[Federal Register Volume 75, Number 229 (Tuesday, November 30, 2010)]
[Proposed Rules]
[Pages 74151-74456]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-28120]



[[Page 74151]]

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Part II





Environmental Protection Agency





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40 CFR Parts 85, 86, 1036, et al.





Department of Transportation





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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; Proposed Rule

Federal Register / Vol. 75 , No. 229 / Tuesday, November 30, 2010 / 
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 85, 86, 1036, 1037, 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-9219-4]
RIN 2060-AP61; RIN 2127-AK74


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

AGENCIES: Environmental Protection Agency (EPA) and National Highway 
Traffic Safety Administration (NHTSA), Department of Transportation 
(DOT).

ACTION: Proposed rules.

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SUMMARY: EPA and NHTSA, on behalf of the Department of Transportation, 
are each proposing rules to establish a comprehensive Heavy-Duty 
National Program that will reduce greenhouse gas emissions and increase 
fuel efficiency 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 proposed fuel 
consumption standards and EPA's proposed carbon dioxide 
(CO2) emissions standards would be tailored to each of three 
regulatory categories of heavy-duty vehicles: Combination Tractors; 
Heavy-Duty Pickup Trucks and Vans; and Vocational Vehicles, as well as 
gasoline and diesel heavy-duty engines. EPA's proposed 
hydrofluorocarbon emissions standards would apply to air conditioning 
systems in tractors, pickup trucks, and vans, and EPA's proposed 
nitrous oxide (N2O) and methane (CH4) emissions 
standards would apply to all heavy-duty engines, pickup trucks, and 
vans. EPA is also requesting comment on possible alternative 
CO2-equivalent approaches for model year 2012-14 light-duty 
vehicles.
    EPA's proposed greenhouse gas emission standards under the Clean 
Air Act would begin with model year 2014. NHTSA's proposed fuel 
consumption standards under the Energy Independence and Security Act of 
2007 would be voluntary in model years 2014 and 2015, becoming 
mandatory with model year 2016 for most regulatory categories. 
Commercial trailers would not be regulated in this phase of the Heavy-
Duty National Program, although there is a discussion of the 
possibility of future action for trailers.

DATES: Comments: Comments on all aspects of this proposal must be 
received on or before January 31, 2011. Under the Paperwork Reduction 
Act, comments on the information collection provisions must be received 
by the Office of Management and Budget on or before December 30, 2010. 
See the SUPPLEMENTARY INFORMATION section on ``Public Participation'' 
for more information about written comments.
    Public Hearings: NHTSA and EPA will jointly hold two public 
hearings on the following dates: November 15, 2010 in Chicago, IL; and 
November 18, 2010 in Cambridge, MA, as announced at 75 FR 67059, 
November 1, 2010. The hearing in Chicago will start at 11 a.m. local 
time and continue until 5 p.m. or until everyone has had a chance to 
speak. The hearing in Cambridge will begin at 10 a.m. and continue 
until 5 p.m. or until everyone has had a chance to speak. See ``How Do 
I Participate in the Public Hearings?'' below at B. (7) under the 
SUPPLEMENTARY INFORMATION section on ``Public Participation'' for more 
information about the public hearings.

ADDRESSES: Submit your comments, identified by Docket ID No. NHTSA-
2010-0079 and/or EPA-HQ-OAR-2010-0162, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: a-and-r-docket@epa.gov.
     Fax: NHTSA: (202) 493-2251; EPA: (202) 566-9744.
     Mail:
    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.
    EPA: Air Docket, Environmental Protection Agency, EPA Docket 
Center, Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 
20460. In addition, please mail a copy of your comments on the 
information collection provisions to the Office of Information and 
Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk 
Officer for EPA, 725 17th St., NW., Washington, DC 20503.
     Hand Delivery:
    NHTSA: West Building, Ground Floor, Rm. W12-140, 1200 New Jersey 
Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m. Eastern 
Time, Monday through Friday, except Federal Holidays.
    EPA: EPA Docket Center, (Air Docket), U.S. Environmental Protection 
Agency, EPA West Building, 1301 Constitution Ave., NW., Room: 3334, 
Mail Code 2822T, Washington, DC. Such deliveries are only accepted 
during the Docket's normal hours of operation, and special arrangements 
should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. NHTSA-2010-0079 
and/or EPA-HQ-OAR-2010-0162. See the SUPPLEMENTARY INFORMATION section 
on ``Public Participation'' for additional instructions on submitting 
written comments.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. 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, will be 
publicly available only in hard copy in EPA's docket, but may be 
available electronically in NHTSA's docket at regulations.gov. Publicly 
available docket materials are available either electronically in 
http://www.regulations.gov or in hard copy at the following locations:
    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.
    EPA: EPA Docket Center, EPA/DC, EPA West, Room 3334, 1301 
Constitution Ave., NW., 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 Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: NHTSA: Rebecca Yoon, 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 Assessment and Standards Division Hotline; 
telephone number; (734) 214-4636; e-mail asdinfo@epa.gov.

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SUPPLEMENTARY INFORMATION:

Does this action apply to me?

    This action would affect 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.\1\ 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 
standards and corporate average fuel economy standards issued for 
light-duty model year 2012-2016 vehicles. This action also includes a 
discussion of the possible future regulation of commercial trailers and 
is requesting comment on possible alternative CO2-equivalent 
approaches for model year 2012-14 light-duty vehicles. Potentially 
affected categories and entities include the following:
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    \1\ For purposes of NHTSA's fuel consumption regulations, non-
commercial recreational vehicles will not be covered, even if they 
would otherwise fall under these categories. See 49 U.S.C. 
32901(a)(7).
[GRAPHIC] [TIFF OMITTED] TP30NO10.000

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
proposal. This table lists the types of entities that the agencies are 
now aware could potentially be regulated by this action. Other types of 
entities not listed in the table could also be regulated. To determine 
whether your activities may be regulated by this action, you should 
carefully examine the applicability criteria in 40 CFR parts 1036 and 
1037, 49 CFR parts 523, 534, and 535, and 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.

B. Public Participation

    NHTSA and EPA request comment on all aspects of these joint 
proposed rules. This section describes how you can participate in this 
process.

(1) How do I prepare and submit comments?

    In this joint proposal, there are many aspects of the program 
common to both EPA and NHTSA. For the convenience of all parties, 
comments submitted to the EPA docket (whether hard copy or electronic) 
will be considered comments submitted to the NHTSA docket, and vice 
versa. An exception is that comments submitted to the NHTSA docket on 
the Draft Environmental Impact Statement will not be considered 
submitted to the EPA docket. Therefore, the public only needs to submit 
comments to either one of the two agency dockets. Comments that are 
submitted for consideration by one agency should be identified as such, 
and comments that are submitted for consideration by both agencies 
should be identified as such. Absent such identification, each agency 
will exercise its best judgment to determine whether a comment is 
submitted on its proposal.
    Further instructions for submitting comments to either the EPA or 
NHTSA docket are described below.

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    NHTSA: Your comments must be written and in English. To ensure that 
your comments are correctly filed in the Docket, please include the 
Docket I.D No. NHTSA-2010-0079 in your comments. By regulation, your 
comments must not be more than 15 pages long (49 CFR 553.21). NHTSA 
established this limit to encourage you to write your primary comments 
in a concise fashion. However, you may attach necessary additional 
documents to your comments. There is no limit on the lenght of the 
attachments. If you are submitting comments electronically as a PDF 
(Adobe) file, we ask that the documents submitted be scanned using the 
Optical Character Recognition (OCR) process, thus allowing the agencies 
to search and copy certain portions of your submissions.\2\ Please note 
that pursuant to the Data Quality Act, in order for the substantive 
data to be relied upon and used by the agencies, it must meet the 
information quality standards set forth in the OMB and Department of 
Transportation (DOT) Data Quality Act quidelines. Accordingly, we 
encourage you to consult the guidelines in preparing your comments. 
OMB's guidelines may be accessed at http://www.whitehouse.gov/omb/fedreg/reproducible.html. DOT's guidelines may be access at http://regs.dot.gov.
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    \2\ Optical character recognition (OCR) is the process of 
converting an image of text, such as a scanned paper document or 
electronic fax file, into computer-editable text.
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    EPA: Direct your comments to Docket ID No EPA-HQ-OAR-2010-0162. 
EPA's policy is that all comments received will be included in the 
public docket without change and may be made available online at http://www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through http://www.regulations.gov or e-
mail. The http://www.regulations.gov Web site is an ``anonymous 
access'' system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through http://www.regulations.gov your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket visit the 
EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.

(2) Tips for Preparing Your Comments

    When submitting comments, remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agencies may ask you to respond to 
specific questions or organize comments by referencing a part or 
section number from the Code of Federal Regulations.
     Explain why you agree or disagree, suggest alternatives, 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified in the DATES section above.

(3) How can I be sure that my comments were received?

    NHTSA: If you submit your comments by mail and wish Docket 
Management to notify you upon its receipt of your comments, enclose a 
self-addressed, stamped postcard in the envelope containing your 
comments. Upon receiving your comments, Docket Management will return 
the postcard by mail.

(4) How do I submit confidential business information?

    Any CBI submitted to one of the agencies will also be available to 
the other agency.\3\ However, as with all public comments, any CBI 
information only needs to be submitted to either one of the agencies' 
dockets and it will be available to the other. Following are specific 
instructions for submitting CBI to either agency.
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    \3\ This statement constitutes notice to commenters pursuant to 
40 CFR 2.209(c) that EPA will share confidential business 
information received with NHTSA unless commenters expressly specify 
that they wish to submit their CBI only to EPA and not to both 
agencies.
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    NHTSA: If you wish to submit any information under a claim of 
confidentiality, you should submit three copies of your complete 
submission, including the information you claim to be CBI, to the Chief 
Counsel, NHTSA, at the address given above under FOR FURTHER 
INFORMATION CONTACT. When you send a comment containing CBI, you should 
include a cover letter setting forth the information specified in our 
CBI regulation. In addition, you should submit a copy from which you 
have deleted the claimed CBI to the Docket by one of the methods set 
forth above.
    EPA: Do not submit CBI to EPA through http://www.regulations.gov or 
e-mail. Clearly mark the part or all of the information that you claim 
to be CBI. For CBI in a disk or CD-ROM that you mail to EPA, mark the 
outside of the disk or CD-ROM as CBI and then identify electronically 
within the disk or CD-ROM the specific information that is claimed as 
CBI. In addition to one complete version of the comment that includes 
information claimed as CBI, a copy of the comment that does not contain 
the information claimed as CBI must be submitted for inclusion in the 
public docket. Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.

(5) Will the agencies consider late comments?

    NHTSA and EPA will consider all comments received before the close 
of business on the comment closing date indicated above under DATES. To 
the extent practicable, we will also consider comments received after 
that date. If interested persons believe that any new information the 
agency places in the docket affects their comments, they may submit 
comments after the closing date concerning how the agency should 
consider that information for the final rules. However, the agencies' 
ability to consider any such late comments in this rulemaking will be 
limited due to the time frame for issuing the final rules.
    If a comment is received too late for us to practicably consider in 
developing the final rules, we will consider that comment as an 
informal suggestion for future rulemaking action.

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How can I read the comments submitted by other people?

    You may read the materials placed in the dockets for this document 
(e.g., the comments submitted in response to this document by other 
interested persons) at any time by going to http://www.regulations.gov. 
Follow the online instructions for accessing the dockets. You may also 
read the materials at the NHTSA Docket Management Facility or the EPA 
Docket Center by going to the street addresses given above under 
ADDRESSES.

How do I participate in the public hearings?

    EPA and NHTSA will jointly host two public hearings. The November 
15 hearing will be held at the Millennium Knickerbocker Hotel Chicago, 
163 East Walton Place (at N. Michigan Ave.), Chicago, Illinois 60611. 
The November 18, 2010 hearing will be held at the Hyatt Regency 
Cambridge, 575 Memorial Drive, Cambridge, Massachusetts 02139-4896. If 
you would like to present oral testimony at a public hearing, we ask 
that you notify both the NHTSA and EPA contact persons listed under FOR 
FURTHER INFORMATION CONTACT at least ten days before the hearing. Once 
the agencies learn how many people have registered to speak at the 
public hearings, we will allocate an appropriate amount of time to each 
participant, allowing time for necessary breaks. For planning purposes, 
each speaker should anticipate speaking for approximately ten minutes, 
although we may need to shorten that time if there is a large turnout. 
We request that you bring three copies of your statement or other 
material for the agencies' panels. To accommodate as many speakers as 
possible, we prefer that speakers not use technological aids (e.g., 
audio-visuals, computer slideshows). In addition, we will reserve a 
block of time for anyone else in the audience who wants to give 
testimony.
    Each hearing will be held at a site accessible to individuals with 
disabilities. Individuals who require accommodations such as sign 
language interpreters should contact the persons listed under FOR 
FURTHER INFORMATION CONTACT section above no later than ten days before 
the date of the hearing.
    EPA and NHTSA will conduct the hearings informally, and technical 
rules of evidence will not apply. We will arrange for a written 
transcript of each hearing and keep the official records of the 
hearings open for 30 days to allow you to submit supplementary 
information. You may make arrangements for copies of a transcript 
directly with the court reporter.

C. Additional Information About This Rulemaking

    EPA's Advance Notice of Proposed Rulemaking for regulating 
greenhouse gases under the CAA (see 73 FR 44353, July 30, 2008) 
included a discussion of possible rulemaking paths for the heavy-duty 
transportation sector. This notice of proposed rulemaking relies in 
part on information that was obtained from that notice, which can be 
found in Public Docket EPA-HQ-OAR-2008-0318. That docket is 
incorporated into the docket for this action, EPA-HQ-OAR-2010-0162.

Table of Contents

A. Does this action apply to me?
B. Public Participation
C. Additional Information About This Rulemaking
I. Overview
    A. Introduction
    B. Building Blocks of the Heavy-Duty National Program
    C. Summary of the Proposed 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. Proposed GHG and Fuel Consumption Standards for Heavy-Duty 
Engines and Vehicles
    A. What vehicles would 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 Provisions
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. Proposed Regulatory Flexibility Provisions
    A. Averaging, Banking, and Trading Program
    B. Additional Proposed Flexibility Provisions
V. NHTSA and EPA Proposed 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 would this proposed 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 
Proposal's GHG Emissions Reductions
VII. How would this proposal 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 proposed program?
    A. Conceptual Framework for Evaluating Impacts
    B. Costs Associated With the Proposed 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. Summary of Costs and Benefits From the Greenhouse Gas 
Emissions Perspective
    L. Summary of Costs and Benefits From the Fuel Efficiency 
Perspective
IX. Analysis of Alternatives
    A. What are the alternatives that the agencies considered?
    B. How do these alternatives compare in overall GHG emissions 
reductions, fuel efficiency and cost?
    C. How would the agencies include commercial trailers, as 
described in alternative 7?
X. Recommendations From the 2010 NAS Report
    A. Overview
    B. What were the major findings and recommendations of the 2010 
NAS report, and how is the proposed HD national program consistent 
with them?
XI. Statutory and Executive Order Reviews
XII. 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 improve fuel 
efficiency 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, after light-duty passenger cars and trucks.
    In a recent memorandum to the Administrators of EPA and NHTSA (and 
the Secretaries of Transportation and

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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.'' \4\ Earlier this year, 
EPA and NHTSA established for the first time a national program to 
sharply reduce GHG emissions and fuel consumption from passenger cars 
and light trucks. Now, each agency is proposing rules that together 
would create a strong and comprehensive Heavy-Duty National Program 
(``HD National Program'') designed to address the urgent and closely 
intertwined challenges of dependence on oil, energy security, and 
global climate change. At the same time, the proposed program would 
enhance American competitiveness and job creation, benefit consumers 
and businesses by reducing costs for transporting goods, and spur 
growth in the clean energy sector.
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    \4\ 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.
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    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 a HD 
National Program based on a common set of principles. In the letters, 
the stakeholders commit 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 proposed HD National Program builds on many years of heavy-duty 
engine and vehicle technology development to achieve what the agencies 
believe would be the greatest degree of GHG emission and fuel 
consumption reduction appropriate, feasible, and cost-effective for the 
model years in question. Still, by proposing to take 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 GHG 
emissions and fuel consumption. For example, NHTSA and EPA have stopped 
short of proposing fuel consumption and GHG emissions standards for 
trucks based on use of hybrid powertrain technology. Similarly, we 
expect that 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 such opportunities emerge in 
the coming years, we expect that we will propose a second phase of 
provisions in the future to reinforce these developments and maximize 
the achieved reductions in GHG emissions and fuel consumption reduction 
for the mid- and longer-term time frame.
    In the May 21 memorandum, the President 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 vehicles beginning with the 2014 model year (MY), with the aim of 
issuing a final rule by July 30, 2011.'' This proposed rulemaking is 
consistent with this Presidential Memorandum, with each agency 
proposing rules under its respective authority that together comprise a 
coordinated and comprehensive HD National 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. Heavy-duty trucks \5\ have 
always 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.
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    \5\ 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.''
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    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.\6\ It also does not 
include motorcycles. Thus, in this notice, 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.\7\ 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.'' \8\ NHTSA 
interprets this to include all segments of the heavy-duty category 
described above, except for recreational vehicles, such as motor homes, 
since recreational vehicles are not commercial.
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    \6\ Light-Duty Vehicle Greenhouse Gas Emission Standards and 
Corporate Average Fuel Economy Standards; Final Rule 75 FR 
25323,(May 7, 2010).
    \7\ The CAA defines heavy-duty as a truck, bus or other motor 
vehicle 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.
    \8\ 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).
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    Setting GHG emissions standards for the heavy-duty sector will help 
to address climate change, which is widely viewed as a significant 
long-term threat to the global environment. 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

[[Page 74157]]

observed global warming over the last 50 years.\9\ The 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.\10\ Mobile sources addressed in the 
recent 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.\11\ Heavy-duty vehicles emit CO2, CH4, 
N2O, and HFCs and are responsible for nearly 19 percent of 
all mobile source GHGs (nearly 6% 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).\12\
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    \9\ 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.
    \10\ 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 .
    \11\ See Endangerment TSD, Note 9, above, at pp. 180-194.
    \12\ U.S. Environmental Protection Agency. 2009. Inventory of 
U.S. Greenhouse Gas Emissions and Sinks: See Note 10, above.
---------------------------------------------------------------------------

    Setting fuel consumption standards for the heavy-duty sector, 
pursuant to NHTSA's EISA authority, will also improve our energy 
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 60 percent of U.S. 
petroleum consumption. World crude oil production is highly 
concentrated, exacerbating the risks of supply disruptions and price 
shocks. Tight global oil markets led to prices over $100 per barrel in 
2008, with gasoline reaching as high as $4 per gallon in many parts of 
the United States, causing financial hardship for many families and 
businesses. The export of U.S. assets 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.\13\
---------------------------------------------------------------------------

    \13\ In 2009 Source: EIA Annual Energy Outlook 2010 released May 
11, 2010.
---------------------------------------------------------------------------

    In developing this joint proposal, 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\ While our discussions covered a 
wide range of issues and viewpoints, one widespread recommendation was 
that the two agencies should develop a common Federal program with 
consistent standards of performance regarding fuel consumption and GHG 
emissions. The HD National Program we are proposing in this notice is 
consistent with that goal. Further it is our expectation based on our 
ongoing work with the State of California that the California ARB will 
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 are committed to continuing to 
work with California ARB throughout this rulemaking process to help 
ensure our final rules can lead to that outcome.
---------------------------------------------------------------------------

    \14\ Pursuant to DOT Order 2100.2, NHTSA will place a memorandum 
recording those meetings that it attended and documents submitted by 
stakeholders which formed a basis for this proposal 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 proposing 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 proposed fuel 
consumption standards and EPA's proposed GHG standards would apply to 
manufacturers of the following types of heavy-duty vehicles and their 
engines; the proposed 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 recent light-duty vehicle rule establishing CAFE and GHG 
standards for MYs 2012-2016 light-duty vehicles, EPA's and NHTSA's 
proposed 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 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 
emitted 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 
proposing under our separate legal authorities.
---------------------------------------------------------------------------

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

    The timelines for the implementation of the proposed NHTSA and EPA 
standards are also closely coordinated. EPA's proposed GHG emission 
standards would 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 I.B.(5) below, NHTSA's proposed fuel consumption 
standards would be voluntary in model years 2014 and 2015, becoming 
mandatory in model year 2016, except for diesel engine standards which 
would be voluntary in model years 2014, 2015 and 2016, becoming 
mandatory in model year 2017. Both agencies are also allowing early 
compliance in model year 2013. A detailed discussion of how the 
proposed standards are consistent with each agency's respective 
statutory requirements and authorities is found later in this notice.
    Neither EPA nor NHTSA is proposing 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. 
However, the agencies are considering proposing such standards in a 
future rulemaking, and request comment on such an action later in this 
preamble.

B. Building Blocks of the Heavy-Duty National Program

    The standards that are being proposed in this notice represent the 
first time

[[Page 74158]]

that NHTSA and EPA would regulate the heavy-duty sector for fuel 
consumption and GHG emissions, respectively. The proposed 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% less NOX and 99% 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 are projected to provide 
greater than $70 billion in health and welfare benefits annually in 
2030 alone (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 highways. 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 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 proposed program incorporates the 
existing engine-based approach used for criteria emissions 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 economy of commercial medium-
duty and heavy-duty on-highway vehicles and work trucks in three steps: 
A study by NAS, a study by NHTSA, and a rulemaking to develop the 
regulations themselves.\16\
---------------------------------------------------------------------------

    \16\ The NAS study is described below, and the NHTSA study 
accompanies this NPRM.
---------------------------------------------------------------------------

    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; \17\ and
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    \17\ 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 proposing 
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) \18\ that have long governed NHTSA's 
setting of fuel economy standards for passenger cars and light trucks, 
although many of the same factors are considered under each of these 
provisions.
---------------------------------------------------------------------------

    \18\ 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
    As mandated by Congress in EISA, the National Research Council 
(NRC) under NAS recently 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.'' \19\ This study 
covers the same universe of heavy-duty vehicles that is the focus of 
this proposed 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. NHTSA's and EPA's detailed assessments of each of the 
relevant recommendations of the NAS

[[Page 74159]]

report are discussed in Section X of this preamble and in the NHTSA HD 
study accompanying this notice of proposed rulemaking (NPRM).
---------------------------------------------------------------------------

    \19\ 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 Web site 
at http://www.nap.edu/catalog.php?record--id=12845 (last accessed 
September 10, 2010).
---------------------------------------------------------------------------

(4) The Recent NHTSA and EPA Light-Duty National GHG Program
    On April 1, 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. The agencies have 
used the light-duty National Program as a model for this proposed 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 proposed standards and 
compliance structures, although in this proposal each agency proposes 
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 to meet a closely coordinated Federal 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 draft 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 proposed 
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 proposed standards. These 
include such approaches as improved logistics and driver training, as 
discussed in the draft 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, liberalizing 
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 proposed standards and also provide 
benefits for the existing truck fleet, furthering the public policy 
objectives of addressing energy security and climate change.
(6.) Canada's Department of the Environment
    The Government of Canada's Department of the Environment 
(Environment Canada) assisted EPA's development of this proposed 
rulemaking, by conducting emissions testing of heavy-duty vehicles at 
Environment Canada test facilities to gather data on a range of 
possible test cycles.
    We expect the technical collaboration with Environment Canada to 
continue as we address issues raised by stakeholders in response to 
this NPRM, and as we continue to develop details of certain testing and 
compliance verification procedures. We may also be able to 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.

C. Summary of the Proposed 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).\20\ This 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.
---------------------------------------------------------------------------

    \20\ 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 proposed regulations refer 
simply to g/hp-hr. This is consistent with our 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

[[Page 74160]]

inherent efficiency of the engine as well as making changes to the 
vehicles to reduce the amount of work that the engine needs to do per 
mile traveled. This thus requires a focus on the entire vehicle. 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. The 2010 NAS Report recognized this need and 
recommended a complete-vehicle approach to regulation. As described 
elsewhere in this preamble, the proposed standards that make up the HD 
National Program aim to address the complete vehicle, to the extent 
practicable and appropriate under the agencies' respective statutory 
authorities, through complementary engine and vehicle standards, in 
order to reduce the complexity of the regulatory system and achieve the 
greatest gains as soon as possible.
(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.\21\ Table I-1 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.
---------------------------------------------------------------------------

    \21\ 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.001

    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.\22\ 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. Commercial ``vocational'' 
vehicles, which may span Classes 2b through 8, vary widely in size, 
including smaller and larger van trucks, utility ``bucket'' trucks, 
tank 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.
---------------------------------------------------------------------------

    \22\ 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 proposed standards in 
careful consideration of the diversity and complexity of the heavy-duty 
truck industry, as discussed next.
(2) Summary of Proposed 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 proposing to divide 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 proposing related but distinct program 
approaches reflecting the specific challenges that we see for 
manufacturers in these segments. In the following paragraphs, we 
discuss EPA's proposed GHG emission standards and NHTSA's proposed fuel 
consumption standards for the three regulatory categories of heavy-duty 
vehicles and their engines.
    The agencies are proposing 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 alternatively consider fuel consumption as 
the basis for its standards. As a result, for heavy-duty

[[Page 74161]]

pickup trucks and vans, EPA and NHTSA are proposing standards on a per-
mile basis (g/mile for the EPA standards, gallons/100 miles for the 
NHTSA standards), as explained in Section I.C.(2)(b) below. For heavy-
duty trucks, both combination and vocational, the agencies are 
proposing standards expressed in terms of the key measure of freight 
movement, tons of payload miles or, more simply, ton-miles. Hence, for 
EPA the proposed 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 proposed 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 proposing 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 proposing 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 proposed 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.\23\ 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 
would involve improvements such as aerodynamics and tires and reduction 
in idle operation, as well as engine-based efficiency improvements.
---------------------------------------------------------------------------

    \23\ The vast majority of combination tractor-trailers are used 
in highway applications, and these vehicles are the focus of this 
proposed program. A small fraction of combination tractors are used 
in off-road applications and are treated 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 separate from each other. 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 proposing 
standards for the tractors and their engines in this rulemaking, but 
are not proposing standards for trailers in this rulemaking. The 
agencies are requesting comment on potential standards for trailers, 
but will address standards for trailers in a separate rulemaking.
    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 proposing 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, 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 proposed standards to result in the application of 
improved technologies for lower GHG emissions and fuel consumption for 
both the cab and the engine.

[[Page 74162]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.002

    Accordingly, for Class 7 and 8 combination tractors, the agencies 
are each proposing two sets of standards. For vehicle-related emissions 
and fuel consumption, the agencies are proposing that tractor 
manufacturers meet respective vehicle-based standards. Compliance with 
the vehicle standard would 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 proposal. 
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 would also assume the use of a representative typical engine, 
rather than a vehicle-specific engine, because engines are regulated 
separately and include an averaging, banking, and trading program 
separate from the vehicle program. The model and appropriate inputs 
would 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 and the 
evaluation of the model's accuracy, are discussed in detail in Section 
II below and in Chapter 4 of the draft RIA.
---------------------------------------------------------------------------

    \24\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.
---------------------------------------------------------------------------

    EPA and NHTSA also considered developing respective alternative 
standards based on the direct testing of the emissions and fuel 
consumption of the entire vehicle for this category of vehicles, as 
measured using a chassis test procedure. This would be similar to the 
proposed approach for standards for HD pickups and vans discussed 
below. The agencies believe that such an approach warrants continued 
consideration. However, the agencies are not prepared to propose 
chassis-test-based standards at this time, primarily because of the 
very small number of chassis-test facilities that currently exist, but 
rather are proposing only the tractor standards and the engine-based 
standards discussed above. The agencies seek comment on the potential 
benefits and trade-offs of chassis-test-based standards for combination 
tractors.
(1) Proposed Standards for Class 7 and 8 Combination Tractors
    The vehicle standards that EPA and NHTSA are proposing 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 among 
these vehicles. The proposed 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.
    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. Table I-2 presents the 
agencies' respective proposed standards for combination tractor 
manufacturers for the 2017 model year for illustration.
BILLING CODE 6560-50-P

[[Page 74163]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.003

    In addition, the agencies are proposing separate performance 
standards for the engines manufactured for use in these trucks. EPA's 
proposed engine-based CO2 standards and NHTSA's proposed 
engine-based fuel consumption standards would vary based on the 
expected weight class and usage of the truck into which the engine 
would be installed. EPA is also proposing engine-based N2O 
and CH4 standards for manufacturers of the engines used in 
combination tractors. EPA is proposing separate engine-based standards 
for these GHGs because the agency 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. However, NHTSA is not incorporating standards related to 
these GHGs due to their lack of influence on fuel consumption. EPA 
expects that manufacturers of current engine technologies would be able 
to comply with the proposed ``cap'' standards with little or no 
technological improvements; the value of the standards would be to 
prevent significant increases in these emissions as alternative 
technologies are developed and introduced in the future. Compliance 
with the proposed EPA engine-based CO2 standards and the 
proposed NHTSA fuel consumption standards, as well as the proposed EPA 
N2O and CH4 standards, would be determined using 
the appropriate EPA engine test procedure, as discussed in Section II 
below.
    As with the other categories of heavy-duty vehicles, EPA and NHTSA 
are proposing respective standards that would apply to Class 7 and 8 
trucks at the time of production (as in Table I-2, above). In addition, 
EPA is proposing separate standards that would apply for a specified 
period of time in use. All of the proposed standards for these trucks, 
as well as details about the proposed provisions for certification and 
implementation of these standards, are discussed in more detail in 
Sections II, III, IV, and V below and in the draft RIA.
(ii) EPA Proposed Air Conditioning Leakage Standard for Class 7 and 8 
Combination Tractors
    In addition to the proposed EPA tractor- and engine-based standards 
for CO2 and engine-based standards for N2O, and 
CH4 emissions, EPA is also proposing a separate standard to 
reduce leakage of HFC refrigerant from cabin air conditioning systems 
from combination tractors, to apply to the tractor manufacturer. This 
standard would be independent of the CO2 tractor standard, 
as discussed below. Because the current refrigerant used widely in all 
these systems has a very high global warming potential, EPA is 
concerned about leakage of refrigerant over time.\25\
---------------------------------------------------------------------------

    \25\ The global warming potential for HFC-134a refrigerant of 
1430 used in this proposal is consistent with the Intergovernmental 
Panel on Climate Change Fourth Assessment Report.
---------------------------------------------------------------------------

    Because the interior volume to be cooled for most of these truck 
cabins is similar to that of light-duty trucks, the size and design of 
current truck A/C systems is also very similar. The proposed compliance 
approach for Class 7 and 8 tractors is therefore similar to that in the 
light-duty rule in that these proposed standards are design-based. 
Manufacturers would 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 proposed 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 
generate credits towards the CO2 g/mi standard, and EPA took 
into account the expected use of such credits in establishing the 
CO2 emissions standards. In this rule, EPA is proposing that 
manufacturers actually meet a standard--as opposed to having the 
opportunity to earn a credit--for A/C refrigerant leakage. Thus, for 
this rule, refrigerant leakage is not accounted for in the development 
of the proposed 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 the expression of the leakage 
rate. The light-duty A/C leakage standard is expressed in terms of 
grams per year. For this heavy-duty rule, however, because of the wide 
variety of system designs and arrangements, a one-size-fits-all gram 
per year standard would likely be much less relevant, so EPA believes 
it is more appropriate to propose a standard in terms of percent of 
total refrigerant leakage per year. This requires the total refrigerant 
capacity of

[[Page 74164]]

the A/C system to be taken into account in determining compliance. EPA 
believes that this proposed approach--a standard instead of a credit, 
and basing the standard on percent 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 would be determined through a 
showing by the tractor manufacturer that its A/C system incorporated a 
combination of low-leak technologies sufficient to meet the percent 
leakage of the standard. This proposed ``menu'' of technologies is very 
similar to that established in the light-duty GHG rule.\25\
---------------------------------------------------------------------------

