States today and rapid installation of new 
facilities to comply with model year 2014 is not possible.\108\
---------------------------------------------------------------------------

    \108\ For comparison, engine manufacturers typically own a large 
number of engine dynamometer test cells for engine development and 
durability (up to 100 engine dynamometers per manufacturer).
---------------------------------------------------------------------------

    In addition, and of equal if not greater importance, because of the 
enormous numbers of vehicle configurations that have an impact on fuel 
consumption, we do not believe that it would be reasonable to require 
testing of many combinations of tractor model configurations on a 
chassis dynamometer. The agencies evaluated the options available for 
one tractor model (provided as confidential business information from a 
truck manufacturer) and found that the company offered three cab 
configurations, six axle configurations, five front axles, 12 rear 
axles, 19 axle ratios, eight engines, 17 transmissions, and six tire 
sizes--where each of these options could impact the fuel consumption 
and CO2 emissions of the tractor. Even using representative 
grouping of tractors for purposes of certification, this presents the 
potential for many different combinations that would need to be tested 
if a standard were adopted based on a chassis test procedure.
    The agencies received comments from ACEEE and UCS supporting a full 
vehicle testing approach, but these commenters recognized the 
difficulties in doing this in the first phase of the HD program. The 
agencies maintain that the full vehicle testing on chassis dynamometers 
is not feasible in the timeframe of this rulemaking, although we 
believe such an approach may be appropriate in the future, if more 
testing facilities become available and if the agencies are able to 
address the complexity of tractor configurations issue described above.
(4) Summary of Flexibility and Credit Provisions for Tractors and 
Engine Used in These Tractors
    EPA and NHTSA are finalizing four flexibility provisions 
specifically for heavy-duty tractor and engine manufacturers, as 
discussed in Section IV below. These are an averaging, banking and 
trading program for emissions and fuel consumption credits, as well as 
provisions for early credits, advanced technology credits, and credits 
for innovative vehicle or engine technologies which are not included as 
inputs to the GEM or are not demonstrated on the engine SET test cycle. 
With the exception of the advanced technology credits, credits 
generated under these provisions can only be used within the same 
averaging set which generated the credit (for example, credits 
generated by HD engines installed in tractors can only be used by HD 
engines). EPA is also adopting a N2O emission credit 
program, as described in Section IV below.
(5) Deferral of Standards for Tractor and Engine Manufacturing 
Companies That Are Small Businesses
    EPA and NHTSA are not adopting greenhouse gas emissions and fuel 
consumption standards for small tractor or engine manufacturers meeting 
the Small Business Administration (SBA) size criteria of a small 
business as described in 13 CFR 121.201.\109\ The agencies will instead 
consider appropriate GHG and fuel consumption standards for these 
entities as part of a future regulatory action. This includes both 
U.S.-based and foreign small volume heavy-duty tractor and engine 
manufacturers.
---------------------------------------------------------------------------

    \109\ See Sec.  1036.150 and Sec.  1037.150.
---------------------------------------------------------------------------

    The agencies have identified two entities that fit the SBA size 
criterion of a small business.\110\ The agencies estimate that these 
small entities comprise less than 0.5 percent of the total heavy-duty 
combination tractors in the United States based on Polk Registration 
Data from 2003 through 2007,\111\ and therefore that the exemption will 
have a negligible impact on the GHG emissions and fuel consumption 
improvements from the final standards.
---------------------------------------------------------------------------

    \110\ The agencies have identified Ottawa Truck, Inc. and Kalmar 
Industries USA as two potential small tractor manufacturers.
    \111\ M.J. Bradley. Heavy-duty Vehicle Market Analysis. May 
2009.
---------------------------------------------------------------------------

    To ensure that the agencies are aware of which companies would be 
exempt, we are requiring that such entities submit a declaration to EPA 
and NHTSA containing a detailed written description of how that 
manufacturer qualifies as a small entity under the provisions of 13 CFR 
121.201.

C. Heavy-Duty Pickup Trucks and Vans

    The primary elements of the EPA and NHTSA programs for complete HD 
pickups and vans are presented in this section. These provisions also 
cover optional chassis certification of incomplete HD vehicles and of 
Class 4 and 5 vehicles, as discussed in detail in Section V.B(1)(e). 
Section II.C(1) explains the form of the CO2 and fuel 
consumption standards, the numerical levels for those standards, and 
the approach to phasing in the standards over time. The measurement 
procedure for determining compliance is discussed in Section II.C(2), 
and the EPA and NHTSA compliance programs are discussed in Section 
II.C(3). Section II.C(4) discusses implementation flexibility 
provisions. Section II.E discusses additional standards and provisions 
for N2O and CH4 emissions, for vehicle air 
conditioning leakage, and for ethanol-fueled and electric vehicles. HD 
pickup and van air conditioning efficiency is not being regulated, for 
reasons discussed in Section II.E.
(1) What are the levels and timing of HD pickup and van standards?
(a) Vehicle-Based Standards
    About 90 percent of Class 2b and 3 vehicles are pickup trucks, 
passenger vans, and work vans that are sold by the original equipment 
manufacturers as complete vehicles, ready for use on the road. In 
addition, most of these

[[Page 57161]]

complete HD pickups and vans are covered by CAA vehicle emissions 
standards for criteria pollutants today (i.e., they are chassis tested 
similar to light-duty), expressed in grams per mile. This distinguishes 
this category from other, larger heavy-duty vehicles that typically 
have only the engines covered by CAA engine emission standards, 
expressed in grams per brake horsepower-hour. As a result, Class 2b and 
3 complete vehicles share much more in common with light-duty trucks 
than with other heavy-duty vehicles.
    Three of these commonalities are especially significant: (1) Over 
95 percent of the HD pickups and vans sold in the United States are 
produced by Ford, General Motors, and Chrysler--three companies with 
large light-duty vehicle and light-duty truck sales in the United 
States, (2) these companies typically base their HD pickup and van 
designs on higher sales volume light-duty truck platforms and 
technologies, often incorporating new light-duty truck design features 
into HD pickups and vans at their next design cycle, and (3) at this 
time most complete HD pickups and vans are certified to vehicle-based 
rather than engine-based EPA standards. There is also the potential for 
substantial GHG and fuel consumption reductions from vehicle design 
improvements beyond engine changes (such as through optimizing 
aerodynamics, weight, tires, and accessories), and the manufacturer is 
generally responsible for both engine and vehicle design. All of these 
factors together suggest that it is appropriate and reasonable to set 
standards for the vehicle as a whole, rather than to establish separate 
engine and vehicle GHG and fuel consumption standards, as is being done 
for the other heavy-duty categories. This approach for complete 
vehicles is consistent with Recommendation 8-1 of the NAS Report, which 
encourages the regulation of ``the final stage vehicle manufacturers 
since they have the greatest control over the design of the vehicle and 
its major subsystems that affect fuel consumption.'' There was 
consensus in the public comments supporting this approach.
(b) Work-Based Attributes
    In setting heavy-duty vehicle standards it is important to take 
into account the great diversity of vehicle sizes, applications, and 
features. That diversity reflects the variety of functions performed by 
heavy-duty vehicles, and this in turn can affect the kind of technology 
that is available to control emissions and reduce fuel consumption, and 
its effectiveness. EPA has dealt with this diversity in the past by 
making weight-based distinctions where necessary, for example in 
setting HD vehicle standards that are different for vehicles above and 
below 10,000 lb GVWR, and in defining different standards and useful 
life requirements for light-, medium-, and heavy-heavy-duty engines. 
Where appropriate, distinctions based on fuel type have also been made, 
though with an overall goal of remaining fuel-neutral.
    The joint EPA GHG and NHTSA fuel economy rules for light-duty 
vehicles accounted for vehicle diversity in that segment by basing 
standards on vehicle footprint (the wheelbase times the average track 
width). Passenger cars and light trucks with larger footprints are 
assigned numerically higher target levels for GHGs and numerically 
lower target levels for fuel economy in acknowledgement of the 
differences in technology as footprint gets larger, such that vehicles 
with larger footprints have an inherent tendency to burn more fuel and 
emit more GHGs per mile of travel. Using a footprint-based attribute to 
assign targets also avoids interfering with the ability of the market 
to offer a variety of products to maintain consumer choice.
    In developing this rulemaking, the agencies emphasized creating a 
program structure that would achieve reductions in fuel consumption and 
GHGs based on how vehicles are used and on the work they perform in the 
real world, consistent with the NAS report recommendations to be 
mindful of HD vehicles' unique purposes. Despite the HD pickup and van 
similarities to light-duty vehicles, we believe that the past practice 
in EPA's heavy-duty program of using weight-based distinctions in 
dealing with the diversity of HD pickup and van products is more 
appropriate than using vehicle footprint. Work-based measures such as 
payload and towing capability are key among the things that 
characterize differences in the design of vehicles, as well as 
differences in how the vehicles will be used. Vehicles in this category 
have a wide range of payload and towing capacities. These work-based 
differences in design and in-use operation are the key factors in 
evaluating technological improvements for reducing CO2 
emissions and fuel consumption. Payload has a particularly important 
impact on the test results for HD pickup and van emissions and fuel 
consumption, because testing under existing EPA procedures for criteria 
pollutants is conducted with the vehicle loaded to half of its payload 
capacity (rather than to a flat 300 lb as in the light-duty program), 
and the correlation between test weight and fuel use is strong.\112\
---------------------------------------------------------------------------

    \112\ Section II.C(2) discusses our decision that GHGs and fuel 
consumption for HD pickups and vans be measured using the same test 
conditions as in the existing EPA program for criteria pollutants.
---------------------------------------------------------------------------

    Towing, on the other hand, does not directly factor into test 
weight as nothing is towed during the test. Hence only the higher curb 
weight caused by heavier truck components would play a role in 
affecting measured test results. However towing capacity can be a 
significant factor to consider because HD pickup truck towing 
capacities can be quite large, with a correspondingly large effect on 
design.
    We note too that, from a purchaser perspective, payload and towing 
capability typically play a greater role than physical dimensions in 
influencing purchaser decisions on which heavy-duty vehicle to buy. For 
passenger vans, seating capacity is of course a major consideration, 
but this correlates closely with payload weight.
    Although heavy-duty vehicles are traditionally classified by their 
GVWR, we do not believe that GVWR is the best weight-based attribute on 
which to base GHG and fuel consumption standards for this group of 
vehicles. GVWR is a function of not only payload capacity but of 
vehicle curb weight as well; in fact, it is the simple sum of the two. 
Allowing more GHG emissions from vehicles with higher curb weight tends 
to penalize lightweighted vehicles with comparable payload capabilities 
by making them meet more stringent standards than they would have had 
to meet without the weight reduction. The same would be true for 
another common weight-based measure, the gross vehicle combination 
weight, which adds the maximum combined towing and payload weight to 
the curb weight.
    Similar concerns about using weight-based attributes that include 
vehicle curb weight were raised in the EPA/NHTSA proposal for light-
duty GHG and fuel economy standards: ``footprint-based standards 
provide an incentive to use advanced lightweight materials and 
structures that would be discouraged by weight-based standards'', and 
``there is less risk of `gaming' (artificial manipulation of the 
attribute(s) to achieve a more favorable target) by increasing 
footprint under footprint-based standards than by increasing vehicle 
mass under weight-based standards--it is relatively easy for a 
manufacturer to add enough weight to a vehicle to decrease its 
applicable fuel economy target a significant amount, as compared to 
increasing vehicle footprint'' (74 FR 49685, September 28,

[[Page 57162]]

2009). The agencies believe that using payload and towing capacities as 
the work-based attributes avoids the above-mentioned disincentive for 
the use of lightweighting technology by taking vehicle curb weight out 
of the standards determination.
    After taking these considerations into account, EPA and NHTSA 
proposed to set standards for HD pickups and vans based on the proposed 
``work factor'' attribute that combines vehicle payload capacity and 
vehicle towing capacity, in pounds, with an additional fixed adjustment 
for four-wheel drive (4wd) vehicles. This adjustment accounts for the 
fact that 4wd, critical to enabling the many off-road heavy-duty work 
applications, adds roughly 500 lb to the vehicle weight. There was 
consensus in the public comments supporting this attribute, and the 
agencies are adopting it as proposed. Target GHG and fuel consumption 
standards will be determined for each vehicle with a unique work factor 
(analogous to a target for each discrete vehicle footprint in the 
light-duty vehicle rules). These targets will then be production 
weighted and summed to derive a manufacturer's annual fleet average 
standard for its heavy-duty pickups and vans. Widespread support for 
the proposed work factor-based approach to standards and fleet average 
approach to compliance was expressed in the comments we received.
    To ensure consistency and help preclude gaming, we are finalizing 
the proposed provision that payload capacity be defined as GVWR minus 
curb weight, and towing capacity as GCWR minus GVWR. For purposes of 
determining the work factor, GCWR is defined according to the Society 
of Automotive Engineers (SAE) Recommended Practice J2807 APR2008, GVWR 
is defined consistent with EPA's criteria pollutants program, and curb 
weight is defined as in 40 CFR 86.1803-01. Based on analysis of how 
CO2 emissions and fuel consumption correlate to work factor, 
we believe that a straight line correlation is appropriate across the 
spectrum of possible HD pickups and vans, and that vehicle distinctions 
such as Class 2b versus Class 3 need not be made in setting standards 
levels for these vehicles.\113\ This approach was supported by 
commenters.
---------------------------------------------------------------------------

    \113\ Memorandum from Anthony Neam and Jeff Cherry, U.S.EPA, to 
docket EPA-HQ-OAR-2010-0162, October 18, 2010.
---------------------------------------------------------------------------

    We note that payload/towing-dependent gram per mile and gallon per 
100 mile standards for HD pickups and vans parallel the gram per ton-
mile and gallon per 1,000 ton-mile standards being finalized for Class 
7 and 8 combination tractors and for vocational vehicles. Both 
approaches account for the fact that more work is done, more fuel is 
burned, and more CO2 is emitted in moving heavier loads than 
in moving lighter loads. Both of these load-based approaches avoid 
penalizing vehicle designers wishing to reduce GHG emissions and fuel 
consumption by reducing the weight of their trucks. However, the 
sizeable diversity in HD work truck and van applications, which go well 
beyond simply transporting freight, and the fact that the curb weights 
of these vehicles are on the order of their payload capacities, suggest 
that setting simple gram/ton-mile and gallon/ton-mile standards for 
them is not appropriate. Even so, we believe that our setting of 
payload-based standards for HD pickups and vans is consistent with the 
NAS Report's recommendation in favor of load-specific fuel consumption 
standards. Again, commenters agreed with this approach to setting HD 
pickup and van standards.
    These attribute-based CO2 and fuel consumption standards 
are meant to be relatively consistent from a stringency perspective. 
Vehicles across the entire range of the HD pickup and van segment have 
their respective target values for CO2 emissions and fuel 
consumption, and therefore all HD pickups and vans will be affected by 
the standard. With this attribute-based standards approach, EPA and 
NHTSA believe there should be no significant effect on the relative 
distribution of vehicles with differing capabilities in the fleet, 
which means that buyers should still be able to purchase the vehicle 
that meets their needs.
(c) Standards
    The agencies are finalizing standards based on a technology 
analysis performed by EPA to determine the appropriate HD pickup and 
van standards. This analysis, described in detail in RIA Chapter 2, 
considered:
     The level of technology that is incorporated in current 
new HD pickups and vans,
     The available data on corresponding CO2 
emissions and fuel consumption for these vehicles,
     Technologies that would reduce CO2 emissions 
and fuel consumption and that are judged to be feasible and appropriate 
for these vehicles through the 2018 model year,
     The effectiveness and cost of these technologies for HD 
pickup and vans,
     Projections of future U.S. sales for HD pickup and vans, 
and
     Forecasts of manufacturers' product redesign schedules.
    Based on this analysis, EPA is finalizing the proposed 
CO2 attribute-based target standards shown in Figure 0-2 and 
II-3, and NHTSA is finalizing the equivalent attribute-based fuel 
consumption target standards, also shown in Figure 0-2 and II-3, 
applicable in model year 2018. These figures also shows phase-in 
standards for model years before 2018, and their derivation is 
explained below, along with alternative implementation schedules to 
ensure equivalency between the EPA and NHTSA programs while meeting 
respective statutory obligations. Also, for reasons discussed below, 
the agencies proposed and are establishing separate targets for 
gasoline-fueled (and any other Otto-cycle) vehicles and diesel-fueled 
(and any other Diesel-cycle) vehicles. The targets will be used to 
determine the production-weighted fleet average standards that apply to 
the combined diesel and gasoline fleet of HD pickups and vans produced 
by a manufacturer in each model year.

[[Page 57163]]

[GRAPHIC] [TIFF OMITTED] TR15SE11.002

    \114\ The NHTSA program provides voluntary standards for model 
years 2014 and 2015. Target line functions for 2016-2018 are for the 
second NHTSA alternative described in Section II.C(d)(ii).

---------------------------------------------------------------------------

[[Page 57164]]

[GRAPHIC] [TIFF OMITTED] TR15SE11.003

    Described mathematically, EPA's and NHTSA's target standards are 
defined by the following formulae:
---------------------------------------------------------------------------

    \115\ The NHTSA program provides voluntary standards for model 
years 2014 and 2015. Target line functions for 2016-2018 are for the 
second NHTSA alternative described in Section II.C(d)(ii).

EPA CO2 Target (g/mile) = [a x WF] + b
NHTSA Fuel Consumption Target (gallons/100 miles) = [c x WF] + d

Where:

WF = Work Factor = [0.75 x (Payload Capacity + xwd)] + [0.25 x 
Towing Capacity]
Payload Capacity = GVWR (lb) - Curb Weight (lb)
xwd = 500 lb if the vehicle is equipped with 4wd, otherwise equals 0 
lb
Towing Capacity = GCWR (lb) - GVWR (lb)
Coefficients a, b, c, and d are taken from Table II-12 or Table II-
13.
---------------------------------------------------------------------------

    \116\ The NHTSA program provides voluntary standards for model 
years 2014 and 2015. Target line functions for 2016-2018 are for the 
second NHTSA alternative described in Section II.C(d)(ii).

 Table II-12--Coefficients for HD Pickup and Van Target Standards \116\
------------------------------------------------------------------------
           Model year                a        b          c          d
------------------------------------------------------------------------
                             Diesel Vehicles
------------------------------------------------------------------------
2014............................   0.0478      368     0.000470     3.61
2015............................   0.0474      366     0.000466     3.60
2016............................   0.0460      354     0.000452     3.48
2017............................   0.0445      343     0.000437     3.37
2018 and later..................   0.0416      320     0.000409     3.14
------------------------------------------------------------------------
                            Gasoline Vehicles
------------------------------------------------------------------------
2014............................   0.0482      371     0.000542     4.17
2015............................   0.0479      369     0.000539     4.15
2016............................   0.0469      362     0.000528     4.07
2017............................   0.0460      354     0.000518     3.98
2018 and later..................   0.0440      339     0.000495     3.81
------------------------------------------------------------------------


[[Page 57165]]


    Table II-13--Coefficients for NHTSA's First Alternative and EPA's
             Alternative HD Pickup and Van Target Standards
------------------------------------------------------------------------
           Model year                a        b          c          d
------------------------------------------------------------------------
                             Diesel Vehicles
------------------------------------------------------------------------
2014 a..........................   0.0478      368     0.000470     3.61
2015 a..........................   0.0474      366     0.000466     3.60
2016-2018.......................   0.0440      339     0.000432     3.33
2019 and later..................   0.0416      320     0.000409     3.14
------------------------------------------------------------------------
                            Gasoline Vehicles
------------------------------------------------------------------------
2014 a..........................   0.0482      371     0.000542     4.17
2015 a..........................   0.0479      369     0.000539     4.15
2016-2018.......................   0.0456      352     0.000513     3.96
2019 and later..................   0.0440      339     0.000495     3.81
------------------------------------------------------------------------
Notes:
a NHTSA standards will be voluntary in 2014 and 2015.

    These targets are based on a set of vehicle, engine, and 
transmission technologies assessed by the agencies and determined to be 
feasible and appropriate for HD pickups and vans in the 2014-2018 
timeframe. See Section III.B for a detailed analysis of these vehicle, 
engine and transmission technologies, including their feasibility, 
costs, and effectiveness in HD pickups and vans.
    To calculate a manufacturer's HD pickup and van fleet average 
standard, the agencies are requiring that separate target curves be 
used for gasoline and diesel vehicles. The agencies estimate that in 
2018 the target curves will achieve 15 and 10 percent reductions in 
CO2 and fuel consumption for diesel and gasoline vehicles, 
respectively, relative to a common baseline for current (model year 
2010) HD pickup trucks and vans. An additional two percent reduction in 
GHGs will be achieved by the direct air conditioning leakage standard 
in the EPA standards. These reductions are based on the agencies' 
assessment of the feasibility of incorporating technologies (which 
differ significantly for gasoline and diesel powertrains) in the 2014-
2018 model years, and on the differences in relative efficiency in the 
current gasoline and diesel vehicles. The resulting reductions 
represent roughly equivalent stringency levels for gasoline and diesel 
vehicles, which is important in ensuring our program maintains product 
choices available to vehicle buyers.
    In written comments on the proposal, Cummins objected to setting 
separate diesel and gasoline vehicle standards, on the basis that it 
increases the burden for diesel engine manufacturers more than for 
gasoline engine manufacturers, and thereby could shift market share 
away from diesels. EMA argued for fuel-neutrality based on historical 
precedent and the fact that GHGs emitted by one type of engine are no 
different than those emitted by another type of engine. We believe that 
both engine types have roughly equivalent redesign burdens as evidenced 
by the feasibility and cost analysis in RIA Chapter 2. Also, even 
though the emissions and fuel consumption reductions are expressed from 
a common diesel/gasoline baseline in these final rules, the actual 
starting base for diesels is at a lower level than for gasoline 
vehicles. Other industry commenters, including those with sizeable 
diesel sales, expressed general support for the standards. The agencies 
agree that standards that do not distinguish between fuel types are 
generally preferable where technological or market-based reasons do not 
strongly argue otherwise. These technological differences exist 
presently between gasoline and diesel engines for GHGs, as described 
above. The agencies emphasize, however, that they are not committed to 
perpetuating separate GHG standards for gasoline and diesel heavy-duty 
vehicles and engines, and expect to reexamine the need for separate 
gasoline/diesel standards in the next rulemaking.
    Environmental groups and others commented that the proposed 
standards were not stringent enough, citing the heavy-duty vehicle NAS 
study finding that technologies such as hybridization are feasible. 
However, in the ambitious timeframe we are focusing on for these rules, 
targeting as it does technologies implementable in the HD pickup and 
van fleet starting in 2014 and phasing in with normal product redesign 
cycles through 2018, our assessment shows that the standards we are 
establishing are appropriate. More advanced technologies considered in 
the NAS report would be appropriate for consideration in future 
rulemaking activity. Additional conventional technologies identified by 
commenters as promising in light-duty applications and potentially 
useful for HD applications are discussed in RIA chapter 2.
    The NHTSA fuel consumption target curves and the EPA GHG target 
curves are equivalent. The agencies established the target curves using 
the direct relationship between fuel consumption and CO2 
using conversion factors of 8,887 g CO2/gallon for gasoline 
and 10,180 g CO2/gallon for diesel fuel.
    It is expected that measured performance values for CO2 
will generally be equivalent to fuel consumption. However, as explained 
below in Section 0, EPA is finalizing a provision for manufacturers to 
use CO2 credits to help demonstrate compliance with 
N2O and CH4 emissions standards, by expressing 
any N2O and CH4 undercompliance in terms of their 
CO2-equivalent and applying the needed CO2 
credits. For test families that do not use this compliance alternative, 
the measured performance values for CO2 and fuel consumption 
will be equivalent because the same test runs and measurement data will 
be used to determine both values, and calculated fuel consumption will 
be based on the same conversion factors that are used to establish the 
relationship between the CO2 and fuel consumption target 
curves (8,887 g CO2/gallon for gasoline and 10,180 g 
CO2/gallon for diesel fuel). For manufacturers that choose 
to use the EPA provision for CO2 credit use in demonstrating 
N2O and CH4 compliance, compliance with the 
CO2 standard will not be directly equivalent to compliance 
with the NHTSA fuel consumption standard.

[[Page 57166]]

(d) Implementation Plan
(i) EPA Program Phase-In MY 2014-2018
    EPA is finalizing the proposed provision that the GHG standards be 
phased in gradually over the 2014-2018 model years, with full 
implementation effective in the 2018 model year. Therefore, 100 percent 
of a manufacturer's vehicle fleet will need to meet a fleet-average 
standard that will become increasingly more stringent each year of the 
phase-in period. For both gasoline and diesel vehicles, this phase-in 
will be 15-20-40-60-100 percent of the model year 2018 stringency in 
model years 2014-2015-2016-2017-2018, respectively. These percentages 
reflect stringency increases from a baseline performance level for 
model year 2010, determined by the agencies based on EPA and 
manufacturer data. Because these vehicles are not currently regulated 
for GHG emissions, this phase-in takes the form of target line 
functions for gasoline and diesel vehicles that become increasingly 
stringent over the phase-in model years. These year-by-year functions 
have been derived in the same way as the 2018 function, by taking a 
percent reduction in CO2 from a common unregulated baseline. 
For example, in 2014 the reduction for both diesel and gasoline 
vehicles will be 15 percent of the fully-phased-in reductions. Figures 
II-2 and II-3, and Table 0-12, reflect this phase-in approach.
    EPA is also providing manufacturers with an optional alternative 
implementation schedule in model years 2016 through 2018, equivalent to 
NHTSA's first alternative for standards that do not change over these 
model years, described below. Under this option the phase-in will be 
15-20-67-67-67-100 percent of the model year 2019 stringency in model 
years 2014-2015-2016-2017-2018-2019, respectively. Table 0-13, above, 
provides the coefficients ``a'' and ``b'' for this manufacturer's 
alternative. As explained below, this alternative will provide roughly 
equivalent overall CO2 reductions and fuel consumption 
improvements as the 15-20-40-60-100 percent phase-in. In addition, as 
explained below, the stringency of this alternative was established by 
NHTSA such that a manufacturer with a stable production volume and mix 
over the model year 2016-2018 period could use Averaging, Banking and 
Trading to comply with either alternative and have a similar credit 
balance at the end of model year 2018.
    Under the above-described alternatives, each manufacturer will need 
to demonstrate compliance with the applicable fleet average standard 
using that year's target function over all of its HD pickups and vans 
starting with its MY 2014 fleet of HD pickups and vans. No comments 
were received in support of an alternative approach that EPA requested 
comment on, involving phasing in an annually increasing percentage of 
each manufacturer's sales volume.
(ii) NHTSA Program Phase-In 2016 and Later
    NHTSA is finalizing the proposed provision to allow manufacturers 
to select one of two fuel consumption standard alternatives for model 
years 2016 and later. Each manufacturer will select an alternative in 
its joint pre-model year report, discussed below, that is now required 
to be electronically submitted to the agencies; and, once selected, the 
alternative will apply for model years 2016 and later, and cannot be 
reversed. The first alternative will define a fuel consumption target 
line function for gasoline vehicles and a target line function for 
diesel vehicles that will not change for model years 2016 to 2018. The 
target line function coefficients are provided in Table II-13.
    The second alternative will be equivalent to the EPA target line 
functions in each model year starting in 2016 and continuing 
afterwards. Stringency of fuel consumption standards will increase 
gradually for the 2016 and later model years. Relative to a model year 
2010 unregulated baseline for both gasoline and diesel vehicles, 
stringency will be 40, 60, and 100 percent of the 2018 target line 
function in model years 2016, 2017, and 2018, respectively. The 
stringency of the target line functions in the first alternative for 
model years 2016-2017-2018-2019 is 67-67-67-100 percent, respectively, 
of the 2019 stringency in the second alternative. The stringency of the 
first alternative was established so that a manufacturer with a stable 
production volume and mix over the model year 2016-2018 period could 
use Averaging, Banking and Trading to comply with either alternative 
and have a similar credit balance at the end of model year 2018 under 
the EPA and NHTSA programs.
(iii) NHTSA Voluntary Standards Period
    NHTSA is finalizing the proposed provision that manufacturers may 
voluntarily opt into the NHTSA HD pickup and van program in model years 
2014 or 2015. If a manufacturer elects to opt in to the program, it 
must stay in the program for all the optional model years. 
Manufacturers that opt in become subject to NHTSA standards for all 
regulatory categories. To opt into the program, a manufacturer must 
declare its intent to opt in to the program in its Pre-Model Year 
Report. The agencies have finalized new requirements for manufacturers 
to provide all early model declarations as a part of the pre-model year 
reports. See regulatory text for 49 CFR 535.8 for information related 
to the Pre-Model Year Report. A manufacturer would begin tracking 
credits and debits beginning in the model year in which they opt into 
the program. The handling of credits and debits would be the same as 
for the mandatory program.
    For manufacturers that opt into NHTSA's HD pickup and van fuel 
consumption program in 2014 or 2015, the stringency would increase 
gradually each model year. Relative to a model year 2010 unregulated 
baseline, for both gasoline and diesel vehicles, stringency would be 
15-20 percent of the model year 2019 target line function stringency 
(under the NHTSA first alternative) and 15-20 percent of the model year 
2018 target line function stringency (under the NHTSA second 
alternative) in model years 2014-2015, respectively. The corresponding 
absolute standards target levels are provided in Figure II-2 and II-3, 
and the accompanying equations.
(2) What are the HD pickup and van test cycles and procedures?
    EPA and NHTSA are finalizing the proposed provision that HD pickup 
and van testing be conducted using the same heavy-duty chassis test 
procedures currently used by EPA for measuring criteria pollutant 
emissions from these vehicles, but with the addition of the highway 
fuel economy test cycle (HFET) currently required only for light-duty 
vehicle GHG emissions and fuel economy testing. Although the highway 
cycle driving pattern is identical to that of the light-duty test, 
other test parameters for running the HFET, such as test vehicle loaded 
weight, are identical to those used in running the current EPA Federal 
Test Procedure for complete heavy-duty vehicles.
    The GHG and fuel consumption results from vehicle testing on the 
Light-duty FTP and the HFET will be weighted by 55 percent and 45 
percent, respectively, and then averaged in calculating a combined 
cycle result. This result corresponds with the data used to develop the 
work factor-based CO2 and fuel consumption standards, since 
the data on the baseline and technology efficiency was also

[[Page 57167]]

developed in the context of these test procedures. The addition of the 
HFET and the 55/45 cycle weightings are the same as for the light-duty 
CO2 and CAFE programs, as we believe the real world driving 
patterns for HD pickups and vans are not too unlike those of light-duty 
trucks, and we are not aware of data specifically on these patterns 
that would lead to a different choice of cycles and weightings, nor did 
any commenters provide such data. More importantly, we believe that the 
55/45 weightings will provide for effective reductions of GHG emissions 
and fuel consumption from these vehicles, and that other weightings, 
even if they were to more precisely match real world patterns, are not 
likely to significantly improve the program results.
    Another important parameter in ensuring a robust test program is 
vehicle test weight. Current EPA testing for HD pickup and van criteria 
pollutants is conducted with the vehicle loaded to its Adjusted Loaded 
Vehicle Weight (ALVW), that is, its curb weight plus [frac12] of the 
payload capacity. This is substantially more challenging than loading 
to the light-duty vehicle test condition of curb weight plus 300 
pounds, but we believe that this loading for HD pickups and vans to 
[frac12] payload better fits their usage in the real world and will 
help ensure that technologies meeting the standards do in fact provide 
real world reductions. The choice is likewise consistent with use of an 
attribute based in considerable part on payload for the standard. We 
see no reason to set test load conditions differently for GHGs and fuel 
consumption than for criteria pollutants, and we are not aware of any 
new information (such as real world load patterns) since the ALVW was 
originally set this way that would support a change in test loading 
conditions, nor did any commenters provide such information. We are 
therefore using ALVW for test vehicle loading in GHG and fuel 
consumption testing.
    Additional provisions for our final testing and compliance program 
are provided in Section V.B.
(3) How are the HD pickup and van standards structured?
    EPA and NHTSA are finalizing the proposed fleet average standards 
for new HD pickups and vans, based on a manufacturer's new vehicle 
fleet makeup. In addition, EPA is finalizing proposed in-use standards 
that apply to the individual vehicles in this fleet over their useful 
lives. The compliance provisions for these fleet average and in-use 
standards for HD pickups and vans are largely based on the recently 
promulgated light-duty GHG and fuel economy program, as described in 
detail in the proposal.
(a) Fleet Average Standards
    In the programs we are finalizing, each manufacturer will have a 
GHG standard and a fuel consumption standard unique to its new HD 
pickup and van fleet in each model year, depending on the load 
capacities of the vehicle models produced by that manufacturer, and on 
the U.S.-directed production volume of each of those models in that 
model year. Vehicle models with larger payload/towing capacities have 
individual targets at numerically higher CO2 and fuel 
consumption levels than lower payload/towing vehicles, as discussed in 
Section II.C(1). The fleet average standard for a manufacturer is a 
production-weighted average of the work factor-based targets assigned 
to unique vehicle configurations within each model type produced by the 
manufacturer in a model year.
    The fleet average standard with which the manufacturer must comply 
is based on its final production figures for the model year, and thus a 
final assessment of compliance will occur after production for the 
model year ends. Because compliance with the fleet average standards 
depends on actual test group production volumes, it is not possible to 
determine compliance at the time the manufacturer applies for and 
receives an EPA certificate of conformity for a test group. Instead, at 
certification the manufacturer will demonstrate a level of performance 
for vehicles in the test group, and make a good faith demonstration 
that its fleet, regrouped by unique vehicle configurations within each 
model type, is expected to comply with its fleet average standard when 
the model year is over. EPA will issue a certificate for the vehicles 
covered by the test group based on this demonstration, and will include 
a condition in the certificate that if the manufacturer does not comply 
with the fleet average, then production vehicles from that test group 
will be treated as not covered by the certificate to the extent needed 
to bring the manufacturer's fleet average into compliance. As in the 
light-duty program, additional ``model type'' testing will be conducted 
by the manufacturer over the course of the model year to supplement the 
initial test group data. The emissions and fuel consumption levels of 
the test vehicles will be used to calculate the production-weighted 
fleet averages for the manufacturer, after application of the 
appropriate deterioration factor to each result to obtain a full useful 
life value. See generally 75 FR 25470-25472.
    EPA and NHTSA do not currently anticipate notable deterioration of 
CO2 emissions and fuel consumption performance, and are 
therefore requiring that an assigned deterioration factor be applied at 
the time of certification: an additive assigned deterioration factor of 
zero, or a multiplicative factor of one will be used. EPA and NHTSA 
anticipate that the deterioration factor may be updated from time to 
time, as new data regarding emissions deterioration for CO2 
are obtained and analyzed. Additionally, EPA and NHTSA may consider 
technology-specific deterioration factors, should data indicate that 
certain control technologies deteriorate differently than others. See 
also 75 FR 25474.
(b) In-Use Standards
    Section 202(a)(1) of the CAA specifies that EPA set emissions 
standards that are applicable for the useful life of the vehicle. The 
in-use standards that EPA is finalizing apply to individual vehicles. 
NHTSA is not adopting in-use standards because they are not required 
under EISA, and because it is not currently anticipated that there will 
be any notable deterioration of fuel consumption. For the EPA program, 
compliance with the in-use standard for individual vehicles and vehicle 
models will not impact compliance with the fleet average standard, 
which will be based on the production-weighted average of the new 
vehicles.
    EPA is finalizing the proposed provision that the in-use standards 
for HD pickups and vans be established by adding an adjustment factor 
to the full useful life emissions and fuel consumption results used to 
calculate the fleet average. EPA is also finalizing the proposed 
provision that the useful life for these vehicles with respect to GHG 
emissions be set equal to their useful life for criteria pollutants: 11 
years or 120,000 miles, whichever occurs first (40 CFR 86.1805-04(a)).
    As discussed above, we are finalizing the proposed provision that 
certification test results obtained before and during the model year be 
used directly to calculate the fleet average emissions for assessing 
compliance with the fleet average standard. Therefore, this assessment 
and the fleet average standard itself do not take into account test-to-
test variability and production variability that can affect measured 
in-use levels. For this reason, EPA is finalizing the proposed 
adjustment factor for the in-use standard to provide some margin for 
production and test-to-

[[Page 57168]]

test variability that could result in differences between the initial 
emission test results used to calculate the fleet average and emission 
results obtained during subsequent in-use testing. EPA is finalizing 
the proposed provision that each model's in-use CO2 standard 
be the model-specific level used in calculating the fleet average, plus 
10 percent. This is the same as the approach taken for light-duty 
vehicle GHG in-use standards (See 75 FR 25473-25474). No adverse 
comments were received on this proposed provision.
    As it does now for heavy-duty vehicle criteria pollutants, EPA will 
use a variety of mechanisms to conduct assessments of compliance with 
the in-use standards, including pre-production certification and in-use 
monitoring once vehicles enter customer service. The full useful life 
in-use standards apply to vehicles that have entered customer service. 
The same standards apply to vehicles used in pre-production and 
production line testing, except that deterioration factors are not 
applied.
(4) What HD pickup and van flexibility provisions are being 
established?
    This program contains substantial flexibility in how manufacturers 
can choose to implement the EPA and NHTSA standards while preserving 
their timely benefits for the environment and energy security. Primary 
among these flexibilities are the gradual phase-in schedule, 
alternative compliance paths, and corporate fleet average approach 
which encompasses averaging, banking and trading described above. 
Additional flexibility provisions are described briefly here and in 
more detail in Section IV.
    As explained in Section II.C(3), we are finalizing the proposed 
provision that, at the end of each model year, when production for the 
model year is complete, a manufacturer calculate its production-
weighted fleet average CO2 and fuel consumption. Under this 
approach, a manufacturer's HD pickup and van fleet that achieves a 
fleet average CO2 or fuel consumption level better than its 
standard will be allowed to generate credits. Conversely, if the fleet 
average CO2 or fuel consumption level does not meet its 
standard, the fleet would incur debits (also referred to as a 
shortfall).
    A manufacturer whose fleet generates credits in a given model year 
will have several options for using those credits to offset emissions 
from other HD pickups and vans. These options include credit carry-
back, credit carry-forward, and credit trading. These provisions exist 
in the light-duty 2012-2016 MY vehicle rule, and similar provisions are 
part of EPA's Tier 2 program for light-duty vehicle criteria pollutant 
emissions, as well as many other mobile source standards issued by EPA 
under the CAA. The manufacturer will be able to carry back credits to 
offset a deficit that had accrued in a prior model year and was 
subsequently carried over to the current model year, with a limitation 
on the carry-back of credits to three model years, consistent with the 
light-duty program. We are finalizing the proposed provision that, 
after satisfying any need to offset pre-existing deficits, a 
manufacturer may bank remaining credits for use in future years, with a 
limitation on the carry-forward of credits to five model years. We are 
also finalizing the proposed provision that manufacturers may certify 
their HD pickup and van fleet a year early, in MY 2013, to generate 
credits against the MY 2014 standards. This averaging, banking, and 
trading program for HD pickups and vans is discussed in more detail in 
Section IV.A. For reasons discussed in detail in that section, we are 
not finalizing any credit transferability to or from other credit 
programs or averaging sets.
    Consistent with the President's May 21, 2010, directive to promote 
advanced technology vehicles and with the agencies' respective 
statutory authorities, we are adopting flexibility provisions that 
parallel similar provisions adopted in the light-duty program. These 
include credits for advance technology vehicles such as electric 
vehicles, and credits for innovative technologies that are shown by the 
manufacturer to provide GHG and fuel consumption reductions in real 
world driving, but not on the test cycle. See Section IV.B.

D. Class 2b-8 Vocational Vehicles

    Heavy-duty vehicles serve a vast range of functions including 
service for urban delivery, refuse hauling, utility service, dump, 
concrete mixing, transit service, shuttle service, school bus, 
emergency, motor homes,\117\ and tow trucks to name only a small subset 
of the full range of vehicles. The vehicles designed to serve these 
functions are as unique as the jobs they do. They are vastly 
different--one from the other--in size, shape and function. The 
agencies were unable to develop a specific vehicle definition based on 
the characteristics of these vehicles. Instead at proposal, we proposed 
to define that Class 2b-8 vocational vehicles as all heavy-duty 
vehicles which are not included in the Heavy-duty Pickup Truck and Van 
or the Class 7 and 8 Tractor categories. In effect, we said everything 
that is not a combination tractor or a pickup truck or van is a 
vocational vehicle. We are finalizing that definition as proposed 
reflecting the same challenges we faced at proposal regarding defining 
the full range of heavy-duty vehicles. As at proposal, recreational 
vehicles are included under EPA's standards but are not included under 
NHTSA's final standards. The agencies note that we are adding 
vocational tractors to the vocational vehicle category in the final 
rulemaking, as described above in Section II.B.
---------------------------------------------------------------------------

    \117\ See above for discussion of applicability of NHTSA's 
standards to non-commercial vehicles.
---------------------------------------------------------------------------

    The agencies proposed that Class 4 pickup trucks although similar 
to Class 2b and 3 vehicles be included in the vocational vehicle 
category. Comments from EMA, Cummins, NTEA and Navistar supported the 
premise that Class 4 vehicles belong as part of the vocational vehicle 
program because they are specifically designed and engineered to meet 
vocational requirements. They stated that components such as 
transmissions, axles, frames, and tires differ from the similar pickup 
trucks and vans in the Class 2b and 3 market. We agree with commenters' 
arguments that there are a number of important differences between the 
Class 4 and Class 3 trucks it unreasonable to regulate Class 4 vehicles 
under the standards for heavy duty pickups and vans. As a result, we 
are keeping Class 4 vehicles in the vocational vehicle category, but 
are allowing the optional chassis certification of Class 4 and 5 
vehicles. (See Section V.B(1)(e)).
    As mentioned in Section I, vocational vehicles undergo a complex 
build process. Often an incomplete chassis is built by a chassis 
manufacturer with an engine purchased from an engine manufacturer and a 
transmission purchased from another manufacturer. A body manufacturer 
purchases an incomplete chassis which is then completed by attaching 
the appropriate features to the chassis.
    The diversity in the vocational vehicle segment can be primarily 
attributed to the variety of vehicle bodies rather than to the chassis. 
For example, a body builder can build either a Class 6 bucket truck or 
a Class 6 delivery truck from the same Class 6 chassis. The aerodynamic 
difference between these two vehicles due to their bodies will lead to 
different baseline fuel consumption and GHG emissions. However, the 
baseline fuel consumption and emissions due to the components included 
in the common chassis (such as the engine, drivetrain, frame, and

[[Page 57169]]

tires) will be the same between these two types of complete vehicles.
    The agencies face difficulties in establishing the baseline 
CO2 and fuel consumption performance for the wide variety of 
complete vocational vehicles because of the very large number of 
vehicle types and the need to conduct testing on each of the vehicle 
types to establish the baseline. To establish standards for a complete 
vocational vehicle, it would be necessary to assess the potential for 
fuel consumption and GHG emissions improvement for each of these 
vehicle types and to establish standards for each vehicle type. Because 
of the size and complexity of this task, the agencies judged it was not 
practical to regulate complete vocational vehicles for this first fuel 
consumption and GHG emissions program. To overcome the lack of baseline 
information from the different vehicle types and to still achieve 
improvements to fuel consumption and GHG emissions, the agencies 
proposed to set standards for the chassis manufacturers of vocational 
vehicles (but not the body builders) and the engine manufacturers. 
Chassis manufacturers represent a limited number of companies as 
compared to body builders, which are made up of a diverse set of 
companies that are typically small businesses. These companies would 
need to be regulated if whole vehicle standards were established.
    Similar to combination tractors, the agencies proposed to set 
separate vehicle and engine standards for vocational vehicles. A number 
of comments were received on the proposal to regulate chassis and 
engine manufacturers. The agencies received comments from DTNA 
supporting the proposal to regulate the chassis manufacturer but not 
body manufacturers. While organizations like Cummins and ICCT expressed 
support for separate engine and vehicle standards, Navistar, Pew, and 
Volvo, in contrast, opposed separate engine and chassis standards, 
stating that separate engine standards disadvantages integrated truck/
engine manufacturers and full vehicle standards should be required. 
Volvo asked that the standards include an alternative integrated 
standard as well as complete vehicle modeling and testing beginning in 
2017. ACEEE and Sierra Club stated that the proposed standards and test 
procedures should move the agencies closer to full vehicle testing.
    Although the agencies understand that full vehicle standards would 
allow integrated truck/engine manufacturers--such as electrified 
accessories and weight reduction--the agencies are finalizing separate 
standards for vocational vehicles that apply to chassis manufacturers 
and engine standards for engines installed in these vehicles that apply 
to engine manufacturers. The agencies continue to believe that it is 
not practical to regulate complete vocational vehicles for this first 
fuel consumption and GHG emissions program because of the size and 
complexity of the task associated with assessing the potential for fuel 
consumption and GHG emissions improvement for each of the myriad types 
of vocational vehicles. This issue is discussed further in comment 
responses found in sections 5 and 6.1.4 of the Response to Comment 
Document, as well as in the following section of the preamble. Thus, 
the agencies are finalizing a set of standards for the chassis 
manufacturers of vocational vehicles (but not the body builders) and 
for the manufacturers of HD engines used in vocational vehicles.
(1) What are the vocational vehicle and engine CO2 and fuel 
consumption standards and their timing?
    In the NPRM, the agencies proposed vehicle standards based on the 
agencies' assessment of the availability of low rolling resistance 
tires that could be applied generally to vocational vehicles across the 
entire category. The agencies considered the possibility of including 
other technologies in determining the proposed stringency of the 
vocational vehicle standards, such as aerodynamic improvements, but as 
discussed in the NPRM, tentatively concluded that such improvements 
would not be appropriate for basing vehicle standard stringency in this 
phase of the rulemaking.\118\ For example, the aerodynamics of a 
recovery vehicle are impacted significantly by the equipment such as 
the arm located on the exterior of the truck.\119\ The agencies found 
little opportunity to improve the aerodynamics of the equipment on the 
truck. The agencies also evaluated the aerodynamic opportunities 
discussed in the NAS report. The panel found that there was minimal 
fuel consumption reduction opportunity through aerodynamic technologies 
for bucket trucks, transit buses, and refuse trucks \120\ primarily due 
to the low vehicle speed in normal operation. The panel did report that 
there are opportunities to reduce the fuel consumption of straight 
trucks by approximately 1 percent for trucks which operate at the 
average speed typical of a pickup and delivery truck (30 mph), although 
the opportunity is greater for vehicles that operate at higher 
speeds.\121\
---------------------------------------------------------------------------

    \118\ See 75 FR at 74241.
    \119\ A recovery vehicle removes or recovers vehicles that are 
disabled (broken down).
    \120\ See 2010 NAS Report, Note 21, page 133.
    \121\ See 2010 NAS Report, Note 21, page 110.
---------------------------------------------------------------------------

    The agencies received comments from the Motor Equipment 
Manufacturers Association, Eaton, NRDC, NESCAUM, NACAA, ACEEE, ICCT, 
Navistar, Arvin Meritor, the Union of Concerned Scientists and others 
that technologies such as idle reduction, advanced transmissions, 
advanced drivetrains, weight reduction, hybrid powertrains, and 
improved auxiliaries provide opportunities to reduce fuel consumption 
from vocational vehicles. Commenters asked that the agencies establish 
regulations that would reflect performance of these technologies and 
essentially force their utilization.
    The agencies assessed these technologies and have concluded that 
they may have the potential to reduce fuel consumption and GHG 
emissions from at least certain vocational vehicles, but the agencies 
have not been able to estimate baseline fuel consumption and GHG 
emissions levels for each type of vocational vehicle and for each type 
of technology, given the wide variety of models and uses of vocational 
vehicles. For example, idle reduction technologies such as APUs and 
cabin heaters can reduce workday idling associated with vocational 
vehicles. However, characterizing idling activity for the vocational 
segment in order to quantify the benefits of idle reduction technology 
is complicated by the variety of duty cycles found in the sector. 
Idling in school buses, fire trucks, pickup trucks, delivery trucks, 
and other types of vocational vehicles varies significantly. Given the 
great variety of duty cycles and operating conditions of vocational 
vehicles and the timing of these rules, it is not feasible at this time 
to establish an accurate baseline for quantifying the expected 
improvements which could result from use of idle reduction 
technologies. Similarly, for advanced drivetrains and advanced 
transmissions determining a baseline configuration, or a set of 
baseline configurations, is extremely difficult given the variety of 
trucks in this segment. The agencies do not believe that we can 
legitimately base standard stringency on the use of technologies for 
which we cannot identify baseline configurations, because absent 
baseline emissions and baseline fuel consumption, the emissions 
reductions achieved from introduction of the technology cannot be 
quantified. For some technologies, such as weight

[[Page 57170]]

reduction and improved auxiliaries--such as electrically driven power 
steering pumps and the vehicle's air conditioning system--the need to 
limit technologies to those under the control of the chassis 
manufacturer further restricted the agencies' options for predicating 
standard stringency on use of these technologies. For example, 
lightweight components that are under the control of chassis 
manufacturers are limited to a very few components such as frame rails. 
Considering the fuel efficiency and GHG emissions reduction benefits 
that will be achieved by finalizing these rules in the time frame 
proposed, rather than delaying in order to gain enough information to 
include additional technologies, the agencies have decided to finalize 
standards that do not assume the use of these technologies and will 
consider incorporating them in a later action applicable to later model 
years. Cf. Sierra Club v. EPA, 325 F. 3d 374, 380 (DC Cir. 2003) (in 
implementing a technology-forcing provision of the CAA, EPA reasonably 
adopted modest initial controls on an industry sector in order to 
better assess rules' effects in preparation for follow-up rulemaking).
    As the program progresses and the agencies gather more information, 
we expect to reconsider whether vocational vehicle standards for MYs 
2019 and beyond should be based on the use of additional technologies 
besides low rolling resistance tires.
    EPA is adopting CO2 standards and NHTSA is finalizing 
fuel consumption standards for manufacturers of chassis for new 
vocational vehicles and for manufacturers of heavy-duty engines 
installed in these vehicles. The final heavy-duty engine standards for 
CO2 emissions and fuel consumption focus on potential 
technological improvements in fuel combustion and overall engine 
efficiency and those controls would achieve most of the emission 
reductions. Further reductions from the Class 2b-8 vocational vehicle 
itself are possible within the time frame of these final regulations. 
Therefore, the agencies are also finalizing separate standards for 
vocational vehicles that will focus on additional reductions that can 
be achieved through improvements in vehicle tires. The agencies' 
analyses, as discussed briefly below and in more detail later in this 
preamble and in the RIA Chapter 2, show that these final standards 
appear appropriate under each agency's respective statutory 
authorities. Together these standards are estimated to achieve 
reductions of up to 10 percent from most vocational vehicles.
    EPA is also adopting standards to control N2O and 
CH4 emissions from Class 2b-8 vocational vehicles through 
controlling these GHG emissions from the HD engines. The final heavy-
duty engine standards for both N2O and CH4 and 
details of the standard are included in the discussion in Section 
II.E.1.b and II.E.2.b. EPA neither proposed nor is adopting air 
conditioning leakage standards applying to vocational vehicle chassis 
manufacturers.
    As discussed further below, the agencies are setting CO2 
and fuel consumption standards for the chassis based on tire rolling 
resistance improvements and for the engines based on engine 
technologies. The fuel consumption and GHG emissions impact of tire 
rolling resistance is impacted by the mass of the vehicle. However, the 
impact of mass on rolling resistance is relatively small so the 
agencies proposed to aggregate several vehicle weight categories under 
a single category for setting the standards. The agencies proposed to 
divide the vocational vehicle segment into three broad regulatory 
subcategories--Light Heavy-Duty (Class 2b through 5), Medium Heavy-Duty 
(Class 6 and 7), and Heavy Heavy-Duty (Class 8) which is consistent 
with the nomenclature used in the diesel engine classification. The 
agencies received comments supporting the division of vocational 
vehicles into three regulatory categories from DTNA. The agencies also 
received comments from Bosch, Clean Air Task Force, and National Solid 
Waste Management Association supporting a finer resolution of 
vocational vehicle subcategories. Their concerns include that the 
agencies' vehicle configuration in GEM is not representative of a 
particular vocational application, such as refuse trucks. Another 
recommendation was to divide the category by both GVWR and by 
operational characteristics. Upon further consideration, the agencies 
are finalizing as proposed three vocational vehicle subcategories 
because we believe this adequately balances simplicity while still 
obtaining reductions in this diverse segment. (As noted in section IV.A 
below, these three subcategories also denominate separate averaging 
sets for purposes of ABT.) Finer distinctions in regulatory 
subcategories would not change the technology basis for the standards 
or the reductions expected from the vocational vehicle category. As the 
agencies move towards future heavy-duty fuel consumption and GHG 
regulations for post-2017 model years, we intend to gather GHG and fuel 
consumption data for specific vocational applications which could be 
used to establish application-specific standards in the future.
    The agencies received comments supporting the exclusion of 
recreational vehicles, emergency vehicles, school buses from the 
vocational vehicle standards. The commenters argued that these 
individual vehicle types were small contributors to overall GHG 
emissions and that tires meeting their particular performance needs 
might not be available by 2014. The agencies considered these comments 
and the agencies have met with a number of tire manufacturers to better 
understand their expectations for product availability for the 2014 
model year. Based on our review of the information shared, we are 
convinced that tires with rolling resistance consistent with our final 
vehicle standards and meeting the full range of other performance 
characteristics desired in the vehicle market, including for RVs, 
emergency vehicles, and school buses, will be broadly available by the 
2014 model year.\122\ Absent regulations for the vast majority of 
vehicles in this segment, feasible cost-effective reductions available 
at reasonable cost in the 2014-2018 model years will be needlessly 
foregone. Therefore, the agencies have decided to finalize the 
vocational vehicle standards as proposed with recreational vehicles, 
emergency vehicles and school buses included in the vocational vehicle 
category. As RVs were not included by NHTSA for proposed regulation, 
they are not within the scope of the NPRM and are therefore excluded in 
NHTSA's portion of the final program. NHTSA will revisit this issue in 
the next rulemaking. In developing the final standards, the agencies 
have evaluated the current levels of emissions and fuel consumption, 
the kinds of technologies that could be utilized by manufacturers to 
reduce emissions and fuel consumption and the associated lead time, the 
associated costs for the industry, fuel savings for the consumer, and 
the magnitude of the CO2 and fuel savings that may be 
achieved. After examining the possibility of vehicle improvements based 
on use of the technologies underlying the standards for Class 7 and 8 
tractors, including improved aerodynamics, vehicle speed limiters, idle 
reduction technologies, tire rolling resistance, and weight reduction, 
as well as use of hybrid technologies, the agencies ultimately

[[Page 57171]]

determined to base the final vehicle standards on performance of tires 
with superior rolling resistance. For standards for diesel engines 
installed in vocational vehicles, the agencies examined performance of 
engine friction reduction, aftertreatment optimization, air handling 
improvements, combustion optimization, turbocompounding, and waste heat 
recovery, ultimately deciding to base the final standards on the 
performance of all of the technologies except turbocompounding and 
waste heat recovery systems. The standards for gasoline engine 
installed in vocational vehicles are based on performance of 
technologies such as gasoline direct injection, friction reduction, and 
variable valve timing. The agencies' evaluation indicates that these 
technologies, as described in Section III.C, are available today in the 
heavy-duty tractor and light-duty vehicle markets, but have very low 
application rates in the vocational vehicle market. The agencies have 
analyzed the technical feasibility of achieving the CO2 and 
fuel consumption standards, based on projections of what actions 
manufacturers would be expected to take to reduce emissions and fuel 
consumption to achieve the standards, and believe that the standards 
are cost-effective and technologically feasible and appropriate within 
the rulemaking time frame. EPA and NHTSA also present the estimated 
costs and benefits of the vocational vehicle standards in Section III.
---------------------------------------------------------------------------

    \122\ Bachman, Joseph. Memorandum to the Docket. Heavy-Duty Tire 
Evaluation. See Docket EPA-HQ-OAR-2010-0162. Pages 2-3 and 
Appendix B.
---------------------------------------------------------------------------

(a) Vocational Vehicle Chassis Standards
    In the NPRM, the agencies defined tire rolling resistance as a 
frictional loss of energy, associated mainly with the energy dissipated 
in the deformation of tires under load that influences fuel efficiency 
and CO2 emissions. Tires with higher rolling resistance lose 
more energy in response to this deformation, thus using more fuel and 
producing more CO2 emissions in operation, while tires with 
lower rolling resistance lose less energy, and save more fuel and 
CO2 emissions in operation. Tire design characteristics 
(e.g., materials, construction, and tread design) influence durability, 
traction (both wet and dry grip), vehicle handling, ride comfort, and 
noise in addition to rolling resistance.
    The agencies explained that a typical Low Rolling Resistance (LRR) 
tire's attributes, compared to a non-LRR tire, would include increased 
tire inflation pressure; material changes; and tire construction with 
less hysteresis, geometry changes (e.g., reduced height to width aspect 
ratios), and reduction in sidewall and tread deflection. When a 
manufacturer applies LRR tires to a vehicle, the manufacturer generally 
also makes changes to the vehicle's suspension tuning and/or suspension 
design in order to maintain vehicle handling and ride comfort.
    The agencies also explained that while LRR tires can be applied to 
vehicles in all MD/HD classes, they may have special potential for 
improving fuel efficiency and reducing CO2 emissions for 
vocational vehicles. According to an energy audit conducted by Argonne 
National Lab, tires are the second largest contributor to energy losses 
of vocational vehicles, after engines.\123\ Given this finding, the 
agencies considered the availability of LRR tires for vocational 
applications by examining the population of tires available, and 
concluded that there appeared to be few LRR tires for vocational 
applications. The agencies suggested in the NPRM that this low number 
of LRR tires for vocational vehicles could be due in part to the fact 
that the competitive pressure to improve rolling resistance of 
vocational vehicle tires has been less than in the line haul tire 
market, given that line haul vehicles generally drive significantly 
more miles and therefore have significantly higher operating costs for 
fuel than vocational vehicles, and much greater incentive to improve 
fuel consumption. The small number of LRR tires for vocational vehicles 
may perhaps also be due in part to the fact that vocational vehicles 
generally operate more frequently on secondary roads, gravel roads and 
roads that have less frequent winter maintenance, which leads 
vocational vehicle buyers to value tire traction and durability more 
than rolling resistance. The agencies recognized that this provided an 
opportunity to improve fuel consumption and GHG emissions by creating a 
regulatory program that encourages improvements in tire rolling 
resistance for both line haul and vocational vehicles. The agencies 
proposed to base standards for all segments of HD vehicles on the use 
of LRR tires. The agencies estimated that a 10 percent reduction in 
average tire rolling resistance would be attainable between model years 
2010 and 2014 based on the tire development achievements over the last 
several years in the line haul truck market. This reduction in tire 
rolling resistance would correlate to a two percent reduction in fuel 
consumption as modeled by the GEM.\124\
---------------------------------------------------------------------------

    \123\ A Class 6 pick up and delivery truck at 50% load has tires 
as the second largest contributor at speeds up to 35 mph, a typical 
average speed of urban delivery vehicles. See Argonne National 
Laboratory. ``Evaluation of Fuel Consumption Potential of Medium and 
Heavy Duty Vehicles through Modeling and Simulation.'' October 2009. 
Page 91.
    \124\ See 75 FR at 74241.
---------------------------------------------------------------------------