    \25\ At this time, EPA is considering approval of an alternative 
refrigerant, HFO-1234yf, which has a very low GWP. The proposed A/C 
leakage standard is designed to account for use of an alternative, 
low-GWP refrigerant. If in the future this refrigerant is approved 
and if it becomes widespread as a substitute for HFC-134a in mobile 
A/C systems, EPA may propose to revise or eliminate the leakage 
standard.
---------------------------------------------------------------------------

    Finally, EPA is not proposing 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. We request comment 
on this decision and whether EPA should reflect A/C system efficiency 
in the final program either as a credit or a stand-alone standard based 
on the same technologies and performance levels as the light-duty 
program.
    A more detailed discussion of A/C related issues is found in 
Section II 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 program, and the agencies are not considering 
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 this proposal as ``HD pickups and vans'') together emit about 20 
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 
pick-up 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 propose 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 propose corresponding gallons per 100 
mile fuel consumption standards that are likewise based on the whole 
vehicle. This complete vehicle approach being proposed 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 proposing, as detailed in Section II.C. These proposed 
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 would 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).\27\
---------------------------------------------------------------------------

    \27\ 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).\28\ 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 weight-based metric provides a better 
attribute than the footprint attribute utilized in the light-duty 
vehicle rulemaking. Weight-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 pick-up or van. EPA and NHTSA 
are therefore proposing standards for HD pickups and vans based on a 
``work factor'' that combines their payload and towing capabilities, 
with an added adjustment for 4-wheel drive vehicles.
---------------------------------------------------------------------------

    \28\ EISA requires CAFE standards for passenger cars and light 
trucks to be attribute-based; see 49 U.S.C. 32902(b)(3)(A).
---------------------------------------------------------------------------

    The agencies are proposing that each manufacturer's fleet average 
standard would be based on production volume-weighting of target 
standards for each vehicle that in turn are based on the vehicle's work 
factor. These target standards would be taken from a set of curves 
(mathematical functions), presented in Section II.C. EPA is also 
proposing that the CO2 standards be phased in gradually 
starting in the 2014 model year, at 15-20-40-60-100 percent in model 
years 2014-2015-2016-2017-2018, respectively. The phase-in would take 
the form of a set of target standard curves, with increasing stringency 
in each model year, as detailed in Section II.C. The EPA standards 
proposed 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. Section II.C also discusses the rationale 
behind the proposal of separate targets for diesel and gasoline vehicle 
standards. EPA is also proposing a manufacturer's alternative 
implementation schedule for

[[Page 74165]]

model years 2016-2018 that parallels and is equivalent to NHTSA's first 
alternative described below.
    NHTSA is proposing to allow manufacturers to select one of two fuel 
consumption standards alternatives for model years 2016 and later. To 
meet the EISA statutory requirement for three year regulatory 
stability, the first alternative would define individual gasoline 
vehicle and diesel vehicle fuel consumption target curves that would 
not change for model years 2016 and later. The proposed target curves 
for this alternative are presented in Section II.C. The second 
alternative would use target curves that are equivalent to the EPA 
program in each model year 2016 to 2018. 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 proposing, to rely on the same product plans to satisfy either 
of these two alternatives, and also EPA requirements. NHTSA is also 
proposing that manufacturers may 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 proposed EPA and NHTSA standard 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 would 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
 Gasoline engine coupled cam phasing
 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 device or container attached. We are proposing that these 
vehicles generally be regulated as Class 2b through 8 vocational 
vehicles, as described in Section I.C(2)(c), because, like other 
vocational vehicles, we have little information on baseline aerodynamic 
performance and expectations for improvement. However, 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 
proposing that these vehicles be included in the chassis-based HD 
pickup and van program. These proposed provisions are described in 
Section V.B.
    In addition to proposed EPA CO2 emission standards and 
the proposed NHTSA fuel consumption standards for HD pickups and vans, 
EPA is also proposing 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 proposing standards that would apply to HD 
pickups and vans in use. All of the proposed standards for these HD 
pickups and vans, as well as details about the proposed 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,\29\ tow 
trucks, among others. These vehicles and their engines contribute 
approximately 15 percent of today's heavy-duty truck sector GHG 
emissions.
---------------------------------------------------------------------------

    \29\ Again, we note that NHTSA's proposed fuel consumption 
standards would not apply to non-commercial vehicles like motor 
homes.
---------------------------------------------------------------------------

    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 are proposing that in this vocational vehicle 
category the chassis manufacturers be the focus of the proposed GHG and 
fuel consumption standards. They play a central role in the 
manufacturing process, and the product they produce--the chassis with 
engine and transmissions--includes the primary technologies that affect 
emissions and fuel consumption. They also constitute a much more 
limited group of manufacturers for purposes of developing a regulatory 
program. In contrast, a focus on the body manufacturers would be much 
less practical, since they represent a much more diverse set of 
manufacturers, and the part of the vehicle that they add has a very 
limited impact on opportunities to reduce GHG emissions and fuel 
consumption (given the limited role that aerodynamics plays in the 
types of lower speed operation typically found with vocational 
vehicles). Therefore, the proposed 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 request comment on our proposed focus on chassis 
manufacturers.
    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 proposing two sets of standards for 
Class 2b-8 vocational vehicles. For vehicle-related emissions and fuel 
consumption, the agencies are proposing standards for chassis 
manufacturers: EPA CO2 (g/ton-mile) standards and NHTSA fuel 
consumption (gal/1,000 ton-mile) standards). Also as in the case of 
Class 7 and 8 tractors, we propose to use GEM, a customized vehicle 
simulation model, to determine compliance with the vocational vehicle 
standards. The primary manufacturer-generated input

[[Page 74166]]

into the proposed compliance model for this category of trucks would 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. The model would also assume the use of a 
typical representative engine in the simulation, resulting in an 
overall value for CO2 emissions and one for fuel 
consumption. As is the case for combination tractors, the manufacturers 
of the engines intended for vocational vehicles would be subject to 
separate engine-based standards.
(i) Proposed Standards for Class 2b-8 Vocational Vehicles
    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, as proposed for 
combination tractors, EPA and NHTSA are proposing separate standards 
for the manufacturers of engines used in Class 2b-8 vocational 
vehicles. EPA's proposed engine-based CO2 standards and 
NHTSA's proposed engine-based fuel consumption standards would vary 
based on the expected weight class and usage of the truck into which 
the engine would be installed. The agencies propose to use the 
groupings EPA currently uses for other heavy-duty engine standards--
light heavy-duty, medium heavy-duty, and heavy heavy-duty, as discussed 
in Section II below.
    Tire rolling resistance is closely related to the weight of the 
vehicle. Therefore, we propose that the vehicle-based standards for 
these trucks vary according to one key attribute, GVWR. For this 
initial HD rulemaking, we propose that these standards be 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 proposed vehicle-based standards 
because they parallel the general divisions among key engine 
characteristics, as discussed in Section II.
    The agencies intend to monitor the development of and production 
feasibility of new vehicle-related GHG and fuel consumption reduction 
improving technologies and consider including these technologies in 
future rulemakings. As discussed below, 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. We also are proposing a mechanism whereby credits can 
be generated by use of other technologies not included in the 
compliance model. (See Sections I.E and IV below.)
    Table I-3 presents EPA's proposed CO2 standards and 
NHTSA's proposed fuel consumption standards for chassis manufacturers 
of Class 2b through Class 8 vocational vehicles for the 2017 model year 
for illustrative purposes.
[GRAPHIC] [TIFF OMITTED] TP30NO10.004

    At this time, NHTSA and EPA are not prepared to propose alternative 
standards based on a whole-vehicle chassis test for vocational vehicles 
in this initial heavy-duty rulemaking. As discussed above for 
combination tractors, the primary reason is the very small number of 
chassis-test facilities that currently exist. Thus, the agencies are 
proposing only the compliance-model based standards and engine 
standards discussed above, and seek comment on the appropriateness of 
chassis-test-based standards for the vocational vehicle category.
    For vocational vehicles using hybrid technology, the agencies are 
proposing two specialized approaches to allow manufacturers to gain 
credit for the emissions and fuel consumption reductions associated 
with hybrid technology. One option to account for the reductions 
associated with vocational vehicles using hybrid technology would 
compare vehicle-based chassis tests with and without the hybrid 
technology. The other option would allow a manufacturer to simulate the 
operation of the hybrid system in an engine-based test. The options are 
further discussed in Section IV.
    The proposed program also provides for opportunities to generate 
credits for technologies not measured by the GEM, again described more 
fully in Section IV.
    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 is not proposing separate vehicle-based 
standards for these GHGs, but is proposing engine-based N2O 
and CH4 standards for manufacturers of the engines to be 
used in vocational vehicles. EPA expects that

[[Page 74167]]

manufacturers of current engine technologies would be able to comply 
with the proposed ``cap'' standards with little or no technological 
improvements; the value of the standards would be in that they would 
prevent significant increases in these emissions as alternative 
technologies are developed and introduced in the future. Compliance 
with the proposed EPA engine-based CO2 standards and the 
proposed NHTSA fuel consumption standards, as well as the proposed EPA 
N2O and CH4 standards, would 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 proposing standards that would apply to Class 2b-8 
vocational vehicles at the time of production, and EPA is proposing 
standards for a specified period of time in use. All of the proposed 
standards for these trucks, as well as details about the proposed 
provisions for certification and implementation of these standards, are 
discussed in more detail later in this notice and in the draft RIA.
    EPA is not proposing A/C refrigerant leakage standards for Class 
2b-8 vocational vehicles at this time, 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. EPA requests comment on how 
A/C standards might practically be applied to manufacturers of 
vocational vehicles.
(d) What Manufacturers Are Not Covered by the Proposed Standards?
    EPA and NHTSA are proposing to temporarily defer the proposed 
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. We are not aware of any manufacturers of HD pickups and 
vans that meet these criteria. For each of the other categories and for 
engines, we have identified a small number of manufacturers that would 
appear to qualify as small businesses. The production of these 
companies is small, and we believe 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. We request comment on our assumption that the 
impact of these exemptions for small businesses will be small and 
further whether it will be possible to circumvent the regulations by 
creating new small businesses to displace existing manufacturers. We 
discuss the specific deferral provisions 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.

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

    This section summarizes the projected costs and benefits of the 
proposed NHTSA fuel consumption and EPA GHG emissions standards. These 
projections help to inform the agencies' choices among the alternatives 
considered and provide further confirmation that the proposed 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 and 
benefits of the proposed GHG and fuel consumption standards. Table I-4 
shows estimated lifetime discounted costs, benefits and net benefits 
for all heavy-duty vehicles projected to be sold in model years 2014-
2018. These figures depend on estimated values for the social cost of 
carbon (SCC), as described in Section VIII.G.
[GRAPHIC] [TIFF OMITTED] TP30NO10.005


[[Page 74168]]


    Table I-5 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-5 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-5 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.007

    Table I-6 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 2008 dollars and 2010 
emissions. Table I-6 presents benefits based on the $22 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 fuel savings, energy security, 
and other externalities such as reduced accidents, congestion and 
noise. However, the analysis supporting the proposal omits other 
impacts such as benefits related to non-GHG emission reductions. The 
lifetime discounted benefits are shown for one of four different SCC 
values considered by EPA and NHTSA. The values in Table I-6 do not 
include costs associated with new technology required to meet the GHG 
and fuel consumption standards.
[GRAPHIC] [TIFF OMITTED] TP30NO10.008

    Table I-7 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 estimated fuel savings in billions of barrels and the 
GHG reductions in million metric tons of CO2 shown in Table 
I-7 are totals for the five model years throughout their projected 
lifetime and are not discounted. The monetized values shown in Table I-
7 are the summed values of the discounted monetized-fuel consumption 
and

[[Page 74169]]

monetized-CO2 reductions for the five model years 2014-2018 
throughout their lifetimes. The monetized values in Table I-7 reflect 
both a 3 percent and a 7 percent discount rate as noted.
[GRAPHIC] [TIFF OMITTED] TP30NO10.009

    Table I-8 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-8 are for the industry as 
a whole and do not account for fuel savings associated with the 
program.
[GRAPHIC] [TIFF OMITTED] TP30NO10.010

    Table I-9 shows EPA's estimated incremental cost increase of the 
average new heavy-duty vehicles for each model year 2014-2018. The 
values shown are incremental to a baseline vehicle and are not 
cumulative.
[GRAPHIC] [TIFF OMITTED] TP30NO10.011

BILLING CODE 6560-50-C

E. Program Flexibilities

    For each of the heavy-duty vehicle and heavy-duty engine categories 
for which we are proposing respective standards, EPA and NHTSA are also 
proposing provisions designed to give manufacturers a degree of 
flexibility in complying with the standards. These proposed provisions 
have enabled the agencies to consider overall standards that are more 
stringent and that would 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.\30\ 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.
---------------------------------------------------------------------------

    \30\ 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 proposed flexibility provisions are essentially 
identical to each other in structure and function. For combination 
tractor and vocational vehicle categories and for heavy-duty engines, 
we are proposing 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 proposed ABT provisions are patterned on 
existing EPA ABT programs and would allow a vehicle manufacturer to 
reduce CO2 emission and fuel consumption levels

[[Page 74170]]

further than the level of the standard for one or more vehicles to 
generate ABT credits. The manufacturer could then use those credits to 
offset higher emission or fuel consumption levels in other similar 
vehicles, ``bank'' the credits for later use, or ``trade'' the credits 
to another manufacturer. We are proposing similar ABT provisions for 
manufacturers of heavy-duty engines. For HD pickups and vans, we are 
proposing a fleet averaging system very similar to the light-duty GHG 
and CAFE fleet averaging system.
    To best ensure that the overall emission and fuel consumption 
reductions of the program would be achieved and to minimize any effect 
on the ability of the market to respond to consumer needs, the agencies 
propose to restrict the use of averaging to limited sets of vehicles 
and engines expected to have similar emission or fuel consumption 
characteristics. For example, averaging would be allowed among Class 7 
low-roof day cab vehicles, but not among those vehicles and Class 8 
sleeper cabs or vocational vehicles. Also, we propose that credits 
generated by vehicles not be applicable to engine compliance, and vice 
versa. For HD pickups and vans, we propose that fleet averaging be 
allowed with minimum restriction within the HD pickup and van category.
    In addition to ABT, the agencies are proposing that a manufacturer 
that reduces CO2 emissions and fuel consumption below 
required levels prior to the beginning of the program be allowed to 
generate the same number of credits (``early credits'') that they would 
after the program begins.
    The agencies are also proposing that manufacturers that show 
improvements in CO2 emissions and fuel consumption and 
incorporate certain technologies (including hybrid powertrains, Rankine 
engines, or electric vehicles) be eligible for special ``advanced 
technology'' credits. Unlike other credits in this proposal, the 
advanced technology credits could be applied to any heavy-duty vehicle 
or engine, and not be limited to the vehicle category generating the 
credit.
    The technologies eligible for advanced technology credits above 
lend themselves to straightforward methodologies for quantifying the 
emission or fuel consumption reductions. 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 seek to encourage the development of such innovative 
technologies, and are therefore proposing special ``innovative 
technology'' credits. These innovative technology credits would 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. Manufacturers would 
need to quantify the reductions in fuel consumption and CO2 
emissions that the technology could achieve, above and beyond those 
achieved on the existing test procedures. As with ABT, we propose that 
the use of innovative technology credits be only allowed among vehicles 
and engines expected to have similar emissions and fuel consumption 
characteristics (e.g., within each of the nine Class 7 & 8 combination 
tractor subcategories, or within each of the three Class 2b-8 
vocational vehicle subcategories).
    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 proposal implements a specific provision from Title II, 
section 202(a).\31\ 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 for greenhouse gases, section 202(a) authorizes EPA 
to issue standards applicable to emissions of those pollutants from new 
motor vehicles.
---------------------------------------------------------------------------

    \31\ See 42 U.S.C. 7521(a).
---------------------------------------------------------------------------

    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); 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

[[Page 74171]]

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 the 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)). 
EPA has interpreted a similar statutory provision, CAA section 231, as 
follows:
    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' ''). Also see 
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)).
    (b) 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
    EISA authorizes NHTSA to create a fuel efficiency improvement 
program for ``commercial medium- and heavy-duty on-highway vehicles and 
work trucks'' \32\ 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.
---------------------------------------------------------------------------

    \31\ ``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).
---------------------------------------------------------------------------

    Since this is the first rulemaking that NHTSA has conducted under 
49 U.S.C. 32902(k)(2), the agency must interpret these elements and 
factors in the context of setting standards, choosing metrics, and 
determining test methods and compliance/enforcement mechanisms. 
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. section 
32902(k). See 49 U.S.C. section 32902(b)(1). We note that 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. section 32902(b)(3)(B). For purposes of the 
fuel efficiency standards that the agency is proposing for HD vehicles 
and engines, NHTSA believes that one permissible reading of the statute 
is that Congress did not intend for the 5-year maximum limit to apply 
to standards promulgated in accordance with 49 U.S.C. section 32902(k), 
given the language in

[[Page 74172]]

32902(b)(1). Based on this interpretation, NHTSA proposes 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 seeks comment on this interpretation of 
EISA.
(a) NHTSA Testing Authority
    49 U.S.C. 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.
(b) NHTSA Enforcement Authority
    49 U.S.C. 32902(k)(2) also states that NHTSA must adopt and 
implement appropriate, cost-effective, and technologically feasible 
compliance and enforcement protocols for the fuel efficiency 
improvement program.
    In 49 U.S.C. 32902(k)(2), Congress did not speak directly to the 
``compliance and enforcement protocols'' it envisioned. Instead, it 
left the matter generally to the Secretary. Congress' approach is 
unlike CAFE enforcement for passenger cars and light trucks, where 
Congress specified a program where a manufacturer either complies with 
standards or pays civil penalties. But Congress did not specify in 49 
U.S.C. 32902(k) what it precisely meant in directing NHTSA to develop 
``compliance and enforcement protocols.'' It appears, therefore, that 
Congress has assigned this matter to the agency's discretion.
    The statute is silent with respect to how ``protocol'' should be 
interpreted. The term ``protocol'' is imprecise. 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).\33\ 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.
---------------------------------------------------------------------------

    \33\ 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 interprets ``protocol'' in the context of EISA as authorizing 
the agency to determine both whether manufacturers have complied with 
the standards, and to establish the enforcement mechanisms and decision 
criteria for non-compliance. NHTSA seeks comment on its interpretation 
of this statutory requirement.

G. Future HD GHG and Fuel Consumption Rulemakings

    This proposal 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 propose 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 timeframe, our proposal is 
very aggressive--with limited lead time compared to historic heavy-duty 
regulations--but pragmatic in the context of technologies that are 
available.
    While we are now only proposing this first step, it is worthwhile 
to consider how future regulations that may follow this step may be 
constructed. 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 would not be necessary 
to meet the proposed standards, which are premised on the use of 
existing technologies. When we begin our future 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 proposing 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 criteria and 
GHG emissions. However, we believe the important issues and technical 
work related to setting new criteria emissions standards appropriate 
for the World Harmonized Duty Cycle are significant and beyond the 
scope of this rulemaking. Therefore, the agencies are not proposing to 
adopt these test procedures in this proposal, but we are ready to work 
with interested stakeholders to adopt these procedures in a future 
action.
    As with this proposal, 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.

[[Page 74173]]

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

    This section describes the standards and implementation dates that 
the agencies are proposing for the three categories of heavy-duty 
vehicles. The agencies have performed a technology analysis to 
determine the level of standards that we believe would be appropriate, 
cost-effective, and feasible during the rulemaking timeframe. This 
analysis, described in Section III and in more detail in the draft RIA 
Chapter 2, considered:
     The level of technology that is incorporated in current 
new trucks,
     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 2018 model year,
     The effectiveness and cost of these technologies,
     Projections of future U.S. sales for trucks, and
     Forecasts of manufacturers' product redesign schedules.

A. What vehicles would be affected?

    EPA and NHTSA are proposing standards for heavy-duty engines and 
also for what we refer to generally as ``heavy-duty trucks.'' As noted 
in Section I, for purposes of this preamble, the term ``heavy-duty'' or 
``HD'' is used to apply 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 
proposed 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.\34\ 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.\35\ Therefore, the term 
``heavy-duty trucks'' in this proposal refers to both work trucks and 
commercial medium- and heavy-duty on-highway vehicles as defined by 
EISA. Heavy-duty engines affected by the proposed standards are those 
that are installed in commercial medium- and heavy-duty trucks, 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. EPA is proposing to include 
recreational on-highway vehicles within their rulemaking, while NHTSA 
is limiting their scope to commercial trucks which would not include 
these vehicles.
---------------------------------------------------------------------------

    \34\ Codified at 49 U.S.C. 32901(a)(7).
    \35\ 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., pick-up 
box or bed) of six feet or more in interior length. (See the Tier 2 
final rulemaking, 65 FR 6698, February 10, 2000.)
---------------------------------------------------------------------------

    EPA and NHTSA are proposing standards for each of the following 
categories, which together comprise all heavy-duty vehicles and all 
engines used in such vehicles.\36\ In order to most appropriately 
regulate the broad range of heavy-duty vehicles, the agencies are 
proposing to set separate engine and vehicle standards for the 
combination tractors and the Class 2b through 8 vocational vehicles and 
the engines installed in them. The engine standards and test procedures 
for engines installed in the tractors and vocational vehicles are 
discussed within the applicable vehicle sections.
---------------------------------------------------------------------------

    \36\ Both agencies have authority to develop separate standards 
for vehicle and engine categories, as appropriate. See CAA section 
202(a)(1) (authority to establish standards for ``any class or 
classes of new motor vehicles or engines'' and 49 U.S.C 32902(k)(2) 
(authority to establish standards for HD vehicles that are 
``appropriate, cost-effective, and technologically feasible'' that 
are designed to achieve the ``maximum feasible improvement'' in fuel 
efficiency; authority to establish ``separate standards for 
different classes of vehicles under this subsection.'' NHTSA 
interprets 49 U.S.C. 32902(k)(2) to include a grant of authority to 
establish engines standards pursuant to the broader statement of 
authority to establish standards that achieve the maximum feasible 
improvement in fuel efficiency.
---------------------------------------------------------------------------

     Class 7 and 8 Combination Tractors.
     Heavy-Duty Pickup Trucks and Vans.
     Class 2b through 8 Vocational Vehicles.
    As discussed in Section IX, the agencies are not proposing GHG 
emission and fuel consumption standards for trailers at this time. In 
addition, the agencies are proposing to not set standards at this time 
for engine, chassis, and vehicle manufacturers which are small 
businesses (as defined). More detailed discussion of each regulatory 
category is included in the subsequent sections below.

B. Class 7 and 8 Combination Tractors

    EPA is proposing CO2 standards and NHTSA is proposing 
fuel consumption standards for new Class 7 and 8 combination tractors. 
The standards are for the tractor cab, with a separate standard for the 
engines that are installed in the tractor. Together these standards 
would achieve reductions up to 20 percent from tractors. As discussed 
below, EPA is proposing to adopt the existing useful life definitions 
for heavy-duty engines for the Class 7 and 8 tractors. NHTSA is 
proposing fuel consumption standards for tractors, and engine standards 
for heavy-duty engines for Class 7 and 8 tractors. The agencies' 
analyses, as discussed briefly below and in more detail later in this 
preamble and in the draft RIA Chapter 2, show that these standards are 
appropriate and feasible under each agency's respective statutory 
authorities.
    EPA is also proposing standards to control N2O, 
CH4, and HFC emissions from Class 7 and 8 combination 
tractors. The proposed heavy-duty engine standards for both 
N2O and CH4 and details of the standard are 
included in the discussion in Section II. The proposed air conditioning 
leakage standards applying to tractor manufacturers to address HFC 
emissions are included in Section II.
    The agencies are proposing CO2 emissions and fuel 
consumption standards for the combination tractors that will focus on 
reductions that can be achieved through improvements in the tractor 
(such as aerodynamics), tires, and other vehicle systems. The agencies 
are also proposing heavy-duty engine standards for CO2 
emissions and fuel consumption that would focus on potential 
technological improvements in fuel combustion and overall engine 
efficiency.
    The agencies have analyzed the feasibility of achieving the 
CO2 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

[[Page 74174]]

standards in Section III. In developing the proposed 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 CO2 and fuel savings that may be achieved.
    EPA and NHTSA are proposing attribute-based standards for the Class 
7 and 8 combination tractors, or, put another way, we are proposing to 
set 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 
recent light-duty vehicle fuel economy and GHG rule, in which the 
standards are based on the attribute of vehicle ``footprint,'' the 
existing heavy-duty highway engine criteria pollutant emission 
standards for many years have been based on a vehicle weight attribute 
(Light Heavy, Medium Heavy, Heavy Heavy) with different useful life 
periods, which is the same approach proposed for the engine GHG and 
fuel consumption standards discussed below.
    Heavy-duty combination tractors are built to move freight. The 
ability of a truck 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 combined 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 80,000 
pound GCWR. Consistent with the recommendation in the National Academy 
of Sciences 2010 Report to NHTSA,\37\ the agencies are proposing 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 trucks have better specific fuel consumption 
and GHG emissions than lower payload capacity trucks. Therefore, since 
the amount of payload that a Class 7 truck can carry is less than the 
Class 8 truck'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 proposing separate standards for 
Class 7 and Class 8 tractors.
---------------------------------------------------------------------------

    \37\ See 2010 NAS Report, Note 19, Recommendation 2-1.
---------------------------------------------------------------------------

    The agencies are not proposing to set 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 is 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 vehicle 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 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 proposing that the roof height of the tractor determine 
the trailer type required to be used to demonstrate compliance of a 
truck 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 customarily tied 
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.\38\ Therefore,

[[Page 74175]]

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 proposing to create separate standards 
for sleeper cabs and day cabs.
---------------------------------------------------------------------------

    \38\ 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).
---------------------------------------------------------------------------

    To account for the relevant combinations of these attributes, the 
agencies therefore propose to segment 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

    The agencies have not identified any Class 7 or Class 8 day cabs 
with mid roof heights in the market today but welcome comments with 
regard to this market characterization.
    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. The agencies propose to treat tractors with 
adjustable roof fairings as low roof tractors and test with the fairing 
down. The agencies welcome comments on this approach and data to 
support whether to allow additional credits for their use.
    The agencies are proposing to classify all vehicles with sleeper 
cabs as tractors. The proposed rules would not allow vehicles with 
sleeper cabs to be classified as vocational vehicles. This provision is 
intended prevent the initial manufacture of straight truck vocational 
vehicles with sleeper cabs that, soon after introduction into commerce, 
would be converted to combination tractors, as a means to circumvent 
the Class 8 sleeper cab regulations. The agencies welcome comments on 
the likelihood of manufacturers using such an approach to circumvent 
the regulations and the appropriate regulatory provisions the agencies 
should consider to prevent such actions.
(1) What are the proposed Class 7 and 8 tractor and engine 
CO2 emissions and fuel consumption standards and their 
timing?
    In developing the proposed tractor and engine standards, 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 engines, 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. The 
technologies that the agencies considered while setting the proposed 
tractor standards include improvements in aerodynamic design, lower 
rolling resistance tires, extended idle reduction technologies, and 
vehicle empty weight reduction. The technologies that the agencies 
considered while setting the engine standards include engine friction 
reduction, aftertreatment optimization, and turbocompounding, among 
others. The agencies' evaluation indicates that these technologies are 
available today, but have very low application rates in the market. The 
agencies have analyzed the technical feasibility of achieving the 
proposed CO2 and fuel consumption standards for tractors and 
engines, based on projections of what actions manufacturers would be 
expected to take to reduce emissions and fuel consumption to achieve 
the standards. 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 draft RIA Chapter 2.
(a) Tractor Standards
    The agencies are proposing the following standards for Class 7 and 
8 combination tractors in Table II-1, using the subcategorization 
approach just explained. As noted, the agencies are not aware of any 
mid roof day cab tractors at this time, but are proposing that any 
Class 7 and 8 day cabs with a mid roof would meet the respective low 
roof standards, based on the similarity in baseline performance and 
similarity in expected improvement of mid roof sleeper cabs relative to 
low roof sleeper cabs.
    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 
proposing standards starting for that model year predicated on 
performance of those technologies. EPA is proposing more stringent 
tractor standards for the 2017 model year which reflect the 
CO2 emissions reductions required through the 2017 model 
year engine standards. (As explained in Section II.B.(2)(h)(v) below, 
engine performance is one of the inputs into the proposed 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 
proposed standards apply throughout the useful life period as described 
in Section V. Similar to EPA's non-GHG standards approach, 
manufacturers may generate and use credits from Class 7 and 8 
combination tractors to show compliance with the standards.
    NHTSA is proposing 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 and stability requirement within EISA. NHTSA is also 
proposing new standards for the 2017 model year which reflect 
additional improvements in only the heavy-duty engines. While NHTSA 
proposes to 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 currently anticipated there will be 
notable deterioration of fuel consumption over the useful life. NHTSA 
believes that the vehicle and engine standards proposed for combination 
tractors are appropriate, cost-effective, and technologically feasible 
in the rulemaking timeframe based on our analysis detailed below in 
Section III and in the Chapter 2 of the draft RIA.
    EPA and NHTSA are not proposing to make the 2017 vehicle standards 
more stringent based on the application of additional truck 
technologies because projected application rates of truck technologies 
used in setting the 2014 model year truck standard already reflect the 
maximum application rates we believe appropriate for these vehicles 
given their specific use patterns as described in Section III. We 
considered setting more stringent standards for Class 7 and 8 tractors 
based on the application of more advanced aerodynamic systems, such as 
self-compensating side extenders or other advanced aerodynamic 
technologies, but concluded that those

[[Page 74176]]

technologies would not be fully developed in the necessary lead time. 
We request comment on this decision, supported by data as appropriate.
[GRAPHIC] [TIFF OMITTED] TP30NO10.012

    Based on our analysis, the 2017 model year standards represent up 
to a 20 percent reduction in CO2 emissions and fuel 
consumption over a 2010 model year baseline, as detailed in Section 
III.A.2.
---------------------------------------------------------------------------

    \39\ Manufacturers may voluntarily opt-in to the NHTSA fuel 
consumption program in 2014 or 2015. If a manufacturer opts-in, the 
program becomes mandatory. See Section [add cross reference] below 
for more information about NHTSA's voluntary opt-in program for MYs 
2014 and 2015.
---------------------------------------------------------------------------

(i) Off-Road Tractor Standards
    In developing the proposal EPA and NHTSA received comment from 
manufacturers and owners that tractors sometimes have very limited on-
road usage. These trucks are defined to be motor vehicles under 40 CFR 
85.1703, but they will spend the majority of their operations off-road. 
Tractors, such as those used in oil fields, will experience little 
benefit from improved aerodynamics and low rolling resistance tires. 
The agencies are therefore proposing to allow a narrow range of these 
de facto off-road trucks to be excluded from the proposed tractor 
standards because the trucks do not travel at speeds high enough to 
realize aerodynamic improvements and require special off-road tires 
such as lug tires. The trucks must still use a certified engine, which 
will provide fuel consumption and CO2 emission reductions to 
the truck in all applications. To ensure the limited use of these 
trucks, the agencies are proposing requirements that the vehicles have 
off-road tires, have limited high speed operation, and are designed for 
specific off-road applications.\40\ The agencies are proposing that a 
truck must meet the following requirements to qualify for an exemption 
from the vehicle standards for Class 7 and 8 tractors:
---------------------------------------------------------------------------

    \40\ For purposes of compliance with NHTSA's safety regulations, 
such as FMVSS Nos. 119 and 121, a manufacturer wishing for their 
vehicle to classify as ``off-road'' would still need to work with 
the relevant NHTSA office to declare its vehicle as ``off-road'' if 
it uses public roads at any point in its service.
---------------------------------------------------------------------------

     Installed tires which are lug tires or contain a speed 
rating of less than or equal to 60 mph; and
     Include a vehicle speed limiter governed to 55 mph, and
     Contain Power Take-Off controls, or have axle 
configurations other than 4x2, 6x2, or 6x4 and has GVWR greater than 
57,000 pounds; and
     Has a frame Resisting Bending Moment greater than 
2,000,000 lb-in.\41\
---------------------------------------------------------------------------

    \41\ 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.
---------------------------------------------------------------------------

    EPA and NHTSA have concluded that the onroad performance losses and 
additional costs to develop a truck which meets these specifications 
will limit the exemption to trucks built for

[[Page 74177]]

the desired purposes.\42\ The agencies welcome comment on the proposed 
requirements and exemptions.
---------------------------------------------------------------------------

    \42\ The estimated cost for a lift axle is approximately 
$10,000. Axles with weight ratings greater than a typical on-road 
axle cost an additional $3,000.
---------------------------------------------------------------------------

(b) Engine Standards
    EPA is proposing GHG standards and NHTSA is proposing fuel 
consumption standards for new heavy-duty engines. The standards will 
vary depending on the type of vehicle in which they are used, as well 
as whether the engines are diesel or gasoline powered. This section 
discusses the standards for engines used in Class 7 and 8 combination 
tractors and also provides some overall background information. More 
information is also provided in the discussion of the standards for 
engines used in vocational vehicles.
    EPA's existing criteria pollutant emissions regulations for heavy-
duty highway engines establish four regulatory categories that 
represent the engine's intended and primary truck application.\43\ 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 regulatory subcategory. The engines in 
these four regulatory subcategories range in size between approximately 
five liters and sixteen liters. The agencies welcome comments on 
updating the definitions of each subcategory, such as the typical 
horsepower levels, as described in 40 CFR 1036.140.
---------------------------------------------------------------------------

    \43\ See 40 CFR 1036.140.
---------------------------------------------------------------------------

    For the purposes of the GHG engine emissions and engine fuel 
consumption standards that EPA and NHTSA are proposing, the agencies 
intend to maintain these same four regulatory subcategories. This class 
structure would enable the agencies to set standards that appropriately 
reflect the technology available for engines for use in each type of 
vehicle, and that are therefore technologically feasible for these 
engines. This section discusses the MHD and HHD diesel engines used in 
Class 7 and 8 combination tractors. Additional details regarding the 
other heavy-duty engine standards are included in Section II.D.1.b.
    EPA's proposed heavy-duty CO2 emission standards for 
diesel engines installed in combination tractors are presented in Table 
II-2. We should note that this does not cover gasoline or LHDD engines 
as they are not used in Class 7 and 8 combination tractors. Similar to 
EPA's non-GHG standards approach, manufacturers may generate and use 
credits to show compliance with the standards. EPA is proposing to 
adopt the existing useful life definitions for heavy-duty engines. The 
EPA standards would become effective in the 2014 model year, with more 
stringent standards becoming effective in model year 2017. Recently, 
EPA's heavy-duty highway engine program for criteria pollutants 
provided new emissions standards for the industry in three year 
increments. Largely, the heavy-duty engine and truck manufacturer 
product plans have fallen into three year cycles to reflect this 
regulatory environment. The proposed two-step CO2 emission 
standards recognize the opportunity for technology improvements over 
this timeframe while reflecting the typical diesel truck manufacturers' 
product plan cycles.
    With respect to the lead time and cost of incorporating technology 
improvements that reduce GHG emissions and fuel consumption, EPA and 
NHTSA place important weight on the fact that during MYs 2014-2017 
engine manufacturers are expected to redesign and upgrade their 
products. 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 proposed 
GHG and fuel consumption reductions, and to do this as part of the 
normal engine redesign process. This is an important aspect of the 
proposed 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. 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.
    NHTSA's fuel consumption standards, also presented in Table II-2, 
would contain voluntary engine standards starting in 2014 model year, 
with mandatory engine standards starting in 2017 model year, harmonized 
with EPA's 2017 model year standards. A manufacturer may opt-in to 
NHTSA's voluntary standards in 2014, 2015 or 2016. Once a manufacturer 
opts-in, the standards become mandatory for the opt-in and subsequent 
model years, and the manufacturer may not reverse its decision. To opt 
into the program, a manufacturer must declare its intent to opt in to 
the program at the same time it submits the Pre-Certification 
Compliance Report. See 49 CFR 535.8 for information related to the Pre-
Certification Compliance Report. A manufacturer opting into the program 
would begin tracking credits and debits beginning in the model year in 
which they opt into the program.