(i) Summary of Comments
    The agencies received many comments on the subject of tire rolling 
resistance as applied to vocational vehicles. Comments included 
suggestions for alternative test procedures; whether LRR tires should 
be applied to certain types of vocational vehicles and whether certain 
vehicles should be exempted from the vocational vehicle standards if 
the standards are based on the ability to use LRR tires; the 
appropriateness of the proposed standards; and compliance issues 
(discussed below in Section II.D.2.b.
    Regarding whether LRR tires should be applied to certain types of 
vocational vehicles, the agencies received many comments from 
stakeholders, such as Daimler Trucks North America, Fire Apparatus 
Manufacturers Association (FAMA), International Association of Fire 
Chiefs, National Ready Mix, National Solid Wastes Management 
Association (NSWMA), Spartan Motors, National Automobile Dealers 
Association, among others. There were comments regarding applicability 
of low rolling resistance tires to vocational vehicles based on LRR 
tire availability, suitability of the tires for the applications, fuel 
consumption and GHG emissions benefits and the appropriateness of 
standards. Many of these commenters focused particularly on the whether 
LRR tires would compromise the capability of emergency vehicles.
    Regarding whether LRR tires are available in the market for certain 
vocational vehicles and whether the vocational vehicle standards were 
therefore appropriate and feasible, both Ford and AAPC stated that the 
proposed model-based requirement for Class 2b-8 vocational chassis 
appeared to require tires with rolling resistance values of 
approximately 8.0-8.1 kg/metric ton or better, and that limited data 
available for smaller diameter tires, such as light-truck (LT) tires 
used on many light heavy-duty trucks and vans, suggested that there 
exist few if any choices for tires that would comply. Given this 
concern about the availability of compliant tires, particularly in the 
case of tires smaller than 22.5'', during the proposed regulatory time 
frame, AAPC and Ford requested revisions to the requirement, or the 
modeling method, to establish different standards for vehicles

[[Page 57172]]

that use different tire classes, with separate requirements for LT 
tires, 19.5'' tires, and 22.5'' tires. AAPC argued that standards 
should be set based on data collected on high volume in-use tires, and 
that they should be set at a level that ensures the availability of 
multiple compliant tires. CRR
(ii) Summary of Research Done Since the Notice of Proposed Rulemaking
    Since the NPRM, the agencies have conducted additional research on 
tire rolling resistance for medium- and heavy-duty applications. This 
research involved direct discussions with tire suppliers,\125\ 
assessment of the comments received, additional review of tire products 
available, and a more thorough review of tire use in the field. In 
addition, EPA has conducted tire rolling resistance testing to help 
inform the final rulemaking.\126\
---------------------------------------------------------------------------

    \125\ Records of these communications, and additional 
information submitted by the supplier companies and not CBI, are 
available at Docket No. EPA-HQ-OAR-2010-0162.
    \126\ Bachman, Joseph. Memorandum to the Docket. Heavy-Duty Tire 
Evaluation. July 2011. Docket EPA-HQ-OAR-2010-0162, Pages 3-6.
---------------------------------------------------------------------------

    The agencies discussed many aspects of low rolling resistance tire 
technologies and their application to vocational vehicles with tire 
suppliers since publication of the NPRM. Several tire suppliers 
indicated to the agencies that low rolling resistance tires are 
currently available for vocational applications that would enable 
compliance with the proposed vocational vehicle standards, such as 
delivery vehicles, refuse vehicles, and other vocations. However, these 
conversations also made the agencies aware that availability of low 
rolling resistance tires varies by supplier. Some suppliers stated they 
focused their company resources on areas of the medium- and heavy-duty 
vehicle spectrum where fleet operators would see the most fuel 
efficiency benefits for the application of low rolling resistance 
technologies; specifically the long-haul, on-highway applications that 
drive many miles and use large amounts of fuel. These suppliers stated 
that this choice was driven by the significant capital investment that 
would be needed to improve tire rolling resistance across the 
relatively large number of product offerings in the vocational vehicle 
segment, based on the wide range of tire sizes, load ratings, and speed 
ratings, compared to the much narrower range of offerings for long-haul 
applications.\127\ Other suppliers stated that they have made conscious 
efforts to reduce the rolling resistance of all of their medium- and 
heavy-duty vehicle tire offerings, including vocational applications, 
in an effort to become leaders in this technology.
---------------------------------------------------------------------------

    \127\ More tire types and sizes have been developed for 
vocational vehicle applications than for long-haul applications. In 
some cases, suppliers offer up to 17 different vocational tire 
designs, and for each design there may be 8-10 different tire sizes. 
In contrast, a line-haul application may have only 2-3 tire designs 
with a fewer range of sizes.
---------------------------------------------------------------------------

    The agencies also discussed with tire suppliers the potential tire 
attribute tradeoffs that may be associated with incorporating designs 
that improve tire rolling resistance, given the driving patterns, 
environmental conditions, and on-road and off-road surface conditions 
that vocational vehicles are subjected to. Some vehicle manufacturer 
commenters had suggested that changes in tire tread block design that 
improve rolling resistance may adversely affect tire performance 
characteristics such as traction, resistance to tearing, and resistance 
to wear and damage from scrubbing on curbs and frequent tight radius 
turns that are important to customers for vocational vehicle 
performance. The suppliers agreed that providing tires unable to 
withstand these conditions or meet the vehicle application needs would 
adversely affect customer satisfaction and warranty expenses, and would 
have detrimental financial effects to their businesses. One supplier 
indicated that theoretically, tread-wear (tire life) could be 
compromised if suppliers choose to reduce the initial tire tread depth 
without any offsetting tire compound or design enhancements as the 
means to achieve rolling resistance reductions. That supplier argued 
that taking this approach could lead to more frequent tire replacements 
or re-treading of existing tire carcasses, and that the agencies should 
therefore take a total lifecycle view when evaluating the effects of 
driving rolling resistance reductions. That supplier also indicated 
that a correlation of a 20 percent reduction in rolling resistance 
achieved through tread depth reduction could lead to a 30 percent 
decrease in tread-life and 15 percent reduction in wet traction. The 
agencies note that when they inquired about potential `safety' related 
tradeoffs, such as traction (braking and handling) and tread wear when 
applying low rolling resistance technologies, tire suppliers which 
remain subject to safety standards regardless of this program, 
consistently responded that they would not produce a tire that 
compromises safety when fitted in its proper application.
    In addition to the supplier discussions and evaluation of comments 
to the Notice of Proposed Rulemaking, EPA conducted a series of tire 
rolling resistance tests on medium- and heavy-duty vocational vehicle 
tires. The testing measured the CRR of tires representing 16 different 
vehicle applications for Class 4-8 vocational vehicles. The testing 
included approximately 5 samples each of both steer and drive tires for 
each application. The tests were conducted by two independent tire test 
labs, Standards Testing Lab (STL) and Smithers-Rapra (Smithers).
    Overall, a total of 156 medium- and heavy-duty tires\128\ were 
included in this testing, which was comprised of 88 tires covering 
various commercial vocational vehicle types, such as bucket trucks, 
school buses, city delivery vehicles, city transit buses and refuse 
haulers among others; 47 tires intended for application to tractors; 
and 21 tires classified as light-truck (LT) tires intended for Class 4 
vocational vehicles such as delivery vans. In addition, approximately 
20 of the tires tested were exchanged between the labs to assess inter-
laboratory variability.
---------------------------------------------------------------------------

    \128\ After the agencies completed their analysis of these data, 
the agencies received raw data on 43 additional tires. See Powell, 
Greg. Memorandum to the Docket. Additional Tire Testing Results. 
July 2011. Docket NHTSA-2010-0079. The agencies have not analyzed 
these additional data, nor included them in the final report, and 
the data therefore played no role in the agencies' determination of 
an appropriate standard for vocational vehicles. The agencies will 
analyze and consider these data, along with any future data received 
through continued testing, as appropriate, in the next rulemaking 
for the heavy duty sector.
---------------------------------------------------------------------------

    The test results for 88 commercial vocational vehicle tires (19.5'' 
and 22.5'' sizes) showed a test average CRR of 7.4 kg/metric ton, with 
results ranging from 5.1 to 9.8. To comply with the proposed vocational 
vehicle fuel consumption and GHG emissions standards using improved 
tire rolling resistance as the compliance strategy, a manufacturer 
would need to achieve an average tire CRR value of 8.1 kg/metric 
ton.\129\ The measured average CRR of 7.4kg/metric ton is thus better 
than the average value that would be needed to meet vocational vehicle 
standards. Of those 173 tires tested, twenty tires had CRR values 
exceeding 8.1 kg/metric ton, two were at 8.1 kg/metric ton, and sixty-
six tires were better than 8.1 kg/metric ton. Additional data analyses 
examining the tire data by tire size to determine the range and 
distribution of CRR values within each tire size showed each tire size 
generally had tires ranging from approximately 6.0 to 8.5 kg/metric 
ton, with a small number of tires in the 5.3-5.7 kg/metric ton range 
and a small

[[Page 57173]]

number of tires in a range as high as 9.3-9.8 kg/ton. Review of the 
data showed that for each tire size and vehicle type, the majority of 
tires tested would enable compliance with vocational vehicle fuel 
consumption and GHG emission standards.
---------------------------------------------------------------------------

    \129\ See 75 FR at 74244.
---------------------------------------------------------------------------

    The test results for the 47 tires intended for tractor application 
showed an overall average of 6.9 kg/ton, the lowest overall average 
rolling resistance of the different tire applications tested.\130\ This 
is consistent with what the agencies heard through comments and 
meetings with tire suppliers whose efforts have focused on tractor 
applications, particularly for long-haul applications, which yield the 
highest fuel efficiency benefits from LRR tire technology.
---------------------------------------------------------------------------

    \130\ The CRR values for these applications ranged from 5.4 to 
9.2 kg/metric ton.
---------------------------------------------------------------------------

    Finally, the 21 LT tires intended for Class 4 vocational vehicles 
were comprised of two sizes; LT225/75R16 and LT245/75R16 with 11 and 10 
samples tested, respectively. Some auto manufacturers have indicated 
that CRR values for tires fitted to these Class 4 vehicles typically 
have a higher CRR values than tires found on commercial vocational 
vehicles because of the smaller diameter wheel size and the ISO testing 
protocol.\131\ The test data showed the average CRR for LT225/75R16 
tires was 9.1 kg/metric ton and the average for LT245/75R16 tires was 
8.6 kg/metric ton. The range for the LT225/75R16 tires spanned 7.4 to 
11.0 \132\ and the range for the LT245/75R16 tires ranged from 6.6 to 
9.8 kg/metric ton. Overall, the average for the tested LT tires was 8.9 
kg/metric ton.
---------------------------------------------------------------------------

    \131\ See comments to docket EPA-HQ-OAR-2010-0162-1761; Ford 
Motor Company
    \132\ The agency notes the highest CRR values recorded for LT 
tires, of 11.0 and 10.9, were for two tires of the same size and 
brand. The nearest recorded values to these two tires were 9.8; 
substantially beyond the differences between other tires tested.
---------------------------------------------------------------------------

    Analysis of the EPA test data for all vocational vehicles, 
including LT tires, shows the test average CRR is 7.7 kg/metric ton 
with a standard deviation of 1.2 kg/metric ton. Review of the data thus 
shows that for each tire size and vehicle type, there are many tires 
available that would enable compliance with the proposed standards for 
vocational vehicles and tractors except for LT tires for Class 4 
vocational vehicles where test results show the majority of these tires 
have CRR worse than 8.1 kg/metric ton.
    The agencies also reviewed the CRR data from the tires that were 
tested at both the STL and Smithers laboratories to assess inter-
laboratory and test machine variability. The agencies conducted 
statistical analysis of the data to gain better understanding of lab-
to-lab correlation and developed an adjustment factor for data measured 
at each of the test labs. When applied, this correction factor showed 
that for 77 of the 80 tires tested, the difference between the original 
CRR and a value corrected CRR was 0.01 kg/metric ton. The values for 
the remaining three tires were 0.03 kg/metric ton, 0.05 kg/metric ton 
and 0.07 kg/metric ton. Based on these results, the agencies believe 
the lab-to-lab variation for the STL and Smithers laboratories would 
have very small effect on measured CRR values. Further, in analyzing 
the data, the agencies considered both measurement variability and the 
value of the measurements relative to proposed standards. The agencies 
concluded that although laboratory-to-laboratory and test machine-to-
test machine measurement variability exists, the level observed is not 
excessive relative to the distribution of absolute measured CRR 
performance values and relative to the proposed standards. Based on 
this, the agencies concluded that the test protocol is reasonable for 
this program, but are making some revisions to the vehicle standards.
    The agencies also conducted a winter traction test of 28 tires to 
evaluate the impact of low rolling resistance designs on winter 
traction. The results of the study indicate that there was no 
statistical relationship between rolling resistance and snow 
traction.\133\
---------------------------------------------------------------------------

    \133\ Bachman, Joseph. Memorandum to Docket. Heavy-Duty Tire 
Evaluation. Docket EPA-HQ-OAR-2010-0162. Pages 3-6.
---------------------------------------------------------------------------

(iii) Summary of Final Rules
    For vocational vehicles, the agencies intend to keep rolling 
resistance as an input to the GEM but with modifications to the 
proposed targets as a result of the testing completed by EPA since the 
NPRM and information from tire suppliers. The agencies continue to 
believe that LRR tires, which are an available, cost-effective, and 
appropriate technology with demonstrated fuel efficiency and GHG 
reduction benefits, are reasonable for all on-highway vehicles.
    The agencies acknowledge there can be tradeoffs when designing a 
tire for reduced rolling resistance. These tradeoffs can include 
characteristics such as wear resistance, cost and scuff resistance. 
However, the agencies have continued to review this issue and do not 
believe that LRR tires as specified in the rules present safety issues. 
The agencies continue to believe that LRR tires, which are an 
available, cost-effective, and appropriate technology with demonstrated 
fuel efficiency and GHG reduction benefits, are reasonable for all on-
highway vehicles. The final program also provides exemptions for 
vehicles meeting ``low-speed'' or ``off-road'' criteria, including 
application of speed restricted tires. Vocational vehicles that have 
speed restricted tires in order to accommodate particular applications 
may be exempted from the program under the off-road or low-speed 
exemption, described in greater detail below in Section 
II.D.(1)(a)(iv).
    As just noted, the agencies conducted independent testing of 
current tires available to assist confirming the finalized rolling 
resistance standards. The tire test samples were selected from those 
currently available on the market and therefore have no known safety 
issues and meet all current requirements to allow availability in 
commerce; including wear, scuff resistance, braking, traction under wet 
or icy conditions, and other requirements. These tires included a wide 
array of sizes and designs intended for most all vocational 
applications, including those used for school buses, refuse haulers, 
emergency vehicles, concrete mixers, and recreational vehicles. As the 
test results revealed, there are a significant number of tires 
available that meet or do better than the rolling resistance targets 
for vocational vehicles; both light-truck (with an adjustment factor 
described later in this preamble section) and non-LT tire types, while 
meeting all applicable safety standards.
    The agencies also recognize the extreme conditions fire apparatus 
equipment must navigate to enable firefighters to perform their duties. 
As described below, the final rules contain provisions to allow for 
exemption of specific off-road capable vocational vehicles from the 
fuel efficiency and greenhouse gas standards. Included in the exemption 
criteria are provisions for vehicles equipped with specific tire types 
that would be fit to a vehicle to meet extreme demands, including those 
vehicles designed for off-road capability.
    As follow-up to the final rules and in support for development of a 
separate FMVSS rule, NHTSA plans to conduct additional performance-
focused testing (beyond rolling resistance) for medium- and heavy-duty 
trucks. This testing is targeted for completion toward the end of this 
year. The agencies will review these performance data when available, 
in concert with any subsequent proposed rulemakings regarding fuel 
consumption and GHG emissions

[[Page 57174]]

standards for medium- and heavy-duty vehicles.
    For vocational vehicles, the rolling resistance of each tire will 
be measured using the ISO 28850 test method for drive tires and steer 
tires planned for fitment to the vehicle being certified. Once the test 
CRR values are obtained, a manufacturer will input the CRR values for 
the drive and steer tires separately into the GEM where, for vocational 
vehicles, the vehicle load is distributed equally over the steer and 
drive tires. Once entered, the amount of GHG reduction attributed to 
tire rolling resistance will be incorporated into the overall vehicle 
compliance value. The following table provides the revised target CRR 
values for vocational vehicles for 2014 and 2017 model years that are 
used to determine the vehicle standards.

    Table II-14--Vocational Vehicle--Target CRR Values for GEM Input
------------------------------------------------------------------------
                                        2014 MY             2017 MY
------------------------------------------------------------------------
Tire Rolling Resistance (kg/      7.7 kg/metric ton.  7.7 kg/metric ton
 metric ton).
------------------------------------------------------------------------

    These target values are being revised based on the significant 
availability of tires for vocational vehicles applications which have 
performance better than the originally proposed 8.1 kg/metric ton 
target. As just discussed, 63 of the 88 tires tested for vocational 
applications had CRR values better than the proposed target. The tires 
tested covered fitment to a wide range of vocational vehicle types and 
classes; thus agencies believe the original target value of 8.1 kg/
metric ton was possibly too lenient after reviewing the testing data. 
Therefore, the agencies believe it is appropriate to reduce the 
proposed vehicle standard based on performance of a CRR target value of 
7.7 kg/metric ton for non-LT tire type. As discussed previously, this 
value is the test average of all vocational tires tested (including LT) 
which takes a conservative approach over setting a target based on the 
average of only the non-LT vocational tires tested. For LT tires, based 
on both the test data and the comments from AAPC and Ford Motor 
Company, the agencies recognize the need to provide an adjustment. In 
lieu of having two sets of Light Heavy-Duty vocational vehicle 
standards, the agencies are finalizing an adjustment factor which 
applies to the CRR test results for LT tires. The agencies developed an 
adjustment factor dividing the overall vocational test average CRR of 
7.7 by the LT vocational average of 8.9. This yields an adjustment 
factor of 0.87. For LT vocational vehicle tires, the measured CRR 
values will be multiplied by the 0.87 adjustment factor before entering 
the values in the GEM for compliance.
    Based on the tire rolling resistance inputs noted above, EPA is 
finalizing the following CO2 standards for the 2014 model 
year for the Class 2b through Class 8 vocational vehicle chassis, as 
shown in Table II-15. Similarly, NHTSA is finalizing the following fuel 
consumption standards for the 2016 model year, with voluntary standards 
beginning in the 2014 model year. For the EPA GHG program, the standard 
applies throughout the useful life of the vehicle. The agencies note 
that both the baseline performance and standards derived for the final 
rules slightly differ from the values derived for the NPRM. The first 
difference is due to the change in the target rolling resistance from 
8.1 to 7.7 kg/metric ton based on the agencies' test results. Second, 
there are minor differences in the fuel consumption and CO2 
emissions due to the small modifications made to the GEM, as noted in 
RIA Chapter 4. Lastly, the final HHD vocational vehicle standard uses a 
revised payload assumption of 15,000 pounds instead of the 38,000 
pounds used in the NPRM, as described in Section II.D.3.c.iii. As a 
result, the emission standards shown in Table II-15 for vocational 
vehicles have changed from the standards published in the NPRM. The 
changes for light heavy and medium heavy-duty vehicles are modest. The 
change for heavy heavy-duty vocational vehicles is larger, due to the 
difference in assumed payload.
    As with the 2017 MY standards for Class 7 and 8 tractors, EPA and 
NHTSA are adopting more stringent vocational vehicle standards for the 
2017 model year which reflect the CO2 emissions reductions 
required through the 2017 model year engine standards. See also Section 
II.B.2 explaining the same approach for the standards for combination 
tractors. As explained in Section 0 below, engine performance is one of 
the inputs into the GEM compliance model that has a pre-defined (i.e. 
fixed) value established by the agencies, and that input will change in 
the 2017 MY to reflect the 2017 MY engine standards. The 2017 MY 
vocational vehicle standards are not premised on manufacturers 
installing additional vehicle technologies, and a vocational vehicle 
that complies with the standards in MY 2016 will also comply in MY 2017 
with no vehicle (tire) changes. Thus, although chassis manufacturers 
will not be required to make further improvements in the 2017 MY to 
meet the standards, the standards will be more stringent to reflect the 
engine improvements required in that year. This is because in 2017 MY 
GEM vehicle modeling outputs (in grams per ton mile and gallons per 
1,000 ton mile) will automatically decrease since engine efficiency 
will improve in that year.

               Table II-15--Final Class 2b-8 Vocational Vehicle CO2 and Fuel Consumption Standards
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
                           EPA CO2 (gram/ton-mile) Standard Effective 2014 Model Year
----------------------------------------------------------------------------------------------------------------
                                       Light Heavy-Duty Class   Medium Heavy-Duty Class  Heavy Heavy-Duty Class
                                        2b-5.                    6-7.                     8
----------------------------------------------------------------------------------------------------------------
CO2 Emissions........................  388....................  234....................  226
----------------------------------------------------------------------------------------------------------------
           NHTSA Fuel Consumption (gallon per 1,000 ton-mile) Standard Effective 2016 Model Year \134\
----------------------------------------------------------------------------------------------------------------
                                       Light Heavy-DutyClass    Medium Heavy-Duty Class  Heavy Heavy-Duty Class
                                        2b-5.                    6-7.                     8
----------------------------------------------------------------------------------------------------------------
Fuel Consumption.....................  38.1...................  23.0...................  22.2
----------------------------------------------------------------------------------------------------------------
                           EPA CO2 (gram/ton-mile) Standard Effective 2017 Model Year
----------------------------------------------------------------------------------------------------------------
                                       Light Heavy-Duty Class   Medium Heavy-Duty Class  Heavy Heavy-Duty Class
                                        2b-5.                    6-7.                     8
----------------------------------------------------------------------------------------------------------------
CO2 Emissions........................  373....................  225....................  222
----------------------------------------------------------------------------------------------------------------

[[Page 57175]]

 
                 NHTSA Fuel Consumption (gallon per ton-mile) Standard Effective 2017 Model Year
----------------------------------------------------------------------------------------------------------------
                                       Light Heavy-Duty Class   Medium Heavy-Duty Class  Heavy Heavy-Duty Class
                                        2b-5.                    6-7.                     8
----------------------------------------------------------------------------------------------------------------
Fuel Consumption.....................  36.7...................  22.1...................  21.8
----------------------------------------------------------------------------------------------------------------

(iv) Off-Road and Low-Speed Vocational Vehicle Standards
    Some vocational vehicles, because they are primarily designed for 
off-road use, may not be good candidates for low rolling resistance 
tires. These vehicles may travel on-road for very limited periods of 
time, such as in traveling on an urban road, or if they are off-loaded 
from another vehicle onto a road and then are driven off-road. The 
infrequent and limited exposure to on-road environments makes these 
vehicles suitable candidates for providing an exemption from the 
CO2 emissions and fuel consumption standards for vocational 
vehicles (although the standards for HD engines used in vocational 
vehicles would still apply).\135\ The agencies are also targeting other 
vehicles that travel at low speeds and that are meant to be used both 
on- and off-road. The application of certain technologies to these 
vehicles may not provide the same level of benefits as it would for 
pure on-road vehicles, and moreover, could even reduce the 
functionality of the vehicle. In this case, the agencies want to ensure 
that vehicle functionality is maintained to the maximum extent 
possible, while avoiding the possibility that achievable benefits are 
not realized because of the structure of the regulations. The sections 
below explain this issue in more detail as it applies to tractors and 
vocational vehicles.
---------------------------------------------------------------------------

    \134\ Manufacturers may voluntarily opt-in to the NHTSA fuel 
consumption program in 2014 or 2015. Once a manufacturer opts into 
the NHTSA program it must stay in the program for all the optional 
MYs.
    \135\ See 75 FR at 74199.
---------------------------------------------------------------------------

    The agencies explained in the NPRM that certain vocational vehicles 
have very limited on-road usage, and that although they would be 
defined as ``motor vehicles'' per 40 CFR 85.1703, the fact that they 
spend the most of their operations off-road might be reason for 
excluding them from the vocational vehicle standards. Vocational 
vehicles, such as those used on oil fields and construction sites,\136\ 
experience very little benefit from LRR tires or from any other 
technologies to reduce GHG emissions and fuel consumption. The agencies 
proposed to allow a narrow range of these de facto off-road vehicles to 
be excluded from the proposed vocational vehicle standards if equipped 
with special off-road tires having lug type treads. The agencies stated 
in the NPRM that on/off road traction is the only tire performance 
parameter which trades off with TRR so significantly that tire 
manufacturers could be unable to develop tires meeting both a TRR 
standard while maintaining or improving the characteristic allowing 
them to perform off-road. See generally 75 FR at 74199-200. Therefore, 
the agencies proposed to exempt these vehicles from the standards while 
requiring them to use certified engines, which would provide fuel 
consumption and CO2 emission reductions in all vocational 
applications. To ensure that these vehicles were in fact used chiefly 
off-road, the agencies proposed requirements that would allow exemption 
of a vehicle provided the vehicle and the tires were speed restricted. 
As mentioned, the agencies were aware that the majority of off road 
trucks primarily use off-road tires and are low speed vehicles as well. 
Based upon this understanding, the agencies specifically proposed that 
a vehicle must meet the following requirements to qualify for an 
exemption from vocational vehicle standards:
---------------------------------------------------------------------------

    \136\ Vehicles such as concrete mixers, off-road dump trucks, 
backhoes and wheel loaders.
---------------------------------------------------------------------------

     Tires which are lug tires or contain a speed rating of 
less than or equal to 60 mph; and
     A vehicle speed limiter governed to 55 mph.
    In response to the NPRM, EMA/TMA, Navistar and Volvo agreed with 
the proposal to exclude off-road vocational vehicles from the standards 
because these vehicles primarily operate off-road, but requested 
broadening the exclusion to cover other types of vocational vehicles. 
Several manufacturers (IAFC, FAMA, NTEA, NSWMA, AAPC, RMA, Navistar and 
DTNA) requested the exemption of specific vehicle types, such as on/
off-road emergency vehicles, refuse vehicles, low speed transit buses 
or school buses, because their usage was viewed as being incompatible 
with LRR tires. Navistar opposed the application of the proposed 
regulations to school buses, arguing that LRR tires may impact the ride 
quality for children in school buses. However, Navistar also 
acknowledged that a significant portion of the national fleet of school 
buses already utilizes off-road tires designed with lug type tread 
patterns (e.g., Kentucky). IAFC, FAMA and NTEA commented that fire 
trucks and ambulances should also be exempted due to their part-time 
off-road use such as in responding to a wildland fire or hazardous 
materials incidents which would require operations on dirt and gravel 
roads, fields or other off-road environments. Commenters also contended 
that by requiring a 55-mph limitation, the proposed exemption would be 
impractical for emergency vehicles due to the need to respond quickly 
to life-threatening events. The refuse truck manufacturers and trade 
associations, NSWMA and AAPC, commented that the solid waste industry 
operates a variety of vocational vehicles that perform solely off-road 
at landfills. These comments also requested an exemption for certain 
refuse trucks (i.e., roll-off container trucks) that frequently go off-
road at construction sites. Other commenters (FAMA, IAFC and Oshkosh) 
opposed compliance with the LRR standard for vocational vehicles for 
on/off road mixed service tires with aggressive or lug treads, stating 
that up to this point the industry has had very little interest in 
improving the LRR aspects of these tires or even to conducting testing 
to determine values for the coefficient of rolling resistance.
    For the final rules, the agencies have considered the issues raised 
by commenters and have decided to adopt different criteria than 
proposed for exempting vocational vehicles and vocational tractors that 
primarily travel off-road. The agencies believe that the reasons for 
proposing the exemption are equally applicable to a wider class of 
vocational vehicles operating mostly off-road so that the proposals 
were either unsuitable for the industry or too restrictive to capture 
all the vehicles intended for the exemption. For example, the NPRM 
proposal, by using tire tread patterns and VSLs as the basis for 
qualifying vehicles for the exemption, was too restrictive because 
other non-lug type tread patterns exist in the market as well as other 
technologies which are equally capable of limiting the speed of the 
vehicle, as mentioned by Volvo. Therefore, the

[[Page 57176]]

proposed exemption for off-road vocational vehicles will be replaced 
with new criteria based on the vehicle application, whether it operates 
at low speed and whether the vehicle has speed restricted tires. The 
exemption is in part based on existing industry standards established 
by NHTSA.\137\ As such, any vocational vehicle including vocational 
tractors primarily used off-road or at low speeds must meet the 
following criteria to be exempt from GHG and fuel consumption vehicle 
standards:
---------------------------------------------------------------------------

    \137\ The heavy-duty off-road exemption is based in part on 
requirements existing in NHTSA's Federal Motor Vehicle Safety 
Standards (FMVSS) Nos. 119 and 121. In FMVSS No. 119, titled ``New 
pneumatic tires for motor vehicles with a GVWR of more than 4,538 
kilograms (10,000 pounds) and motorcycles,'' speed restricted tires 
rated at a speed of 55 mph or less are subjected to lower test drum 
speeds in the endurance test to account for their low design speeds 
(e.g., off-road tires). The off-road vehicle exemptions adopted for 
this heavy-duty program were based on the requirements used in FMVSS 
No. 121, ``Air brake systems,'' to identify and exclude vocational 
vehicles based upon their inability to meet on-highway stopping 
distance requirements.
---------------------------------------------------------------------------

     Any vehicle primarily designed to perform work off-road 
such as in oil fields, forests, or construction sites and having 
permanently or temporarily affixed components designed to work in an 
off-road environment (i.e., hazardous material equipment or off-road 
drill equipment) or vehicles operating at low speeds making them 
unsuitable for normal highway operation; and meeting one or more of the 
following criteria:
     Any vehicle equipped with an axle that has a gross axle 
weight rating (GAWR) of 29,000 pounds; or
     Any truck or bus that has a speed attainable in 2 miles of 
not more than 33 mph; or
     Any truck that has a speed attainable in 2 miles of not 
more than 45 mph, an unloaded vehicle weight that is not less than 95 
percent of its gross vehicle weight rating (GVWR), and no capacity to 
carry occupants other than the driver and operating crew.
    The agencies are also adopting in the final rules provisions to 
exempt any vocational vehicle that can operate in both on and off-road 
environments and has speed restricted tires rated at 55 mph or 
below.\138\ The agencies' reasoning in adopting a speed restricted 
exemption for tires is that the majority of mixed service tires used 
for off-road use was identified as being restricted at 55 mph or 
less.\139\ Also, as identified by FMVSS No. 119, speed restricted tires 
at a rating of 55 mph or less are incapable of meeting the same on-road 
performance standards as conventional tires. The agencies acknowledge 
that using a speed restriction criteria could allow certain vehicles to 
be exempted inappropriately (i.e., low speed city delivery tractors) 
but the agencies believe this is preferable to creating a situation 
where a segment of vehicles are precluded from performing their 
intended applications. Therefore, the final rules include an exemption 
for any mixed service (on and off-road) vocational vehicle equipped 
with off-road tires that are speed restricted at 55 mph or less.
---------------------------------------------------------------------------

    \138\ See 40 CFR 1037.631.
    \139\ Particular tire use was identified during the FMVSS 119 
rulemaking and confirmed through subsequent market research. See 
``2010 Year Book the Tire and RIM Association Inc.''
---------------------------------------------------------------------------

    Manufacturers choosing to exempt vehicles based on the above 
criteria will be required to provide a description of how they meet the 
qualifications for each vehicle family group in their end-of-the year 
and final year reports (see Section V).
    A manufacturer having an off-road vehicle failing to meet the 
criteria under the agencies' off-road exemptions will be allowed to 
submit a petition describing how and why their vehicles should qualify 
for exclusion. The process of petitioning for an exemption is explained 
in Sec.  1037.631 and Sec.  535.8. For each request, the manufacturer 
will be required to describe why it believes an exemption is warranted 
and address the following factors which the agencies will consider in 
granting its petition:
     The agencies provide an exemption based on off-road 
capability of the vehicle or if the vehicle is fitted with speed 
restricted tires. Which exemption does your vehicle qualify under; and
     Are there any comparable tires that exist in the market to 
carry out the desired application both on and off road for the subject 
vehicle(s) of the petition which have LLR values that would enable 
compliance with the standard?
(b) Heavy-Duty Engine Standards for Engines Installed in Vocational 
Vehicles
    EPA is finalizing GHG standards \140\ and NHTSA is finalizing fuel 
consumption standards for new heavy-duty engines installed in 
vocational vehicles. The standards will vary depending on whether the 
engines are diesel or gasoline powered since emissions and fuel 
consumption profiles differ significantly depending on whether the 
engine is gasoline or diesel powered. The agencies' analyses, as 
discussed briefly below and in more detail later in this preamble and 
in the RIA Chapter 2, show that these standards are appropriate and 
feasible under each agency's respective statutory authorities.
---------------------------------------------------------------------------

    \140\ Specifically, EPA is finalizing CO2, 
N2O, and CH4 emissions standards for new 
heavy-duty engines over an EPA specified useful life period (See 
Section 0 for the N2O and CH4 standards).
---------------------------------------------------------------------------

    The agencies have analyzed the feasibility of achieving the GHG and 
fuel consumption standards, based on projections of what actions 
manufacturers are expected to take to reduce emissions and fuel 
consumption. EPA and NHTSA also present the estimated costs and 
benefits of the heavy-duty engine standards in Section III below. In 
developing the final rules, the agencies have evaluated the kinds of 
technologies that could be utilized by engine manufacturers compared to 
a baseline engine, as well as the associated costs for the industry and 
fuel savings for the consumer and the magnitude of the GHG and fuel 
consumption savings that may be achieved.
    EPA's existing criteria pollutant emissions regulations for heavy-
duty highway engines establish four service classes (three for 
compression-ignition or diesel engines and one for spark ignition or 
gasoline engines) that represent the engine's intended and primary 
vehicle application, as shown in Table II-16 (40 CFR 1036.140 and 
NHTSA's 49 CFR 535.4). The agencies proposed to use the existing 
service classes to define the engine subcategories in this HD GHG 
emissions and fuel consumption program. The agencies did not receive 
any adverse comments to using this approach. Thus, the agencies are 
adopting the four engine subcategories for this final action.

              Table II-16--Engine Regulatory Subcategories
------------------------------------------------------------------------
            Engine category                    Intended application
------------------------------------------------------------------------
Light Heavy-duty (LHD) Diesel..........  Class 2b through Class 5 trucks
                                          (8,501 through 19,500 pounds
                                          GVWR).
Medium Heavy-duty (MHD) Diesel.........  Class 6 and Class 7 trucks
                                          (19,501 through 33,000 pounds
                                          GVWR).
Heavy Heavy-duty (HHD) Diesel..........  Class 8 trucks (33,001 pounds
                                          and greater GVWR.
Gasoline...............................  Incomplete vehicles less than
                                          14,000 pounds GVWR and all
                                          vehicles (complete or
                                          incomplete) greater than
                                          14,000 pounds GVWR.
------------------------------------------------------------------------

(i) Diesel Engine Standards for Engines Installed in Vocational 
Vehicles
    In the NPRM, the agencies proposed the following CO2 and 
fuel consumption standards for HD diesel engines to be

[[Page 57177]]

installed in vocational vehicles, as shown in Table II-17.

                  Table II-17--Vocational Diesel Engine Standards Over the Heavy-Duty FTP Cycle
----------------------------------------------------------------------------------------------------------------
                                                                   Light heavy-    Medium heavy-   Heavy heavy-
              Model year                        Standard            duty diesel     duty diesel     duty diesel
----------------------------------------------------------------------------------------------------------------
2014-2016.............................  CO2 Standard (g/bhp-hr).             600             600             567
                                        Voluntary Fuel                      5.89            5.89            5.57
                                         Consumption Standard
                                         (gallon/100 bhp-hr).
2017 and Later........................  CO2 Standard (g/bhp-hr).             576             576             555
                                        Fuel Consumption (gallon/           5.66            5.66            5.45
                                         100 bhp-hr).
----------------------------------------------------------------------------------------------------------------

    The agencies explained in the NPRM that the standards were based on 
our assessment of the findings of the 2010 NAS report and other 
literature sources that there are technologies available to reduce fuel 
consumption in all these engines by this level in the final time frame 
in a cost-effective manner. Similar to the technology basis for HD 
engines used in combination tractors, these technologies include 
improved turbochargers, aftertreatment optimization, low temperature 
exhaust gas recirculation, and engine friction reductions.
    The agencies proposed that the HD diesel engine CO2 
standards for vocational vehicles would become effective in MY 2014 for 
EPA, with more stringent CO2 standards becoming effective in 
MY 2017, while NHTSA's fuel consumption standards would become 
effective in MY 2017, which would be both consistent with the EISA 
four-year minimum lead-time requirements and harmonized with EPA's 
timing for stringency increases. The agencies explained that the three-
year timing, besides being required by EISA, made sense because EPA's 
heavy-duty highway engine program for criteria pollutants had begun to 
provide new emissions standards for the industry in three year 
increments, which had caused the heavy-duty engine and vehicle 
manufacturer product plans to fall largely into three year cycles 
reflecting this regulatory environment.\141\ To further harmonize with 
EPA, NHTSA proposed voluntary fuel consumption standards for HD diesel 
engines for vocational vehicles in MYs 2014-2016, allowing 
manufacturers to opt into the voluntary standards in any of those model 
years.\142\ Manufacturers opting into the program must declare by 
statement their intent to comply prior to or at the same time they 
submit their first application for a certificate of conformity. A 
manufacturer opting into the program would begin tracking credits and 
debits beginning in the model year in which they opt in. Both agencies 
proposed to allow manufacturers to generate and use credits to achieve 
compliance with the HD diesel engine standards for vocational vehicles, 
including averaging, banking, and trading (ABT), and deficit carry-
forward.
---------------------------------------------------------------------------

    \141\ See generally 75 FR at 74200-201.
    \142\ Once a manufacturer opts into the NHTSA program it must 
stay in the program for all the optional MYs and remain standardized 
with the implementation approach being used to meet the EPA emission 
program.
---------------------------------------------------------------------------

    The agencies proposed to require HD diesel engine manufacturers to 
achieve, on average, a three percent reduction in fuel consumption and 
CO2 emissions for the 2014 standards over the baseline MY 
2010 performance for the HHD diesel engines, and a five percent 
reduction for the LHD and MHD diesel engines. The standards for the LHD 
and MHD engine categories were proposed to be set at the same level 
because the agencies found that there is an overlap in the displacement 
of engines which are currently certified as LHDD or MHDD. The agencies 
developed the baseline 2010 model year CO2 emissions from 
data provided to EPA by manufacturers during the non-GHG certification 
process. Analysis of CO2 emissions from 2010 model year LHD 
and MHDD diesel engines showed little difference between LHD and MHD 
diesel engine baseline CO2 performance in the 2010 model 
year, which overall averaged 630 g CO2/bhp-hr (6.19 gal/100 
bhp-hr).\143\ Furthermore, the technologies available to reduce fuel 
consumption and CO2 emissions from these two categories of 
engines are similar. The agencies considered combining these engine 
categories into a single category, but decided to maintain these two 
separate engine categories with the same standard level to respect the 
different useful life periods associated with each category.
---------------------------------------------------------------------------

    \143\ Calculated using the conversion 10,180 g CO2/
gallon for diesel fuel.
---------------------------------------------------------------------------

    For vocational engines certified on the FTP cycle, the agencies 
proposed to require a five percent reduction for HHD engines and nine 
percent for LHD and MHD engines. For LHD and MHD engines in 2017 MY, 
the nine percent reduction is based on the assumption that valvetrain 
friction reduction can be achieved in LHD and MHD engines in addition 
to turbo efficiency and accessory (water, oil, and fuel pump) 
improvements, improved EGR cooler, and other approaches being used for 
HHD engines.
    Commenters who discussed the HD diesel engine standards generally 
did not differentiate between the standards for engines used in 
combination tractors and the engines used in vocational vehicles. As 
explained above in Section II.B.2.b, some commenters, such as EMA/TMA, 
Cummins, DTNA, and other manufacturers, supported the proposed 
standards, as long as the flexibilities proposed in the NPRM were 
finalized as proposed. Volvo argued that the standards are being phased 
in too quickly. Environmental groups and NGOs commented that the 
standards should be more stringent and reflect the potential for 
greater fuel consumption and CO2 emissions reductions 
through the use of additional technologies outlined in the 2010 NAS 
study.
    In response to those comments, the agencies refer back to our 
discussion in Section II.B.2.b. The agencies believe that the 
additional reductions may be achieved through the increased development 
of the technologies evaluated for the 2014 model year standard, but the 
agencies' analysis indicates that this type of advanced engine 
development will require a longer development time than MY 2014. The 
agencies are therefore providing additional lead time to allow for the 
introduction of this additional technology, and waiting until 2017 to 
increase stringency to levels reflecting application of 
turbocompounding. See Chapter 2 of the RIA for more details.
    While it made sense to set standards at the same level for LHD and 
MHD diesel engines for vocational vehicles, the agencies found that it 
did not make sense to set HHD standards at the same level. Based on 
manufacturer-submitted

[[Page 57178]]

CO2 data for the non-GHG emissions certification process, 
the agencies found that the baseline for HHD diesel engines was much 
lower than for LHD/MHD diesel engines--584 g CO2/bhp-hr 
(5.74 gal/100 bhp-hr) on average for HHD, compared to 630 g 
CO2/bhp-hr (6.19 gal/100 bhp-hr) on average for LHD/
MHD.\144\ In addition to the differences in the baseline performance, 
the agencies believe that there may be some technologies available to 
reduce fuel consumption and CO2 emissions that may be 
appropriate for the HHD diesel engines but not for the LHD/MHD diesel 
engines, such as turbocompounding. Therefore, the agencies are setting 
a different standard level for HHD diesel engines to be used in 
vocational vehicles. Additional discussion on technical feasibility is 
included in Section III below and in Chapter 2 of the RIA.
---------------------------------------------------------------------------

    \144\ Calculated using the conversion 10,180 g CO2/
gallon for diesel fuel.
---------------------------------------------------------------------------

    After consideration of the comments, EPA and NHTSA are adopting as 
proposed the CO2 emission standards and fuel consumption 
standards for heavy-duty diesel engines installed in vocational 
vehicles are presented in Table II-17. Consistent with proposal, the 
first set of standards take effect with MY 2014 (mandatory standards 
for EPA, voluntary standards for NHTSA), and the second set take effect 
with MY 2017 (mandatory for both agencies).
    Compliance with the standards for engines installed in vocational 
vehicles will be evaluated based on the composite HD FTP cycle. In the 
NPRM, the agencies proposed standards based on the Heavy-duty FTP cycle 
for engines used in vocational vehicles reflecting their primary use in 
transient operating conditions (typified by both frequent accelerations 
and decelerations), as well as in some steady cruise conditions as 
represented on the Heavy-duty FTP. The primary reason the agencies 
proposed two separate certification cycles for HD diesel engines--one 
for HD diesel engines used in combination tractors and the other for HD 
diesel engines used in vocational vehicles--is to encourage engine 
manufacturers to install technologies appropriate to the intended use 
of the engine with the vehicle.\145\
---------------------------------------------------------------------------

    \145\ See generally 75 FR at 74201.
---------------------------------------------------------------------------

    DTNA, Cummins, EMA/TMA, and Honeywell commented that certain 
vocational vehicle applications would achieve greater fuel consumption 
and CO2 emissions reductions in-use by using an engine 
designed to meet the SET-based standard. They stated that some 
vocational vehicles operate at steady-state more frequently than in 
transient operation, such as motor coaches, and thus should be able to 
have an engine certified on a steady-state cycle to better reflect the 
vehicle's real use.
    In response, while the agencies recognize the value to 
manufacturers of having additional flexibility that allows them to meet 
the standards in a way most consistent with how their vehicles and 
engines will ultimately be used, we remain concerned about increasing 
flexibility in ways that might impair fuel consumption and 
CO2 emissions reductions. The agencies are therefore 
providing the option in these final rules for some vocational vehicles, 
but not others, to have SET certified engines. Heavy heavy-duty 
vocational engines will be allowed to be SET certified for vocational 
vehicles, since SET certified HHD engines must meet more stringent GHG 
and fuel consumption standards than FTP certified engines. We believe 
this will provide manufacturers additional flexibility while still 
achieving the expected fuel consumption and CO2 emissions 
reductions. However, medium heavy-duty vocational engines will not be 
allowed to be SET-certified, because medium heavy-duty engines 
certified on the FTP must meet a more stringent standard than engines 
certified on the SET, and the agencies are not confident that fuel 
consumption and CO2 emissions reduction levels would 
necessarily be maintained.
    As discussed above in Section II.B.2.b, the agencies place 
important weight in making our decisions about the cost-effectiveness 
of the standards and the availability of lead time on the fact that 
engine manufacturers are expected to redesign and upgrade their 
products during MYs 2014-2017. The final two-step CO2 
emission and fuel consumption standards recognize the opportunity for 
technology improvements over the rulemaking time frame, while 
reflecting the typical diesel truck manufacturers' and diesel engine 
manufacturers' product plan cycles. Over these four model years there 
will be an opportunity for manufacturers to evaluate almost every one 
of their engine models and add technology in a cost-effective way, 
consistent with existing redesign schedules, to control GHG emissions 
and reduce fuel consumption. The time-frame and levels for the 
standards, as well as the ability to average, bank and trade credits 
and carry a deficit forward for a limited time, are expected to provide 
manufacturers the time needed to incorporate technology that will 
achieve the final GHG and fuel consumption reductions, and to do this 
as part of the normal engine redesign process. This is an important 
aspect of the final rules, as it will avoid the much higher costs that 
would occur if manufacturers needed to add or change technology at 
times other than these scheduled redesigns.\146\ This time period will 
also provide manufacturers the opportunity to plan for compliance using 
a multi-year time frame, again in accord with their normal business 
practice. Further details on lead time, redesigns and technical 
feasibility can be found in Section III.
---------------------------------------------------------------------------

    \146\ See 75 FR at 25467-68.
---------------------------------------------------------------------------

    The agencies recognize, however, that the schedule of changes for 
the final standards may not be the most cost-effective one for all 
manufacturers. For HD diesel engines for use in tractors, the agencies 
discussed above in Section II.B.2.b our decision in this final program 
to allow an ``OBD phase-in'' option for meeting the standards, based on 
comments received from several industry organizations indicating that 
aligning technology changes for multiple regulatory requirements would 
provide them with greater flexibility. In the context of HD diesel 
engines for use in vocational vehicles, Volvo, EMA/TMA, and DDC 
specifically requested an ``OBD phase-in'' option in its comments to 
the NPRM. DDC argued that bundling design changes where possible can 
reduce the burden on industry for complying with regulations, so 
aligning the introduction of the OBD, GHG, and fuel consumption 
standards could help reduce the resources devoted to validation of new 
product designs and certification.
    The agencies have the same interest in providing this flexibility 
for manufacturers of HD diesel engines for use in vocational vehicles 
as in providing it for manufacturers of HD diesel engines for use in 
combination tractors, as long as equivalent emissions and fuel savings 
are maintained. Thus, in order to provide additional flexibility for 
manufacturers looking to align their technology changes with multiple 
regulatory requirements, the agencies are finalizing an alternate ``OBD 
phase-in'' option for meeting the HD diesel engine standards which 
delivers equivalent CO2 emissions and fuel consumption 
reductions as the primary standards for the engines built in the 2013 
through 2017 model years, as shown in Table II-18.

[[Page 57179]]



    Table II-18--Comparison of CO2 reductions for the Engine Standards Under the Alternative OBD Phase-in and
                                                Primary Phase-In
----------------------------------------------------------------------------------------------------------------
                                 HHD FTP                                                LHD/MHD FTP
----------------------------------------------------------------------------------------------------------------
                                                               Difference                             Difference
                                      Primary      Optional   in lifetime    Primary      Optional   in lifetime
                                      phase-in     phase-in    CO2 engine    phase-in     phase-in    CO2 engine
                                    standard (g/ standard (g/  emissions   standard (g/ standard (g/  emissions
                                      bhp-hr)      bhp-hr)       (MMT)       bhp-hr)      bhp-hr)       (MMT)
----------------------------------------------------------------------------------------------------------------
Baseline..........................          584          584  ...........          630          630
2013 MY Engine....................          584          577           20          630          618           14
2014 MY Engine....................          567          577          -28          600          618          -22
2015 MY Engine....................          567          577          -28          600          618          -22
2016 MY Engine....................          567          555           34          600          576           29
2017 MY Engine....................          555          555            0          576          576            0
Net Reductions (MMT)..............  ...........  ...........           -3  ...........  ...........            0
----------------------------------------------------------------------------------------------------------------

     Table II-19 presents the final HD diesel engine CO2 
emission and fuel consumption standards under the optional ``OBD phase-
in'' option.

                            Table II-19--Optional Heavy-Duty Engine Standard Phase-in
----------------------------------------------------------------------------------------------------------------
                                                                   Light heavy-    Medium heavy-   Heavy heavy-
              Model year                        Standard            duty diesel     duty diesel     duty diesel
----------------------------------------------------------------------------------------------------------------
2013..................................  CO2 Standard (g/bhp-hr).             618             618             577
                                        Voluntary Fuel                      6.07            6.07            5.67
                                         Consumption Standard
                                         (gallon/100 bhp-hr).
2016 and Later........................  CO2 Standard (g/bhp-hr).             576             576             555
                                        Fuel Consumption (gallon/           5.66            5.66            5.45
                                         100 bhp-hr).
----------------------------------------------------------------------------------------------------------------

    In order to ensure equivalent CO2 and fuel consumption 
reductions and orderly compliance, and to avoid gaming, the agencies 
are requiring that if a manufacturer selects the OBD phase-in option, 
it must certify its engines starting in the 2013 model year and 
continue using this phase-in through the 2016 model year. Manufacturers 
may opt into the OBD phase-in option through the voluntary NHTSA 
program, but must opt in in the 2013 model year and continue using this 
phase-in through the 2016 model year. Manufacturers that opt in to the 
voluntary NHTSA program in 2014 and 2015 will be required to meet the 
primary phase-in schedule and may not adopt the OBD phase-in option.
    As discussed above in Section II.B.2.b, while the agencies believe 
that the HD diesel engine standards are appropriate, cost-effective, 
and technologically feasible in the rulemaking time frame, we also 
recognize that when regulating a category of engines for the first 
time, there will be individual products that may deviate significantly 
from the baseline level of performance, whether because of a specific 
approach to criteria pollution control, or due to engine calibration 
for specific applications or duty cycles. That earlier discussion 
described HD diesel engines for use in combination tractors, but the 
same supporting information is relevant to the agencies' consideration 
of an alternate standard for HD diesel engines installed in vocational 
vehicles. In the NPRM, the agencies proposed an optional engine 
standard for HD diesel engines installed in vocational vehicles based 
on a five percent reduction from the engine's own 2011 model year 
baseline level, but requested comment on whether a two percent 
reduction would be more appropriate.\147\ The comments received in 
response did not directly address engines for vocational vehicles, but 
the agencies believe that the information provided by Navistar and 
others is equally applicable to HD diesel engines for combination 
tractors and for vocational vehicles. Our assessment for the final 
standards is that a 2.5 percent reduction is appropriate for LHD and 
MHD engines installed in vocational vehicles and 3 percent is 
appropriate for HHD engines installed in vocational vehicles given the 
technologies available for application to legacy products by model year 
2014.\148\ Unlike the majority of engine products in this segment, 
engine manufacturers have devoted few resources to developing 
technologies for these legacy products reasoning that the investment 
would have little value if the engines are to be substantially 
redesigned or replaced in the next five years. Hence, although the 
technologies we have identified to achieve the proposed five percent 
reduction would theoretically work for these legacy products, there is 
inadequate lead time for manufacturers to complete the pre-application 
development needed to add the technology to these engines by 2014. The 
mix of technologies available off the shelf for legacy engines varies 
between engine lines within OEMs and varies among OEMs as well. On 
average, based on our review of manufacturer development history and 
current plans, we project that for the legacy products approximately 
half of the defined technologies appropriate for the 2014 standard will 
be available and ready for application by 2014 for older legacy engine 
designs. Hence, we have concluded that if we limit the reductions to 
those improvements which reflect further enhancements of already 
installed systems rather than the addition or replacement of 
technologies with fully developed new on the shelf components, the 
potential improvement for the 2014 model year will be 2.5 percent for 
LHD and MHD engines and 3 percent HHD engines.
---------------------------------------------------------------------------

    \147\ See 75 FR at 74202.
    \148\ To be codified at 40 CFR 1036.620.
---------------------------------------------------------------------------

    Just as for HD diesel engines used in combination tractors, the 
agencies stress that this option for HD engines used in vocational 
vehicles is temporary and

[[Page 57180]]

limited and is being adopted to address diverse manufacturer needs 
associated with complying with this first phase of the regulations. 
This optional, alternative standard will be available only for the 2014 
through 2016 model years, because we believe that manufacturers will 
have had ample opportunity to make appropriate changes to bring their 
product performance into line with the rest of the industry after that 
time. This optional standard will not be available unless and until a 
manufacturer has exhausted all available credits and credit 
opportunities, and engines under the alternative standard could not 
generate credits.
    The agencies note that manufacturers choosing to utilize this 
option in MYs 2014-2016 will have to make a greater relative 
improvement in MY 2017 than the rest of the industry, since they will 
be starting from a worse level. For compliance purposes, in MYs 2014-
2016 emissions from engines certified and sold at the alternate level 
will be averaged with emissions from engines certified and sold at more 
stringent levels to arrive at a weighted average emissions level for 
all engines in the subcategory. Again, this option can only be taken if 
all other credit opportunities have been exhausted and the manufacturer 
still cannot meet the primary standards. If a manufacturer chooses this 
option to meet the EPA emission standards in MY 2014-2016, and wants to 
opt into the NHTSA fuel consumption program in these same MYs it must 
follow the exact path followed under the EPA program utilizing 
equivalent fuel consumption standards.
    As discussed above in Section II.B.2.b, Volvo argued that 
manufacturers could game the standard by establishing an artificially 
high 2011 baseline emission level. This could be done, for example, by 
certifying an engine with high fuel consumption and GHG emissions that 
is either: (1) Not sold in significant quantities; or (2) later altered 
to emit fewer GHGs and consume less fuel through service changes. In 
order to mitigate this possibility, the agencies are requiring either 
that the 2011 model year baseline must be developed by averaging 
emissions over all engines in an engine averaging set certified and 
sold for that model year so as to prevent a manufacturer from 
developing a single high GHG output engine solely for the purpose of 
establishing a high baseline or meet additional criteria. The agencies 
are allowing manufacturers to combine light heavy-duty and medium 
heavy-duty diesel engines into a single averaging set for this 
provision because the engines have the same GHG emissions and fuel 
consumption standards. If a manufacturer does not certify all engine 
families in an averaging set to the alternate standards, then the 
tested configuration of the engine certified to the alternate standard 
must have the same engine displacement and its rated power within 5 
percent of the highest rated power as the baseline engine. In addition, 
the tested configurations must have a BSFC equivalent to or better than 
all other configurations within the engine family and represent a 
configuration that is sold to customers.
(ii) Gasoline Engine Standard
    Heavy-duty gasoline engines are also used in vocational vehicle 
applications. The number of engines certified in the past for this 
segment of vehicles is very limited and has ranged between three and 
five engine models.\149\ Unlike the heavy-duty diesel engines typical 
of this segment which are built for vocational vehicles, these gasoline 
engines are developed for heavy-duty pickup trucks and vans primarily, 
but are also sold as loose engines to vocational vehicle manufacturers, 
for use in vocational vehicles such as some delivery trucks. Some 
fleets still prefer gasoline engines over diesel engines. In the past, 
this was the case since gasoline stations were more prevalent than 
stations that sold diesel fuel. Because they are developed for HD 
pickups and vans, the agencies evaluated these engines in parallel with 
the heavy-duty pickup truck and van standard development. As in the 
pickup truck and van segment, the agencies anticipated that the 
manufacturers will have only one engine re-design within the 2014-2018 
model years under consideration within the proposal. The agencies 
therefore proposed fuel consumption and CO2 emissions 
standards for gasoline engines for use in vocational vehicles, which 
represent a five percent reduction in CO2 emissions and fuel 
consumption in the 2016 model year over the 2010 MY baseline through 
use of technologies such as coupled cam phasing, engine friction 
reduction, and stoichiometric gasoline direct injection.
---------------------------------------------------------------------------

    \149\ EPA's heavy-duty engine certification database at http://www.epa.gov/otaq/certdata.htm#largeng.
---------------------------------------------------------------------------

    In our meetings with all three of the major manufacturers in the HD 
pickup and van segment, confidential future product plans were shared 
with the agencies. Reflecting those plans and our estimates for when 
engine changes will be made in alignment with those product plans, we 
had concluded for proposal that the 2016 model year reflects the most 
logical model year start date for the heavy-duty gasoline engine 
standards. In order to meet the standards we are finalizing for heavy-
duty pickups and vans, we project that all manufacturers will have 
redesigned their gasoline engine offerings by the start of the 2016 
model year. Given the small volume of loose gasoline engine sales 
relative to complete heavy-duty pickup sales, we think it is 
appropriate to set the timing for the heavy-duty gasoline engine 
standard in line with our projections for engine redesigns to meet the 
heavy-duty pickup truck standards. Therefore, NHTSA's final fuel 
consumption standard and EPA's final CO2 standard for heavy-
duty gasoline engines are first effective in the 2016 model year.
    The baseline 2010 model year CO2 performance of these 
heavy-duty gasoline engines over the Heavy-duty FTP cycle is 660 g 
CO2/bhp-hr (7.43 gal/100 bhp-hr) in 2010 based on non-GHG 
certification data provided to EPA by the manufacturers. The agencies 
are finalizing 2016 model year standards that require manufacturers to 
achieve a five percent reduction in CO2 compared to the 2010 
MY baseline through use of technologies such as coupled cam phasing, 
engine friction reduction, and stoichiometric gasoline direct 
injection. Additional detail on technology feasibility is included in 
Section III and in the RIA Chapter 2. As shown in Table II-20, NHTSA is 
finalizing as proposed a 7.06 gallon/100 bhp-hr standard for fuel 
consumption while EPA is adopting as proposed a 627 g CO2/
bhp-hr standard tested over the Heavy-duty FTP, effective in the 2016 
model year. Similar to EPA's non-GHG standards approach, manufacturers 
may generate and use credits by the same engine averaging set to show 
compliance with both agencies' standards.

            Table II-20--Heavy-Duty Gasoline Engine Standards
------------------------------------------------------------------------
                                                             Gasoline
            Model year                                        engine
                                                             standard
------------------------------------------------------------------------
2016 and Later....................  CO2 Standard (g/bhp-             627
                                     hr).
                                    Fuel Consumption                7.06
                                     (gallon/100 bhp-hr).
------------------------------------------------------------------------

(c) In-Use Standards
    Section 202(a)(1) of the CAA specifies that emissions standards are 
to be applicable for the useful life of the vehicle. The in-use 
standards that EPA

[[Page 57181]]

is finalizing apply to individual vehicles and engines. NHTSA is not 
finalizing in-use standards that would apply to the vehicles and 
engines in a similar fashion.
    EPA proposed that the in-use standards for heavy-duty engines 
installed in vocational vehicles be established by adding an adjustment 
factor to the full useful life emissions results projected in the EPA 
certification process to account for measurement variability inherent 
in testing done at different laboratories with different engines. The 
agency proposed a two percent adjustment factor and requested comments 
and additional data during the proposal to assist in developing an 
appropriate factor level. The agency received additional data during 
the comment period which identified production variability which was 
not accounted for at proposal. Details on the development of the final 
adjustment factor are included in RIA Chapter 3. Based on the data 
received, EPA determined that the adjustment factor in the final rules 
should be higher than the proposed level of two percent. EPA is 
finalizing a three percent adjustment factor for the in-use standard to 
provide a reasonable margin for production and test-to-test variability 
that could result in differences between the initial emission test 
results and emission results obtained during subsequent in-use testing.
    We are finalizing regulatory text (in Sec.  1036.150) to allow 
engine manufacturers to used assigned deterioration factors (DFs) 
without performing their own durability emission tests or engineering 
analysis. However, the engines would still be required to meet the 
standards in actual use without regard to whether the manufacturer used 
the assigned DFs. This allowance is being adopted as an interim 
provision applicable only for this initial phase of standards.
    Manufacturers will be allowed to use an assigned additive DF of 0.0 
g/bhp-hr for CO2 emissions from any conventional engine 
(i.e., an engine not including advance or innovative technologies). 
Upon request, we could allow the assigned DF for CO2 
emissions from engines including advance or innovative technologies, 
but only if we determine that it would be consistent with good 
engineering judgment. We believe that we have enough information about 
in-use CO2 emissions from conventional engines to conclude 
that they will not increase as the engines age. However, we lack such 
information about the more advanced technologies.
    EPA proposed that the useful life for these engines and vehicles 
with respect to GHG emissions be set equal to the respective useful 
life periods for criteria pollutants. EPA proposed that the existing 
engine useful life periods, as included in Table II-21, be broadened to 
include CO2 emissions and fuel consumption for both engines 
and vocational vehicles. The agency did not receive any adverse 
comments with this approach and is finalizing the useful life periods 
as proposed (see 40 CFR 1036.108(d) and 1037.105). While NHTSA will use 
useful life considerations for establishing fuel consumption 
performance for initial compliance and for ABT, NHTSA does not intend 
to implement an in-use compliance program for fuel consumption, because 
it is not required under EISA and because it is not currently 
anticipated there will be notable deterioration of fuel consumption 
over the engines' useful life.