[[Page 74178]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.013

    Combination 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 would be required to meet the standard based on 
the steady-state SET test cycle, as discussed further in Section 
II.B(2)(i).
    The baseline HHD diesel engine performance in 2010 model year 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. Similarly, 
the baseline MHD diesel engine performance on the SET cycle is 518 g 
CO2/bhp-hr (5.09 gallon/100-bhp-hr) in the 2010 model year. 
Further discussion of the derivation of the baseline can be found in 
Section III The diesel engine standards that EPA is proposing and the 
voluntary standards being proposed by NHTSA for the 2014 model year 
would require diesel engine manufacturers to achieve on average a three 
percent reduction in fuel consumption and CO2 emissions over 
the baseline 2010 model year performance for the engines. The agencies' 
assessment of the findings of the 2010 NAS Report and other literature 
sources indicates that there are technologies available to reduce fuel 
consumption by this level in the proposed timeframe. These technologies 
include improved turbochargers, aftertreatment optimization, low 
temperature exhaust gas recirculation, and engine friction reductions. 
Additional discussion on technical feasibility is included in Section 
III below and in draft RIA Chapter 2.
    Furthermore, the agencies are proposing that diesel engines further 
reduce fuel consumption and CO2 emissions from the 2010 
model year baseline in 2017 model year. The proposed reductions 
represent on average a six percent reduction for MHD and HHD diesel 
engines required to use the SET-based standard. The additional 
reductions could likely be achieved through the increased refinement of 
the technologies projected to be implemented for 2014, plus the 
addition of turbocompounding or other waste heat recovery systems. The 
agencies' analysis indicates that this type of advanced engine 
technology would require a longer development time than the 2014 model 
year, and we therefore are proposing to provide additional lead time to 
allow for its introduction.
    The agencies are aware that some truck and engine manufacturers 
would prefer to align their product development plans for these engine 
standards with their current plans to meet Onboard Diagnostic 
regulations for EPA and California in 2013 and 2016. We believe our 
proposed averaging, banking and trading provisions already provide 
these manufacturers with considerable flexibility to manage their GHG 
compliance plans consistent with the 2013 model year. Nevertheless, we 
are requesting comment on whether EPA and NHTSA should provide 
additional defined phase-in schedules that would more explicitly 
accommodate this request. For example, we request comment on a phase-in 
schedule with a standard of 485 g/bhp-hr for the model years 2013-2015 
followed by a standard of 460 g/bhp-hr for 2016-18 model years with the 
associated fuel consumption values for the NHTSA program. This phase-in 
schedule is just one of many potential schedules that would provide 
identical fuel savings and emissions reductions for the period from 
2013-2018. If commenters wish to discuss a different phase-in schedule 
than the one proposed by the agencies, we request that commenters 
include a description of their preferred phase-in schedule, including 
an analysis showing that it would be at least as effective (or more) as 
the primary program for the period through the 2018 model year. We also 
request comment on whether similar provisions should be made for the 
vocational engine standards discussed later in this section.
    In proposing this standard for heavy-duty diesel engines used in 
Class 7 and 8 combination tractors, the agencies have examined the 
current performance levels of the engines across the fleet. EPA and 
NHTSA found that a large majority of the engines were generally 
relatively close to the average baseline, with some above and some 
below. We recognize, however, that when regulating a category of 
engines for the first time, there will be individual products that may 
deviate significantly from this baseline level of performance. For the 
current fleet there is a relatively small group of engines that are 
significantly worse than the average baseline for other engines. In 
proposing the standards, the agencies have looked primarily at the 
typical performance levels of the majority of the engines in the fleet, 
and the increased performance that would be achieved through increased 
spread of technology. The agencies also recognize that for the smaller 
group of products, the same reduction from the industry baseline may 
experience significant issues of available lead-time and cost because 
these products may require a total redesign in order to meet the 
standards. These are limited instances where certain engine families 
have high atypically high baseline CO2 levels and limited 
line of engines across which to average performance. See 75 FR 25414-
25419, which adopts temporary lead time allowance alternative standards 
to

[[Page 74179]]

deal with a similar issue for a subset of light-duty vehicles. To 
accommodate these situations, the agencies are proposing a regulatory 
alternative whereby a manufacturer, for a limited period, 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, rather than meeting the otherwise-applicable standard 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. We 
do not believe this alternative needs to continue past the 2016 model 
year since manufacturers will have had ample opportunity to benchmark 
competitive products during redesign cycles and to make appropriate 
changes to bring their product performance into line with the rest of 
the industry. This 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. We are proposing that manufacturers can select engine 
families for this alternative standard without agency approval, but are 
proposing to require that manufacturers notify the agency of their 
choice and to include in that notification a demonstration that it has 
exhausted all available credits and credit opportunities.
    The agencies are also requesting comment on the potential to extend 
this regulatory alternative for one additional year for a single engine 
family with performance measured in that year as six percent beyond the 
engine's own 2011 baseline level. We also request comment on the level 
of reduction beyond the baseline that is appropriate in this 
alternative. The three percent level reflects the aggregate improvement 
beyond the baseline we are requiring of the entire industry. As this 
provision is intended to address potential issues for legacy products 
that we would expect to be replaced or significantly improved at the 
manufacturer's next product redesign, we request comment if a two 
percent reduction would be more appropriate. We would consider two 
percent rather than three percent if we were convinced that making all 
of the changes we have outlined in our assessment of the technical 
feasibility of the standards was not possible for some engines due to 
legacy design issues that will change in the future. We are proposing 
that manufacturers making use of these provisions would need to exhaust 
all credits within this subcategory prior to using this flexibility and 
would not be able to generate emissions credits from other engines in 
the same regulatory subcategory as the engines complying using this 
alternate approach.
    EPA and NHTSA considered setting even more stringent engine 
standards for the 2017 model year based on the use of more 
sophisticated waste heat recovery technologies such as bottoming cycle 
engine designs. We are not proposing more stringent standards because 
we do not believe this technology can be broadly available by 2017 
model year. We request comment on the technological feasibility and 
cost-effectiveness of more stringent standards in the timeframe of the 
proposed standards.
(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 proposing would apply to 
individual vehicles and engines. NHTSA is not proposing to adopt in-
use.
    EPA is proposing 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. EPA is proposing a 2 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. Details on the 
development of the adjustment factor are included in draft RIA Chapter 
3.
    EPA is also proposing 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 proposes that the 
existing engine useful life periods, as included in Table II-3:, be 
broadened to include CO2 emissions and fuel consumption for 
both engines and tractors (see 40 CFR 86.004-2).
[GRAPHIC] [TIFF OMITTED] TP30NO10.014

    EPA and NHTSA request comments on the magnitude and need for an in-
use adjustment factor for the engine standard and the compliance model 
(GEM) based tractor standard.
(2) Test Procedures and Related Issues
    The agencies are proposing 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. The test procedures 
related to the tractors are all new, while the engine test procedures 
build substantially on EPA's current non-GHG emissions test procedures, 
except as noted. This section discusses the proposed simulation model 
developed for demonstrating compliance with the tractor standard and 
the proposed engine test procedures.
(a) Truck Simulation Model
    We are proposing to set separate engine and vehicle-based emission 
standards to achieve the goal of reducing emissions and fuel 
consumption for both trucks and engines. For the Class 7 and 8 
tractors, engine manufacturers would be subject to the engine 
standards, and Class 7 and 8 tractor manufacturers would be required to 
install engines in their tractors certified for use in the tractor. The 
tractor manufacturer would be subject to a separate vehicle-based 
standard that would use a proposed truck simulation model to evaluate 
the

[[Page 74180]]

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.
    NHTSA and EPA are proposing 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 agencies developed the 
Greenhouse gas Emissions Model (GEM) for the specific purpose of this 
proposal 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 agencies and proposed 
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 draft 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 welcome comments on other simulation tools which 
could be used by the agencies. The use criteria for this model are that 
it must be able to be managed by the agencies for compliance purposes, 
has no cost to the end-user, is freely available and distributable as 
an executable file, contains open source code to provide transparency 
in the model's operation yet contains features which cannot be changed 
by the user, and is easy to use by any user with minimal or no prior 
experience.
    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 GEM based on the chassis test results from a 
SmartWay certified tractor tested at Southwest Research Institute. The 
validation work conducted on these three vehicles is 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 4 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 proposing to utilize in 
compliance testing. Test to test variation for heavy-duty vehicle 
chassis testing can be higher than 4 percent based on driver variation. 
The proposed simulation model is described in greater detail in Chapter 
4 of the draft RIA and is available for download by interested parties 
at (http://www.epa.gov/otaq/climate/regulations.htm). We request 
comment on all aspects of this approach to compliance determination in 
general and to the use of the GEM in particular.
    The agencies are proposing that for demonstrating compliance, a 
Class 7 and 8 tractor manufacturer would measure the performance of 
specified tractor systems (such as aerodynamics and tire rolling 
resistance), input the values into GEM, and compare the model's output 
to the standard. The agencies propose that a tractor manufacturer would 
provide the inputs for each of following factors for each of the 
tractors it wished 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-3.
    The input values for the simulation model would be derived by the 
manufacturer from test procedures proposed by the agencies in this 
proposal. The agencies are proposing several testing alternatives for 
aerodynamic assessment, a single procedure for tire rolling resistance 
coefficient determination, and a prescribed method to determine tractor 
weight reduction. The agencies are proposing 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 proposing standards for Class 7 and 8 
combination tractors that would be expressed in terms of moving a ton 
(2000 pounds) of freight over one mile. Thus, NHTSA's proposed 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 proposed CO2 vehicle standards would be 
represented as grams of CO2 per ton-mile.
    Similarly, 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

[[Page 74181]]

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 proposing, 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 
proposed 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 tractor can go up. Based on this general approach, it can 
be estimated that for every 1,200 pounds in mass reduction total truck 
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 truck. The agencies seek comment on the use of a per ton-
mile metric and also whether other metrics such as per cube-mile should 
be considered instead.
(c) Truck Aerodynamic Assessment
    The aerodynamic drag of a vehicle is determined by the vehicle's 
coefficient of drag (Cd), frontal area, air density and speed. The 
agencies are proposing to establish and use pre-defined values for the 
input parameters to GEM which represent the frontal area and air 
density, while the speed of the vehicle would be determined in GEM 
through the proposed drive cycles. The agencies are proposing that the 
manufacturer would determine a truck's Cd, a dimensionless measure of a 
vehicle's aerodynamics, for input into the model through a combination 
of vehicle testing and vehicle design characteristics. Quantifying 
truck aerodynamics as an input to the GEM presents technical challenges 
because of the proliferation of truck configurations, the lack of a 
clearly preferable standardized test method, and subtle variations in 
measured Cd values among various test procedures. Class 7 and 8 tractor 
aerodynamics are currently developed by manufacturers using a range of 
techniques, including vehicle coastdown testing, wind tunnel testing, 
computational fluid dynamics, and constant speed tests as further 
discussed below. Reflecting that each of these approaches has 
limitations and no one approach appears to be superior to others, the 
agencies are proposing to allow all three aerodynamic evaluation 
methods to be used in demonstrating a vehicle's aerodynamic 
performance. The agencies welcome comments on each of these methods.
    The agencies are proposing that the coefficient of drag assessment 
be a product of test data and vehicle characteristics using good 
engineering judgment. The primary tool the agencies expect to use in 
our own evaluation of aerodynamic performance is the coastdown 
procedure described in SAE Recommended Practice J2263. 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)). The agencies anticipate that as we and the industry gain 
experience with assessing aerodynamic performance of HD vehicles for 
purposes of compliance a test-only approach may have advantages.
    We believe this broad approach allowing manufacturers to use 
multiple different test procedures to demonstrate aerodynamic 
performance is appropriate given that no single test procedure is 
superior in all aspects to other approaches. However, we also recognize 
the need for consistency and a level playing field in evaluating 
aerodynamic performance. To accomplish this, the agencies propose to 
use a two-part approach that evaluates aerodynamic performance not only 
through testing but through the application of good engineering 
judgment and a technical description of the vehicles aerodynamic 
characteristics. The first part of the proposed evaluation approach 
uses a bin structure characterizing the expected aerodynamic 
performance of tractors based on definable vehicle attributes. This bin 
approach is described further below. The second proposed evaluation 
element uses aerodynamic testing to measure the vehicle's aerodynamic 
performance under standardized conditions. The agencies expect that the 
SAE J2263 coastdown procedures will be the primary aerodynamic testing 
tool but are interested in working with the regulated industry and 
other interested stakeholders to develop a primary test approach. 
Additionally, the agencies propose to have a process that would allow 
manufacturers to demonstrate that another aerodynamic test procedure 
should also be allowed for purposes of generating inputs used in 
assessing a truck's performance. We are requesting comment on methods 
that should form the primary aerodynamic testing tool, methods that may 
be appropriate as alternatives, and the mechanism (including standards, 
practices, and unique criteria) for the agencies to consider allowing 
alternative aerodynamic test methods.
    NHTSA and EPA are proposing that manufacturers use a two part 
screening approach for determining the aerodynamic inputs to the GEM. 
The first part would require the manufacturers to assign each vehicle 
aerodynamic configuration to one of five aerodynamics bins created by 
EPA and NHTSA as described below. The assignment by bin reflects the 
aerodynamic characteristics of the vehicle. For each bin, EPA and NHTSA 
have already defined a nominal Cd that will be used in the GEM and a 
range of Cd values that would be expected from testing of vehicles 
meeting this bin description. The second part would require the 
manufacturer to then compare its own test results of aerodynamic 
performance (as conducted in accordance with the agencies' 
requirements) for the vehicle to confirm the actual aerodynamic 
performance was consistent with the agencies' expectations for vehicles 
within this

[[Page 74182]]

bin. If the predicted performance and actual observed performance 
match, the Cd value as an input for the GEM is the nominal Cd value 
defined for the bin. If, however, a manufacturer's test data 
demonstrates performance that is better than projected for the assigned 
bin a manufacturer may use the test data and good engineering judgment 
to demonstrate to the agencies that this particular vehicle's 
performance is in keeping with the performance level of a more 
aerodynamic bin and with the agencies' permission may use the Cd value 
of the more aerodynamic bin. Conversely, if the test data demonstrates 
that the performance is worse than the projected bin, then the 
manufacturer would use the Cd value from the less aerodynamic bin. 
Using this approach, the bin structure can be seen as the agencies' 
first effort to create a common measure of aerodynamic performance to 
benchmark the various test methods manufacturers may use to demonstrate 
aerodynamic performance. For example, if a manufacturer's test methods 
consistently produce Cd values that are better than projected by the 
agencies, EPA and NHTSA can use this information to further scrutinize 
the manufacturer's test procedure, helping to ensure that all 
manufacturers are competing on a level playing field.
    The agencies are proposing aerodynamic technology bins which divide 
the wide spectrum of tractor aerodynamics into five bins (i.e., 
categories). The first category, ``Classic,'' represents tractor bodies 
which prioritize appearance or special duty capabilities over 
aerodynamics. The Classic 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 category for aerodynamics is the ``Conventional'' 
tractor body. The agencies consider Conventional tractors to be the 
average new tractor today which capitalizes on a generally aerodynamic 
shape and avoids classic features which increase drag. Tractors within 
the ``SmartWay'' category build on Conventional tractors with added 
components to reduce drag in the most significant areas on the tractor, 
such as fully enclosed roof fairings, side extending gap reducers, fuel 
tank fairings, and streamlined grill/hood/mirrors/bumpers. The 
``Advanced SmartWay'' aerodynamic category builds upon the SmartWay 
tractor body with additional aerodynamic treatments such as underbody 
airflow treatment, down exhaust, and lowered ride height, among other 
technologies. And finally, ``Advanced SmartWay II'' 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 recognize that these proposed aerodynamic bins 
are static and referential and that there may be other technologies 
that may provide similar aerodynamic benefit. In addition, it is 
expected that aerodynamic equipment will advance over time and the 
agencies may find it appropriate and necessary to revise the bin 
descriptions.
    Under this proposal, the manufacturer would then input into GEM the 
Cd value specified for each bin as also defined in Table II-4. For 
example, if a manufacturer tests a Class 8 sleeper cab high roof 
tractor with features which are similar to a SmartWay tractor and the 
test produces a Cd value of 0.59, then the manufacturer would assign 
this tractor to the Class 8 Sleeper Cab High Roof SmartWay bin. The 
manufacturer would then use the Cd value of 0.60 as the input to GEM.
[GRAPHIC] [TIFF OMITTED] TP30NO10.015


[[Page 74183]]


    Coefficient of drag and frontal area of the tractor-trailer 
combination go hand-in-hand to determine the force required to overcome 
aerodynamic drag. As explained above, the agencies are proposing that 
the Cd value is one of the GEM inputs which will be derived by the 
manufacturer. However, the agencies are proposing to specify the 
truck's frontal area for each regulatory category (i.e., each of the 
seven subcategories which are proposed and listed in Table II-4 under 
the Aerodynamic Input to GEM). The frontal area of a high roof tractor 
pulling a box trailer will be determined primarily by the box trailer's 
dimensions and the ground clearance of the tractor. The frontal area of 
low and mid roof tractors will be determined by the tractor itself. An 
alternate approach to the proposed frontal area specification is to 
create the aerodynamic input table (as shown in Table II-4) with values 
that represent the Cd multiplied by the frontal area. This approach 
will provide the same aerodynamic load, but it will not allow the 
comparison of aerodynamic efficiency across regulatory categories that 
can be done with the Cd values alone. The agencies are interested in 
comments regarding the frontal area of trucks, specifically whether the 
specified frontal areas are appropriate and whether the use of standard 
frontal areas may have unanticipated consequences.
    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,\44\ the wind average drag coefficient is 
about 15 percent higher than the zero degree coefficient of drag. The 
agencies considered proposing the use of a wind averaged drag 
coefficient in this regulatory program, but ultimately decided to 
propose using coefficient of 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 
wind tunnels are currently the only tool to accurately assess the 
influence of wind speed and direction on a truck'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 technology effectiveness or change the 
kinds of technology decisions made by the tractor manufacturers in 
developing equipment to meet our proposed standards. However, the 
agencies are interested in receiving comment on approaches to develop 
wind averaged coefficient of drag values using computational fluid 
dynamics, coastdown, and constant speed test procedures.
---------------------------------------------------------------------------

    \44\ See 2010 NAS Report, Note 19, Finding 2-4 on page 39.
---------------------------------------------------------------------------

    The methodologies the agencies are considering for aerodynamic 
assessment include coastdown testing, wind tunnel testing, 
computational fluid dynamics, and constant speed testing. The agencies 
welcome information on a constant speed test procedure and how it could 
be applied to determine aerodynamic drag. In addition, the agencies 
seek comment on allowing multiple aerodynamic assessment methodologies 
and the need for comparison of aerodynamic assessment methods to 
determine method precision and accuracy.
(i) Coastdown Testing
    The coastdown test procedure has been used extensively in the 
light-duty industry to capture the road load force by coasting a 
vehicle along a flat straightaway under a set of prescribed conditions. 
Coast down testing has been used less extensively to obtain road load 
forces for medium- and heavy-duty vehicles. EPA has conducted a 
significant amount of test work to demonstrate that coastdown testing 
per SAE J2263 produces reasonably repeatable test results for Class 7 
and 8 tractor/trailer pairings, as described in draft RIA Chapter 3. 
The agencies propose that a manufacturer which chooses this method 
would determine a tractor's Cd value through analysis of the road load 
force equation derived from SAE J2263 Revised 2008-12 test results, as 
proposed in 40 CFR 1066.210.
(ii) Wind Tunnel Testing
    A wind tunnel provides a stable environment yielding a more 
repeatable test than coastdown. This allows the manufacturer to run 
multiple baseline vehicle tests and explore configuration modifications 
for nearly the same effort (e.g., time and cost) as conducting the 
coastdown procedure. In addition, wind tunnels provide testers with the 
ability to yaw the vehicle at positive and negative angles relative to 
the original centerline of the vehicle to accurately capture the 
influence of non-uniform wind direction on the Cd (e.g., wind averaged 
Cd).
    The agencies propose to allow the use of existing wind tunnel 
procedures adopted by SAE International with some minor modifications 
as discussed in Section V of this proposal. The agencies seek comments 
on the appropriateness of using the existing SAE wind tunnel 
procedures, and the modifications to these procedures, for this 
regulatory purpose.
(iii) Computational Fluid Dynamics
    Computational fluid dynamics, or CFD, capitalizes on today's 
computing power by modeling a full size vehicle and simulating the 
flows around this model to examine the fluid dynamic properties, in a 
virtual environment. CFD tools are used to solve either the Navier-
Stokes equations that relate the physical law of conservation of 
momentum to the flow relationship around a body in motion or a static 
body with fluid in motion around it, or the Boltzman equation that 
examines fluid mechanics and determines the characteristics of 
discreet, individual particles within a fluid and relates this behavior 
to the overall dynamics and behavior of the fluid. CFD analysis 
involves several steps: Defining the model structure or geometry based 
on provided specifications to define the basic model shape; applying a 
closed surface around the structure to define the external model shape 
(wrapping or surface meshing); dividing the control volume, including 
the model and the surrounding environment, up into smaller, discreet 
shapes (gridding); defining the flow conditions in and out of the 
control volume and the flow relationships within the grid (including 
eddies and turbulence); and solving the flow equations based on the 
prescribed flow conditions and relationships.
    This approach can be beneficial to manufacturers since they can 
rapidly prototype (e.g., design, research, and model) an entire vehicle 
without investing in material costs; they can modify and investigate 
changes easily; and the data files can be re-used and shared within the 
company or with corporate partners.
    The accuracy of the outputs from CFD analysis is highly dependent 
on the inputs. The CFD modeler decides what method to use for wrapping, 
how fine the mesh cell and grid size should be, and the physical and 
flow relationships within the environment. A balance must be achieved 
between the number of cells, which defines how fine the mesh is, and 
the computational times for a result (i.e., solution-time-efficiency). 
All of these decisions affect the results of the CFD aerodynamic 
assessment.

[[Page 74184]]

    Because CFD modeling is dependent on the quality of the data input 
and the design of the model, the agencies propose and seek comment on a 
minimum set of criteria applicable to using CFD for aerodynamic 
assessment in Section V.
(d) Tire Rolling Resistance Assessment
    NHTSA and EPA are proposing 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.\45\ 
The agencies believe the ISO test procedure is appropriate to propose 
for this program because the procedure is the same one used by NHTSA in 
its fuel efficiency tire labeling program \46\ and is consistent with 
the direction being taken by 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 vehicle. The results would be expressed as a rolling 
resistance coefficient and measured as kilogram per metric ton (kg/
metric ton). The agencies are proposing 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 would use a 
combined tire rolling resistance, where 15 percent of the gross weight 
of the truck and trailer would be distributed to the steer axle, 42.5 
percent to the drive axles, and 42.5 percent to the trailer axles.\47\ 
The trailer tires' rolling resistance would be 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.\48\
---------------------------------------------------------------------------

    \45\ 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.
    \46\ 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).
    \47\ 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).
    \48\ 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.
---------------------------------------------------------------------------

    We acknowledge that the useful life of original equipment tires 
used on tractors is shorter than the tractor's useful life. In this 
proposal, we are treating the tires as if the owner replaces the tire 
with tires that match the original equipment. Some owners opt for the 
original tires under the assumption that this is the best product. 
However, tractor tires are often retreaded or replaced. Steer tires on 
a highway tractor might need replacement after 75,000 to 150,000 miles. 
Drive tires might need retreading or replacement after 150,000 to 
300,000 miles. Of course, tire removal miles can be much higher or 
lower, depending upon a number of factors that affect tire removal 
miles. These include the original tread depth; desired tread depth at 
removal to maintain casing integrity; tire material and construction; 
typical load; tire ``scrub'' due to urban driving and set back axles; 
and, tire under-inflation. Since it is common for both medium- and 
heavy-duty truck tires to be replaced and retreaded, we welcome 
comments in this area. We are specifically seeking data for the rolling 
resistance of retread and replacement heavy-duty tires and the typical 
useful life of tractor tires.
(e) Weight Reduction Assessment
    EPA and NHTSA are seeking to account for the emissions and fuel 
consumption benefits of weight reduction as a control technology in 
heavy-duty trucks. Weight reduction impacts the emissions and fuel 
consumption performance of tractors in different ways depending on the 
truck's operation. For trucks that cube-out, the weight reduction will 
show a small reduction in grams of CO2 emitted or fuel 
consumed per mile travelled. The benefit is small because the weight 
reduction is minor compared to the overall weight of the combination 
tractor and payload. However, a weight reduction in tractors which 
operate at maximum gross vehicle weight rating would result in an 
increase in payload capacity. Increased vehicle payload without 
increased GVWR significantly reduces fuel consumption and 
CO2 emissions per ton mile of freight delivered. It also 
leads to fewer vehicle miles driven with a proportional reduction in 
traffic accidents.
    The empty curb weight of tractors varies significantly today. Items 
as common as fuel tanks can vary between 50 and 300 gallons each for a 
given truck model. Information provided by truck manufacturers 
indicates that there may be as much as a 5,000 to 17,000 pound 
difference in curb weight between the lightest and heaviest tractors 
within a regulatory subcategory (such as Class 8 sleeper cab with a 
high roof). Because there is such a large variation in the baseline 
weight among trucks that perform roughly similar functions with roughly 
similar configurations, there is not an effective way to quantify the 
exact CO2 and fuel consumption benefit of mass reduction 
using GEM because of the difficulty in establishing a baseline. 
However, if the weight reduction is limited to tires and wheels, then 
both the baseline and weight differentials for these are readily 
quantifiable and well-understood. Therefore, the agencies are proposing 
that the mass reduction that would be simulated be limited only to 
reductions in wheel and tire weight. In the context of this heavy-duty 
vehicle program with only changes to tires and wheels, the agencies do 
not foresee any related impact on safety.\49\ The agencies welcome 
comments regarding this approach and detailed data to further improve 
the robustness of the agencies' assumed baseline truck tare/curb 
weights for each regulatory category used within the model, as outlined 
in draft RIA Chapter 3.5.
---------------------------------------------------------------------------

    \49\ For more information on the estimated safety effects of 
this proposed rule, see Chapter 9 of the draft RIA.
---------------------------------------------------------------------------

    EPA and NHTSA are proposing to specify the baseline vehicle weight 
for each regulatory category (including the tires and wheels), but 
allow manufacturers to quantify weight reductions based on the wheel 
material selection and single wide versus dual tires per Table II-5. 
The agencies assume the baseline wheel and tire configuration contains 
dual tires with steel wheels because these represent the vast majority 
of new vehicle configurations today. The proposed weight reduction due 
to the wheels and tires would be reflected in the payload tons by 
increasing the specified payload by the weight reduction amount 
discounted by two thirds to recognize that approximately one third of 
the truck miles are travelled at maximum payload, as discussed below in 
the payload discussion.

[[Page 74185]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.016

(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.\50\ 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 truck cab itself than to pull off the road and find 
accommodations. During this rest period a driver will idle the truck in 
order to provide heating or cooling or run on-board appliances. In some 
cases the engine can idle in excess of 10 hours. During this period, 
the truck will consume approximately 0.8 gallons of fuel and emit over 
8,000 grams of CO2 per hour. An average truck can consume 8 
gallons of fuel and emit over 80,000 grams of CO2 during 
overnight idling in such a case.
---------------------------------------------------------------------------

    \50\ 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/.
---------------------------------------------------------------------------

    Idling reduction technologies 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 
available today. The agencies are proposing to include extended idle 
reduction technology as an input to the GEM for Class 8 sleeper cabs. 
The manufacturer would input the value based on the idle reduction 
technology installed on the truck. As discussed further in Section III, 
if a manufacturer chooses to use idle reduction technology to meet the 
standard, then it would require an automatic main engine shutoff after 
5 minutes to help ensure the idle reductions are realized in-use. 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 proposed 
standards. The proposed value (5 g CO2/ton-mile or 0.5 gal/
1,000 ton-mile) for the idle reduction technologies was determined 
using an assumption of 1,800 idling hours per year, 125,000 miles 
travelled, and a baseline idle fuel consumption of 0.8 gallons per 
hour. Additional detail on the emission and fuel consumption reduction 
values are included in draft RIA Chapter 2.
(g) Vehicle Speed Limiters
    Fuel consumption and CO2 emissions increase proportional 
to the square of vehicle speed.\51\ 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. The feature is electronically 
programmed and controlled. Manufacturers today sell trucks with vehicle 
speed limiters and allow the customers to set the limit. However, as 
proposed the GEM will not provide a fuel consumption reduction for a 
limiter that can be overridden. In order to obtain a benefit for the 
program, the 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. As with other engine calibration aspects of emission 
controls, tampering with a calibration would be considered unlawful by 
EPA. If the manufacturer installs a vehicle speed limiter into a truck 
that is not easily overridden, then the manufacturer would input the 
vehicle speed limit setpoint into GEM.
---------------------------------------------------------------------------

    \51\ See 2010 NAS Report, Note 19, Page 28. Road Load Force 
Equation defines the aerodynamic portion of the road load as \1/2\ * 
Coefficient of Drag * Frontal Area * air density * vehicle speed 
squared.
---------------------------------------------------------------------------

(h) Defined Vehicle Configurations in the GEM
    As discussed above, the agencies are proposing methodologies that 
manufacturers would use to quantify the values to be input into the GEM 
for these factors affecting truck efficiency: Coefficient of Drag, Tire 
Rolling Resistance Coefficient, Weight Reduction, Vehicle Speed 
Limiter, and Extended Idle Reduction Technology. The other aspects of 
vehicle performance are fixed within the model and are not varied for 
the purpose of compliance. The defined inputs being proposed include 
the drive cycle, tractor-trailer combination curb weight, payload, 
engine characteristics, and drivetrain for each vehicle type, and 
others. We are seeking comments accompanied with data on the defined 
model inputs as described in draft RIA Chapter 4.
(i) Vehicle Drive Cycles
    As noted by the 2010 NAS Report,\52\ 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. If the 
agencies propose an ill-suited drive cycle for a regulatory category, 
it may 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

[[Page 74186]]

delivery may spend little time on the highway, reducing the benefits 
that would be 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.\53\ 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 truck has a different drive 
cycle in-use.
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    \52\ See 2010 NAS Report, Note 19, Chapters 4 and 8.
    \53\ This situation does not typically occur for heavy-duty 
emission control technology designed to control criteria pollutants 
such as PM and NOX.
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    The agencies are proposing a modified version of the California ARB 
Heavy Heavy-duty Truck 5 Mode Cycle,\54\ 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.\55\ 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 truck application usage patterns. EPA analyzed the five cycles 
and found that some modifications to the modes appear to be needed to 
allow sufficient flexibility in weightings. The agencies are proposing 
the use of the Transient mode, as defined by California ARB, because it 
broadly covers urban driving. The agencies are also proposing altered 
versions of the High Speed Cruise and Low Speed Cruise modes which 
would reflect only constant speed cycles at 65 mph and 55 mph 
respectively. EPA and NHTSA relied on the EPA MOVES analysis of Federal 
Highway Administration data to develop the proposed mode weightings to 
characterize typical operations of heavy-duty trucks, per Table II-6 
below.\56\ A detailed discussion of drive cycles is included in draft 
RIA Chapter 3.\57\
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    \54\ 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.
    \55\ EPA's MOVES (Motor Vehicle Emission Simulator). See http://www.epa.gov/otaq/models/moves/index.htm for additional information.
    \56\ 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.
    \57\ 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''.
[GRAPHIC] [TIFF OMITTED] TP30NO10.017

(ii) 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 truck is important because it in part determines the 
impact of technologies, such as rolling resistance, on GHG emissions 
and fuel consumption. The agencies are proposing to specify each of 
these aspects of the vehicle.
    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.\58\ Details of the individual weight inputs by 
regulatory category are included in draft RIA Chapter 3.
---------------------------------------------------------------------------

    \58\ 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.
---------------------------------------------------------------------------

    There are several methods that the agencies have considered for 
evaluating the GHG emissions and fuel consumption of tractors used to 
carry freight. A key factor in these methods is the weight of the truck 
that is assumed for purposes of the evaluation. 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 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).\59\
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    \59\ 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) of the vehicle. For example, a 
typical Class 7 tractor can carry less payload than a Class 8 tractor. 
The Federal Highway Administration developed Truck Payload Equivalent 
Factors to inform the development of highway system strategies using 
Vehicle Inventory and Use Survey (VIUS) and Vehicle Travel Information 
System data. Their results

[[Page 74187]]

found that the average payload of a Class 8 truck ranged from 36,247 to 
40,089 pounds, depending on the average distance travelled per day.\60\ 
The same results found that Class 7 trucks carried between 18,674 and 
34,210 pounds of payload also depending on average distance travelled 
per day. Based on this data, the agencies are proposing 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 
are proposing a common payload for Class 8 day cabs and sleeper cabs 
because the data available does 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.'' Additional details on proposed 
payloads are included in draft RIA Chapter 3.
---------------------------------------------------------------------------

    \60\ 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.
---------------------------------------------------------------------------

(iii) Standardized Trailers
    NHTSA and EPA are proposing that the tractor performance in the GEM 
would be judged by assuming it is pulling a standardized trailer. The 
agencies believe that an assessment of the tractor aerodynamics should 
be conducted using a tractor-trailer combination to reflect the impact 
of aerodynamic technologies in actual use, where tractors are designed 
and used with a trailer. Assessing the tractor aerodynamics using only 
the tractor would not be a reasonable way to assess in-use impacts. For 
example, the in-use aerodynamic drag while pulling a trailer is 
different than without the trailer and the full impact of an 
aerodynamic technology on reducing emissions and fuel consumption would 
not be reflected if the assessment is performed on a tractor without a 
trailer.
    In addition to assessing the tractor with a trailer, it is 
appropriate to adopt a standardized trailer used for testing, and to 
vary the standardized trailer by the regulatory category. This is 
similar to the standardization of payload discussed above, as a way to 
reasonably reflect in-use operating conditions. High roof tractors are 
optimally designed to pull box trailers. The roof fairing on a tractor 
is the feature designed to minimize the height differential between the 
tractor and typical trailer to reduce the air flow disruption. Low roof 
tractors are designed to carry flat bed or low-boy trailers. Mid roof 
tractors are designed to carry tanker and bulk carrier trailers. The 
agencies conducted a survey of tractor-trailer pairing in-use to 
evaluate the representativeness of this premise. The survey of over 
3,000 tractor-trailer combinations found that in 95 percent of the 
combination tractors the tractor's roof height was paired appropriately 
for the type of trailer that it was pulling.\61\ The agencies also have 
evaluated the impact of pairing a low roof tractor with a box trailer 
in coastdown testing and found that the aerodynamic force increases by 
20 percent over a high roof tractor pulling the same box trailer.\62\ 
Therefore, drivers have a large incentive to use the appropriate 
matching to reduce their fuel costs. However, the agencies recognize 
that in operation tractors sometimes pull trailers other than the type 
that it was designed to carry. The agencies are proposing the matching 
of trailers to roof height for the test procedure. To do otherwise 
would necessarily result in a standard reflecting substandard 
aerodynamic performance, and thereby result in standards which are less 
stringent than would be appropriate based on the reasonable assumption 
that tractors will generally pair with trailer of appropriate roof 
height. The other aspects of the test procedure such as empty trailer 
weight, location of payload, and tractor-trailer gap are being proposed 
for each regulatory category to provide consistent test procedures.
---------------------------------------------------------------------------

    \61\ U.S. EPA. Truck and Trailer Roof Height Match Analysis 
Memorandum from Amy Kopin to the Docket, August 9, 2010. Docket 
Identification Number EPA-HQ-OAR-2010-0162-0045.
    \62\ See the draft RIA Chapter 2 for additional detail.
---------------------------------------------------------------------------

(iv) Standardized Drivetrain
    The agencies' assessment of the current vehicle configuration 
process at the truck dealer's level is 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 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 proposing 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 GEM
    As the agencies are proposing separate engine and tractor 
standards, the GEM will be used to assess the compliance of the tractor 
with the tractor standard. To maintain the separate assessments, the 
agencies are proposing to define 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 tractor that uses an 
engine with emissions and fuel consumption better than the standards 
would require fewer vehicle reductions than those technically feasible 
reductions being proposed. The agencies are proposing two distinct fuel 
consumption maps for use in GEM. EPA proposes the first fuel 
consumption map would be used in GEM for the 2014 through 2016 model 
years and represents an average engine which meets the 2014 model year 
engine CO2 emissions standards being proposed. NHTSA 
proposes to use the same fuel map for its 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 would be used beginning in 
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 proposed MY 2017 standard. 
Effectively there is no change in stringency of the tractor vehicle 
(not including the engine) and there is stability in the tractor 
vehicle (not including engine) standards for the full rulemaking 
period.\63\ These inputs are appropriate given the separate proposed 
regulatory requirement that Class 7 and 8 combination tractor 
manufacturers use only certified engines.
---------------------------------------------------------------------------

    \63\ As noted earlier, use of the 2017 model year fuel 
consumption map as a GEM input results in numerically more stringent 
proposed vehicle standards for MY 2017.
---------------------------------------------------------------------------

(i) Engine Test Procedure
    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.\64\ An analogous metric for 
engines would be the amount of fuel consumed per unit of work. Thus, 
EPA is proposing that GHG emission standards for engines under the CAA 
would be expressed as g/bhp-

[[Page 74188]]

hr; NHTSA's proposed fuel consumption standards under EISA, in turn, 
would be represented as gal/100 bhp-hr. This metric is also consistent 
with EPA's current standards for non-GHG emissions for these engines.
---------------------------------------------------------------------------

    \64\ See NAS Report, Note 19, at page 39.
---------------------------------------------------------------------------

    EPA's criteria pollutant standards for engines require that 
manufacturers demonstrate compliance over the transient Heavy-duty FTP 
test cycle; the steady-state SET test cycle; and the not-to-exceed test 
(NTE test). 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. With regard to GHG and fuel consumption control, 
the agencies believe it is more 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. For engines used primarily in 
line-haul combination tractor trailer operations, we believe the 
steady-state SET procedure more appropriately reflects in-use engine 
operation. By setting standards based on the most representative test 
cycle, we can have confidence that engine manufacturers will design 
engines for the best GHG and fuel consumption performance relative to 
the most common type of expected engine operation. There is no 
incentive to design the engines to give worse fuel consumption under 
other types of operation, relative to the most common type of 
operation, and we are not concerned if manufacturers further calibrate 
these designs to give better in-use fuel consumption during other 
operation, while maintaining compliance with the criteria emissions 
standards as such calibration is entirely consistent with the goals of 
our joint program.
    Further, we are concerned that setting standards based on both 
transient and steady-state operating conditions for all engines could 
lead to undesirable outcomes. For example, turbocompounding is one 
technology that the agencies have identified as a likely approach for 
compliance against our proposed HHD SET standard described below. 
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 only for engines intended for use 
in combination tractor trailers could lead manufacturers to not apply 
turbocompounding because the full benefits are not demonstrated on the 
Heavy-duty FTP even though it can be a highly cost-effective means to 
reduce GHG emissions and lower fuel consumption in more steady state 
applications.
    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 are proposing to exclude the CO2 
emissions and fuel consumption increases due to regeneration from the 
calculation of the compliance levels over the defined test procedures. 
We considered including regeneration in the estimate of fuel 
consumption and GHG emissions and have 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 timeframe of this proposal. 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. We are seeking 
comments regarding regeneration emissions and what approach if any the 
agencies should use in reflecting regeneration emissions in this 
program.
    In conclusion, for Class 7 and 8 tractors, compliance with the 
vehicle standard would be determined by establishing values for the 
variable inputs and using the prescribed inputs in GEM and compliance 
against the engine standard using the SET engine cycle. The model would 
produce CO2 and fuel consumption results that would be 
compared against EPA's and NHTSA's respective standards.
(j) Chassis-Based Test Procedure
    The agencies also 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.\65\
---------------------------------------------------------------------------

    \65\ 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 truck 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

[[Page 74189]]

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 was adopted 
based on a chassis test procedure.
    Although the agencies are not proposing the use of a complete 
chassis based test procedure for Class 7 and 8 tractors, we believe 
such an approach could 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. We request 
comments on the potential use of chassis based test procedures in the 
future to augment or replace the model based approach we are proposing.
(3) Summary of Proposed Flexibility and Credit Provisions
    EPA and NHTSA are proposing 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.
    The agencies are proposing that credits earned by manufacturers 
under this ABT program be restricted for use to only within the same 
regulatory subcategory for two reasons. First, relating credits between 
categories is tenuous because of the differences in regulatory useful 
lives. We want to avoid having credits from longer useful life 
categories flooding shorter useful life categories, adversely impacting 
compliance with CO2 or fuel consumption standards in the 
shorter useful life category, and we have not based the level of the 
standard on such impact on compliance. In addition, extending the use 
of credits beyond these designated categories could inadvertently have 
major impacts on the competitive market place, and we want to avoid 
such results. For example, a manufacturer which has multiple engine 
offerings over several regulatory categories could mix credits across 
engine categories and shift the burden between them, possibly impacting 
the competitive market place. Similarly, integrated manufacturers which 
produce both engines and trucks could shift credits between engines and 
trucks and have a similar effect. We would like to ensure that this 
proposal reduces the CO2 emissions and fuel consumption but 
does not inadvertently have such impacts on the market place. However, 
we welcome comments on the extension of credits beyond the limitations 
we are proposing.
    The agencies are also proposing to provide provisions to 
manufacturers for early credits, the use of advanced technologies and 
innovative technologies which are described in greater detail in 
Section IV.
(4) Deferral of Standards for Tractor and Engine Manufacturing 
Companies That Are Small Businesses
    EPA and NHTSA are proposing to defer 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.\66\ 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 or engine 
manufacturers.
---------------------------------------------------------------------------

    \66\ See Sec.  1036.150 and Sec.  1037.150.
---------------------------------------------------------------------------

    The agencies have identified two entities that fit the SBA size 
criterion of a small business.\67\ 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,\68\ and therefore that the exemption will 
have a negligible impact on the GHG emissions and fuel consumption 
improvements from the proposed standards.
---------------------------------------------------------------------------

    \67\ The agencies have identified Ottawa Truck, Inc. and Kalmar 
Industries USA as two potential small tractor manufacturers.
    \68\ M.J. Bradley. Heavy-duty Vehicle Market Analysis. May 2009.
---------------------------------------------------------------------------

    To ensure that the agencies are aware of which companies would be 
exempt, we propose 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.

C. Heavy-Duty Pickup Trucks and Vans

    The primary elements of the EPA and NHTSA programs being proposed 
for complete HD pickups and vans are presented in this section. These 
provisions also cover incomplete HD pickups and vans that are sold by 
vehicle manufacturers as cab-chassis (chassis-cab, box-delete, bed-
delete, cut-away van) vehicles, as discussed in detail in Section 
V.B(1)(e). Section II.C(1) explains the proposed form of the 
CO2 and fuel consumption standards, the proposed numerical 
levels for those standards, and the proposed approach to phasing in the 
standards over time. The proposed measurement procedure for determining 
compliance is discussed in Section II.C(2), and the proposed EPA and 
NHTSA compliance programs are discussed in Section II.C(3). Sections 
II.C(4) discusses proposed implementation flexibility provisions. 
Section II.E discusses additional standards and provisions for 
N2O and CH4 emissions, for impacts from vehicle 
air conditioning, and for ethanol-fueled and electric vehicles.
(1) What Are the Proposed 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 vehicle 
manufacturers as complete vehicles, ready for use on the road. In 
addition, most of these 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.\69\ As a 
result, Class 2b and 3 complete vehicles share much more in common with 
light-duty trucks than with other heavy-duty vehicles.
---------------------------------------------------------------------------

    \69\ As discussed briefly in Section I and in more detail in 
Section V, this regulatory category also covers some incomplete 
Class 2b/3 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

[[Page 74190]]

brakes), 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 proposed 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.''
(b) Weight-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 proposal, 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. Weight-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 weight-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.\70\
---------------------------------------------------------------------------

    \70\ Section II.C(2) discusses our decision to propose 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 combined 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, 2009). The 
agencies believe that using payload and towing capacities as the 
weight-based attributes would avoid 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 have 
decided to propose standards for HD pickups and vans based on a ``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 would account for the 
fact that 4wd, critical to enabling the many off-road heavy-duty work 
applications, adds roughly 500 lb to the vehicle weight. Under our 
proposal, target GHG and fuel consumption standards would be determined 
for each vehicle with a unique work factor. These targets would then be 
production weighted and summed to derive a manufacturer's annual fleet 
average standards.
    To ensure consistency and help preclude gaming, we are proposing 
that payload capacity be defined as GVWR minus curb weight, and towing 
capacity as GCWR minus GVWR. We are proposing that, for purposes of 
determining the work factor, GCWR be defined according to SAE 
Recommended Practice J2807 APR2008, GVWR be defined consistent with 
EPA's criteria pollutants program, and curb weight be defined as in 40 
CFR

[[Page 74191]]

86.1803-01. We request comment on the need to establish additional 
regulations or guidance to ensure that these terms are determined and 
applied consistently across the HD pickup and van industry for the 
purpose of determining standards.
    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.\71\ We 
request comment on this proposed approach.
---------------------------------------------------------------------------

    \71\ 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 proposed 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 
truck 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 proposal 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.
    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 would be affected by 
the standard. With the proposed 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) Proposed Standards
    The agencies are proposing standards based on a technology analysis 
performed by EPA to determine the appropriate HD pickup and van 
standards. This analysis, described in detail in draft 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 proposing the CO2 
attribute-based target standards shown in Figure II-1 and II-2, and 
NHTSA is proposing the equivalent attribute-based fuel consumption 
target standards, also shown in Figure II-1 and II-2, 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 statutory obligations. Also, for 
reasons discussed below, separate targets are being established for 
gasoline-fueled (and any other Otto-cycle) vehicles and diesel-fueled 
(and any other Diesel-cycle) vehicles. The targets would be used to 
determine the production-weighted standards that apply to the combined 
diesel and gasoline fleet of HD pickups and vans produced by a 
manufacturer in each model year.

[[Page 74192]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.018

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

    \72\ The NHTSA proposal 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 74193]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.019

    Described \73\ mathematically, EPA's and NHTSA's proposed functions 
are defined by the following formulae:

    \73\ The NHTSA proposal 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-7 or Table II-
8.\74\
---------------------------------------------------------------------------

    \74\ The NHTSA proposal 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 74194]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.020

[GRAPHIC] [TIFF OMITTED] TP30NO10.021

    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. Much of the information used to make this technology 
assessment was developed for the recent 2012-2016 MY light-duty vehicle 
rule. 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 proposing 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) vehicles. An additional two percent reduction in GHGs would be 
achieved by the EPA program from a proposed direct air conditioning 
leakage standard. 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

[[Page 74195]]

levels for gasoline and diesel vehicles, which is important in ensuring 
our proposed program maintains product choices available to vehicle 
buyers.
    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 
would generally be equivalent to fuel consumption. However, as 
explained below in Section II. E. (3), EPA is proposing an alternative 
for manufacturers to demonstrate compliance with N2O and 
CH4 emissions standards through the calculation of a 
CO2-equivalent (CO2eq) emissions level that would 
be compared to the CO2-based standards, similar to the 
recently promulgated light-duty GHG standards for model years 2012-
2016. For test families that do not use this compliance alternative, 
the measured performance values for CO2 and fuel consumption 
would be equivalent because the same test runs and measurement data 
would be used to determine both values, and calculated fuel consumption 
would be based on the same conversion factors that are used to 
establish the relationship between the CO2 and fuel 
consumption target curves (8887 g CO2/gallon for gasoline 
and 10,180 g CO2/gallon for diesel fuel). In this case, for 
example, if a manufacturer's fleet average measured compliance value 
exactly meets the fleet average CO2 standard, it will also 
exactly meet the fuel consumption standard. The proposed NHTSA fuel 
consumption program will not use a CO2eq metric. Measured 
performance to standards would be based on the measurement of 
CO2 with no adjustment for N2O and 
CH4. For manufacturers that choose to use the EPA 
CO2eq approach, compliance with the CO2 standard 
would not be directly equivalent to compliance with the NHTSA fuel 
consumption standard.
(d) Proposed Implementation Plan
(i) EPA Program Phase-In MY 2014-2018
    EPA is proposing 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 would need to meet a fleet-average standard that would become 
increasingly more stringent each year of the phase-in period. For both 
gasoline and diesel vehicles, this phase-in would be 15-20-40-60-100 
percent 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 would be 15% of the fully-phased-in reductions. Figures II-1 
and II-2, and Table II-7, reflect this phase-in approach.
    EPA is also proposing to provide manufacturers with an optional 
alternative implementation schedule in model years 2016 through 2018, 
equivalent to NHTSA's proposed first alternative for standards that do 
not change over these model years, described below. Under this option 
the phase-in would be 15-20-67-67-67-100 percent in model years 2014-
2015-2016-2017-2018-2019, respectively. Table II-8, above, provides the 
coefficients ``a'' and ``b'' for this manufacturer's alternative. 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 would 
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 in 2014. EPA also requests comment on a different 
regulatory approach to the phase-in, intended to reduce the testing and 
certification burden on manufacturers during the 2014-2017 phase-in 
years, while achieving GHG reductions on the same schedule as the 
proposed phase-in. In this alternative approach, each manufacturer 
would be required to demonstrate compliance with the final 2018 
targets, but only over a predefined percentage of its HD pickup and van 
production. The remaining vehicles produced each year would not be 
regulated for GHGs. Thus this approach would have the effect of setting 
final standards in 2014 that do not vary over time, but with an 
annually increasing set of regulated vehicles. The percentage of 
regulated vehicles would increase each year, to 100 percent in 2018. We 
think it likely that manufacturers would leave the highest emitting 
vehicles unregulated for as long as possible under this approach, 
because these vehicles would tend to be the costliest to redesign or 
may simply be phased out of production. We therefore expect that, to be 
equivalent, the percentage penetration each year would be higher than 
the 15-20-40-60 percent penetrations required under the proposed 
approach. EPA requests comment on this regulatory alternative, and on 
what percentage penetrations are appropriate to achieve equivalent 
program benefits.
(ii) NHTSA Program Phase-In 2016 and Later
    NHTSA is proposing to allow manufacturers to select one of two fuel 
consumption standard alternatives for model years 2016 and later. 
Manufacturers would select an alternative at the same time they submit 
the model year 2016 Pre-Certification Compliance Report; and, once 
selected, the alternative would apply for model years 2016 and later, 
and could not be reversed. To meet the EISA statutory requirement for 
three years of regulatory stability, the first alternative would define 
a fuel consumption target line function for gasoline vehicles and a 
target line function for diesel vehicles that would not change for 
model years 2016 and later. The proposed target line function 
coefficients are provided in Table II-8.
    The second alternative would be equivalent to the EPA target line 
functions in each model year starting in 2016 and continuing 
afterwards. Stringency of fuel consumption standards would increase 
gradually for the 2016 and later model years. Relative to a model year 
2010 unregulated baseline, for both gasoline and diesel vehicles, 
stringency would 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 2018 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

[[Page 74196]]

either alternative and have a similar credit balance at the end of 
model year 2018 under the EPA and NHTSA programs.
    NHTSA also requests comment on a different regulatory approach that 
would parallel the above-described EPA regulatory alternative involving 
certification of a pre-defined percentage of a manufacturer's HD pickup 
and van production.
(iii) NHTSA Voluntary Standards Period
    NHTSA is proposing 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 into the program, the program would become 
mandatory and the manufacturer would not be allowed to reverse this 
decision. To opt into the program, a manufacturer must declare its 
intent to opt in to the program at the same time it submits the Pre-
Certification Compliance Report. See proposed regulatory text for 49 
CFR 535.8 for information related to the Pre-Certification Compliance 
Report. If a manufacturer elects to opt into the program in 2014, the 
program would be mandatory for 2014 and 2015. 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 2018 target line function (under the 
NHTSA second alternative) in model years 2014-2015, respectively. The 
corresponding absolute standards targets levels are provided in Figure 
II-1 and II-2, and the accompanying equations.
    NHTSA also requests comment on a different regulatory approach that 
would parallel the above-described EPA regulatory alternative involving 
certification of a pre-defined percentage of a manufacturer's HD pickup 
and van production.
(2) What are the proposed HD pickup and van test cycles and procedures?
    EPA and NHTSA are proposing 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 would 
be identical to that of the light-duty test, other test parameters for 
running the HFET, such as test vehicle loaded weight, would be 
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 would 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 
proposed work factor-based CO2 and fuel consumption 
standards, since the data on the baseline and technology efficiency was 
also 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. 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 \1/2\ 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 \1/
2\ payload better fits their usage in the real world and would 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. We are therefore proposing to use ALVW for test vehicle 
loading in GHG and fuel consumption testing.
    EPA and NHTSA request comment on the proposed test cycles, 
weighting factors, test loading conditions, and other factors that are 
important for establishing an effective GHG and fuel consumption test 
program. Additional provisions for our proposed testing and compliance 
program are provided in Section V.B.
(3) How are the HD pickup and van standards structured?
    EPA and NHTSA are proposing fleet average standards for new HD 
pickups and vans, based on a manufacturer's new vehicle fleet makeup. 
In addition, EPA is proposing in-use standards that would apply to the 
individual vehicles in this fleet over their useful lives. The 
compliance provisions for these proposed 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 below 
and in greater detail in Section V.B. We request comment on any 
compliance provisions we have taken from the light-duty program that 
commenters feel would not be appropriate for HD pickups and vans or 
that should be adjusted in some way to better regulate HD GHGs and fuel 
consumption cost-effectively.
(a) Fleet Average Standards
    In this proposal we outline how each manufacturer would 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 would have 
individual targets at numerically higher CO2 and fuel 
consumption levels than lower payload/towing vehicles would, as 
discussed in Section II.C(1). The fleet average standard for a 
manufacturer would be 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 
would be based on its final production figures for the model year, and 
thus a final assessment of compliance would occur after production for 
the model year ended. Because compliance with the fleet average 
standards depends on

[[Page 74197]]

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 would 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 would issue a certificate for the vehicles covered by the 
test group based on this demonstration, and would 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 would 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 would 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 proposing 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 would be used. EPA and NHTSA 
anticipate that the deterioration factor would 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 proposing would apply to individual 
vehicles. NHTSA is not proposing to adopt in-use standards because it 
is not required under EISA, and because it is not currently anticipated 
that there will be any notable deterioration of fuel consumption. For 
the EPA proposal, 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 proposing 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 proposing 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 proposing 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 proposing an adjustment factor for the 
in-use standard to provide some margin for production and test-to-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 proposing 
that each model's in-use CO2 standard would 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).
    As it does now for heavy-duty vehicle criteria pollutants, EPA 
would use a variety of mechanisms to conduct assessments of compliance 
with the proposed in-use standards, including pre-production 
certification and in-use monitoring once vehicles enter customer 
service. The full useful life in-use standards would apply to vehicles 
that had entered customer service. The same standards would apply to 
vehicles used in pre-production and production line testing, except 
that deterioration factors would not be applied.
(4) What HD pickup and van flexibility provisions are being proposed?
    This proposal 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 
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 proposing 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 proposed approach, a 
manufacturer's HD pickup and van fleet that achieves a fleet average 
CO2 or fuel consumption level better than its standard would 
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 
would 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 2012-2016 MY light-duty vehicle National Program, 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 would 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 years, 
consistent with the light-duty program. We are proposing that, after 
satisfying any need to offset pre-existing deficits, a manufacturer may 
bank remaining credits for use in future years. We are also proposing 
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 proposing any credit transferability 
to or from other credit programs, such as the light-duty GHG and fuel 
consumption programs or the proposed heavy-duty engine ABT program.
    Consistent with the President's May 21, 2010 directive to promote 
advanced technology vehicles, we are proposing and seeking comment on 
flexibility provisions that would parallel similar provisions adopted 
in the light-duty program. These include credits for advance technology 
vehicles such as electric vehicles, and credits for

[[Page 74198]]

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.
    We believe that it may also be appropriate to take steps to 
recognize the benefits of flexible-fueled vehicles (FFVs) and dedicated 
alternative-fueled vehicles based on the approach taken by EPA in the 
light-duty vehicle rule for later models years (2016 and later). 
However, unlike in that rule, we do not believe it is appropriate to 
create a provision for additional credits similar to the 2012-2015 
light-duty program because the HD sector does not have the incentives 
mandated in EISA for light-duty vehicles. In fact, since heavy-duty 
vehicles were not included in the EISA incentives for FFVs, 
manufacturers have not in the past produced FFV heavy-duty vehicles. On 
the other hand, we do seek 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.\75\ As proposed, FFV performance would 
be determined in the same way as for light-duty vehicles, with a 50-50 
weighting of alternative and conventional fuel test results through MY 
2015, and a 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). For dedicated alternative fueled 
vehicles, NHTSA proposes that vehicles be tested with the alternative 
fuel, and a petroleum equivalent fuel consumption level be calculated 
based on the Petroleum Equivalency Factor (PEF) that is determined by 
the Department of Energy. However, we are accepting comment on whether 
to provide a flexibility program similar to the program we currently 
offer for light-duty FFV vehicles.
---------------------------------------------------------------------------

    \75\ E85 is a blended fuel consisting of nominally 15 percent 
gasoline and 85 percent ethanol.
---------------------------------------------------------------------------

D. Class 2b-8 Vocational Vehicles

    Class 2b-8 vocational vehicles consist of a very wide variety of 
configurations including delivery, refuse, utility, dump, cement, 
transit bus, shuttle bus, school bus, emergency vehicle, motor 
homes,\76\ and tow trucks, among others. The agencies are defining that 
Class 2b-8 vocational vehicles are all heavy-duty vehicles which are 
not included in the Heavy-duty Pickup Truck and Van or the Class 7 and 
8 Tractor categories, with the exception of vehicles for which the 
agencies are deferring setting of standards, such as small business 
manufacturers. In addition, recreational vehicles are included under 
EPA's proposed standards but are not included under NHTSA's proposed 
standards.
---------------------------------------------------------------------------

    \76\ See above for discussion of applicability of NHTSA's 
standards to non-commercial vehicles.
---------------------------------------------------------------------------

    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 agencies face difficulties in establishing the baseline 
CO2 and fuel consumption performance for the wide variety of 
vocational vehicles which makes it difficult to try and set different 
standards for a large number of potential regulatory categories. 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 
tires) will be the same between these two types of complete vehicles. 
Furthermore, the agencies evaluated the aerodynamic improvement 
opportunities for vocational vehicles. For example, the aerodynamics of 
a fire truck are impacted significantly by the equipment such as 
ladders located on the exterior of the truck. 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 no fuel consumption 
reduction opportunity through aerodynamic technologies for bucket 
trucks, transit buses, and refuse trucks \77\ 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 trucks which operate at higher speeds.\78\ 
To overcome the lack of baseline information from the different vehicle 
applications without sacrificing much fuel consumption or GHG emission 
reduction potential, the agencies propose to set standards for the 
chassis manufacturers of vocational vehicles (instead of the body 
builders) and the engine manufacturers.
---------------------------------------------------------------------------

    \77\ See 2010 NAS Report, Note 19, page 133.
    \78\ See 2010 NAS Report, Note 19, page 110.
---------------------------------------------------------------------------