                    Table II-21--Useful Life Periods
------------------------------------------------------------------------
                                               Years           Miles
------------------------------------------------------------------------
Class 2b-5 Vocational Vehicles, Spark                 10         110,000
 Ignited, and Light Heavy-Duty Diesel
 Engines................................
Class 6-7 Vocational Vehicles and Medium              10         185,000
 Heavy-Duty Diesel Engines..............
Class 8 Vocational Vehicles and Heavy                 10         435,000
 Heavy-Duty Diesel Engines..............
------------------------------------------------------------------------

(2) Test Procedures and Related Issues
    The agencies are finalizing test procedures to evaluate fuel 
consumption and CO2 emissions of vocational vehicles in a 
manner very similar to Class 7 and Class 8 combination tractors. This 
section describes the simulation model for demonstrating compliance, 
engine test procedures, and a test procedure for evaluating hybrid 
powertrains (a potential means of generating credits, although not part 
of the technology package on which the final standard for vocational 
vehicles is premised).
(a) Computer Simulation Model
    As previously mentioned, to achieve the goal of reducing emissions 
and fuel consumption for both trucks and engines, we are finalizing 
separate engine and vehicle-based emission and fuel consumption 
standards for vocational vehicles and engines used in those vehicles. 
For the vocational vehicles, engine manufacturers are subject to the 
engine standards, and chassis manufacturers are required to install 
certified engines in their chassis. The chassis manufacturer is subject 
to a separate vehicle-based standard that uses the final vehicle 
simulation model, the GEM, to evaluate the impact of the tire design to 
determine compliance with the vehicle standard.
    A simulation model, in general, uses various inputs to characterize 
a vehicle's properties (such as weight, aerodynamics, and rolling 
resistance) and predicts how the vehicle would behave on the road when 
it follows a driving cycle (vehicle speed versus time). On a second-by-
second basis, the model determines how much engine power needs to be 
generated for the vehicle to follow the driving cycle as closely as 
possible. The engine power is then transmitted to the wheels through 
transmission, driveline, and axles to move the vehicle according to the 
driving cycle. The second-by-second fuel consumption of the vehicle, 
which corresponds to the engine power demand to move the vehicle, is 
then calculated according to the fuel consumption map embedded in the 
compliance model. Similar to a chassis dynamometer test, the second-by-
second fuel consumption is aggregated over the complete drive cycle to 
determine the fuel consumption of the vehicle.
    NHTSA and EPA are finalizing an approach consistent with the 
proposal to evaluate fuel consumption and CO2 emissions 
respectively through a simulation of whole-vehicle operation, 
consistent with the NAS recommendation to use a truck model to evaluate 
truck performance. The EPA developed the GEM for the specific purpose 
of this rulemaking to evaluate vehicle performance. The GEM is similar 
in concept to a number of vehicle simulation tools developed by 
commercial and government entities. The model developed by the EPA and 
finalized here was designed for the express purpose of vehicle 
compliance demonstration and is therefore simpler and less configurable 
than similar

[[Page 57182]]

commercial products. This approach gives a compact and quicker tool for 
evaluating vehicle compliance without the overhead and costs of a more 
complicated model. Details of the model, including changes made to the 
model to address concerns of the peer reviewers and commenters are 
included in Chapter 4 of the RIA. An example of the GEM input screen is 
shown in Figure II-4.
[GRAPHIC] [TIFF OMITTED] TR15SE11.004

    EPA and NHTSA have validated the GEM simulation of vocational 
vehicles against a commonly used simulation tool used in industry, GT-
Drive, for each vocational vehicle subcategory. Prior to using GT-Drive 
as a comparison tool, the agencies first benchmarked a GT-Drive 
simulation of the combination tractor tested at Southwest Research 
against the experimental test results from the chassis dynamometer in 
the same manner as done for GEM. Then the EPA developed three 
vocational vehicle models (LHD, MHD, and HHD) and simulated them using 
both GEM and GT-Drive. Overall, the GEM and GT-Drive predicted the fuel 
consumption and CO2 emissions for all three vocational 
vehicle subcategories with differences of less than 2 percent for the 
three test cycles--the California ARB Transient cycle, 55 mph cruise, 
and 65 mph cruise cycle.\150\ The final simulation model is described 
in greater detail in RIA Chapter 4 and is available for download by 
interested parties at (http://www.epa.gov/otaq/).
---------------------------------------------------------------------------

    \150\ See RIA Chapter 4, Table 4-8.
---------------------------------------------------------------------------

    The agencies are requiring that for demonstrating compliance, a 
chassis manufacturer would measure the performance of tires, input the 
values into GEM, and compare the model's output to the standard. As 
explained earlier, low rolling resistance tires are the only technology 
on which the agencies' own feasibility analysis for these vehicles is 
predicated. The input values for the simulation model will be derived 
by the manufacturer from the final tire test procedure described in 
this action. The remaining model inputs will be fixed values pre-
defined by the agencies. These are detailed in the RIA Chapter 4, 
including the engine fuel consumption map to be used in the simulation.
(b) Tire Rolling Resistance Assessment
    In terms of how tire rolling resistance would be measured, the 
agencies proposed to require that the tire rolling resistance input to 
the GEM be determined using ISO 28580:2009(E), Passenger car, truck and 
bus tyres--Methods of measuring rolling resistance--Single point test 
and correlation of measurement results.\151\ The agencies stated that 
they believed the ISO test method was the most appropriate for this 
program because the method is the same one used by the NHTSA tire fuel 
efficiency consumer information program,\152\ by European 
regulations,\153\ and by the EPA SmartWay program.
---------------------------------------------------------------------------

    \151\ See http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=44770.
    \152\ 75 FR 15893, March 30,2010.
    \153\ See http://www.energy.ca.gov/2009publications/CEC-600-2009-010/CEC-600-2009-010-SD-REV.PDF (last accessed May 9, 2011).
---------------------------------------------------------------------------

    The NPRM also discussed the potential for tire-to-tire variability 
to confound rolling resistance measurement results for LRR tires--that 
is, different tires of the same tire model could turn out to have 
different rolling resistance measurements when run on

[[Page 57183]]

the same test. NHTSA's research during the development of the light-
duty vehicle tire fuel efficiency consumer information program 
identified several sources of variability including test procedures, 
test equipment and the tires themselves, but found that all of the 
existing test methods had similar levels of and sources of 
variability.\154\ The agencies proposed to address production tire-to-
tire variability by specifying that three tire samples within each tire 
model be tested three times each, and that the average of the nine 
tests would be used as the Rolling Resistance Coefficient (CRR) for the 
tire, which would be the basis for the rolling resistance value for 
that tire that the manufacturer would enter into the GEM. The agencies 
requested comment on this proposed method.\155\
---------------------------------------------------------------------------

    \154\ 75 FR 15893, March 30, 2010.
    \155\ See generally 75 FR at 74204.
---------------------------------------------------------------------------

    The agencies received many comments on the subject of tire rolling 
resistance, including suggestions for alternative test procedures and 
compliance issues. Regarding whether the agencies should base tire CRR 
inputs for the GEM on the use of the ISO 28580 test procedure, the 
American Automotive Policy Council (AAPC) argued that the agencies 
should instead require the SAE J2452 Coastdown test method for 
calculating tire rolling resistance, which the commenter stated was 
preferred by OEMs because it simulates the use of tires on actual 
vehicles rather than the ISO procedure which tests the tire by itself. 
The Rubber Manufacturers Association (RMA) argued, in contrast, that 
the agencies should use the SAE J1269 multi-point test, which is 
currently the basis for the EPA SmartWay\TM\ CRR baseline values. RMA 
also argued that the SAE J1269 multi-point test can be used to 
accurately predict truck/bus tire CRR at various loads and inflations, 
including at the ISO 28580 load and inflation conditions, and that 
therefore the agencies should use the SAE test, or if the agencies want 
to use ISO, they should accept results from the SAE test and just 
correlate them. Regarding compliance obligations, RMA further argued 
that it was not clear how or in what format testing information would 
need to be provided in order to be in compliance with the proposed 
requirement at Sec.  1037.125(i).
    The agencies analyzed many comments on the subject of tire rolling 
resistance. One of the primary concerns raised in comments was that the 
proposed test protocol and measurement methodology would not adequately 
address production tire variability and measurement variability. 
Commenters stated that machine-to-machine differences are a significant 
source of variation, and this variation would make it difficult for 
manufacturers to be confident that the agency would assign the same CRR 
to a tire was tested for compliance purposes. Commenters argued that 
the ISO 28580 test method is unique in that it specifies a procedure to 
correlate results between different test equipment (i.e., different 
rolling resistance test machines), but not all aspects of the ISO 
procedure have been completely defined. Commenters stated that under 
ISO 28580, the lab alignment procedure depends on the specification of 
a reference test machine to which all other labs will align their 
measurement results. RMA particularly emphasized the need for 
establishing a tire testing reference lab for use with ISO 28580, 
referencing the European Tyre and Rim Technical Organization (ETRTO) 
estimate that CRR values could vary as much as 20 percent absent an 
inter-laboratory alignment procedure. RMA stated the agencies should 
specify a reference laboratory with the designation proposed in a 
supplemental notice that provides public comment. In addition, RMA 
commented that the extra burden proposed by the agencies for testing 
three tires, three times each is nine times more burdensome than what 
is required through the ISO procedure.
    Based on the additional tire rolling resistance research conducted 
by the agencies, we have decided to use the ISO 28580 test procedure, 
as proposed, to measure tire performance for these final rules.
    The agencies believe this test procedure provides two advantages 
over other test methods. First, the ISO 28580 test method is unique in 
that it specifies a procedure to correlate results between different 
test equipment (i.e., different tire rolling resistance test machines). 
This is important because NHTSA's research conducted for the light-duty 
tire fuel efficiency program indicated that machine-to-machine 
differences are a source of variation.\156\ In addition, the ISO 28580 
test procedure is either used, or proposed to be used, by several 
groups including the European Union through Regulation (EC) No 661/2009 
\157\and the California Air Resources Board (CARB) through a staff 
recommendation for a California regulation,\158\ and the EPA SmartWay 
program. Using the ISO 28580 may help reduce burden on manufacturers by 
allowing a single test protocol to be used for multiple regulations and 
programs. While we recognize that commenters recommended the use of 
other test procedures, like SAE J1269, the agencies have determined 
there is no established data conversion method from the SAE J1269 
vehicle condition for vocational vehicle tires to the ISO 28580 single 
point condition at this time, and that given our reasonable preference 
for the ISO procedure, it would not be practical to attempt to include 
the use of the SAE J1269 procedure as an optional way of determining 
CRR values for the GEM inputs.
---------------------------------------------------------------------------

    \156\ 75 FR 15893, March 30, 2010.
    \157\ See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2009:200:0001:0024:EN:PDF (last accessed May 
8, 2011).
    \158\ See http://www.energy.ca.gov/2009publications/CEC-600-2009-010/CEC-600-2009-010-SD-REV.PDF (last accessed May 9, 2011).
---------------------------------------------------------------------------

    The agencies received comments from the Rubber Manufacturers 
Association, Michelin, and Bridgestone which identified the need to 
develop a reference lab and alignment tires. Because the ISO has not 
yet specified a reference lab and machine for the ISO 28580 test 
procedure, NHTSA announced in its March 2010 final rule concerning the 
light-duty tire fuel efficiency consumer information program that NHTSA 
would specify this laboratory for the purposes of implementing that 
rule so that tire manufacturers would know the identity of the machine 
against which they may correlate their test results. NHTSA has not yet 
announced the reference test machine(s) for the tire fuel efficiency 
consumer information program. Therefore, for the light-duty tire fuel 
efficiency rule, the agencies are postponing the specification of a 
procedure for machine-to-machine alignment until a tire reference lab 
is established. The agencies anticipate establishing this lab in the 
future with intentions for the lab to accommodate the light-duty tire 
fuel efficiency program.
    Under the ISO 28580 lab alignment procedure, machine alignment is 
conducted using batches of alignment tires of two models with defined 
differences in rolling resistance that are certified on a reference 
test machine. ISO 28580 specifies requirements for these alignment 
tires (``Lab Alignment Tires'' or LATs), but exact tire sizes or models 
of LATs are not specifically identified in ISO 28580. Because the test 
procedure has not been finalized and heavy-duty LATs are not currently 
defined, the agencies are postponing the use of these elements of ISO 
28580 to

[[Page 57184]]

a future rulemaking. The agencies also note the lab-to-lab comparison 
conducted in the most recent EPA tire test program mentioned 
previously. The agencies reviewed the CRR data from the tires that were 
tested at both the STL and Smithers laboratories to assess inter-
laboratory and machine variability. The agencies conducted statistical 
analysis of the data to gain better understanding of lab-to-lab 
correlation and developed an adjustment factor for data measured at 
each of the test labs. Based on these results, the agencies believe the 
lab-to-lab variation for the STL and Smithers laboratories would have 
very small effect on measured CRR values. Based on the test data, the 
agencies judge that it is reasonable to implement the HD program with 
current levels of variability, and to allow the use of either Smithers 
or STL laboratories for determining the CRR value in the HD program, or 
demonstrate that the test facilities will not bias results low relative 
to Smithers or STL laboratories.
    RMA also commented that the extra burden proposed by the agencies 
for testing three tires, three times each is nine times more burdensome 
than what is required through the ISO procedure. Since the proposal, 
EPA obtained replicate test data for a number of Class 8 combination 
tractor tires from various manufacturers. Some of these were tires 
submitted to SmartWay for verification, while some were tires tested by 
manufacturers for other purposes. Three tire model samples for 11 tire 
models were tested using the ISO 28580 test.\159\ A mean and a standard 
deviation were calculated for each set of three replicate measurements 
performed on each tire of the 3-tire sample. The coefficient of 
variability (COV) of the CRR was calculated by dividing the standard 
deviation by the mean. The values of COV ranged from 0 percent (no 
measurable variability) to six percent. In addition, during the period 
September 2010 and June 2011, EPA contracted with Smithers-Rapra to 
select and test for rolling resistance using ISO 28580 for a 
representative sample of Class 4-8 vocational vehicle tires. As part of 
the test, 10 tires were selected for replicate testing.\160\ Three 
replicate tests were conducted for each of the tires, to evaluate test 
variability only. The COV of the RRC results ranged from 
nearly 0 to 2 percent, with a mean of less than 1 percent. Based on the 
results of these two testing programs, the agencies determined that the 
impact of production variability is greater than the impact of 
measurement variability. Thus, the agencies concluded that the extra 
burden of testing a single tire three times was not necessary to obtain 
accurate results, but the variability of RRC results due to 
manufacturing of the tires is significant to continue to require 
testing of three tire samples for each tire model. In summary, we are 
allowing manufacturers to determine the rolling resistance coefficient 
of the heavy-duty tires by testing three tire samples one time each.
---------------------------------------------------------------------------

    \159\ Bachman, Joseph. EPA Memorandum to the Docket. Heavy-Duty 
Tire Evaluation. Docket EPA-HQ-OAR-2010-0162. July 2011.
    \160\ Bachman, Joseph. EPA Memorandum to the Docket. Heavy-Duty 
Tire Evaluation. Docket EPA-HQ-OAR-2010-0162. July 2011.
---------------------------------------------------------------------------

    For the final rules, the agencies are also including a warm up 
cycle as part of the procedure for bias ply tires to allow these tires 
to reach a steady temperature and volume state before ISO 28580 
testing. This procedure is similar to a procedure that was developed 
for the light-duty tire fuel efficiency consumer information program, 
and was adopted from a procedure defined in Federal motor vehicle 
safety standard No. 109 (FMVSS No. 109).\161\
---------------------------------------------------------------------------

    \161\ See 49 CFR 571.109.
---------------------------------------------------------------------------

    Finally, the agencies are including testing and reporting for 
`single-wide' or `super-single' type tires. These tires replace the 
traditional `dual' wheel tire combination with a single wheel and tire 
that is nearly as wide as the dual combination with similar load 
capabilities. These tire types were developed as a fuel saving 
technology. The tires provide lower rolling resistance along with a 
reduction in weight when compared to a typical set of dual wheel tire 
combinations; and are one of the technologies included in the EPA 
SmartWay\TM\ program. The agencies have learned that there is limited 
testing equipment available that is capable of testing single wide 
tires; single wide tires require a wider test machine drum than 
required for conventional tires. Although the number of machines 
available is limited, the agencies believe the equipment is adequate 
for the testing and reporting of CRR for this program.
    As discussed above, the agencies are taking the approach of using 
CRR for the HD fuel efficiency and greenhouse gas program to align with 
the measurement methodology already employed or proposed by the EPA 
SmartWay program, the European Union Regulation (EC) No 661/2009 \162\ 
and the California Air Resources Board (CARB) through a staff 
recommendation for a California regulation.\163\ In the NPRM, the 
agencies proposed to use CRR, but for purposes of developing these 
final rules, the agencies also evaluated whether to use CRR or Rolling 
Resistance Force (RRF) as the measurement for tire rolling 
resistance for the GEM input. The agencies considered RRF 
largely because in the NPRM for Passenger Car Tire Fuel Efficiency 
(TFE) program, NHTSA had proposed to use RRF. A key 
distinction between these two programs, and their associated metrics, 
are the differences in how the measurement data are used and who uses 
the data. In particular, the HD fuel efficiency and GHG emissions 
program is a compliance program using information developed by and for 
technical personnel at manufacturers and agencies to determine a 
vehicle's compliance with regulations. The TFE program, in contrast, is 
a consumer education program intended to inform consumers making 
purchase decisions regarding the fuel saving benefits of replacement 
passenger car tires. The target audiences are much different for the 
two programs which in turn affect how the information will be used. The 
agencies believe that RRF may be more intuitive for non-
technical people because tires that are larger and/or that carry higher 
loads will generally have numerically higher RRF values than 
smaller tires and/or tires that carry lower loads. CRR values generally 
follow an opposite trend, where tires that are larger and/or carry 
higher loads will generally have numerically lower CRR values than 
smaller tires and/or tires that carry lower loads. The agencies believe 
this key distinction helps define the type of metrics to be used and 
communicated in accordance with their respective purposes.
---------------------------------------------------------------------------

    \162\ See Note 157, above.
    \163\ See Note 158, above.
---------------------------------------------------------------------------

    Additionally, the CRR metric for use in the MD/HD program is not 
susceptible to the skew associated with tire diameter. Medium- and 
heavy-duty vehicle tires are available in a small fraction of the tire 
sizes of the passenger market and, for the most part, are larger tires 
than those found on passenger cars. When viewing CRR over a larger 
range of sizes, small diameter tires tend to appear as having a lower 
performance, which is not necessarily accurate, with the converse 
occurring as the diameter increases.
    Using the CRR value for determining the rolling resistance also 
takes into account the load carrying capability for the tire being 
tested, which, intuitively, can lead to some potentially confusing 
results. Several vocational vehicle manufacturers argued in their 
comments that LRR tires were not available for, e.g., vehicles like 
refuse trucks, which tend to use large diameter tires to carry very 
heavy loads. Based on the agencies'

[[Page 57185]]

testing, in fact, the measured CRR (as opposed to the RRF) 
for refuse trucks were found to be among the best tested. This finding 
can be explained by considering that CRR is calculated by dividing the 
measured rolling resistance force by the tire's load capacity rating. 
Although the tire may have a relatively high rolling resistance force, 
the tire load capacity rating is also very high, resulting in an 
overall lower (better) CRR value than many other types of tires. The 
amount of load tire can carry (test load) contributes to a very low 
reported CRR, thus confirming low rolling resistance tires meeting the 
standards, as measured by CRR, are available to the industry regardless 
of segment or application.
    Based on these considerations, the agencies have decided to use the 
CRR metric for the HD fuel efficiency and GHG emissions program.
(c) Defined Vehicle Configurations in the GEM
    As discussed above, the agencies are finalizing a methodology that 
chassis manufacturers will use to quantify the tire rolling resistance 
values to be input into the GEM. Moreover, the agencies are defining 
the remaining GEM inputs (i.e., specifying them by rule), which differ 
by the regulatory subcategory (for reasons described in the RIA Chapter 
4). The defined inputs, among others, include the drive cycle, 
aerodynamics, vehicle curb weight, payload, engine characteristics, and 
drivetrain for each vehicle type.
(i) Metric
    Based on NAS's recommendation and feedback from the heavy-duty 
truck industry, NHTSA and EPA proposed standards for vocational 
vehicles that would be expressed in terms of moving a ton of payload 
over one mile. Thus, NHTSA's proposed fuel consumption standards for 
these vehicles would be represented as gallons of fuel used to move one 
ton of payload one thousand miles, or gal/1,000 ton-mile. EPA's 
proposed CO2 vehicle standards would be represented as grams 
of CO2 per ton-mile. The agencies received comments that a 
payload-based metric is not appropriate for all types of vocational 
vehicles, specifically buses. The agencies recognize that a payload-
based approach may not be the most representative of an individual 
vocational application; however, it best represents the broad 
vocational category. The metric which we proposed treats all vocational 
applications equally and requires the same technologies be applied to 
meet the standard. Thus, the agencies are adopting the proposed metric, 
but will revisit the issue of metrics in any future action, if 
required, depending on the breadth of each standard.
(ii) Drive cycle
    The drive cycles proposed for the vocational vehicles consisted of 
the same three modes used for the Class 7 and 8 combination tractors. 
The proposed cycle included the Transient mode, as defined by 
California ARB in the HHDDT cycle, a constant speed cycle at 65 mph and 
a 55 mph constant speed mode. The agencies proposed different 
weightings for each mode for vocational vehicles than those proposed 
for Class 7 and 8 combination tractors, given the known difference in 
driving patterns between these two categories of vehicles. The same 
reasoning underlies the agencies' use of the Heavy-duty FTP cycle to 
evaluate compliance with the standards for diesel engines used in 
vocational vehicles.
    The variety of vocational vehicle applications makes it challenging 
to establish a single cycle which is representative of all such trucks. 
However, in aggregate, the vocational vehicles typically operate over 
shorter distances and spend less time cruising at highway speeds than 
combination tractors. The agencies evaluated for proposal two sources 
for mode weightings, as detailed in RIA Chapter 3. The agencies 
proposed the mode weightings based on the vehicle speed characteristics 
of single unit trucks used in EPA's MOVES model which were developed 
using Federal Highway Administration data to distribute vehicle miles 
traveled by road type.\164\ The proposed weighted CO2 and 
fuel consumption value consisted of 37 percent of 65 mph Cruise, 21 
percent of 55 mph Cruise, and 42 percent of Transient performance.
---------------------------------------------------------------------------

    \164\ The Environmental Protection Agency. Draft MOVES2009 
Highway Vehicle Population and Activity Data. EPA-420-P-09-001, 
August 2009 http://www.epa.gov/otaq/models/moves/techdocs/420p09001.pdf.
---------------------------------------------------------------------------

    The agencies received comments stating that the proposed drive 
cycles and weightings are not representative of individual vocational 
applications, such as buses and refuse haulers. A number of groups 
commented that the vocational vehicle cycle is not representative of 
real world driving and recommended changes to address that concern. 
Several organizations proposed the addition of new drive cycles to make 
the test more representative.
    Bendix suggested using the Composite International Truck Local and 
Commuter Cycle (CILCC) as the general purpose mixed urban/freeway 
cycles and to use four representative cycles: mixed urban, freeway, 
city bus, refuse, and utility. Bendix suggested using the Standardized 
On-Road Test (SORT) cycles for vocational vehicles operating in the 
urban environment in addition to SORT cycles for 3 different 
vocations--with separate weightings. They stated that SORT with an 
average speed of 11.2 mph, lines up most closely with the average of 
transit bus duty cycles at 9.9 mph as well as the overall U.S. National 
average of 12.6 mph. As alternative approaches they suggested adopting 
the Orange County duty cycle for the urban transit bus vocation, or 
creating an Urban Transit Bus cycle with several possible weighting 
factors--all with very high percentage transient (90% to 100%), very 
low 55 mph (0% to 7%), very low 65 mph (0% to 3%), and an average speed 
of 15 to 17 mph. Bendix supported their assertions about urban bus 
vehicle speed with data from the 2010 American Public Transportation 
Association (APTA) `Fact Book' and other sources. In contrast, Bendix 
stated, the GEM cycle average speed is currently 32.6 mph. Such high 
speeds at steady state will penalize technologies such as 
hybridization.
    Clean Air Task Force said the agencies have not adequately 
addressed the diversity of the vocational vehicle fleet since they are 
not distinguished by different duty cycles. They urged the agencies to 
sub-divide vocational vehicles by expected use, with separate test 
cycles for each sub-group in order to capture the full potential 
benefits of hybridization and other advanced technologies in a 
meaningful and accurate way in future rulemakings for MY2019 and later 
trucks.
    Two groups cautioned that unintended consequences could result from 
the lack of diversity in duty cycles. DTNA said that the single drive 
cycle proposed for all vehicles by the agencies would likely lead to 
unintended consequences--such as customers being driven for regulatory 
reasons to purchase a transmission that does not suit their actual 
operation. Similarly, Volvo said medium- and heavy-duty vehicles are 
uniquely built for specific applications but it will not be feasible to 
develop regulatory protocols that can accurately predict efficiency in 
each application duty cycle. This trade-off could result in unintended 
or negative consequences in parts of the market.
    Several commenters suggested changing the weightings of the cycle 
to more accurately reflect real world driving. Allison stated that the 
vocational vehicle cycle includes too much steady state driving time. 
They suggested (with supporting data from

[[Page 57186]]

the Oakridge National Laboratory analysis) reducing steady state 
driving at 60 mph to minimal or no time on the cycle to address this 
problem. Allison commented that GEM contains lengthy accelerations to 
reach 55 and 65 miles per hour--much longer than is required in real 
world driving. They supported this statement with data from a testing 
program conducted at Oakridge National Laboratory showing medium- and 
heavy-duty vehicles accelerate more rapidly than in the GEM drive 
cycle. According to Allison, this long acceleration time in the GEM, 
coupled with too much steady state operation with very little 
variation, is not representative of vocational vehicle operation. In 
addition, Allison said that the GEM does not adequately account for 
shift time, clutch profile, turbo lag, and other impacts on both steady 
state and transient operation. The impact, they state, is that the 
cycle will hinder proper deployment of technologies to reduce fuel 
consumption and GHG emissions.
    BAE focused their comments on urban transit bus operation. They 
stated the weighting factors for steady state operation are 
inconsistent with urban transit bus cycles.
    Other commenters suggested the agencies develop chassis dynamometer 
tests based on the engine (FTP) test. Cummins said that chassis 
dynamometer testing should allow the use of average vehicle 
characteristics to determine road load and make use of the vehicle FTP 
and SET cycles. Others commented that the correlation between the FTP 
and the UDDS is poor.
    After careful consideration of the comments, the agencies are 
adopting the proposed drive cycles. The final drive cycles and 
weightings represent the straight truck operations which dominate the 
vehicle miles travelled by vocational vehicles. The agencies do not 
believe that application-specific drive cycles are required for this 
final action because the program is based on the generally-applicable 
use of low rolling resistance tires. The drive cycles that we are 
adopting treat all vocational applications equally predicate standard 
stringency on use of the same technology (LRR tires) to meet the 
standard. The drive cycles in the final rule accurately reflect the 
performance of this technology. The agencies are also finalizing, as 
proposed, the mode weightings based on the vehicle speed 
characteristics of single unit trucks used in EPA's MOVES model which 
were developed using Federal Highway Administration data to distribute 
vehicle miles traveled by road type.\165\ Similar to the issue of 
metrics discussed above, the agencies may revisit drive cycles and 
weightings in any future regulatory action to develop standards 
specific to applications.
---------------------------------------------------------------------------

    \165\ The Environmental Protection Agency. Draft MOVES2009 
Highway Vehicle Population and Activity Data. EPA-420-P-09-001, 
August 2009 http://www.epa.gov/otaq/models/moves/techdocs/420p09001.pdf.
---------------------------------------------------------------------------

(iii) Empty Weight and Payload
    The total weight of the vehicle is the sum of the tractor curb 
weight and the payload. The agencies are proposed to specify each of 
these aspects of the vehicle. The agencies developed the proposed 
vehicle curb weight inputs based on industry information developed by 
ICF.\166\ The proposed curb weights were 10,300 pounds for the LHD 
trucks, 13,950 pounds for the MHD trucks, and 29,000 pounds for the HHD 
trucks.
---------------------------------------------------------------------------

    \166\ ICF International. ``Investigation of Costs for Strategies 
to Reduce Greenhouse Gas Emissions for Heavy-Duty On-Road 
Vehicles.'' July 2010. Pages 16-20. Docket ID EPA-HQ-OAR-
2010-0162-0044.
---------------------------------------------------------------------------

    NHTSA and EPA proposed payload requirements for each regulatory 
category developed from Federal Highway statistics based on averaging 
the payloads for the weight categories represented within each vehicle 
subcategory.\167\ The proposed payloads were 5,700 pounds for the Light 
Heavy-Duty trucks, 11,200 pounds for Medium Heavy-Duty trucks, and 
38,000 pounds for Heavy Heavy-Duty trucks.
---------------------------------------------------------------------------

    \167\ The U.S. Federal Highway Administration. Development of 
Truck Payload Equivalent Factor. Table 11. Last viewed on March 9, 
2010 at http://ops.fhwa.dot.gov/freight/freight_analysis/faf/faf2_reports/reports9/s510_11_12_tables.htm.
---------------------------------------------------------------------------

    The agencies received comments from several stakeholders regarding 
the proposed curb weights and payloads for vocational vehicles. BAE 
said a Class 8 transit bus has a typical curb weight of 27,000 pounds 
and maximum payload of 15,000 pounds. Daimler commented that Class 8 
buses have a GVWR of 42,000 pounds. Autocar said that Class 8 refuse 
trucks typically have a curb weight of 31,000 to 33,000 pounds, typical 
average payload of 10,000 pounds, and typical maximum payload of 20,000 
pounds.
    Upon further consideration, the agencies are reducing the assigned 
weight of heavy heavy-duty vocational vehicles. While we still believe 
the proposed values are appropriate for some vocational vehicles, we 
reduced the total weight to bring it closer to some of the lighter 
vocational vehicles. The agencies are adopting final curb weights of 
10,300 pounds for the LHD trucks, 13,950 pounds for the MHD trucks, and 
27,000 pounds for the HHD trucks. The agencies are also adopting 
payloads of 5,700 pounds for the Light Heavy-Duty trucks, 11,200 pounds 
for Medium Heavy-Duty trucks, and 15,000 pounds for Heavy Heavy-Duty 
trucks. Additional information is available in RIA Chapter 3.
(iv) Engine
    As the agencies are finalizing separate engine and vehicle 
standards, the GEM will be used to assess the compliance of the chassis 
with the vehicle standard. To maintain the separate assessments, the 
agencies are adopting the proposed approach of using fixed values that 
are predefined by the agencies for the engine characteristics used in 
GEM, including the fuel consumption map which provides the fuel 
consumption at hundreds of engine speed and torque points. If the 
agencies did not standardize the fuel map, then a vehicle that uses an 
engine with emissions and fuel consumption better than the standards 
would require fewer vehicle reductions than those being finalized. As 
proposed, the agencies are using diesel engine characteristics in the 
GEM, as most representative of the largest fraction of engines in this 
market. The agencies did not receive any adverse comments to using this 
approach.
    The agencies are finalizing two distinct sets of fuel consumption 
maps for use in GEM. The first fuel consumption map would be used in 
GEM for the 2014 through 2016 model years and represent a diesel engine 
which meets the 2014 model year engine CO2 emissions 
standards. A second fuel consumption map would be used beginning in the 
2017 model year and represents a diesel engine which meets the 2017 
model year CO2 emissions and fuel consumption standards and 
accounts for the increased stringency in the final MY 2017 standard). 
The agencies have modified the 2017 MY heavy heavy-duty diesel fuel map 
used in the GEM for the final rulemaking to address comments received. 
Details regarding this change can be found in RIA Chapter 4.4.4. 
Effectively there is no change in stringency of the vocational vehicle 
standard (not including the engine) between the 2014 MY and 2017 MY 
standards for the full rulemaking period. These inputs are reasonable 
(indeed, seemingly necessitated) given the separate final regulatory 
requirement that vocational vehicle chassis manufacturers use only 
certified engines.

[[Page 57187]]

(v) Drivetrain
    The agencies' assessment of the current vehicle configuration 
process at the truck dealer's level is that the truck companies provide 
software tools to specify the proper drivetrain matched to the buyer's 
specific circumstances. These dealer tools allow a significant amount 
of customization for drive cycle and payload to provide the best 
specification for the customer. The agencies are not seeking to disrupt 
this process. Optimal drivetrain selection is dependent on the engine, 
drive cycle (including vehicle speed and road grade), and payload. Each 
combination of engine, drive cycle, and payload has a single optimal 
transmission and final drive ratio. The agencies are specifying the 
engine's fuel consumption map, drive cycle, and payload; therefore, it 
makes sense to specify the drivetrain that matches.
(d) Engine Metrics and Test Procedures
    EPA proposed that the GHG emission standards for heavy-duty engines 
under the CAA would be expressed as g/bhp-hr while NHTSA's proposed 
fuel consumption standards under EISA, in turn, be represented as gal/
100 bhp-hr. The NAS panel did not specifically discuss or recommend a 
metric to evaluate the fuel consumption of heavy-duty engines. However, 
as noted above they did recommend the use of a load-specific fuel 
consumption metric for the evaluation of vehicles.\168\ An analogous 
metric for engines is the amount of fuel consumed per unit of work. The 
g/bhp-hr metric is also consistent with EPA's current standards for 
non-GHG emissions for these engines. The agencies did not receive any 
adverse comments related to the metrics for HD engines; therefore, we 
are adopting the metrics as proposed.
---------------------------------------------------------------------------

    \168\ See NAS Report, Note 21, at page 39.
---------------------------------------------------------------------------

    With regard to GHG and fuel consumption control, the agencies 
believe it is appropriate to set standards based on a single test 
procedure, either the Heavy-duty FTP or SET, depending on the primary 
expected use of the engine. EPA's criteria pollutant standards for 
engines currently require that manufacturers demonstrate compliance 
over the transient Heavy-duty FTP cycle; over the steady-state SET 
procedure; and during not-to-exceed testing. EPA created this multi-
layered approach to criteria emissions control in response to engine 
designs that optimized operation for lowest fuel consumption at the 
expense of very high criteria emissions when operated off the 
regulatory cycle. EPA's use of multiple test procedures for criteria 
pollutants helps to ensure that manufacturers calibrate engine systems 
for compliance under all operating conditions. We are not concerned if 
manufacturers further calibrate these engines off cycle to give better 
in-use fuel consumption while maintaining compliance with the criteria 
emissions standards as such calibration is entirely consistent with the 
goals of our joint program. Further, we believe that setting standards 
based on both transient and steady-state operating conditions for all 
engines could lead to undesirable outcomes.
    It is critical to set standards based on the most representative 
test cycles in order for performance in-use to obtain the intended (and 
feasible) air quality and fuel consumption benefits. We are finalizing 
standards based on the composite Heavy-duty FTP cycle for engines used 
in vocational vehicles reflecting these vehicles' primary use in 
transient operating conditions typified by frequent accelerations and 
decelerations as well as some steady cruise conditions as represented 
on the Heavy-duty FTP. The primary reason the agencies are finalizing 
two separate diesel engine standards--one for diesel engines used in 
tractors and the other for diesel engines used in vocational vehicles--
is to encourage engine manufacturers to install engine technologies 
appropriate to the intended use of the engine with the vehicle. The 
current non-GHG emissions engine test procedures also require the 
development of regeneration emission rates and frequency factors to 
account for the emission changes during a regeneration event (40 CFR 
86.004-28). EPA and NHTSA proposed not to include these emissions from 
the calculation of the compliance levels over the defined test 
procedures. Cummins and Daimler supported and stated sufficient 
incentives already exist for manufacturers to limit regeneration 
frequency. Conversely, Volvo opposed the omission of IRAF requirements 
for CO2 emissions because emissions from regeneration can be 
a significant portion of the expected improvement and a significant 
variable between manufacturers
    For the proposal, we considered including regeneration in the 
estimate of fuel consumption and GHG emissions and decided not to do so 
for two reasons. First, EPA's existing criteria emission regulations 
already provide a strong motivation to engine manufacturers to reduce 
the frequency and duration of infrequent regeneration events. The very 
stringent 2010 NOX emission standards cannot be met by 
engine designs that lead to frequent and extend regeneration events. 
Hence, we believe engine manufacturers are already reducing 
regeneration emissions to the greatest degree possible. In addition to 
believing that regenerations are already controlled to the extent 
technologically possible, we believe that attempting to include 
regeneration emissions in the standard setting could lead to an 
inadvertently lax emissions standard. In order to include regeneration 
and set appropriate standards, EPA and NHTSA would have needed to 
project the regeneration frequency and duration of future engine 
designs in the time frame of this program. Such a projection would be 
inherently difficult to make and quite likely would underestimate the 
progress engine manufacturers will make in reducing infrequent 
regenerations. If we underestimated that progress, we would effectively 
be setting a more lax set of standards than otherwise would be 
expected. Hence in setting a standard including regeneration emissions 
we faced the real possibility that we would achieve less effective 
CO2 emissions control and fuel consumption reductions than 
we will achieve by not including regeneration emissions. Therefore, the 
agencies are finalizing an approach as proposed which does not include 
the regenerative emissions.
(e) Hybrid Powertrain Technology
    Although the final vocational vehicle standards are not premised on 
use of hybrid powertrains, certain vocational vehicle applications may 
be suitable candidates for use of hybrids due to the greater frequency 
of stop-and-go urban operation and their use of power take-off (PTO) 
systems. Examples are vocational vehicles used predominantly in stop-
start urban driving (e.g., delivery trucks). As an incentive, the 
agencies are finalizing to provide credits for the use of hybrid 
powertrain technology as described in Section IV. Under the advanced 
technology credit provisions, credits generated by use of hybrid 
powertrains could be used to meet any of the heavy-duty standards, and 
are not restricted to the averaging set generating the credit, unlike 
the other credit provisions in the final rules. The agencies are 
finalizing that any credits generated using such advanced technologies 
could be applied to any heavy-duty vehicle or engine, and not be 
limited to the averaging set generating the credit. Section IV below 
also details the final approach to account for the use of a hybrid 
powertrain when evaluating compliance with the vehicle standard. In 
general, manufacturers can derive the fuel consumption and 
CO2 emissions

[[Page 57188]]

reductions based on comparative test results using the final chassis 
testing procedures.
(3) Summary of Final Flexibility and Credit Provisions
    EPA and NHTSA are finalizing four flexibility provisions 
specifically for heavy-duty vocational vehicle and engine 
manufacturers, as discussed in Section IV below. These are an 
averaging, banking and trading program for emissions and fuel 
consumption credits, as well as provisions for early credits, advanced 
technology credits, and credits for innovative vehicle or engine 
technologies which are not included as inputs to the GEM or are not 
demonstrated on the engine FTP test cycle. With the exception of the 
advanced technology credits, credits generated under these provisions 
can only be used within the same averaging set which generated the 
credit (for example, credits generated by HHD vocational vehicles can 
only be used by HHD vehicles). EPA is also adopting a temporary 
provision whereby N2O emission credits can be used to comply 
with the CO2 emissions standard, as described in Section IV 
below.
(3) Deferral of Standards for Small Chassis Manufacturing Business and 
Small Business Engine Companies
    EPA and NHTSA are finalizing an approach to defer greenhouse gas 
emissions and fuel consumption standards from small vocational vehicle 
chassis manufacturers meeting the SBA size criteria of a small business 
as described in 13 CFR 121.201 (see 40 CFR 1036.150 and 1037.150). The 
agencies will instead consider appropriate GHG and fuel consumption 
standards for these entities as part of a future regulatory action. 
This includes both U.S.-based and foreign small volume heavy-duty truck 
and engine manufacturers.
    The agencies have identified ten chassis entities that appear to 
fit the SBA size criterion of a small business.\169\ The agencies 
estimate that these small entities comprise less than 0.5 percent of 
the total heavy-duty vocational vehicle market in the United States 
based on Polk Registration Data from 2003 through 2007,\170\ and 
therefore that the exemption will have a negligible impact on the GHG 
emissions and fuel consumption improvements from the final standards.
---------------------------------------------------------------------------

    \169\ The agencies have identified Lodal, Indiana Phoenix, 
Autocar LLC, HME, Giradin, Azure Dynamics, DesignLine International, 
Ebus, Krystal Koach, and Millenium Transit Services LLC as potential 
small business chassis manufacturers.
    \170\ M.J. Bradley. Heavy-duty Vehicle Market Analysis. May 
2009.
---------------------------------------------------------------------------

    EPA and NHTSA have also identified three engine manufacturing 
entities that appear to fit the SBA size criteria of a small business 
based on company information included in Hoover's.\171\ Based on 2008 
and 2009 model year engine certification data submitted to EPA for non-
GHG emissions standards, the agencies estimate that these small 
entities comprise less than 0.1 percent of the total heavy-duty engine 
sales in the United States. The final exemption from the standards 
established under this rulemaking would have a negligible impact on the 
GHG emissions and fuel consumption reductions otherwise due to the 
standards.
---------------------------------------------------------------------------

    \171\ The agencies have identified Baytech Corporation, Clean 
Fuels USA, and BAF Technologies, Inc. as three potential small 
businesses.
---------------------------------------------------------------------------

    To ensure that the agencies are aware of which companies would be 
exempt, we are finalizing as proposed to require that such entities 
submit a declaration to EPA and NHTSA containing a detailed written 
description of how that manufacturer qualifies as a small entity under 
the provisions of 13 CFR 121.201, as described in Section V below.

E. Other Standards

    In addition to finalizing CO2 emission standards for 
heavy-duty vehicles and engines, EPA is also finalizing separate 
standards for N2O and CH4 emissions.\172\ NHTSA 
is not finalizing comparable separate standards for these GHGs because 
they are not directly related to fuel consumption in the same way that 
CO2 is, and NHTSA's authority under EISA exclusively relates 
to fuel efficiency. N2O and CH4 are important 
GHGs that contribute to global warming, more so than CO2 for 
the same amount of emissions due to their high Global Warming Potential 
(GWP).\173\ EPA is finalizing N2O and CH4 
standards which apply to HD pickup trucks and vans as well as to all 
heavy-duty engines. EPA is not finalizing N2O and 
CH4 standards for the Class 7 and 8 tractor or Class 2b-8 
chassis manufacturers because these emissions would be controlled 
through the engine program.
---------------------------------------------------------------------------

    \172\ NHTSA's statutory responsibilities relating to reducing 
fuel consumption are directly related to reducing CO2 
emissions, but not to the control of other GHGs.
    \173\ The global warming potentials (GWP) used in this rule are 
consistent with the 2007 Intergovernmental Panel on Climate Change 
(IPCC) Fourth Assessment Report (AR4). At this time, the 1996 IPCC 
Second Assessment Report (SAR) GWP values are used in the official 
U.S. greenhouse gas inventory submission to the United Nations 
Framework Convention on Climate Change (per the reporting 
requirements under that international convention). N2O 
has a GWP of 298 and CH4 has a GWP of 25 according to the 
2007 IPCC AR4.
---------------------------------------------------------------------------

    EPA requested comment on possible alternative CO2 
equivalent approaches to provide near-term flexibility for 2012-14 MY 
light-duty vehicles. As described below, EPA is finalizing alternative 
provisions allowing manufacturers to use CO2 credits, on a 
CO2-equivalent (CO2eq) basis, to meet the 
N2O and CH4 standards, which is consistent with 
many commenters' preferred approach.
    Almost universally across current engine designs, both gasoline- 
and diesel-fueled, N2O and CH4 emissions are 
relatively low today and EPA does not believe it would be appropriate 
or feasible to require reductions from the levels of current gasoline 
and diesel engines. This is because for the most part, the same 
hardware and controls used by heavy-duty engines and vehicles that have 
been optimized for non-methane hydrocarbon (NMHC) and NOX 
control indirectly result in highly effective control of N2O 
and CH4. Additionally, unlike criteria pollutants, specific 
technologies beyond those presently implemented in heavy-duty vehicles 
to meet existing emission requirements have not surfaced that 
specifically target reductions in N2O or CH4. 
Because of this, reductions in N2O or CH4 beyond 
current levels in most heavy-duty applications would occur through the 
same mechanisms that result in NMHC and NOX reductions and 
would likely result in an increase in the overall stringency of the 
criteria pollutant emission standards. Nevertheless, it is important 
that future engine technologies or fuels not currently researched do 
not result in increases in these emissions, and this is the intent of 
the final ``cap'' standards. The final standards would primarily 
function to cap emissions at today's levels to ensure that 
manufacturers maintain effective N2O and CH4 
emissions controls currently used should they choose a different 
technology path from what is currently used to control NMHC and 
NOX but also largely successful methods for controlling 
N2O and CH4. As discussed below, some 
technologies that manufacturers may adopt for reasons other than 
reducing fuel consumption or GHG emissions could increase 
N2O and CH4 emissions if manufacturers do not 
address these emissions in their overall engine and aftertreatment 
design and development plans. Manufacturers will be able to design and 
develop the engines and aftertreatment to avoid such emissions 
increases through appropriate emission control technology selections 
like those already used and available

[[Page 57189]]

today. Because EPA believes that these standards can be capped at the 
same level, regardless of type of HD engine involved, the following 
discussion relates to all types of HD engines regardless of the 
vehicles in which such engines are ultimately used. In addition, since 
these standards are designed to cap current emissions, EPA is 
finalizing the same standards for all of the model years to which the 
rules apply.
    EPA believes that the final N2O and CH4 cap 
standards will accomplish the primary goal of deterring increases in 
these emissions as engine and aftertreatment technologies evolve 
because manufacturers will continue to target current or lower 
N2O and CH4 levels in order to maintain typical 
compliance margins. While the cap standards are set at levels that are 
higher than current average emission levels, the control technologies 
used today are highly effective and there is no reason to believe that 
emissions will slip to levels close to the cap, particularly 
considering compliance margin targets. The caps will protect against 
significant increases in emissions due to new or poorly implemented 
technologies. However, we also believe that an alternative compliance 
approach that allows manufacturers to convert these emissions to 
CO2eq emission values and combine them with CO2 
into a single compliance value would also be appropriate, so long as it 
did not undermine the stringency of the CO2 standard. As 
described below, EPA is finalizing that such an alternative compliance 
approach be available to manufacturers to provide certain flexibilities 
for different technologies.
    EPA requested comments in the NPRM on the approach to regulating 
N2O and CH4 emissions including the 
appropriateness of ``cap'' standards, the technical bases for the 
levels of the final N2O and CH4 standards, the 
final test procedures, and the final timing for the standards. In 
addition, EPA requested any additional emissions data on N2O 
and CH4 from current technology engines. We solicited 
additional data, and especially data for in-use vehicles and engines 
that would help to better characterize changes in emissions of these 
pollutants throughout their useful lives, for both gasoline and diesel 
applications. As is typical for EPA emissions standards, we are 
finalizing that manufacturers should establish deterioration factors to 
ensure compliance throughout the useful life. We are not at this time 
aware of deterioration mechanisms for N2O and CH4 
that would result in large deterioration factors, but neither do we 
believe enough is known about these mechanisms to justify finalizing 
assigned factors corresponding to no deterioration, as we are 
finalizing for CO2, or for that matter to any predetermined 
level. In addition to N2O and CH4 standards, this 
section also discusses air conditioning-related provisions and EPA 
provisions to extend certification requirements to all-electric HD 
vehicles and vehicles and engines designed to run on ethanol fuel.
(1) What is EPA's Approach to Controlling N2O?
    N2O is a global warming gas with a GWP of 298. It 
accounts for about 0.3 percent of the current greenhouse gas emissions 
from heavy-duty trucks.\174\
---------------------------------------------------------------------------

    \174\ Value adapted from ``Inventory of U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2007''. April 2009.
---------------------------------------------------------------------------

    N2O is emitted from gasoline and diesel vehicles mainly 
during specific catalyst temperature conditions conducive to 
N2O formation. Specifically, N2O can be generated 
during periods of emission hardware warm-up when rising catalyst 
temperatures pass through the temperature window when N2O 
formation potential is possible. For current heavy-duty gasoline 
engines with conventional three-way catalyst technology, N2O 
is not generally produced in significant amounts because the time the 
catalyst spends at the critical temperatures during warm-up is short. 
This is largely due to the need to quickly reach the higher 
temperatures necessary for high catalyst efficiency to achieve emission 
compliance of criteria pollutants. N2O formation is 
generally only a concern with diesel and potentially with future 
gasoline lean-burn engines with compromised NOX emissions 
control systems. If the risk for N2O formation is not 
factored into the design of the controls, these systems can but need 
not be designed in a way that emphasizes efficient NOX 
control while allowing the formation of significant quantities of 
N2O. However, these future advanced gasoline and diesel 
technologies do not inherently require N2O formation to 
properly control NOX. Pathways exist today that meet 
criteria emission standards that would not compromise N2O 
emissions in future systems as observed in current production engine 
and vehicle testing \175\ which would also work for future diesel and 
gasoline technologies. Manufacturers would need to use appropriate 
technologies and temperature controls during future development 
programs with the objective to optimize for both NOX and 
N2O control. Therefore, future designs and controls at 
reducing criteria emissions would need to take into account the balance 
of reducing these emissions with the different control approaches while 
also preventing inadvertent N2O formation, much like the 
path taken in current heavy-duty compliant engines and vehicles. 
Alternatively, manufacturers who find technologies that reduce criteria 
or CO2 emissions but see increases N2O emissions 
beyond the cap could choose to offset N2O emissions with 
reduction in CO2 as allowed in the CO2eq option 
discussed in Section II.E.3.
---------------------------------------------------------------------------

    \175\ Memorandum ``N2O Data from EPA Heavy-Duty 
Testing''.
---------------------------------------------------------------------------

    EPA is finalizing an N2O emission standard that we 
believe would be met by most current-technology gasoline and diesel 
vehicles at essentially no cost to the vehicle, though the agency is 
accounting for additional N2O measurement equipment costs. 
EPA believes that heavy-duty emission standards since 2008 model year, 
specifically the very stringent NOX standards for both 
engine and chassis certified engines, directly result in stringent 
N2O control. It is believed that the current emission 
control technologies used to meet the stringent NOX 
standards achieve the maximum feasible reductions and that no 
additional technologies are recognized that would result in additional 
N2O reductions. As noted, N2O formation in 
current catalyst systems occurs, but their emission levels are 
inherently low, because the time the catalyst spends at the critical 
temperatures during warm-up when N2O can form is short. At 
the same time, we believe that the standard would ensure that the 
design of advanced NOX control systems for future diesel and 
lean-burn gasoline vehicles would control N2O emission 
levels. While current NOX control approaches used on current 
heavy-duty diesel vehicles do not compromise N2O emissions 
and actually result in N2O control, we believe that the 
standards would discourage any new emission control designs for diesels 
or lean-burn gasoline vehicles that achieve criteria emissions 
compliance at the cost of increased N2O emissions. Thus, the 
standard would cap N2O emission levels, with the expectation 
that current gasoline and diesel vehicle control approaches that comply 
with heavy-duty vehicle emission standards for NOX would not 
increase their emission levels, and that the cap would ensure that 
future diesel and lean-burn gasoline vehicles with advanced 
NOX controls would appropriately control their emissions of 
N2O.

[[Page 57190]]

(a) Heavy-Duty Pickup Truck and Van N2O Exhaust Emission 
Standard
    EPA is finalizing the proposed per-vehicle N2O emission 
standard of 0.05 g/mi, measured over the Light-duty FTP and HFET drive 
cycles. Similar to the CO2 standard approach, the 
N2O emission level of a vehicle would be a composite of the 
Light-duty FTP and HFET cycles with the same 55 percent city weighting 
and 45 percent highway weighting. The standard would become effective 
in model year 2014 for all HD pickups and vans that are subject to the 
CO2 emission requirements. Averaging between vehicles would 
not be allowed. The standard is designed to prevent increases in 
N2O emissions from current levels, i.e., a no-backsliding 
standard.
    The N2O standard level is approximately two times the 
average N2O level of current gasoline and diesel heavy-duty 
trucks that meet the NOX standards effective since 2008 
model year.\176\ Manufacturers typically use design targets for 
NOX emission levels at approximately 50 percent of the 
standard, to account for in-use emissions deterioration and normal 
testing and production variability, and we expect manufacturers to 
utilize a similar approach for N2O emission compliance. We 
are not adopting a more stringent standard for current gasoline and 
diesel vehicles because the stringent heavy-duty NOX 
standards already result in significant N2O control, and we 
do not expect current N2O levels to rise for these vehicles 
particularly with expected manufacturer compliance margins.
---------------------------------------------------------------------------

    \176\ Memorandum ``N2O Data from EPA Heavy-Duty 
Testing.''
---------------------------------------------------------------------------

    Diesel heavy-duty pickup trucks and vans with advanced emission 
control technology are in the early stages of development and 
commercialization. As this segment of the vehicle market develops, the 
final N2O standard would require manufacturers to 
incorporate control strategies that minimize N2O formation. 
Available approaches include using electronic controls to limit 
catalyst conditions that might favor N2O formation and 
considering different catalyst formulations. While some of these 
approaches may have associated costs, EPA believes that they will be 
small compared to the overall costs of the advanced NOX 
control technologies already required to meet heavy-duty standards.
    The light-duty GHG rule requires that manufacturers begin testing 
for N2O by 2015 model year. The manufacturers of complete 
pickup trucks and vans (Ford, General Motors, and Chrysler) are already 
impacted by the light-duty GHG rule and will therefore have this 
equipment and capability in place for the timing of this rulemaking.
    Overall, we believe that manufacturers of HD pickups and vans (both 
gasoline and diesel) would meet the standard without implementing any 
significantly new technologies, only further refinement of their 
existing controls, and we do not expect there to be any significant 
costs associated with this standard.
(b) Heavy-Duty Engine N2O Exhaust Emission Standard
    EPA proposed a per engine N2O emissions standard of 0.05 
g/bhp-hr for heavy-duty engines, but is finalizing a standard of 0.10 
g/bhp-hr based on additional data submitted to the agency which better 
represents the full range of current diesel and gasoline engine 
performance. The final N2O standard becomes effective in 
2014 model year for diesel engines, as proposed. However, EPA is 
finalizing N2O standards for gasoline engines that become 
effective in 2016 model year to align with the first year of the 
CO2 gasoline engine standards. Without this alignment, 
manufacturers would not have any flexibility, such as CO2eq 
credits, in meeting the N20 cap and therefore would not have 
any recourse to comply if an engine's N2O emissions were 
above the standard. The standard remains the same over the useful life 
of the engine. The N2O emissions would be measured over the 
composite Heavy-duty FTP cycle because it is believed that this cycle 
poses the highest risk for N2O formation versus the 
additional heavy-duty compliance cycles. The agencies received comments 
from industry suggesting that the N2O and CH4 
emissions be evaluated over the same test cycle required for 
CO2 emissions compliance. In other words, the commenters 
wanted to have the N2O emissions measured over the SET for 
engines installed in tractors. The agencies are not adopting this 
approach for the final action because we do not have sufficient data to 
set the appropriate N2O level using the SET. The agencies 
are not requiring any additional burden by requiring the measurement to 
be conducted over the Heavy-Duty FTP cycle because it is already 
required for criteria emissions. Averaging of N2O emissions 
between HD engines will not be allowed. The standard is designed to 
prevent increases in N2O emissions from current levels, 
i.e., a no-backsliding standard.
    The proposed N2O level was twice the average 
N2O level of primarily pre-2010 model year diesel engines as 
demonstrated in the ACES Study and in EPA's testing of two additional 
engines with selective catalytic reduction aftertreatement 
systems.\177\ Manufacturers typically use design targets for 
NOX emission levels of about 50 percent of the standard, to 
account for in-use emissions deterioration and normal testing and 
production variability, and manufacturers are expected to utilize a 
similar approach for N2O emission compliance.
---------------------------------------------------------------------------

    \177\ Coordinating Research Council Report: ACES Phase 1 of the 
Advanced Collaborative Emissions Study, 2009. (This study included 
detailed chemical characterization of exhaust species emitted from 
four 2007 model year heavy heavy diesel engines).
---------------------------------------------------------------------------

    EPA sought comment about deterioration factors for N2O 
emissions. See 75 FR 74208. Industry stakeholders recommended that the 
agency define a DF of zero. While we believe it is also possible that 
N2O emissions will not deteriorate in use, very little data 
exist for aged engines and vehicles. Therefore, the value we are 
assigning is conservative, specifically additive DF of 0.02 g/bhp-hr. 
While the value is conservative, it is small enough to allow compliance 
for all engines except those very close to the standards. For engines 
too close to the standard to use the assigned DFs, the manufacturers 
would need to demonstrate via engineering analysis that deterioration 
is less than assigned DF.
    EPA sought additional data on the level of the proposed 
N2O level of 0.05 g/bhp-hr. See 75 FR 74208. The agency 
received additional data of 2010 model year engines from the Engine 
Manufacturers Association.\178\ The agencies reanalyzed a new data set, 
as shown in Table II-22, to derive the final N2O standard of 
0.10 g/bhp-hr with a defined deterioration factor of 0.02 g/bhp-hr.
---------------------------------------------------------------------------

    \178\ Engine Manufacturers Association. EMA N2O Email 
03--22--2011. See Docket EPA-HQ-OAR-2010-0162.