    EPA is proposing CO2 standards and NHTSA is proposing 
fuel consumption standards for manufacturers of chassis for new 
vocational vehicles and for manufacturers of heavy-duty engines 
installed in these vehicles. The proposed heavy-duty engine standards 
for CO2 emissions and fuel consumption would focus on 
potential technological improvements in fuel combustion and overall 
engine efficiency and those proposed controls would achieve most of the 
emission reductions. Further reductions from the Class 2b-8 vocational 
vehicle itself are possible within the timeframe of these proposed 
regulations. Therefore, the agencies are also proposing 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 draft RIA Chapter 2, show that these 
proposed standards appear appropriate under each agency's respective 
statutory authorities. Together these standards are estimated to 
achieve reductions of up to 11 percent from vocational vehicles.
    EPA is also proposing standards to control N2O and 
CH4 emissions from Class 2b-8 vocational vehicles. The 
proposed heavy-duty engine standards for both N2O and 
CH4 and details of the standard are included in the 
discussion in Section II. EPA is not proposing air conditioning leakage 
standards applying to chassis manufacturers to address HFC emissions.
    As discussed further below, the agencies propose to set 
CO2 and fuel consumption standards for these 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 propose to aggregate several vehicle weight categories under a 
single category for setting the standards. The agencies propose to 
divide the vocational vehicle segment into three broad regulatory 
categories--Light

[[Page 74199]]

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 are interested 
in comment on this segmentation strategy (subcategorization). 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.
(1) What are the proposed CO2 and fuel consumption standards 
and their timing?
    In developing the proposed 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. The technologies that the agencies considered while setting 
the proposed vehicle-level standards include improvements in lower 
rolling resistance tires. The technologies that the agencies considered 
while setting the engine standards include engine friction reduction, 
aftertreatment optimization, among others. The agencies' evaluation 
indicates that these technologies are available today in the heavy-duty 
tractor and light-duty vehicle markets, but have very low application 
rates in the vocational market. The agencies have analyzed the 
technical feasibility of achieving the proposed 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 proposed 
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 proposed vocational 
vehicle standards in Section III.
(a) Proposed Chassis Standards
    As shown in Table II-9, EPA is proposing the following 
CO2 standards for the 2014 model year for the Class 2b 
through Class 8 vocational vehicle chassis. Similarly, NHTSA is 
proposing 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 proposed standard applies throughout the 
useful life of the vehicle.
    EPA and NHTSA are proposing more stringent vehicle standards for 
the 2017 model year which reflect the CO2 emissions 
reductions required through the 2017 model year engine standards. As 
explained in Section II. D. (2)(c)(iv) 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 manufacturers installing additional 
vehicle technologies.
[GRAPHIC] [TIFF OMITTED] TP30NO10.022

(i) Off-Road Vocational Vehicle Standards
    In developing  the proposal EPA and NHSTA received comment from 
manufacturers and owners that certain vocational vehicles sometimes 
have very limited on-road usage. These trucks are defined to be motor 
vehicles under 40 CFR 85.1703, but they will spend the majority of 
their operations off-road. Trucks, such as those used in oil fields, 
will experience little benefit from low rolling resistance tires. The 
agencies are therefore proposing to allow a narrow range of these de 
facto off-road trucks to be excluded from the proposed vocational 
vehicle standards because the trucks require special off-road tires 
such as lug tires. The trucks must still use a certified engine, which 
will provide fuel consumption and CO2 emission reductions to 
the truck in all

[[Page 74200]]

applications. To insure that these trucks are in fact used chiefly off-
road, the agencies are proposing requirements that the vehicles have 
off-road tires, have limited high speed operation, and are designed for 
specific off-road applications. The agencies are specifically proposing 
that a truck must meet the following requirements to qualify for an 
exemption from the vocational vehicle standards:
---------------------------------------------------------------------------

    \79\ Manufacturers may voluntarily opt-in to the NHTSA fuel 
consumption program in 2014 or 2015. If a manufacturer opts-in, the 
program becomes mandatory.
---------------------------------------------------------------------------

     Installed tires which are lug tires or contain a speed 
rating of less than or equal to 60 mph; and
     Include a vehicle speed limiter governed to 55 mph.
    EPA and NHTSA have concluded that the on-road performance losses 
and additional costs to develop a truck which meets these 
specifications will limit the exemption to trucks built for the desired 
purposes. The agencies welcome comment on the proposed requirements and 
exemptions.
(b) Proposed Heavy-duty Engine Standards
    EPA is proposing GHG standards \80\ and NHTSA is proposing 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. The agencies' analyses, as 
discussed briefly below and in more detail later in this preamble and 
in the draft RIA Chapter 2, show that these standards are appropriate 
and feasible under each agency's respective statutory authorities.
---------------------------------------------------------------------------

    \80\ Specifically, EPA is proposing CO2, 
N2O, and CH4 emissions standards for new 
heavy-duty engines over an EPA specified useful life period (see 
Section II. E. 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. In 
developing the proposed 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.
    With respect to the lead time and cost of incorporating technology 
improvements that reduce GHG emissions and fuel consumption, the 
agencies place important weight on the fact that during MYs 2014-2017, 
engine manufacturers are expected to redesign and upgrade their 
products only once. 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 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 proposed GHG and fuel consumption reductions, and to 
do this as part of the normal engine redesign process. This is an 
important aspect of the proposed 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. 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.
    EPA's existing criteria pollutant emissions regulations for heavy-
duty highway engines establish four regulatory categories (three for 
compression-ignition or diesel engines and one for spark ignition or 
gasoline engines) that represent the engine's intended and primary 
truck application, as shown in Table II-10 (40 CFR 1036.140). The 
agencies welcome comments on the existing definition of the regulatory 
categories (such as typical horsepower levels) as described in 40 CFR 
1036.140. All heavy-duty engines are covered either under the heavy-
duty pickup truck and van category or under the heavy-duty engine 
standards.
[GRAPHIC] [TIFF OMITTED] TP30NO10.023

    For the purposes of the GHG engine emissions and engine fuel 
consumption standards that EPA and NHTSA are proposing, the agencies 
intend to maintain these same four regulatory subcategories for GHG 
engine emissions standards and fuel consumption standards. This 
category structure would enable the agencies to set standards that 
appropriately reflect the technology available for engines for use in 
each type of vehicle.
(i) Diesel Engine Standards
    EPA's proposed heavy-duty diesel engine CO2 emission 
standards are presented in Table II-11. Similar to EPA's non-GHG 
standards approach, manufacturers may generate and use credits to show 
compliance with the standards. The EPA standards become effective in 
2014 model year, with more stringent standards becoming effective in 
model year 2017. Recently, EPA's

[[Page 74201]]

non-GHG heavy-duty engine program provided new emissions standards for 
the industry in three year increments. Largely, the heavy-duty engine 
and truck manufacturer product plans have fallen into three year cycles 
to reflect this environment. The proposed two-step CO2 
emission standards recognize the opportunity for technology 
improvements over this timeframe while reflecting the typical diesel 
truck manufacturer product plan cycles.
    NHTSA's fuel consumption standards, also presented in Table II-11, 
would contain voluntary engine standards starting in 2014 model year, 
with mandatory engine standards starting in 2017 model year, 
synchronizing with EPA's 2017 model year standards. A manufacturer may 
opt-in to NHTSA's voluntary standards in 2014, 2015 or 2016. Once a 
manufacturer opts-in, the standards become mandatory for the opt-in and 
subsequent model years, and the manufacturer may not reverse its 
decision. To opt into the program, a manufacture must declare its 
intent to opt in to the program with documented communication of the 
intent, at the same time it submits the Pre-Certification Compliance 
Report. See 49 CFR 535.8 for information related to the Pre-
Certification Compliance Report. A manufacturer opting into the program 
would begin tracking credits and debits beginning in the model year in 
which they opt into the program.
    The agencies are proposing the same standard level for the Light 
Heavy and Medium Heavy diesel engine categories. 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 the 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, which overall averaged 630 
g CO2/bhp-hr (6.19 gal/100 bhp-hr),\81\ in the 2010 model 
year. Furthermore, the technologies available to reduce fuel 
consumption and CO2 emissions from these two categories of 
engines are similar. The agencies are proposing to maintain these two 
separate engine categories with the same standard level (instead of 
combining them into a single category) to respect the different useful 
life periods associated with each category. The agencies are proposing 
to evaluate compliance with the LHD/MHD diesel engine standards based 
on the Heavy-duty FTP cycle.
---------------------------------------------------------------------------

    \81\ Calculated using the conversion 10,180 g CO2/
gallon for diesel fuel.
---------------------------------------------------------------------------

    The agencies found a difference in the baseline 2010 model year 
CO2 and fuel consumption performance between the LHD/MHD 
diesel engines, which averaged 630 g CO2/bhp-hr (6.19 gal/
100 bhp-hr),\82\ and the HHD diesel engines, which averaged 584 g 
CO2/bhp-hr (5.74 gal/100 bhp-hr). The HHD diesel engine data 
is also based on manufacturer submitted CO2 data for non-GHG 
emissions certification process. In addition, the agencies believe that 
there may be some technologies available to reduce fuel consumption and 
CO2 emissions that may not be appropriate for both the LHD/
MHD diesel and the HHD diesel engines, such as turbocompounding. 
Therefore, the agencies are proposing a standard level for HHD diesel 
engines which differs from the LHD/MHD diesel engine standard level 
likewise to be evaluated on the Heavy-duty FTP cycle.
---------------------------------------------------------------------------

    \82\ Calculated using the conversion 10,180 g CO2/
gallon for diesel fuel.
---------------------------------------------------------------------------

    We are proposing 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 some steady cruise conditions as 
represented on the Heavy-duty FTP. The primary reason the agencies are 
proposing to set two separate HHD diesel engine standards--one for HHD 
diesel engines used in tractors and the other for HHD 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. 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 line haul tractors would be required to meet the standard based on 
the SET, which is a steady state test cycle. On the other hand, 
vocational vehicles such as urban delivery trucks spend more time 
operating in transient conditions and may not realize the benefit of 
this type of technology in-use. The use of the Heavy-duty FTP for these 
engines would focus engine design on technologies that realize in-use 
benefits during the kind of operation typical for these engines. 
Therefore, we are proposing that engines installed in vocational 
vehicles be required to meet the standard and demonstrate compliance 
over the transient Heavy-duty FTP cycle. The levels of the standards 
reflect the difference in baseline emissions for the different test 
procedures.
    As noted in Section II.B above, the engine standards that EPA is 
proposing and the voluntary standards being proposed by NHTSA for the 
2014 model year would require diesel engine manufacturers to achieve on 
average a three percent reduction in fuel consumption and 
CO2 emissions over the baseline 2010 model year performance 
for the HHD diesel engines and a five percent reduction for the LHD and 
MHD diesel engines. The agencies' assessment of the NAS report and 
other literature sources indicates that there are technologies 
available to reduce fuel consumption by this level in the proposed 
timeframe in a cost-effective manner. These technologies include 
improved turbochargers, aftertreatment optimization, low temperature 
exhaust gas recirculation, and engine friction reductions. Additional 
discussion on technical feasibility is included in Section III below 
and in draft RIA Chapter 2.
    Additionally, the agencies are proposing that diesel engines 
further reduce fuel consumption and CO2 emissions in the 
2017 model year. The proposed 2017 model year standards for the LHD and 
MHD diesel engines represent a 9 percent reduction from the 2010 model 
year. The proposed reductions represent on average a five percent 
decrease over the 2010 baseline for HHD diesel engines required to test 
compliance using the Heavy-duty FTP test cycle. The additional 
reductions may be achieved through the increased development of the 
technologies evaluated for the 2014 model year standard. See draft RIA 
Chapter 2. The agencies' analysis indicates that this type of advanced 
engine development will require a longer development time than the 2014 
model year and therefore are proposing to provide additional lead time 
to allow for its introduction.
    Similar to EPA's non-GHG standards approach, manufacturers may 
generate and use credits by the same engine subcategory to show 
compliance with both agencies' standards.

[[Page 74202]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.024

    In proposing these standards for diesel engines used in vocational 
vehicles, the agencies have looked primarily at the typical performance 
levels of the majority of engines in the fleet. As explained above in 
Section II.B, we also recognize that when regulating a category of 
products for the first time, there will be individual products that may 
deviate from this baseline level of performance. Recognizing that for 
these products a reduction from the industry baseline may be more 
costly than the agencies have assumed or perhaps even not feasible in 
the lead time available for these standards, EPA and NHTSA are 
proposing a regulatory alternative whereby a manufacturer could comply 
with a unique standard based on a five percent reduction from the 
products own 2011 baseline level. Our assessment is that this five 
percent reduction is appropriate and technologically feasible given the 
manufacturers' ability to apply similar technology packages with 
similar cost to what we have estimated for the primary program. For 
this purpose, the agencies do not see that potential obstacles are 
greater or lesser for engine standards which are based on the SET 
procedure or Heavy-duty FTP cycle. We do not believe this alternative 
needs to continue past 2016 since manufacturers will have had ample 
opportunity to benchmark competitive products and make appropriate 
changes to bring their product performance into line with the rest of 
the industry.
    However, we are requesting comment on the potential to extend this 
regulatory alternative for one additional year for a single engine 
family with performance measured in that year as nine percent beyond 
the engine's own 2011 model year baseline level. We also request 
comment on the level of reduction beyond the baseline that is 
appropriate in this alternative. The five percent level reflects the 
aggregate improvement beyond the baseline we are requiring of the 
entire industry. As this provision is intended to address potential 
issues for legacy products that we would expect to be replaced or 
significantly improved at the manufacturer's next product change, we 
request comment if a two percent reduction would be more appropriate. 
We would consider two percent rather than five percent if we were 
convinced that making all of the changes we have outlined in our 
assessment of the technical feasibility of the standards was not 
possible for some engines due to legacy design issues that will change 
in the next design cycle. We are proposing that manufacturers making 
use of these provisions would need to exhaust all credits within this 
subcategory prior to using this flexibility and would not be able to 
generate emissions credits from other engines in the same regulatory 
subcategory as the engines complying using this alternate approach.
(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. Unlike the purpose-built heavy-duty diesel engines 
typical of this segment, these gasoline engines are developed for 
heavy-duty pickup trucks and vans primarily, but are also sold as loose 
engines to vocational vehicle manufacturers. Therefore, the agencies 
evaluated these engines in parallel with the heavy-duty pickup truck 
and van standard development. As with the pickup truck and van segment, 
the agencies anticipate that the manufacturers will have only one 
engine re-design within the 2014-18 model years under consideration 
within this proposal. In our meetings with all three of the major 
manufacturers in this 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 have concluded 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 proposing 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 proposed fuel consumption standard and 
EPA's proposed 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 (6.48 gal/100 bhp-hr) in 2010 based on non-GHG 
certification data provided to EPA by the manufacturers. The agencies 
propose that manufacturers achieve a five percent reduction in 
CO2 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. Additional 
detail on technology feasibility is included in Section III and in the 
draft RIA Chapter 2.
    NHTSA is proposing a 7.05 gallon/100 bhp-hr standard for fuel 
consumption while EPA is proposing 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 subcategory to show 
compliance with both agencies' standards.
    In the preceding section on diesel engines, we describe an 
alternative compliance approach for diesel engines based on 
improvements from an engine's own baseline of performance. We are not 
making a similar proposal for gasoline engines, but we request comment 
on the need for and appropriateness of such an approach. Comments 
suggesting the need for a

[[Page 74203]]

similar approach should include specific recommendations on how the 
approach would work and the technical reasons why such an approach 
would be necessary in order to make the gasoline engine standards 
feasible.
(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 is proposing would apply to individual vehicles and 
engines. NHTSA is not proposing to adopt in-use standards that would 
apply to the vehicles and engines in a similar fashion.
    EPA is proposing 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 and fuel consumption results. 
EPA is proposing a 2 percent adjustment factor for the in-use standard 
to provide some 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.
    EPA is proposing 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 proposes that the existing 
engine useful life periods, as included in Table II-12, be broadened to 
include CO2 emissions and fuel consumption for both engines 
and tractors (see 40 CFR 86.004-2). While NHTSA proposes to 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.025

    EPA requests comments on the magnitude and need for an in-use 
adjustment factor for the engine standard and the compliance model GEM, 
based chassis standard.
(2) Test Procedures and Related Issues
    The agencies are proposing 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 a 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 on which the proposed standard 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 proposing to 
set separate engine and vehicle-based emission standards. For the 
vocational vehicles, engine manufacturers would be subject to the 
engine standards, and chassis manufacturers would be required to 
install certified engines in their chassis. The chassis manufacturer 
would be subject to a separate vehicle-based standard that would use 
the proposed truck simulation model to evaluate the impact of the tire 
design to determine compliance with the truck 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 proposing 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 agencies developed the 
GEM for the specific purpose of this proposal 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 agencies and proposed 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 evaluating vehicle 
compliance without the overhead and costs of a more complicated model. 
Details of the model are included in Chapter 4 of the draft RIA.
    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 and NHTSA have validated GEM based on the chassis test results 
from three SmartWay certified tractors tested at Southwest Research 
Institute. The validation work conducted on these three vehicles is 
representative of the other Class 7 and 8 tractors. Many

[[Page 74204]]

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 is similar to the one used on 
a straight truck. Details of the validation testing and its 
representativeness are included in draft RIA Chapter 4. Overall, the 
GEM predicted the fuel consumption and CO2 emissions within 
4 percent of the chassis test procedure results for three test cycles--
the California ARB Transient cycle, the California ARB High Speed 
Cruise cycle, and the Low Speed Cruise cycle. These cycles are very 
similar to the ones the agencies are proposing to utilize in compliance 
testing. Test to test variation for heavy-duty vehicle chassis testing 
can be higher than 4 percent based on driver variation. The proposed 
simulation model is described in greater detail in draft RIA Chapter 4 
and is available for download by interested parties at (http://www.epa.gov/otaq/). We request comment on all aspects of this approach 
to compliance determination in general and to the use of the GEM in 
particular.
    The agencies are proposing 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. Tires 
are the only technology on which the agencies' own feasibility analysis 
for these vehicles is predicated. An example of the GEM input screen is 
included in Figure II-3. The input values for the simulation model 
would be derived by the manufacturer from tire test procedure proposed 
by the agencies in this proposal. The agencies are proposing that the 
remaining model inputs would be fixed values that are pre-defined by 
the agencies and are detailed in the draft RIA Chapter 4, including the 
engine fuel consumption map to be used in the simulation.
[GRAPHIC] [TIFF OMITTED] TP30NO10.026

(b)Tire Rolling Resistance Assessment
    As with the Class 7 and 8 combination tractors, NHTSA and EPA are 
proposing that the vocational vehicle's tire rolling resistance input 
to the GEM be determined using the ISO 28580:2009 test method.\83\ The 
agencies believe the ISO test procedure is appropriate to propose for 
this program because the procedure is the same one used by the NHTSA 
tire fuel efficiency labeling program \84\ and is consistent with the 
direction being taken by the tire industry both in the United States 
and Europe, and with the EPA SmartWay program. 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 vehicle. The results would be 
expressed as a rolling resistance coefficient and measured as kilogram 
per ton (kg/metric ton). The agencies are proposing 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 three 
tests would be the rolling resistance coefficient for the tire.
---------------------------------------------------------------------------

    \83\ 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.
    \84\ 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).
---------------------------------------------------------------------------

(c)Defined Vehicle Configurations in the GEM
    As discussed above, the agencies are proposing a methodology that 
chassis manufacturers would use to quantify the tire rolling resistance 
values to be input into the GEM. Moreover, the agencies are proposing 
to define the remaining

[[Page 74205]]

GEM inputs (i.e., specify them by rule), which may differ by the 
regulatory subcategory (for reasons described in the draft RIA). The 
defined inputs being proposed include the drive cycle, aerodynamics, 
truck curb weight, payload, engine characteristics, and drivetrain for 
each vehicle type, among others.
(i) Metric
    Based on NAS's recommendation and feedback from the heavy-duty 
truck industry, NHTSA and EPA are proposing 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 trucks 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.
(ii) Drive cycle
    The drive cycle being proposed for the vocational vehicles consists 
of the same three modes proposed for the Class 7-8 combination 
tractors. The agencies are thus proposing the use of 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. However, we are 
proposing different weightings for each mode than proposed for Class 7 
and 87 and 8 combination tractors, given the known difference in 
driving patterns between these two categories of vehicles. (The same 
reasoning underlies the agencies' proposal to use 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 two sources for mode 
weightings, as detailed in draft RIA Chapter 3. The agencies are 
proposing 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.\85\ The proposed weighted 
CO2 and fuel consumption value consists of 37 percent of 65 
mph Cruise, 21 percent of 55 mph Cruise, and 42 percent of Transient 
performance, which are reflected in the GEM.
---------------------------------------------------------------------------

    \85\ 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 proposing to specify each of 
these aspects of the vehicle. The agencies developed the truck curb 
weight inputs based on industry information developed by ICF.\86\ The 
proposed curb weights are 10,300 pounds for the LH trucks, 13,950 
pounds for the MH trucks, and 29,000 pounds for the HH trucks.
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    \86\ 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.
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    NHTSA and EPA are also proposing the following payload requirement 
for each regulatory category. The payloads were developed from Federal 
Highway statistics based on averaging the payloads for the weight 
categories represented within each vehicle subcategory.\87\ The 
proposed payload requirement is 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. Additional information is available in 
draft RIA Chapter 3.
---------------------------------------------------------------------------

    \87\ 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.
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(iv) Engine
    As the agencies are proposing separate engine and truck 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 proposing to use fixed values that are pre-defined 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 truck that uses an engine with emissions and fuel 
consumption better than the standards would require fewer vehicle 
reductions than those being proposed. The agencies are proposing that 
the engine characteristics used in GEM be representative of a diesel 
engine, because it represents the largest fraction of engines in this 
market.
    The agencies are proposing 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 proposed MY 2017 
standard). Effectively there is no change in stringency of the 
vocational vehicle standard (not including the engine) so that there is 
stability in the vocational vehicle (not including engine) standards 
for the full rulemaking period. These inputs are reasonable (indeed, 
seemingly necessitated) given the separate proposed regulatory 
requirement that vocational vehicle chassis manufacturers use only 
certified engines.
(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 proposing to 
specify the engine's fuel consumption map, drive cycle, and payload; 
therefore, it makes sense to specify the drivetrain that matches.
    In conclusion, for vocational vehicles, compliance would be 
determined by establishing values for the tire rolling resistance and 
using the prescribed inputs in GEM. The model would produce 
CO2 and fuel consumption results that would be compared 
against EPA's and NHTSA's respective standards.
(d) Engine Test Procedures
    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

[[Page 74206]]

evaluation of vehicles.\88\ An analogous metric for engines would be 
the amount of fuel consumed per unit of work. Thus, EPA is proposing 
that GHG emission standards for engines under the CAA would be 
expressed as g/bhp-hr: similarly, NHTSA's proposed fuel consumption 
standards under EISA would be represented as gallons of fuel per 100 
horsepower-hour (gal/100 bhp-hr). EPA's metric is also consistent with 
EPA's current standards for non-GHG emissions for these engines.
---------------------------------------------------------------------------

    \88\ See 2010 NAS Report, Note 19, page 39.
---------------------------------------------------------------------------

    EPA's criteria pollutant standards for engines 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. 
With regard to GHG and fuel consumption control, the agencies believe 
it is more 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.
    As discussed above, 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 benefits. We further 
explained why the Heavy-duty FTP is the appropriate test cycle for 
engines used in vocational vehicles, and the steady-state SET procedure 
the most appropriate for engines used in combination tractors. We are 
not concerned if off-cycle manufacturers further calibrate these 
designs 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. For example, as noted earlier, turbocompounding is one 
technology that the agencies have identified as a likely approach for 
compliance with our proposed HHD SET standard described below. 
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.
    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 are proposing to exclude the CO2 
emissions and fuel consumption increases due to regeneration from the 
calculation of the compliance levels over the defined test procedures. 
We considered including regeneration in the estimate of fuel 
consumption and GHG emissions and have 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 extended 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 timeframe of this proposal. 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. We are seeking 
comments regarding regeneration emissions and what approach if any the 
agencies should use in reflecting regeneration emissions in this 
program.
(e) Hybrid Powertrain Technology
    Although the proposed 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 proposing to provide credits for the use of hybrid 
powertrain technology as described in Section IV. The agencies are 
proposing that any credits generated using such technologies could be 
applied to any heavy-duty vehicle or engine, and not be limited to the 
vehicle category generating the credit. Section IV below also details 
the proposed approach to account for the use of a hybrid powertrain 
when evaluating compliance with the truck standard. In general, 
manufacturers can derive the fuel consumption and CO2 
emissions reductions based on comparative test results using the 
proposed chassis testing procedures. We are proposing the same three 
drive cycles and cycle weightings discussed for the vocational vehicles 
to evaluate trucks that use hybrid powertrains to power the vehicle 
during motive operation (such as pickup and delivery trucks and transit 
buses). However, we are proposing an additional PTO test cycle for 
trucks which use a PTO to power equipment while the vehicle is either 
idling or moving (such as bucket or refuse trucks). The reductions due 
to the hybrid technology would be calculated relative to the same type 
of vehicle with a conventional powertrain tested using the same 
protocol.
(3) Summary of Proposed Flexibility and Credit Provisions
    EPA and NHTSA are proposing a number of flexibility provisions for 
vocational vehicle chassis manufacturers and engine manufacturers, as 
discussed in Section IV below. These provisions are all based on an 
averaging, banking and trading program for emissions and fuel 
consumption credits. They include provisions to encourage the 
introduction of advanced technologies such as hybrid drivetrains, 
provisions to

[[Page 74207]]

incentivize early compliance with the proposed standards, and 
provisions to allow compliance using innovative technologies 
unanticipated by the agencies in developing this proposal.
(4) Deferral of Standards for Small Chassis Manufacturing and Small 
Engine Companies
    EPA and NHTSA are proposing 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.\89\ 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,\90\ and 
therefore that the exemption will have a negligible impact on the GHG 
emissions and fuel consumption improvements from the proposed 
standards.
---------------------------------------------------------------------------

    \89\ 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.
    \90\ 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.\91\ 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 proposed exemption from the standards 
established under this proposal would have a negligible impact on the 
GHG emissions and fuel consumption reductions otherwise due to the 
standards.
---------------------------------------------------------------------------

    \91\ 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 propose 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.

E. Other Standards Provisions

    In addition to proposing CO2 emission standards for 
heavy-duty vehicles and engines, EPA is also proposing separate 
standards for N2O and CH4 emissions.\92\ NHTSA is 
not proposing 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).\93\ EPA is proposing N2O and CH4 standards 
which apply to HD pickup trucks and vans as well as to all heavy-duty 
engines. EPA is not proposing 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.
---------------------------------------------------------------------------

    \92\ NHTSA's statutory responsibilities relating to reducing 
fuel consumption are directly related to reducing CO2 
emissions, but not to the control of other GHGs.
    \93\ N2O has a GWP of 298 and CH4 has a 
GWP of 25 according to the IPCC Fourth Assessment Report.
---------------------------------------------------------------------------

    EPA is requesting comment in Section II.E.4 below on possible 
alternative CO2 equivalent approaches to provide near-term 
flexibility for 2012-14 MY light-duty vehicles.
    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 nonmethane 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 proposed ``cap'' standards. The proposed standards would act 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 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 proposing the same 
standards for all of the model years to which the rules apply.
    EPA believes that the proposed N2O and CH4 
cap standards would 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 proposing that such an alternative

[[Page 74208]]

compliance approach be available to manufacturers to provide certain 
flexibilities for different technologies.
    EPA requests comments on the approach to regulating N2O 
and CH4 emissions including the appropriateness of ``cap'' 
standards, the technical bases for the levels of the proposed 
N2O and CH4 standards, the proposed test 
procedures, and the proposed timing for the standards. In addition, EPA 
seeks any additional emissions data on N2O and 
CH4 from current technology engines.
    EPA is basing its proposed N2O and CH4 
standards on available test data. We are soliciting 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 proposing 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 proposing assigned 
factors corresponding to no deterioration, as we are proposing for 
CO2, or for that matter to any predetermined level. We are 
therefore asking for comment on this subject.
    In addition to N2O and CH4 standards, this 
section also discusses air conditioning-related provisions and EPA's 
proposal to extend certification requirements to all-electric HD 
vehicles and vehicles and engines designed to run on ethanol fuel.
(1) What is EPA's proposed approach to controlling N2O?
    N2O is a global warming gas with a GWP of 298. It 
accounts for about 0.3% of the current greenhouse gas emissions from 
heavy-duty trucks.\94\
---------------------------------------------------------------------------

    \94\ 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 \95\ 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 proposed CO2eq 
option discussed in Section II.E.3.
---------------------------------------------------------------------------

    \95\ Memorandum ``N2O Data from EPA Heavy-Duty 
Testing''.
---------------------------------------------------------------------------

    EPA is proposing an N2O emission standard that we 
believe would be met by current-technology gasoline and diesel vehicles 
at essentially no cost. 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 proposed 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 proposed 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 proposed 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.
(a) Heavy-Duty Pickup Truck and Van N2O Exhaust Emission 
Standard
    EPA is proposing a 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 proposed 
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 proposed N2O 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.\96\ Manufacturers typically use design targets for 
NOX emission levels at approximately 50% 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 
proposing a more stringent

[[Page 74209]]

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.
---------------------------------------------------------------------------

    \96\ 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 
proposed 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 proposal.
    Overall, we believe that manufacturers of HD pickups and vans (both 
gasoline and diesel) would meet the proposed 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 is also proposing a per engine N2O emissions 
standard of 0.05 g/bhp-hr for heavy-duty engines which become effective 
in 2014 model year. These standards remain the same over the useful 
life of the engine. The N2O emissions would be measured over 
the 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. 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 proposed N2O level is twice the average 
N2O level of current diesel engines as demonstrated in the 
ACES Study and in EPA's testing of two additional engines with 
selective catalytic reduction aftertreatement systems.\97\ 
Manufacturers typically use design targets for NOX emission 
levels of about 50% 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. EPA requests comment on the 
agency's technical assessment of current and potential future 
N2O formation in heavy-duty engines, as presented here.
---------------------------------------------------------------------------

    \97\ 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.)
---------------------------------------------------------------------------

    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 proposing a consistent approach for heavy-duty engine 
manufacturers which allows them to delay direct measurement of 
N2O until the 2015 model year. EPA welcomes comments on 
whether there are differences in the heavy-duty market which would 
warrant a different approach.
    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 proposed program. EPA has 
established four separate N2O measurement methods, all of 
which are commercially available today. EPA expects that most 
manufacturers would use photo-acoustic measurement equipment, which EPA 
estimates would result in a one-time cost of about $50,000 for each 
test cell that would need to be upgraded.
    Overall, EPA believes that manufacturers of heavy-duty engines, 
both gasoline and diesel, would meet the proposed standard without 
implementing any new technologies, and beyond relatively small 
facilities costs for any companies that still need to acquire and 
install N2O measurement equipment, EPA does not project that 
manufacturers would incur significant costs associated with this 
proposed N2O standard.
    EPA is not proposing any vehicle-level N2O standards for 
heavy-duty trucks (combination and vocational) in this proposal. The 
N2O emissions would be controlled through the heavy-duty 
engine portion of the program. The only requirement of those truck 
manufacturers to comply with the N2O requirements is to 
install a certified engine.
(2) What is EPA's proposed approach to controlling CH4?
    CH4 is greenhouse gas with a GWP of 25. It accounts for 
about 0.03% of the greenhouse gases from heavy-duty trucks.\98\
---------------------------------------------------------------------------

    \98\ Value adapted from ``Inventory of U.S. Greenhouse Gas 
Emissions and Sinks: 1990-2007. April 2009.
---------------------------------------------------------------------------

    EPA is proposing 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 proposal. 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

[[Page 74210]]

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.\99\ However, CH4 emissions levels in the gasoline 
and diesel heavy-duty truck fleet have nevertheless 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.
---------------------------------------------------------------------------

    \99\ 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 gasoline or diesel equivalent vehicles, natural gas-fueled vehicles 
have historically produced 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 proposed 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 proposing 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 proposed standard would not result in additional testing costs. EPA 
requests comment on whether the proposed cap standard would result in 
any significant technological challenges for manufacturers of natural 
gas vehicles.
(a) Heavy-Duty Pickup Truck and Van CH4 Standard
    EPA is proposing a 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 
proposed CO2 standards. Similar to the CO2 
standard approach, the CH4 emission level of a vehicle would 
be a composite of the Light-duty FTP and HFET cycles with the same 55% 
city weighting and 45% highway weighting.
    The level of the proposed standard is approximately two times the 
average heavy-duty gasoline and diesel truck and van levels.\100\ As 
with N2O, this proposed level recognizes that manufacturers 
typically set emissions design targets with a compliance margin of 
approximately 50% of the standard. Thus, we believe that the proposed 
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 would also meet the proposed 
standard with a larger compliance margin resulting in no change in 
today's CH4 levels.
---------------------------------------------------------------------------

    \100\ Memorandum ``CH4 Data from 2010 and 2011 Heavy-
Duty Vehicle Certification Tests''.
---------------------------------------------------------------------------

(b) Heavy-Duty Engine CH4 Exhaust Emission Standard
    EPA is proposing a heavy-duty engine CH4 emission 
standard of 0.05 g/hp-hr as measured on the Heavy-duty FTP, to apply 
beginning in model year 2014. The proposed 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 proposal (see 40 CFR 86.007-
11).
    The level of the proposed CH4 standard is twice the 
average CH4 emissions from the four diesel engines in the 
ACES study.\101\ As with N2O, this proposed level recognizes 
that manufacturers typically set emission design targets at about 50% 
of the standard. Thus, EPA believes the proposed 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.
---------------------------------------------------------------------------

    \101\ Coordinating Researth 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 proposed standard would not result in additional testing costs.
    EPA is not proposing any vehicle-level CH4 standards for 
heavy-duty trucks (combination or vocational) in this proposal. The 
CH4 emissions would 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) Alternative CO2 Equivalent Option
    If a manufacturer is unable to meet the N2O or 
CH4 cap standards, EPA is proposing that the manufacturer 
may choose to comply using CO2 credits. In other words, a 
manufacturer could offset any N2O emissions or any 
CH4 emissions by taking steps to further reduce 
CO2. A manufacturer choosing this option would convert its 
measured N2O and CH4 test results 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.\102\ By using the 
Global Warming Potential of N2O and CH4, the 
proposed approach recognizes the inter-correlation of these elements in 
impacting global warming and is environmentally neutral to meeting the 
proposed individual emissions caps.
---------------------------------------------------------------------------

    \102\ N2O has a GWP of 298 and CH4 has a 
GWP of 25 according to the IPCC Fourth Assessment Report.
---------------------------------------------------------------------------

    The proposed 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 to the NHTSA fuel 
consumption standard.

[[Page 74211]]

(4) Light-Duty Vehicle N2O and CH4 Standards
    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 prevent future emissions increases, and were generally 
not expected to result in the application of new technologies for 
current vehicle designs or significant costs for the manufacturers. EPA 
also finalized an alternative CO2 equivalent standard 
option, which manufacturers may choose to use in lieu of complying with 
the otherwise-applicable N2O and CH4 standards. 
The CO2-equivalent standard option allows manufacturers to 
fold all N2O and CH4 emissions, on a 
CO2-equivalent 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).
    EPA has learned since the standards were finalized that some 
manufacturers may have difficulty meeting the N2O and/or 
CH4 standards in the early years of the program for a few of 
the vehicle models in their existing fleet. This is 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 
CO2 equivalent 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. 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. EPA believes this poses 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 were essentially cost free) but expects 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.
    Because EPA intended for these standards to be caps with little 
anticipated near-term impact on manufacturer's current product lines, 
EPA believes that it would be appropriate to provide additional 
flexibility in the near-term to allow manufacturers to meet the 
N2O and CH4 standards. EPA requests 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 N2O equivalent 
option including CH4, but choose to comply separately with 
the applicable N2O cap standard. EPA requests comments on 
allowing this approach in the light-duty program for MYs 2012-2014 as 
an additional flexibility to help manufacturers address any near-term 
issues that they may have with the N2O and CH4 
standards.
    EPA also requests comments on possible alternative approaches of 
providing additional near-term flexibility. For example, as discussed 
in Section II.E above, EPA is proposing for HD vehicles and engines to 
allow manufacturers to use CO2 credits, on a CO2 
equivalent basis, to offset N2O and CH4 emissions 
above the applicable standard. EPA requests comment on whether this 
approach would be appropriate for the light-duty program as an 
additional flexibility. Again, the additional flexibility would be 
limited to MYs 2012-2014 for the reasons discussed above. EPA notes 
that, after considering all relevant comments, provisions to address 
this issue may be finalized in an action independent of the heavy-duty 
rulemaking process in the interest of finalizing the provisions as soon 
as possible to provide manufacturers with certainty for MY 2012 light-
duty vehicles.
(5) EPA's Proposed 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.\103\ This 
includes the direct leakage of refrigerant as well as the subsequent 
leakage associate with maintenance and servicing, and with disposal at 
the end of the vehicle's life.\104\ The most commonly used refrigerant 
in automotive applications--R134a, has a high GWP of 1430.\105\ 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.
---------------------------------------------------------------------------

    \103\ The United States has submitted a proposal to the Montreal 
Protocol which, if adopted, would phase-out production and 
consumption of HFCs.
    \104\ The U.S. EPA has reclamation requirements for refrigerants 
in place under Title VI of the Clean Air Act.
    \105\ The global warming potentials used in the NPRM analysis 
are consistent with Intergovernmental Panel on Climate Change (IPCC) 
Fourth Assessment Report. At this time, the global warming potential 
values from the IPCC Second Assessment Report have been agreed upon 
as the official U.S. framework for addressing climate change. The 
global warming potential values from the IPCC Second Assessment 
Report are used in the official U.S. greenhouse gas inventory 
submission to the climate change framework. When inventories are 
recalculated for the final rule, changes in global warming potential 
may lead to adjustments.
---------------------------------------------------------------------------

    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 truck 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 proposing that truck manufacturers be required to 
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 proposing 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 consequent difficulties in developing a regulatory 
system.
    EPA is proposing a leakage standard which is a ``percent 
refrigerant leakage

[[Page 74212]]

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 proposing a standard of 
1.50 percent leakage per year for Heavy-duty Pickup Trucks and Vans and 
Class 7 and 87 and 8 Tractors. The proposed standard was derived from 
the vehicles with the largest system refrigerant capacity based on the 
Minnesota GHG Reporting database.\106\ The average percent leakage per 
year of the 2010 model year vehicles is 2.7 percent. This proposed 
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 is seeking comment on whether the stringency of a single 
``percent refrigerant leakage per year'' standard fairly addresses the 
range of system refrigerant capacities likely to be used in heavy-duty 
trucks.\107\ Since systems with less refrigerant may have a larger 
percentage of their annual leakage from the compressor shaft seal than 
systems with more refrigerant capacity, their relative percent 
refrigerant leakage per year could be higher, and a more extensive 
application of leakage reducing technologies could be needed to meet 
the standard). EPA welcomes comments relative to the stringency of the 
standard, and on whether manufacturers who adopt measures that improve 
the global warming impact of leakage emissions substantially beyond 
that achieved by the proposed standard should in some way be credited 
for this improvement.
---------------------------------------------------------------------------

    \106\ The Minnesota refrigerant leakage data can be found at 
http://www.pca.state.mn.us/climatechange/mobileair.html#leakdata.
    \107\ Society of Automotive Engineers Surface Vehicle Standard 
J2727, issued August 2008, http://www.sae.org.
---------------------------------------------------------------------------

    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-GWP 
refrigerant. 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.\108\ 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 does anticipate that updates to 
the SAE J2727 standard will be forthcoming (to address new materials 
and components which perform better than those originally used in the 
SAE analysis), and that it will be appropriate to include these updates 
in the regulations concerning refrigerant leakage.
---------------------------------------------------------------------------

    \108\ Team 1--Refrigerant Leakage Reduction: Final Report to 
Sponsors, SAE, 2007.
---------------------------------------------------------------------------

    Consistent with the 2012-2016 light-duty GHG 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. Time based learning is considered appropriate for A/C leakage 
control, so costs in the 2017 model year would 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 proposed rules.
    EPA proposes that manufacturers demonstrate improvements in their 
A/C system designs and components through a design-based method. The 
proposed 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 proposed approach, manufacturers would choose 
from a menu of A/C equipment and components used in their vehicles in 
order to establish leakage scores, which would 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 GHG rule, EPA is proposing that a 
manufacturer would 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 proposed approach would 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 truck program, 
the total A/C leakage score would 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 would result in 
estimates of likely leakage emissions reductions that would be 
comparable to those that would eventually result from performance-based 
testing. At the same time, comments are encouraged on all developments 
that may lead to a robust, practical, performance-based test for 
measuring A/C refrigerant leakage emissions.
    CO2 emissions are also associated with air conditioner 
efficiency, since air conditioners create load on the engine. See 74 FR 
49529. However, EPA is not proposing to set air conditioning efficiency 
standards for vocational vehicles and combination tractors. The 
CO2 emissions due to air conditioning systems in these 
heavy-duty trucks are minimal compared to their overall emissions of 
CO2. For example, EPA conducted modeling of a Class 8 
sleeper cab using 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% 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.
    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 GHG rule, where we require that manufacturers 
attest to the durability of

[[Page 74213]]

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
    As just noted, 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.
    Due to the complexity of the heavy-duty market, it is difficult to 
estimate with any degree of precision what the actual impact of 
indirect emissions are across the vastly different applications and 
duty cycles of heavy-duty trucks. Depending on application, geographic 
location and even seasonal usage relationships, A/C systems usage will 
vary differently across the heavy-duty fleet and therefore efficiency 
improvements will also result in different indirect emission 
reductions. Moreover, as just stated, indirect A/C emissions from 
vocational vehicles and combination tractors are very small relative to 
total GHG emissions from these vehicles. For these reasons, EPA is not 
proposing an indirect emission standard like we have proposed for 
direct emissions from heavy-duty vehicles.
    Instead, EPA is seeking comment on the applicability of an indirect 
emissions credit for A/C system efficiency improvements specifically in 
the heavy-duty pickup trucks and vans (i.e., Class 2b and 3). These 
vehicles are most closely related to their light-duty counterparts that 
have an indirect emissions credit program established under the 2012-
2016 MY Light-duty Vehicle Rule. It is likely that the light-duty and 
heavy-duty vehicles can share components used to improve the A/C system 
efficiency and reduce indirect A/C emissions. EPA also seeks comment on 
the level of the credit and if the fleet CO2 target 
standards should be adjusted accordingly to reflect expected A/C 
efficiency improvements similar to the approach used in the light-duty 
rule.
(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. We are proposing to 
revise 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 
would 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 would remain 
optional for all criteria pollutants through the 2015 model year.
    This change would primarily affect 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 would also be 
impacted, as they would need to comply with requirements for operation 
both on gasoline and ethanol.
    We are proposing that the specific regulatory requirements for 
certification on ethanol follow those already established for methanol, 
such as certification to NMHC equivalent standards and waiver of 
certain requirements. We would 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 would also follow light-duty precedents, primarily 
calling on manufacturers to exercise good engineering judgment in 
applying the regulatory requirements, but would not be allowed to 
generate NOX or PM credits.
    This proposed 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 proposed in connection with this proposed 
provision. We expect that there would be strong incentives for any 
manufacturers seeking to market these vehicles to also want them to be 
certified: (1) Uncertified vehicles would 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 would not be 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 would not be needed; in fact the highly integrated nature of 
modern automotive products make the emission control systems essential 
to reliable vehicle performance.
    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. EPA requests comment on 
this proposed application of its emission standards to HD vehicles and 
engines, regardless of the fuels they operate on.

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 proposed 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 proposed standards based on application of 
technology in light of the attribute based distinctions and related 
compliance measurement procedures. We also discuss consideration of 
standards that are either more or less stringent than those proposed.
    This proposal 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. The decision on what 
standard to set is guided by each agency's statutory

[[Page 74214]]

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 proposed rulemaking.
    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 proposed 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. 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 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 the 
lead time required.
    As described below, the vast majority of technology required by 
this proposal is commercially available and already being utilized to a 
limited extent across the fleet. Therefore the majority of the emission 
and fuel consumption reductions which would result from these proposed 
rules would result from the increased use of these technologies. EPA 
and NHTSA also believe that these proposed rules would 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 
fundamental changes in the engine or trucks' performance. Put another 
way, none of the technology pathways underlying the proposed 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

[[Page 74215]]

vehicle cost to technologies which maintain freight utility.
    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 fuel economy and GHG final 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 
2012-2016 MY light-duty GHG 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 2008 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 draft RIA, rather than using the traditional Retail 
Price Equivalent (RPE) multiplier approach. For the heavy-duty pickup 
truck and van cost projections in this proposal, 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 proposal, 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.\109\ 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.
---------------------------------------------------------------------------

    \109\ 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 draft RIA. In addition, for details 
on the ICMs, please refer to the RTI report that has been placed in the 
docket. The agencies request comment on all aspects of the cost 
analysis, including the adjustment factors used in the RTI analysis--
the levels associated with R&D, warranty, etc.--and whether those are 
appropriate or should be revised. If commenters suggest revisions, the 
agencies request supporting arguments and/or documentation.
    EPA and NHTSA believe that the emissions reductions called for by 
the proposed standards are technologically feasible at reasonable costs 
within the lead time provided by the proposed 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 agencies request comment on the methods and assumptions used to 
estimate costs, benefits, and technology cost-effectiveness for the 
main proposal and all of the alternatives. The agencies also seek 
comment on whether finalizing a different alternative stringency level 
for certain regulatory categories would be appropriate given agency 
estimates of costs and benefits.
    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 draft RIA Chapter 2.

A. Class 7-8 Combination Tractor

    Class 7 and 8 tractors are used in combination with trailers to 
transport freight.\110\ The variation in the design of these tractors 
and their typical uses drive different technology solutions for each 
regulatory subcategory.
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    \110\ ``Tractor'' is defined in proposed section 1037.801 to 
mean ``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.''
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    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 
recent National Academy of Sciences report of Technologies and 
Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty 
Vehicles,\111\ TIAX's assessment of technologies to support the NAS 
panel report,\112\ EPA's Heavy-duty Lumped Parameter Model,\113\ the 
analysis conducted by the Northeast States Center for a Clean Air 
Future, International Council on Clean Transport, Southwest Research 
Institute and TIAX for reducing fuel consumption of heavy-duty long 
haul combination tractors (the NESCCAF/ICCT study),\114\ and the 
technology cost analysis conducted by ICF for EPA.\115\ 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

[[Page 74216]]

identified the potential cost of such technologies. The NAS panel 
contracted TIAX to perform an assessment of technologies and their 
associated capital costs which provide potential fuel consumption 
reductions in heavy-duty trucks and engines. 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 to specifically 
address the effectiveness and interactions of the proposed pickup truck 
and light heavy-duty engine technologies. The NESCAFF/ICCT study 
assessed technologies available in the 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.
---------------------------------------------------------------------------

    \111\ 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.
    \112\ TIAX, LLC. Assessment of Fuel Economy Technologies for 
Medium- and Heavy-Duty Vehicles. November 2009.
    \113\ U.S. EPA. Heavy-duty Lumped Parameter Model.
    \114\ NESCCAF, ICCT, Southwest Research Institute, and TIAX. 
Reducing Heavy-Duty Long Haul Combination Truck Fuel Consumption and 
CO2 Emissions. October 2009.
    \115\ 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-2010-0162-0044.
---------------------------------------------------------------------------

(1) What technologies did the agencies consider to reduce the 
CO2 emissions and fuel consumption of 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 are premised on use of these technologies. 
The agencies note that SmartWay trucks are available today which 
incorporate the technologies that the agencies are considering as the 
basis for the standards in this proposal. We will also discuss other 
technologies that could potentially be used, such as vehicle speed 
limiters, although we are not basing the proposed standards on their 
use for the model years covered by this proposal, 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 kinds of 
technologies that could be used to improve performance relative to this 
baseline.
(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 classic styling, or may be sold with conventional or SmartWay 
aerodynamic packages. Based on our review of current truck model 
configurations and Polk data provided through MJ Bradley,\116\ we 
believe the aerodynamic configuration of the baseline new truck fleet 
is approximately 25 percent classic, 70 percent conventional, and 5 
percent SmartWay (as these 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 
``conventional'' 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,\117\ 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.
---------------------------------------------------------------------------

    \116\ MJ Bradley. Heavy-duty Market Analysis. May 2009. Page 10.
    \117\ US 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.\118\ The GEM demonstrates that an aerodynamic improvement of a 
Class 8 high roof sleeper cab with a Cd value from 0.60 (which 
represents a SmartWay tractor) provides a 5% reduction in fuel 
consumption and CO2 emissions over a truck with a Cd of 
0.68.
---------------------------------------------------------------------------

    \118\ TIAX. ``Assessment of Fuel Economy Technologies for 
Medium- and Heavy-Duty Vehicles'', TIAX LLC, November 19, 2009. 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% 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.\119\ 
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.\120\ Low 
rolling resistance (LRR) drive tires are currently offered in both dual 
assembly and single wide-base configurations. Single wide tires can 
offer both the rolling resistance reduction along with improved 
aerodynamics and weight reduction. The GEM demonstrates that replacing 
baseline tractor tires with tires which meet the SmartWay level 
provides a 4% reduction in fuel consumption and CO2 
emissions over the prescribed test cycle.
---------------------------------------------------------------------------

    \119\ See SmartWay, Note 117, above.
    \120\ 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, the agencies 
considered evaluating vehicle mass reductions on a total vehicle basis 
for tractors and vocational trucks.\121\ The agencies considered 
defining a baseline vehicle curb weight and the GEM model 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

[[Page 74217]]

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 and for vocational trucks 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.
---------------------------------------------------------------------------

    \121\ 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 are proposing. We reflect 
mass reductions for specific technology substitutions (e.g., installing 
aluminum wheels instead of steel wheels) where we can 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 are accounting for mass reductions where we can accurately 
account for its benefits. In the future, if we are able to develop an 
appropriate vehicle mass baseline for the diversity of vehicles within 
a segment and therefore could reasonable project overall mass 
reductions that would not inadvertently reduce customer utility, we 
would consider setting standards that take into account overall vehicle 
mass reductions. The agencies' baseline tire and wheel package consists 
of dual tires with steel wheels. A tractor's empty curb weight can be 
reduced from the replacement of dual tires with single wide tires and 
with the replacement of steel wheels with high strength steel or 
aluminum. Analysis of literature indicates that there is opportunity to 
reduce typical tractor curb weights by 80 to 670 pounds, or up to 
roughly 3 percent, through the use of lighter weight wheels and single 
wide tires, as described in draft RIA Chapter 2. High strength steel, 
aluminum, and light weight aluminum alloys provide opportunities to 
reduce the truck's mass relative to steel wheels. In addition, single 
wide tires (a single wide-based tire which replaces two standard tires 
in each wheel position) provide the opportunity to reduce the overall 
mass of wheels and tires due to the replacement of dual tires with 
singles. On average, these technologies together can reduce weight by 
over 400 pounds. A weight reduction of this magnitude 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 for 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.
    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.\122\ EPA and NHTSA agree 
with the TIAX assessment of a 6 percent reduction in overall fuel 
consumption reduction.\123\
---------------------------------------------------------------------------

    \122\ See the draft RIA Chapter 2 for details.
    \123\ See the 2010 NAS Report, Note 111, 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, 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 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.
    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.\124\ 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. While we 
believe there may be real benefits in reduced fuel consumption and GHG 
emissions through the application of automatic or automated manual 
transmission technology, we are not proposing to reflect that potential 
improvement in our standard setting nor in our compliance model. We 
have taken this approach because we cannot say with confidence what 
level of performance improvement to expect. However, we welcome 
comments on this decision supported where possible with data. If a 
clear measure of performance improvement can be defined for the use of 
automatic or automated manual transmission technologies, we will 
consider reflecting the technology in setting the stringency of the 
standards and in determining compliance with the standards.
---------------------------------------------------------------------------

    \124\ See TIAX, Note 112, 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.\125\ The light-duty fuel economy and GHG final 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. The 
agencies are interested in comments on whether low friction lubricants 
should be included in the technologies modeled in GEM to obtain 
certification values for fuel consumption and CO2 emissions 
and how manufacturers could ensure the use of these lubricants for the 
full useful life of the truck.
---------------------------------------------------------------------------

    \125\ See the 2010 NAS Report, Note 111, 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, which are 
already included as a separate technology in the agencies' technology 
assessment. NAS estimated that hybrid systems would cost approximately 
$25,000 per truck in the 2015 through 2020 timeframe and

[[Page 74218]]

provide a potential fuel consumption reduction of 10 percent, of which 
6 percent is idle reduction which can be achieved through other idle 
reduction technologies.\126\ 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 
proposal, 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.
---------------------------------------------------------------------------

    \126\ See the 2010 NAS Report, Note 111, 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 draft 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 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 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.
    Engine performance for CO2 emissions and fuel consumption can be 
improved by use of the following technologies:
    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.\127\ 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.
---------------------------------------------------------------------------

    \127\ TIAX Assessment of Fuel Economy Technologies for Medium 
and Heavy-duty Vehicles, Report to National Academy of Sciences, Nov 
19, 2009, Page 4-2.
---------------------------------------------------------------------------

    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.\128\ 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.
---------------------------------------------------------------------------

    \128\ TIAX Assessment of Fuel Economy Technologies for Medium 
and Heavy-duty Vehicles, Report to National Academy of Sciences, Nov 
19, 2009, 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 0.5 to 1.5 
percent.\129\
---------------------------------------------------------------------------

    \129\ TIAX, Assessment of Fuel Economy Technologies for Medium- 
and Heavy-duty Vehicles, Final Report, Nov. 19, 2009, pg 4-15.
---------------------------------------------------------------------------

    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 are considering 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.\130\ 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.\131\ The agencies estimate 
an additional 1 to 2 percent reduction may be feasible in the 2017 
model year through additional refinement.
---------------------------------------------------------------------------

    \130\ 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, US Department of Energy. Pp 113-116. 
December 2008.
    \131\ TIAX Assessment of Fuel Economy Technologies for Medium 
and Heavy-duty Vehicles, Report to National Academy of Sciences, Nov 
19, 2009, pg. 4-9.
---------------------------------------------------------------------------

    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.\132\
---------------------------------------------------------------------------

    \132\ TIAX. Assessment of Fuel Economy Technologies for Medium- 
and Heavy-Duty Vehicles. November 2009. Page 4-13.
---------------------------------------------------------------------------

    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

[[Page 74219]]

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.\133\
---------------------------------------------------------------------------

    \133\ TIAX. November 2009. Page 3-5.
---------------------------------------------------------------------------

    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.\134\ 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.
---------------------------------------------------------------------------

    \134\ 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.\135\
---------------------------------------------------------------------------

    \135\ 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.\136\ However, none 
of the bottoming cycle or Rankine engine systems has been demonstrated 
commercially and are currently in only the research stage.
---------------------------------------------------------------------------

    \136\ See 2010 NAS Report, Note 111, page 57.
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(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' timeframes through the increased application of 
aerodynamic technologies, LRR tires, weight reduction, extended idle 
reduction technologies, vehicle speed limiters, and engine 
improvements. As discussed above, the agencies believe that hybrid 
powertrains in tractors will not be cost-effective in the time frame of 
the rules. The agencies also are not proposing to include drivetrain 
technologies in the standard setting process, as discussed in Section 
II.
    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 proposed 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 GEM. 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 exhaust stacks at the B-pillar, which 
increase drag. The agencies consider a baseline truck as having 
``conventional'' aerodynamic package, though today there is a large 
spread in aerodynamics in the new tractor fleet. As noted earlier, our 
assessment of the baseline new truck fleet aerodynamics represents 
approximately 25 percent classic, 70 percent conventional, and 5 
percent SmartWay. This mix of vehicle aerodynamics provides a Cd 
performance level slightly greater than the ``conventional aerodynamic 
package'' Cd value (for example the baseline high roof tractor has a Cd 
of 0.69 while the same tractor category with a conventional aerodynamic 
package has a Cd of 0.68). 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.\137\ The agencies use the 
inputs described in GEM to derive the baseline CO2 emissions 
and fuel consumption of Class 7 and 8 tractors. The results are 
included in Table III-2.
---------------------------------------------------------------------------

    \137\ 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.

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[[Page 74220]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.027

[GRAPHIC] [TIFF OMITTED] TP30NO10.028

(ii) Tractor Technology Package Effectiveness
    The agencies' assessment of the proposed 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 technology performance characteristics for each subcategory, 
described below. Each technology consists of an input parameter which 
is in turn modeled in GEM. Table III-3 describes our proposed model 
inputs for the range of Class 7 and 8 tractor aerodynamic packages and 
vehicle technologies. This was combined with a projected technology 
application rate to determine the stringency of the proposed standard.
    The aerodynamic packages are categorized as Classic, Conventional, 
SmartWay, Advanced SmartWay, and Advanced SmartWay II. The Classic 
aerodynamic package refers to traditional styling such as a flat front, 
exposed air cleaners and exhaust stacks, among others. The conventional 
package refers to an overall aerodynamic appearance and best represents 
the aerodynamics of the majority of new tractor sales. The SmartWay 
aerodynamic package includes technologies such as roof fairings, 
aerodynamic hoods, aerodynamic mirrors, chassis fairings, and cab 
extenders. The Advanced SmartWay and Advanced SmartWay II packages 
reflect different degrees of new aerodynamic technology development 
such as active air management. A more complete description of these 
aerodynamic packages is included in Chapter 2 of the draft RIA. In 
general, the coefficient of drag values for each package and tractor 
subcategory were developed from EPA's coastdown testing of tractor-
trailer combinations, the 2010 NAS report, and SAE papers.
    The rolling resistance coefficient for the tires was developed from 
SmartWay's tire testing to develop the SmartWay certification. The 
benefits for the extended idle reductions were developed from 
literature, SmartWay work, and the 2010 NAS report. The weight 
reductions were developed from manufacturer information.

[[Page 74221]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.029

(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.
---------------------------------------------------------------------------

    \138\ Vehicle speed limiters are an applicable technology or all 
Class 7 and 8 tractors, however the standards are not premised on 
the use of this technology.
---------------------------------------------------------------------------

    With respect to the levels of technology application used to 
develop the proposed 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 
proposed standards.
    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 
proposing 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.\139\ EPA and NHTSA are proposing that 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 proposed standard is premised) to consist of 20 percent of Advanced 
SmartWay, 70 percent SmartWay, and 10 percent conventional reflecting 
our assessment of the fraction of tractors in this segment that can

[[Page 74222]]

successfully apply these aerodynamic packages. The small percentage of 
conventional truck aerodynamics reflects applications including 
tractors serving as refuse haulers which spend a portion of their time 
off-road at the landfill and generally operate at lower speeds with 
frequent stops--further reducing the benefit of aggressive aerodynamic 
technologies. Features such as chassis skirts are prone to damage in 
off-road applications; therefore we are not proposing standards that 
are based on all trucks having chassis skirts or achieving GHG 
reductions premised on use of such technology. The 90 percent of 
tractors that we project can either be SmartWay or Advanced SmartWay 
equipped reflects the bulk of Class 8 high roof sleeper cab 
applications. We are not projecting a higher fraction of Advanced 
SmartWay 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. 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. We request 
comment on our assessment of the potential for use of Advanced SmartWay 
technologies and the need for a fraction of these vehicles to continue 
to remain configured as conventional cabs due to their occasional use 
off-road.
---------------------------------------------------------------------------

    \139\ TIAX. Assessment of Fuel Economy Technologies for Medium- 
and Heavy-Duty Vehicles. November 2009. Page 4-40.
---------------------------------------------------------------------------

    The proposed 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.\140\ 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.
---------------------------------------------------------------------------

    \140\ U.S. Department of Energy. Transportation Energy Data 
Book, Edition 28-2009. Table 5.7.
---------------------------------------------------------------------------

    Trucks designed for on/off-road application may be restricted in 
the ability to improve the aerodynamic design of the bumper, chassis 
skirts, air cleaners, and other aspects of the truck which would 
typically be needed to move a conventional truck into the SmartWay bin. 
First, off-road applications may require the use of steel bumpers which 
tend to be less aerodynamic than plastic designs. Second, ground 
clearance may be an issue for some off road applications due to poor 
road surface quality. This may pose a greater likelihood that those 
items such as chassis skirts would incur damage in use and therefore 
would not be a technology desirable in these applications. Third, the 
trucks used in off-road applications may also experience dust which 
requires an additional air cleaner to manage the dirt. Fourth, some 
trucks are used in applications which require heavier load capacity, 
such as those with gross combined weights of greater than 80,000 
pounds, which is today's Federal highway limit. Often these trucks are 
configured with different axle combinations than those traditionally 
used on-road. These trucks may contain either a lift axle or spread 
axle which allows for greater carrying capability. Both of these 
configurations limit the design and effectiveness of chassis skirts. 
Lastly, some work trucks require the use of PTO operation or access to 
equipment which may limit the application of side extenders and chassis 
skirts.
    The agencies considered the on/off-road restriction to aerodynamic 
technology application, used VIUS estimate of approximately 35 percent 
of tractors may be used in this type of application, and used 
confidential data provided by truck manufacturers regarding the 
fraction of their current sales which go into the various applications, 
to project the aerodynamic application rates for each tractor category. 
For example, the agencies project that day cabs with low roofs will be 
used more often in these on/off-road applications than day cabs with 
high roof. Therefore, the agencies project technology application rate 
for conventional aerodynamics in day cab low roof as 40 percent while 
it would be 30 percent in day cab high roofs tractors. The agencies 
have also estimated that the development of advanced aerodynamic 
technologies would be applied first to high roof sleeper cabs and then 
follow with the other tractor categories. Therefore, the agencies 
propose to use a 10 percent application rate of the Advanced SmartWay 
aerodynamic technology package to the other tractor categories. The 
agencies welcome comment on our assessment of application rates and are 
interested in data that provide estimates on truck sales to the various 
applications where aerodynamics are less effective or restricted.
    At least one LRR tire model is available today that meets the 
rolling resistance requirements of the SmartWay and Advanced SmartWay 
tire packages so the 2014 MY should afford manufacturers sufficient 
lead time to install these packages. However, tire rolling resistance 
is only one of 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 proposed standards should not be premised on 100 
percent application of LRR tires in all tractor segments. The agencies 
are proposing to base their analyses on application rates that vary by 
category and match the application rates used for the aerodynamic 
packages to reflect the on/off-road application of some tractors which 
require a different balancing of traction versus rolling resistance. We 
believe on- versus off-road traction (primarily tread pattern) is the 
only tire performance parameter which trades off with tire rolling 
resistance so significantly that tire manufacturers would be unable to 
develop tires meeting both the assumed lower rolling resistance 
performance while maintaining or improving other characteristics of 
tire performance. We seek comment on our assessment.
    Weight reductions can be achieved through single wide tires 
replacing dual tires and lighter weight wheel material. Single wide 
tires can reduce weight by over 160 pounds per axle. Aluminum wheels 
used in lieu of steel wheels will reduce weight by over 80 pounds for a 
dual wheel axle. Light weight aluminum steer wheels and aluminum single 
wide drive wheels and tires package available today would provide a 670 
pound weight reduction over the baseline steel steer and dual drive 
wheels. The

[[Page 74223]]

agencies recognize that not all tractors can or will use single wide 
tires, and therefore are proposing a weight reduction package of 400 
pounds. The agencies are proposing to use a 100 percent application 
rate for this weight reduction package. The agencies are unaware of 
reasons why a combination of lower weight wheels or tires cannot be 
applied to all combination tractors, but welcome comments.
    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 while 
providing certainty that the overnight idle operations will be 
eliminated. Therefore, we are allowing the installation of only an 
automatic engine shutoff, without override capability, to qualify for 
idle emission reductions in GEM to allow for aftermarket installations 
of idle reduction technology. We are proposing a 100 percent 
application rate for this technology for Class 8 sleeper cabs (note 
that the current fleet is estimated to have a 30 percent application 
rate). The agencies are unaware of reasons why extended idle reduction 
technologies could not be applied to all tractors with a sleeper cab, 
but welcome comments.
    Vehicle speed limiters may be used as a technology to meet the 
standard, but in setting the standard we assumed a 0 percent 
application rate of vehicles speed limiters. Although we believe 
vehicles 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 at 55 mph for this 
customer. The resulting truck modeled in GEM could meet our proposed 
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. We are seeking comment on 
the use of VSLs that cannot be overridden by the end-user as a means of 
compliance with our proposed standards.
    We have chosen not to assume the use of a mandatory vehicle speed 
limiter in our proposal 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. Setting a mandatory expected 
use of such VSL carries the risk of requiring VSL in situations that 
are not appropriate from an efficiency perspective. To avoid such 
possibility, the agencies are not premising the proposed standards on 
use of VSL, and instead will rely on the industry to select VSL when 
circumstances are appropriate for its use. 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. We welcome comments on our decision not to premise the 
emission standards on the use of VSLs.
    Table III-4 provides the proposed application rates of each 
technology broken down by weight class, cab configuration, and roof 
height.