[[Page 57191]]



                     Table II-22--N2O Data Analysis
------------------------------------------------------------------------
                                                           Composite FTP
                                            Rated power      cycle N2O
              Engine family                    (HP)       result  (g/bhp-
                                                                hr)
------------------------------------------------------------------------
EPA Data of 2007 Engine with SCR........  ..............           0.042
EPA Data of 2010 Production Intent        ..............           0.037
 Engine.................................
A.......................................             450          0.0181
A.......................................             600          0.0151
B.......................................             360          0.0326
C.......................................             380          0.0353
D.......................................             560          0.0433
D.......................................             455          0.0524
E.......................................             600          0.0437
F.......................................             500          0.0782
G.......................................             483          0.1127
H.......................................             385          0.0444
H.......................................             385          0.0301
H.......................................             385          0.0283
J.......................................             380          0.0317
========================================================================
                                                    Mean           0.043
                                                2 * Mean            0.09
------------------------------------------------------------------------

    Engine emissions regulations do not currently require testing for 
N2O. The Mandatory GHG Reporting final rule requires 
reporting of N2O and requires that manufacturers either 
measure N2O or use a compliance statement based on good 
engineering judgment in lieu of direct N2O measurement (74 
FR 56260, October 30, 2009). The light-duty GHG final rule allows 
manufacturers to provide a compliance statement based on good 
engineering judgment through the 2014 model year, but requires 
measurement beginning in 2015 model year (75 FR 25324, May 7, 2010). 
EPA is finalizing a consistent approach for heavy-duty engine 
manufacturers which allows them to delay direct measurement of 
N2O until the 2015 model year.
    Manufacturers without the capability to measure N2O by 
the 2015 model year would need to acquire and install appropriate 
measurement equipment in response to this final program. EPA has 
established four separate N2O measurement methods, all of 
which are commercially available today. EPA expects that most 
manufacturers would use either photo-acoustic measurement equipment for 
stand-alone, existing FTIR instrumentation at a cost of $50,000 per 
unit or upgrade existing emission measurement systems with NDIR 
analyzers for $25,000 per test cell.
    Overall, EPA believes that manufacturers of heavy-duty engines, 
both gasoline and diesel, would meet the final standard without 
implementing any new technologies, and beyond relatively small 
facilities costs for any company that still needs to acquire and 
install N2O measurement equipment, EPA does not project that 
manufacturers would incur significant costs associated with this final 
N2O standard.
    EPA is not adopting any vehicle-level N2O standards for 
heavy-duty vocational vehicles and combination tractors. The 
N2O emissions would be controlled through the heavy-duty 
engine portion of the program. The only requirement of those vehicle 
manufacturers to comply with the N2O requirements is to 
install a certified engine.
(2) What is EPA's approach to controlling CH4?
    CH4 is greenhouse gas with a GWP of 25. It accounts for 
about 0.03 percent of the greenhouse gases from heavy-duty trucks.\179\
---------------------------------------------------------------------------

    \179\ Value adapted from ``Inventory of U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2007. April 2009.
---------------------------------------------------------------------------

    EPA is finalizing a standard that would cap CH4 emission 
levels, with the expectation that current heavy-duty vehicles and 
engines meeting the heavy-duty emission standards would not increase 
their levels as explained earlier due to robust current controls and 
manufacturer compliance margin targets. It would ensure that emissions 
would be addressed if in the future there are increases in the use of 
natural gas or any other alternative fuel. EPA believes that current 
heavy-duty emission standards, specifically the NMHC standards for both 
engine and chassis certified engines directly result in stringent 
CH4 control. It is believed that the current emission 
control technologies used to meet the stringent NMHC standards achieve 
the maximum feasible reductions and that no additional technologies are 
recognized that would result in additional CH4 reductions. 
The level of the standard would generally be achievable through normal 
emission control methods already required to meet heavy-duty emission 
standards for hydrocarbons and EPA is therefore not attributing any 
cost to this part of the final action. Since CH4 is produced 
in gasoline and diesel engines similar to other hydrocarbon components, 
controls targeted at reducing overall NMHC levels generally also work 
at reducing CH4 emissions. Therefore, for gasoline and 
diesel vehicles, the heavy-duty hydrocarbon standards will generally 
prevent increases in CH4 emissions levels. CH4 
from heavy-duty vehicles is relatively low compared to other GHGs 
largely due to the high effectiveness of the current heavy-duty 
standards in controlling overall HC emissions.
    EPA believes that this level for the standard would be met by 
current gasoline and diesel trucks and vans, and would prevent 
increases in future CH4 emissions in the event that 
alternative fueled vehicles with high methane emissions, like some past 
dedicated compressed natural gas vehicles, become a significant part of 
the vehicle fleet. Currently EPA does not have separate CH4 
standards because, unlike other hydrocarbons, CH4 does not 
contribute significantly to ozone formation.\180\ However, 
CH4 emissions levels in the gasoline and diesel heavy-duty 
truck fleet have nevertheless

[[Page 57192]]

generally been controlled by the heavy-duty HC emission standards. Even 
so, without an emission standard for CH4, future emission 
levels of CH4 cannot be guaranteed to remain at current 
levels as vehicle technologies and fuels evolve.
---------------------------------------------------------------------------

    \180\ But See Ford Motor Co. v. EPA, 604 F. 2d 685 (DC Cir. 
1979) (permissible for EPA to regulate CH4 under CAA 
section 202(b)).
---------------------------------------------------------------------------

    In recent model years, a small number of heavy-duty trucks and 
engines were sold that were designed for dedicated use of natural gas. 
While emission control designs on these recent dedicated natural gas-
fueled vehicles demonstrate CH4 control can be as effective 
as on gasoline or diesel equivalent vehicles, natural gas-fueled 
vehicles have historically generated significantly higher 
CH4 emissions than gasoline or diesel vehicles. This is 
because the fuel is predominantly methane, and most of the unburned 
fuel that escapes combustion without being oxidized by the catalyst is 
emitted as methane. However, even if these vehicles meet the heavy-duty 
hydrocarbon standard and appear to have effective CH4 
control by nature of the hydrocarbon controls, the heavy-duty standards 
do not require CH4 control and therefore some natural gas 
vehicle manufacturers have invested very little effort into methane 
control. While the final CH4 cap standard should not require 
any different emission control designs beyond what is already required 
to meet heavy-duty hydrocarbon standards on a dedicated natural gas 
vehicle (i.e., feedback controlled 3-way catalyst), the cap will ensure 
that systems provide robust control of methane much like a gasoline-
fueled engine. We are not finalizing more stringent CH4 
standards because we believe that the controls used to meet current 
heavy-duty hydrocarbon standards should result in effective 
CH4 control when properly implemented. Since CH4 
is already measured under the current heavy-duty emissions regulations 
(so that it may be subtracted to calculate NMHC), the final standard 
will not result in additional testing costs.
(a) Heavy-Duty Pickup Truck and Van CH4 Standard
    EPA is finalizing the proposed CH4 emission standard of 
0.05 g/mi as measured on the Light-duty FTP and HFET drive cycles, to 
apply beginning with model year 2014 for HD pickups and vans subject to 
the CO2 standards. Similar to the CO2 standard 
approach, the CH4 emission level of a vehicle will be a 
composite of the Light-duty FTP and HFET cycles, with the same 55 
percent city weighting and 45 percent highway weighting.
    The level of the standard is approximately two times the average 
heavy-duty gasoline and diesel truck and van levels.\181\ As with 
N2O, this standard level recognizes that manufacturers 
typically set emissions design targets with a compliance margin of 
approximately 50 percent of the standard. Thus, we believe that the 
standard should be met by current gasoline vehicles with no increase 
from today's CH4 levels. Similarly, since current diesel 
vehicles generally have even lower CH4 emissions than 
gasoline vehicles, we believe that diesels will also meet the standard 
with a larger compliance margin resulting in no change in today's 
CH4 levels.
---------------------------------------------------------------------------

    \181\ Memorandum ``CH4 Data from 2010 and 2011 Heavy-
Duty Vehicle Certification Tests''.
---------------------------------------------------------------------------

(b) Heavy-Duty Engine CH4 Exhaust Emission Standard
    EPA is adopting a heavy-duty engine CH4 emission 
standard of 0.10 g/hp-hr with a defined deterioration factor of 0.02 g/
bhp-hr as measured on the composite Heavy-duty FTP, to apply beginning 
in model year 2014 for diesel engines and in 2016 model year for 
gasoline engines. EPA is adopting a different CH4 standard 
than proposed based on additional data submitted to the agency which 
better represents the full range of current diesel and gasoline engine 
performance. EPA is adopting CH4 standards for gasoline 
engines that become effective in 2016 model year to align with the 
first year of the gasoline engine CO2 standards. Without 
this alignment, manufacturers would not have any flexibility, such as 
CO2eq credits, in meeting the CH4 cap and 
therefore would not be able to sell any engine with a CH4 
level above the standard. The final standard would cap CH4 
emissions at a level currently achieved by diesel and gasoline heavy-
duty engines. The level of the standard would generally be achievable 
through normal emission control methods already required to meet 2007 
emission standards for NMHC and EPA is therefore not attributing any 
cost to this part of this program (see 40 CFR 86.007-11).
    The level of the final CH4 standard is twice the average 
CH4 emissions from gasoline engines from General Motors in 
addition to the four diesel engines in the ACES study.\182\ As with 
N2O, this final level recognizes that manufacturers 
typically set emission design targets at about 50 percent of the 
standard. Thus, EPA believes the final standard would be met by current 
diesel and gasoline engines with little if any technological 
improvements. The agency believes a more stringent CH4 
standard is not necessary due to effective CH4 controls in 
current heavy-duty technologies, since, as discussed above for 
N2O, EPA believes that the challenge of complying with the 
CO2 standards should be the primary focus of the 
manufacturers.
---------------------------------------------------------------------------

    \182\ Coordinating Research Council Report: ACES Phase 1 of the 
Advanced Collaborative Emissions Study, 2009.
---------------------------------------------------------------------------

    CH4 is measured under the current 2007 regulations so 
that it may be subtracted to calculate NMHC. Therefore EPA expects that 
the final standard would not result in additional testing costs.
    EPA is not adopting any vehicle-level CH4 standards for 
heavy-duty combination tractors or vocational vehicles in this final 
action. The CH4 emissions will be controlled through the 
heavy-duty engine portion of the program. The only requirement of these 
truck manufacturers to comply with the CH4 requirements is 
to install a certified engine.
(3) Use of CO2 Credits
    As proposed, if a manufacturer is unable to meet the N2O 
or CH4 cap standards, the EPA program will allow the 
manufacturer to comply using CO2 credits. In other words, a 
manufacturer could offset any N2O or CH4 
emissions above the standard by taking steps to further reduce 
CO2. A manufacturer choosing this option would convert its 
measured N2O and CH4 test results that are in 
excess of the applicable standards into CO2eq to determine 
the amount of CO2 credits required. For example, a 
manufacturer would use 25 Mg of positive CO2 credits to 
offset 1 Mg of negative CH4 credits or use 298 Mg of 
positive CO2 credits to offset 1 Mg of negative 
N2O credits.\183\ By using the Global Warming Potential of 
N2O and CH4, the approach recognizes the inter-
correlation of these compounds in impacting global warming and is 
environmentally neutral for demonstrating compliance with the 
individual emissions caps. Because fuel conversion manufacturers 
certifying under 40 CFR part 85, subpart F do not participate in ABT 
programs, EPA is finalizing a compliance option for fuel conversion 
manufacturers to comply with the N2O and CH4 
standards that is similar to the credit program just described above. 
The compliance option will allow conversion manufacturers, on an 
individual engine family basis, to convert CO2 
overcompliance into CO2 equivalents of N20 and/or 
CH4 that can be subtracted from the CH4 and 
N20 measured values to demonstrate compliance with 
CH4 and/or N20 standards. Other than in the 
limited

[[Page 57193]]

case of N2O for model years 2014-16, we have not finalized 
similar provisions allowing overcompliance with the N2O or 
CH4 standards to serve as a means to generate CO2 
credits because the CH4 and N2O standards are cap 
standards representing levels that all but the worst vehicles should 
already be well below. Allowing credit generation against such cap 
standard would provide a windfall credit without any true GHG 
reduction.
---------------------------------------------------------------------------

    \183\ N2O has a GWP of 298 and CH4 has a 
GWP of 25 according to the IPCC AR4.
---------------------------------------------------------------------------

    The final NHTSA fuel consumption program will not use 
CO2eq, as suggested above. Measured performance to the NHTSA 
fuel consumption standards will be based on the measurement of 
CO2 with no adjustment for N2O and/or 
CH4. For manufacturers that use the EPA alternative 
CO2eq credit, compliance to the EPA CO2 standard 
will not be directly equivalent to compliance with the NHTSA fuel 
consumption standard.
(4) Amendment to Light-Duty Vehicle N2O and CH4 
Standards
    EPA also requested comment on revising a portion of the light-duty 
vehicle standards for N2O and CH4. 75 FR at 
74211. Specifically, EPA requested comments on two additional options 
for manufacturers to comply with N2O and CH4 
standards to provide additional near-term flexibility. EPA is 
finalizing one of those options, as discussed below.
    For light-duty vehicles, as part of the MY 2012-2016 rulemaking, 
EPA finalized standards for N2O and CH4 which 
take effect with MY 2012. 75 FR at 25421-24. Similar to the heavy-duty 
standards discussed in Section II.E above, the light-duty vehicle 
standards for N2O and CH4 were established to cap 
emissions and to prevent future emissions increases, and were generally 
not expected to result in the application of new technologies or 
significant costs for the manufacturers for current vehicle designs. 
EPA also finalized an alternative CO2 equivalent standard 
option, which manufacturers may choose to use in lieu of complying with 
the N2O and CH4 cap standards. The CO2 
equivalent standard option allows manufacturers to fold all 
N2O and CH4 emissions, on a CO2eq 
basis, along with CO2 into their otherwise applicable 
CO2 emissions standard level. For flexible fueled vehicles, 
the N2O and CH4 standards must be met on both 
fuels (e.g., both gasoline and E-85).
    After the light-duty standards were finalized, manufacturers raised 
concerns that for a few of the vehicle models in their existing fleet 
they were having difficulty meeting the N2O and/or 
CH4 standards, especially in the early years of the program 
for a few of the vehicle models in their existing fleet. These 
standards could be problematic in the near term because there is little 
lead time to implement unplanned redesigns of vehicles to meet the 
standards. In such cases, manufacturers may need to either drop vehicle 
models from their fleet or to comply using the CO2 
equivalent alternative. On a CO2eq basis, folding in all 
N2O and CH4 emissions would add 3-4 g/mile or 
more to a manufacturer's overall fleet-average CO2 emissions 
level because the alternative standard must be used for the entire 
fleet, not just for the problem vehicles.\184\ See 75 FR at 74211. This 
could be especially challenging in the early years of the program for 
manufacturers with little compliance margin because there is very 
limited lead time to develop strategies to address these additional 
emissions. As stated at proposal, EPA believed this posed a legitimate 
issue of sufficiency of lead time in the short term, as well as an 
issue of cost, since EPA assumed that the N2O and 
CH4 standards would not result in significant costs for 
existing vehicles. Id. However, EPA expected that manufacturers would 
be able to make technology changes (e.g., calibration or catalyst 
changes) to the few vehicle models not currently meeting the 
N2O and/or CH4 standards in the course of their 
planned vehicle redesign schedules in order to meet the standards.
---------------------------------------------------------------------------

    \184\ 0.030 g/mile CH4 multiplied by a GWP of 25 plus 
0.010 g/mile N2O multiplied by a GWP of 298 results in a 
combined 3.7 g/mile CO2-equivalent value. Manufacturers 
using the default N2O value of 0.10 g/mile prior to MY 
2015 in lieu of measuring N2O would fold in the entire 
0.010 g/mile on a CO2-equivalent basis, or about 3 g/mile 
under the CO2-equivalent option.
---------------------------------------------------------------------------

    Because EPA intended for these standards to be caps with little 
anticipated near-term impact on manufacturer's current product lines, 
EPA requested comment in the heavy-duty vehicle and engine proposal on 
two approaches to provide additional flexibilities in the light-duty 
vehicle program for meeting the N2O and CH4 
standards. 75 FR at 74211. EPA requested comments on the option of 
allowing manufacturers to use the CO2 equivalent approach 
for one pollutant but not the other for their fleet--that is, allowing 
a manufacturer to fold in either CH4 or N2O as 
part of the CO2-equivalent standard. For example, if a 
manufacturer is having trouble complying with the CH4 
standard but not the N2O standard, the manufacturer could 
use the CO2 equivalent option including CH4, but 
choose to comply separately with the applicable N2O cap 
standard.
    EPA also requested comments on an alternative approach of allowing 
manufacturers to use CO2 credits, on a CO2 
equivalent basis, to offset N2O and CH4 emissions 
above the applicable standard. This is similar to the approach proposed 
and being finalized for heavy-duty vehicles as discussed above in 
Section II.E. EPA requested comments on allowing the additional 
flexibility in the light-duty program for MYs 2012-2014 to help 
manufacturers address any near-term issues that they may have with the 
N2O and CH4 standards.
    Commenters providing comment on this issue supported additional 
flexibility for manufacturers, and manufacturers specifically supported 
the heavy-duty vehicle approach of allowing CO2 credits on a 
CO2 equivalent basis to be used to meet the CH4 
and N2O standards. The Alliance of Automobile Manufacturers 
and the American Automotive Policy Council commented that the proposed 
heavy-duty approach represented a significant improvement over the 
approach adopted for light-duty vehicles. Manufacturers support de-
linking N2O and CH4, and commented that the 
formation of the pollutants do not necessarily trend together. 
Manufacturers also commented that a deficit against the N2O 
or CH4 cap would be required to be covered with 
CO2 credits for that model, but the approach does not 
``punish'' manufacturers for using a specific technology (which could 
provide CO2 benefits, e.g., diesel, CNG, etc.) by requiring 
manufacturers to use the CO2-equivalent approach for their 
entire fleet. The Natural Gas Vehicle Interests also supported allowing 
the use of CO2 credits on a CO2-equivalent basis 
for compliance with CH4 standards and urged providing this 
type of flexibility on a permanent basis. The Institute for Policy 
Integrity also submitted comments supportive of providing additional 
flexibility to manufacturers as long as it does not undermine standard 
stringency. This commenter was supportive of either approach discussed 
at proposal.\185\
---------------------------------------------------------------------------

    \185\ The Institute for Policy Integrity questioned whether EPA 
had provided adequate notice of the proposal, given that it appeared 
in the proposed GHG rules for heavy duty vehicles. EPA provided 
notice not only in the preamble, but in the summary of action 
appearing on the first page of the Federal Register notice (``EPA is 
also requesting comment on possible alternative CO2-
equivalent approaches for model year 2012-14 light-duty vehicles''). 
75 FR at 74152. This is ample notice (demonstrated as well by the 
comments received on the issue, including from the Institute).
---------------------------------------------------------------------------

    Manufacturers supported not only adopting the aspects of the heavy-
duty approach noted above, but the entire

[[Page 57194]]

heavy-duty vehicle approach, including two aspects of the program not 
contemplated in EPA's request for comments. First, manufacturers 
commented that EPA incorrectly characterizes the light-duty vehicle 
issues with CH4 and N2O as short-term or early 
lead time issues. For the reasons discussed above, manufacturers 
believe the changes should be made permanent, for the entire 2012-2016 
light-duty rulemaking period and, indeed, in any subsequent rules for 
the light-duty vehicle sector. Second, manufacturers commented that 
N2O and CH4 should be measured on the combined 
55/45 weighting of the FTP and highway cycles, respectively, as these 
cycles are the yardstick for fuel economy and CO2 
measurement. Manufacturers commented that there should not be a 
disconnect between the light-duty and heavy-duty vehicle programs.
    EPA continues to believe that it is appropriate to provide 
additional flexibility to manufacturers to meet the N2O and 
CH4 standards. EPA is thus finalizing provisions allowing 
manufacturers to use CO2 credits, on a CO2-
equivalent basis, to meet the N2O and CH4 
standards, which is consistent with many commenters' preferred 
approach. Manufacturers will have the option of using CO2 
credits to meet N2O and CH4 standards on a test 
group basis as needed for MYs 2012-2016. Because fuel conversion 
manufacturers certifying under 40 CFR part 85, subpart F do not 
participate in ABT programs, EPA is finalizing a compliance option for 
fuel conversion manufacturers to comply with the N2O and 
CH4 standards similar to the credit option just described 
above. The compliance option will allow conversion manufacturers, on an 
individual test group basis, to convert CO2 overcompliance 
into CO2 equivalents of N2O and/or CH4 
that can be subtracted from the CH4 and N2O 
measured values to demonstrate compliance with CH4 and/or 
N2O standards.
    In EPA's request for comments, EPA discussed the new flexibility as 
being needed to address lead time issues for MYs 2012-2014. EPA 
understands that manufacturers are now making technology decisions for 
beyond MY 2014 and that some technologies such as FFVs may have 
difficulty meeting the CH4 and N2O standards, 
presenting manufacturers with difficult decisions of absorbing the 3-4 
g/mile CO2-equivalent emissions fleet wide, making 
significant investments in existing vehicle technologies, or curtailing 
the use of certain technologies.\186\ The CH4 standard, in 
particular, could prove challenging for FFVs because exhaust 
temperatures are lower on E-85 and CH4 is more difficult to 
convert over the catalyst. EPA's initial estimate that these issues 
could be resolved without disrupting product plans by MY 2015 appears 
to be overly optimistic, and therefore EPA is extending the flexibility 
through model year 2016. This change helps ensure that the 
CH4 and N2O standards will not be an obstacle for 
the use of FFVs or other technologies in this timeframe, and at the 
same time, assure that overall fleet average GHG emissions will remain 
at the same level as under the main standards.
---------------------------------------------------------------------------

    \186\ ``Discussions with Vehicle Manufacturers Regarding the 
Light-duty Vehicle CH4 and N2O Standards,'' 
Memorandum from Christopher Lieske to Docket EPA-HQ-OAR-2010-0162.
---------------------------------------------------------------------------

    In response to comments from manufacturers and from the Natural Gas 
Vehicle Interests that the changes to the program make sense and should 
be made on a permanent basis (i.e. for model years after 2016), EPA is 
extending this flexibility through MY 2016 as discussed above, but we 
believe it is premature to decide here whether or not these changes 
should be permanent. EPA may consider this issue further in the context 
of new standards for MYs 2017-2025 in the planned future light-duty 
vehicle rulemaking. With regard to comments on changing the test 
procedures over which N2O and CH4 emissions are 
measured to determine compliance with the standards, the level of the 
standards and the test procedures go hand-in-hand and must be 
considered together. Weighting the highway test result with the city 
test result in the emissions measurement would in most cases reduce the 
overall emissions levels for determining compliance with the standards, 
and would thereby, in effect make the standards less stringent. This 
appears to be inappropriate. In addition, EPA did not request comments 
on changing the level of the N2O and CH4 
standards or the test procedures and it is inappropriate to amend the 
standards for that reason as well.
(5) EPA's Final Standards for Direct Emissions From Air Conditioning
    Air conditioning systems contribute to GHG emissions in two ways--
direct emissions through refrigerant leakage and indirect exhaust 
emissions due to the extra load on the vehicle's engine to provide 
power to the air conditioning system. HFC refrigerants, which are 
powerful GHG pollutants, can leak from the A/C system.\187\ This 
includes the direct leakage of refrigerant as well as the subsequent 
leakage associated with maintenance and servicing, and with disposal at 
the end of the vehicle's life.\188\ The most commonly used refrigerant 
in automotive applications--R134a, has a high GWP of 1430.\189\ Due to 
the high GWP of R134a, a small leakage of the refrigerant has a much 
greater global warming impact than a similar amount of emissions of 
CO2 or other mobile source GHGs.
---------------------------------------------------------------------------

    \187\ The United States has submitted a proposal to the Montreal 
Protocol which, if adopted, would phasedown production and 
consumption of HFCs.
    \188\ The U.S. EPA has reclamation requirements for refrigerants 
in place under Title VI of the Clean Air Act.
    \189\ The global warming potentials used in this rule are 
consistent with the 2007 Intergovernmental Panel on Climate Change 
(IPCC) Fourth Assessment Report. At this time, the global warming 
potential values from the 1996 IPCC Second Assessment Report are 
used in the official U.S. greenhouse gas inventory submission to the 
United Nations Framework Convention on Climate Change (per the 
reporting requirements under that international convention, which 
were last updated in 2006).
---------------------------------------------------------------------------

    Heavy-duty air conditioning systems today are similar to those used 
in light-duty applications. However, differences may exist in terms of 
cooling capacity (such that sleeper cabs have larger cabin volumes than 
day cabs), system layout (such as the number of evaporators), and the 
durability requirements due to longer vehicle life. However, the 
component technologies and costs to reduce direct HFC emissions are 
similar between the two types of vehicles.
    The quantity of GHG refrigerant emissions from heavy-duty trucks 
relative to the CO2 emissions from driving the vehicle and 
moving freight is very small. Therefore, a credit approach is not 
appropriate for this segment of vehicles because the value of the 
credit is too small to provide sufficient incentive to utilize feasible 
and cost-effective air conditioning leakage improvements. For the same 
reason, including air conditioning leakage improvements within the main 
standard would in many instances result in lost control opportunities. 
Therefore, EPA is finalizing the proposed requirement that vehicle 
manufacturers meet a low leakage requirement for all air conditioning 
systems installed in 2014 model year and later trucks, with one 
exception. The agency is not finalizing leakage standards for Class 2b-
8 Vocational Vehicles at this time due to the complexity in the build 
process and the potential for different entities besides the chassis 
manufacturer to be involved in the air conditioning system production 
and installation, with

[[Page 57195]]

consequent difficulties in developing a regulatory system.
    For air conditioning systems with a refrigerant capacity greater 
than 733 grams, EPA is finalizing a leakage standard which is a 
``percent refrigerant leakage per year'' to assure that high-quality, 
low-leakage components are used in each air conditioning system design. 
The agency believes that a single ``gram of refrigerant leakage per 
year'' would not fairly address the variety of air conditioning system 
designs and layouts found in the heavy-duty truck sector. EPA is 
finalizing a standard of 1.50 percent leakage per year for heavy-duty 
pickup trucks and vans and Class 7 and 8 tractors. The final standard 
was derived from the vehicles with the largest system refrigerant 
capacity based on the Minnesota GHG Reporting database.\190\ The 
average percent leakage per year of the 2010 model year vehicles is 2.7 
percent. This final level of reduction is roughly comparable to that 
necessary to generate credits under the light-duty vehicle program. See 
75 FR 25426-25427. Since refrigerant leakage past the compressor shaft 
seal is the dominant source of leakage in belt-driven air conditioning 
systems, the agency recognizes that a single ``percent refrigerant 
leakage per year'' is not feasible for systems with a refrigerant 
capacity of 733 grams or lower, as the minimum feasible leakage rate 
does not continue to drop as the capacity or size of the air 
conditioning system is reduced. The fixed leakage from the compressor 
seal and other system devices results in a minimum feasible yearly 
leakage rate, and further reductions in refrigerant capacity (the 
`denominator' in the percent refrigerant leakage calculation) will 
result in a system which cannot meet the 1.50 percent leakage per year 
standard. EPA does not believe that leakage reducing technologies are 
available at this time which would allow lower capacity systems to meet 
the percent per year standard, so we are finalizing a maximum gram per 
year leakage standard of 11.0 grams per year for air conditioning 
systems with a refrigerant capacity of 733 grams or lower. EPA defined 
the standard, as well as the refrigerant capacity threshold, by 
examining the State of Minnesota GHG Reporting Database for the yearly 
leakage rate from 2010 and 2011 model year pickup trucks. In the 
Minnesota data, the average leak rate for the pickup truck category (16 
unique model and refrigerant capacity combinations) was 13.3 grams per 
year, with an average capacity of 654 grams, resulting in an average 
percent refrigerant leakage per year of 2.0 percent. 4 of the 16 model/
capacity combinations in the reporting data achieved a leak rate 11.0 
grams per year or lower, and this was chosen as the maximum yearly leak 
rate, as several manufacturers have demonstrated that this level of 
yearly leakage is feasible. To avoid a discontinuity between the 
``percent leakage'' and ``leak rate'' standards--where one approach 
would be more or less stringent, depending on the refrigerant 
capacity--a refrigerant capacity of 733 grams was chosen as a threshold 
capacity, below which, the leak rate approach can be used. EPA believes 
this approach of having a leak rate standard for lower capacity systems 
and a percent leakage per year standard for higher capacity systems 
will result in reduced refrigerant emissions from all air conditioning 
systems, while still allowing manufacturers the ability to produce low-
leak, lower capacity systems in vehicles which require them.
---------------------------------------------------------------------------

    \190\ The Minnesota refrigerant leakage data can be found at 
http://www.pca.state.mn.us/climatechange/mobileair.html#leakdata.
---------------------------------------------------------------------------

    Manufacturers can choose to reduce A/C leakage emissions in two 
ways. First, they can utilize leak-tight components. Second, 
manufacturers can largely eliminate the global warming impact of 
leakage emissions by adopting systems that use an alternative, low-
Global Warming Potential (GWP) refrigerant. One alternative 
refrigerant, HFO-1234yf, with a GWP of 4, has been approved for use in 
light-duty passenger vehicles under EPA's Significant New Alternatives 
Program (SNAP). While the scope of this SNAP approval does not include 
heavy-duty highway vehicles, we expect that those interested in using 
this refrigerant in other sectors will petition EPA for broader 
approval of its use in all mobile air conditioning systems. In 
addition, the EPA is currently acting on a petition to de-list R-134a 
as an acceptable refrigerant for new, light-duty passenger vehicles. 
The time frame and scale of R-134a de-listing is yet to be determined, 
but any phase-down of R-134a use will likely take place after this 
rulemaking is in effect. Given that HFO-1234yf is yet to be approved 
for heavy-duty vehicles, and that the time frame for the de-listing of 
R-134a is not known, EPA believes that a leakage standard for heavy-
duty vehicles is still appropriate. If future heavy-duty vehicles adopt 
refrigerants other than R-134a, the calculated refrigerant leak rate 
can be adjusted by multiplying the leak rate by the ratio of the GWP of 
the new refrigerant divided by the GWP of the old refrigerant (e.g. for 
HFO-1234yf replacing R-134a, the calculated leak rate would be 
multiplied by 0.0028, or 4 divided by 1430).
    EPA believes that reducing A/C system leakage is both highly cost-
effective and technologically feasible. The availability of low leakage 
components is being driven by the air conditioning program in the 
light-duty GHG rule which apply to 2012 model year and later vehicles. 
The cooperative industry and government Improved Mobile Air 
Conditioning program has demonstrated that new-vehicle leakage 
emissions can be reduced by 50 percent by reducing the number and 
improving the quality of the components, fittings, seals, and hoses of 
the A/C system.\191\ All of these technologies are already in 
commercial use and exist on some of today's systems, and EPA does not 
anticipate any significant improvements in sealing technologies for 
model years beyond 2014. However, EPA has recognized some manufacturers 
utilize an improved manufacturing process for air conditioning systems, 
where a helium leak test is performed on 100 percent of all o-ring 
fittings and connections after final assembly. By leak testing each 
fitting, the manufacturer or supplier is verifying the o-ring is not 
damaged during assembly (which is the primary source of leakage from o-
ring fittings), and when calculating the yearly leak rate for a system, 
EPA will allow a relative emission value equivalent to a `seal washer' 
can be used in place of the value normally used for an o-ring fitting, 
when 100 percent helium leak testing is performed on those fittings. 
While further updates to the SAE J2727 standard may be forthcoming (to 
address new materials and measurement methods for permeation through 
hoses), EPA believes it is appropriate to include the helium leak test 
update to the leakage calculation method at this time.
---------------------------------------------------------------------------

    \191\ Team 1-Refrigerant Leakage Reduction: Final Report to 
Sponsors, SAE, 2007.
---------------------------------------------------------------------------

    Consistent with the light-duty 2012-2016 MY vehicle rule, we are 
estimating costs for leakage control at $18 (2008$) in direct 
manufacturing costs. Including a low complexity indirect cost 
multiplier (ICM) of 1.14 results in costs of $21 in the 2014 model 
year. A/C control technology is considered to be on the flat portion of 
the learning curve, so costs in the 2017 model year will be $19. These 
costs are applied to all heavy-duty pickups and vans, and to all 
combination tractors. EPA views these costs as minimal and the 
reductions of potent GHGs to be easily feasible and reasonable in the 
lead times provided by the final rules.

[[Page 57196]]

    EPA is requiring that manufacturers demonstrate improvements in 
their A/C system designs and components through a design-based method. 
The method for calculating A/C leakage is based closely on an industry-
consensus leakage scoring method, described below. This leakage scoring 
method is correlated to experimentally-measured leakage rates from a 
number of vehicles using the different available A/C components. Under 
the final approach, manufacturers will choose from a menu of A/C 
equipment and components used in their vehicles in order to establish 
leakage scores, which will characterize their A/C system leakage 
performance and calculate the percent leakage per year as this score 
divided by the system refrigerant capacity.
    Consistent with the light-duty rule, EPA is finalizing a 
requirement that a manufacturer will compare the components of its A/C 
system with a set of leakage-reduction technologies and actions that is 
based closely on that being developed through the Improved Mobile Air 
Conditioning program and SAE International (as SAE Surface Vehicle 
Standard J2727, ``HFC-134a, Mobile Air Conditioning System Refrigerant 
Emission Chart,'' August 2008 version). See generally 75 FR 25426. The 
SAE J2727 approach was developed from laboratory testing of a variety 
of A/C related components, and EPA believes that the J2727 leakage 
scoring system generally represents a reasonable correlation with 
average real-world leakage in new vehicles. Like the cooperative 
industry-government program, our final approach will associate each 
component with a specific leakage rate in grams per year that is 
identical to the values in J2727 and then sum together the component 
leakage values to develop the total A/C system leakage. However, in the 
heavy-duty vehicle program, the total A/C leakage score will then be 
divided by the value of the total refrigerant system capacity to 
develop a percent leakage per year. EPA believes that the design-based 
approach will result in estimates of likely leakage emissions 
reductions that will be comparable to those that would eventually 
result from performance-based testing.
    EPA is not specifying a specific in-use standard for leakage, as 
neither test procedures nor facilities exist to measure refrigerant 
leakage from a vehicle's air conditioning system. However, consistent 
with the light-duty rule, where we require that manufacturers attest to 
the durability of components and systems used to meet the 
CO2 standards (see 75 FR 25689), we will require that 
manufacturers of heavy-duty vehicles attest to the durability of these 
systems, and provide an engineering analysis which demonstrates 
component and system durability.
(6) Indirect Emissions From Air Conditioning
    In addition to direct emissions from refrigerant leakage, air 
conditioning systems also create indirect exhaust emissions due to the 
extra load on the vehicle's engine to provide power to the air 
conditioning system. These indirect emissions are in the form of the 
additional CO2 emitted from the engine when A/C is being 
used due to the added loads. Unlike direct emissions which tend to be a 
set annual leak rate not directly tied to usage, indirect emissions are 
fully a function of A/C usage.
    These indirect CO2 emissions are associated with air 
conditioner efficiency, since air conditioners create load on the 
engine. See 74 FR 49529. However, the agencies are not setting air 
conditioning efficiency standards for vocational vehicles, combination 
tractors, or heavy-duty pickup trucks and vans. The CO2 
emissions due to air conditioning systems in these heavy-duty vehicles 
are minimal compared to their overall emissions of CO2. For 
example, EPA conducted modeling of a Class 8 sleeper cab using the GEM 
to evaluate the impact of air conditioning and found that it leads to 
approximately 1 gram of CO2/ton-mile. Therefore, a projected 
24 percent improvement of the air conditioning system (the level 
projected in the light-duty GHG rulemaking), would only reduce 
CO2 emissions by less than 0.3 g CO2/ton-mile, or 
approximately 0.3 percent of the baseline Class 8 sleeper cab 
CO2 emissions.
(7) Ethanol-Fueled and Electric Vehicles
    Current EPA emissions control regulations explicitly apply to 
heavy-duty engines and vehicles fueled by gasoline, methanol, natural 
gas and liquefied petroleum gas. For multi-fueled vehicles they call 
for compliance with requirements established for each consumed fuel. 
This contrasts with EPA's light-duty vehicle regulations that apply to 
all vehicles generally, regardless of fuel type. As we proposed, we are 
revising the heavy-duty vehicle and engine regulations to make them 
consistent with the light-duty vehicle approach, applying standards for 
all regulated criteria pollutants and GHGs regardless of fuel type, 
including application to all-electric vehicles (EVs). This provision 
will take effect in the 2014 model year, and be optional for 
manufacturers in earlier model years. However, to satisfy the CAA 
section 202(a)(3) lead time constraints, the provision will remain 
optional for all criteria pollutants through the 2015 model year. 
Commenters did not oppose this change in EPA regulations.
    This change primarily affects manufacturers of ethanol-fueled 
vehicles (designed to operate on fuels containing at least 50 percent 
ethanol) and EVs. Flex-fueled vehicles (FFVs) designed to run on both 
gasoline and fuel blends with high ethanol content will also be 
impacted, as they will need to comply with requirements for operation 
both on gasoline and ethanol.
    The regulatory requirements we are finalizing today for 
certification on ethanol follow those already established for methanol, 
such as certification to NMHC equivalent standards and waiver of 
certain requirements. We expect testing to be done using the same E85 
test fuel as is used today for light-duty vehicle testing, an 85/15 
blend of commercially-available ethanol and gasoline vehicle test fuel. 
EV certification will also follow light-duty precedents, primarily 
calling on manufacturers to exercise good engineering judgment in 
applying the regulatory requirements, but will not be allowed to 
generate NOX or PM credits.
    This provision is not expected to result in any significant added 
burden or cost. It is already the practice of HD FFV manufacturers to 
voluntarily conduct emissions testing for these vehicles on E85 and 
submit the results as part of their certification application, along 
with gasoline test fuel results. No changes in certification fees are 
being set in connection with this provision. We expect that there will 
be strong incentives for any manufacturer seeking to market these 
vehicles to also want them to be certified: (1) Uncertified vehicles 
carry a disincentive to potential purchasers who typically have the 
benefit to the environment as one of their reasons for considering 
alternative fuels, (2) uncertified vehicles are not eligible for the 
substantial credits they could likely otherwise generate, (3) EVs have 
no tailpipe or evaporative emissions and thus need no added hardware to 
put them in a certifiable configuration, and (4) emissions controls for 
gasoline vehicles and FFVs are also effective on dedicated ethanol-
fueled vehicles, and thus costly development programs and specialized 
components will not be needed; in fact the highly integrated nature of 
modern automotive products make the emission control systems essential 
to reliable vehicle performance.

[[Page 57197]]

    Regarding technological feasibility, as mentioned above, HD FFV 
manufacturers already test on E85 and the resulting data shows that 
they can meet emissions standards on this fuel. Furthermore, there is a 
substantial body of certification data on light-duty FFVs (for which 
testing on ethanol is already a requirement), showing existing emission 
control technology is capable of meeting even the more stringent Tier 2 
standards in place for light-duty vehicles.
(8) Correction to 40 CFR 1033.625
    In a 2008 final rule that set new locomotive and marine engine 
standards, EPA adopted a provision allowing manufacturers to use a 
limited number of nonroad engines to power switch locomotives provided, 
among other things, that ``the engines were certified to standards that 
are numerically lower than the applicable locomotive standards of this 
part (1033).'' (40 CFR 1033.625(a)). The goal of this provision is to 
encourage the replacement of aging, high-emitting switch locomotives 
with new switch locomotives having very low emissions of PM, 
NOX, and hydrocarbons. However, this provision neglected to 
consider the fact that preexisting nonroad engine emission standards 
for CO were set at levels that were slightly numerically higher than 
those for locomotives. The applicable switch locomotive CO standard of 
part 1033 is 3.2 g/kW-hr (2.4 g/hp-hr), while the applicable nonroad 
engine CO standard is 3.5 g/kW-hr (2.6 g/hp-hr). This is the case even 
for the cleanest final Tier 4 nonroad engines that will phase in 
starting in 2014. Thus, nonroad engines cannot be certified to CO 
standards that are numerically lower than the applicable locomotive 
standards, and the nonroad engine provision is rendered practically 
unusable. This matter was brought to EPA's attention by affected engine 
manufacturers.\192\
---------------------------------------------------------------------------

    \192\ See e-mail correspondence from Timothy A. French, EMA, to 
Donald Kopinski and Charles Moulis, U.S. EPA dated 12/8/10, 
``Switcher Locomotive Flexibility'', docket  EPA-HQ-OAR-
2010-0162.
---------------------------------------------------------------------------

    As indicated above, EPA believes that allowing certification of new 
switch locomotive engines to nonroad engine standards will greatly 
reduce emissions from switch locomotives, and EPA does not believe the 
slight difference in CO standards should prevent this environmentally 
beneficial program. EPA is therefore adopting a corrective technical 
amendment in part 1033. The regulation is being amended at Sec.  
1033.625(a)(2) to add the following italicized text: ``The engines were 
certified to PM, NOX, and hydrocarbon standards that are 
numerically lower than the applicable locomotive standards of this 
part.'' This change is a straightforward correction to restore the 
intended usability of the provision and is not expected to have adverse 
environmental impacts, as nonroad engines have CO emissions that are 
typically well below both the nonroad and locomotive emissions 
standards.
(9) Corrections to 40 CFR Part 600
    EPA adopted changes to fuel economy labeling requirements on July 
6, 2011 (76 FR 39478). We are making the following corrections to these 
regulations in 40 CFR part 600:
     We adopted a requirement to use the specifications of SAE 
J1711 for fuel economy testing related to hybrid-electric vehicles. In 
this final rule, we are extending that requirement to the calculation 
provisions in Sec.  600.114-12. This change was inadvertently omitted 
from the earlier final rule.
     We are correcting an equation in Sec.  600.116-12.
     We are removing text describing label content that differs 
from the sample labels that were published with the final rule. The 
sample labels properly characterize the intended label content.
(10) Definition of Urban Bus
    EPA is adding a new section 86.012-2 to revise the definition of 
``urban bus.'' The new definition will treat engines used in urban 
buses the same as engines used in any other HD vehicle application, 
relying on the definitions of primary intended service class for 
defining which standards and useful life apply for bus engines. This 
change is necessary to allow for installation of engines other than 
HHDDE for hybrid bus applications.

III. Feasibility Assessments and Conclusions

    In this section, NHTSA and EPA discuss several aspects of our joint 
technical analyses. These analyses are common to the development of 
each agency's final standards. Specifically we discuss: the development 
of the baseline used by each agency for assessing costs, benefits, and 
other impacts of the standards, the technologies the agencies evaluated 
and their costs and effectiveness, and the development of the final 
standards based on application of technology in light of the attribute 
based distinctions and related compliance measurement procedures. We 
also discuss the agencies' consideration of standards that are either 
more or less stringent than those adopted.
    This program is based on the need to obtain significant oil savings 
and GHG emissions reductions from the transportation sector, and the 
recognition that there are appropriate and cost-effective technologies 
to achieve such reductions feasibly in the model years of this program. 
The decision on what standard to set is guided by each agency's 
statutory requirements, and is largely based on the need for 
reductions, the effectiveness of the emissions control technology, the 
cost and other impacts of implementing the technology, and the lead 
time needed for manufacturers to employ the control technology. The 
availability of technology to achieve reductions and the cost and other 
aspects of this technology are therefore a central focus of this final 
rulemaking.
    CBD submitted several comments on whether NHTSA had met EISA's 
mandate to set standards ``designed to achieve the maximum feasible 
improvement'' and, to that end, appropriately considered feasible 
technologies in setting the stringency level. CBD stated that the 
proposed rule had been improperly limited to currently available 
technology, and that none of the alternatives contained all of the 
available technology, which it argued violated EISA and the CAA. CBD 
also stated that the phase-in schedule violated the technology-forcing 
intention of EISA, and that the agencies misperceived their statutory 
mandates, arguing that the agencies are required to force technological 
innovation through aggressive standards.
    As demonstrated in the standard-specific discussions later in this 
section of the preamble, the standards adopted in the final program are 
consistent with section 202(a) of the CAA and section 32902(k)(2) of 
EISA. With respect to the EPA rules, we note at the outset, that CBD's 
premise that EPA must adopt ``technology-forcing'' standards for heavy-
duty vehicles and engines is wrong. A technology-forcing standard is 
one that is to be based on standards which will be available, rather 
than technology which is presently available. NRDC v. Thomas, 805 F. 2d 
410, 429 (DC Cir. 1986). Clean Air Act provisions requiring ``the 
greatest degree of emission reduction achievable through the 
application of technology which the Administrator determines will be 
available'' are technology-forcing. See e.g., CAA sections 
202(a)(3)(1);\193\

[[Page 57198]]

213(a)(3). Section 202(a)(1) standards are technology-based, but not 
technology-forcing, requiring EPA to issue standards for a vehicle's 
useful life ``after providing such period as the Administrator finds 
necessary to permit the development and application of the requisite 
technology, giving appropriate consideration to the cost of compliance 
within such period.'' See NACAA v. EPA, 489 F. 3d 1221, 1230 (DC Cir. 
2007) upholding EPA's interpretation of similar language in CAA section 
231(a) as providing even greater leeway to weigh the statutory factors 
than if the provision were technology-forcing. See generally 74 FR at 
49464-465 (Sept. 28. 2009); 75 FR at 74171.
---------------------------------------------------------------------------

    \193\ CBD cites the District Court's opinion in Cent. Valley 
Chrysler-Jeep Inc. v. Goldstene, 529 F. Supp. 2d 1151, 1178 (E.D. 
Cal. 2007) for the proposition that standard-setting provisions of 
Title II of the CAA are technology forcing, but the court was citing 
to the technology-forcing provision section 202(a)(3)(A)(i), which 
is not the applicable authority here.
---------------------------------------------------------------------------

    Section 202(a)(1) of course allows EPA to consider application of 
technologies which will be available as well as those presently 
available, id., and EPA exercised that discretion here. For example, as 
shown below, the agencies carefully considered application of hybrid 
technologies and bottoming cycle technologies for a number of the 
standards. Thus, the critical issue is whether EPA's choice of 
technology penetration on which the standards are premised is 
reasonable considering the statutory factors, the key ones being 
technology feasibility, technology availability in the 2014-2018 model 
years (i.e., adequacy of lead time), and technology cost and cost-
effectiveness. EPA has considerable discretion to weigh these factors 
in a reasonable manner (even for provisions which are explicitly 
technology-forcing, see Sierra Club v. EPA, 325 F. 3d 374, 378 (DC Cir. 
2003)), and has done so here.
    With respect to EISA, 49 U.S.C. section 32902(k)(2) directs NHTSA 
to ``determine in a rulemaking proceeding how to implement a commercial 
medium- and heavy-duty on-highway vehicle and work truck fuel 
efficiency improvement program designed to achieve the maximum feasible 
improvement,'' and ``adopt and implement appropriate test methods, 
measurement metrics, fuel economy standards, and compliance and 
enforcement protocols that are appropriate, cost-effective, and 
technologically feasible for commercial medium- and heavy-duty on-
highway vehicles and work trucks'' NHTSA recognizes that Congress 
intended EPCA (and by extension, EISA, which amended it) to be 
technology-forcing. See Center for Auto Safety v. National Highway 
Traffic Safety Admin., 793 F.2d 1322, 1339 (DC Cir. 1986). However, 
NHTSA believes it is important to distinguish between setting ``maximum 
feasible'' standards, as EPCA/EISA requires, and ``maximum 
technologically feasible'' standards, as CBD would have NHTSA do. The 
agency must weigh all of the statutory factors in setting fuel 
efficiency standards, and therefore may not weigh one statutory factor 
in isolation of others.
    Neither EPCA nor EISA define ``maximum feasible'' in the context of 
setting fuel efficiency or fuel economy standards. Instead, NHTSA is 
directed to consider and meet three factors when determining what the 
maximum feasible standards are--``appropriateness, cost-effectiveness, 
and technological feasibility.'' 32902(k)(2). These factors modify 
``feasible'' in the context of the MD/HD rules beyond a plain meaning 
of ``capable of being done.'' See Center for Biological Diversity v. 
National Highway Traffic Safety Admin., 538 F.3d 1172, 1194 (9th Cir. 
2008). With respect to the setting of standards for light-duty 
vehicles, EPCA/EISA ``gives NHTSA discretion to decide how to balance 
the statutory factors--as long as NHTSA's balancing does not undermine 
the fundamental purpose of EPCA: energy conservation.'' Id. at 1195. 
Where Congress has not directly spoken to a potential issue related to 
such a balancing, NHTSA's interpretation must be a ``reasonable 
accommodation of conflicting policies * * * committed to the agency's 
care by the statute.'' Id. (discussing consideration of consumer 
demand) (internal citations omitted). In the context of the agency's 
light-duty vehicle authority, it was determined that Congress delegated 
the process for setting the maximum feasible standard to NHTSA with 
broad guidelines concerning the factors that the agency must consider. 
Id. (internal citations omitted) (emphasis in original). We believe 
that the same conclusion should be drawn about the statutory provisions 
governing the agency's setting of standards for heavy-duty vehicles. 
Those provisions prescribe statutory factors commensurate to, and 
equally broad as, those prescribed for light-duty. Thus, NHTSA believes 
that it is firmly within our discretion to weigh and balance the 
factors laid out in 32902(k) in a way that is technology-forcing, as 
evidenced by these standards promulgated in this final action, but not 
in a way that requires the application of technology which will not be 
available in the lead time provided by the rules, or which is not cost-
effective, or is cost-prohibitive, as CBD evidently deems mandated.
    As detailed below for each regulatory category, NHTSA has 
considered the appropriateness, cost-effectiveness, and technological 
feasibility of the standards in designing a program to achieve the 
maximum feasible fuel efficiency improvement. It believes that each of 
those criteria is met.
    As described in Section I. F. (2) above, the final standards will 
remain in effect indefinitely at their 2018 or 2019 levels, unless and 
until the standards are revised. CBD maintained that this is a per se 
violation of EISA, arguing that, by definition, standards which are not 
updated continually and regularly cannot be considered maximum 
feasible. NHTSA would like to clarify that the NPRM specified that the 
standards would remain indefinitely ``until amended by a future 
rulemaking action.'' NPRM at 74172. Further, as noted above, NHTSA has 
broad discretion to determine the maximum feasible standards. Unlike 
Sec.  32902(b)(3)(B), which applies to automobiles regulated under 
light-duty CAFE, Sec.  32902(k) does not specify a maximum number of 
years that fuel economy standards for heavy-duty vehicles will be in 
place. Consistent with its broad authority to define maximum feasible 
standards, NHTSA interprets its authority as including the discretion 
to define expiration periods where Congress has not otherwise 
specified. This is particularly appropriate for the heavy-duty sector, 
where fuel efficiency regulation is unprecedented. NHTSA believes that 
it would be unwise to set an expiration period for this first 
rulemaking absent both Congressional direction and a known compelling 
reason for setting a specific date.
    NHTSA believes that the phase-in schedules provide an appropriate 
balance between the technology-forcing purpose of the statute and EISA-
mandated considerations of economic practicability. NHTSA recognizes, 
as noted in the case above, that balancing each statutory factor in 
order to set the maximum feasible standards means that the agency must 
engage in a ``reasonable accommodation of conflicting policies.'' See 
538 F.3d at 1195, supra. Here, the agency has determined that the 
phase-in schedules are one such reasonable accommodation.
    Navistar commented generally that the proposed rule was not 
technologically feasible, stating that the proposed standards assume 
technologies which are not in production for all manufacturers. This is

[[Page 57199]]

not the test for technical feasibility. Under the Clean Air Act, EPA 
needs only to outline a technical path toward compliance with a 
standard, giving plausible reasons for its belief that technology will 
either be developed or applied in the requisite period. NRDC v. EPA, 
655 F. 2d 318, 333-34 (DC Cir. 1981). EPA has done so here with respect 
to the alternative engine standards of particular concern to 
Navistar.\194\ Similarly, NHTSA has previously interpreted 
``technological feasibility'' to mean ``whether a particular method of 
improving fuel economy can be available for commercial application in 
the model year for which a standard is being established.'' 74 FR 
14196, 14216. NHTSA has further clarified that the consideration of 
technological feasibility ``does not mean that the technology must be 
available or in use when a standard is proposed or issued.'' Center for 
Auto Safety v. National Highway Traffic Safety Admin., 793 F.2d 1322, 
1325 n12 (DC Cir. 1986), quoting 42 FR 63, 184, 63, 188 (1977).
---------------------------------------------------------------------------

    \194\ See 40 CFR 1036.620.
---------------------------------------------------------------------------

    Consistent with these previous interpretations, NHTSA believes that 
a technology does not necessarily need to be currently available or in 
use for all regulated parties to be ``technologically feasible'' for 
this program, as long as it is reasonable to expect, based on the 
evidence before the agency, that the technology will be available in 
the model year in which the relevant standard takes effect. The 
agencies provide multiple technology pathways for compliance with a 
standard, allowing each manufacturer to develop technologies which fit 
their current production and research, and the standards are based on 
fleet penetration rates of those technologies. As discussed below, it 
is reasonable to assume that all the technologies on whose performance 
the standards are premised will be available over the period the 
standards are in effect.
    The Institute for Policy Integrity (IPI) commented that the 
agencies should increase the scope and stringency of the final rule to 
the point at which net benefits would be maximized, citing Executive 
Orders 12866 and 13563. EOs 12866 and 13563 instruct agencies, to the 
extent permitted by law, to select, among other things, the regulatory 
approaches which maximize net benefits. NHTSA agrees with IPI about the 
applicability of these EOs and has made every effort to incorporate 
their guidance in drafting this rule.
    Though IPI agreed that the proposed rule was cost-benefit 
justified, IPI further stated that the agencies must implement an 
alternative that provides the maximum net benefits. The agencies 
believe that standards that maximized net benefits would be beyond the 
point of technological feasibility for this first phase of the HD 
National Program. The standards already require the maximum feasible 
fuel efficiency improvements for the HD fleet in the 2014-2018 time 
frame. Thus, even though, the final standards are highly cost-
effective, and standards that maximized net benefits would likely be 
more stringent than those being promulgated in this final action, NHTSA 
believes that standards that maximized net benefits would not be 
appropriate or technologically feasible in the rulemaking time frame. 
The Executive Orders cited by IPI cannot and do not require an agency 
to select a regulatory alternative that is inconsistent with its 
statutory obligations. Thus, the standards adopted in the final rules 
are consistent with the agencies' respective statutory authorities, and 
are not established at levels which are infeasible or cost-ineffective.
    Here, the focus of the standards is on applying fuel efficiency and 
emissions control technology to reduce fuel consumption, CO2 
and other greenhouse gases. Vehicles combust fuel to generate power 
that is used to perform two basic functions: (1) Transport the truck 
and its payload, and (2) operate various accessories during the 
operation of the truck such as the PTO units. Engine-based technology 
can reduce fuel consumption and CO2 emissions by improving 
engine efficiency, which increases the amount of power produced per 
unit of fuel consumed. Vehicle-based technology can reduce fuel 
consumption and CO2 emissions by increasing the vehicle 
efficiency, which reduces the amount of power demanded from the engine 
to perform the truck's primary functions.
    Our technical work has therefore focused on both engine efficiency 
improvements and vehicle efficiency improvements. In addition to fuel 
delivery, combustion, and aftertreatment technology, any aspect of the 
truck that affects the need for the engine to produce power must also 
be considered. For example, the drag due to aerodynamics and the 
resistance of the tires to rolling both have major impacts on the 
amount of power demanded of the engine while operating the vehicle.
    The large number of possible technologies to consider and the 
breadth of vehicle systems that are affected mean that consideration of 
the manufacturer's design and production process plays a major role in 
developing the final standards. Engine and vehicle manufacturers 
typically develop many different models based on a limited number of 
platforms. The platform typically consists of a common engine or truck 
model architecture. For example, a common engine platform may contain 
the same configuration (such as inline), number of cylinders, 
valvetrain architecture (such as overhead valve), cylinder head design, 
piston design, among other attributes. An engine platform may have 
different calibrations, such as different power ratings, and different 
aftertreatment control strategies, such as exhaust gas recirculation 
(EGR) or selective catalytic reduction (SCR). On the other hand, a 
common vehicle platform has different meanings depending on the market. 
In the heavy-duty pickup truck market, each truck manufacturer usually 
has only a single pickup truck platform (for example the F series by 
Ford) with common chassis designs and shared body panels, but with 
variations on load capacity of the axles, the cab configuration, tire 
offerings, and powertrain options. Lastly, the combination tractor 
market has several different platforms and the trucks within each 
platform (such as LoneStar by Navistar) have less commonality. Tractor 
manufacturers will offer several different options for bumpers, 
mirrors, aerodynamic fairing, wheels, and tires, among others. However, 
some areas such as the overall basic aerodynamic design (such as the 
grill, hood, windshield, and doors) of the tractor are tied to tractor 
platform.
    The platform approach allows for efficient use of design and 
manufacturing resources. Given the very large investment put into 
designing and producing each truck model, manufacturers of heavy-duty 
pickup trucks and vans typically plan on a major redesign for the 
models every 5 years or more (a key consideration in the choice of the 
five model year duration during which the vehicle standards are phased 
in). Recently, EPA's non-GHG heavy-duty engine program provided new 
emissions standards every three model years. Heavy-duty engine and 
truck manufacturer product plans typically have fallen into three year 
cycles to reflect this regime. While the recent non-GHG emissions 
standards can be handled generally with redesigns of engines and 
trucks, a complete redesign of a new heavy-duty engine or truck 
typically occurs on a slower cycle and often does not align in time due 
to the fact that the manufacturer of engines

[[Page 57200]]

differs from the truck manufacturer. At the redesign stage, the 
manufacturer will upgrade or add all of the technology and make most 
other changes supporting the manufacturer's plans for the next several 
years, including plans related to emissions, fuel efficiency, and 
safety regulations.
    A redesign of either engine or truck platforms often involves a 
package of changes designed to work together to meet the various 
requirements and plans for the model for several model years after the 
redesign. This often involves significant engineering, development, 
manufacturing, and marketing resources to create a new product with 
multiple new features. In order to leverage this significant upfront 
investment, manufacturers plan vehicle redesigns with several model 
years of production in mind. Vehicle models are not completely static 
between redesigns as limited changes are often incorporated for each 
model year. This interim process is called a refresh of the vehicle and 
it generally does not allow for major technology changes although more 
minor ones can be done (e.g., small aerodynamic improvements, etc). 
More major technology upgrades that affect multiple systems of the 
vehicle thus occur at the vehicle redesign stage and not in the time 
period between redesigns.
    As discussed below, there are a wide variety of CO2 and 
fuel consumption reducing technologies involving several different 
systems in the engine and vehicle that are available for consideration. 
Many can involve major changes to the engine or vehicle, such as 
changes to the engine block and cylinder heads or changes in vehicle 
shape to improve aerodynamic efficiency. Incorporation of such 
technologies during the periodic engine, transmission or vehicle 
redesign process would allow manufacturers to develop appropriate 
packages of technology upgrades that combine technologies in ways that 
work together and fit with the overall goals of the redesign. By 
synchronizing with their multi-year planning process, manufacturers can 
avoid the large increase in resources and costs that would occur if 
technology had to be added outside of the redesign process. We 
considered redesign cycles both in our costing and in assessing needed 
the lead time required.
    As described below, the vast majority of technology on whose 
performance the final standards are predicated is commercially 
available and already being utilized to a limited extent across the 
heavy-duty fleet. Therefore the majority of the emission and fuel 
consumption reductions which would result from these final rules would 
result from the increased use of these technologies. EPA and NHTSA also 
believe that these final rules will encourage the development and 
limited use of more advanced technologies, such as advanced 
aerodynamics and hybrid powertrains in some vocational vehicle 
applications.
    In evaluating truck efficiency, NHTSA and EPA have excluded 
consideration of standards which could result in fundamental changes in 
the engine or vehicle's performance. Put another way, none of the 
technology pathways underlying the final standards involve any 
alteration in vehicle utility. For example, the agencies did not 
consider approaches that would necessitate reductions in engine power 
or otherwise limit truck performance. The agencies have thus limited 
the assessment of technical feasibility and resultant vehicle cost to 
technologies which maintain freight utility. Similarly, the agencies' 
choice of attributes on which to base the standards, and the metrics 
used to measure them, are consciously adopted to preserve the utility 
of heavy-duty vehicles and engines.
    The agencies worked together to determine component costs for each 
of the technologies and build up the costs accordingly. For costs, the 
agencies considered both the direct or ``piece'' costs and indirect 
costs of individual components of technologies. For the direct costs, 
the agencies followed a bill of materials approach utilized by the 
agencies in the light-duty 2012-16 MY vehicle rule. A bill of 
materials, in a general sense, is a list of components or sub-systems 
that make up a system--in this case, an item of technology which 
reduces GHG emissions and fuel consumption. In order to determine what 
a system costs, one of the first steps is to determine its components 
and what they cost. NHTSA and EPA estimated these components and their 
costs based on a number of sources for cost-related information. In 
general, the direct costs of fuel consumption-improving technologies 
for heavy-duty pickups and vans are consistent with those used in the 
light-duty 2012-2016 MY vehicle rule, except that the agencies have 
scaled up certain costs where appropriate to accommodate the larger 
size and/or loads placed on parts and systems in the heavy-duty classes 
relative to the light-duty classes. For loose heavy-duty engines, the 
agencies have consulted various studies and have exercised engineering 
judgment when estimating direct costs. For technologies expected to be 
added to vocational vehicles and combination tractors, the agencies 
have again consulted various studies and have used engineering judgment 
to arrive at direct cost estimates. Once costs were determined, they 
were adjusted to ensure that they were all expressed in 2009 dollars 
using a ratio of gross domestic product deflators for the associated 
calendar years.
    Indirect costs were accounted for using the ICM approach explained 
in Chapter 2 of the RIA, rather than using the traditional Retail Price 
Equivalent (RPE) multiplier approach. For the heavy-duty pickup truck 
and van cost projections in this final action, the agencies have used 
ICMs developed for light-duty vehicles (with the exception that here 
return on capital has been incorporated into the ICMs, where it had not 
been in the light-duty rule) primarily because the manufacturers 
involved in this segment of the heavy-duty market are the same 
manufacturers that build light-duty trucks. For the Class 7 and 8 
tractor, vocational vehicle, and heavy-duty engine cost projections in 
this final rulemaking, EPA contracted with RTI International to update 
EPA's methodology for accounting for indirect costs associated with 
changes in direct manufacturing costs for heavy-duty engine and truck 
manufacturers.\195\ In addition to the indirect cost multipliers 
varying by complexity and time frame, there is no reason to expect that 
the multipliers would be the same for engine manufacturers as for truck 
manufacturers. The report from RTI provides a description of the 
methodology, as well as calculations of new indirect cost multipliers. 
The multipliers used here include a factor of 5 percent of direct costs 
representing the return on capital for heavy-duty engines and truck 
manufacturers. These indirect cost multipliers are intended to be used, 
along with calculations of direct manufacturing costs, to provide 
improved estimates of the full additional costs associated with new 
technologies. The agencies did not receive any adverse comments related 
to this methodology.
---------------------------------------------------------------------------

    \195\ RTI International. Heavy-duty Truck Retail Price 
Equivalent and Indirect Cost Multipliers. July 2010.
---------------------------------------------------------------------------

    Details of the direct and indirect costs, and all applicable ICMs, 
are presented in Chapter 2 of the RIA. In addition, for details on the 
ICMs, please refer to the RTI report (See Docket ID EPA-HQ-OAR-2010-
0162-0283). Importantly, the agencies have revised the ICM factors and 
the way that indirect costs are calculated using the ICMs. As a result, 
the ICM factors are now higher, the indirect costs are higher and, 
therefore, technology costs are

[[Page 57201]]

higher. The changes made to the ICMs and the indirect cost calculations 
are discussed in Section VIII of this preamble and are detailed in 
Chapter 2 of the RIA.
    EPA and NHTSA believe that the emissions reductions called for by 
the final standards are technologically feasible at reasonable costs 
within the lead time provided by the final standards, reflecting our 
projections of widespread use of commercially available technology. 
Manufacturers may also find additional means to reduce emissions and 
lower fuel consumption beyond the technical approaches we describe 
here. We encourage such innovation through provisions in our 
flexibility program as discussed in Section IV.
    The remainder of this section describes the technical feasibility 
and cost analysis in greater detail. Further detail on all of these 
issues can be found in the joint RIA Chapter 2.