[[Page 74224]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.030

(iv) Derivation of the Proposed Tractor Standards
    The agencies used the technology inputs and proposed technology 
application rates in GEM to develop the proposed fuel consumption and 
CO2 emissions standards for each subcategory of Class 7 and 
8 combination tractors. The agencies derived a scenario truck for each 
subcategory by weighting the individual GEM input parameters included 
in Table III-3 by 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 
proposed engine standards, the agencies assumed a compliant engine in 
GEM. In other words, EPA is proposing 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.\141\ The agencies then ran GEM with a single set 
of vehicle inputs, as shown in Table III-5, to derive the proposed 
standards for each subcategory. Additional detail is provided in the 
draft RIA Chapter 2.
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    \141\ As explained further in Section V below, EPA would use 
these inputs in GEM even for engines electing to use the alternative 
engine standard.

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[[Page 74225]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.031

    The level of the 2014 and 2017 model year proposed standards and 
percent reduction from the baseline for each subcategory is included in 
Table III-6.
[GRAPHIC] [TIFF OMITTED] TP30NO10.032

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

[[Page 74226]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.033

(v) Reasonableness of the Proposed Standards
    The proposed standards are based on aggressive application rates 
for control technologies which the agencies regard as the maximum 
feasible for the reasons given in Section (iii) above; see also draft 
RIA Chapter 2.5.8.2. These technologies, at the estimated application 
rates, are available within the lead time provided, as discussed in 
draft 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 $10 per ton of CO2eq per 
vehicle in 2030 without consideration of the substantial fuel 
savings.\142\ 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.\143\ Moreover, 
the cost of controls is recovered due to the associated fuel savings, 
as shown in the payback analysis included in Table VIII-8 located in 
Section VIII below. Thus, overall cost per ton of the rule, considering 
fuel savings, is negative--fuel savings associated with the rule more 
than offset projected costs by a wide margin. See Table VIII-5 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 proposed 
standards represent a reasonable choice under section 202(a) of the CAA 
and under NHTSA's EISA authority at 49 U.S.C. 32902(k)(2).
---------------------------------------------------------------------------

    \142\ See Section VIII.D below.
    \143\ 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.
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(vi) Alternative Tractor Standards Considered
    The agencies are not proposing 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. We welcome comments 
supplemented with data on each aspect of this determination most 
importantly on individual technology efficacy to reduce fuel 
consumption and GHGs as well was our estimates of individual technology 
cost and lead-time.
    The agencies considered proposing 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 proposing 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 offroad conditions. The agencies welcome comment on the application 
rates for each type of technology and for each tractor category. We 
have not proposed 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,

[[Page 74227]]

for example, that hybrid systems are being researched to capture and 
return energy for tractors that operate in gently rolling hills. 
However, it is not clear to us today that these systems will be 
generally applicable to tractors in the timeframe of this regulation. 
We seek comment on our assessment on the appropriateness of setting 
standards based on the use of hybrid technologies. Further, the 
agencies request comment supported by data regarding additional 
technologies not considered by the agencies in proposing these 
standards.
(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 0.2 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 0.2 g/bhp-hr NOX level, then the individual 
engine's CO2 result was adjusted to accommodate 
aftertreatment strategies that would result in a 0.2 g/bhp-hr 
NOX emission level as described in draft RIA Chapter 
2.4.2.1. The engine CO2 results were then sales weighted 
within each regulatory subcategory to develop an industry average 2010 
model year reference engine. While 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.034

(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 draft 
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 proposal therefore reflects a 100 percent application rate of 
this technology package. The agencies gave consideration to proposing a 
more stringent standard based on the application of turbocompounding, 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 across the industry by model year 2014.
    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 proposing to set fuel 
consumption and CO2 emission standards recognizing the 
opportunity for technology improvements over this timeframe while 
reflecting the typical heavy-duty engine manufacturer product plan 
redesign and refresh cycles. Thus, the agencies are proposing to set 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 in draft RIA Chapter 2.4.2.12. The agencies' proposal is 
premised on a 100 percent application rate of this technology package. 
We gave consideration to proposing an even more stringent standard 
based on the use of advanced Rankine cycle (also called bottoming 
cycle) engine technology 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.\144\ Therefore, these 
technologies were not included in determining the stringency of the 
proposed 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 proposing 
provisions described in Section IV to create incentives for 
manufacturers to

[[Page 74228]]

continue to invest to develop this technology.
---------------------------------------------------------------------------

    \144\ 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 (page 4-
29).
---------------------------------------------------------------------------

(iii) Derivation of Engine Standards
    EPA developed the proposed 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 proposed standards 
are included in Table III-9.
[GRAPHIC] [TIFF OMITTED] TP30NO10.035

(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 proposal (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 
draft RIA Chapter 2.
    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 $6,750,000 per manufacturer per year over the 
five years covering 2012 through 2016. In aggregate, this averages out 
to $280 per engine during 2012 through 2016 using an annual sales value 
of 600,000 light-, medium- and heavy-HD engines. The agencies also are 
estimating costs of $100,000 per engine manufacturer per engine class 
(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 $4 per engine in 2013 using an annual sales value of 
600,000 light-, medium- and heavy-HD engines.
    Where we projected that additional new hardware was needed to the 
meet the proposed 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 include a low complexity ICM of 1.11 
and time based learning is considered applicable to each technology.

[[Page 74229]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.036

    The overall diesel engine technology package cost for a medium HD 
engine being placed in a combination tractor is $223 in the 2014 model 
year and $1,027 in the 2017 model year; for a heavy HD engine being 
placed in a combination tractor these costs are $145 and $955 in the 
2014 and 2017 model years, respectively. The differences for the medium 
HD engines are the valve train friction reduction costs of $78 in 2014 
($71 in 2017) that are not applied to heavy HD engines.
(v) Reasonableness of the Proposed Standards
    The proposed 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 proposal 
reflects 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,\145\ and the 
associated reductions are highly cost effective, an estimated $6 per 
ton of CO2eq per vehicle.\146\ 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.\147\ Even the more 
expensive 2017 MY proposed 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).
---------------------------------------------------------------------------

    \145\ 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.
    \146\ See Tractor CO2 savings and technology costs 
for Alternative 2 in Section IX.B.
    \147\ 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 (1)(b), notwithstanding the 
general reasonableness of the proposed 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 
proposed 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 proposed standards are 
based. Those technologies can be utilized by all engines 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 today. Manufacturers have been gradually replacing 
these legacy products with new engines. Engine

[[Page 74230]]

manufacturers have indicated to the agencies they will have to align 
their planned replacement of these products with our proposed standards 
and at the same time add additional technologies beyond those 
identified by the agencies as the basis for the proposed 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 proposing a 
similar approach here. As explained above in Section II B. (1) (b), the 
agencies are proposing 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 proposing an optional standard whereby manufacturers would 
elect to have designated engine families meet a standard of 3% 
reduction from their 2011 baseline emission and fuel consumption levels 
for that engine family. 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. As explained 
earlier, we are not proposing that the option to select an alternative 
standard continues 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 proposed 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, 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 75 FR 25417-25419 (similar approach for vehicles 
which are part of Temporary Lead Time Allowance under the light-duty 
vehicle rule). We are proposing that manufacturers can select engine 
families for this alternative standard without agency approval, but are 
proposing to require that manufacturers notify the agency of their 
choice and 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) Alternative Engine Standards Considered
    The agencies are not proposing engine standards less stringent than 
the proposed standards because the agencies believe these proposed 
standards are appropriate, highly cost effective, and technologically 
feasible, as just described. We welcome comments supplemented with data 
on each aspect of this determination most importantly on individual 
engine technology efficacy to reduce fuel consumption and GHG 
emissions. Comments should also address our estimates of individual 
technology cost and lead-time.
    The agencies considered proposing engine standards which are more 
stringent. Since the proposed standards reflect 100 percent utilization 
of the various technology packages, some additional technology would 
have to be added. The agencies are proposing 2017 model year standards 
based on the use of turbocompounding. 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 proposing this level of stringency because our 
assessment is that these technologies would not be available for 
production by the 2017 model year. The agencies welcome comments on 
whether waste heat recovery technologies are appropriate to consider 
for the 2017 model year standard, or if not, then when would they be 
appropriate.

B. Heavy-Duty Pickup Trucks and Vans

    This section describes the process the agencies used to develop the 
standards the agencies are proposing 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 
\148\ 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.\149\
---------------------------------------------------------------------------

    \148\ http://www.epa.gov/otaq/certdata.htm.
    \149\ 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

[[Page 74231]]

be used to model emissions and fuel consumption from a truck of the 
same basic body design, but with 4wd, a 4.10:1 axle ratio, and 8,500 lb 
test weight. The adjustment factors are 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.\150\
---------------------------------------------------------------------------

    \150\ 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 proposed 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, 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).
    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 proposed 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 
proposed standards.
    Since the manufacturers of HD pickups and vans generally only have 
one basic pick-up 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 
proposed standards would be feasible and appropriate by the 2018 model 
year.
    Although we did not determine that it was necessary for feasibility 
to apply varying technology penetration levels to different vehicles, 
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 proposing, 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 when the largest changes and reductions are expected 
to occur.
    The proposed 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.\151\ By expressing the proposed 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 proposal 
affords manufacturers substantial flexibility to satisfy the phase-in 
through a variety of pathways: 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.
---------------------------------------------------------------------------

    \151\ The NHTSA proposal provides voluntary standards for model 
years 2014 and 2015. NHTSA and EPA also propose to provide 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 timeframe, 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

[[Page 74232]]

consumption benefits, but we recognize that there is uncertainty at 
this time over the cost-effectiveness of these systems in heavy-duty 
applications, and over customer 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 timeframe, 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 proposed standards are premised are clearly available at 
reasonable cost in the 2014-2018 timeframe, 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 proposed standards. Our basis for these estimates is 
described in Section III.B.(1)(1) . 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.
    We solicit comment and new information that would aid the agencies 
in establishing the appropriate level of stringency for the HD pickup 
and van standards, and on all facets of the assessment described here 
and elsewhere in these rulemaking proposals.
(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. 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 proposal.
    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 proposed 
standards on a targeted switch in the mix of diesel and gasoline 
vehicles. We believe our proposed standards require similar levels of 
technology development and cost for both diesel and gasoline vehicles. 
Hence the proposed 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 proposing 
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 lubricant 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. 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.

[[Page 74233]]

     Six-, seven-, and eight-speed automatic transmissions--the 
gear ratio spacing and transmission ratio are optimized for a broader 
range of engine operating conditions.
    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 proposal.
    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.\152\
---------------------------------------------------------------------------

    \152\ See draft RIA Chapter 2.3 for fuller technology 
descriptions.
---------------------------------------------------------------------------

How did the agencies determine the costs and effectiveness of each of 
these technologies?
    Building on the technical analysis underlying the 2012-2016 MY 
light-duty vehicle rule, the agencies took a fresh look at technology 
cost and effectiveness values for purposes of this proposal. 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.\153\
---------------------------------------------------------------------------

    \153\ 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 2008 dollars using a ratio of gross domestic 
product (GDP) values for the associated calendar years,\154\ and 
indirect costs were accounted for using the new approach developed by 
EPA and used in the 2012-2016 light-duty 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.
---------------------------------------------------------------------------

    \154\ 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 2012-2016 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 
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

[[Page 74234]]

(and individual vehicles) might obtain from adding a fuel-saving 
technology. However, the agencies seek comment on whether additional 
levels of specificity beyond that already provided would improve the 
analysis for the final rules, and if so, how those levels of 
specificity should be analyzed.
    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. 
The agencies seek comment on the additional lifetime costs, if any, 
associated with the implementation of advanced technologies including 
maintenance and replacement costs. Based on comments, the agencies may 
decide to conduct additional analysis for the final rules regarding 
operating, maintenance and replacement costs.
(a) Engine Technologies
    NHTSA and EPA have reviewed the engine technology estimates used in 
the 2012-2016 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 proposal.
(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 2012-2016 MY light-duty 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 2008 dollars using the GDP price deflator and have used a 
markup of 1.17 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.155 156
---------------------------------------------------------------------------

    \155\ 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.
    \156\ 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.\157\ 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.
---------------------------------------------------------------------------

    \157\ ``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 2012-2016 light-duty final 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 2012-2016 MY light-duty vehicle rule, the 
agencies estimate the cost of this technology at $14 per cylinder 
compliance cost (2008$), including the low complexity ICM markup value 
of 1.17. 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.\158\ 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.\159\
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    \158\ Although couple cam phasing appears only in the single 
overhead cam and overhead valve branches of the decision tree, it is 
noted that a single phaser with a secondary chain drive would allow 
couple cam phasing to be applied to direct overhead cam engines. 
Since this would potentially be adopted on a limited number of 
direct overhead cam engines NHTSA did not include it in that branch 
of the decision tree.
    \159\ It is also noted that coaxial camshaft developments would 
allow other variable valve timing options to be applied to overhead 
valve engines. However, since they would potentially be adopted on a 
limited number of overhead valve engines, NHTSA did not include them 
in the decision tree.
---------------------------------------------------------------------------

    Based on the 2012-2016 light-duty final 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 and EPA reviewed this estimate for purposes of the NPRM, 
and continue to find it accurate.
    In the 2012-2016 light-duty final rule, the agencies estimated a 
$41 cost per cam phaser not including any markup (2007$). NHTSA and EPA 
believe that this estimate remains accurate. Using the new indirect 
cost multiplier of 1.17, for a low complexity technology, the 
compliance cost per cam phaser would be $46 (2008$) in the 2014 model 
year. Time-based learning is applied to this

[[Page 74235]]

technology. This technology was considered for gasoline engines only.
(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 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 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.
    NHTSA and EPA adjusted the 2012-2016 light-duty final rule 
estimates using updated power to weight ratings of heavy-duty trucks 
and confidential business information and confirmed a range of 3 to 4 
percent for these vehicles, though as mentioned above there is 
uncertainty over how often this technology would be exercised on the 
test cycles, and a lower range may be warranted for HD vehicles.
    NHTSA and EPA consider the costs for this technology to be 
identical to that for V8 engines on light-duty trucks. As such, the 
agencies have used the cost used in the 2012-2016 light-duty final 
rule. Using the new markup of 1.17 for a low complexity technology 
results in an estimate of $193 (2008$) in the 2014 model year. Time 
based learning is applied to this technology. This technology was 
considered for gasoline engines only.
(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 2012-2016 light-duty final 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 2012-2016 light-duty final 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 $395 (2008$) in the 2014 model 
year. Time based 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.\160\ 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.
---------------------------------------------------------------------------

    \160\ 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 timeframe. 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 
2012-2016 light-duty final rule. Based on confidential business 
information, 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

[[Page 74236]]

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 $110 (2008$) for a 2014 
model year truck or van. This estimate includes a low complexity ICM of 
1.17 and time based 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 
timeframe. These improvements include items such as improved combustion 
management, optimal turbocharger design, and improved thermal 
management. This technology was not considered in the 2012-2016 light-
duty final 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 $147 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, $94. All values are in 2008 dollars and 
are applicable in the 2014MY. Applying a low complexity ICM of 1.17 
results in a cost of $172 (2008$) applicable in the 2014MY. We consider 
time based learning to be appropriate for these technologies.
(c) Transmission Technologies
    NHTSA and EPA have also reviewed the transmission technology 
estimates used in the 2012-2016 light-duty final 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 this proposal.
(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 timeframe.
(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 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 final GHG 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.\161\
---------------------------------------------------------------------------

    \161\ 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% and a conversion from a 6 to 8-speed transmission to be 1.7%. 
While 8-speed transmissions were not considered in the 2012-2016 light-
duty final 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 timeframe. For this proposal, we are 
estimating the cost of an 8-speed automatic transmission at $231 
(2008$) 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 1.17 and time based learning. This 
technology applies to both gasoline and diesel 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 hydraulic power steering because of reduced 
overall accessory loads. This eliminates the parasitic losses

[[Page 74237]]

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 2012-2016 light-duty final rule estimated a 1 to 2 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 1.17, the estimated costs for this proposal 
are $108 for a MY 2014 truck or van (2008$). As EPS systems are in 
widespread usage today, time-based 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 them electrically, and only when needed (``on-demand'').
    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.\162\
---------------------------------------------------------------------------

    \162\ In the CAFE model, improved accessories refers 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 for this proposal.
    NHTSA and EPA jointly reviewed the estimates of 1 to 2 percent 
effectiveness estimates used in the 2012-2016 light-duty final rule and 
found them to be accurate for Improved Electrical Accessories. 
Consistent with the 2012-2016 light-duty final rule, the agencies have 
estimated the cost of this technology at $88 (2008$) including a low 
complexity ICM of 1.17. This cost is applicable in the 2014 model year. 
Improved accessory systems are in production currently and thus time-
based learning is applied. This technology was considered for diesel 
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.''Sec. \163\ 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.\164\ 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 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.
---------------------------------------------------------------------------

    \163\ ``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.
    \164\ ``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.

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[[Page 74238]]

    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 vehicle when all 
subsystems are redesigned to take into account the initial primary 
weight savings.165 166
---------------------------------------------------------------------------

    \165\ ``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.
    \166\ ``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 proposed 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% by 
2015.\167\ 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.\168\ Mazda plans to 
reduce vehicle weight by 220 pounds per vehicle or more as models are 
redesigned. 169, 170 Ducker International estimates that the 
average curb weight of light-duty vehicle fleet will decrease 
approximately 2.8% from 2009 to 2015 and approximately 6.5% 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.167 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 necessary 
for the work vehicle aspects.
---------------------------------------------------------------------------

    \167\ ``Lighten Up!,'' Brooke, L., Evans, H. Automotive 
Engineering International, Vol. 117, No. 3, March 2009.
    \168\ ``2008/9 Blueprint for Sustainability,'' Ford Motor 
Company. Available at: http://www.ford.com/go/sustainability (last 
accessed February 8, 2010).
    \169\ ``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).
    \170\ ``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/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% of 
the 2012-2016 light-duty final rule values due to the elimination of 
engine downsizing for this class of vehicle.
    Consistent with the 2012-2016 light-duty final rule, the agencies 
have estimated the cost of mass reduction at $1.32 per pound (2008$). 
For this analysis, the agencies are estimating a 5% mass reduction or, 
given the baseline weight of current trucks and vans, are estimating 
costs of $462, $544, $513, and $576 for Class 2b gasoline, 2b diesel, 3 
gasoline, 3 diesel trucks and vans, respectively. All values are in 
2008 dollars, are applicable in the 2014 model year and include a low 
complexity ICM of 1.17. Time based learning is considered applicable to 
mass reduction technologies.
    The agencies have recently completed work on an Interim Joint 
Technical Assessment Report that considers light-duty GHG and fuel 
economy standards for the years 2017 through 2025.\171\ In that report, 
the agencies have used updated cost estimates for mass reduction which 
were not available in time for use in this analysis but could be used 
in the final analysis. The agencies request comment on which mass 
reduction costs--those used in this draft analysis or those used in the 
Joint Technical Assessment Report--would be most appropriate for Class 
2b & 3 trucks and vans along with supporting information.
---------------------------------------------------------------------------

    \171\ ``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.
---------------------------------------------------------------------------

(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

[[Page 74239]]

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 2012-2016 light-
duty final rule.
    Based on the 2012-2016 light-duty final rule and the 2010 NAS 
Report, the agencies have estimated the cost for LRR tires to be $6 per 
Class 2b truck or van, and $9 per Class 3 truck or van.\172\ 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 learning is not applied. This 
technology is considered applicable to both gasoline and diesel.
---------------------------------------------------------------------------

    \172\ ``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.
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(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 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 2012-2016 light-duty final 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 2012-2016 light-duty final rule, the agencies 
have estimated the cost for this technology at $54 (2008$) including a 
low complexity ICM of 1.17. This cost is applicable in the 2014 model 
year to both gasoline and diesel trucks and vans.
(3) What are the projected technology packages' effectiveness and cost?
    The assessment of the proposed 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 proposed 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 proposed 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.

[[Page 74240]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.037

(4) Reasonableness of the Proposed Standards
    The proposed 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 draft RIA 
Chapter 2.3. These controls are estimated to add costs of approximately 
$1,249 to $1,592 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 21 MMT of CO2eq emissions over the lifetimes 
of 2014 through 2018 MY vehicles.\173\ The reductions are cost 
effective, estimated at $100 per ton of CO2eq removed in 
2030.\174\ 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 -$200 per ton of CO2eq in 
2030. The cost of controls is fully recovered due to the associated 
fuel savings, with a payback period within the fifth and sixth year of 
ownership, as shown in Table VIII-6 below. 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 
proposed 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).
---------------------------------------------------------------------------

    \166\ See Table VI-4.
    \167\ See Table VIII-3.
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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 parties such as body 
builders. These factors have led the agencies to propose a vehicle 
standard for vocational vehicles for the first phase of the program 
that relies on less extensive addition of technology as well as 
focusing on the chassis manufacturer as the manufacturer subject to the 
standard. We believe that future rulemakings will consider increased 
stringency and possibly more application-specific standards. The 
agencies are proposing standards for the diesel and gasoline engines 
used in vocational vehicles, similar to those discussed above for 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 proposed 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

[[Page 74241]]

engines--while spark ignition (or ``gasoline'') engines are a single 
regulatory subcategory. 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 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 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.\175\
---------------------------------------------------------------------------

    \175\ 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 timeframe.\176\ The agencies estimate that average rolling 
resistance from tires in 2010 model year can be reduced by 10 percent 
by 2014 model year based on the tire development achievements over the 
last several years in the line haul truck market which would lead to a 
2 percent reduction in fuel consumption based on GEM.
---------------------------------------------------------------------------

    \176\ See 2010 NAS Report, Note 111, page 146.
---------------------------------------------------------------------------

    Aerodynamics: The Argonne National lab work shows that aerodynamics 
have 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 truck. 
The agencies are not proposing to regulate body builders in this phase 
of regulations for the reasons discussed in Section II. Therefore, we 
are not basing any of the proposed 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 
proposed standards on use of vehicle weight reduction. Thus, vehicle 
mass reductions would not be input into GEM. The vocational vehicle 
models are not designed to be application-specific. Therefore weight 
reductions are difficult to quantify.
    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 
timeframe ranged between 2 and 8 percent.\177\ 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 transmissions for tractors). We 
have however decided not to do so for the following reasons.
---------------------------------------------------------------------------

    \177\ See 2010 NAS Report, Note 111, 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 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 proposing to reflect transmission and 
gear ratio optimization in our GEM model or in our standard setting.
    We are broadly seeking comment on our reasons for not reflecting 
these technology choices including recommendations for ways that the 
agencies could effectively reflect transmission related improvements. 
The agencies welcome comment on transmission and driveline technologies

[[Page 74242]]

specific to the vocational vehicle market that can achieve fuel 
consumption and GHG emissions reductions.
    Idle Reduction: Episodic idling by vocational vehicles occurs 
during the workday, unlike the overnight idling of combination 
tractors. 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.\178\ 
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. The use of hybrid powertrains to reduce idling is 
discussed below.
---------------------------------------------------------------------------

    \178\ Gaines, Linda, A. Vyas, J. Anderson (Argonne National 
Laboratory). Estimation of Fuel Use by Idling Commercial Trucks. 
January 2006.
---------------------------------------------------------------------------

    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 
three types of hybrid powertrain systems--hydraulic, electric, and 
plug-in electric. 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. 
The agencies are proposing to include hybrid powertrains as a 
technology to meet the vocational vehicle standard, as described in 
Section IV. However, the agencies are not proposing a vocational 
vehicle standard predicated on using a specific penetration of hybrids. 
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 timeframe--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 high 
hopes for future advancements in hybrid technologies to encourage their 
production through incentives. The agencies welcome comments on this 
approach.
(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 engine 
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 2012-2016 MY 
light-duty vehicle rule, the agencies took a fresh look at technology 
effectiveness values for purposes of this proposal using 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 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 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 engines) might obtain from 
adding a fuel-saving technology. However, the agencies seek comment on 
whether additional levels of specificity beyond that already provided 
would improve the analysis for the final rules, and if so, how those 
levels of specificity should be analyzed.
    Baseline Engine: Similar to the gasoline engine used as the 
baseline in the light-duty GHG rule, the agencies assumed the baseline 
engine in this segment to be a naturally aspirated, overhead valve V8 
engine. The following discussion of effectiveness is generally in 
comparison to 2010 baseline engine performance.
    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 \179\ and 
EEA \180\ 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.
---------------------------------------------------------------------------

    \179\ Northeast States Center for a Clean Air Future. ``Reducing 
Greenhouse Gas Emissions from Light-Duty Motor Vehicles.'' September 
2004.
    \180\ 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 2012-2016 MY light-
duty 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

[[Page 74243]]

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. 
Therefore, the agencies reduced the effectiveness assumed from this 
technology for trucks because of the lower displacement-to-weight ratio 
relative to light-duty vehicles. NHTSA and EPA adjusted the 2010 light-
duty vehicle final rule estimates using updated power to weight ratings 
of heavy-duty trucks and confidential business information and 
confirmed a range of 3 to 4 percent for these vehicles.
    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 2012-2016 MY light-duty vehicle final rule estimated the 
effectiveness 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 proposal. 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. 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.
    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 turbocompound 
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.\181\
---------------------------------------------------------------------------

    \181\ TIAX, Assessment of Fuel Economy Technologies for Medium- 
and Heavy-duty Vehicles, Final Report, Nov. 19, 2009, 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.\182\ 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.\183\ 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.
---------------------------------------------------------------------------

    \182\ 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.
    \183\ TIAX Assessment of Fuel Economy Technologies for Medium 
and Heavy-duty Vehicles, Report to National Academy of Sciences, Nov 
19, 2009, pg. 4-9.

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[[Page 74244]]

    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.\184\
---------------------------------------------------------------------------

    \184\ See 2010 NAS Report, Note 111, 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.\185\
---------------------------------------------------------------------------

    \185\ TIAX. 2009. Pages 3-5.
---------------------------------------------------------------------------

(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 GEM, as 
described in draft RIA Chapter 4.4.6. The agencies used a baseline 
rolling resistance coefficient for today's vocational vehicle fleet of 
9 kg/metric ton.\186\ 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 draft RIA Chapter 4. 
Using these values, the baseline performance of these vehicles is 
included in Table III-12.
---------------------------------------------------------------------------

    \186\ 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. Additional details are available in the 
draft RIA Chapter 2.
[GRAPHIC] [TIFF OMITTED] TP30NO10.038

(ii) Vocational Vehicle Technology Package
    The proposed program for vocational vehicles for this phase of 
regulatory standards is limited to 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). The agencies are seeking comment 
on the appropriateness of this approach.
    The assessment of the proposed technology effectiveness was 
developed through the use of the GEM. To account for the two proposed 
engine standards, EPA is proposing the use of a 2014 model year fuel 
consumption map in 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 
proposed for HD diesel engines, not the alternative standards.) EPA 
estimates that the rolling resistance of tires can be reduced by 10 
percent in the 2014 model year. The vocational vehicle standards for 
all three regulatory categories were determined using a tire rolling 
resistance coefficient of 8.1 kg/metric ton with a 100 percent 
application rate by the 2014 model year. The set of input parameters 
which are modeled in GEM are shown in Table III-13.
[GRAPHIC] [TIFF OMITTED] TP30NO10.039


[[Page 74245]]


    The agencies developed the proposed 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.040

(iii) Technology Package Cost
    EPA and NHTSA developed the costs of LRR tires based on the ICF 
report. The estimated cost per truck is $155 (2008$) for LHD and MHD 
trucks and $186 (2008$) for HHD trucks. These costs include a low 
complexity ICM of 1.14 and are applicable in the 2014 model year.
(iv) Reasonableness of the Proposed Standards
    The proposed 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.\187\ 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.\188\ 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 
proposed 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.
---------------------------------------------------------------------------

    \187\ See Section VIII.D.
    \188\ 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 proposing vehicle standards less stringent 
than the proposed standards because the agencies believe these 
standards are highly cost effective, as just explained.
    The agencies considered proposing 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 draft RIA at Chapter 6.1.8. The 
emission reductions associated with these very high costs appear to be 
modest. See the draft RIA Table 6-14. In addition, the agencies are 
proposing flexibilities in the form of generally applicable credit 
opportunities for advanced technologies, to encourage use of hybrid 
powertrains. See Section IV.C.2 below. The agencies welcome comments on 
whether hybrid powertrain technologies are appropriate to consider for 
the 2017 model year standard, or if not, then when would they be 
appropriate.
(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 0.2 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 
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% application 
rate of

[[Page 74246]]

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 propose that the gasoline engine standards 
begin in the 2016 model year based on the agencies' projection of the 
engine redesign schedules of the small number of engines in this 
category.
(iii) Gasoline Engine Technology Package Cost
    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 BOM approach employed by 
NHTSA and EPA in the 2012-2016 LD rule. NHTSA and EPA are proposing to 
use the marked up gasoline engine technology costs developed for the HD 
Pickup Truck and Van segment because they are made by the same 
manufacturers (primarily by Ford and GM) and, the same products simply 
sold as loose engines rather than complete vehicles. Hence the engine 
cost estimates are fundamentally the same. The costs are summarized in 
Table III-15. The costs shown in Table III-15 include a low complexity 
ICM of 1.17 and are applicable in the 2016 model year. No learning 
effects are applied to engine friction reduction costs, while time 
based learning is considered applicable to both coupled cam phasing and 
SGDI.
[GRAPHIC] [TIFF OMITTED] TP30NO10.041

(iv) Reasonableness of the Proposed Standard
    The proposed engine standards appear to be 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 proposal reflects 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-15. Use 
of these technologies would add only a small amount to the cost of the 
vehicle,\189\ and the associated reductions are highly cost effective, 
an estimated $30 per ton of CO2eq per vehicle.\190\ 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.\191\ 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).
---------------------------------------------------------------------------

    \189\ 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.
    \190\ See Vocational Vehicle CO2 savings and 
technology costs for Alternative 2 in Section IX.B.
    \191\ 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 Gasoline Engine Standards Considered
    The agencies are not proposing gasoline standards less stringent 
than the proposed standards because the agencies believe these 
standards are feasible in the lead time provided, inexpensive, and 
highly cost effective. We welcome comments supplemented with data on 
each aspect of this determination most importantly on individual 
gasoline engine technology efficacy to reduce fuel consumption and GHGs 
as well was our estimates of individual technology cost and lead-time.
    The proposed 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 proposing gasoline engine 
standards which are more stringent reflecting the inclusion of cylinder 
deactivation and other advanced technologies. However, the agencies are 
not proposing this level of stringency because our assessment is that 
these technologies would not be available for production by the 2017 
model year. The agencies welcome comments on whether other gasoline 
technologies are appropriate to consider for the 2017 model year 
standard, or if not, then when would they be appropriate.
(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 0.2 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 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 draft 
RIA Chapter 2.