A. Class 7-8 Combination Tractor

    Class 7 and 8 tractors are used in combination with trailers to 
transport freight.\196\ The variation in the design of these tractors 
and their typical uses drive different technology solutions for each 
regulatory subcategory. The agencies are adopting provisions to treat 
vocational tractors as vocational vehicles instead of as combination 
tractors, as noted in Section II.B. The focus of this section is on the 
feasibility of the standards for combination tractors, not the 
vocational tractors.
---------------------------------------------------------------------------

    \196\ ``Tractor'' is defined in 49 CFR 571.3 to mean ``a truck 
designed primarily for drawing other motor vehicles and not so 
constructed as to carry a load other than a part of the weight of 
the vehicle and the load so drawn.''
---------------------------------------------------------------------------

    EPA and NHTSA collected information on the cost and effectiveness 
of fuel consumption and CO2 emission reducing technologies 
from several sources. The primary sources of information were the 2010 
National Academy of Sciences report of Technologies and Approaches to 
Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles,\197\ 
TIAX's assessment of technologies to support the NAS panel report,\198\ 
EPA's Heavy-duty Lumped Parameter Model,\199\ the analysis conducted by 
the Northeast States Center for a Clean Air Future, International 
Council on Clean Transportation, Southwest Research Institute and TIAX 
for reducing fuel consumption of heavy-duty long haul combination 
tractors (the NESCCAF/ICCT study),\200\ and the technology cost 
analysis conducted by ICF for EPA.\201\ Following on the EISA of 2007, 
the National Research Council appointed a NAS committee to assess 
technologies for improving fuel efficiency of heavy-duty vehicles to 
support NHTSA's rulemaking. The 2010 NAS report assessed current and 
future technologies for reducing fuel consumption, how the technologies 
could be implemented, and identified the potential cost of such 
technologies. The NAS panel contracted with TIAX to perform an 
assessment of technologies which provide potential fuel consumption 
reductions in heavy-duty trucks and engines and the technologies' 
associated capital costs. Similar to the Lumped Parameter model which 
EPA developed to assess the impact and interactions of GHG and fuel 
consumption reducing technologies for light-duty vehicles, EPA 
developed a new version of that model to specifically address the 
effectiveness and interactions of the final pickup truck and light 
heavy-duty engine technologies. The NESCAFF/ICCT study assessed 
technologies available in 2012 through 2017 to reduce CO2 
emissions and fuel consumption of line haul combination tractors and 
trailers. Lastly, the ICF report focused on the capital, maintenance, 
and operating costs of technologies currently available to reduce 
CO2 emissions and fuel consumption in heavy-duty engines, 
combination tractors, and vocational vehicles.
---------------------------------------------------------------------------

    \197\ Committee to Assess Fuel Economy Technologies for Medium- 
and Heavy-Duty Vehicles; National Research Council; Transportation 
Research Board (2010). Technologies and Approaches to Reducing the 
Fuel Consumption of Medium- and Heavy-Duty Vehicles. (``The NAS 
Report'') Washington, DC, The National Academies Press. Available 
electronically from the National Academy Press Web site at http://www.nap.edu/catalog.php?record_id=12845.
    \198\ TIAX, LLC. ``Assessment of Fuel Economy Technologies for 
Medium- and Heavy-Duty Vehicles,'' Final Report to National Academy 
of Sciences, November 19, 2009.
    \199\ U.S. EPA. Heavy-duty Lumped Parameter Model.
    \200\ NESCCAF, ICCT, Southwest Research Institute, and TIAX. 
Reducing Heavy-Duty Long Haul Combination Truck Fuel Consumption and 
CO2 Emissions. October 2009.
    \201\ ICF International. ``Investigation of Costs for Strategies 
to Reduce Greenhouse Gas Emissions for Heavy-Duty On-Road 
Vehicles.'' July 2010. Docket Number EPA-HQ-OAR-2010-0162-0283.
---------------------------------------------------------------------------

(1) What technologies did the agencies consider to reduce the 
CO2 emissions and fuel consumption of combination tractors?
    Manufacturers can reduce CO2 emissions and fuel 
consumption of combination tractors through use of, among others, 
engine, aerodynamic, tire, extended idle, and weight reduction 
technologies. The standards in the final rules are premised on use of 
these technologies. The agencies note that SmartWay trucks are 
available today which incorporate the technologies on whose performance 
the final standards are based. We will also discuss other technologies 
that could potentially be used, such as vehicle speed limiters, 
although we are not basing the final standards on their use for the 
model years covered by this rulemaking, for various reasons discussed 
below.
    In this section we discuss the baseline tractor and engine 
technologies for the 2010 model year, and then discuss the types of 
technologies that the agencies considered to improve performance 
relative to this baseline, while Section III.A.2 discusses the 
technology packages the agencies used to determine the final standard 
levels.
(a) Baseline Tractor & Tractor Technologies
    Baseline tractor: The agencies developed the baseline tractor to 
represent the average 2010 model year tractor. Today there is a large 
spread in aerodynamics in the new tractor fleet. Trucks sold may 
reflect so-called classic styling (as described in Section II.B.3.c), 
or may be sold with aerodynamic packages. Based on our review of 
current truck model configurations and Polk data provided through MJ 
Bradley,\202\ we believe the aerodynamic configuration of the baseline 
new truck fleet is approximately 25 percent Bin I, 70 percent Bin II, 
and 5 percent Bin III (as these bin configurations are explained above 
in Section II.B. (2)(c). The baseline Class 7 and 8 day cab tractor 
consists of an aerodynamic package which closely resembles the Bin I 
package described in Section II.B. (2)(c), baseline tire rolling 
resistance of 7.8 kg/metric ton for the steer tire and 8.2 kg/metric 
ton,\203\ dual tires with steel wheels on the drive axles, and no 
vehicle speed limiter. The baseline tractor for the Class 8 sleeper 
cabs contains the same aerodynamic and tire rolling resistance 
technologies as the baseline day cab, does not include vehicle speed 
limiters, and does not include an idle reduction technology. The 
agencies assume the baseline transmission is a 10 speed manual. The 
agencies received a comment from the ICCT stating that the 0.69 Cd 
baseline for high roof sleepers published in the NPRM is higher than 
existing studies show. ICCT cited three studies

[[Page 57202]]

including a Society of Automotive Engineering paper showing a lower Cd 
for tractor trailers. The agencies based the average Cd for high roof 
sleepers on available in use fleet composition data, combined with an 
assessment of drag coefficient for different truck configurations. The 
agencies are finalizing the 0.69 baseline Cd for high roof sleeper 
based on our assessment for the NPRM. However, we will continue to 
gather information on the composition of the in-use fleet and may alter 
the baseline in a future action, should more data become available that 
demonstrates our estimate is incorrect.
---------------------------------------------------------------------------

    \202\ MJ Bradley. Heavy-duty Market Analysis. May 2009. Page 10.
    \203\ U.S. Environmental Protection Agency. SmartWay Transport 
Partnership July 2010 e-update accessed July 16, 2010, from http://www.epa.gov/smartwaylogistics/newsroom/documents/e-update-july-10.pdf.
---------------------------------------------------------------------------

    Performance from this baseline can be improved by the use of the 
following technologies:
    Aerodynamic technologies: There are opportunities to reduce 
aerodynamic drag from the tractor, but it is difficult to assess the 
benefit of individual aerodynamic features. Therefore, reducing 
aerodynamic drag requires optimizing of the entire system. The 
potential areas to reduce drag include all sides of the truck--front, 
sides, top, rear and bottom. The grill, bumper, and hood can be 
designed to minimize the pressure created by the front of the truck. 
Technologies such as aerodynamic mirrors and fuel tank fairings can 
reduce the surface area perpendicular to the wind and provide a smooth 
surface to minimize disruptions of the air flow. Roof fairings provide 
a transition to move the air smoothly over the tractor and trailer. 
Side extenders can minimize the air entrapped in the gap between the 
tractor and trailer. Lastly, underbelly treatments can manage the flow 
of air underneath the tractor. As discussed in the TIAX report, the 
coefficient of drag (Cd) of a SmartWay sleeper cab high roof tractor is 
approximately 0.60, which is a significant improvement over a truck 
with no aerodynamic features which has a Cd value of approximately 
0.80.\204\ The GEM demonstrates that an aerodynamic improvement of a 
Class 8 high roof sleeper cab with a Cd value of 0.60 (which represents 
a Bin III tractor) provides a 5 percent reduction in fuel consumption 
and CO2 emissions over a truck with a Cd of 0.68.
---------------------------------------------------------------------------

    \204\ See TIAX, Note 198, Page 4-50.
---------------------------------------------------------------------------

    Lower Rolling Resistance Tires: A tire's rolling resistance results 
from the tread compound material, the architecture and materials of the 
casing, tread design, the tire manufacturing process, and its operating 
conditions (surface, inflation pressure, speed, temperature, etc.). 
Differences in rolling resistance of up to 50 percent have been 
identified for tires designed to equip the same vehicle. The baseline 
rolling resistance coefficient for today's fleet is 7.8 kg/metric ton 
for the steer tire and 8.2 kg/metric ton for the drive tire, based on 
sales weighting of the top three manufacturers based on market 
share.\205\ Since 2007, SmartWay trucks have had steer tires with 
rolling resistance coefficients of less than 6.6 kg/metric ton for the 
steer tire and less than 7.0 kg/metric ton for the drive tire.\206\ Low 
rolling resistance (LRR) drive tires are currently offered in both dual 
assembly and single wide-base configurations. Single wide tires can 
offer rolling resistance reduction along with improved aerodynamics and 
weight reduction. The GEM demonstrates that replacing baseline tractor 
tires with tires which meet the Bin I level provides approximately a 4 
percent reduction in fuel consumption and CO2 emissions over 
the prescribed test cycle, as shown in RIA Chapter 2, Figure 2-2.
---------------------------------------------------------------------------

    \205\ See SmartWay, Note 203, above.
    \206\ Ibid.
---------------------------------------------------------------------------

    Weight Reduction: Reductions in vehicle mass reduce fuel 
consumption and GHGs by reducing the overall vehicle mass to be 
accelerated and also through increased vehicle payloads which can allow 
additional tons to be carried by fewer trucks consuming less fuel and 
producing lower emissions on a ton-mile basis. Initially for proposal, 
the agencies considered evaluating vehicle mass reductions on a total 
vehicle basis for combination tractors.\207\ The agencies considered 
defining a baseline vehicle curb weight and the GEM would have used the 
vehicle's actual curb weight to calculate the increase or decrease in 
fuel consumption related to the overall vehicle mass relative to that 
baseline. After considerable evaluation of this issue, including 
discussions with the industry, we decided it would not be possible to 
define a single vehicle baseline mass for the tractors that would be 
appropriate and representative. Actual vehicle curb weights for these 
classes of vehicles vary by thousands of pounds dependent on customer 
features added to vehicles and critical to the function of the vehicle 
in the particular vocation in which it is used. This is true of 
vehicles such as Class 8 tractors considered in this section that may 
appear to be relatively homogenous but which in fact are quite 
heterogeneous.
---------------------------------------------------------------------------

    \207\ The agencies are using the approach of evaluating total 
vehicle mass for heavy-duty pickups and vans where we have more data 
on the current fleet vehicle mass.
---------------------------------------------------------------------------

    This reality led us to the solution we proposed. In the proposal, 
we reflected mass reductions for specific technology substitutions 
(e.g., installing aluminum wheels instead of steel wheels) where we 
could with confidence verify the mass reduction information provided by 
the manufacturer even though we cannot estimate the actual curb weight 
of the vehicle. In this way, we accounted for mass reductions where we 
can accurately account for its benefits.
    For the final rules, based on evaluation of the comments, the 
agencies developed an expanded list of weight reduction opportunities, 
from which the sum of the weight reduction from the technologies 
installed on a specific tractor can be input into the GEM as listed in 
Table II-9 in Section II. The list includes additional components, but 
not materials, from those proposed in the NPRM. For high strength 
steel, the weight reduction value is equal to 10 percent of the 
presumed baseline component weight, as the agencies used a conservative 
value based on the DOE report. We recognize that there may be 
additional potential for weight reduction in new high strength steel 
components which combine the reduction due to the material substitution 
along with improvements in redesign, as evidenced by the studies done 
for light-duty vehicles. In the development of the high strength steel 
component weights, we are only assuming a reduction from material 
substitution and no weight reduction from redesign, since we do not 
have any data specific to redesign of heavy-duty components nor do we 
have a regulatory mechanism to differentiate between material 
substitution and improved design. We are finalizing for wheels that 
both aluminum and light weight aluminum are eligible to be used as 
light-weight materials. Only aluminum and not light weight aluminum can 
be used as a light-weight material for other components. The reason for 
this is data was available for light weight aluminum for wheels but was 
not available for other components.
    As explained in Section II.B above, the agencies continue to 
believe that the 400 pound weight target is appropriate for setting the 
final combination tractor CO2 emissions and fuel consumption 
standards. The agencies agree with the commenter that 400 pounds of 
weight reduction without the use of single wide tires may not be 
achievable for all tractor configurations. The agencies have expanded 
the list of weight reduction components which can be input into the GEM 
in order to provide the manufacturers with additional means to comply 
with the combination tractors and to further encourage reductions in 
vehicle weight. The agencies considered increasing the

[[Page 57203]]

target value beyond 400 pounds given the additional reduction potential 
identified in the expanded technology list; however, lacking 
information on the capacity for the industry to change to these light 
weight components across the board by the 2014 model year, we have 
decided to maintain the 400 pound target. The agencies intend to 
continue to study the potential for additional weight reductions in our 
future work considering a second phase of truck fuel efficiency and GHG 
regulations.
    A weight reduction of 400 pounds applied to a truck which travels 
at 70,000 pounds will have a minimal impact on fuel consumption. 
However, for trucks which operate at the maximum GVWR which occurs 
approximately in one third of truck miles travelled, a reduced tare 
weight will allow for additional payload to be carried. The GEM 
demonstrates that a weight reduction of 400 pounds applied to the 
payload tons for one third of the trips provides a 0.3 percent 
reduction in fuel consumption and CO2 emissions over the 
prescribed test cycle, as shown in Figure 2-3 of RIA Chapter 2.
    Extended Idle Reduction: Auxiliary power units (APU)s, fuel 
operated heaters, battery supplied air conditioning, and thermal 
storage systems are among the technologies available today to reduce 
main engine extended idling from sleeper cabs. Each of these 
technologies reduces the baseline fuel consumption during idling from a 
truck without this equipment (the baseline) from approximately 0.8 
gallons per hour (main engine idling fuel consumption rate) to 
approximately 0.2 gallons per hour for an APU.\208\ EPA and NHTSA agree 
with the TIAX assessment of a 6 percent reduction in overall fuel 
consumption reduction.\209\
---------------------------------------------------------------------------

    \208\ See the RIA Chapter 2 for details.
    \209\ See the 2010 NAS Report, Note 197, above, at 128.
---------------------------------------------------------------------------

    Vehicle Speed Limiters: Fuel consumption and GHG emissions increase 
proportional to the square of vehicle speed. Therefore, lowering 
vehicle speeds can significantly reduce fuel consumption and GHG 
emissions. A vehicle speed limiter (VSL), which limits the vehicle's 
maximum speed, is a simple technology that is utilized today by some 
fleets (though the typical maximum speed setting is often higher than 
65 mph). The GEM shows that using a vehicle speed limiter set at 62 mph 
on a sleeper cab tractor will provide a 4 percent reduction in fuel 
consumption and CO2 emissions over the prescribed test 
cycles over a baseline vehicle without a VSL or one set above 65 
mph.\210\
---------------------------------------------------------------------------

    \210\ The Center for Biological Diversity thought that the 
agencies; were limiting their consideration of vehicle speed 
limiters as a potential control technology due to perceived legal 
constraints. As noted above, vehicle speed limiters are a potential 
control technology for heavy duty vehicles and there is no statutory 
bar on either agency considering the performance of VSLs in 
developing the standards.
---------------------------------------------------------------------------

    Transmission: As discussed in the 2010 NAS report, automatic and 
automated manual transmissions may offer the ability to improve vehicle 
fuel consumption by optimizing gear selection compared to an average 
driver. However, as also noted in the report and in the supporting TIAX 
report, the improvement is very dependent on the driver of the truck, 
such that reductions ranged from 0 to 8 percent.\211\ Well-trained 
drivers would be expected to perform as well or even better than an 
automatic transmission since the driver can see the road ahead and 
anticipate a changing stoplight or other road condition that an 
automatic transmission can not anticipate. However, poorly-trained 
drivers that shift too frequently or not frequently enough to maintain 
optimum engine operating conditions could be expected to realize 
improved in-use fuel consumption by switching from a manual 
transmission to an automatic or automated manual transmission. Although 
we believe there may be real benefits in reduced fuel consumption and 
GHG emissions through the application of dual clutch, automatic or 
automated manual transmission technology, we are not reflecting this 
potential improvement in our standard setting or in our compliance 
model. We have taken this approach because we cannot say with 
confidence what level of performance improvement to expect.
---------------------------------------------------------------------------

    \211\ See TIAX, Note 198, above at 4-70.
---------------------------------------------------------------------------

    Low Friction Transmission, Axle, and Wheel Bearing Lubricants: The 
2010 NAS report assessed low friction lubricants for the drivetrain as 
a 1 percent improvement in fuel consumption based on fleet 
testing.\212\ The light-duty 2012-16 MY vehicle rule and the pickup 
truck portion of this program estimate that low friction lubricants can 
have an effectiveness value between 0 and 1 percent compared to 
traditional lubricants. However, it is not clear if in many heavy-duty 
applications these low friction lubricants could have competing 
requirements like component durability issues requiring specific 
lubricants with different properties than low friction.
---------------------------------------------------------------------------

    \212\ See the 2010 NAS Report, Note 197, page 67.
---------------------------------------------------------------------------

    Hybrid: Hybrid powertrain development in Class 7 and 8 tractors has 
been limited to a few manufacturer demonstration vehicles to date. One 
of the key benefit opportunities for fuel consumption reduction with 
hybrids is less fuel consumption when a vehicle is idling, but the 
standard is already premised on use of extended idle reduction so use 
of hybrid technology would duplicate many of the same emission 
reductions attributable to extended idle reduction. NAS estimated that 
hybrid systems would cost approximately $25,000 per tractor in the 2015 
through the 2020 time frame and provide a potential fuel consumption 
reduction of 10 percent, of which 6 percent is idle reduction which can 
be achieved (less expensively) through the use of other idle reduction 
technologies.\213\ The limited reduction potential outside of idle 
reduction for Class 8 sleeper cab tractors is due to the mostly highway 
operation and limited start-stop operation. Due to the high cost and 
limited benefit during the model years at issue in this action (as well 
as issues regarding sufficiency of lead time (see Section III.2 (a) 
below), the agencies are not including hybrids in assessing standard 
stringency (or as an input to GEM). However as discussed in Section IV, 
the agencies are providing incentives to encourage the introduction of 
advanced technologies including hybrid powertrains in appropriate 
applications.
---------------------------------------------------------------------------

    \213\ See the 2010 NAS Report, Note 197, page 128.
---------------------------------------------------------------------------

    Management: The 2010 NAS report noted many operational 
opportunities to reduce fuel consumption, such as driver training and 
route optimization. The agencies have included discussion of several of 
these strategies in RIA Chapter 2, but are not using these approaches 
or technologies in the standard setting process. The agencies are 
looking to other resources, such as EPA's SmartWay Transport 
Partnership and regulations that could potentially be promulgated by 
the Federal Highway Administration and the Federal Motor Carrier Safety 
Administration, to continue to encourage the development and 
utilization of these approaches.
(b) Baseline Engine & Engine Technologies
    The baseline engine for the Class 8 tractors is a Heavy Heavy-Duty 
Diesel engine with 15 liters of displacement which produces 455 
horsepower. The agencies are using a smaller baseline engine for the 
Class 7 tractors because of the lower combined weights of this class of 
vehicles require less power, thus the baseline is an 11L engine with 
350 horsepower. The agencies

[[Page 57204]]

developed the baseline diesel engine as a 2010 model year engine with 
an aftertreatment system which meets EPA's 0.20 grams of 
NOX/bhp-hr standard with an SCR system along with EGR and 
meets the PM emissions standard with a diesel particulate filter with 
active regeneration. The baseline engine is turbocharged with a 
variable geometry turbocharger. The following discussion of 
technologies describes improvements over the 2010 model year baseline 
engine performance, unless otherwise noted. Further discussion of the 
baseline engine and its performance can be found in Section III.A.2.6 
below.
    With respect to stringency level, the agencies received comments 
from Cummins and Daimler stating that the proposed stringency levels 
were appropriate for the lead-times. Conversely, the agencies received 
comments from several environmental groups (UCS, CATF, ACEEE) 
supporting a greater reduction in engine CO2 emissions and 
fuel consumption based on the NAS report. Navistar also stated that the 
agencies' baseline engine is inappropriate since there is not currently 
a 0.20 NOX compliant engine in production. A discussion of 
how the baseline engine configuration can be found below in Section 
(2)(b)(i).
    Navistar also stated that the baseline engines proposed in the 
NPRM, MY 2010 selective catalytic reduction (SCR)-equipped, could not 
meet the agencies' statutory obligation to set feasible standards, and 
requested instead that MY 2010 engines currently in-use be used to meet 
the feasibility factor. The agencies thus disagree with the statement 
that SCR is infeasible and therefore, the agencies reaffirm that the 
engine used as the baseline engine in the agencies' analysis does 
indeed exist. In fact, several engine families have been certified by 
EPA using SCR technology over the past two years, all of which have met 
the 0.20 g/bhp-hr NOX standard.\214\ EPA disagrees with 
Navistar that SCR engines currently certified do not meet this 
standard. Compliance with the 0.20 g/bhp-hr FTP NOX standard 
is measured based on an engine's performance when tested over a 
specific duty cycle (see 40 CFR 86.007-11(a)(2)). This is also true 
regarding the SET standard (see 40 CFR 86.007-11(a)(3)). Further, the 
FTP and SET tests are average tests, so emissions could go over 0.20 
even for some portion of the test itself. Manufacturers are also 
required to ensure that their engines meet the NTE standard under all 
conditions specified in the regulations (see 40 CFR 86.007-11(a)(4)).
---------------------------------------------------------------------------

    \214\ See 2010 Model Year Engine Certification Data and 2011 
Model Year Engine Certification Data files located in the Docket 
EPA-HQ-OAR-2010-0162.
---------------------------------------------------------------------------

    Several manufacturers have been able to show compliance with these 
standards in applications for certification provided to EPA for several 
engine families. Navistar has provided no information indicating that 
these tests were false or improper. Indeed, Navistar does not appear to 
suggest, or provide any evidence, that engines with working SCR systems 
do not meet the NOX standard. Thus, it is demonstrably false 
to conclude that the NOX standard cannot be met with SCR-
equipped engines.
    A more detailed response to these comments appears in Section 6.2 
of the Response to Comment document for this rule.
    Engine performance for CO2 emissions and fuel 
consumption can be improved by use of the following technologies:
    Improved Combustion Process: Fuel consumption reductions in the 
range of 1 to 3 percent over the baseline diesel engine are identified 
in the 2010 NAS report through improved combustion chamber design, 
higher fuel injection pressure, improved injection shaping and timing, 
and higher peak cylinder pressures.\215\
---------------------------------------------------------------------------

    \215\ See TIAX. Note 198, Page 4-13.
---------------------------------------------------------------------------

    Turbochargers: Improved efficiency of a turbocharger compressor or 
turbine could reduce fuel consumption by approximately 1 to 2 percent 
over variable geometry turbochargers in the market today.\216\ The 2010 
NAS report identified technologies such as higher pressure ratio radial 
compressors, axial compressors, and dual stage turbochargers as design 
paths to improve turbocharger efficiency.
---------------------------------------------------------------------------

    \216\ See TIAX Note 198, Page 4-2.
---------------------------------------------------------------------------

    Higher efficiency air handling processes: To maximize the 
efficiency of such processes, induction systems may be improved by 
manufacturing more efficiently designed flow paths (including those 
associated with air cleaners, chambers, conduit, mass air flow sensors 
and intake manifolds) and by designing such systems for improved 
thermal control. Improved turbocharging and air handling systems must 
include higher efficiency EGR systems and intercoolers that reduce 
frictional pressure loss while maximizing the ability to thermally 
control induction air and EGR. The agencies received comments from 
Honeywell confirming that turbochargers provide a role in reducing the 
CO2 emissions from engines. Other components that offer 
opportunities for improved flow efficiency include cylinder heads, 
ports and exhaust manifolds to further reduce pumping losses. Variable 
air breathing systems such as variable valve actuation may provide 
additional gains at different loads and speeds. The NESCCAF/ICCT study 
indicated up to 1.2 percent reduction could be achieved solely through 
improved EGR systems.
    Low Temperature Exhaust Gas Recirculation: Most medium- and heavy-
duty vehicle diesel engines sold in the U.S. market today use cooled 
EGR, in which part of the exhaust gas is routed through a cooler 
(rejecting energy to the engine coolant) before being returned to the 
engine intake manifold. EGR is a technology employed to reduce peak 
combustion temperatures and thus NOX. Low-temperature EGR 
uses a larger or secondary EGR cooler to achieve lower intake charge 
temperatures, which tend to further reduce NOX formation. If 
the NOX requirement is unchanged, low-temperature EGR can 
allow changes such as more advanced injection timing that will increase 
engine efficiency slightly more than 1 percent.\217\ Because low-
temperature EGR reduces the engine's exhaust temperature, it may not be 
compatible with exhaust energy recovery systems such as 
turbocompounding or a bottoming cycle.
---------------------------------------------------------------------------

    \217\ See TIAX, Note 198, Page 4-13.
---------------------------------------------------------------------------

    Engine Friction Reduction: Reduced friction in bearings, valve 
trains, and the piston-to-liner interface will improve efficiency. Any 
friction reduction must be carefully developed to avoid issues with 
durability or performance capability. Estimates of fuel consumption 
improvements due to reduced friction range from 0 to 2 percent.\218\
---------------------------------------------------------------------------

    \218\ TIAX, Note 198, pg 4-15
---------------------------------------------------------------------------

    Reduced Parasitic Loads: Accessories that are traditionally gear or 
belt driven by a vehicle's engine can be optimized and/or converted to 
electric power. Examples include the engine water pump, oil pump, fuel 
injection pump, air compressor, power-steering pump, cooling fans, and 
the vehicle's air-conditioning system. Optimization and improved 
pressure regulation may significantly reduce the parasitic load of the 
water, air and fuel pumps. Electrification may result in a reduction in 
power demand, because electrically powered accessories (such as the air 
compressor or power steering) operate only when needed if they are 
electrically powered, but they impose a parasitic demand all the time 
if they are engine driven. In other cases, such as

[[Page 57205]]

cooling fans or an engine's water pump, electric power allows the 
accessory to run at speeds independent of engine speed, which can 
reduce power consumption. The TIAX study used 2 to 4 percent fuel 
consumption improvement for accessory electrification, with the 
understanding that electrification of accessories will have more effect 
in short-haul/urban applications and less benefit in line-haul 
applications.\219\ Bendix, in their comments to the agencies, confirmed 
that there are engine accessories available that can improve an 
engine's fuel efficiency.
---------------------------------------------------------------------------

    \219\ See TIAX. Note 198, Page 3-5.
---------------------------------------------------------------------------

    Selective catalytic reduction: This technology is common on 2010 
the medium- and heavy-duty diesel engines used in Class 7 and 8 
tractors (and the agencies therefore have included it as part of the 
baseline engine, as noted above). Because SCR is a highly effective 
NOX aftertreatment approach, it enables engines to be 
optimized to maximize fuel efficiency, rather than minimize engine-out 
NOX. 2010 SCR systems are estimated to result in improved 
engine efficiency of approximately 3 to 5 percent compared to a 2007 
in-cylinder EGR-based emissions system and by an even greater 
percentage compared to 2010 in-cylinder approaches.\220\ As more 
effective low-temperature catalysts are developed, the NOX 
conversion efficiency of the SCR system will increase. Next-generation 
SCR systems could then enable additional efficiency improvements; 
alternatively, these advances could be used to maintain efficiency 
while down-sizing the aftertreatment. We estimate that continued 
optimization of the catalyst could offer 1 to 2 percent reduction in 
fuel use over 2010 model year systems in the 2014 model year.\221\ The 
agencies estimate an additional 1 to 2 percent reduction may be 
feasible in the 2017 model year through additional refinement.
---------------------------------------------------------------------------

    \220\ Stanton, D. ``Advanced Diesel Engine Technology 
Development for High Efficiency, Clean Combustion.'' Cummins, Inc. 
Annual Progress Report 2008 Vehicle Technologies Program: Advanced 
Combustion Engine Technologies, U.S. Department of Energy. Pp 113-
116. December 2008.
    \221\ See TIAX, Note 198, pg. 4-9.
---------------------------------------------------------------------------

    Mechanical Turbocompounding: Mechanical turbocompounding adds a low 
pressure power turbine to the exhaust stream in order to extract 
additional energy, which is then delivered to the crankshaft. Published 
information on the fuel consumption reduction from mechanical 
turbocompounding varies between 2.5 and 5 percent.\222\ Some of these 
differences may depend on the operating condition or duty cycle that 
was considered by the different researchers. The performance of a 
turbocompounding system tends to be highest at full load and much less 
or even zero at light load.
---------------------------------------------------------------------------

    \222\ NESCCAF/ICCT study (p. 54) and TIAX (2009, pp. 3-5).
---------------------------------------------------------------------------

    Electric Turbocompounding: This approach is similar in concept to 
mechanical turbocompounding, except that the power turbine drives an 
electrical generator. The electricity produced can be used to power an 
electrical motor supplementing the engine output, to power electrified 
accessories, or to charge a hybrid system battery. None of these 
systems have been demonstrated commercially, but modeled results by 
industry and DOE have shown improvements of 3 to 5 percent.\223\
---------------------------------------------------------------------------

    \223\ K. G. Duleep of Energy and Environmental Analysis, R. 
Kruiswyk, 2008, pp. 212-214, NESCCAF/ICCT, 2009, p. 54.
---------------------------------------------------------------------------

    Bottoming Cycle: An engine with bottoming cycle uses exhaust or 
other heat energy from the engine to create power without the use of 
additional fuel. The sources of energy include the exhaust, EGR, charge 
air, and coolant. The estimates for fuel consumption reduction range up 
to 10 percent as documented in the 2010 NAS report.\224\ However, none 
of the bottoming cycle or Rankine systems has been demonstrated 
commercially and are currently in only the research stage. See Section 
2.4.2.7 of the RIA and Section II.B above.
---------------------------------------------------------------------------

    \224\ See 2010 NAS Report, Note 197, page 57.
---------------------------------------------------------------------------

(2) Projected Technology Package Effectiveness and Cost
(a) Class 7 and 8 Combination Tractors
    EPA and NHTSA project that CO2 emissions and fuel 
consumption reductions can be feasibly and cost-effectively achieved in 
these rules' time frames through the increased application of 
aerodynamic technologies, LRR tires, weight reduction, extended idle 
reduction technologies, vehicle speed limiters, and engine 
improvements. The agencies believe that hybrid powertrains systems for 
tractors will not be sufficiently developed and the necessary 
manufacturing capacity put in place to base a standard on any 
significant volume of hybrid tractors. The agencies are not aware of 
any full hybrid systems currently developed for long haul tractor 
applications. To date, hybrid systems for tractors have been primarily 
focused on idle shutdown technologies and not the broader energy 
storage and recovery systems necessary to achieve reductions over 
typical vehicle drive cycles. The final standards reflect the potential 
for idle shutdown technologies through the GEM model. Further as 
highlighted by the 2010 NAS report, the agencies do believe that full 
hybrid powertrains have the potential in the longer term to provide 
significant improvements in fuel efficiency and to reduce greenhouse 
gas emissions. However lacking any existing systems or manufacturing 
base, we cannot conclude such technology will be available in the 2014-
2018 timeframe. Developing a full hybrid system itself would be a three 
to five project followed by several more years to put in place 
manufacturing capacity. The agencies are including incentives for the 
use of hybrid technologies to help encourage their development and to 
reward manufacturers that can produce hybrids through prototype and low 
volume production methods. The agencies also are not including 
drivetrain technologies in the standard setting process, as discussed 
in Section II.B.3.h.iv.
    The agencies evaluated each technology and estimated the most 
appropriate application rate of technology into each tractor 
subcategory. The next sections describe the effectiveness of the 
individual technologies, the costs of the technologies, the projected 
application rates of the technologies into the regulatory 
subcategories, and finally the derivation of the final standards.
(i) Baseline Tractor Performance
    The agencies developed the baseline tractor for each subcategory to 
represent an average 2010 model year tractor configured as noted 
earlier. The approach taken by the agencies was to define the 
individual inputs to the GEM, as shown in Table III-1. For example, the 
agencies evaluated the industry's tractor offerings and concluded that 
the average tractor contains a generally aerodynamic shape (such as 
roof fairings) and avoids classic features such as an exhaust stacks at 
the B-pillar, which increases drag. As noted earlier, our assessment of 
the baseline new high roof tractor fleet aerodynamics consists of 
approximately 25 percent Bin I, 70 percent Bin II, and 5 percent Bin 
III tractors. The baseline rolling resistance coefficient for today's 
fleet is 7.8 kg/metric ton for the steer tire and 8.2 kg/metric ton for 
the drive tire, based on sales weighting of the top three

[[Page 57206]]

manufacturers based on market share.\225\ The agencies assumed no 
application of vehicle speed limiters, weight reduction technologies, 
or idle reduction technologies in the baseline tractor. The agencies 
use the inputs in the GEM to derive the baseline CO2 
emissions and fuel consumption of Class 7 and 8 tractors. The results 
are included in Table III-1.
---------------------------------------------------------------------------

    \225\ U.S. Environmental Protection Agency. SmartWay Transport 
Partnership July 2010 e-update accessed July 16, 2010, from http://www.epa.gov/smartwaylogistics/newsroom/documents/e-update-july-10.pdf.

                                                        Table III-1--Baseline Tractor Definitions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Class 7                                                    Class 8
                                    --------------------------------------------------------------------------------------------------------------------
                                                    Day cab                                Day cab                              Sleeper cab
                                    --------------------------------------------------------------------------------------------------------------------
                                       Low roof     Mid roof    High roof     Low roof     Mid roof    High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Aerodynamics (Cd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................         0.77         0.87         0.73         0.77         0.87         0.73         0.77         0.87         0.70
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Steer Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................          7.8          7.8          7.8          7.8          7.8          7.8          7.8          7.8          7.8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Drive Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................          8.2          8.2          8.2          8.2          8.2          8.2          8.2          8.2          8.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Weight Reduction (lb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................            0            0            0            0            0            0            0            0            0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Extended Idle Reduction (gram CO2/ton-mile reduction)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................          N/A          N/A          N/A          N/A          N/A          N/A            0            0            0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Vehicle Speed Limiter
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................  ...........  ...........  ...........  ...........  ...........  ...........  ...........  ...........  ...........
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Engine
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline...........................  2010 MY 11L  2010 MY 11L  2010 MY 11L  2010 MY 15L  2010 MY 15L  2010 MY 15L  2010 MY 15L  2010 MY 15L  2010 MY 15L
                                          Engine       Engine       Engine       Engine       Engine       Engine       Engine       Engine       Engine
--------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                     Table III-2--Class 7 and 8 Tractor Baseline CO2 Emissions and Fuel Consumption
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Class 7                                                    Class 8
                                    --------------------------------------------------------------------------------------------------------------------
                                                    Day cab                                Day cab                              Sleeper cab
                                    --------------------------------------------------------------------------------------------------------------------
                                       Low roof     Mid roof    High roof     Low roof     Mid roof    High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
CO2 (grams CO2/ton-mile)...........          116          128          138           88           95          103           80           89           94
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fuel Consumption (gal/1,000 ton-            11.4         12.6         13.6          8.7          9.4         10.1          7.8          8.7          9.3
 mile).............................
--------------------------------------------------------------------------------------------------------------------------------------------------------

(ii) Tractor Technology Package Definitions
    The agencies' assessment of the final technology effectiveness was 
developed through the use of the GEM in coordination with chassis 
testing of three SmartWay certified Class 8 sleeper cabs. The agencies 
developed the standards through a three-step process. First, the 
agencies developed technology performance characteristics for each 
technology, described below. Each technology is associated with an 
input parameter which is in turn modeled in the GEM. The performance 
levels for the range of Class 7 and 8 tractor aerodynamic packages and 
vehicle technologies are described in Table III-3. Second, the agencies 
combined the technology performance levels with a projected technology 
application rate to determine the GEM inputs used to set the stringency 
of the final standards. Third, the agencies input the parameters

[[Page 57207]]

into GEM and used the output to determine the final CO2 
emissions and fuel consumption levels.
Aerodynamics
    The aerodynamic packages are categorized as Bin I, Bin II, Bin III, 
Bin IV, or Bin V based on the aerodynamic performance determined 
through testing conducted by the manufacturer. A more complete 
description of these aerodynamic packages is included in Chapter 2 of 
the RIA. In general, the CdA values for each package and tractor 
subcategory were developed through EPA's coastdown testing of tractor-
trailer combinations, the 2010 NAS report, and SAE papers.
Tire Rolling Resistance
    The rolling resistance coefficient for the tires was developed from 
SmartWay's tire testing to develop the SmartWay certification, in 
addition to testing a selection of tractor tires as part of this 
program. The tire performance was evaluated in three levels--the 
baseline (average), 15 percent better than the average, and an 
additional 15 percent improvement. The first 15 percent improvement 
represents the threshold used to develop SmartWay certified tires for 
long haul tractors. The second 15 percent threshold represents an 
incremental step for improvements beyond today's SmartWay level and 
represents the best in class rolling resistance of the tires we tested.
Weight Reduction
    The weight reductions were developed from tire manufacturer 
information, the Aluminum Association, the Department of Energy, and 
TIAX, as discussed above in Section II.B.3.e.
Idle Reduction
    The benefits for the extended idle reductions were developed from 
literature, SmartWay work, and the 2010 NAS report. The agencies 
received comments from multiple stakeholders regarding idle reduction 
technologies (IRT). Two commenters asked us to revise the default value 
associated with the IRT technology, and two commenters want to use IRT 
in GEM even without automatic engine shut down (AES). The agencies 
proposed AES after 5 minutes with no exceptions to help ensure that the 
idle reductions are realized in-use. Use of an AES ensures the main 
engine will be shut down, whereas idle reduction technologies alone do 
not provide that level of certainty. Without an automatic shutdown of 
the main engine, actual savings would depend on operator behavior and 
thus be essentially unverifiable. The agencies are finalizing the 
calculation as proposed, along with the automotive engine shutdown 
requirement. Additional details regarding the comments and calculations 
are included in RIA Section 2.5.4.2.
    Several commenters requested that the level of emissions reductions 
vary in GEM by different idle reduction technologies, and one commenter 
requested that the application of battery powered APUs be incentivized. 
The agencies recognize that the level of emission reductions provided 
by different IRT varies, but are adopting a conservative level to 
recognize that some vehicles may be sold with only an AES but may then 
install an IRT in-use. Or some vehicles may be sold with one IRT but 
then choose to install alternative ones in-use. The agencies cannot 
verify the savings which depend on operator behavior.
    One commenter requested that we provide manufacturers with an 
option to allow the AES feature to be reprogammable after a specified 
number of miles or time in service. The agencies recognize that AES may 
impact the resale value of tractors and, in response to comments, are 
adopting provisions for the optional expiration of an AES. Thus, the 
initial buyer could select AES only for the number of miles based on 
the expected time before resale. Similar to vehicle speed limiters, we 
would discount the impact based on the full life of the truck (e.g. 
1,259,000 miles). Additional detail can be found in RIA Section 
2.5.4.2.
Vehicle Speed Limiter
    The agencies are not including vehicle speed limiters in the 
technology package for Class 7 and 8 tractors.
Summary of Technology Performance
    Table III-3 describes the performance levels for the range of Class 
7 and 8 tractor aerodynamic packages and vehicle technologies.

                                                  Table III-3--Class 7 and 8 Tractor Technology Values
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Class 7                                      Class 8
                                                              ------------------------------------------------------------------------------------------
                                                                        Day cab                   Day cab                       Sleeper cab
                                                              ------------------------------------------------------------------------------------------
                                                                 Low/mid                   Low/mid
                                                                   roof      High roof       roof      High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Aerodynamics (Cd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin I........................................................    0.77/0.87         0.79    0.77/0.87         0.79         0.77         0.87         0.75
Bin II.......................................................    0.71/0.82         0.72    0.71/0.82         0.72         0.71         0.82         0.68
Bin III......................................................  ...........         0.63  ...........         0.63  ...........  ...........         0.60
Bin IV.......................................................  ...........         0.56  ...........         0.56  ...........  ...........         0.52
Bin V........................................................  ...........         0.51  ...........         0.51  ...........  ...........         0.47
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Steer Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline.....................................................          7.8          7.8          7.8          7.8          7.8          7.8          7.8
Level I......................................................          6.6          6.6          6.6          6.6          6.6          6.6          6.6
Level II.....................................................          5.7          5.7          5.7          5.7          5.7          5.7          5.7
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Drive Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline.....................................................          8.2          8.2          8.2          8.2          8.2          8.2          8.2
Level I......................................................          7.0          7.0          7.0          7.0          7.0          7.0          7.0
Level II.....................................................          6.0          6.0          6.0          6.0          6.0          6.0          6.0
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 57208]]

 
                                                                  Weight Reduction (lb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Control......................................................          400          400          400          400          400          400          400
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Extended Idle Reduction (gram CO2/ton-mile reduction) \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Control......................................................          N/A          N/A          N/A          N/A            5            5            5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Vehicle Speed Limiter \b\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Control......................................................          N/A          N/A          N/A          N/A          N/A          N/A          N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\a\ While the standards are set based on this value, users would enter another value if AES is not applied or applied for less than the full useful life
  of the engine.
\b\ Vehicle speed limiters are an applicable technology for all Class 7 and 8 tractors, however the standards are not premised on the use of this
  technology.

(iii) Tractor Technology Application Rates
    As explained above, vehicle manufacturers often introduce major 
product changes together, as a package. In this manner the 
manufacturers can optimize their available resources, including 
engineering, development, manufacturing and marketing activities to 
create a product with multiple new features. In addition, manufacturers 
recognize that a truck design will need to remain competitive over the 
intended life of the design and meet future regulatory requirements. In 
some limited cases, manufacturers may implement an individual 
technology outside of a vehicle's redesign cycle.
    With respect to the levels of technology application used to 
develop the final standards, NHTSA and EPA established technology 
application constraints. The first type of constraint was established 
based on the application of fuel consumption and CO2 
emission reduction technologies into the different types of tractors. 
For example, idle reduction technologies are limited to Class 8 sleeper 
cabs using the assumption that day cabs are not used for overnight 
hoteling. A second type of constraint was applied to most other 
technologies and limited their application based on factors reflecting 
the real world operating conditions that some combination tractors 
encounter. This second type of constraint was applied to the 
aerodynamic, tire, and vehicle speed limiter technologies. Table III-4 
specifies the application rates that EPA and NHTSA used to develop the 
final standards. The agencies received a significant number of comments 
related to this second basis. In particular, commenters questioned the 
reasons for not requiring the maximum reduction technology in every 
case. The agencies have not done so because we have concluded that 
within each of these individual vehicle categories there are particular 
applications where the use of the identified technologies would be 
either ineffective or not technically feasible. The addition of 
ineffective technologies provides no environmental or fuel efficiency 
benefit, increases costs and is not a basis upon which to set a maximum 
feasible improvement. For example, the agencies have not required the 
use of full aerodynamic vehicle treatments on 100 percent of tractors 
because we know that in many applications (for example gravel truck 
engaged in local aggregate delivery) the added weight of the 
aerodynamic technologies will increase fuel consumption and hence 
CO2 emissions to a greater degree than the reduction that 
would be accomplished from the more aerodynamic nature of the tractor. 
To simply set the standard based on the largest reduction possible 
estimated narrowly over a single test procedure while ignoring the in-
use effects of the technology would in this case result in a perverse 
outcome that is not in keeping with the agencies' goals or the 
requirements of the CAA and EISA.
Aerodynamics Application Rate
    The impact of aerodynamics on a truck's efficiency increases with 
vehicle speed. Therefore, the usage pattern of the truck will determine 
the benefit of various aerodynamic technologies. Sleeper cabs are often 
used in line haul applications and drive the majority of their miles on 
the highway travelling at speeds greater than 55 mph. The industry has 
focused aerodynamic technology development, including SmartWay 
tractors, on these types of trucks. Therefore the agencies are adopting 
the most aggressive aerodynamic technology application to this 
regulatory subcategory. All of the major manufacturers today offer at 
least one SmartWay truck model. The 2010 NAS Report on heavy-duty 
trucks found that manufacturers indicated that aerodynamic improvements 
which yield 3 to 4 percent fuel consumption reduction or 6 to 8 percent 
reduction in Cd values, beyond technologies used in today's SmartWay 
trucks are achievable.\226\ The aerodynamic application rate for Class 
8 sleeper cab high roof cabs (i.e., the degree of technology 
application on which the stringency of the final standard is premised) 
consists of 20 percent of Bin IV, 70 percent Bin III, and 10 percent 
Bin II reflecting our assessment of the fraction of tractors in this 
segment that can successfully apply these aerodynamic packages.
---------------------------------------------------------------------------

    \226\ See TIAX, Note 198, Page 4-40.
---------------------------------------------------------------------------

    The 90 percent of tractors that we project can either be Bin II or 
Bin III equipped reflects the bulk of Class 8 high roof sleeper cab 
applications. We are not projecting a higher fraction of Bin III 
aerodynamic systems because of the limited lead time for the program 
and the need for these more advanced technologies to be developed and 
demonstrated before being applied across a wider fraction of the fleet. 
Aerodynamic improvements through new tractor designs and the

[[Page 57209]]

development of new aerodynamic components is an inherently slow and 
iterative process. Aerodynamic impacts are highly nonlinear and often 
reflect unexpected interactions between multiple components. Given the 
nature of aerodynamic improvements it is inherently difficult to 
estimate the degree to which improvements can be made beyond previously 
demonstrated levels. The changes required for Bins III and IV reflect 
the kinds of improvements projected in the Department of Energy's 
Supertruck program. That program assumes that such systems can be 
demonstrated on vehicles by 2017. In this case, the agencies are 
projecting that truck OEMs will be able to begin implementing these 
aerodynamic technologies prior to 2017 on a limited scale. Importantly, 
our averaging, banking and trading provisions provide manufacturers 
with the flexibility to implement these technologies over time even 
though the standard changes in a single step.
    The final aerodynamic application for the other tractor regulatory 
categories is less aggressive than for the Class 8 sleeper cab high 
roof. The agencies recognize that there are truck applications which 
require on/off-road capability and other truck functions which restrict 
the type of aerodynamic equipment applicable. We also recognize that 
these types of trucks spend less time at highway speeds where 
aerodynamic technologies have the greatest benefit. The 2002 VIUS data 
ranks trucks by major use.\227\ The heavy trucks usage indicates that 
up to 35 percent of the trucks may be used in on/off-road applications 
or heavier applications. The uses include construction (16 percent), 
agriculture (12 percent), waste management (5 percent), and mining (2 
percent). Therefore, the agencies analyzed the technologies to evaluate 
the potential restrictions that would prevent 100 percent application 
of SmartWay technologies for all of the tractor regulatory 
subcategories.
---------------------------------------------------------------------------

    \227\ U.S. Department of Energy. Transportation Energy Data 
Book, Edition 28-2009. Table 5.7.
---------------------------------------------------------------------------

    As discussed in Section II.B.2.c, in response to comments received 
from manufacturers making some of these same points, the agencies are 
finalizing only two aerodynamic bins for low and mid roof tractors. The 
agencies are reducing the number of bins for these tractors from the 
proposal to reflect the actual range of aerodynamic technologies 
effective in low and mid roof tractor applications. The aerodynamic 
improvements to the bumper, hood, windshield, mirrors, and doors are 
developed for the high roof tractor application and then carried over 
into the low and mid roof applications. As mentioned in Section 
II.B.2.c, the types of designs that would move high roof tractors from 
a Bin III to Bins IV and V include features such as gap reducers and 
integral roof fairings which would not be appropriate on low and mid 
roof tractors. Thus, the agencies are differentiating the aerodynamic 
performance for low- and mid-roof tractors into two bins--Bin I and Bin 
II. The application rates in the low and mid roof categories are the 
same as proposed, but aggregated into just two bins. Bin I for these 
tractors corresponds to the proposed ``Classic'' and ``Conventional'' 
bins and Bin II corresponds to the proposed ``SmartWay,'' ``Advanced 
SmartWay,'' and ``Advanced SmartWay II'' bins.
Low Rolling Resistance Tire Application Rate
    At proposal, the agencies stated that at least one LRR tire model 
is available today that meets the rolling resistance requirements of 
the Level I and Level II tire packages so the 2014 MY should afford 
manufacturers sufficient lead time to install these packages. EPA and 
NHTSA conducted additional evaluation testing on HD tires used for 
tractors. The agencies also received several comments on the 
suitability of low rolling resistance tires for various HD truck 
applications. The summary of the agencies findings and a response to 
issues raised by commenters is presented in Section II.D(1)(a).
    The agencies note that baseline rolling resistance level for tires 
installed on tractors is approximately equivalent to what the agencies 
consider to be low rolling resistance tires for vocational vehicles 
because of the tire manufacturer's focus on improving the rolling 
resistance of tractor tires. For the tire manufacturers to further 
reduce tire rolling resistance, the manufacturers must consider several 
performance criteria that affect tire selection. The characteristics of 
a tire also influence durability, traction control, vehicle handling, 
comfort, and retreadability. A single performance parameter can easily 
be enhanced, but an optimal balance of all the criteria will require 
improvements in materials and tread design at a higher cost, as 
estimated by the agencies. Tire design requires balancing performance, 
since changes in design may change different performance 
characteristics in opposing directions. Similar to the discussion 
regarding lesser aerodynamic technology application in tractor segments 
other than sleeper cab high roof, the agencies believe that the final 
standards should not be premised on 100 percent application of Level II 
tires in all tractor segments given the interference with vehicle 
utility that would result. The agencies are basing their analyses on 
application rates that vary by subcategory recognizing that some 
subcategories require a different balancing of performance versus 
rolling resistance.
Weight Reduction Technology Application Rate
    The agencies proposed setting the 2014 model year tractor standards 
using 100 percent application of a 400 pound weight reduction package. 
Volvo and ATA stated in their comments that not all fleets can use 
single wide tires and if this is the case the 400 pound weight 
reduction cannot be met. The agencies also received comments from MEMA, 
Navistar, American Chemistry Council, the Auto Policy Center, Iron and 
Steel Institute, Arvin Meritor, Aluminum Association, and environmental 
groups and NGOs identifying other potential weight reduction 
opportunities for tractors. As described in Section II.B.3.e above, the 
agencies are adopting an expanded list of weight reduction options 
which can be input into the GEM for the final rulemaking.
    As also explained in that earlier discussion, the agencies, upon 
further analysis, continue to believe that a 400 pound weight reduction 
package is appropriate for tractors in the time frame. As stated in 
Section II.B.2.e above, for tractors where single wide tires are not 
appropriate, the manufacturers have additional options available to 
achieve weight reduction, such as body panels and chassis components as 
documented in the earlier discussion. The agencies have extended the 
list of weight reduction components in order to provide the 
manufacturers with additional means to comply with the combination 
tractors and to further encourage reductions in vehicle weight. The 
agencies considered increasing the target value beyond 400 pounds given 
the additional reduction potential components identified in the 
expanded list; however, lacking information on the capacity for the 
industry to change to these light weight components across the board by 
the 2014 model year, we have decided to maintain the 400 pound target. 
The agencies intend to continue to study the potential for additional 
weight reductions in our future work considering a second phase of 
truck fuel efficiency and GHG regulations.

[[Page 57210]]

Idle Reduction Technology Application Rate
    Idle reduction technologies provide significant reductions in fuel 
consumption and CO2 emissions for Class 8 sleeper cabs and 
are available on the market today, and therefore will be available in 
the 2014 model year. There are several different technologies available 
to reduce idling. These include APUs, diesel fired heaters, and battery 
powered units. Our discussions with manufacturers indicate that idle 
technologies are sometimes installed in the factory, but it is also a 
common practice to have the units installed after the sale of the 
truck. We would like to continue to incentivize this practice and to do 
so in a manner that the emission reductions associated with idle 
reduction technology occur in use. Therefore, as proposed, we are 
allowing only idle emission reduction technologies with include an 
automatic engine shutoff (AES). We are also adopting some override 
provisions in response to comments we received (as explained below). As 
proposed, we are adopting a 100 percent application rate for this 
technology for Class 8 sleeper cabs, even though the current fleet is 
estimated to have a 30 percent application rate. The agencies are 
unaware of reasons why AES with extended idle reduction technologies 
could not be applied to all tractors with a sleeper cab, except those 
deemed a vocational tractor, in the available lead time.
    One commenter stated the application rate of AES should be less 
than 100 percent, but did not recommend an alternative application rate 
or provide justification for a change. The agencies re-evaluated the 
proposed 100 percent application rate and determined that a 100 percent 
application rate for this technology for Class 8 sleeper cabs remains 
appropriate. The agencies have also considered the many comments which 
raised concerns about the proposed mandatory 5 minute automatic engine 
shut down without override capability (in terms of safety, extreme 
temperatures and low battery conditions). To avoid unintended adverse 
impacts, we are adopting limited override provisions. Three of the five 
exceptions are similar to those currently in effect under a California 
Air Resources Board (CARB) regulation. CARB provides AES exceptions (or 
overrides) within its existing heavy-duty vehicle anti-idling laws, 
which were developed to address these same types of concerns. The 
exceptions we are adopting include override capability during exhaust 
emissions control device regeneration, during engine servicing and 
maintenance, when battery state of charge is too low, in extreme 
ambient temperatures, when engine coolant temperature is too low, and 
during PTO operation. The RIA provides more detail about these final 
override provisions in Section 2.5.4.3.
    The agencies received comment that we should extend the idle 
reduction benefits beyond Class 8 sleepers, including Class 7 tractors 
and vocational vehicles. The agencies reviewed literature to quantify 
the amount of idling which is conducted outside of hoteling operations. 
One study, conducted by Argonne National Laboratory, identified several 
different types of trucks which might idle for extended amounts of time 
during the work day.\228\ Idling may occur during the delivery process, 
queuing at loading docks or border crossings, during power take off 
operations, or to provide comfort during the work day. However, the 
study provided only ``rough estimates'' of the idle time and energy use 
for these vehicles. The agencies are not able to appropriately develop 
a baseline of workday idling for the other types of vehicles and 
identify the percent of this idling which could be reduced through the 
use of AES. Absent such information, the agencies cannot justify adding 
substantial cost for AES systems with such uncertain benefits.
---------------------------------------------------------------------------

    \228\ Gaines, L., A. Vyas, J. Anderson. Estimation of Fuel Use 
by Idling Commercial Trucks. January 2006.
---------------------------------------------------------------------------

Vehicle Speed Limiter Application Rate
    Vehicle speed limiters may be used as a technology to meet the 
standard, but in setting the standard we assumed a zero percent 
application rate of vehicle speed limiters. Although we believe vehicle 
speed limiters are a simple, easy to implement, and inexpensive 
technology, we want to leave the use of vehicles speed limiters to the 
truck purchaser. Since truck fleets purchase trucks today with owner 
set vehicle speed limiters, we considered not including VSLs in our 
compliance model. However, we have concluded that we should allow the 
use of VSLs that cannot be overridden by the operator as a means of 
compliance for vehicle manufacturers that wish to offer it and truck 
purchasers that wish to purchase the technology. In doing so, we are 
providing another means of meeting that standard that can lower 
compliance cost and provide a more optimal vehicle solution for some 
truck fleets. For example, a local beverage distributor may operate 
trucks in a distribution network of primarily local roads. Under those 
conditions, aerodynamic fairings used to reduce aerodynamic drag 
provide little benefit due to the low vehicle speed while adding 
additional mass to the vehicle. A vehicle manufacturer could choose to 
install a VSL set a 55 mph for this customer. The resulting truck 
modeled in GEM could meet our final emission standard without the use 
of any specialized aerodynamic fairings. The resulting truck would be 
optimized for its intended application and would be fully compliant 
with our program all at a lower cost to the ultimate truck 
purchaser.\229\
---------------------------------------------------------------------------

    \229\ Ibid.
    The agencies note that because a VSL value can be input into 
GEM, its benefits can be directly assessed with the model and off 
cycle credit applications therefore are not necessary even though 
the standard is not based on performance of VSLs (i.e. VSL is an on-
cycle technology).
---------------------------------------------------------------------------

    As discussed in Section II.B.2.g above, we have chosen not to base 
the standards on performance of VSLs because of concerns about how to 
set a realistic application rate that avoids unintended adverse 
impacts. Although we expect there will be some use of VSL, currently it 
is used when the fleet involved decides it is feasible and practicable 
and increases the overall efficiency of the freight system for that 
fleet operator. However, at this point the agencies are not in a 
position to determine in how many additional situations use of a VSL 
would result in similar benefits to overall efficiency. Therefore, the 
agencies are not premising the final standards on use of VSL, and 
instead will rely on the industry to select VSL when circumstances are 
appropriate for its use. The agencies have not included either the cost 
or benefit due to VSLs in analysis of the program's costs and benefits. 
Implementation of this program may provide greater information for 
using this technology in standard setting in the future. Many 
stakeholders including the American Trucking Association have advocated 
for more widespread use of vehicle speed limits to address fuel 
efficiency and greenhouse gas emissions. The Center for Biological 
Diversity (CBD) argued the agencies should reflect the use of VSLs in 
setting the standard for tractors rather than assuming no VSL use in 
determining the appropriate standard. The agencies have chosen not to 
do so because, as explained, we are not able at this time to quantify 
to potential loss in utility due to the use of VSLs. Absent this 
information, we cannot make a determination regarding the 
reasonableness of setting a standard based on a particular VSL level. 
In

[[Page 57211]]

confirmation, a number of commenters most notably the Owner Operator 
Independent Drivers Association (OOIDA) suggest that VSLs could 
significantly impact the ability of a vehicle to deliver goods against 
a fixed schedule and hence would significantly impact its utility. ATA 
commented that limited flexibility must be built into speed limiters as 
not to interfere with NHTSA planned rulemaking in response to 2006 ATA 
petition and its 2008 Sustainability Plan. Similar comments were 
received from DTNA requesting that the agencies consider any NHTSA 
safety regulations that may also be regulating VSLs. NHTSA plans to 
issue a rule in 2012 addressing the safety performance features of 
VSLs.
    Table III-4 provides the final application rates of each technology 
broken down by weight class, cab configuration, and roof height.

                                       Table III-4--Final Technology Application Rates for Class 7 and 8 Tractors
                                                                      [In percent]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Class 7                                      Class 8
                                                              ------------------------------------------------------------------------------------------
                                                                        Day cab                   Day cab                       Sleeper cab
                                                              ------------------------------------------------------------------------------------------
                                                                 Low/mid                   Low/mid
                                                                   roof      High roof       roof      High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Aerodynamics (Cd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bin I........................................................           40            0           40            0           30           30            0
Bin II.......................................................           60           30           60           30           70           70           10
Bin III......................................................  ...........           60  ...........           60  ...........  ...........           70
Bin IV.......................................................  ...........           10  ...........           10  ...........  ...........           20
Bin V........................................................  ...........            0  ...........            0  ...........  ...........            0
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Steer Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline.....................................................           40           30           40           30           30           30           10
Bin I........................................................           50           60           50           60           60           60           70
Bin II.......................................................           10           10           10           10           10           10           20
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Drive Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline.....................................................           40           30           40           30           30           30           10
Bin I........................................................           50           60           50           60           60           60           70
Bin II.......................................................           10           10           10           10           10           10           20
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Weight Reduction (lb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
400 lb. Weight Reduction.....................................          100          100          100          100          100          100          100
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Extended Idle Reduction (gram CO2/ton-mile reduction)
--------------------------------------------------------------------------------------------------------------------------------------------------------
AES..........................................................          N/A          N/A          N/A          N/A          100          100          100
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Vehicle Speed Limiter
--------------------------------------------------------------------------------------------------------------------------------------------------------
VSL..........................................................            0            0            0            0            0            0            0
--------------------------------------------------------------------------------------------------------------------------------------------------------

(iv) Derivation of the Final Tractor Standards
    The agencies used the technology inputs and final technology 
application rates in GEM to develop the final fuel consumption and 
CO2 emissions standards for each subcategory of Class 7 and 
8 combination tractors. The agencies derived a scenario tractor for 
each subcategory by weighting the individual GEM input parameters 
included in Table III-3 with the application rates in Table III-4. For 
example, the Cd value for a Class 8 Sleeper Cab High Roof scenario case 
was derived as 10 percent times 0.68 plus 70 percent times 0.60 plus 20 
percent times 0.55, which is equal to a Cd of 0.60. Similar 
calculations were done for tire rolling resistance, weight reduction, 
idle reduction, and vehicle speed limiters. To account for the two 
final engine standards, the agencies assumed a compliant engine in 
GEM.\230\ In other words, EPA is finalizing the use of a 2014 model 
year fuel consumption map in GEM to derive the 2014 model year tractor 
standard and a 2017 model year fuel consumption map to derive the 2017 
model year tractor standard.\231\ The agencies then ran GEM with a 
single set of vehicle inputs, as shown in Table III-5, to derive the 
final standards for each subcategory. Additional detail is provided in 
the RIA Chapter 2.
---------------------------------------------------------------------------

    \230\ See Section III.A.2.b below explaining the derivation of 
the engine standards.
    \231\ As explained further in Section V below, EPA would use 
these inputs in GEM even for engines electing to use the alternative 
engine standard.

[[Page 57212]]



                                         Table III-5--GEM Inputs for the Class 7 and 8 Tractor Standard Setting
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Class 7                                                                      Class 8
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Day cab                                                  Day cab                              Sleeper cab
--------------------------------------------------------------------------------------------------------------------------------------------------------
                    Low roof                        Mid roof    High roof     Low roof     Mid roof    High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Aerodynamics (Cd)
--------------------------------------------------------------------------------------------------------------------------------------------------------
0.73............................................         0.84         0.65         0.73         0.84         0.65         0.73         0.84         0.59
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Steer Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
6.99............................................         6.99         6.87         6.99         6.99         6.87         6.87         6.87         6.54
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Drive Tires (CRR kg/metric ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
7.38............................................         7.38         7.26         7.38         7.38         7.26         7.26         7.26         6.92
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Weight Reduction (lb)
--------------------------------------------------------------------------------------------------------------------------------------------------------
400.............................................          400          400          400          400          400          400          400          400
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Extended Idle Reduction (gram CO2/ton-mile reduction)
--------------------------------------------------------------------------------------------------------------------------------------------------------
N/A.............................................          N/A          N/A          N/A          N/A          N/A            5            5            5
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Vehicle Speed Limiter
--------------------------------------------------------------------------------------------------------------------------------------------------------
--..............................................  ...........  ...........  ...........  ...........  ...........  ...........  ...........  ...........
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         Engine
--------------------------------------------------------------------------------------------------------------------------------------------------------
2014/17 MY 11L Engine...........................   2014/17 MY   2014/17 MY   2014/17 MY   2014/17 MY   2014/17 MY   2014/17 MY   2014/17 MY   2014/17 MY
                                                   11L Engine   11L Engine   15L Engine   15L Engine   15L Engine   15L Engine   15L Engine   15L Engine
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The level of the 2014 and 2017 model year final standards and 
percent reduction from the baseline for each subcategory are included 
in Table III-6.

                         Table III-6--Final 2014 and 2017 Model Year Tractor Reductions
----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
                                     2014 Model Year CO2 Grams per Ton-Mile
----------------------------------------------------------------------------------------------------------------
                                                                              Day cab                Sleeper cab
                                                                 -----------------------------------------------
                                                                          Class 7         Class 8         Class
                                                                 -----------------------------------------------
Low Roof........................................................             107              81              68
Mid Roof........................................................             119              88              76
High Roof.......................................................             124              92              75
----------------------------------------------------------------------------------------------------------------
2014-2016 Model Year Gallons of Fuel per 1,000 Ton-Mile \232\
----------------------------------------------------------------------------------------------------------------
                                                                              Day cab                 Sleeper cab
                                                                 -----------------------------------------------
                                                                          Class 7         Class 8         Class
                                                                 -----------------------------------------------
Low Roof........................................................            10.5             8.0             6.7
Mid Roof........................................................            11.7             8.7             7.4
High Roof.......................................................            12.2             9.0             7.3
----------------------------------------------------------------------------------------------------------------
2017 Model Year CO2 Grams per Ton-Mile
----------------------------------------------------------------------------------------------------------------
                                                                              Day cab                 Sleeper cab
                                                                 -----------------------------------------------
                                                                          Class 7         Class 8         Class
                                                                 -----------------------------------------------
Low Roof........................................................             104              80              66
Mid Roof........................................................             115              86              73
High Roof.......................................................             120              89              72
----------------------------------------------------------------------------------------------------------------
2017 Model Year and Later Gallons of Fuel per 1,000 Ton-Mile
----------------------------------------------------------------------------------------------------------------

[[Page 57213]]

 
                                                                              Day cab                 Sleeper cab
                                                                 -----------------------------------------------
                                                                          Class 7         Class 8         Class
                                                                 -----------------------------------------------
Low Roof........................................................            10.2             7.8             6.5
Mid Roof........................................................            11.3             8.4             7.2
High Roof.......................................................            11.8             8.7             7.1
----------------------------------------------------------------------------------------------------------------

    A summary of the final technology package costs is included in 
Table III-7 with additional details available in the RIA Chapter 2.
---------------------------------------------------------------------------

    \232\ Manufacturers may voluntarily opt-in to the NHTSA fuel 
consumption program in 2014 or 2015. If a manufacturer opts-in, the 
program becomes mandatory.

                 Table III-7--Class 7 and 8 Tractor Technology Costs Inclusive of Indirect Cost Markups in the 2014 Model Year a (2009$)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                        Class 7                                      Class 8
                                                              ------------------------------------------------------------------------------------------
                                                                        Day cab                   Day cab                       Sleeper cab
                                                              ------------------------------------------------------------------------------------------
                                                                 Low/mid                   Low/mid
                                                                   roof      High roof       roof      High roof     Low roof     Mid roof    High roof
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aerodynamics.................................................         $675         $924         $675         $924         $962         $983       $1,627
Steer Tires..................................................           68           68           68           68           68           68           68
Drive Tires..................................................           63           63          126          126          126          126          126
Weight Reduction.............................................        1,536        1,536        1,980        1,980        3,275        3,275        1,980
Idle Reduction with Auxiliary Power Unit.....................  ...........  ...........  ...........  ...........        3,819        3,819        3,819
Air Conditioning\c\..........................................           22           22           22           22           22           22           22
                                                              ------------------------------------------------------------------------------------------
    Total....................................................        2,364        2,612        2,871        3,119        8,271        8,291        7,641
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
\a\ Costs shown are for the 2014 model year so do not reflect learning impacts which would result in lower costs for later model years. For a
  description of the learning impacts considered in this analysis and how it impacts technology costs for other years, refer to Chapter 2 of the RIA
  (see RIA 2.2.2).
\b\ Note that values in this table include penetration rates. Therefore, the technology costs shown reflect the average cost expected for each of the
  indicated classes. To see the actual estimated technology costs exclusive of penetration rates, refer to Chapter 2 of the RIA (see RIA 2.9 in
  particular).
\c\ EPA's air conditioning standards are presented in Section II.E.5 above.

(v) Reasonableness of the Final Standards
    The final standards are based on aggressive application rates for 
control technologies which the agencies regard as the maximum feasible 
for purposes of EISA section 32902 (k) and appropriate under CAA 
section 202 (a) for the reasons given in Section (iii) above; see also 
RIA Chapter 2.5.8.2. These technologies, at the estimated application 
rates, are available within the lead time provided, as discussed in RIA 
Chapter 2.5. Use of these technologies would add only a small amount to 
the cost of the vehicle, and the associated reductions are highly cost 
effective, an estimated $20 per ton of CO2eq per vehicle in 
2030 without consideration of the substantial fuel savings.\233\ This 
is even more cost effective than the estimated cost effectiveness for 
CO2eq removal and fuel economy improvements under the light-
duty vehicle rule, already considered by the agencies to be a highly 
cost effective reduction.\234\ Moreover, the cost of controls is 
rapidly recovered due to the associated fuel savings, as shown in the 
payback analysis included in Table VIII-11 located in Section VIII 
below. Thus, overall cost per ton of the program, considering fuel 
savings, is negative--fuel savings associated with the rules more than 
offset projected costs by a wide margin. See Table VIII-6 in Section 
VIII below. Given that the standards are technically feasible within 
the lead time afforded by the 2014 model year, are inexpensive and 
highly cost effective even without accounting for the fuel savings, and 
have no apparent adverse potential impacts (e.g., there are no 
projected negative impacts on safety or vehicle utility), the final 
standards represent a reasonable choice under section 202(a) of the CAA 
and the maximum feasible under NHTSA's EISA authority at 49 U.S.C. 
32902(k)(2).
---------------------------------------------------------------------------

    \233\ See Section VIII.D below.
    \234\ The light-duty rule had an estimated cost per ton of $50 
when considering the vehicle program costs only and a cost of -$210 
per ton considering the vehicle program costs along with fuel 
savings in 2030. See 75 FR 25515, Table III.H.3-1.
---------------------------------------------------------------------------

(vi) Alternative Tractor Standards Considered
    The agencies are not adopting tractor standards less stringent than 
the proposed standards because the agencies believe these standards are 
appropriate, highly cost effective, and technologically feasible within 
the rulemaking time frame.
    The agencies considered adopting tractor standards which are more 
stringent than those proposed reflecting increased application rates of 
the technologies discussed. We also considered setting more stringent 
standards based on the inclusion of hybrid powertrains in tractors. We 
stopped short of finalizing more stringent standards based on higher 
application rates of improved aerodynamic controls and tire rolling 
resistance because we concluded that the technologies would not be 
compatible with the use profile of a subset of tractors which operate 
in off-

[[Page 57214]]

road conditions. We have not adopted more stringent standards for 
tractors based on the use of hybrid vehicle technologies, believing 
that additional development and therefore lead-time is needed to 
develop hybrid systems and battery technology for tractors that operate 
primarily in highway cruise operations. We know, for example, that 
hybrid systems are being researched to capture and return energy for 
tractors that operate in gently rolling hills. However, as discussed 
above, it is not clear to us today that these systems will be generally 
applicable to tractors in the time frame of this regulation. In 
addition, even if hybrid technologies were generally available for 
these tractors during the MY 2014-2017 period, their costs would be 
extremely high and benefits would be limited given that idle reduction 
controls already capture many of the same emissions. According to the 
2010 NAS Report, hybrid powertrains in tractors have the potential to 
improve fuel consumption by 10 percent, but it displaces the 6 percent 
reduction for idle reduction technologies, for a net improvement of 4 
percent at a cost of $25,000 per vehicle.\235\
---------------------------------------------------------------------------

    \235\ See 2010 NAS Report, Note 197, Page 146.
---------------------------------------------------------------------------

(b) Tractor Engines
(i) Baseline Engine Performance
    As noted above, EPA and NHTSA developed the baseline medium- and 
heavy heavy-duty diesel engine to represent a 2010 model year engine 
compliant with the 0.20 g/bhp-hr NOX standard for on-highway 
heavy-duty engines.
    The agencies developed baseline SET values for medium- and heavy 
heavy-duty diesel engines based on 2009 model year confidential 
manufacturer data and from testing conducted by EPA. The agencies 
adjusted the pre-2010 data to represent 2010 model year engine maps by 
using predefined technologies including SCR and other systems that are 
being used in current 2010 model year production. If an engine utilized 
did not meet the 0.20 g/bhp-hr NOX level, then the 
individual engine's CO2 result was adjusted to accommodate 
aftertreatment strategies that would result in a 0.20 g/bhp-hr 
NOX emission level as described in RIA Chapter 2.4.2.1. The 
engine CO2 results were then sales weighted within each 
regulatory subcategory (i.e., medium heavy-duty diesel or heavy heavy-
duty diesel) to develop an industry average 2010 model year reference 
engine. Although, most of the engines fell within a few percent of this 
baseline at least one engine was more than six percent above this 
average baseline.

     Table III-8--2010 Model Year Baseline Diesel Engine Performance
------------------------------------------------------------------------
                                                               Fuel
                                           CO2 Emissions    consumption
                                            (g/bhp-hr)      (gallon/100
                                                              bhp-hr)
------------------------------------------------------------------------
Medium Heavy-Duty Diesel--SET...........             518            5.09
Heavy Heavy-Duty Diesel--SET............             490            4.81
------------------------------------------------------------------------

(ii) Engine Technology Package Effectiveness
    The MHD and HHD diesel engine technology package for the 2014 model 
year includes engine friction reduction, improved aftertreatment 
effectiveness, improved combustion processes, and low temperature EGR 
system optimization. The agencies considered improvements in parasitic 
and friction losses through piston designs to reduce friction, improved 
lubrication, and improved water pump and oil pump designs to reduce 
parasitic losses. The aftertreatment improvements are available through 
lower backpressure of the systems and optimization of the engine-out 
NOX levels. Improvements to the EGR system and air flow 
through the intake and exhaust systems, along with turbochargers can 
also produce engine efficiency improvements. We note that individual 
technology improvements are not additive due to the interaction of 
technologies. The agencies assessed the impact of each technology over 
each of the 13 SET modes to project an overall weighted SET cycle 
improvement in the 2014 model year of 3 percent, as detailed in RIA 
Chapter 2.4.2.9 through 2.4.2.14. All of these technologies represent 
engine enhancements already developed beyond the research phase and are 
available as ``off the shelf'' technologies for manufacturers to add to 
their engines during the engine's next design cycle. We have estimated 
that manufacturers will be able to implement these technologies on or 
before the 2014 engine model year. The agencies adopted a standard that 
therefore reflects a 100 percent application rate of this technology 
package. The agencies gave consideration to finalizing a more stringent 
standard based on the application of mechanical turbocompounding by 
model year 2014, a mechanical means of waste heat recovery, but 
concluded that manufacturers would have insufficient lead-time to 
complete the necessary product development and validation work 
necessary to include this technology. Implementing turbocompounding 
into an engine design must be done through a significant redesign of 
the engine architecture a process that typically takes 4 to 5 years. 
Hence, we believe that turbocompounding is a more appropriate 
technology for the agencies to consider in the 2017 timeframe.
    As explained earlier, EPA's heavy-duty highway engine standards for 
criteria pollutants apply in three year increments. The heavy-duty 
engine manufacturer product plans have fallen into three year cycles to 
reflect these requirements. The agencies are finalizing fuel 
consumption and CO2 emission standards recognizing the 
opportunity for technology improvements over this time frame 
(specifically, the addition of turbocompounding to the engine 
technology package) while reflecting the typical heavy-duty engine 
manufacturer product plan redesign and refresh cycles. Thus, the 
agencies are finalizing a more stringent standard for heavy-duty 
engines beginning in the 2017 model year.
    The MHDD and HHDD engine technology package for the 2017 model year 
includes the continued development of the 2014 model year technology 
package including refinement of the aftertreatment system plus 
turbocompounding. The agencies calculated overall reductions in the 
same manner as for the 2014 model year package. The weighted SET cycle 
improvements lead to a 6 percent reduction on the SET cycle, as 
detailed

[[Page 57215]]

in RIA Chapter 2.4.2.12. The agencies' final standards are premised on 
a 100 percent application rate of this technology package.
    Commenters noted that the National Academy of Sciences (NAS) study 
indicates that additional technology improvements can be made to heavy-
duty engines in MY 2014 and 2017. For diesel engine standards, the 
agencies evaluated the following technologies: Combustion system 
optimization, turbocharging and air handling systems, engine parasitic 
and friction reduction, integrated aftertreatment systems, 
electrification, and waste heat recovery.
    The agencies carefully evaluated the research supporting the NAS 
report and its recommendations and incorporated them to the extent 
practicable in the development of the HD program. While the NAS report 
suggests that greater engine improvements could be achieved by the use 
of technologies such as improved emission control systems and 
turbocompounding than do the agencies in this final action, we believe 
the standards being finalized represent the most stringent technically 
feasible for diesel engines used in tractors and vocational vehicles in 
the 2014 to 2017 model year time frame. The NAS study concluded that 
tractor engine fuel consumption can be reduced by approximately 15 
percent in the 2015 to 2020 time frame and vocational engine fuel 
consumption can be reduced by approximately 10 to 17 percent in the 
same time frame compared to a 2008 engine baseline.\236\ Throughout 
this presentation, the agencies' projections of performance 
improvements are measured relative to a 2010 engine performance 
baseline that itself reflects a four to five percent improvement over 
the 2008 engine baseline used by NAS. Based on a review of existing 
studies, NAS study authors found a range of reduction potential exists 
for improvements in combustion efficiency, electrification of 
accessories; improved emission control systems; and turbocompounding. 
The study found that improvements in combustion efficiency can provide 
reductions of 1 percent to 4 percent; electrification of accessories 
can provide reductions of 2 percent to 5 percent in a hybridized 
vehicle; improved emission control systems can provide a 1 percent to 4 
percent improvement (depending on whether the improvement is to the EGR 
or SCR system); and a 2.5 percent to 10 percent reduction is possible 
with mechanical or electrical turbocompounding. While the reductions 
being finalized in this regulation are lower than those published in 
the NAS study, the agencies believe that the percent reductions being 
finalized in these rules are consistent with the findings of the NAS 
study. The reasons for this are as follows.
---------------------------------------------------------------------------

    \236\ National Research Council, ``Technologies and Approaches 
to Reducing the Fuel Consumption of Medium- and Heavy-Duty 
Vehicles'' Figure S-1, page 4, National Acedemies Press, 2011.
---------------------------------------------------------------------------

    First, some technologies cannot be used by all manufacturers. For 
example, improved SCR conversion efficiency was projected by NAS to 
provide a 3 percent to 4 percent improvement in fuel consumption. 
Conversely, low temperature EGR was found to provide only a one percent 
improvement. While the majority of manufacturers do use SCR systems and 
will be able to realize the 3 percent to 4 percent improvement, not all 
manufacturers use SCR for NOX aftertreatment. Manufacturers 
that do not use SCR aftertreatment systems would only be able to 
realize the 1 percent improvement from low temperature EGR. The 
agencies need to take into consideration the entire market in setting 
the stringency of the standards and, in assessing feasibility and cost, 
cannot assume that all manufacturers will be able to use all 
technologies.
    Second, significant technical advances may be needed in order to 
realize the upper end of estimates for some technologies. For example, 
studies evaluated by NAS on turbocompounding found that a 2.5 percent 
to 10 percent reduction is feasible. However, only one system is 
available commercially and this system provides reductions on the low 
end of this range.\237\ Little technical information is available on 
the systems that achieve reductions in the upper range for 
turbocompounding. These systems are based on proprietary designs the 
improvement results for which have not yet been replicated by other 
companies or organizations. The agencies are assuming that all tractor 
engine manufacturers will use turbocompounding by 2017 model year. This 
will require a significant change in the design of heavy-duty tractor 
engines, one that represents the maximum technically feasible standard 
even at the low end of the assumed improvement spectrum.
---------------------------------------------------------------------------

    \237\ NAS 2010, page 53 cites Detroit Diesel Corporation, DD15 
Brochure, DDC-EMC-BRO-0003-0408, April 2008.
---------------------------------------------------------------------------

    Finally, different duty cycles used in the evaluation of medium- 
and heavy-duty engine technologies can affect reported fuel consumption 
improvements. For example, some technologies are dependent on high load 
conditions to provide the greatest reductions. The duty cycles used to 
evaluate some of the technologies considered by NAS differed 
significantly from that used by the agencies in the modeling for this 
rulemaking. Maximum and average speed was higher in some of the cycles 
used in the studies, for example, and one result was demonstrated on a 
nonroad engine cycle. In another example, the effectiveness of 
turbocompounding when evaluated on a duty cycle with higher engine load 
can show a greater reduction potential than when evaluated with a lower 
engine load. In addition, technologies such as improvements to cooling 
fans, air compressors, and air conditioning systems will not be 
demonstrated using the engine dynamometer test procedures being adopted 
in this final action because those components are not installed on the 
engine during the testing. The agencies selected the duty cycles for 
analysis, and for the final standards, that we believed best suited 
tractor engines.
    The agencies selected engine technologies and the estimated fuel 
reduction percentages for setting the standards. For the reasons stated 
above, the agencies believe the technologies and required improvements 
in fuel consumption represent the maximum feasible improvement, and are 
appropriate, cost-effective, and technologically feasible.
    We gave consideration to finalizing an even more stringent standard 
based on the use of waste heat recovery via a Rankine cycle (also 
called bottoming cycle) but concluded that there is insufficient lead-
time between now and 2017 for this promising technology to be developed 
and applied generally to all heavy-duty engines. TIAX noted in their 
report to the NAS committee that the engine improvements beyond 2015 
model year included in their report are highly uncertain, though they 
include Rankine cycle type waste heat recovery as applicable sometime 
between 2016 and 2020.\238\ The Department of Energy is working with 
industry to develop waste heat recovery systems for heavy-duty engines. 
At the Diesel Engine-Efficiency and Emissions Research (DEER) 
conference in 2010, Caterpillar presented details regarding their waste 
heat recovery systems development effort. In their presentation, 
Caterpillar clearly noted that the work is a research project and 
therefore does not imply

[[Page 57216]]

commercial viability.\239\ At the same conference, Concepts NREC 
presented a status of exhaust energy recovery in heavy-duty engines. 
The scope of Concepts NREC included the design and development of 
prototype parts.\240\ Cummins, also in coordination with DOE, is also 
active in developing exhaust energy recovery systems. Cummins made a 
presentation to the DEER conference in 2009 providing an update on 
their progress which highlighted opportunities to achieve a 10 percent 
engine efficiency improvement during their research, but indicated the 
need to focus their future development on areas with the highest 
recovery opportunities (such as EGR, exhaust, and charge air).\241\ 
Cummins also indicated that future development would focus on reducing 
the high additional costs and system complexity. Based upon the 
assessment of this information, the agencies did not include these 
technologies in determining the stringency of the final standards. 
However, we do believe the bottoming cycle approach represents a 
significant opportunity to reduce fuel consumption and GHG emissions in 
the future. EPA and NHTSA are therefore both finalizing provisions for 
advanced technology credits described in Section IV to create 
incentives for manufacturers to continue to invest to develop this 
technology.
---------------------------------------------------------------------------

    \238\ See TIAX, Note 198, Page 4-29.
    \239\ Kruiswyk, R. ``An Engine System Approach to Exhaust Waste 
Heat Recovery.'' Presented at DOE DEER Conference on September 29, 
2010. Last viewed on May 11, 2011 at http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2010/wednesday/presentations/deer10_kruiswyk.pdf.
    \240\ Cooper, D, N. Baines, N. Sharp. ``Organic Rankine Cycle 
Turbine for Exhaust Energy Recovery in a Heavy Truck Engine.'' 
Presented at the 2010 DEER Conference. Last viewed on May 11, 2011 
at http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2010/wednesday/presentations/deer10_baines.pdf.
    \241\ Nelson, C. ``Exhaust Energy Recovery.'' Presented at the 
DOE DEER Conference on August 5, 2009. Last viewed on May 11, 2011 
at http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2009/session5/deer09_nelson_1.pdf.
---------------------------------------------------------------------------

(iii) Derivation of Engine Standards
    EPA developed the final 2014 model year CO2 emissions 
standards (based on the SET cycle) for diesel engines by applying the 
three percent reduction from the technology package (just explained 
above) to the 2010 model year baseline values determined using the SET 
cycle. EPA developed the 2017 model year CO2 emissions 
standards for diesel engines while NHTSA similarly developed the 2017 
model year diesel engine fuel consumption standards by applying the 6 
percent reduction from the 2017 model year technology package 
(reflecting performance of turbocompounding plus the 2014 MY technology 
package) to the 2010 model year baseline values. The final standards 
are included in Table III-9.

                          Table III-9--Final Diesel Engine Standards Over the SET Cycle
----------------------------------------------------------------------------------------------------------------
                                                                                    MHD diesel      HHD diesel
                  Model year                                                          engine          engine
----------------------------------------------------------------------------------------------------------------
2014-2016.....................................  CO2 Standard (g/bhp-hr).........             502             475
                                                Voluntary Fuel Consumption                  4.93            4.67
                                                 Standard (gallon/100 bhp-hr).
2017 and later................................  CO2 Standard (g/bhp-hr).........             487             460
                                                Fuel Consumption (gallon/100 bhp-           4.78            4.52
                                                 hr).
----------------------------------------------------------------------------------------------------------------

(iv) Engine Technology Package Costs
    EPA has historically used two different approaches to estimate the 
indirect costs (sometimes called fixed costs) of regulations including 
costs for product development, machine tooling, new capital investments 
and other general forms of overhead that do not change with incremental 
changes in manufacturing volumes. Where the Agency could reasonably 
make a specific estimate of individual components of these indirect 
costs, EPA has done so. Where EPA could not readily make such an 
estimate, EPA has instead relied on the use of markup factors referred 
to as indirect cost multipliers (ICMs) to estimate these indirect costs 
as a ratio of direct manufacturing costs. In general, EPA has used 
whichever approach it believed could provide the most accurate 
assessment of cost on a case-by-case basis. The agencies' general 
approach used elsewhere in this action (for HD pickup trucks, gasoline 
engines, combination tractors, and vocational vehicles) estimates 
indirect costs based on the use of ICMs. See also 75 FR 25376. We have 
used this approach generally because these standards are based on 
installing new parts and systems purchased from a supplier. In such a 
case, the supplier is conducting the bulk of the research and 
development on the new parts and systems and including those costs in 
the purchase price paid by the original equipment manufacturer. In this 
situation, we believe that the ICM approach provides an accurate and 
clear estimate of the additional indirect costs borne by the 
manufacturer.
    For the heavy-duty diesel engine segment, however, the agencies do 
not consider this model to be the most appropriate because the primary 
cost is not expected to be the purchase of parts or systems from 
suppliers or even the production of the parts and systems, but rather 
the development of the new technology by the original equipment 
manufacturer itself. Most of the technologies the agencies are 
projecting the heavy-duty engine manufacturers will use for compliance 
reflect modifications to existing engine systems rather than wholesale 
addition of technology (e.g., improved turbochargers rather than adding 
a turbocharger where it did not exist before as was done in our light-
duty joint rulemaking in the case of turbo-downsizing). When the bulk 
of the costs come from refining an existing technology rather than a 
wholesale addition of technology, a specific estimate of indirect costs 
may be more appropriate. For example, combustion optimization may 
significantly reduce emissions and cost a manufacturer millions of 
dollars to develop but will lead to an engine that is no more expensive 
to produce. Using a bill of materials approach would suggest that the 
cost of the emissions control was zero reflecting no new hardware and 
ignoring the millions of dollars spent to develop the improved 
combustion system. Details of the cost analysis are included in the RIA 
Chapter 2. The agencies did not receive any comments regarding the cost 
approach used in the proposal.
    The agencies developed the engineering costs for the research and 
development of diesel engines with lower fuel consumption and 
CO2 emissions. The aggregate costs for engineering hours, 
technician support,

[[Page 57217]]

dynamometer cell time, and fabrication of prototype parts are estimated 
at $6.8 million (2009 dollars) per manufacturer per year over the five 
years covering 2012 through 2016. In aggregate, this averages out to 
$284 per engine during 2012 through 2016 using an annual sales volume 
of 600,000 light-, medium- and heavy-HD engines. The agencies received 
comments from Horriba regarding the assumption the agencies used in the 
proposal that said manufacturers would need to purchase new equipment 
for measuring N2O and the associated costs. Horriba provided 
information regarding the cost of stand-alone FTIR instrumentation 
(estimated at $50,000 per unit) and cost of upgrading existing emission 
measurement systems with NDIR analyzers (estimated at $25,000 per 
unit). The agencies further analyzed our assumptions along with 
Horriba's comments. Thus, we have revised the equipment costs estimates 
and assumed that 75 percent of manufacturers would update existing 
equipment while the other 25 percent would require new equipment. The 
agencies are estimating costs of $63,087 (2009 dollars) per engine 
manufacturer per engine subcategory (light-, medium- and heavy-HD) to 
cover the cost of purchasing photo-acoustic measurement equipment for 
two engine test cells. This would be a one-time cost incurred in the 
year prior to implementation of the standard (i.e., the cost would be 
incurred in 2013). In aggregate, this averages out to less than $1 per 
engine in 2013 using an annual sales volume of 600,000 light-, medium- 
and heavy-HD engines.
    Where we projected that additional new hardware was needed to the 
meet the final standards, we developed the incremental costs for those 
technologies and marked them up using the ICM approach. Table III-10 
below summarizes those estimates of cost on a per item basis. All costs 
shown in Table III-18, below, include a low complexity ICM of 1.15 and 
flat-portion of the curve learning is considered applicable to each 
technology.

 Table III-10--Heavy-Duty Diesel Engine Component Costs for Combination
                           Tractors\a\ (2009$)
------------------------------------------------------------------------
               Technology                      2014            2017
------------------------------------------------------------------------
Cylinder Head...........................              $6              $6
Turbo efficiency........................              18              17
EGR cooler..............................               4               3
Water pump..............................              91              84
Oil pump................................               5               4
Fuel pump...............................               5               4
Fuel rail...............................              10               9
Fuel injector...........................              11              10
Piston..................................               3               3
Engine Friction Reduction of Valvetrain.              82              76
Turbo-compounding (engines placed in                   0             875
 combination tractors only).............
MHHD and HHDD Total (combination                     234           1,091
 tractors)..............................
------------------------------------------------------------------------
Note:
\a\ Costs for aftertreatment improvements for MH and HH diesel engines
  are covered via the engineering costs (see text). For LH diesel
  engines, we have included the cost of aftertreatment improvements as a
  technology cost.

    The overall diesel engine technology package cost for an engine 
being placed in a combination tractor is $234 in the 2014 model year 
and $1,091 in the 2017 model year.
(v) Reasonableness of the Final Standards
    The final engine standards appear to be reasonable and consistent 
with the agencies' respective statutory authorities. With respect to 
the 2014 and 2017 MY standards, all of the technologies on which the 
standards are predicated have already been demonstrated in some 
capacity and their effectiveness is well documented. The final 
standards reflect a 100 percent application rate for these 
technologies. The costs of adding these technologies remain modest 
across the various engine classes as shown in Table III-10. Use of 
these technologies would add only a small amount to the cost of the 
vehicle,\242\ and the associated reductions are highly cost effective, 
an estimated $20 per ton of CO2eq per vehicle.\243\ This is 
even more cost effective than the estimated cost effectiveness for 
CO2eq removal under the light-duty vehicle rule, already 
considered by the agencies to be a highly cost effective 
reduction.\244\ Even the more expensive 2017 MY final standard still 
represents only a small fraction of the vehicle's total cost and is 
even more cost effective than the light-duty vehicle rule. Moreover, 
costs are more than offset by fuel savings. Accordingly, EPA and NHTSA 
view these standards as reflecting an appropriate balance of the 
various statutory factors under section 202(a) of the CAA and under 
NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).
---------------------------------------------------------------------------

    \242\ Sample 2010 MY day cabs are priced at $89,000 while 2010 
MY sleeper cabs are priced at $113,000. See page 3 of ICF's 
``Investigation of Costs for Strategies to Reduce Greenhouse Gas 
Emissions for Heavy-Duty On-Road Vehicles.'' July 2010.
    \243\ See Tractor CO2 savings and technology costs in 
Table 7-5 in RIA chapter 7.
    \244\ The light-duty rule had an estimated cost per ton of $50 
when considering the vehicle program costs only and a cost of -$210 
per ton considering the vehicle program costs along with fuel 
savings in 2030. See 75 FR 25515, Table III.H.3-1.
---------------------------------------------------------------------------

(vi) Temporary Alternative Standard for Certain Engine Families
    As discussed above in Section II.B(2)(b), notwithstanding the 
general reasonableness of the final standards, the agencies recognize 
that heavy-duty engines have never been subject to GHG or fuel 
consumption (or fuel economy) standards and that such control has not 
necessarily been an independent priority for manufacturers. The result 
is that there are a group of legacy engines with emissions higher than 
the industry baseline for which compliance with the final 2014 MY 
standards may be more challenging and for which there may simply be 
inadequate lead time. The issue is not whether these engines' GHG and 
fuel consumption performance cannot be improved by utilizing the 
technology packages on which the final standards are based. Those 
technologies can be utilized by all diesel engines installed in 
tractors and the same degree of reductions obtained. Rather the 
underlying base engine components of these engines reflect designs that 
are decades old and therefore have base performance levels below what 
is typical for the industry as a whole

[[Page 57218]]

today. Manufacturers have been gradually replacing these legacy 
products with new engines. Engine manufacturers have indicated to the 
agencies they will have to align their planned replacement of these 
products with our final standards and at the same time add additional 
technologies beyond those identified by the agencies as the basis for 
the final standard. Because these changes will reflect a larger degree 
of overall engine redesign, manufacturers may not be able to complete 
this work for all of their legacy products prior to model year 2014. To 
pull ahead these already planned engine replacements would be 
impossible as a practical matter given the engineering structure and 
lead-times inherent in the companies' existing product development 
processes. We have also concluded that the use of fleet averaging would 
not address the issue of legacy engines because each manufacturer 
typically produces only a limited line of MHDD and HHDD engines. 
Because there are ample fleetwide averaging opportunities for heavy-
duty pickups and vans, the agencies do not perceive similar 
difficulties for these vehicles.
    Facing a similar issue in the light-duty vehicle rule, EPA adopted 
a Temporary Lead Time Allowance provision whereby a limited number of 
vehicles of a subset of manufacturers would meet an alternative 
standard in the early years of the program, affording them sufficient 
lead time to meet the more stringent standards applicable in later 
model years. See 75 FR 25414-25418. The agencies are finalizing a 
similar approach here. As explained above in Section II.B.(2)(b), the 
agencies are finalizing a regulatory alternative whereby a 
manufacturer, for a limited period, would have the option to comply 
with a unique standard requiring the same level of reduction of 
emissions (i.e., percent removal) and fuel consumption as otherwise 
required, but the reduction would be measured from its own 2011 model 
year baseline. We are thus finalizing an optional standard whereby 
manufacturers would elect to have designated engine families meet a 
standard of 3 percent reduction from their 2011 baseline emission and 
fuel consumption levels for that engine family or engine subcategory. 
Our assessment is that this three percent reduction is appropriate 
based on use of similar technology packages at similar cost as we have 
estimated for the primary program. In the NPRM, we solicited comment on 
extending this alternative (See 75 FR at 74202). As explained earlier, 
we have decided not to allow the alternative standard to continue past 
the 2016 MY. By this time, the engines should have gone through a 
redesign cycle which will allow manufacturers to replace those legacy 
engines which resulted in abnormally high baseline emission and fuel 
consumption levels and to achieve the MY 2017 standards which would be 
feasible using the technology package set out above (optimized 
NOX aftertreatment, improved EGR, reductions in parasitic 
losses, and turbocharging). Manufacturers would, of course, be free to 
adopt other technology paths which meet the final MY 2017 standards.
    Since the alternative standard is premised on the need for 
additional lead time, manufacturers would first have to utilize all 
available flexibilities which could otherwise provide that lead time. 
Thus, as proposed, the alternative would not be available unless and 
until a manufacturer had exhausted all available credits and credit 
opportunities, and engines under the alternative standard could not 
generate credits. See also 75 FR 25417-25419 (similar approach for 
vehicles which are part of Temporary Lead Time Allowance under the 
light-duty vehicle rule). We are finalizing that manufacturers can 
select engine families for this alternative standard without agency 
approval, but are requiring that manufacturers notify the agency of 
their choice and also requiring manufacturers to include in that 
notification a demonstration that it has exhausted all available 
credits and credit opportunities. Manufacturers would also have to 
demonstrate their 2011 baseline calculations as part of the 
certification process for each engine family for which the manufacturer 
elects to use the alternative standard. See Section V.C.1(b)(i) below.
(vii) ther Engine Standards Considered
    The agencies are not finalizing engine standards less stringent 
than the final standards because the agencies believe these final 
standards are appropriate, highly cost effective, and technologically 
feasible, as just described.
    The agencies considered finalizing engine standards which are more 
stringent. Since the final standards reflect 100 percent utilization of 
the various technology packages, some additional technology would have 
to be added. The agencies are finalizing 2017 model year standards 
based on the use of turbocompounding. As discussed above in Section 
III.A.2.b.iii, the agencies considered the inclusion of more advanced 
heat recovery systems, such as Rankine or bottoming cycles, which would 
provide further reductions. However, the agencies are not finalizing 
this level of stringency because our assessment is that these 
technologies would not be available for production by the 2017 model 
year.

B. Heavy-Duty Pickup Trucks and Vans

    This section describes the process the agencies used to develop the 
standards the agencies are finalizing for HD pickups and vans. We 
started by gathering available information about the fuel consumption 
and CO2 emissions from recent model year vehicles. The core 
portion of this information comes primarily from EPA's certification 
databases, CFEIS and Verify, which contain the publicly available data 
\245\ regarding emission and fuel economy results. This information is 
not extensive because manufacturers have not been required to chassis 
test HD diesel vehicles for EPA's criteria pollutant emissions 
standards, nor have they been required to conduct any testing of heavy-
duty vehicles on the highway cycle. Nevertheless, enough certification 
activity has occurred for diesels under EPA's optional chassis-based 
program, and, due to a California NOX requirement for the 
highway test cycle, enough test results have been voluntarily reported 
for both diesel and gasoline vehicles using the highway test cycle, to 
yield a reasonably robust data set. To supplement this data set, for 
purposes of this rulemaking EPA initiated its own testing program using 
in-use vehicles. This program and the results from it thus far are 
described in a memorandum to the docket for this rulemaking.\246\
---------------------------------------------------------------------------

    \245\ http://www.epa.gov/otaq/certdata.htm.
    \246\ Memorandum from Cleophas Jackson, U.S.EPA, to docket EPA-
HQ-OAR-2010-0162, ``Heavy-Duty Greenhouse Gas and Fuel Consumption 
Test Program Summary'', September 20, 2010.
---------------------------------------------------------------------------

    Heavy-duty pickup trucks and vans are sold in a variety of 
configurations to meet market demands. Among the differences in these 
configurations that affect CO2 emissions and fuel 
consumption are curb weight, GVWR, axle ratio, and drive wheels (two-
wheel drive or four-wheel drive). Because the currently-available test 
data set does not capture all of these configurations, it is necessary 
to extend that data set across the product mix using adjustment 
factors. In this way a test result from, say a truck with two-wheel 
drive, 3.73:1 axle ratio, and 8000 lb test weight, can be used to model 
emissions and fuel consumption from a truck of the same basic body 
design, but with four-wheel drive, a 4.10:1 axle ratio, and 8,500 lb 
test weight. The adjustment factors are

[[Page 57219]]

based on data from testing in which only the parameters of interest are 
varied. These parameterized adjustments and their basis are also 
described in a memorandum to the docket for this rulemaking.\247\
---------------------------------------------------------------------------

    \247\ Memorandum from Anthony Neam and Jeff Cherry, U.S.EPA, to 
docket EPA-HQ-OAR-2010-0162, October 18, 2010.
---------------------------------------------------------------------------

    The agencies requested and received from each of the three major 
manufacturers confidential information for each model and 
configuration, indicating the values of each of these key parameters as 
well as the annual production (for the U.S. market). Production figures 
are useful because, under our final standards for HD pickups and vans, 
compliance is judged on the basis of production-weighted (corporate 
average) emissions or fuel consumption level, not individual vehicle 
levels. For consistency and to avoid confounding the analysis with data 
from unusual market conditions in 2009, the production and vehicle 
specification data is from the 2008 model year. We made the simplifying 
assumption that these sales figures reasonably approximate future sales 
for purposes of this analysis.
    One additional assessment was needed to make the data set useful as 
a baseline for the standards selection. Because the appropriate 
standards are determined by applying efficiency-improving technologies 
to the baseline fleet, it is necessary to know the level of penetration 
of these technologies in the latest model year (2010). This information 
was also provided confidentially by the manufacturers. Generally, the 
agencies found that the HD pickup and van fleet was at a roughly 
consistent level of technology application, with (1) the transition 
from 4-speed to 5- or 6-speed automatic transmissions mostly 
accomplished, (2) coupled cam phasing to achieve variable valve control 
on gasoline engines likewise mostly in place,\248\ and (3) substantial 
remaining potential for optimizing catalytic diesel NOX 
aftertreatment to improve fuel economy (the new heavy-duty 
NOX standards having taken effect in the 2010 model year).
---------------------------------------------------------------------------

    \248\ See Section III.B(2)(a) for our response to comments 
arguing for inclusion of this technology in the list of technologies 
needed to meet the standards.
---------------------------------------------------------------------------

    Taking this 2010 baseline fleet, and applying the technologies 
determined to be feasible and appropriate by the 2018 model year, along 
with their effectiveness levels, the agencies could then make a 
determination of appropriate final standards. The assessment of 
feasibility, described immediately below, takes into account the 
projected costs of these technologies. The derivation of these costs, 
largely based on analyses developed in the light-duty GHG and fuel 
economy rulemaking, are described in Section III.B(3).
    Our assessment concluded that the technologies that the agencies 
considered feasible and appropriate for HD pickups and vans could be 
consistently applied to essentially all vehicles across this sector by 
the 2018 model year. Therefore we did not apply varying penetration 
rates across vehicle types and models in developing and evaluating the 
final standards.
    Since the manufacturers of HD pickups and vans generally only have 
one basic pickup truck and van with different versions (i.e., different 
wheel bases, cab sizes, two-wheel drive, four-wheel drive, etc.) and do 
not have the flexibility of the light-duty fleet to coordinate model 
improvements over several years, changes to the HD pickups and vans to 
meet new standards must be carefully planned with the redesign cycle 
taken into account. The opportunities for large-scale changes (e.g., 
new engines, transmission, vehicle body and mass) thus occur less 
frequently than in the light-duty fleet, typically at spans of 8 or 
more years. However, opportunities for gradual improvements not 
necessarily linked to large scale changes can occur between the 
redesign cycles. Examples of such improvements are upgrades to an 
existing vehicle model's engine, transmission and aftertreatment 
systems. Given this long redesign cycle and our understanding with 
respect to where the different manufacturers are in that cycle, the 
agencies have initially determined that the full implementation of the 
final standards would be feasible and appropriate by the 2018 model 
year.
    Although we did not determine a technological need for less than 
full implementation of any technology, we did decide that a phased 
implementation schedule would be appropriate to accommodate 
manufacturers' redesign workload and product schedules, especially in 
light of this sector's relatively low sales volumes and long product 
cycles. We did not determine a specific cost of implementing the final 
standards immediately in 2014 without a phase-in, but we assessed it to 
be much higher than the cost of the phase-in we are finalizing, due to 
the workload and product cycle disruptions it would cause, and also due 
to manufacturers' resulting need to develop some of these technologies 
for heavy-duty applications sooner than or simultaneously with light-
duty development efforts. See generally 75 FR 25467-25468 explaining 
why attempting major changes outside the redesign cycle period raises 
very significant issues of both feasibility and cost. On the other 
hand, waiting until 2018 before applying any new standards could miss 
the opportunity to achieve meaningful and cost-effective early 
reductions not requiring a major product redesign.
    The final phase-in schedule, 15-20-40-60-100 percent in 2014-2015-
2016-2017-2018, respectively, was chosen to strike a balance between 
meaningful reductions in the early years (reflecting the technologies' 
penetration rates of 15 and 20 percent) and providing manufacturers 
with needed lead time via a gradually accelerating ramp-up of 
technology penetration.\249\ By expressing the final phase-in in terms 
of increasing fleetwide stringency for each manufacturer, while also 
providing for credit generation and use (including averaging, carry-
forward, and carry-back), we believe our program affords manufacturers 
substantial flexibility to satisfy the phase-in through a variety of 
pathways, among them, the gradual application of technologies across 
the fleet (averaging a fifth of total production in each year), greater 
application levels on only a portion of the fleet, or a mix of the two.
---------------------------------------------------------------------------

    \249\ The NHTSA program provides voluntary standards for model 
years 2014 and 2015. NHTSA and EPA are also providing an alternative 
standards phase-in that meets EISA's requirement for three years of 
regulatory stability. See Section II.C.d.ii for a more detailed 
discussion.
---------------------------------------------------------------------------

    We considered setting more stringent standards that would require 
the application of additional technologies by 2018. We expect, in fact, 
that some of these technologies may well prove feasible and cost-
effective in this time frame, and may even become technologies of 
choice for individual manufacturers. This dynamic has played out in EPA 
programs before and highlights the value of setting performance-based 
standards that leave engineers the freedom to find the most cost-
effective solutions.
    However, the agencies do believe that at this stage there is not 
enough information to conclude that the additional technologies provide 
an appropriate basis for standard-setting. For example, we believe that 
42V stop-start systems can be applied to gasoline vehicles with 
significant GHG and fuel consumption benefits, but we recognize that 
there is uncertainty at this time over the cost-effectiveness of these 
systems in heavy-duty applications, and legitimate concern with 
customer

[[Page 57220]]

acceptance of vehicles with high GCWR towing large loads that would 
routinely stop running at idle. Hybrid electric technology likewise 
could be applied to heavy-duty vehicles, and in fact has already been 
so applied on a limited basis. However, the development, design, and 
tooling effort needed to apply this technology to a vehicle model is 
quite large, and seems less likely to prove cost-effective in this time 
frame, due to the small sales volumes relative to the light-duty 
sector. Here again, potential customer acceptance would need to be 
better understood because the smaller engines that facilitate much of a 
hybrid's benefit are typically at odds with the importance pickup 
trucks buyers place on engine horsepower and torque, whatever the 
vehicle's real performance.
    We also considered setting less stringent standards calling for a 
more limited set of applied technologies. However, our assessment 
concluded with a high degree of confidence that the technologies on 
which the final standards are premised are clearly available at 
reasonable cost in the 2014-2018 time frame, and that the phase-in and 
other flexibility provisions allow for their application in a very 
cost-effective manner, as discussed in this section below.
    More difficult to characterize is the degree to which more or less 
stringent standards might be appropriate because of under- or over-
estimating effectiveness of the technologies whose performance is the 
basis of the final standards. Our basis for these estimates is 
described in the following Section 0. Because for the most part these 
technologies have not yet been applied to HD pickups and vans, even on 
a limited basis, we are relying to some degree on engineering judgment 
in predicting their effectiveness. Even so, we believe that we have 
applied this judgment using the best information available, primarily 
from our recent rulemaking on light-duty vehicle GHGs and fuel economy, 
and have generated a robust set of effectiveness values.
(1) What technologies did the agencies consider?
    The agencies considered over 35 vehicle technologies that 
manufacturers could use to improve the fuel consumption and reduce 
CO2 emissions of their vehicles during MYs 2014-2018. The 
majority of the technologies described in this section is readily 
available, well known, and could be incorporated into vehicles once 
production decisions are made. Several of the technologies have already 
been introduced into the heavy-duty pickup and van market (i.e., 
variable valve timing, improved accessories, etc.) in a limited number 
of applications. Other technologies considered may not currently be in 
production, but are beyond the research phase and under development, 
and are expected to be in production in highway vehicles over the next 
few years. These are technologies which are capable of achieving 
significant improvements in fuel economy and reductions in 
CO2 emissions, at reasonable costs. The agencies did not 
consider technologies in the research stage because there is 
insufficient time for such technologies to move from research to 
production during the model years covered by this final action.
    The agencies received comments regarding applicability of certain 
advanced technologies described in the TIAX 2009 report submitted to 
NAS. Specifically mentioned were turbocharging and downsizing of 
gasoline vehicles and hydraulic hybrid systems. While turbocharging and 
downsizing of gasoline vehicles was a principal technology underlying 
the standards in the light-duty rule, the agencies determined that in 
the realm of heavy-duty vehicles, this approach provides much less 
benefit to vehicles which are required to regularly operate at high and 
sustained loads. In light-duty applications, downsizing of a typically 
oversized engine largely results in benefits mainly under partial and 
light load conditions. This approach is more applicable to light-duty 
vehicles because they infrequently require high or full power. Further, 
while turbo downsizing was already occurring in a portion of the light-
duty fleet, it has not been demonstrated in the heavy-duty fleet, 
likely due to concerns with durability of this technology in the 
sustained high-load duty cycles frequently encountered. Similarly, 
other light-duty technologies (i.e., cylinder deactivation, engine 
start stop) were also determined to not be compatible with the duty 
cycle of heavy-duty vehicles for similar reasons. Due to the relatively 
aggressive implementation of this program and the lack of 
commercialization in the heavy-duty market, hydraulic hybrid systems 
were not considered a technology that could be implemented in the time 
frame of this program for the HD pickup and van sector. The fact that 
no HD pickup or van hydraulic hybrids have been, or are the verge of 
being marketed makes their widespread introduction before the MY 2018 
final year of the phase-in very unlikely.
    The technologies considered in the agencies' analysis are briefly 
described below. They fall into five broad categories: engine 
technologies, transmission technologies, vehicle technologies, 
electrification/accessory technologies, and hybrid technologies.
    In this class of trucks and vans, diesel engines are installed in 
about half of all vehicles. The ratio between gasoline and diesel 
engine purchases by consumers has tended to track changes in the 
overall cost of oil and the relative cost of gasoline and diesel fuels. 
When oil prices are higher, diesel sales tend to increase. This trend 
has reversed when oil prices fall or when diesel fuel prices are 
significantly higher than gasoline. In the context of our technology 
discussion for heavy-duty pickups and vans, we are treating gasoline 
and diesel engines separately so each has a set of baseline 
technologies. We discuss performance improvements in terms of changes 
to those baseline engines. Our cost and inventory estimates contained 
elsewhere reflect the current fleet baseline with an appropriate mix of 
gasoline and diesel engines. Note that we are not basing the final 
standards on a targeted switch in the mix of diesel and gasoline 
vehicles. We believe our final standards require similar levels of 
technology development and cost for both diesel and gasoline vehicles. 
Hence the final program does not force, nor does it discourage, changes 
in a manufacturer's fleet mix between gasoline and diesel vehicles. 
Although we considered setting a single standard based on the 
performance level possible for diesel vehicles, we are not finalizing 
such an approach because the potential disruption in the HD pickup and 
van market from a forced shift would not be justified. Types of engine 
technologies that improve fuel efficiency and reduce CO2 
emissions include the following:
     Low-friction lubricants--low viscosity and advanced low 
friction lubricants oils are now available with improved performance 
and better lubrication. If manufacturers choose to make use of these 
lubricants, they would need to make engine changes and possibly conduct 
durability testing to accommodate the low-friction lubricants.
     Reduction of engine friction losses--can be achieved 
through low-tension piston rings, roller cam followers, improved 
material coatings, more optimal thermal management, piston surface 
treatments, and other improvements in the design of engine components 
and subsystems that improve engine operation.
     Cylinder deactivation--deactivates the intake and exhaust 
valves and prevents fuel injection into some cylinders during light-
load operation.

[[Page 57221]]

The engine runs temporarily as though it were a smaller engine which 
substantially reduces pumping losses.
     Variable valve timing--alters the timing of the intake 
valve, exhaust valve, or both, primarily to reduce pumping losses, 
increase specific power, and control residual gases.
     Stoichiometric gasoline direct-injection technology--
injects fuel at high pressure directly into the combustion chamber to 
improve cooling of the air/fuel charge within the cylinder, which 
allows for higher compression ratios and increased thermodynamic 
efficiency.
     Diesel engine improvements and diesel aftertreatment 
improvements--improved EGR systems and advanced timing can provide more 
efficient combustion and, hence, lower fuel consumption. Aftertreatment 
systems are a relatively new technology on diesel vehicles and, as 
such, improvements are expected in coming years that allow the 
effectiveness of these systems to improve while reducing the fuel and 
reductant demands of current systems.
    Types of transmission technologies considered include:
     Improved automatic transmission controls --optimizes shift 
schedule to maximize fuel efficiency under wide ranging conditions, and 
minimizes losses associated with torque converter slip through lock-up 
or modulation.
     Six-, seven-, and eight-speed automatic transmissions--the 
gear ratio spacing and transmission ratio are optimized for a broader 
range of engine operating conditions specific to the mating engine.
    Types of vehicle technologies considered include:
     Low-rolling-resistance tires--have characteristics that 
reduce frictional losses associated with the energy dissipated in the 
deformation of the tires under load, therefore improving fuel 
efficiency and reducing CO2 emissions.
     Aerodynamic drag reduction--is achieved by changing 
vehicle shape or reducing frontal area, including skirts, air dams, 
underbody covers, and more aerodynamic side view mirrors.
     Mass reduction and material substitution--Mass reduction 
encompasses a variety of techniques ranging from improved design and 
better component integration to application of lighter and higher-
strength materials. Mass reduction is further compounded by reductions 
in engine power and ancillary systems (transmission, steering, brakes, 
suspension, etc.). The agencies recognize there is a range of diversity 
and complexity for mass reduction and material substitution 
technologies and there are many techniques that automotive suppliers 
and manufacturers are using to achieve the levels of this technology 
that the agencies have modeled in our analysis for this program.
    Types of electrification/accessory and hybrid technologies 
considered include:
     Electric power steering and Electro-Hydraulic power 
steering--are electrically-assisted steering systems that have 
advantages over traditional hydraulic power steering because it 
replaces a continuously operated hydraulic pump, thereby reducing 
parasitic losses from the accessory drive.
     Improved accessories--may include high efficiency 
alternators, electrically driven (i.e., on-demand) water pumps and 
cooling fans. This excludes other electrical accessories such as 
electric oil pumps and electrically driven air conditioner compressors.
     Air Conditioner Systems--These technologies include 
improved hoses, connectors and seals for leakage control. They also 
include improved compressors, expansion valves, heat exchangers and the 
control of these components for the purposes of improving tailpipe 
CO2 emissions as a result of A/C use.\250\
---------------------------------------------------------------------------

    \250\ See RIA Chapter 2.3 for more detailed technology 
descriptions.
---------------------------------------------------------------------------

(2) How did the agencies determine the costs and effectiveness of each 
of these technologies?
    Building on the technical analysis underlying the light-duty 2012-
2016 MY vehicle rule, the agencies took a fresh look at technology cost 
and effectiveness values for purposes of this final action. For costs, 
the agencies reconsidered both the direct or ``piece'' costs and 
indirect costs of individual components of technologies. For the direct 
costs, the agencies followed a bill of materials (BOM) approach 
employed by NHTSA and EPA in the light-duty rule.
    For two technologies, stoichiometric gasoline direct injection 
(SGDI) and turbocharging with engine downsizing, the agencies relied to 
the extent possible on the available tear-down data and scaling 
methodologies used in EPA's ongoing study with FEV, Incorporated. This 
study consists of complete system tear-down to evaluate technologies 
down to the nuts and bolts to arrive at very detailed estimates of the 
costs associated with manufacturing them.\251\
---------------------------------------------------------------------------

    \251\ U.S. Environmental Protection Agency, ``Draft Report--
Light-Duty Technology Cost Analysis Pilot Study,'' Contract No. EP-
C-07-069, Work Assignment 1-3, September 3, 2009.
---------------------------------------------------------------------------

    For the other technologies, considering all sources of information 
and using the BOM approach, the agencies worked together intensively to 
determine component costs for each of the technologies and build up the 
costs accordingly. Where estimates differ between sources, we have used 
engineering judgment to arrive at what we believe to be the best cost 
estimate available today, and explained the basis for that exercise of 
judgment.
    Once costs were determined, they were adjusted to ensure that they 
were all expressed in 2009 dollars using a ratio of gross domestic 
product (GDP) values for the associated calendar years,\252\ and 
indirect costs were accounted for using the new approach developed by 
EPA and used in the light-duty 2012-2016 MY vehicle rule. NHTSA and EPA 
also reconsidered how costs should be adjusted by modifying or scaling 
content assumptions to account for differences across the range of 
vehicle sizes and functional requirements, and adjusted the associated 
material cost impacts to account for the revised content, although some 
of these adjustments may be different for each agency due to the 
different vehicle subclasses used in their respective models.
---------------------------------------------------------------------------

    \252\ NHTSA examined the use of the CPI multiplier instead of 
GDP for adjusting these dollar values, but found the difference to 
be exceedingly small--only $0.14 over $100.
---------------------------------------------------------------------------

    Regarding estimates for technology effectiveness, NHTSA and EPA 
used the estimates from the light-duty rule as a baseline but adjusted 
them as appropriate, taking into account the unique requirement of the 
heavy-duty test cycles to test at curb weight plus half payload versus 
the light-duty requirement of curb plus 300 lb. The adjustments were 
made on an individual technology basis by assessing the specific impact 
of the added load on each technology when compared to the use of the 
technology on a light-duty vehicle. The agencies also considered other 
sources such as the 2010 NAS Report, recent CAFE compliance data, and 
confidential manufacturer estimates of technology effectiveness. NHTSA 
and EPA engineers reviewed effectiveness information from the multiple 
sources for each technology and ensured that such effectiveness 
estimates were based on technology hardware consistent with the BOM 
components used to estimate costs. Together, the agencies compared the 
multiple estimates and assessed their validity, taking care to ensure 
that common BOM definitions and other

[[Page 57222]]

vehicle attributes such as performance and drivability were taken into 
account.
    The agencies note that the effectiveness values estimated for the 
technologies may represent average values applied to the baseline fleet 
described earlier, and do not reflect the potentially-limitless 
spectrum of possible values that could result from adding the 
technology to different vehicles. For example, while the agencies have 
estimated an effectiveness of 0.5 percent for low friction lubricants, 
each vehicle could have a unique effectiveness estimate depending on 
the baseline vehicle's oil viscosity rating. Similarly, the reduction 
in rolling resistance (and thus the improvement in fuel efficiency and 
the reduction in CO2 emissions) due to the application of 
LRR tires depends not only on the unique characteristics of the tires 
originally on the vehicle, but on the unique characteristics of the 
tires being applied, characteristics which must be balanced between 
fuel efficiency, safety, and performance. Aerodynamic drag reduction is 
much the same--it can improve fuel efficiency and reduce CO2 
emissions, but it is also highly dependent on vehicle-specific 
functional objectives. For purposes of this NPRM, NHTSA and EPA believe 
that employing average values for technology effectiveness estimates is 
an appropriate way of recognizing the potential variation in the 
specific benefits that individual manufacturers (and individual 
vehicles) might obtain from adding a fuel-saving technology.
    The following section contains a detailed description of our 
assessment of vehicle technology cost and effectiveness estimates. The 
agencies note that the technology costs included in this NPRM take into 
account only those associated with the initial build of the vehicle.
(a) Engine Technologies
    NHTSA and EPA have reviewed the engine technology estimates used in 
the light-duty rule. In doing so NHTSA and EPA reconsidered all 
available sources and updated the estimates as appropriate. The section 
below describes both diesel and gasoline engine technologies considered 
for this program.
(i) Low Friction Lubricants
    One of the most basic methods of reducing fuel consumption in both 
gasoline and diesel engines is the use of lower viscosity engine 
lubricants. More advanced multi-viscosity engine oils are available 
today with improved performance in a wider temperature band and with 
better lubricating properties. This can be accomplished by changes to 
the oil base stock (e.g., switching engine lubricants from a Group I 
base oils to lower-friction, lower viscosity Group III synthetic) and 
through changes to lubricant additive packages (e.g., friction 
modifiers and viscosity improvers). The use of 5W-30 motor oil is now 
widespread and auto manufacturers are introducing the use of even lower 
viscosity oils, such as 5W-20 and 0W-20, to improve cold-flow 
properties and reduce cold start friction. However, in some cases, 
changes to the crankshaft, rod and main bearings and changes to the 
mechanical tolerances of engine components may be required. In all 
cases, durability testing would be required to ensure that durability 
is not compromised. The shift to lower viscosity and lower friction 
lubricants will also improve the effectiveness of valvetrain 
technologies such as cylinder deactivation, which rely on a minimum oil 
temperature (viscosity) for operation.
    Based on the light-duty 2012-2016 MY vehicle rule, and previously-
received confidential manufacturer data, NHTSA and EPA estimated the 
effectiveness of low friction lubricants to be between 0 to 1 percent.
    In the light-duty rule, the agencies estimated the cost of moving 
to low friction lubricants at $3 per vehicle (2007$). That estimate 
included a markup of 1.11 for a low complexity technology. For HD 
pickups and vans, we are using the same base estimate but have marked 
it up to 2009 dollars using the GDP price deflator and have used a 
markup of 1.24 for a low complexity technology to arrive at a value of 
$4 per vehicle. As in the light-duty rule, learning effects are not 
applied to costs for this technology and, as such, this estimate 
applies to all model years.253 254
---------------------------------------------------------------------------

    \253\ Note that throughout the cost estimates for this HD 
analysis, the agencies have used slightly higher markups than those 
used in the 2012-2016 MY light-duty vehicle rule. The new, slightly 
higher ICMs include return on capital of roughly 6%, a factor that 
was not included in the light-duty analysis. The markups are also 
higher than those used the in proposal for this action. That change 
has to do with our decision to base the ICMs solely on EPA internal 
work rather than averaging that work with earlier work done under 
contract to EPA by RTI, International. That change is discussed in 
Section VIII.C of this preamble and is detailed in Chapter 2 of the 
RIA (See RIA 2.2.1)
    \254\ Note that the costs developed for low friction lubes for 
this analysis reflect the costs associated with any engine changes 
that would be required as well as any durability testing that may be 
required.
---------------------------------------------------------------------------

(ii) Engine Friction Reduction
    In addition to low friction lubricants, manufacturers can also 
reduce friction and improve fuel consumption by improving the design of 
both diesel and gasoline engine components and subsystems. 
Approximately 10 percent of the energy consumed by a vehicle is lost to 
friction, and just over half is due to frictional losses within the 
engine.\255\ Examples include improvements in low-tension piston rings, 
piston skirt design, roller cam followers, improved crankshaft design 
and bearings, material coatings, material substitution, more optimal 
thermal management, and piston and cylinder surface treatments. 
Additionally, as computer-aided modeling software continues to improve, 
more opportunities for evolutionary friction reductions may become 
available.
---------------------------------------------------------------------------

    \255\ ``Impact of Friction Reduction Technologies on Fuel 
Economy,'' Fenske, G. Presented at the March 2009 Chicago Chapter 
Meeting of the `Society of Tribologists and Lubricated Engineers' 
Meeting, March 18th, 2009. Available at: http://www.chicagostle.org/program/2008-2009/Impact%20of%20Friction%20Reduction%20Technologies%20on%20Fuel%20Economy%20-%20with%20VGs%20removed.pdf (last accessed July 9, 2009).
---------------------------------------------------------------------------

    All reciprocating and rotating components in the engine are 
potential candidates for friction reduction, and minute improvements in 
several components can add up to a measurable fuel efficiency 
improvement. The light-duty 2012-2106 MY vehicle rule, the 2010 NAS 
Report, and NESCCAF and Energy and Environmental Analysis reports, as 
well as confidential manufacturer data, indicate a range of 
effectiveness for engine friction reduction to be between 1 to 3 
percent. NHTSA and EPA continue to believe that this range is accurate.
    Consistent with the light-duty rule, the agencies estimate the cost 
of this technology at $15 per cylinder compliance cost (2008$), 
including the low complexity ICM markup value of 1.24. Learning impacts 
are not applied to the costs of this technology and, as such, this 
estimate applies to all model years. This cost is multiplied by the 
number of engine cylinders.
(iii) Coupled Cam Phasing
    Valvetrains with coupled (or coordinated) cam phasing can modify 
the timing of both the inlet valves and the exhaust valves an equal 
amount by phasing the camshaft of an overhead valve engine. For 
overhead valve engines, which have only one camshaft to actuate both 
inlet and exhaust valves, couple cam phasing is the only variable valve 
timing implementation option available and requires only one cam 
phaser. Based on the light-duty rule, previously-received confidential 
manufacturer data, and the NESCCAF report, NHTSA and EPA estimated the 
effectiveness of couple cam phasing to be between 1 and 4 percent. 
NHTSA

[[Page 57223]]

and EPA reviewed this estimate for purposes of the NPRM, and continue 
to find it accurate.
    The agencies received comments questioning the exclusion of cam 
phasing from the technology packages. During the rulemaking process, 
manufacturers introduced many new or updated gasoline engines resulting 
in the majority of the 2010 gasoline heavy-duty engines including cam 
phasing, and so we now consider this technology to be in the baseline 
fleet. Because of this, the baseline analysis of technology for the 
2010 heavy-duty gasoline fleet already includes the benefits of cam 
phasing and therefore it is not appropriate for the agencies to include 
this as a technology that is available for most manufactures to add to 
their current gasoline engines.
(iv) Cylinder Deactivation
    In conventional spark-ignited engines throttling the airflow 
controls engine torque output. At partial loads, efficiency can be 
improved by using cylinder deactivation instead of throttling. Cylinder 
deactivation can improve engine efficiency by disabling or deactivating 
(usually) half of the cylinders when the load is less than half of the 
engine's total torque capability--the valves are kept closed, and no 
fuel is injected--as a result, the trapped air within the deactivated 
cylinders is simply compressed and expanded as an air spring, with 
reduced friction and heat losses. The active cylinders combust at 
almost double the load required if all of the cylinders were operating. 
Pumping losses are significantly reduced as long as the engine is 
operated in this ``part-cylinder'' mode.
    Cylinder deactivation control strategy relies on setting maximum 
manifold absolute pressures or predicted torque within a range in which 
it can deactivate the cylinders. Noise and vibration issues reduce the 
operating range to which cylinder deactivation is allowed, although 
manufacturers are exploring vehicle changes that enable increasing the 
amount of time that cylinder deactivation might be suitable. Some 
manufacturers may choose to adopt active engine mounts and/or active 
noise cancellations systems to address Noise Vibration and Harshness 
(NVH) concerns and to allow a greater operating range of activation. 
Cylinder deactivation is a technology keyed to more lightly loaded 
operation, and so may be a less likely technology choice for 
manufacturers designing for effectiveness in the loaded condition 
required for testing, and in the real world that involves frequent 
operation with heavy loads.
    Cylinder deactivation has seen a recent resurgence thanks to better 
valvetrain designs and engine controls. General Motors and Chrysler 
Group have incorporated cylinder deactivation across a substantial 
portion of their light-duty V8-powered lineups.
    Effectiveness improvements scale roughly with engine displacement-
to-vehicle weight ratio: The higher displacement-to-weight vehicles, 
operating at lower relative loads for normal driving, have the 
potential to operate in part-cylinder mode more frequently. For heavy-
duty vehicles tested and operated at loaded conditions, the power to 
weight ratio is considerably lower than the light-duty case greatly 
reducing the opportunity for ``part-cylinder'' mode and therefore was 
not considered in this rulemaking as an effective technology for heavy-
duty pickup truck and van applications.
(v) Stoichiometric Gasoline Direct Injection
    SGDI engines inject fuel at high pressure directly into the 
combustion chamber (rather than the intake port in port fuel 
injection). SGDI requires changes to the injector design, an additional 
high pressure fuel pump, new fuel rails to handle the higher fuel 
pressures and changes to the cylinder head and piston crown design. 
Direct injection of the fuel into the cylinder improves cooling of the 
air/fuel charge within the cylinder, which allows for higher 
compression ratios and increased thermodynamic efficiency without the 
onset of combustion knock. Recent injector design advances, improved 
electronic engine management systems and the introduction of multiple 
injection events per cylinder firing cycle promote better mixing of the 
air and fuel, enhance combustion rates, increase residual exhaust gas 
tolerance and improve cold start emissions. SGDI engines achieve higher 
power density and match well with other technologies, such as boosting 
and variable valvetrain designs.
    Several manufacturers have recently introduced vehicles with SGDI 
engines, including GM and Ford and have announced their plans to 
increase dramatically the number of SGDI engines in their portfolios.
    The light-duty 2012-2016 MY vehicle rule estimated the range of 1 
to 2 percent for SGDI. NHTSA and EPA reviewed this estimate for 
purposes of the NPRM, and continue to find it accurate.
    Consistent with the light-duty rule, NHTSA and EPA cost estimates 
for SGDI take into account the changes required to the engine hardware, 
engine electronic controls, ancillary and NVH mitigation systems. 
Through contacts with industry NVH suppliers, and manufacturer press 
releases, the agencies believe that the NVH treatments will be limited 
to the mitigation of fuel system noise, specifically from the injectors 
and the fuel lines. For this analysis, the agencies have estimated the 
costs at $481 (2009$) in the 2014 model year. Flat-portion of the curve 
learning is applied to this technology. This technology was considered 
for gasoline engines only, as diesel engines already employ direct 
injection.
(b) Diesel Engine Technologies
    Diesel engines have several characteristics that give them superior 
fuel efficiency compared to conventional gasoline, spark-ignited 
engines. Pumping losses are much lower due to lack of (or greatly 
reduced) throttling. The diesel combustion cycle operates at a higher 
compression ratio, with a very lean air/fuel mixture, and turbocharged 
light-duty diesels typically achieve much higher torque levels at lower 
engine speeds than equivalent-displacement naturally-aspirated gasoline 
engines. Additionally, diesel fuel has a higher energy content per 
gallon.\256\ However, diesel fuel also has a higher carbon to hydrogen 
ratio, which increases the amount of CO2 emitted per gallon 
of fuel used by approximately 15 percent over a gallon of gasoline.
---------------------------------------------------------------------------

    \256\ Burning one gallon of diesel fuel produces about 15 
percent more carbon dioxide than gasoline due to the higher density 
and carbon to hydrogen ratio.
---------------------------------------------------------------------------

    Based on confidential business information and the 2010 NAS Report, 
two major areas of diesel engine design will be improved during the 
2014-2018 time frame. These areas include aftertreatment improvements 
and a broad range of engine improvements.
(i) Aftertreatment Improvements
    The HD diesel pickup and van segment has largely adopted the SCR 
type of aftertreatment system to comply with criteria pollutant 
emission standards. As the experience base for SCR expands over the 
next few years, many improvements in this aftertreatment system such as 
construction of the catalyst, thermal management, and reductant 
optimization will result in a significant reduction in the amount of 
fuel used in the process. This technology was not considered in the 
light-duty rule. Based on confidential business information,

[[Page 57224]]

EPA and NHTSA estimate the reduction in CO2 as a result of 
these improvements at 3 to 5 percent.
    The agencies have estimated the cost of this technology at $25 for 
each percentage improvement in fuel consumption. This estimate is based 
on the agencies' belief that this technology is, in fact, a very cost 
effective approach to improving fuel consumption. As such, $25 per 
percent improvement is considered a reasonable cost. This cost would 
cover the engineering and test cell related costs necessary to develop 
and implement the improved control strategies that would allow for the 
improvements in fuel consumption. Importantly, the engineering work 
involved would be expected to result in cost savings to the 
aftertreatment and control hardware (lower platinum group metal 
loadings, lower reductant dosing rates, etc.). Those savings are 
considered to be included in the $25 per percent estimate described 
here. Given the 4 percent average expected improvement in fuel 
consumption results in an estimated cost of $119 (2009$) for a 2014 
model year truck or van. This estimate includes a low complexity ICM of 
1.24 and flat-portion of the curve learning from 2012 forward.
(ii) Engine Improvements
    Diesel engines in the HD pickup and van segment are expected to 
have several improvements in their base design in the 2014-2018 time 
frame. These improvements include items such as improved combustion 
management, optimal turbocharger design, and improved thermal 
management. This technology was not considered in the light-duty rule. 
Based on confidential business information, EPA and NHTSA estimate the 
reduction in CO2 as a result of these improvements at 4 to 6 
percent.
    The cost for this technology includes costs associated with low 
temperature exhaust gas recirculation, improved turbochargers and 
improvements to other systems and components. These costs are 
considered collectively in our costing analysis and termed ``diesel 
engine improvements.'' The agencies have estimated the cost of diesel 
engine improvements at $148 based on the cost estimates for several 
individual technologies. Specifically, the direct manufacturing costs 
we have estimated are: improved cylinder head, $9; turbo efficiency 
improvements, $16; EGR cooler improvements, $3; higher pressure fuel 
rail, $10; improved fuel injectors, $13; improved pistons, $2; and 
reduced valve train friction, $95. All values are in 2009 dollars and 
are applicable in the 2014 MY. Applying a low complexity ICM of 1.24 
results in a cost of $184 (2009$) applicable in the 2014 MY. We 
consider flat-portion of the curve learning to be appropriate for these 
technologies.
(c) Transmission Technologies
    NHTSA and EPA have also reviewed the transmission technology 
estimates used in the light-duty rule. In doing so, NHTSA and EPA 
considered or reconsidered all available sources and updated the 
estimates as appropriate. The section below describes each of the 
transmission technologies considered for the final standards.
(i) Improved Automatic Transmission Control (Aggressive Shift Logic and 
Early Torque Converter Lockup)
    Calibrating the transmission shift schedule to upshift earlier and 
quicker, and to lock-up or partially lock-up the torque converter under 
a broader range of operating conditions can reduce fuel consumption and 
CO2 emissions. However, this operation can result in a 
perceptible degradation in NVH. The degree to which NVH can be degraded 
before it becomes noticeable to the driver is strongly influenced by 
characteristics of the vehicle, and although it is somewhat subjective, 
it always places a limit on how much fuel consumption can be improved 
by transmission control changes. Given that the Aggressive Shift Logic 
and Early Torque Converter Lockup are best optimized simultaneously due 
to the fact that adding both of them primarily requires only minor 
modifications to the transmission or calibration software, these two 
technologies are combined in the modeling. We consider these 
technologies to be present in the baseline, since 6-speed automatic 
transmissions are installed in the majority of Class 2b and 3 trucks in 
the 2010 model year time frame.
(ii) Automatic 6- and 8-Speed Transmissions
    Manufacturers can also choose to replace 4- 5- and 6-speed 
automatic transmissions with 8-speed automatic transmissions. 
Additional ratios allow for further optimization of engine operation 
over a wider range of conditions, but this is subject to diminishing 
returns as the number of speeds increases. As additional planetary gear 
sets are added (which may be necessary in some cases to achieve the 
higher number of ratios), additional weight and friction are 
introduced. Also, the additional shifting of such a transmission can be 
perceived as bothersome or busy to some consumers, so manufacturers 
need to develop strategies for smooth shifts. Some manufacturers are 
replacing 4- and 5-speed automatics with 6-speed automatics already, 
and 7- and 8-speed automatics have entered production in light-duty 
vehicles, albeit in lower-volume applications in luxury and performance 
oriented cars.
    As discussed in the light-duty rule, confidential manufacturer data 
projected that 6-speed transmissions could incrementally reduce fuel 
consumption by 0 to 5 percent from a 4-speed automatic transmission, 
while an 8-speed transmission could incrementally reduce fuel 
consumption by up to 6 percent from a 4-speed automatic transmission. 
GM has publicly claimed a fuel economy improvement of up to 4 percent 
for its new 6-speed automatic transmissions.\257\
---------------------------------------------------------------------------

    \257\ General Motors, news release, ``From Hybrids to Six-
Speeds, Direct Injection And More, GM's 2008 Global Powertrain 
Lineup Provides More Miles with Less Fuel'' (released Mar. 6, 2007). 
Available at http:// www.gm.com/ experience/ fuel-- economy/ news/ 
2007/ adv-- engines/ 2008- powertrain- lineup- 082707.jsp (last 
accessed Sept. 18, 2008).
---------------------------------------------------------------------------

    NHTSA and EPA reviewed and revised these effectiveness estimates 
based on actual usage statistics and testing methods for these vehicles 
along with confidential business information. When combined with 
improved automatic transmission control, the agencies estimate the 
effectiveness for a conversion from a 4- to a 6-speed transmission to 
be 5.3 percent and a conversion from a 6- to 8-speed transmission to be 
1.7 percent. While 8-speed transmissions were not considered in the 
light-duty 2012-2016 MY vehicle rule, they are considered as a 
technology of choice for this analysis in that manufacturers are 
expected to upgrade the 6-speed automatic transmissions being 
implemented today with 8-speed automatic transmissions in the 2014-2018 
time frame. We are estimating the cost of an 8-speed automatic 
transmission at $281 (2009$) relative to a 6-speed automatic 
transmission in the 2014 model year. This estimate is based from the 
2010 NAS Report and we have applied a low complexity ICM of 1.24 and 
flat-portion of the curve learning. This technology applies to both 
gasoline and diesel pickup trucks and vans.
(d) Electrification/Accessory Technologies
(i) Electrical Power Steering or Electrohydraulic Power Steering
    Electric power steering (EPS) or Electrohydraulic power steering 
(EHPS) provides a potential reduction in CO2 emissions and 
fuel consumption over

[[Page 57225]]

hydraulic power steering because of reduced overall accessory loads. 
This eliminates the parasitic losses associated with belt-driven power 
steering pumps which consistently draw load from the engine to pump 
hydraulic fluid through the steering actuation systems even when the 
wheels are not being turned. EPS is an enabler for all vehicle 
hybridization technologies since it provides power steering when the 
engine is off. EPS may be implemented on most vehicles with a standard 
12V system. Some heavier vehicles may require a higher voltage system 
which may add cost and complexity.
    The light-duty rule estimated a one to two percent effectiveness 
based on the 2002 NAS report for light-duty vehicle technologies, a 
Sierra Research report, and confidential manufacturer data. NHTSA and 
EPA reviewed these effectiveness estimates and found them to be 
accurate, thus they have been retained for purposes of this NPRM.
    NHTSA and EPA adjusted the EPS cost for the current rulemaking 
based on a review of the specification of the system. Adjustments were 
made to include potentially higher voltage or heavier duty system 
operation for HD pickups and vans. Accordingly, higher costs were 
estimated for systems with higher capability. After accounting for the 
differences in system capability and applying the ICM markup of low 
complexity technology of 1.24, the estimated costs are $115 for a MY 
2014 truck or van (2009$). As EPS systems are in widespread usage 
today, flat-portion of the curve learning is deemed applicable. EHPS 
systems are considered to be of equal cost and both are considered 
applicable to gasoline and diesel engines.
(ii) Improved Accessories
    The accessories on an engine, including the alternator, coolant and 
oil pumps are traditionally mechanically-driven. A reduction in 
CO2 emissions and fuel consumption can be realized by 
driving the pumping accessories electrically, and only when needed 
(``on-demand''). Alternator improvements include internal changes 
resulting in lower mechanical and electrical losses combined with 
control logic that charges the battery at more efficient voltage levels 
and during conditions of available kinetic energy from the vehicle 
which would normally be wasted energy such as braking during vehicle 
decelerations.
    Electric water pumps and electric fans can provide better control 
of engine cooling. For example, coolant flow from an electric water 
pump can be reduced and the radiator fan can be shut off during engine 
warm-up or cold ambient temperature conditions which will reduce warm-
up time, reduce warm-up fuel enrichment, and reduce parasitic losses.
    Indirect benefit may be obtained by reducing the flow from the 
water pump electrically during the engine warm-up period, allowing the 
engine to heat more rapidly and thereby reducing the fuel enrichment 
needed during cold starting of the engine. Further benefit may be 
obtained when electrification is combined with an improved, higher 
efficiency engine alternator. Intelligent cooling can more easily be 
applied to vehicles that do not typically carry heavy payloads, so 
larger vehicles with towing capacity present a challenge, as these 
vehicles have high cooling fan loads.\258\
---------------------------------------------------------------------------

    \258\ In the CAFE model, improved accessories refer solely to 
improved engine cooling. However, EPA has included a high efficiency 
alternator in this category, as well as improvements to the cooling 
system.
---------------------------------------------------------------------------

    The agencies considered whether to include electric oil pump 
technology for the rulemaking. Because it is necessary to operate the 
oil pump any time the engine is running, electric oil pump technology 
has insignificant effect on efficiency. Therefore, the agencies decided 
to not include electric oil pump technology.
    NHTSA and EPA jointly reviewed the estimates of 1 to 2 percent 
effectiveness estimates used in the light-duty rule and found them to 
be accurate for Improved Electrical Accessories. Consistent with the 
light-duty rule, the agencies have estimated the cost of this 
technology at $93 (2009$) including a low complexity ICM of 1.24. This 
cost is applicable in the 2014 model year. Improved accessory systems 
are in production currently and thus flat-portion of the curve learning 
is applied. This technology was considered for diesel pickup trucks and 
vans only.
(e) Vehicle Technologies
(i) Mass Reduction
    Reducing a vehicle's mass, or down-weighting the vehicle, decreases 
fuel consumption by reducing the energy demand needed to overcome 
forces resisting motion, and rolling resistance. Manufacturers employ a 
systematic approach to mass reduction, where the net mass reduction is 
the addition of a direct component or system mass reduction plus the 
additional mass reduction taken from indirect ancillary systems and 
components, as a result of full vehicle optimization, effectively 
compounding or obtaining a secondary mass reduction from a primary mass 
reduction. For example, use of a smaller, lighter engine with lower 
torque-output subsequently allows the use of a smaller, lighter-weight 
transmission and drive line components. Likewise, the compounded weight 
reductions of the body, engine and drivetrain reduce stresses on the 
suspension components, steering components, wheels, tires and brakes, 
allowing further reductions in the mass of these subsystems. The 
reductions in unsprung masses such as brakes, control arms, wheels and 
tires further reduce stresses in the suspension mounting points. This 
produces a compounding effect of mass reductions.
    Estimates of the synergistic effects of mass reduction and the 
compounding effect that occurs along with it can vary significantly 
from one report to another. For example, in discussing its estimate, an 
Auto-Steel Partnership report states that ``These secondary mass 
changes can be considerable--estimated at an additional 0.7 to 1.8 
times the initial mass change.'' \259\ This means for each one pound 
reduction in a primary component, up to 1.8 pounds can be reduced from 
other structures in the vehicle (i.e., a 180 percent factor). The 
report also discusses that a primary variable in the realized secondary 
weight reduction is whether or not the powertrain components can be 
included in the mass reduction effort, with the lower end estimates 
being applicable when powertrain elements are unavailable for mass 
reduction. However, another report by the Aluminum Association, which 
primarily focuses on the use of aluminum as an alternative material for 
steel, estimated a factor of 64 percent for secondary mass reduction 
even though some powertrain elements were considered in the 
analysis.\260\ That report also notes that typical values for this 
factor vary from 50 to 100 percent. Although there is a wide variation 
in stated estimates, synergistic mass reductions do exist, and the 
effects result in tangible mass reductions. Mass reductions in a single 
vehicle component, for example a door side

[[Page 57226]]

impact/intrusion system, may actually result in a significantly higher 
weight savings in the total vehicle, depending on how well the 
manufacturer integrates the modification into the overall vehicle 
design. Accordingly, care must be taken when reviewing reports on 
weight reduction methods and practices to ascertain if compounding 
effects have been considered or not.
---------------------------------------------------------------------------

    \259\ ``Preliminary Vehicle Mass Estimation Using Empirical 
Subsystem Influence Coefficients,'' Malen, D.E., Reddy, K. Auto-
Steel Partnership Report, May 2007, Docket EPA-HQ-OAR-2009-0472-
0169. Accessed on the Internet on May 30, 2009 at: http://www.a-sp.org/database/custom/Mass%20Compounding%20-%20Final%20Report.pdf.
    \260\ ``Benefit Analysis: Use of Aluminum Structures in 
Conjunction with Alternative Powertrain Technologies in 
Automobiles,'' Bull, M. Chavali, R., Mascarin, A., Aluminum 
Association Research Report, May 2008, Docket EPA-HQ-OAR-2009-0472-
0168. Accessed on the Internet on April 30, 2009 at: http://www.autoaluminum.org/downloads/IBIS-Powertrain-Study.pdf.
---------------------------------------------------------------------------

    Mass reduction is broadly applicable across all vehicle subsystems 
including the engine, exhaust system, transmission, chassis, 
suspension, brakes, body, closure panels, glazing, seats and other 
interior components, engine cooling systems and HVAC systems. It is 
estimated that up to 1.25 kilograms of secondary weight savings can be 
achieved for every kilogram of weight saved on a light-duty vehicle 
when all subsystems are redesigned to take into account the initial 
primary weight savings.261 262
---------------------------------------------------------------------------

    \261\ ``Future Generation Passenger Compartment-Validation (ASP 
241)'' Villano, P.J., Shaw, J.R., Polewarczyk, J., Morgans, S., 
Carpenter, J.A., Yocum, A.D., in ``Lightweighting Materials--FY 2008 
Progress Report,'' U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Vehicle Technologies Program, May 
2009, Docket EPA-HQ-OAR-2009-0472-0190.
    \262\ ``Preliminary Vehicle Mass Estimation Using Empirical 
Subsystem Influence Coefficients,'' Malen, D.E., Reddy, K. Auto-
Steel Partnership Report, May 2007, Docket EPA-HQ-OAR-2009-0472-
0169. Accessed on the Internet on May 30, 2009 at: http://www.a-sp.org/database/custom/Mass%20Compounding%20-%20Final%20Report.pdf.
---------------------------------------------------------------------------

    Mass reduction can be accomplished by proven methods such as:
     Smart Design: Computer aided engineering (CAE) tools can 
be used to better optimize load paths within structures by reducing 
stresses and bending moments applied to structures. This allows better 
optimization of the sectional thicknesses of structural components to 
reduce mass while maintaining or improving the function of the 
component. Smart designs also integrate separate parts in a manner that 
reduces mass by combining functions or the reduced use of separate 
fasteners. In addition, some ``body on frame'' vehicles are redesigned 
with a lighter ``unibody'' construction.
     Material Substitution: Substitution of lower density and/
or higher strength materials into a design in a manner that preserves 
or improves the function of the component. This includes substitution 
of high-strength steels, aluminum, magnesium or composite materials for 
components currently fabricated from mild steel.
     Reduced Powertrain Requirements: Reducing vehicle weight 
sufficiently allows for the use of a smaller, lighter and more 
efficient engine while maintaining or increasing performance. 
Approximately half of the reduction is due to these reduced powertrain 
output requirements from reduced engine power output and/or 
displacement, changes to transmission and final drive gear ratios. The 
subsequent reduced rotating mass (e.g., transmission, driveshafts/
halfshafts, wheels and tires) via weight and/or size reduction of 
components are made possible by reduced torque output requirements.
     Automotive companies have largely used weight savings in 
some vehicle subsystems to offset or mitigate weight gains in other 
subsystems from increased feature content (sound insulation, 
entertainment systems, improved climate control, panoramic roof, etc.).
     Lightweight designs have also been used to improve vehicle 
performance parameters by increased acceleration performance or 
superior vehicle handling and braking.
    Many manufacturers have already announced final future products 
plans reducing the weight of a vehicle body through the use of high 
strength steel body-in-white, composite body panels, magnesium alloy 
front and rear energy absorbing structures reducing vehicle weight 
sufficiently to allow a smaller, lighter and more efficient engine. 
Nissan will be reducing average vehicle curb weight by 15 percent by 
2015.\263\ Ford has identified weight reductions of 250 to 750 lb per 
vehicle as part of its implementation of known technology within its 
sustainability strategy between 2011 and 2020.\264\ Mazda plans to 
reduce vehicle weight by 220 pounds per vehicle or more as models are 
redesigned.265 266 Ducker International estimates that the 
average curb weight of light-duty vehicle fleet will decrease 
approximately 2.8 percent from 2009 to 2015 and approximately 6.5 
percent from 2009 to 2020 via changes in automotive materials and 
increased change-over from previously used body-on-frame automobile and 
light-truck designs to newer unibody designs.\263\ While the 
opportunity for mass reductions available to the light-duty fleet may 
not in all cases be applied directly to the heavy-duty fleet due to the 
different designs for the expected duty cycles of a ``work'' vehicle, 
mass reductions are still available particularly to areas unrelated to 
the components and systems necessary for the work vehicle aspects.
---------------------------------------------------------------------------

    \263\ ``Lighten Up!,'' Brooke, L., Evans, H. Automotive 
Engineering International, Vol. 117, No. 3, March 2009.
    \264\ ``2008/9 Blueprint for Sustainability,'' Ford Motor 
Company. Available at: http://www.ford.com/go/sustainability (last 
accessed February 8, 2010).
    \265\ ``Mazda to cut vehicle fuel consumption 30 percent by 
2015,'' Mazda press release, June 23, 2009. Available at: http://www.mazda.com/publicity/release/2008/200806/080623.html (last 
accessed February 8, 2010).
    \266\ ``Mazda: Don't believe hot air being emitted by hybrid 
hype,'' Greimel, H. Automotive News, March 30, 2009.
---------------------------------------------------------------------------

    Due to the payload and towing requirements of these heavy-duty 
vehicles, engine downsizing was not considered in the estimates for 
CO2 reduction in the area of mass reduction and material 
substitution. NHTSA and EPA estimate that a 3 percent mass reduction 
with no engine downsizing results in a 1 percent reduction in fuel 
consumption. In addition, a 5 and 10 percent mass reduction with no 
engine downsizing result in an estimated CO2 reduction of 
1.6 and 3.2 percent respectively. These effectiveness values are 50 
percent of the light-duty rule values due to the elimination of engine 
downsizing for this class of vehicle.
    In the NPRM, EPA and NHTSA relied on three studies to estimate the 
cost of vehicle mass reduction. The agencies used a value of $1.32 per 
pound of mass reduction that was derived from a 2002 National Academy 
of Sciences study, a 2008 Sierra Research report, and a 2008 MIT study. 
The cost was estimated to be constant, independent of the level of mass 
reduction.
    The agencies along with the California Air Resources Board (CARB) 
have recently completed work on an Interim Joint Technical Assessment 
Report (TAR) that considers light-duty GHG and fuel economy standards 
for model years 2017 through 2025 and have continued this work to 
support the light-duty vehicle NPRM, which is expected to be issued 
this fall. Based on new information from various industry and 
literature sources, the TAR modified the mass reduction/cost 
relationship used in the light-duty 2012-2016 MY vehicle rule to begin 
at the origin (zero cost at zero percent mass reduction) and to have 
increasing cost with increasing mass reduction.\267\ The resulting 
analysis showed costs for 5 percent mass reduction on light-duty 
vehicles to be near zero or cost parity.
---------------------------------------------------------------------------

    \267\ ``Interim Joint Technical Assessment Report: Light-Duty 
Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel 
Economy Standards for Model Years 2017-2025;'' September 2010; 
available at http://epa.gov/otaq/climate/regulations/ldv-ghg-tar.pdf 
and in the docket for this rule.
---------------------------------------------------------------------------

    In the proposal for heavy-duty vehicles, we estimated mass 
reduction costs based on the 2012-2016 light-duty analysis without 
accounting for the new work completed in the Interim Joint Technical 
Assessment and additional

[[Page 57227]]

work the agencies have considered for the upcoming light-duty vehicle 
NPRM. Since the heavy-duty vehicle proposal, the agencies have been 
able to consider updated cost estimates in the context of both light-
duty and heavy-duty vehicle bodies of work. While the agencies intend 
to discuss the additional work for the light-duty NPRM in much more 
detail in the documents for that rulemaking, we think it appropriate to 
explain here that after having considered a number of additional and 
highly-varying sources, the agencies believe that the cost estimates 
used in the TAR may have been lower than would be reasonable for HD 
pickups and vans, given their different and work-related uses and thus 
different construction as compared to the light-duty vehicles evaluated 
in the TAR. We do not believe that all of the weight reduction 
opportunities for light-duty vehicles can be applied to heavy-duty 
trucks. However, we do believe reductions in the following components 
and systems can be found that do not affect the payload and towing 
requirements of these heavy-duty vehicles: Body, closure panels, 
glazing, seats and other interior components, engine cooling systems 
and HVAC systems.
    The agencies have reviewed and considered many different mass 
reduction studies during the technical assessment for the heavy-duty 
vehicle GHG and fuel efficiency rulemaking. The agencies found that 
many of the studies on this topic vary considerably in their rigor, 
transparency, and applicability to the regulatory assessment. Having 
considered a variety of options, the agencies for this heavy-duty 
analysis have been unable to come up with a way to quantitatively 
evaluate the available studies. Therefore, the agencies have chosen a 
value within the range of the available studies that the agencies 
believe is reasonable. The studies and manufacturers' confidential 
business information relied upon in determining the final mass 
reduction costs are summarized in Figure 2.1, Section 2.3.6 of the RIA. 
Each study relied upon by the agencies in this determination has also 
been placed in the agencies' respective dockets. See NHTSA-2010-0079; 
EPA-HQ-0AR-2010-0162.
    The agencies note that the NAS 2010 study provided estimates of 
mass reduction costs, but the agencies did not consider using the NAS 
2010 study as the single source of mass reduction cost estimates 
because the NAS 2010 estimates were not based on literature reports 
that focused on trucks or were necessarily appropriate for MD/HD 
vehicles, and also because a variety of newer and more rigorous studies 
were available to the agencies than those relied upon by the NAS in 
developing its estimates. We note, however, that for a 5 percent 
reduction in mass, the NAS 2010 report estimates a per pound cost of 
mass reduction of $1.65.
    Thus, we are estimating the direct manufacturing costs for a 5 
percent mass reduction of a 6,000 lb vehicle at a range of $75-$90 per 
vehicle. With additional margin for uncertainty, we arrive at a direct 
manufacturing cost of $85-$100, which is roughly in the upper middle of 
the range of values that resulted from the additional and highly-
varying studies mentioned above that were considered in the agencies' 
review. We have broken this down for application to HD pickup trucks 
and vans as follows: Class 2b gasoline $85, Class 2b diesel $95, Class 
3 gasoline $90, and Class 3 diesel trucks $100. Applying the low 
complexity ICM of 1.24 results in estimated total costs for a 5 percent 
mass reduction applicable in the 2016 model year as follows: Class 2b 
gasoline $108, Class 2b diesel $121, Class 3 gasoline $115, and Class 3 
diesel trucks $127. All mass reduction costs stated here are in 2009 
dollars.
(ii) Low Rolling Resistance Tires
    Tire rolling resistance is the frictional loss associated mainly 
with the energy dissipated in the deformation of the tires under load 
and thus influences fuel efficiency and CO2 emissions. Other 
tire design characteristics (e.g., materials, construction, and tread 
design) influence durability, traction (both wet and dry grip), vehicle 
handling, and ride comfort in addition to rolling resistance. A typical 
LRR tire's attributes would include: increased tire inflation pressure, 
material changes, and tire construction with less hysteresis, geometry 
changes (e.g., reduced aspect ratios), and reduction in sidewall and 
tread deflection. These changes would generally be accompanied with 
additional changes to suspension tuning and/or suspension design.
    EPA and NHTSA estimated a 1 to 2 percent increase in effectiveness 
with a 10 percent reduction in rolling resistance, which was based on 
the 2010 NAS Report findings and consistent with the light-duty rule.
    Based on the light-duty rule and the 2010 NAS Report, the agencies 
have estimated the cost for LRR tires to be $7 per Class 2b truck or 
van, and $10 per Class 3 truck or van (both values in 2009$ and 
inclusive of a 1.24 low complexity markup).\268\ The higher cost for 
the Class 3 trucks and vans is due to the predominant use of dual rear 
tires and, thus, 6 tires per truck. Due to the commodity-based nature 
of this technology, cost reductions due to learning are not applied. 
This technology is considered applicable to both gasoline and diesel.
---------------------------------------------------------------------------

    \268\ ``Tires and Passenger Vehicle Fuel Economy,'' 
Transportation Research Board Special Report 286, National Research 
Council of the National Academies, 2006, Docket EPA-HQ-OAR-2009-
0472-0146.
---------------------------------------------------------------------------

(iii) Aerodynamic Drag Reduction
    Many factors affect a vehicle's aerodynamic drag and the resulting 
power required to move it through the air. While these factors change 
with air density and the square and cube of vehicle speed, 
respectively, the overall drag effect is determined by the product of 
its frontal area and drag coefficient, Cd. Reductions in these 
quantities can therefore reduce fuel consumption and CO2 
emissions. Although frontal areas tend to be relatively similar within 
a vehicle class (mostly due to market-competitive size requirements), 
significant variations in drag coefficient can be observed. Significant 
changes to a vehicle's aerodynamic performance may need to be 
implemented during a redesign (e.g., changes in vehicle shape). 
However, shorter-term aerodynamic reductions, with a somewhat lower 
effectiveness, may be achieved through the use of revised exterior 
components (typically at a model refresh in mid-cycle) and add-on 
devices that currently are being applied. The latter list would include 
revised front and rear fascias, modified front air dams and rear 
valances, addition of rear deck lips and underbody panels, and lower 
aerodynamic drag exterior mirrors.
    The light-duty 2012-2016 MY vehicle rule estimated that a fleet 
average of 10 to 20 percent total aerodynamic drag reduction is 
attainable which equates to incremental reductions in fuel consumption 
and CO2 emissions of 2 to 3 percent for both cars and 
trucks. These numbers are generally supported by confidential 
manufacturer data and public technical literature. For the heavy-duty 
truck category, a 5 to 10 percent total aerodynamic drag reduction was 
considered due to the different structure and use of these vehicles 
equating to incremental reductions in fuel consumption and 
CO2 emissions of 1 to 2 percent.
    Consistent with the light-duty rule, the agencies have estimated 
the cost for this technology at $58 (2009$) including a low complexity 
ICM of 1.24. This cost is applicable in the 2014 model year to

[[Page 57228]]

both gasoline and diesel pickup trucks and vans.
(3) What are the projected technology packages' effectiveness and cost?
    The assessment of the final technology effectiveness was developed 
through the use of the EPA Lumped Parameter model developed for the 
light-duty rule. Many of the technologies were common with the light-
duty assessment but the effectiveness of individual technologies was 
appropriately adjusted to match the expected effectiveness when 
implemented in a heavy-duty application. The model then uses the 
individual technology effectiveness levels but then takes into account 
technology synergies. The model is also designed to prevent double 
counting from technologies that may directly or indirectly impact the 
same physical attribute (e.g., pumping loss reductions).
    To achieve the levels of the final standards for gasoline and 
diesel powered heavy-duty vehicles, the technology packages were 
determined to generally require the technologies previously discussed 
respective to unique gasoline and diesel technologies. Although some of 
the technologies may already be implemented in a portion of heavy-duty 
vehicles, none of the technologies discussed are considered ubiquitous 
in the heavy-duty fleet. Also, as would be expected, the available test 
data shows that some vehicle models will not need the full complement 
of available technologies to achieve the final standards. Furthermore, 
many technologies can be further improved (e.g., aerodynamic 
improvements) from today's best levels, and so allow for compliance 
without needing to apply a technology that a manufacturer might deem 
less desirable.
    Technology costs for HD pickup trucks and vans are shown in Table 
III-11.

  Table III-11--Technology Costs for HD Pickup Trucks & Vans Inclusive of Indirect Cost Markups for the 2014MY
                                                     [2009$]
----------------------------------------------------------------------------------------------------------------
                                                                Class 2b     Class 2b     Class 3      Class 3
                         Technology                             gasoline      diesel      gasoline      diesel
----------------------------------------------------------------------------------------------------------------
Low friction lubes..........................................           $4           $4           $4           $4
Engine friction reduction...................................          116          N/A          116          N/A
Stoichiometric gasoline direct injection....................          481          N/A          481          N/A
Engine improvements.........................................          N/A          184          N/A          184
8s automatic transmission (increment to 6s automatic                  281          281          281          281
 transmission)..............................................
Improved accessories........................................          N/A           93          N/A           93
Low rolling resistance tires................................            7            7           10           10
Aerodynamic improvements....................................           58           58           58           58
Electric (or electro/hydraulic) power steering..............          115          115          115          115
Aftertreatment improvements.................................          N/A          119          N/A          119
Mass reduction (5%).........................................          108          121          115          127
Air conditioning............................................           21           21           21           21
    Total...................................................        1,190        1,003        1,209        1,013
                                                             ---------------------------------------------------
At 15% phase-in in 2014.....................................          179          150          180          152
----------------------------------------------------------------------------------------------------------------

(4) Reasonableness of the Final Standards
    The final standards are based on the application of the control 
technologies described in this section. These technologies are 
available within the lead time provided, as discussed in RIA Chapter 
2.3. These controls are estimated to add costs of approximately $1,048 
for MY 2018 heavy-duty pickups and vans. Reductions associated with 
these costs and technologies are considerable, estimated at a 12 
percent reduction of CO2eq emissions from the MY 2010 
baseline for gasoline engine-equipped vehicles and 17 percent for 
diesel engine equipped vehicles, estimated to result in reductions of 
18 MMT of CO2eq emissions over the lifetimes of 2014 through 
2018 MY vehicles.\269\ The reductions are cost effective, estimated at 
$90 per ton of CO2eq removed in 2030.\270\ This cost is 
consistent with the light-duty rule which was estimated at $100 per ton 
of CO2eq removed in 2020 excluding fuel savings. Moreover, 
taking into account the fuel savings associated with the program, the 
cost becomes -$230 per ton of CO2eq (i.e. a savings of $230 
per ton) in 2030. The cost of controls is fully recovered due to the 
associated fuel savings, with a payback period in the second year of 
ownership, as shown in Table VIII-9 below in Section VIII. Given the 
large, cost effective emission reductions based on use of feasible 
technologies which are available in the lead time provided, plus the 
lack of adverse impacts on vehicle safety or utility, EPA and NHTSA 
regard these final standards as appropriate and consistent with our 
respective statutory authorities under CAA section 202(a) and NHTSA's 
EISA authority under 49 U.S.C. 32902(k)(2). Based on the discussion 
above, NHTSA believes these standards are the maximum feasible under 
EISA.
---------------------------------------------------------------------------

    \269\ See Table VI-4 of this preamble.
    \270\ See Table 0-3 of this preamble.
---------------------------------------------------------------------------

(5) Alternative HD Pickup Truck and Van Standards Considered
    The agencies rejected consideration of any less stringent standards 
given that the standards adopted are feasible at reasonable cost and 
cost-effectiveness within the lead time of the program. Furthermore, as 
explained above, because the standards are premised on 100 percent 
application of available technologies during this period, the agencies 
rejected adoption of more stringent standards. The agencies have also 
explained above why the phase-in period for the standards is reasonable 
and that attempting more aggressive phase-ins would start to force 
changes outside normal redesign cycles at likely exorbitant cost.

C. Class 2b-8 Vocational Vehicles

    Vocational vehicles cover a wide variety of applications which 
influence both the body style and usage patterns. They also are built 
using a complex process, which includes additional entities such as 
body builders. These factors create special sensitivity to

[[Page 57229]]

concerns of needed lead time, as well as developing standards that do 
not interfere with vocational vehicles' utility. The agencies are 
adopting a standard for vocational vehicles for the first phase of the 
program that relies on less extensive addition of technology than do 
the other regulatory categories as well as making the chassis 
manufacturer the manufacturer subject to the standard. We intend that 
future rulemakings will consider increased stringency and possibly more 
application-specific standards. The agencies are also finalizing 
standards for the diesel and gasoline engines installed in vocational 
vehicles, similar to those discussed above for HD engines installed in 
Class 7 and 8 tractors.
(1) What technologies did the agencies consider to reduce the 
CO2 emissions and fuel consumption of vocational vehicles?
    Similar to the approach taken with tractors, the agencies evaluated 
aerodynamic, tire, idle reduction, weight reduction, hybrid powertrain, 
and engine technologies and their impact on reducing fuel consumption 
and GHG emissions. The engines used in vocational vehicles include both 
gasoline and diesel engines, thus, each type is discussed separately 
below. As explained in Section II.D.1.b, the final regulatory structure 
for heavy-duty engines separates the compression ignition (or 
``diesel'') engines into three regulatory subcategories--light heavy, 
medium heavy, and heavy heavy diesel engines--while spark ignition (or 
``gasoline'') engines are a single regulatory subcategory (an approach 
for which there was consensus in the public comments). Therefore, the 
subsequent discussion will assess each type of engine separately.
(a) Vehicle Technologies
    Vocational vehicles typically travel fewer miles than combination 
tractors. They also tend to be used in more urban locations (with 
consequent stop and start drive cycles). Therefore the average speed of 
vocational vehicles is significantly lower than combination tractors. 
This has a significant effect on the types of technologies that are 
appropriate to consider for reducing CO2 emissions and fuel 
consumption.
    The agencies considered the type of technologies for vocational 
vehicles based on the energy losses of a typical vocational vehicle. 
The technologies are similar to the ones considered for combination 
tractors. Argonne National Lab conducted an energy audit using 
simulation tools to evaluate the energy losses of vocational vehicles, 
such as a Class 6 pickup and delivery truck. Argonne found that 74 
percent of the energy losses are attributed to the engine, 13 percent 
to tires, 9 percent to aerodynamics, two percent to transmission 
losses, and the remaining four percent of losses to axles and 
accessories for a medium-duty truck traveling at 30 mph.\271\
---------------------------------------------------------------------------

    \271\ Argonne National Lab. Evaluation of Fuel Consumption 
Potential of Medium and Heavy-duty Vehicles through Modeling and 
Simulation. October 2009. Page 89.
---------------------------------------------------------------------------

    Low Rolling Resistance Tires: Tires are the second largest 
contributor to energy losses of vocational vehicles, as found in the 
energy audit conducted by Argonne National Lab (as just mentioned). The 
range of rolling resistance of tires used on vocational vehicles today 
is large. This is in part due to the fact that the competitive pressure 
to improve rolling resistance of vocational vehicle tires has been less 
than that found in the line haul tire market. In addition, the drive 
cycles typical for these applications often lead truck buyers to value 
tire traction and durability more heavily than rolling resistance. 
Therefore, the agencies concluded that a regulatory program that seeks 
to optimize tire rolling resistance in addition to traction and 
durability can bring about fuel consumption and CO2 emission 
reductions from this segment. The 2010 NAS report states that rolling 
resistance impact on fuel consumption reduces with mass of the vehicle 
and with drive cycles with more frequent starts and stops. The report 
found that the fuel consumption reduction opportunity for reduced 
rolling resistance ranged between one and three percent in the 2010 
through 2020 time frame.\272\ The agencies estimate that average 
rolling resistance from tires in 2010 model year can be reduced by 10 
percent for 50 percent of the vehicles by 2014 model year based on the 
tire development achievements over the last several years in the line 
haul truck market.
---------------------------------------------------------------------------

    \272\ See 2010 NAS Report, Note 197, page 146.
---------------------------------------------------------------------------

    Aerodynamics: The Argonne National lab work shows that aerodynamics 
has less of an impact on vocational vehicle energy losses than do 
engines or tires. In addition, the aerodynamic performance of a 
complete vehicle is significantly influenced by the body of the 
vehicle. The agencies are not regulating body builders in this phase of 
regulations for the reasons discussed in Section II. Therefore, we are 
not basing any of the final standards for vocational vehicles on 
aerodynamic improvements. Nor would aerodynamic performance be input 
into GEM to demonstrate compliance.
    Weight Reduction: NHTSA and EPA are also not basing any of the 
final vocational vehicle standards on use of vehicle weight reduction. 
Thus, vehicle mass reductions are not an input into GEM. The agencies 
are taking this approach despite comments suggesting that the agencies 
make use of weight reductions for this segment, because we are unable 
to quantify the potential impact of weight reduction on vehicle utility 
in this broad segment. Vocational vehicles serve an incredibly diverse 
range of functions. Each of these unique vehicle functions is likely to 
have its own unique tradeoff between vehicle utility and the potential 
for vehicle mass reduction. The agencies have not been able at this 
time to determine the degree to which such tradeoffs exist nor the 
specific level of the tradeoff for each unique vehicle vocation. No 
commenter provided data to inform this question. Absent this 
information, the agencies cannot at this time project the potential for 
worthwhile weight reductions from vocational vehicles.
    Drivetrain: Optimization of vehicle gearing to engine performance 
through selection of transmission gear ratios, final drive gear ratios 
and tire size can play a significant role in reducing fuel consumption 
and GHGs. Optimization of gear selection versus vehicle and engine 
speed accomplished through driver training or automated transmission 
gear selection can provide additional reductions. The 2010 NAS report 
found that the opportunities to reduce fuel consumption in heavy-duty 
vehicles due to transmission and driveline technologies in the 2015 
time frame ranged between 2 and 8 percent.\273\ Initially, the agencies 
considered reflecting transmission choices and technology in our 
standard setting process for both tractors and vocational vehicles (see 
previous discussion above on automated manual and automatic 
transmissions for tractors). We have however decided not to do so for 
the following reasons.
---------------------------------------------------------------------------

    \273\ See 2010 NAS Report, Note 197, pp 134 and 137.
---------------------------------------------------------------------------

    The primary factors that determine optimum gear selection are 
vehicle weight, vehicle aerodynamics, vehicle speed, and engine 
performance typically considered on a two dimensional map of engine 
speed and torque. For a given power demand (determined by speed, 
aerodynamics and vehicle mass) an optimum transmission and gearing 
setup will keep the engine power delivery operating at the best speed 
and torque points for highest engine

[[Page 57230]]

efficiency. Since power delivery from the engine is the product of 
speed and torque a wide range of torque and speed points can be found 
that deliver adequate power, but only a smaller subset will provide 
power with peak efficiency. Said more generally, the design goal is for 
the transmission to deliver the needed power to the vehicle while 
maintaining engine operation within the engine's ``sweet spot'' for 
most efficient operation. Absent information about vehicle mass and 
aerodynamics (which determines road load at highway speeds) it is not 
possible to optimize the selection of gear ratios for lowest fuel 
consumption. Truck and chassis manufacturers today offer a wide range 
of tire sizes, final gear ratios and transmission choices so that final 
bodybuilders can select an optimal combination given the finished 
vehicle weight, general aerodynamic characteristics and expected 
average speed. In order to set fuel efficiency and GHG standards that 
would reflect these optimizations, the agencies would need to regulate 
a wide range of small entities that are final bodybuilders, would need 
to set a large number of uniquely different standards to reflect the 
specific weight and aerodynamic differences and finally would need test 
procedures to evaluate these differences that would not themselves be 
excessively burdensome. Finally, the agencies would need the underlying 
data regarding effectively all of the vocational trucks produced today 
in order to determine the appropriate standards. Because the market is 
already motivated to reach these optimizations themselves today, 
because we have insufficient data to determine appropriate standards, 
and finally, because we believe the testing burden would be 
unjustifiably high, we are not finalizing to reflect transmission and 
gear ratio optimization in our GEM or in our standard setting.
    Some commenters suggested that the agencies predicate the 
vocational vehicle standard on the use of specific transmission 
technologies for example automated manual transmissions believing that 
these mechanically more efficient designs would inherently provide 
better fuel efficiency and lower greenhouse gas emissions than 
conventional torque convertor automatic transmission designs. However 
as discussed above the agencies believe that the small mechanical 
efficiency differences between these transmission designs are 
relatively insignificant in the context of the dominant impact of 
proper gear ratio selection in determining a vehicle's overall 
performance. In many cases, the mechanically more efficient design may 
prove less effective in use if other aspects of vehicle performance 
(such a vehicle launch under load) compromise the selection of gear 
ratios. This somewhat surprising outcome can be seen most readily by 
looking at modern passenger cars where mechanically less efficient 
torque converter automatic models often produce equal or better fuel 
economy when compared to the more mechanically efficient manual 
transmission versions of the same vehicles. Given this reality, we do 
not believe it would be appropriate to base the vocational truck 
standard on the use of a particular transmission technology. In the 
future, if we develop a complete vehicle chassis test approach to 
regulating this segment, we would then be able to incorporate 
transmission performance as we already do for the heavy-duty pickup 
truck and van segment.
    Idle Reduction: Episodic idling by vocational vehicles occurs 
during the workday, unlike the overnight idling of combination tractors 
(see discussion in Section III.A.2.a). Vocational vehicle idling can be 
divided into two typical types. The first type is idling while 
waiting--such as during a pickup or delivery. This type of idling can 
be reduced through automatic engine shut-offs. The second type of 
idling is to accomplish PTO operation, such as compacting garbage or 
operating a bucket. The agencies have found only one study that 
quantifies the emissions due to idling conducted by Argonne National 
Lab based on 2002 VIUS data.\274\ EPA conducted a work assignment to 
assist in characterizing PTO operations. The study of a utility truck 
used in two different environments (rural and urban) and a refuse 
hauler found that the PTO operated on average 28 percent of time 
relative to the total time spent driving and idling.\275\ The use of 
hybrid powertrains to reduce idling is discussed below.
---------------------------------------------------------------------------

    \274\ Gaines, Linda, A. Vyas, J. Anderson (Argonne National 
Laboratory). Estimation of Fuel Use by Idling Commercial Trucks. 
January 2006.
    \275\ Southwest Research Institute. Power Take Off Cycle 
Development and Testing. 2010. Docket EPA-HQ-OAR-2010-0162-3335.
---------------------------------------------------------------------------

    Hybrid Powertrains: Several types of vocational vehicles are well 
suited for hybrid powertrains. Vehicles such as utility or bucket 
trucks, delivery vehicles, refuse haulers, and buses have operational 
usage patterns with either a significant amount of stop-and-go activity 
or spend a large portion of their operating hours idling the main 
engine to operate a PTO unit. The industry is currently developing many 
variations of hybrid powertrain systems. The hybrids developed to date 
have seen fuel consumption and CO2 emissions reductions 
between 20 and 50 percent in the field. However, there are still some 
key issues that are restricting the penetration of hybrids, including 
overall system cost, battery technology, and lack of cost-effective 
electrified accessories. We have not predicated the standards based on 
the use of hybrids reflecting the still nascent level of technology 
development and the very small fraction of vehicle sales they would be 
expected to account for in this time frame--on the order of only a 
percent or two. Were we to overestimate the number of hybrids that 
could be produced, we would set a standard that is not feasible. We 
believe that it is more appropriate given the status of technology 
development and our hopes for future advancements in hybrid 
technologies to encourage their production through incentives. Thus, to 
create an incentive for early introduction of hybrid powertrains into 
the vocational vehicle fleet, the agencies are adopting the proposed 
advanced technology credits if hybrid powertrains are used as a 
technology to meet the vocational vehicle standard (or any other 
vehicle standard), as described in Section IV.
(b) Gasoline Engine Technologies
    The gasoline (or spark ignited) engines certified and sold as loose 
engines into the heavy-duty truck market are typically large V8 and V10 
engines produced by General Motors and Ford. The basic architecture of 
these engines is the same as the versions used in the heavy-duty pickup 
trucks and vans. Therefore, the technologies analyzed by the agencies 
mirror the gasoline engine technologies used in the heavy-duty pickup 
truck analysis in Section III.B above.
    Building on the technical analysis underlying the light-duty 2012-
2016 MY vehicle rule, the agencies took a fresh look at technology 
effectiveness values for purposes of this analysis using as a starting 
point the estimates from that rule. The agencies then considered the 
impact of test procedures (such as higher test weight of HD pickup 
trucks and vans) on the effectiveness estimates. The agencies also 
considered other sources such as the 2010 NAS Report, recent CAFE 
compliance data, and confidential manufacturer estimates of technology 
effectiveness. NHTSA and EPA engineers reviewed effectiveness 
information from the multiple sources for each technology and ensured 
that such effectiveness estimates were based

[[Page 57231]]

on technology hardware consistent with the BOM components used to 
estimate costs.
    The agencies note that the effectiveness values estimated for the 
technologies may represent average values, and do not reflect the 
potentially-limitless spectrum of possible values that could result 
from adding the technology to different vehicles. For example, while 
the agencies have estimated an effectiveness of 0.5 percent for low 
friction lubricants, each vehicle could have a unique effectiveness 
estimate depending on the baseline vehicle's oil viscosity rating. For 
purposes of this final rulemaking, NHTSA and EPA believe that employing 
average values for technology effectiveness estimates is an appropriate 
way of recognizing the potential variation in the specific benefits 
that individual manufacturers (and individual engines) might obtain 
from adding a fuel-saving technology.
    Baseline Engine: Similar to the gasoline engine used as the 
baseline in the light-duty rule, the agencies assumed the baseline 
engine in this segment to be a naturally aspirated, overhead valve V8 
engine.\276\ The agencies did not receive any comments regarding the 
baseline engine assumptions in the proposal. The following discussion 
of effectiveness is generally in comparison to 2010 baseline engine 
performance.
---------------------------------------------------------------------------

    \276\ The agencies note that baseline did not include coupled 
cam phasing for loose HD gasoline engines. The HD loose engines are 
slightly different than the ones used in the HD pickup trucks. They 
tend to be the older versions of the same engine.
---------------------------------------------------------------------------

    For the final rulemaking, the agencies considered the same set of 
technologies for loose gasoline engines at proposal. The agencies 
received comments which suggested that the agencies consider 
electrification of accessories to reduce the fuel consumption and 
CO2 emissions from heavy-duty gasoline engines. 
Electrification may result in a reduction in power demand, because 
electrically powered accessories (such as the air compressor or power 
steering) operate only when needed if they are electrically powered, 
but they impose a parasitic demand all the time if they are engine 
driven. In other cases, such as cooling fans or an engine's water pump, 
electric power allows the accessory to run at speeds independent of 
engine speed, which can reduce power consumption. However, technologies 
such as these improvements to accessories are not demonstrated using 
the engine dynamometer test procedures being adopted in this final rule 
because those systems are not installed on the engine during the 
testing. Thus, the technologies the agencies considered include the 
following:
    Engine Friction Reduction: In addition to low friction lubricants, 
manufacturers can also reduce friction and improve fuel consumption by 
improving the design of engine components and subsystems. Examples 
include improvements in low-tension piston rings, piston skirt design, 
roller cam followers, improved crankshaft design and bearings, material 
coatings, material substitution, more optimal thermal management, and 
piston and cylinder surface treatments. The 2010 NAS, NESCCAF \277\ and 
EEA \278\ reports as well as confidential manufacturer data used in the 
light-duty vehicle rulemaking suggested a range of effectiveness for 
engine friction reduction to be between 1 to 3 percent. NHTSA and EPA 
continue to believe that this range is accurate.
---------------------------------------------------------------------------

    \277\ Northeast States Center for a Clean Air Future. ``Reducing 
Greenhouse Gas Emissions from Light-Duty Motor Vehicles.'' September 
2004.
    \278\ Energy and Environmental Analysis, Inc. ``Technology to 
Improve the Fuel Economy of Light Duty Trucks to 2015.'' May 2006.
---------------------------------------------------------------------------

    Coupled Cam Phasing: Valvetrains with coupled (or coordinated) cam 
phasing can modify the timing of both the inlet valves and the exhaust 
valves an equal amount by phasing the camshaft of a single overhead cam 
engine or an overhead valve engine. Based on the light-duty 2012-2016 
MY vehicle rule, previously-received confidential manufacturer data, 
and the NESCCAF report, NHTSA and EPA estimated the effectiveness of 
couple cam phasing CCP to be between 1 and 4 percent. NHTSA and EPA 
reviewed this estimate for purposes of the NPRM, and continue to find 
it accurate.
    Cylinder Deactivation: In conventional spark-ignited engines 
throttling the airflow controls engine torque output. At partial loads, 
efficiency can be improved by using cylinder deactivation instead of 
throttling. Cylinder deactivation can improve engine efficiency by 
disabling or deactivating (usually) half of the cylinders when the load 
is less than half of the engine's total torque capability--the valves 
are kept closed, and no fuel is injected--as a result, the trapped air 
within the deactivated cylinders is simply compressed and expanded as 
an air spring, with reduced friction and heat losses. The active 
cylinders combust at almost double the load required if all of the 
cylinders were operating. Pumping losses are significantly reduced as 
long as the engine is operated in this ``part cylinder'' mode. 
Effectiveness improvements scale roughly with engine displacement-to-
vehicle weight ratio: The higher displacement-to-weight vehicles, 
operating at lower relative loads for normal driving, have the 
potential to operate in part-cylinder mode more frequently. Cylinder 
deactivation is less effective on heavily-loaded vehicles because they 
require more power and spend less time in areas of operation where only 
partial power is required. The technology also requires proper 
integration into the vehicles which is difficult in the vocational 
vehicle segment where often the engine is sold to a chassis 
manufacturer or body builder without knowing the type of transmission 
or axle used in the vehicle or the precise duty cycle of the vehicle. 
The cylinder deactivation requires fine tuning of the calibration as 
the engine moves into and out of deactivation mode to achieve 
acceptable NVH. Additionally, cylinder deactivation would be difficult 
to apply to vehicles with a manual transmission because it requires 
careful gear change control. NHTSA and EPA adjusted the 2012-16 MY 
light-duty rule estimates using updated power to weight ratings of 
heavy-duty trucks and confidential business information and downwardly 
adjusted the effectiveness to 0 to 3 percent for these vehicles to 
reflect the differences in drive cycle and operational opportunities 
compared to light-duty vehicles. Because of the complexities associated 
with integrating cylinder deactivation in a non-integrated vehicle 
assembly process and the low effectiveness of the technology, the 
agencies did not include cylinder deactivation in the final gasoline 
engine technology package.
    Stoichiometric gasoline direct injection: SGDI (also known as 
spark-ignition direct injection engines) inject fuel at high pressure 
directly into the combustion chamber (rather than the intake port in 
port fuel injection). Direct injection of the fuel into the cylinder 
improves cooling of the air/fuel charge within the cylinder, which 
allows for higher compression ratios and increased thermodynamic 
efficiency without the onset of combustion knock. Recent injector 
design advances, improved electronic engine management systems and the 
introduction of multiple injection events per cylinder firing cycle 
promote better mixing of the air and fuel, enhance combustion rates, 
increase residual exhaust gas tolerance and improve cold start 
emissions. SGDI engines achieve higher power density and match well 
with other technologies, such as boosting and variable valvetrain 
designs. The light-duty 2012-2016 MY vehicle rule estimated the 
effectiveness

[[Page 57232]]

of SGDI to be between 2 and 3 percent. NHTSA and EPA revised these 
estimated accounting for the use and testing methods for these vehicles 
along with confidential business information estimates received from 
manufacturers while developing the program. Based on these revisions, 
NHTSA and EPA estimate the range of 1 to 2 percent for SGDI.
(c) Diesel Engine Technologies
    Different types of diesel engines are used in vocational vehicles, 
depending on the application. They fall into the categories of Light, 
Medium, and Heavy Heavy-duty Diesel engines. The Light Heavy-duty 
Diesel engines typically range between 4.7 and 6.7 liters displacement. 
The Medium Heavy-duty Diesel engines typically have some overlap in 
displacement with the Light Heavy-duty Diesel engines and range between 
6.7 and 9.3 liters. The Heavy Heavy-duty Diesel engines typically are 
represented by engines between 10.8 and 16 liters.
    Baseline Engine: There are three baseline diesel engines, a Light, 
Medium, and a Heavy Heavy-duty Diesel engine. The agencies developed 
the baseline diesel engine as a 2010 model year engine with an 
aftertreatment system which meets EPA's 0.2 grams of NOX/
bhp-hr standard with an SCR system along with EGR and meets the PM 
emissions standard with a diesel particulate filter with active 
regeneration. The engine is turbocharged with a variable geometry 
turbocharger. As noted above in Section III.A.1.b, the agencies 
received comments from Navistar stating that the agencies used an 
artificially low baseline CO2 emissions level which was 
tilted toward the use of SCR aftertreatment system. As discussed in 
Section III.A.1.b, the agencies disagree with the statement that SCR is 
infeasible. Additional responses from the agencies are available in the 
Response to Comments document, Section 6.2.\279\ The following 
discussion of technologies describes improvements over the 2010 model 
year baseline engine performance, unless otherwise noted. Further 
discussion of the baseline engine and its performance can be found in 
Section III.C.2.(c)(i) below. The following discussion of effectiveness 
is generally in comparison to 2010 baseline engine performance, and is 
in reference to performance in terms of the Heavy-duty FTP that would 
be used for compliance for these engine standards. This is in 
comparison to the steady state SET procedure that would be used for 
compliance purposes for the engines used in Class 7 and 8 tractors. See 
Section II.B.2.(i) above.
---------------------------------------------------------------------------

    \279\ U.S. EPA. Greenhouse Gas Emissions Standards and Fuel 
Efficiency Standards for Medium- and Heavy-Duty Engines and 
Vehicles--EPA Response to Comments Document for Joint Rulemaking. 
EPA-420-R-11-004. Docket EPA-HQ-OAR-2010-0162.
---------------------------------------------------------------------------

    Turbochargers: Improved efficiency of a turbocharger compressor or 
turbine could reduce fuel consumption by approximately 1 to 2 percent 
over today's variable geometry turbochargers in the market today. The 
2010 NAS report identified technologies such as higher pressure ratio 
radial compressors, axial compressors, and dual stage turbochargers as 
design paths to improve turbocharger efficiency.
    Low Temperature Exhaust Gas Recirculation: Most LHDD, MHDD, and 
HHDD engines sold in the U.S. market today use cooled EGR, in which 
part of the exhaust gas is routed through a cooler (rejecting energy to 
the engine coolant) before being returned to the engine intake 
manifold. EGR is a technology employed to reduce peak combustion 
temperatures and thus NOX. Low-temperature EGR uses a larger 
or secondary EGR cooler to achieve lower intake charge temperatures, 
which tend to further reduce NOX formation. If the 
NOX requirement is unchanged, low-temperature EGR can allow 
changes such as more advanced injection timing that will increase 
engine efficiency slightly more than one percent. Because low-
temperature EGR reduces the engine's exhaust temperature, it may not be 
compatible with exhaust energy recovery systems such as 
turbocompounding or a bottoming cycle.
    Engine Friction Reduction: Reduced friction in bearings, valve 
trains, and the piston-to-liner interface will improve efficiency. Any 
friction reduction must be carefully developed to avoid issues with 
durability or performance capability. Estimates of fuel consumption 
improvements due to reduced friction range from 0.5 to 1.5 
percent.\280\
---------------------------------------------------------------------------

    \280\ See TIAX, Note 198, pg. 4-15.
---------------------------------------------------------------------------

    Selective catalytic reduction: This technology is common on 2010 
heavy-duty diesel engines. Because SCR is a highly effective 
NOX aftertreatment approach, it enables engines to be 
optimized to maximize fuel efficiency, rather than minimize engine-out 
NOX. 2010 SCR systems are estimated to result in improved 
engine efficiency of approximately 4 to 5 percent compared to a 2007 
in-cylinder EGR-based emissions system and by an even greater 
percentage compared to 2010 in-cylinder approaches.\281\ As more 
effective low-temperature catalysts are developed, the NOX 
conversion efficiency of the SCR system will increase. Next-generation 
SCR systems could then enable still further efficiency improvements; 
alternatively, these advances could be used to maintain efficiency 
while down-sizing the aftertreatment. We estimate that continued 
optimization of the catalyst could offer 1 to 2 percent reduction in 
fuel use over 2010 model year systems in the 2014 model year.\282\ The 
agencies also estimate that continued refinement and optimization of 
the SCR systems could provide an additional 2 percent reduction in the 
2017 model year.
---------------------------------------------------------------------------

    \281\ Stanton, D. ``Advanced Diesel Engine Technology 
Development for High Efficiency, Clean Combustion.'' Cummins, Inc. 
Annual Progress Report 2008 Vehicle Technologies Program: Advanced 
Combustion Engine Technologies, U.S. Department of Energy. Pp 113-
116. December 2008.
    \282\ See TIAX, Note 198, pg. 4-9
---------------------------------------------------------------------------

    Improved Combustion Process: Fuel consumption reductions in the 
range of 1 to 4 percent are identified in the 2010 NAS report through 
improved combustion chamber design, higher fuel injection pressure, 
improved injection shaping and timing, and higher peak cylinder 
pressures.\283\
---------------------------------------------------------------------------

    \283\ See 2010 NAS Report, Note 197, page 56.
---------------------------------------------------------------------------

    Reduced Parasitic Loads: Accessories that are traditionally gear or 
belt driven by a vehicle's engine can be optimized and/or converted to 
electric power. Examples include the engine water pump, oil pump, fuel 
injection pump, air compressor, power-steering pump, cooling fans, and 
the vehicle's air-conditioning system. Optimization and improved 
pressure regulation may significantly reduce the parasitic load of the 
water, air and fuel pumps. Electrification may result in a reduction in 
power demand, because electrically powered accessories (such as the air 
compressor or power steering) operate only when needed if they are 
electrically powered, but they impose a parasitic demand all the time 
if they are engine driven. In other cases, such as cooling fans or an 
engine's water pump, electric power allows the accessory to run at 
speeds independent of engine speed, which can reduce power consumption. 
The TIAX study used 2 to 4 percent fuel consumption improvement for 
accessory electrification, with the understanding that electrification 
of accessories will have more effect in short-haul/urban applications 
and less benefit in line-haul applications.\284\
---------------------------------------------------------------------------

    \284\ See TIAX. Note 198, Pages 3-5.

---------------------------------------------------------------------------

[[Page 57233]]

(2) What is the projected technology package's effectiveness and cost?
(a) Vocational Vehicles
(i) Baseline Vocational Vehicle Performance
    The baseline vocational vehicle model is defined in the GEM, as 
described in RIA Chapter 4.4.6. At proposal, the agencies used a 
baseline rolling resistance coefficient for today's vocational vehicle 
fleet of 9.0 kg/metric ton.\285\ As discussed in Section II.D.1, the 
agencies conducted a tire rolling resistance evaluation of tires used 
in vocational vehicles. The agencies found that the average rolling 
resistance of the tires was lower than the agencies' assessment at 
proposal. Based on this new information and our understanding of the 
potential to improve tire rolling resistance by 2014, the agencies are 
setting the vocational truck standard premised on the use of tires with 
a rolling resistance coefficient of 7.7 kg/metric ton. This value is 
consistent with the average performance of the subset of tires the 
agencies tested. We are projecting this standard will drive a 5 percent 
reduction in tire rolling resistance on average across the fleet. We 
are projecting this 5 percent reduction based on our expectation that 
manufacturers will desire to bring all of their tires below the 
standard (not just comply on average) and knowing manufacturers will 
need some degree of overcompliance to ensure despite manufacturing 
variability and test to test variability their products are compliant 
with the emission standards. In order to reflect both this tighter 
standard (based on 7.7) and the 5 percent reduction in rolling 
resistance we project it will accomplish, we are modeling the baseline 
performance of vocational truck tires as 8.1 kg/metric ton.
---------------------------------------------------------------------------

    \285\ The baseline tire rolling resistance for this segment of 
vehicles was derived for the proposal based on the current baseline 
tractor and passenger car tires. The baseline tractor drive tire has 
a rolling resistance of 8.2 kg/metric ton based on SmartWay testing. 
The average passenger car has a tire rolling resistance of 9.75 kg/
metric ton based on a presentation made to CARB by the Rubber 
Manufacturer's Association. As noted above, further analysis has 
resulted in an estimate of improved performance in the baseline 
fleet, which is based entirely on use of LRR tires on vocational 
vehicles (not cars). Additional details are available in the RIA 
chapter 2.
---------------------------------------------------------------------------

    Further vehicle technology is not included in this baseline, as 
discussed below in the discussion of the baseline vocational vehicle. 
The baseline engine fuel consumption represents a 2010 model year 
diesel engine, as described in RIA Chapter 4. Using these values, the 
baseline performance of these vehicles is included in Table III-12.
    The agencies note that the baseline performance derived for the 
final rule slightly differs from the values derived for the NPRM. The 
first difference is due to the change in rolling resistance from 9.0 to 
8.1 kg/metric ton based on the agencies' post-proposal test results. 
Second, there are minor differences in the fuel consumption and 
CO2 emissions due to the small modifications made to the 
GEM, as noted in RIA Chapter 4. In addition, the HHD vocational vehicle 
baseline performance for the final rule uses a revised payload 
assumption from 38,000 to 15,000 pounds, as described in Section 
II.D.3.c.iii.

          Table III-12--Baseline Vocational Vehicle Performance
------------------------------------------------------------------------
                                           Vocational vehicle
------------------------------------------------------------------------
                                              Medium heavy- Heavy  heavy-
                                 Heavy-duty       duty          duty
------------------------------------------------------------------------
Fuel Consumption Baseline               40.0          24.3          23.2
 (gallon/1,000 ton-mile)......
CO2 Baseline (grams CO2/ton-           408           247           236
 mile)........................
------------------------------------------------------------------------

(ii) Vocational Vehicle Technology Package
    The final program for vocational vehicles for this phase of 
regulatory standards is based on the performance of tire and engine 
technologies. Aerodynamics technology, weight reduction, drive train 
improvement, and hybrid power trains are not included for the reasons 
discussed above in Section III.C (1) and Section II.D.
    The assessment of the final technology effectiveness was developed 
through the use of the GEM. To account for the two final engine 
standards, EPA is finalizing the use of a 2014 model year fuel 
consumption map in the GEM to derive the 2014 model year truck standard 
and a 2017 model year fuel consumption map to derive the 2017 model 
year truck standard. (These fuel consumption maps reflect the main 
standards for HD diesel engines, not the alternative engine standards.) 
The agencies estimate that the rolling resistance of 50 percent of the 
tires can be reduced by 10 percent in the 2014 model year, for an 
overall reduction in rolling resistance of 5 percent. The vocational 
vehicle standards for all three regulatory categories were determined 
using a tire rolling resistance coefficient of 7.7 kg/metric ton in the 
2014 model year. The set of input parameters which are modeled in GEM 
are shown in Table III-13.

                         Table III-13--GEM Inputs for Final Vocational Vehicle Standards
----------------------------------------------------------------------------------------------------------------
                                                                       2014 MY                   2017 MY
----------------------------------------------------------------------------------------------------------------
Engine......................................................   2014 MY 7L for LHD/MHD    2017 MY 7L for LHD/MHD
                                                               and 15L for HHD Trucks   and 15L for HHD Trucks.
Tire Rolling Resistance (kg/metric ton).....................                      7.7                       7.7
----------------------------------------------------------------------------------------------------------------

    The agencies developed the final standards by using the engine and 
tire rolling resistance inputs in the GEM, as shown in Table III-13. 
The percent reductions shown in Table III-14 reflect improvements over 
the 2010 model year baseline vehicle with a 2010 model year baseline 
engine.

[[Page 57234]]



                     Table III-14--Final Vocational Vehicle Standards and Percent Reductions
----------------------------------------------------------------------------------------------------------------
                                                                                Vocational vehicle
                                                                 -----------------------------------------------
                                                                   Light heavy-    Medium heavy-   Heavy heavy-
                                                                       duty            duty            duty
----------------------------------------------------------------------------------------------------------------
2016 MY Fuel Consumption Standard (gallon/1,000 ton-mile).......            38.1            23.0            22.2
2017 MY Fuel Consumption Standard (gallon/1,000 ton-mile).......            36.7            22.1            21.8
2014 MY CO2 Standard (grams CO2/ton-mile).......................             388             234             226
2017 MY CO2 Standard (grams CO2/ton-mile).......................             373             225             222
Percent Reduction from 2010 baseline in 2014 MY.................              5%              5%              4%
Percent Reduction from 2010 baseline in 2017 MY.................              8%              9%              6%
----------------------------------------------------------------------------------------------------------------

(iii) Technology Package Cost
    The agencies did not receive any substantial comments on the engine 
costs proposed. Thus the agencies are projecting the costs of the 
technologies used to develop the final standards based on the costs 
used in the proposal, but revised to reflect 2009$, new ICMs, and a 50 
percent penetration rate of low rolling resistance tires (as explained 
above). EPA and NHTSA developed the costs of LRR tires based on the ICF 
report. The estimated cost per truck is $81 (2009$) for LHD and MHD 
trucks and $97 (2009$) for HHD trucks. These costs include a low 
complexity ICM of 1.18 and are applicable in the 2014 model year.
(iv) Reasonableness of the Final Vocational Vehicle Standards
    The final standards would not only add only a small amount to the 
vehicle cost, but are highly cost effective, an estimated $20 ton of 
CO2eq per vehicle in 2030.\286\ This is even less than the 
estimated cost effectiveness for CO2eq removal under the 
light-duty vehicle rule, already considered by the agencies to be a 
highly cost effective reduction.\287\ Moreover, the modest cost of 
controls is recovered almost immediately due to the associated fuel 
savings, as shown in the payback analysis included in Table VIII-7. 
Given that the standards are technically feasible within the lead time 
afforded by the 2014 model year, are inexpensive and highly cost 
effective, and do not have other adverse potential impacts (e.g., there 
are no projected negative impacts on safety or vehicle utility), the 
final standards represent a reasonable choice under section 202(a) of 
the CAA and NHTSA's EISA authority under 49 U.S.C. 32902(k)(2), and the 
agencies believe that the standards are consistent with their 
respective authorities. Based on the discussion above, NHTSA believes 
these standards are the maximum feasible under EISA.
---------------------------------------------------------------------------

    \286\ See Section VIII.D.
    \287\ As noted above, the light-duty rule had an estimated cost 
per ton of $50 when considering the vehicle program costs only and a 
cost of -$210 per ton considering the vehicle program costs along 
with fuel savings in 2030. See 75 FR 25515, Table III.H.3-1.
---------------------------------------------------------------------------

(v) Alternative Vehicle Standards Considered
    The agencies are not finalizing vehicle standards less stringent 
than the final standards because the agencies believe these standards 
are highly cost effective, as just explained.
    The agencies considered finalizing truck standards which are more 
stringent reflecting the inclusion of hybrid powertrains in those 
vocational vehicles where use of hybrid powertrains is appropriate. The 
agencies estimate that a 25 percent utilization rate of hybrid 
powertrains in MY 2017 vocational vehicles would add, on average, 
$30,000 to the cost of each vehicle and more than double the cost of 
the rule for this sector. See the RIA at chapter 6.1.8. The emission 
reductions associated with these very high costs appear to be modest. 
See the RIA Table 6-14. In addition, the agencies are finalizing 
flexibilities in the form of generally applicable credit opportunities 
for advanced technologies, to encourage use of hybrid powertrains. See 
Section IV.C. 2 below. Several commenters recommended that in addition 
to hybrid powertrains, the agencies consider setting more stringent 
standards based on the use of aerodynamic improvements, weight 
reduction, idle shutdown technologies, vehicle speed limiters, and 
specific transmission technologies. As described above, we are not 
finalizing standards based on these technologies for reasons that 
related to the unique nature of the very diverse vocational vehicle 
segment. At this time, the agencies have no means to determine the 
current baseline aerodynamic performance of all vocational vehicles 
(ranging from concrete mixers to school buses), nor a means to project 
to what degree the aerodynamic performance could be improved without 
compromising the utility of the vehicle. Absent this information, the 
agencies cannot set a standard based on improvements in aerodynamic 
performance. The agencies face similar obstacles regarding our ability 
to project the utility tradeoffs that may exist between limitations on 
vehicle speed or reductions in vehicle mass and utility and safety of 
vocational vehicles. We are confident the answer to those questions 
will differ for a school bus compared to a concrete mixer compared to a 
fire truck compared to an ambulance. Absent an approach to set distinct 
standards for each of the vocational vehicle types and the information 
necessary to determine the appropriate level of performance for those 
vehicles, the agencies cannot set standards for vocational vehicles 
based on the use of these technologies. For these reasons, the agencies 
are not adopting more comprehensive standards for vocational vehicles. 
The agencies do agree that at least some vocational vehicles can be 
made more efficient through the use of technologies, including those 
technologies mentioned in the comments, and the agencies fully intend 
to take on the challenge of developing the data, test procedures and 
regulatory structures necessary to set more comprehensive standards for 
vocational trucks in the future.
(b) Gasoline Engines
(i) Baseline Gasoline Engine Performance
    EPA and NHTSA developed the reference heavy-duty gasoline engines 
to represent a 2010 model year engine compliant with the 0.20 g/bhp-hr 
NOX standard for on-highway heavy-duty engines.
    NHTSA and EPA developed the baseline fuel consumption and 
CO2 emissions for the gasoline engines from manufacturer 
reported CO2 values used in the certification of non-GHG 
pollutants. The baseline engine for the analysis was developed to 
represent a 2011 model year engine, because this is the most current 
information available. The average CO2 performance of the 
heavy-duty gasoline engines was 660 g/bhp-hour, which will be used as a

[[Page 57235]]

baseline. The baseline gasoline engines are all stoichiometric port 
fuel injected V-8 engines without cam phasers or other variable valve 
timing technologies. While they may reflect some degree of static valve 
timing optimization for fuel efficiency they do not reflect the 
potential to adjust timing with engine speed.
(ii) Gasoline Engine Technology Package Effectiveness
    The gasoline engine technology package includes engine friction 
reduction, coupled cam phasing, and SGDI to produce an overall five 
percent reduction from the reference engine based on the Heavy-duty 
Lumped Parameter model. The agencies are projecting a 100 percent 
application rate of this technology package to the heavy-duty gasoline 
engines, which results in a CO2 standard of 627 g/bhp-hr and 
a fuel consumption standard of 7.05 gallon/100 bhp-hr. As discussed in 
Section II.D.b.ii, the agencies are adopting gasoline engine standards 
that begin in the 2016 model year based on the agencies' projection of 
the engine redesign schedules for the small number of engines in this 
category.
(iii) Gasoline Engine Technology Package Cost
    For the proposed costs, the agencies considered both the direct or 
``piece'' costs and indirect costs of individual components of 
technologies. For the direct costs, the agencies followed a BOM 
approach employed by NHTSA and EPA in the light-duty 2012-2016 MY 
vehicle rule. In this final action, the agencies are using marked up 
gasoline engine technology costs developed for the HD Pickup Truck and 
Van segment because these engines are made by the same manufacturers 
(primarily by Ford and GM) and are simply, sold as loose engines rather 
than as complete vehicles. Hence the engine cost estimates are 
fundamentally the same. The agencies did not receive any comments 
recommending adjustments to the proposed gasoline engine technology 
costs. The costs summarized in Table III-15 are consistent with the 
proposed values, but updated to reflect 2009$ and new ICMs. The costs 
shown in Table III-15 include a low complexity ICM of 1.24 and are 
applicable in the 2016 model year. No learning effects are applied to 
engine friction reduction costs, while flat-portion of the curve 
learning is considered applicable to both coupled cam phasing and SGDI.


 Table III-15--Heavy-Duty Gasoline Engine Technology Costs Inclusive of
                          Indirect Cost Markups
                                 [2009$]
------------------------------------------------------------------------
                                                                2016 MY
------------------------------------------------------------------------
Engine Friction Reduction....................................        $95
Coupled Cam Phasing..........................................         46
Stoichiometric Gas Direct Injection..........................        452
                                                              ----------
    Total....................................................        594
------------------------------------------------------------------------

(iv) Reasonableness of the Final Standard
    The final engine standards are reasonable and consistent with the 
agencies' respective authorities. With respect to the 2016 MY standard, 
all of the technologies on which the standards are predicated have been 
demonstrated and their effectiveness is well documented. The final 
standards reflect a 100 percent application rate for these 
technologies. The costs of adding these technologies remain modest 
across the various engine classes as shown in Table 0-15. Use of these 
technologies would add only a small amount to the cost of the 
vehicle,\288\ and the associated reductions are highly cost effective, 
an estimated $20 per ton of CO2eq per vehicle.\289\ This is 
even more cost effective than the estimated cost effectiveness for 
CO2eq removal and fuel economy improvement under the light-
duty vehicle rule, already considered by the agencies to be a highly 
cost effective reduction.\290\ Accordingly, EPA and NHTSA view these 
standards as reflecting an appropriate balance of the various statutory 
factors under section 202(a) of the CAA and under NHTSA's EISA 
authority at 49 U.S.C. 32902(k)(2). Based on the discussion above, 
NHTSA believes these standards are the maximum feasible under EISA.
---------------------------------------------------------------------------

    \288\ Sample 2010 MY vocational vehicles range in price between 
$40,000 for a Class 4 work truck to approximately $200,000 for a 
Class 8 refuse hauler. See pages 16-17 of ICF's ``Investigation of 
Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-
Duty On-Road Vehicles.'' July 2010.
    \289\ See Vocational Vehicle CO2 savings and 
technology costs in Table 7-4 in RIA chapter 7.
    \290\ The light-duty rule had an estimated cost per ton of $50 
when considering the vehicle program costs only and a cost of -$210 
per ton considering the vehicle program costs along with fuel 
savings in 2030. See 75 FR 25515, Table III.H.3-1.
---------------------------------------------------------------------------

    Several commenters suggested that the lead time provided by the 
agencies for heavy-duty pickups and vans and by extension the 2016 
gasoline engine standards were unnecessarily long. The agencies do not 
agree with this assessment. The technologies that we are considering 
here cannot simply be bolted on to an existing engine but can only be 
effectively applied through an integrated design and development 
process. The four years lead time provided here is short in the context 
of engine redesigns and is only possible in part because the standards 
align with engine manufacturers' planned redesign processes that are 
either just starting or will be starting within the year. These 
standards set a clear metric of performance for those planned redesigns 
and we project will lead manufacturers to include a number of 
technologies that would not otherwise have been incorporated into those 
engines.
(v) Alternative Gasoline Engine Standards Considered
    The agencies are not finalizing gasoline standards less stringent 
than the final standards because the agencies believe these standards 
are feasible in the lead time provided, inexpensive, and highly cost 
effective.
    The final rule reflects 100 percent penetration of the technology 
package on whose performance the standard is based, so some additional 
technology would need to be added to obtain further improvements. The 
agencies considered finalizing gasoline engine standards which are more 
stringent reflecting the inclusion of cylinder deactivation and other 
advanced technologies. However, the agencies are not finalizing this 
level of stringency because our assessment is that these technologies 
cannot be adapted to the higher average engine loads of heavy-duty 
vehicles for production by the 2017 model year. We intend to continue 
to evaluate the potential for further gasoline engine improvements 
building on the work done for light-duty passenger cars and trucks as 
we begin work on the next phase of heavy-duty regulations.
(c) Diesel Engines
(i) Baseline Diesel Engine Performance
    EPA and NHTSA developed the baseline heavy-duty diesel engines to 
represent a 2010 model year engine compliant with the 0.20 g/bhp-hr 
NOX standard for on-highway heavy-duty engines.
    The agencies utilized 2007 through 2011 model year CO2 
certification levels from the Heavy-duty FTP cycle as the basis for the 
baseline engine CO2 performance. The pre-2010 data are 
subsequently adjusted to represent 2010 model year engine maps by using 
predefined technologies including SCR and other systems that are being 
used in current 2010 production. The engine CO2 results were 
then sales weighted

[[Page 57236]]

within each regulatory subcategory to develop an industry average 2010 
model year reference engine, as shown in Table III-16. The level of 
CO2 emissions and fuel consumption of these engines varies 
significantly, where the engine with the highest CO2 
emissions is estimated to be 20 percent greater than the sales weighted 
average. Details of this analysis are included in RIA Chapter 2.

 Table III-16--2010 Model Year Reference Diesel Engine Performance Over
                        the Heavy-Duty FTP Cycle
------------------------------------------------------------------------
                               CO2 emissions  (g/     Fuel consumption
                                     bhp-hr)         (gallon/100 bhp-hr)
------------------------------------------------------------------------
LHD Diesel..................                   630                  6.19
MHD Diesel..................                   630                  6.19
HHD Diesel..................                   584                  5.74
------------------------------------------------------------------------

(ii) Diesel Engine Packages
    The diesel engine technology packages for the 2014 model year 
include engine friction reduction, improved aftertreatment 
effectiveness, improved combustion processes, and low temperature EGR 
system optimization. The improvements in parasitic and friction losses 
come through piston designs to reduce friction, improved lubrication, 
and improved water pump and oil pump designs to reduce parasitic 
losses. The aftertreatment improvements are available through lower 
backpressure of the systems and optimization of the engine-out 
NOX levels. Improvements to the EGR system and air flow 
through the intake and exhaust systems, along with turbochargers can 
also produce engine efficiency improvements. It should be pointed out 
that individual technology improvements are not additive to each other 
due to the interaction of technologies. The agencies assessed the 
impact of each technology over the Heavy-duty FTP and project an 
overall cycle improvement in the 2014 model year of 3 percent for HHD 
diesel engines and 5 percent for LHD and MHD diesel engines, as 
detailed in RIA Chapter 2.4.2.9 and 2.4.2.10. EPA used a 100 percent 
application rate of this technology package to determine the level of 
the final 2014 MY standards
    Recently, EPA's heavy-duty highway engine program for criteria 
pollutants provided new emissions standards for the industry in three 
year increments. The heavy-duty engine manufacturer product plans have 
fallen into three year cycles to reflect this environment. EPA is 
finalizing CO2 emission standards recognizing the 
opportunity for technology improvements over this time frame while 
reflecting the typical heavy-duty engine manufacturer product plan 
redesign cycles. Thus, the agencies are establishing initial standards 
for the 2014 model year and a more stringent standard for these heavy-
duty engines beginning in the 2017 model year.
    The 2017 model year technology package for LHD and MHD diesel 
engine includes continued development and refinement of the 2014 model 
year technology package, in particular the additional improvement to 
aftertreatment systems. This package leads to a projected 9 percent 
reduction for LHD and MHD diesel engines in the 2017 model year. The 
HHD diesel engine technology packages for the 2017 model year include 
the continued development of the 2014 model year technology package. A 
similar approach to evaluating the impact of individual technologies as 
taken to develop the overall reduction of the 2014 model year package 
was taken with the 2017 model year package. The Heavy-duty FTP cycle 
improvements lead to a 5 percent reduction on the cycle for HHDD, as 
detailed in RIA Chapter 2.4.2.13. The agencies used a 100 percent 
application rate of the technology package to determine the final 2017 
MY standards. The agencies believe that bottom cycling technologies are 
still in the development phase and will not be ready for production by 
the 2017 model year.\291\ Therefore, these technologies were not 
included in determining the stringency of the final standards. However, 
we do believe the bottoming cycle approach represents a significant 
opportunity to reduce fuel consumption and GHG emissions in the future 
for vehicles that operate under primarily steady-state conditions like 
line-haul tractors and some vocational vehicles. As discussed above, we 
also considered setting standards based on the use of hybrid 
powertrains that are a better match to many vocational vehicle duty 
cycles but have decided for the reasons articulated above to not base 
the vocational vehicle standard on the use of hybrid technologies in 
this first regulation. However, EPA and NHTSA are both finalizing 
provisions described in Section IV to create incentives for 
manufacturers to continue to invest to develop these technologies in 
the believe that with further development these technologies can form 
the basis of future standards.
---------------------------------------------------------------------------

    \291\ TIAX noted in their report to the NAS panel that the 
engine improvements beyond 2015 model year included in their report 
are highly uncertain, though they include waste heat recovery in the 
engine package for 2016 through 2020 (page 4-29).
---------------------------------------------------------------------------

    The overall projected improvements in CO2 emissions and 
fuel consumption over the baseline are included in Table III-17.

 Table III-17--Percent Fuel Consumption and CO2 Emission Reductions Over
                        the Heavy-duty FTP Cycle
------------------------------------------------------------------------
                                                          2014     2017
------------------------------------------------------------------------
LHD Diesel............................................       5%       9%
MHD Diesel............................................        5        9
HHD Diesel............................................        3        5
------------------------------------------------------------------------

(iii) Technology Package Costs
    NHTSA and EPA jointly developed costs associated with the engine 
technologies to assess an overall package cost for each regulatory 
category. Our engine cost estimates for diesel engines used in 
vocational vehicles include a separate analysis of the incremental part 
costs, research and development activities, and additional equipment, 
such as emissions equipment to measure N2O emissions. Our 
general approach used elsewhere in this action (for HD pickup trucks, 
gasoline engines, Class 7 and 8 tractors, and Class 2b-8 vocational 
vehicles) estimates a direct manufacturing cost for a part and marks it 
up based on a factor to account for indirect costs. See also 75 FR 
25376. We believe that approach is appropriate when compliance with 
final standards is achieved generally by installing new parts and 
systems purchased from a supplier. In such a case, the supplier is 
conducting the bulk of the research and development on the new parts 
and systems and including those costs in the purchase price paid by the 
original equipment manufacturer. The indirect costs incurred by the 
original equipment manufacturer need not include much cost to cover 
research and development since the bulk of that effort is already done. 
For the MHD and

[[Page 57237]]

HHD diesel engine segment, however, the agencies believe we can make a 
more accurate estimate of technology cost using this alternate approach 
because the primary cost is not expected to be the purchase of parts or 
systems from suppliers or even the production of the parts and systems, 
but rather the development of the new technology by the original 
equipment manufacturer itself. Therefore, the agencies believe it more 
accurate to directly estimate the indirect costs. EPA commonly uses 
this approach in cases where significant investments in research and 
development can lead to an emission control approach that requires no 
new hardware. For example, combustion optimization may significantly 
reduce emissions and cost a manufacturer millions of dollars to develop 
but will lead to an engine that is no more expensive to produce. Using 
a bill of materials approach would suggest that the cost of the 
emissions control was zero reflecting no new hardware and ignoring the 
millions of dollars spent to develop the improved combustion system. 
Details of the cost analysis are included in the RIA Chapter 2. To 
reiterate, we have used this different approach because the MHD and HHD 
diesel engines are expected to comply in large part via technology 
changes that are not reflected in new hardware but rather knowledge 
gained through laboratory and real world testing that allows for 
improvements in control system calibrations--changes that are more 
difficult to reflect through direct costs with indirect cost 
multipliers.
    The agencies developed the engineering costs for the research and 
development of diesel engines with lower fuel consumption and 
CO2 emissions. The aggregate costs for engineering hours, 
technician support, dynamometer cell time, and fabrication of prototype 
parts are estimated at $6.8 million (2009$) per manufacturer per year 
over the five years covering 2012 through 2016. In aggregate, this 
averages out to $284 per engine during 2012 through 2016 using an 
annual sales value of 600,000 light, medium, and heavy heavy-duty 
engines. The agencies received comments from Horriba regarding the 
assumption the agencies used in the proposal that said manufacturers 
would need to purchase new equipment for measuring N2O and 
the associated costs. Horriba provided information regarding the cost 
of stand-alone FTIR instrumentation (estimated at $50,000 per unit) and 
cost of upgrading existing emission measurement systems with NDIR 
analyzers (estimated at $25,000 per unit). The agencies further 
analyzed our assumptions along with Horriba's comments. Thus, we have 
revised the equipment costs estimates and assumed that 75 percent of 
manufacturers would update existing equipment while the other 25 
percent would require new equipment. The agencies are estimating costs 
of $63,087 (2009$) per engine manufacturer per engine subcategory 
(light, medium, and heavy HD) to cover the cost of purchasing photo-
acoustic measurement equipment for two engine test cells. This would be 
a one-time cost incurred in the year prior to implementation of the 
standard (i.e., the cost would be incurred in 2013). In aggregate, this 
averages out to less than $1 per engine in 2013 using an annual sales 
value of 600,000 light, medium, and heavy HD engines.
    EPA also developed the incremental piece cost for the components to 
meet each the 2014 and 2017 standards. These costs shown in Table III-
18 which include a low complexity ICM of 1.15; flat-portion of the 
curve learning is considered applicable to each technology.

   Table III-18--Heavy-Duty Diesel Engine Component Costs Inclusive of
                         Indirect Cost Markups a
                                 [2009$]
------------------------------------------------------------------------
                                    2014 Model year     2017 Model year
------------------------------------------------------------------------
Cylinder Head (flow optimized,    $6 (MHD & HH), $11  $6 (MHD & HHD),
 increased firing pressure,        (LHD).              $10 (LHD).
 improved thermal management).
Exhaust Manifold (flow            $0................  $0.
 optimized, improved thermal
 management).
Turbocharger (improved            $18...............  $17.
 efficiency).
EGR Cooler (improved efficiency)  $4................  $3.
Water Pump (optimized, variable   $91...............  $84.
 vane, variable speed).
Oil Pump (optimized)............  $5................  $4.
Fuel Pump (higher working         $5................  $4.
 pressure, increased efficiency,
 improved pressure regulation).
Fuel Rail (higher working         $10 (MHD & HHD),    $9 (MHD & HHD),
 pressure).                        $12 (LHD).          $11 (LHD).
Fuel Injector (optimized,         $11 (MHD & HHD),    $10 (MHD & HHD),
 improved multiple event           $15 (LHD).          $13 (LHD).
 control, higher working
 pressure).
Piston (reduced friction skirt,   $3................  $3.
 ring and pin).
Aftertreatment system (improved   $0 (MHD & HHD),     $0 (MHD & HHD),
 effectiveness SCR, dosing,        $111 (LHD).         $101 (LHD).
 dpf)a.
Valve Train (reduced friction,    $82 (MHD), $109     $76 (MHD), $101
 roller tappet).                   (LHD).              (LHD).
------------------------------------------------------------------------
Note:
a Note that costs for aftertreatment improvements for MHD and HHD diesel
  engines are covered via the engineering costs (see text). For LH
  diesel engines, we have included the cost of aftertreatment
  improvements as a technology cost.

    The overall costs for each diesel engine regulatory subcategory are 
included in Table III-19.

         Table III-19--Diesel Engine Technology Costs per Engine
                                 [2009$]
------------------------------------------------------------------------
                                                          2014     2017
------------------------------------------------------------------------
LHD Diesel............................................     $388     $358
MHD Diesel............................................      234      216
HHD Diesel............................................      234      216
------------------------------------------------------------------------

Reasonableness of the Final Standards
    The final engine standards appear to be reasonable and consistent 
with the agencies' respective authorities. With respect to the 2014 and 
2017 MY standards, all of the technologies on which the standards are 
based have already been demonstrated and their effectiveness is well 
documented. The final standards reflect a 100 percent application rate 
for these technologies.

[[Page 57238]]

The costs of adding these technologies remain modest across the various 
engine classes as shown in Table III-19. Use of these technologies 
would add only a small amount to the cost of the vehicle,\292\ and the 
associated reductions are highly cost effective, an estimated $20 per 
ton of CO2eq per vehicle.\293\ This is even more cost 
effective than the estimated cost effectiveness for CO2eq 
removal and fuel economy improvement under the light-duty vehicle rule, 
already considered by the agencies to be a highly cost effective 
reduction.\294\ Accordingly, EPA and NHTSA view these standards as 
reflecting an appropriate balance of the various statutory factors 
under section 202(a) of the CAA and under NHTSA's EISA authority at 49 
U.S.C. 32902(k)(2). Based on the discussion above, NHTSA believes these 
standards are the maximum feasible under EISA.
---------------------------------------------------------------------------

    \292\ Sample 2010 MY vocational vehicles range in price between 
$40,000 for a Class 4 work truck to approximately $200,000 for a 
Class 8 refuse hauler. See pages 16-17 of ICF's ``Investigation of 
Costs for Strategies to Reduce Greenhouse Gas Emissions for Heavy-
Duty On-Road Vehicles.'' July 2010.
    \293\ See RIA chapter 7, Table 7-4.
    \294\ The light-duty rule had a cost per ton of $50 when 
considering the vehicle program costs only and a cost of -$210 per 
ton considering the vehicle program costs along with fuel savings in 
2030. See 75 FR 25515, Table III.H.3-1.
---------------------------------------------------------------------------

(v) Alternative Diesel Engine Standards Considered
    Other than the specific option related to legacy engine products, 
the agencies are not finalizing diesel engine standards less stringent 
than the final standards because the agencies believe these standards 
are highly cost effective.
    The agencies have not considered finalizing diesel engine standards 
which are more stringent because we have exhausted the list of engine 
technologies that we believe are directly applicable to medium- and 
heavy-duty diesel engines used in vocational applications. We are 
continuing to evaluate the potential for bottoming cycle technologies 
to be used in the future, however it is not clear today that this 
technology, although promising for more steady-state operation will 
provide any significant efficiency improvement under the more transient 
operating cycles typical of vocational vehicles. Moreover, as stated at 
II.D above, the agencies do not believe that this technology will be 
available in the time frame of this rule in any case.

IV. Final Regulatory Flexibility Provisions

    This section describes flexibility provisions intended to advance 
the goals of the overall program while providing alternate pathways to 
achieve those goals, consistent with the agencies' statutory authority, 
as well as with Executive Order 13563.\295\ The primary flexibility 
provisions for combination tractors and vocational vehicles and the 
engines installed in these vehicles are incorporated in a program of 
averaging, banking, and trading of credits. For HD pickups and vans, 
the primary flexibility provision is also an ABT program expressed in 
the fleet average form of the standards, along with provisions for 
credit and deficit carry-forward and for trading, patterned after the 
agencies' light-duty vehicle GHG and CAFE programs. Furthermore, EPA 
will allow manufacturers to comply with the N2O and 
CH4 standards using CO2 credits and is providing 
an opportunity for engine manufacturers to earn N2O credits 
that can be used to comply with the CO2 standards. However, 
EPA is not adopting an emission credit program associated with the 
CH4 or HFC standards. This section also describes other 
flexibility provisions that apply, including advanced technology 
credits, innovative technology credits and early compliance credits.
---------------------------------------------------------------------------

    \295\ Section 4 of EO 13563 states that ``Where relevant, 
feasible, and consistent with regulatory objectives, and to the 
extent permitted by law, each agency shall identify and consider 
regulatory approaches that reduce burdens and maintain flexibility 
and freedom of choice for the public.'' 76 FR 3821 (Jan. 21, 2011).
---------------------------------------------------------------------------

A. Averaging, Banking, and Trading Program

    Averaging, Banking, and Trading (ABT) of emissions credits have 
been an important part of many EPA mobile source programs under CAA 
Title II, including engine and vehicle programs. NHTSA has also long 
had an averaging and banking program for light-duty CAFE under EPCA, 
and recently gained authority to add a trading program for light-duty 
CAFE through EISA. ABT programs are useful because they can help to 
address many issues of technological feasibility and lead-time, as well 
as considerations of cost. They provide manufacturers flexibilities 
that assist the efficient development and implementation of new 
technologies and therefore enable new technologies to be implemented at 
a more aggressive pace than without ABT. ABT programs are more than 
just add-on provisions included to help reduce costs, and can be, as in 
EPA's Title II programs an integral part of the standard setting 
itself. A well-designed ABT program can also provide important 
environmental and energy security benefits by increasing the speed at 
which new technologies can be implemented (which means that more 
benefits accrue over time than with slower-starting standards) and at 
the same time increase flexibility for, and reduce costs to, the 
regulated industry. American Council for an Energy-Efficient Economy 
(ACEEE) has commented that ABT and related flexibilities should not be 
offered for this program because the agencies are not promoting the use 
of new technologies but rather the use of existing technologies. 
However, without ABT provisions (and other related flexibilities), 
standards would typically have to be numerically less stringent since 
the numerical standard would have to be adjusted to accommodate issues 
of feasibility and available lead time. See 75 FR at 25412-13. By 
offering ABT credits and additional flexibilities the agencies can 
offer progressively more stringent standards that help meet our fuel 
consumption reduction and GHG emission goals at a faster pace.
    Section II above describes EPA's GHG emission standards and NHTSA's 
fuel consumption standards. For each of these respective sets of 
standards, the agencies also offer ABT provisions, consistent with each 
agency's statutory authority. The agencies worked closely to design 
these provisions to be essentially identical to each other in form and 
function. Because of this fundamental similarity, the remainder of this 
section refers to these provisions collectively as ``the ABT program'' 
except where agency-specific distinctions are required.
    As discussed in detail below, the structure of the GHG and fuel 
consumption ABT program for HD engines was based closely on EPA's 
earlier ABT programs for HD engines; the program for HD pickups and 
vans was built on the existing light-duty GHG program flexibility 
provisions; and the first-time ABT provisions for combination tractors 
and vocational vehicles are as consistent as possible with EPA's other 
HD vehicle regulations. The flexibility provisions associated with this 
new regulatory category were intended to build systematically upon the 
structure of the existing programs.
    As an overview, ``averaging'' means the exchange of emission or 
fuel consumption credits between engine families or truck families 
within a given manufacturer's regulatory subcategories and averaging 
sets. For example, specific ``engine families,'' which manufacturers 
create by dividing their product lines into groups expected to have 
similar emission characteristics throughout their useful life, would be 
contained within an averaging set.

[[Page 57239]]

Averaging allows a manufacturer to certify one or more engine families 
(or vehicle families, as appropriate) within the same averaging set at 
levels worse than the applicable emission or fuel consumption standard. 
The increased emissions or fuel consumption over the standard would 
need to be offset by one or more engine (or vehicle) families within 
that manufacturer's averaging set that are certified better than the 
same emission or fuel consumption standard, such that the average 
emissions or fuel consumption from all the manufacturer's engine 
families, weighted by engine power, regulatory useful life, and 
production volume, are at or below the level of the emission or fuel 
consumption standard \296\ Total credits for each averaging set within 
each model year are determined by summing together the credits 
calculated for every engine family within that specific averaging set.
---------------------------------------------------------------------------

    \296\ The inclusion of engine power, useful life, and production 
volume in the averaging calculations allows the emissions or fuel 
consumption credits or debits to be expressed in total emissions or 
consumption over the useful life of the credit-using or generating 
engine sales.
---------------------------------------------------------------------------

    ``Banking'' means the retention of emission credits by the 
manufacturer for use in future model year averaging or trading. 
``Trading'' means the exchange of emission credits between 
manufacturers, which can then be used for averaging purposes, banked 
for future use, or traded to another manufacturer.
    In EPA's current HD engine program for criteria pollutants, 
manufacturers are restricted to averaging, banking and trading only 
credits generated by the engine families within a regulatory 
subcategory, and EPA and NHTSA proposed to continue this restriction in 
the GHG and fuel consumption program for engines and vehicles. However, 
the agencies sought comment on potential alternative approaches in 
which fewer restrictions are placed on the use of credits for 
averaging, banking, and trading. Particularly, the agencies requested 
comment on removing prohibitions on averaging and trading between some 
or all regulatory categories in the proposal, and on removing 
restrictions between some or all regulatory subcategories that are 
within the same regulatory category (e.g., allowing trading of credits 
between Class 7 day cabs and Class 8 sleeper cabs).
    The agencies received many comments on the restrictions proposed 
for the ABT program, namely on the proposal that credits could only be 
averaged within the specified vehicle and engine subcategories and not 
averaged across subcategories or between vehicle and engine categories. 
Many commenters, including Union of Concerned Scientist (UCS), NY Dept 
of Transportation, Natural Resources Defense Council, Oshkosh, and 
Autocar, requested that the agencies maintain the restrictions as 
proposed in the NPRM. UCS argued that allowing credits to be used 
across categories could undermine further technology advancements, and 
that manufacturers that have broad portfolios would have advantages 
over those manufacturers that do not. The Center for Biological 
Diversity (CBD) argued that because of the various credit opportunities 
in the ABT program and the potential that manufacturers will pay 
penalties rather than comply with the standards, the program could 
actually cause an increase in emissions and a decrease in fuel 
efficiency. On the other hand, several commenters, including EMA/TMA, 
Cummins, Volvo, and ATA, requested that the agencies maintain the 
proposed restrictions of averaging credits between the engine and 
vehicle categories, but reduce the restrictions on credit averaging 
across vehicle subcategories or engine subcategories or averaging sets 
within similar vehicle and engine weight classes (LHD, MHD and HHD). 
Cummins requested that the agencies allow credit averaging between 
engine subcategories within the same weight classes (LHD, MHD and HHD). 
Cummins explained that tractor and vocational engines in the 
corresponding weight classes not only share the same useful life but 
also use the same emission and fuel consumption technologies and 
therefore should be placed into the same engine averaging set. EMA/TMA 
argued that the NPRM restrictions would inhibit a manufacturer's 
ability to use credits to address market fluctuations, which would 
reduce the flexibility that the ABT program was intended to provide. As 
an example, EMA/TMA stated that if the line-haul market were depressed 
for a period of time a manufacturer could make up any deficit selling 
more low-roof tractors with regional hauling operations. The same 
market shift could eliminate a manufacturer's ability to generate 
credits using its aerodynamic high-roof sleeper cab tractors and could 
create a credit deficit if there is a demand for more of the less 
aerodynamic low-roof tractors. EMA/TMA argued that credit exchanges 
across vehicle categories within the same weight classes within the 
tractor subcategories and across vocational vehicle and tractor 
subcategories would allow a manufacturer more flexibility to deal with 
these types of market and customer demand situations. Finally, several 
commenters, including Ford, DTNA NADA, NTEA and Navistar, requested 
that the agencies reduce the proposed restrictions even further by 
allowing credit averaging between vehicle categories and engine 
categories. Navistar argued that more flexibility was necessary for 
manufacturers like itself to increase innovation at a reasonable cost, 
stating that more restrictions would increase costs within a shorter 
time frame.
    After considering these comments, the agencies continue to believe 
that the ABT program developed by the agencies increases and 
accelerates the technological feasibility of the GHG and fuel 
consumption standards by providing manufacturers flexibility in 
implementing new technologies in a way that may be more consistent with 
their business practices and cost considerations. In response to the 
comments submitted by CBD, the agencies disagree with CBD's statements 
that the ABT program will adversely affect the fuel efficiency and GHG 
emission goals of this regulation. This joint final action requires 
vehicle and engine manufacturers to meet increasingly more stringent 
emission and fuel consumption standards which will result in emission 
reductions and fuel consumption savings. Manufacturers will not have 
the option of not meeting the standards. The ABT program simply 
provides each manufacturer the flexibility to meet these standards 
based upon their individual products and implementation plans.
    By assuming the use of credits for compliance, the agencies were 
able to set the fuel consumption/GHG standards at more stringent levels 
than would otherwise have been feasible. One reason is that use of ABT 
allows each manufacturer maximum flexibility to develop compliance 
strategies consistent with its redesign cycles and with its product 
plans generally, allowing the agencies, in turn, to adopt standards 
which are numerically more stringent in earlier model years than would 
be possible with a more rigid program since those rigidities would be 
associated with greater costs. Greater improvements in fuel efficiency 
will occur under more stringent standards; manufacturers will simply 
have greater flexibility to determine where and how to make those 
improvements than they would have without credit options. Further, this 
is consistent with the directive in EO 13563 to ``seek to identify, as 
appropriate, means to

[[Page 57240]]

achieve regulatory goals that are designed to promote innovation.''
    The agencies further agree that certain restrictions on use of ABT 
which were proposed are unnecessary. The proposed ABT program for 
engines was somewhat more restrictive, in its definition of averaging 
sets, than EPA's parallel ABT program for criteria pollutant emissions 
from the same engines. The final rules conform to the ABT provisions 
for GHG heavy-duty engine emissions to be consistent with the parallel 
ABT provisions for criteria pollutants with same weight engines treated 
as a single averaging set regardless of the vehicles in which they are 
installed. We have applied this same principle with respect to 
combination tractors and vocational vehicles: Treating like weight 
classes as an averaging set. The agencies have determined that these 
additional flexibilities will help to reduce manufacturing costs 
further and encourage technology implementation without creating an 
unfair advantage for manufactures with vertically integrated portfolios 
including engines and vehicles. EPA's experience in administering the 
ABT program for heavy-duty diesel engine criteria pollutant emissions 
supports this conclusion. Therefore, the agencies have decided to allow 
credit averaging within and across vocational vehicle and tractor 
subcategories within the same weight class groups, as well as credit 
averaging across the same weight class vocational and tractor engine 
groups. This added flexibility beyond what was proposed in the NPRM 
will not be extended to the HD pickup truck and van category because 
this group of vehicles is comprised of only one subcategory and is not 
broken down like the other categories and corresponding subcategories 
into different weight classes, and the standard applies to the entire 
vehicle, so that there are no separate engine and vehicle standards. 
Put another way, the HD pickup truck and van category is one large 
averaging set that will remain as proposed.
    However, the agencies are maintaining the restrictions against 
averaging vehicle credits with engine credits or between vehicle weight 
classes or engine subcategories for this first phase of regulation. We 
believe averaging or trading credits between averaging sets would be 
problematic because of the diversity of applications involved. This 
diversity creates large differences in the real world conditions that 
impact lifetime emissions--such as actual operating life, load cycles, 
and maintenance practices. In lieu of conducting extensive and 
burdensome real world tracking of these parameters, along with 
corrective measures to provide some assurance of parity between credits 
earned and credits redeemed, averaging sets provide a reasonable amount 
of confidence that typical engines or vehicles within each set have 
comparable enough real world experience to make such follow-up activity 
unnecessary. The agencies believe this approach will ensure that 
CO2 emissions are reduced and fuel consumption is improved 
in each engine subcategory without interfering with the ability of 
manufacturers to engage in free trade and competition. Again, EPA's 
experience in administering its ABT program for criteria pollutant 
emissions from heavy-duty diesel engines confirms these views. The 
agencies also note that no commenter offered an explanation of why the 
restrictions on this ABT program should differ from the parallel ABT 
program respecting criteria pollutants. As explained earlier in this 
preamble, the agencies intend to re-evaluate the appropriateness of the 
ABT averaging sets and credit use restrictions we are adopting here for 
the HD GHG and fuel consumption program in the future based on 
information we gain implementing this first phase of regulation.
    Under previous ABT programs for other rulemakings, EPA and NHTSA 
have allowed manufacturers to carry forward credit deficits for a set 
period of time--if a manufacturer cannot meet an applicable standard in 
a given model year, it may make up its shortfall by overcomplying in a 
subsequent year. In the NPRM the agencies proposed to allow 
manufacturers of engines, tractors, HD pickups and vans, and vocational 
vehicles to carry forward deficits for up to three years before 
reconciling the shortfall--the same period allowed in numerous other 
EPA rules--but sought comments on alternative approaches for 
reconciling deficits. DTNA supported the three year period and stated 
that it was sufficient for reconciling deficits. CBD did not support 
the use of the carry forward of deficits because it would delay 
investments and technological innovation. The agencies respectfully 
disagree with CBD and believe this provision has enabled the agencies 
to consider overall standards that are more stringent and that will 
become effective sooner than we could consider with a more rigid 
program, one in which all of a manufacturer's similar vehicles or 
engines would be required to achieve the same emissions or fuel 
consumption levels, and at the same time. Therefore the agencies 
included in the final rulemaking the proposed 3 year reconciliation 
period. However, the agencies' respective credit programs require 
manufacturers to use credits to offset a shortfall before credits may 
be banked or traded for additional model years. This restriction 
reduces the chance of manufacturers passing forward deficits before 
reconciling shortfalls and exhausting those credits before reconciling 
past deficits.
    For the heavy-duty pickup and van category, the agencies proposed a 
5-year credit life provision, as adopted in the light-duty vehicle GHG/
CAFE program. Navistar requested that the agencies drop the 5-year 
credit expiration date proposed for the heavy-duty pickup and van 
category and not specify an expiration date for earned credits. 
Navistar stated that such credits are necessary to further improve the 
flexibilities of this program in order to meet the new stringent 
standards within the limited lead time provided. The agencies disagree. 
The 5-year credit life is substantial, and allows credits earned early 
in the phase-in to be held and used without discounting throughout the 
phase-in period.
    For engines, vocational vehicles and tractors, EPA also proposed 
that CO2 credits generated during this first phase of the HD 
National Program could not be used for later phases of standards, but 
NHTSA did not expressly specify the potential expiration of fuel 
consumption credits. DTNA and Cummins requested that the surplus 
credits from the first phase of the program not expire. DTNA suggested 
that the agencies drop any reference to credit expiration until the 
next rulemaking, at which time the agencies would have a better 
understanding of actual credit balances and what kind of lifespan for 
credits might be necessary or appropriate. DTNA argued that in some of 
EPA's past programs, EPA had delayed a final decision about credit 
expiration until development of the subsequent rule when, EPA had a 
better understanding of associated credit balances, along with the 
stringency of the standards being proposed for future model years. EPA 
had proposed to limit the lifespan of credits earned to the first phase 
of standards in the interest of ensuring a level playing field before 
the next phase begins. Upon further consideration, the agencies 
recognize that this is a new program and it is unknown whether any 
manufacturers will have credit surpluses by the end of the first phase 
of standards, much less whether some manufacturers will have 
significantly larger credit surpluses that might create an unlevel 
playing field going into the next phase. The agencies

[[Page 57241]]

are adopting a 5-year credit life provision for all regulatory 
categories, as adopted in the light-duty vehicle program and proposed 
for the HD pickup trucks and vans.\297\
---------------------------------------------------------------------------

    \297\ Note, however, that manufacturers have no property right 
in these credits, so no issues of deprivation of property arise if 
later rules choose not to recognize those credits. See 69 FR at 
39001-002 (June 29, 2004).
---------------------------------------------------------------------------

    The following sections provide further discussions of the 
flexibilities provided in this action under the ABT program and the 
agencies' rationale for providing them.
(1) Heavy-duty Engines
    For the heavy-duty engine ABT program, EPA and NHTSA proposed to 
use six averaging sets per 40 CFR 1036.740 for EPA and 49 CFR 535.7(d) 
for NHTSA, which aligned with the proposed regulatory engine 
subcategories. As described above, the agencies have decided that these 
engine averaging sets should be the same as for criteria pollutants 
under the EPA heavy-duty diesel engine rules, and agree with commenters 
that increasing the size of averaging sets from within subcategories to 
across subcategories within the same engine weight class would provide 
important additional flexibilities for engine manufacturers without 
negatively impacting fuel savings or emissions reductions. The agencies 
are therefore adopting four engine averaging sets rather than the 
proposed six. The four engine averaging sets are light heavy-duty (LHD) 
diesel, medium heavy-duty (MHD) diesel, heavy heavy-duty (HHD) diesel, 
and gasoline or spark ignited engines without distinction for the type 
of vehicle in which the engine is installed. Thus, the final ABT 
program will allow for averaging, banking, and trading of credits 
between HHD diesel engines which are certified for use in vocational 
vehicles and HHD diesel engines which are certified for installation in 
tractors. Similarly, the MHD diesel engines certified for use in either 
vocational vehicles or tractors will be treated as a single averaging 
set. As noted in Section I.G above, the agencies intend to monitor this 
program and consider possibilities of more widespread trading based on 
experience in implementing the program as the first engines and 
vehicles certified to the new standards are introduced. Credits 
generated by engine manufacturers under this ABT program are restricted 
for use only within their engine averaging set, based on performance 
against the standard as defined in Section II.B and II.D. Thus, LHD 
diesel engine manufacturers can only use their LHD diesel engine 
credits for averaging, banking and trading with LHD diesel engines, not 
with MHD diesel or HHD diesel engines. As noted, this limitation is 
consistent with ABT provisions in EPA's existing criteria pollutant 
program for engines and will help avoid problems created by the 
diversity of applications that the broad spectrum of HD engines goes 
into, as discussed above.
    The compliance program for the final rules adopts the proposed 
method for generating a manufacturer's CO2 emission and fuel 
consumption credit or deficit. The manufacturer's certification test 
results would serve as the basis for the generation of the 
manufacturer's Family Certification Level (FCL). The agencies did not 
receive comment on this, and continue to believe that it is the best 
approach. The FCL is a new term we proposed for this program to 
differentiate the purpose of this credit generation technique from the 
Family Emission Limit (FEL) previously used in a similar context in 
other EPA rules. A manufacturer may define its FCL at any level at or 
above the certification test results. Credits for the ABT program are 
generated when the FCL is compared to its CO2 and fuel 
consumption stan