[[Page 74247]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.042

(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 draft 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 proposed 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 
proposing set CO2 emission standards recognizing the 
opportunity for technology improvements over this timeframe while 
reflecting the typical heavy-duty engine manufacturer product plan 
cycles. Thus, the agencies are proposing to establish initial standards 
for the 2014 model year and a more stringent standard for 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 
plus turbocompounding. 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 draft RIA Chapter 2.4.2.13. The 
agencies used a 100 percent application rate of the technology package 
to determine the proposed 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.\192\ Therefore, 
these technologies were not included in determining the stringency of 
the proposed 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 proposing provisions described in Section IV to create 
incentives for manufacturers to continue to invest to develop this 
technology.
---------------------------------------------------------------------------

    \192\ 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.
[GRAPHIC] [TIFF OMITTED] TP30NO10.043

(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 proposal (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

[[Page 74248]]

appropriate when compliance with proposed 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 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 draft 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 $6,750,000 per manufacturer per year over the 
five years covering 2012 through 2016. In aggregate, this averages out 
to $280 per engine during 2012 through 2016 using a very rough annual 
sales value of 600,000 LHD, MHD and HHD diesel engines. The agencies 
also are estimating costs of $100,000 per engine manufacturer per 
engine class (LHD, MHD and HHD diesel) 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 $4 per engine in 2013 using a very 
rough annual sales value of 600,000 LHD, MHD and HHD diesel engines.
    EPA also developed the incremental piece cost for the components to 
meet each of the 2014 and 2017 standards. These costs shown in Table 
III-18 which include a low complexity ICM of 1.11; time based learning 
is considered applicable to each technology.

[[Page 74249]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.044

    The overall costs for each diesel engine regulatory subcategory are 
included in Table III-19.
[GRAPHIC] [TIFF OMITTED] TP30NO10.045

(iv) Reasonableness of the Proposed Standards
    The proposed 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 have already been demonstrated and their effectiveness is 
well documented. The proposal reflects 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-19. Use 
of these technologies would add only a small amount to the cost of the 
vehicle,\193\ and the associated reductions are highly cost effective, 
an estimated $30 per ton of CO2eq per vehicle.\194\ 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

[[Page 74250]]

the agencies to be a highly cost effective reduction.\195\ 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).
---------------------------------------------------------------------------

    \193\ 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.
    \194\ See Vocational Vehicle CO2 savings and 
technology costs for Alternative 2 in Section IX.B.
    \195\ 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 proposal related to legacy engine products, 
the agencies are not proposing diesel engine standards less stringent 
than the proposed standards because the agencies believe these 
standards are highly cost effective. We welcome comments supplemented 
with data on each aspect of this determination most importantly on 
individual engine technology efficacy to reduce fuel consumption and 
GHGs as well as our estimates of individual technology cost and lead-
time.
    The agencies considered proposing diesel engine standards which are 
more stringent reflecting the inclusion of other advanced technologies. 
However, the agencies are not proposing this level of stringency 
because our assessment is that these technologies would not be 
available for production by the 2017 model year. The agencies welcome 
comments on whether other diesel engine technologies are appropriate to 
consider for the 2017 model year standard, or if not, then when would 
they be appropriate.

IV. Proposed Regulatory Flexibility Provisions

    This section discusses proposed flexibility provisions intended to 
achieve the goals of the overall program while providing alternate 
pathways to achieve those goals. The primary flexibility provisions the 
agencies are proposing for combination tractors and vocational vehicles 
relate to a program of Averaging, Banking, and Trading of credits that 
EPA and NHTSA are proposing in association with each agency's 
respective CO2 and fuel consumption standards (see Section 
II above). For HD pickups and vans, the primary flexibility provision 
is the fleet averaging program patterned after the LD GHG and CAFE 
rule. EPA is not proposing an emission credit program associated with 
the proposed N2O, CH4, or HFC standards. This 
section also describes proposed flexibility provisions that would apply 
in specific circumstances.

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. ABT programs can be 
important because they can help to address many issues of technological 
feasibility and lead-time, as well as considerations of cost. ABT 
programs are not just add-on provisions included to help reduce costs, 
but are usually an integral part of the standard setting itself. An ABT 
program is important because it provides manufacturers flexibilities 
that assist the development and implementation of new technologies 
efficiently and therefore enables new technologies to be implemented at 
a more progressive pace than without ABT. A well-designed ABT program 
can provide important environmental benefits and at the same time 
increase flexibility for and reduce costs to the regulated industry.
    Section II above describes EPA's proposed GHG emission standards 
and NHTSA's proposed fuel consumption standards. For each of these 
respective sets of standards, the agencies are also proposing ABT 
provisions consistent with each agency's statutory authority. The 
agencies have worked closely together to design these proposed 
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 this proposed GHG 
ABT program for HD engines is based closely on earlier ABT programs for 
HD engines; the proposed program for HD pickups and vans is built on 
the existing light-duty GHG program flexibility provisions; and we 
propose first-time ABT provisions for combination tractors and 
vocational vehicles that are as consistent as possible with our other 
HD vehicle regulations. The flexibility provisions associated with this 
new regulatory category are intended to systematically build upon the 
structure of the existing programs.
    As an overview, ``averaging'' means the exchange of emission 
credits between engine families or truck families within a given 
manufacturer's regulatory subcategory. For example within each 
regulatory subcategory, engine manufacturers divide their product line 
into ``engine families'' that are comprised of engines expected to have 
similar emission characteristics throughout their useful life. 
Averaging allows a manufacturer to certify one or more engine families 
within the same regulatory subcategory at levels above the applicable 
emission standard. The increased emissions over the standard would need 
to be offset by one or more engine families within that manufacturer's 
regulatory subcategory that are certified below the same emission 
standard, such that the average emissions 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 standard. 
(The inclusion of engine power, useful life, and production volume in 
the averaging calculations allows the emissions credits or debits to be 
expressed in total emissions over the useful life of the credit-using 
or generating engine sales.) Total credits for each regulatory 
subcategory within each model year are determined by summing together 
the credits calculated for every engine family within that specific 
regulatory subcategory.
    ``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 the current HD program for criteria pollutants, manufacturers 
are restricted to only averaging, banking and trading credits generated 
within a regulatory subcategory, and we are proposing to continue this 
restriction in the GHG and fuel consumption program. However, the 
agencies are evaluating--and therefore request comment on--potential 
alternative approaches in which fewer restrictions are placed on the 
use of credits for averaging, banking, and trading. Particularly, the 
agencies request comment on removing prohibitions on averaging and 
trading between some or all regulatory categories in this 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).
    In the past, we have followed the practice of allowing averaging 
and trading between like products because we have recognized that the 
estimation of emissions credits is not an absolutely precise process, 
and actual emissions reductions or increases ``in use'' would vary due 
to differences in vehicle duty cycles, maintenance practices and any

[[Page 74251]]

number of other factors. By restricting credit averaging and trading to 
only allow averaging and trading between like products, the agencies 
gain some degree of assurance that the operation and use of the 
vehicles generating credits and consuming credits would be similar. The 
agencies also note that some industry participants have expressed 
concern that allowing credit averaging, banking and trading across 
different products may create an unlevel playing field for the 
regulated industry. Specifically, engine and truck manufacturers have 
commonly expressed to us a concern that some manufacturers with a wide 
range of product offerings spanning a number of regulatory categories 
would be able to use the ABT program provisions to generate credits in 
regulatory class markets where they face less competition and then use 
those credits to compete unfairly in other regulatory categories where 
they face greater competition. Finally, in the context of regulating 
criteria pollutants that can have localized and regional impacts, we 
have been concerned about the unintended consequence of unrestricted 
credit averaging or trading on local or regional concentrations of 
pollutants, whereby emissions reductions might become concentrated in 
some localities or regions to the detriment of other areas needing the 
reductions.
    The agencies are evaluating the possibility of placing fewer 
restrictions on averaging and trading because increasing the 
flexibility offered to manufacturers to average, bank, and trade 
credits across regulatory subcategories and categories could 
potentially significantly reduce the overall cost of the program. 
Specifically, we request comment on the extent to which a difference--
or unexpected difference--in the marginal costs of compliance per 
gallon of fuel saved or ton of GHG reduced across categories or 
subcategories, combined with provision for averaging and trading across 
categories and subcategories, can allow manufacturers to achieve the 
same overall reduction in fuel use and emissions at lower cost.
    While trading restrictions in the context of past EPA rulemakings 
have been motivated in part by the local or regional nature of the 
pollutant being regulated, in this instance, opportunities for greater 
flexibility may exist in light of the fact that greenhouse gases are a 
global pollutant for which local consequences are related to global, 
not local or regional atmospheric concentrations. However, trading 
ratios may need to be established for averaging and trading across 
categories, and potentially across subcategories, to ensure that 
averaging and trading across categories and subcategories does not lead 
to a net increase in emissions or fuel use in light of differences in 
vehicle use patterns across categories and subcategories. Further, it 
is possible to design trading ratios that ensure a net reduction in 
emissions and fuel use as a result of averaging and trading. The 
agencies also request comment on the potential additional savings in 
costs (beyond those already calculated in this proposal) due to 
increased flexibility in averaging and trading provisions, on how such 
averaging and trading flexibilities could be designed to ensure 
environmental neutrality, on whether trading ratios should be designed 
to achieve a net reduction in emissions and fuel use as a result of 
trading, on the concerns that have been raised by some regarding 
impacts on intra-industry competition, and on how to address the above 
identified concerns about dissimilarities in operation and use of 
vehicles.
(1) Heavy-duty Engines
    For the heavy-duty engine ABT program, EPA and NHTSA are proposing 
to use EPA's existing regulatory engine classifications as the 
subcategory designations under this engine ABT program. The proposed 
regulations use the term ``averaging set'' which aligns with the 
regulatory subcategories or regulatory class in the context that they 
define the same set of products. The existing diesel engine 
subcategories are light-heavy-duty (LHD), medium-heavy-duty (MHD), and 
heavy-heavy-duty (HHD). LHD diesel engines are primarily used in 
vehicles with a GVWR below 19,500 lb. Vehicle body types in this group 
might include any heavy-duty vehicle built for a light-duty truck 
chassis, van trucks, multi-stop vans, recreational vehicles, and some 
single axle straight trucks. Vehicles containing these engines would 
normally include personal transportation, light-load commercial hauling 
and delivery, passenger service, agriculture, and construction 
applications.
    MHD diesel engines are normally used in vehicles whose GVWR varies 
from 19,501-33,000 lb. Vehicles containing these engines typically 
include school buses, tandem axle straight trucks, city tractors, and a 
variety of special purpose vehicles such as small dump trucks, and 
trash compactor trucks. Normally the applications for these vehicles 
would include commercial short haul and intra-city delivery and pickup.
    HHD diesel engines are intended for use in vehicles which exceed 
33,000 lb GVWR. Vehicles containing engines of this type are normally 
tractors, trucks, and buses used in inter-city, long-haul applications. 
HHD engines are generally regarded as designed for rebuild and have a 
long useful life period. LHD and MHD engines are typically not intended 
for rebuild, though some MHD engines are designed for rebuild, and have 
a shorter useful life.
    Gasoline or spark ignited engines for heavy-duty vehicles fall into 
one separate regulatory subcategory. These engines are typically 
installed in trucks with a GVWR ranging from 8,500 pounds to 19,500 
pounds although they can be installed into trucks of any size.
    The compliance program we are proposing would adopt a slightly 
different method for generating a manufacturer's CO2 
emission and fuel consumption credit or deficit. The manufacturer's 
certification test result would serve as the basis for the generation 
of the manufacturer's Family Certification Level (FCL). The FCL is a 
new term we propose 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 
could define its FCL at any level at or above the certification test 
result. Credits for the ABT program would be generated when the FCL is 
compared to its CO2 and fuel consumption standard, as 
discussed in Section II. The credits earned in this section would be 
restricted to the engine subcategory and not tradable with other engine 
subcategories consistent with EPA's past practice for ABT programs as 
described previously. Credit calculation for the proposed Engine ABT 
and program would be generated, either positive or negative, according 
to Equation IV-1 and Equation IV-2:

Equation IV-1: Proposed HD Engine CO2 credit (deficit)

HD Engine CO2 credit (deficit) (metric tons) = (Std-FCL) x 
(CF) x (Volume) x (UL) x (10-6)

Where:

Std = the standard associated with the specific engine regulatory 
subcategory (g/bhp-hr)
FCL = Family Certification Level for the engine family
CF = a transient cycle conversion factor in bhp-hr/mile which is the 
integrated total cycle brake horsepower-hour divided by the 
equivalent mileage of the Heavy-duty FTP cycle. For gasoline heavy-
duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-
duty engines, the equivalent mileage is 6.5 miles. The agencies are 
proposing that the CF

[[Page 74252]]

determined by the Heavy-duty FTP cycle be used for engines 
certifying to the SET standard.
Volume = (projected or actual) production volume of the engine 
family
UL = useful life of the engine (miles)
10-6 converts the grams of CO2 to metric tons

Equation IV-2: Proposed HD Engine Fuel Consumption credit (deficit) in 
gallons

HD Engine Fuel Consumption credit (deficit) (gallons) = (Std - FCL) x 
(CF) x (Volume) x (UL) x 102

Where:

Std = the standard associated with the specific engine regulatory 
subcategory (gallon/100 bhp-hr)
FCL = Family Certification Level for the engine family (gallon/100 
bhp-hr)
CF = a transient cycle conversion factor in bhp-hr/mile which is the 
integrated total cycle brake horsepower-hour divided by the 
equivalent mileage of the Heavy-duty FTP cycle. For gasoline heavy-
duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-
duty engines, the equivalent mileage is 6.5 miles. The agencies are 
proposing that the CF determined by the Heavy-duty FTP cycle be used 
for engines certifying to the SET standard.
Volume = (projected or actual) production volume of the engine 
family
UL = useful life of the engine (miles)
102 = conversion to gallons

    To calculate credits or deficits, manufacturers would determine an 
FCL for each engine family they have designated for the ABT program. We 
have defined engine families in 40 CFR 1036.230 and manufacturers may 
designate how to group their engines for certification and compliance 
purposes. The FCL may be above (negative) or below (positive) its 
standard and would be used to establish the CO2 credits 
earned (or used) in Equation IV-1. The proposed CO2 and fuel 
consumption standards are associated with specific regulatory 
subcategories as described in Sections II.B and II.D (gasoline, light 
heavy-duty diesel, medium heavy-duty diesel, and heavy heavy-duty 
diesel). In the ABT program, engines certified with an FCL below the 
standard generate positive credits (g/bhp-hr and gal/100 bhp-hr). As 
discussed in Section II.B and II.D, engine families for which a 
manufacturer elects to use the alternative standard of a percent 
reduction from the engine family's 2011 MY baseline would be ineligible 
to either generate or use credits.
    The volume used in Equations IV-1 and IV-2 refers to the total 
number of eligible engines sold per family participating in the ABT 
program during that model year. The useful life values in Equation IV-1 
are proposed to be the same as the regulatory classifications 
previously used for the engine subcategories. Thus, the agencies 
propose that for LHD diesel engines and gasoline engines, the useful 
life values would be 110,000 miles; for MHD diesel engines, 185,000 
miles; and for HHD diesel engines, 435,000 miles.
    As noted above, credits generated by engine manufacturers under 
this ABT program would be restricted for use only within their engine 
subcategory based on performance against the standard as defined in 
Section II.B and II.D. Thus, LHD diesel engine manufacturers could only 
use their LHD diesel engine credits for averaging, banking and trading 
with LHD diesel engines, not with MHD diesel or HHD diesel engines. 
This limitation is consistent with ABT provisions in EPA's existing 
criteria pollutant program for engines and would help assure that 
credits earned to reduce GHG emissions and fuel consumption would be 
used to limit their growth and not circumvent the intent of the 
regulations. EPA and NHTSA are concerned that extending the use of 
credits beyond these designated subcategories could also create an 
advantage for large or integrated manufacturers that currently does not 
exist in the market. A manufacturer that produces both engines and 
heavy-duty highway vehicles could mix credits across engine and vehicle 
categories, shifting the burden between the sectors, not equally shared 
in either sector, to gain an advantage over competitors that are not 
integrated. Similarly, large volume manufacturers of engines can shift 
credits between heavy heavy-duty diesel engines and light heavy-duty 
diesel engines to gain an advantage in one subcategory over other 
manufacturers that may not have multiple engine offerings over several 
regulatory engine subcategories. Finally, relating credits between 
subcategories of engines could be problematic because of the 
differences in regulatory useful lives. The agencies want to avoid 
having credits from longer useful life categories flooding shorter 
useful life categories, adversely impacting compliance with the 
proposed CO2 and fuel consumption standards in the shorter 
useful life category. The agencies would like to ensure that this 
regulation reduces CO2 emissions and improves fuel 
consumption in each engine subcategory while not interfering with the 
ability of manufacturers to engage in free trade and competition. 
Limiting credit ABT to the regulatory subcategory and not between 
engines and vehicles would help prevent a competitive advantage due 
solely to the regulatory structure. Although the reasons for 
restricting engine credits to the same engine subcategory seem 
persuasive to us, the agencies welcome comments on the extension of 
credits beyond the limitations we are proposing.\196\
---------------------------------------------------------------------------

    \196\ These concerns were not present in the 2012-2016 MY light-
duty vehicle rule, where most manufacturers offer diverse product 
lines and there is not as much disparity among useful lives. That 
rule consequently does not restrict CO2 credit trading 
opportunities between light-duty vehicle sectors.
---------------------------------------------------------------------------

    Under previous ABT programs for other rulemakings, EPA has allowed 
manufacturers to carry forward deficits from engines for a set period 
of time. The agencies are proposing to allow manufacturers of engines 
to carry forward deficits for up to three years before reconciling the 
short-fall. However, manufacturers would need to use credits, once 
credits are generated, 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. We will accept comments on alternative approaches for 
reconciling deficit shortfalls in the engine category.
    As described in Section II above, EPA is proposing that a 
manufacturer may choose to comply with the N2O or 
CH4 cap standards using CO2 credits. A 
manufacturer choosing this option would convert its N2O or 
CH4 test results into CO2eq to determine the 
amount of CO2 credits required. This approach recognizes the 
inter-correlation of these elements in impacting global warming. This 
option does not apply to the NHTSA fuel consumption program. To account 
for the different global warming potential of these GHGs, EPA proposes 
that manufacturers determine the amount of CO2 credits 
required by multiplying the shortfall by the GWP. For example, a 
manufacturer would use 25 kg of positive CO2 credits to 
offset 1 kg of negative CH4 credits. Or a manufacturer would 
use 298 kg of positive CO2 credits to offset 1 kg of 
negative N2O credits. In general we do not expect 
manufacturers to use this provision. However, we are providing this 
alternative as a flexibility in the event an engine manufacturer has 
trouble meeting the CH4 and/or N2O emission caps. 
There are not ABT credits for performance that falls below the 
CH4 or N2O caps.
    Additional flexibilities for engines are discussed later in Section 
IV(B).

[[Page 74253]]

(2) Class 7 and 8 Combination Tractors
    In addition to the engine ABT program described above, the agencies 
are also proposing a vehicle ABT program to facilitate reductions in 
GHG emissions and fuel consumption based on combination tractor design 
changes and improvements. For this category, the structure of the 
proposed ABT program should create incentives for tractor manufacturers 
to advance new, clean technologies, or existing technologies earlier 
than they would otherwise.
    As explained in Sections II and III above, combination tractor 
manufacturers are divided into nine regulatory subcategories under 
these proposed rules, as shown in the following table:
[GRAPHIC] [TIFF OMITTED] TP30NO10.046

    The proposed regulations use the term ``averaging set'' which 
aligns with the regulatory subcategories or regulatory class in the 
context that they define the same set of products. Vehicle credits for 
tractors in these classifications would be earned on a g/ton-mile or 
gallon/1,000 ton-mile basis for tractors which are below the standard. 
Credits generated within regulatory subcategories would be tradable 
between truck manufacturers in that specific regulatory subcategory 
only. Credits would not be fungible between engine and vehicle 
regulatory categories. This is similar to the restrictions we have 
described above for engine manufacturers.
    This limitation would help ensure that credits earned to reduce GHG 
emissions and fuel consumption would be used to limit their growth and 
not circumvent the intent of our regulation. As with engine credits, we 
are concerned that extending the use of credits to be transferred or 
traded to other classes may create an advantage for large or integrated 
manufacturers that currently does not exist in the market. We would 
like to ensure that this regulation reduces the emission of 
CO2 and fuel consumption but does not effectively penalize 
non-integrated manufacturers and those with limited participation in 
the market. ABT provides manufacturers the flexilibility to deal with 
unforeseen shifts in the marketplace that affect sales volumes. This 
structure allows for a straightforward compliance program for each 
sector independently with aspects that are also independently 
quantifiable and verifiable. Credit calculation for the proposed Class 
7 and 8 tractor CO2 and fuel consumption credits would be 
generated, either positive or negative, according to Equation IV-3 and 
Equation IV-4:

Equation IV-3: The Proposed Class 7 and 8 Tractor CO2 Credit 
(Deficit)

Class 7 and 8 Tractor CO2 credit (deficit)(metric tons) = 
(Std-FEL) x (Payload Tons) x (Volume) x (UL) x (10-6)

Where:

Std = the standard associated with the specific tractor regulatory 
class (g/ton-mile)
Payload tons = the prescribed payload for each class in tons (12.5 
tons for Class 7 and 19 tons for Class 8)
FEL = Family Emission Limit for the tractor family which is equal to 
the output from GEM (g/ton-mile)
Volume = (projected or actual) production volume of the tractor 
family
UL = useful life of the tractor (435,000 miles for Class 8 and 
185,000 miles for Class 7)
10-6 converts the grams of CO2 to metric tons

Equation IV-4: Proposed Class 7 and 8 Tractor Fuel Consumption credit 
(deficit) in gallons:

Class 7 and 8 Tractor Fuel Consumption credit (deficit)(gallons) = 
(Std-FEL) x (Payload Tons) x (Volume) x (UL) x 103

Where:

Std = the standard associated with the specific tractor regulatory 
subcategory (gallons/1,000 ton-mile)
Payload tons = the prescribed payload for each class in tons (12.5 
tons for Class 7 and 19 tons for Class 8)
FEL = Family Emission Limit for the tractor family (gallons/1,000 
ton-mile)
Volume = (projected or actual) production volume of the tractor 
family
UL = useful life of the tractor (435,000 miles for Class 8 and 
185,000 miles for Class 7)
103 = conversion to gallons

    Similar to the proposed Heavy-duty Engine ABT program described in 
the previous section, we are proposing that tractor manufacturers would 
be able to carry forward credit deficits from their regulatory 
subcategories for three years before reconciling the shortfall. 
However, just as in the engine category, manufacturers would need to 
use credits once those credits have been generated to offset a 
shortfall before those credits can be banked or traded for additional 
model years. This restriction reduces the chance of tractor 
manufacturers passing forward deficits before reconciling their 
shortfalls and exhausting those credits before reconciling past 
deficits. Manufacturers of vehicles that generate a deficit at the end 
of the model year could carry that deficit forward for three years 
following the model year for which that deficit was generated. Deficits 
would need to be reconciled at the reporting dates for year three. We 
will accept comments on alternative approaches of reconciling deficit 
shortfalls.
    Additional flexibilities for Class 7 and 8 combination tractors are 
discussed later in Section IV.B.
(3) Class 2b-8 Vocational Vehicles
    Similar to the Class 7 and 8 combination tractor manufacturers, we 
are offering a limited ABT program for Class 2b-8 vocational chassis 
manufacturers. Vehicle credits would be generated for those 
manufacturers that introduce products into the market with rolling 
resistance improvements which are better than required to meet the 
proposed vehicle standards, The certification of the chassis would be 
based on the use of LRR tires. Credit calculation for the proposed 
Class 2b-8 vocational vehicle CO2 and fuel consumption 
credits (deficits) would be generated, either positive or negative, 
according to Equation IV-5 and Equation IV-6:

Equation IV-5: The proposed Vocational Vehicle CO2 vehicle 
credit (deficit)

Vocational Vehicle CO2 credit (deficit) (metric tons) = 
(Std-FEL) x

[[Page 74254]]

(Payload Tons) x (Sales Volume) x (UL) x (10-6)

Where:

Std = the standard associated with the specific vocational vehicle 
subcategory (g/ton-mile)
Payload tons = the prescribed payload for each subcategory in tons 
(2.85 tons for LHD, 5.6 tons for MHD, and 19 tons for HHD vehicles)
FEL = Family Emission Limit for the vehicle family (g/ton-mile)
Volume = (projected or actual) production volume of the vehicle 
family
UL = useful life of the vehicle (110,000 miles for LHD, 185,000 
miles for MHD, or 435,000 miles for HHD vehicles)
10-6 converts the grams of CO2 to metric tons

Equation IV-6: Proposed Vocational Vehicle Fuel Consumption credit 
(deficit) in gallons

Vocational Vehicle Fuel Consumption credit for (deficit) (gallons) = 
(Std-FEL) x (Payload Tons) x (Sales Volume) x (UL) x 103

Where:

Std = the standard associated with the specific vocational vehicle 
regulatory subcategory (gallon/1,000 ton-mile)
Payload tons = the prescribed payload for each regulatory 
subcategory in tons (2.85 tons for LHD, 5.6 tons for MHD, and 19 
tons for HHD vehicles)
FEL = Family Emission Limit for the vehicle family (gallon/1,000 
ton-mile)
Volume = (projected or actual) production volume of the vehicle 
family
UL = useful life of the vehicle (110,000 miles for LHD, 185,000 
miles for MHD, or 435,000 miles for HHD vehicles)
10\3\ converts to gallons

    Also, similar to the proposed heavy-duty engine and tractor ABT 
programs, the vehicle credits generated within each regulatory 
subcategory would be allowed to be averaged, banked, or traded between 
chassis manufacturers within their existing subcategories. For 
vocational vehicles the proposed vehicle subcategories are based on the 
vehicle's GVWR. We are proposing three vehicle subcategories LHD with a 
GVWR less than or equal to 19,500 pounds, MHD vehicles with a GVWR 
greater than 19,500 and less than or equal to 33,000 pounds, and HHD 
vehicles with a GVWR greater than 33,000 pounds. These three weight 
categories would form the subcategories for vocational vehicles and are 
found in 40 CFR 1037.230. The proposed regulations use the term 
``averaging set'' which aligns with the regulatory categories or 
regulatory class in the context that they define the same set of 
products.
    Similar to the proposed Heavy-duty Engine ABT program above, 
vocational chassis manufacturers would be able to carry forward 
deficits for three years before reconciling the shortfall. However, 
just as in the engine category, manufacturers would need to use credits 
earned once those credits have been generated to offset a shortfall 
before those credits can be banked or traded for additional model 
years. This restriction reduces the chance of chassis manufacturers 
passing forward deficits before reconciling their shortfalls and 
exhausting those credits before reconciling past deficits. 
Manufacturers of vocational vehicles that generate a deficit at the end 
of the model year could carry that deficit forward for three years 
following the model year for which that deficit was generated. Deficits 
would need to be reconciled at the reporting dates for year three. We 
will accept comments on alternative approaches of reconciling deficit 
shortfalls.
(4) Heavy-Duty Pickup Truck and Van Flexibility Provisions
    EPA and NHTSA are proposing specific flexibility provisions for 
manufacturers of HD pickups and vans, similar to provisions adopted in 
the recent rulemaking for light-duty car and truck GHGs and fuel 
economy. Additional flexibilities that apply to the broad range of 
heavy-duty vehicles, including HD pickups and vans, are discussed in 
Section IV.B. All of these flexibilities would help enable new 
technologies to be implemented faster and more cost-effectively than 
without a flexibility program, and also help manufacturers deal with 
unexpected shifts in sales.
    A manufacturer's credit or debit balance would be determined by 
calculating their fleet average performance and comparing it to the 
manufacturer's CO2 and fuel consumption standards, as 
determined by their fleet mix, for a given model year. A target 
standard is determined for each vehicle with a unique payload, towing 
capacity and drive configuration. These unique targets, weighted by 
their associated production volumes, are summed at the end of the model 
year to derive the production volume-weighted manufacturer annual fleet 
average standard. A manufacturer would generate credits if its fleet 
average CO2 or fuel consumption level is lower than its 
standard and would generate debits if its fleet average CO2 
or fuel consumption level is above that standard. The end-of-year 
reports would provide appropriate data to reconcile pre-compliance 
estimates with final model year figures. Similar to the light-duty GHG 
program, the agencies would address any ultimate deficits by a possible 
void of certificates on a sufficient number of vehicles to address the 
shortfall. Enforcement action would entail penalty or other relief as 
appropriate or applicable.
    In addition to production weighting, we are proposing that the EPA 
credit calculations include a factor for the vehicle useful life, in 
miles, in order to allow the expression of credits in metric tons, as 
in the light-duty GHG program. The NHTSA credit calculation would use 
standard and performance levels in fuel consumption units (gallons per 
100 miles), as opposed to fuel economy units (mpg) as done in the 
light-duty program, along with the vehicle useful life, in miles, 
allowing the expression of credits in gallons. We propose that other 
provisions for the generation, tracking, trading, and use of the 
credits be the same as those adopted in the light-duty GHG program, 
including a 5-year limit on credit carry-forward to future model years 
and a 3-year limit on deficit carry-forward (or credit carry-back).
    The total model year fleet credit (debit) calculations would use 
the following equations:
CO2 Credits (Mg) = [(CO2 Std-CO2 Act) 
x Volume x UL] / 1,000,000
Fuel Consumption Credits (gallons) = (FC Std-FC Act) x Volume x UL x 
100

Where:

CO2 Std = Fleet average CO2 standard (g/mi)
FC Std = Fleet average fuel consumption standard (gal/100 mile)
CO2 Act = Fleet average actual CO2 value (g/
mi)
FC Act = Fleet average actual fuel consumption value (gal/100 mile)
Volume = the total production of vehicles in the regulatory class
UL = the useful life for the regulatory class (miles)

    We are proposing that HD pickups and vans comprise a self-contained 
averaging set, such that credits earned may be used freely for other HD 
pickups and vans but not for other vehicles or engines, and credits 
generated by other vehicles or engines may not be used to demonstrate 
compliance for HD pickups and vans. We believe this approach is 
appropriate because the HD pickup and van fleet is relatively small and 
the balanced fleetwide averaging concept is critical for obtaining the 
desired technology development in the 2014-2018 timeframe, so that the 
potential for large credit flows into or out of this vehicle category 
would create unwarranted market uncertainty, which in turn could 
jeopardize the impetus to develop needed technologies. An exception to 
this approach is proposed for advanced technology credits as discussed 
in Section IV.B(2).

[[Page 74255]]

    As described above, HD pickup and van manufacturers would be able 
to carry forward deficits from their fleet-wide average for three years 
before reconciling the shortfall. Manufacturers would be required to 
provide a plan in their pre-model year reports showing how they would 
resolve projected credit deficits. However, just as in the engine 
category, manufacturers would need to use credits earned once those 
credits have been generated to offset a shortfall before those credits 
can be banked or traded for additional model years. This restriction 
reduces the chance of vehicle manufacturers passing forward deficits 
before reconciling their shortfalls and exhausting those credits before 
reconciling past deficits. We request comments on all aspects of the 
proposed HD pickup and van credit program.

B. Additional Proposed Flexibility Provisions

    The agencies are also proposing provisions to facilitate reductions 
in GHG emissions and fuel consumption beginning in the 2014 model year. 
While we view our proposed ABT and flexibility structure as sufficient 
to encourage reduction efforts by heavy-duty highway engine and vehicle 
manufacturers, we understand that other efforts may enhance the overall 
GHG and fuel consumption reduction we anticipate achieving. Therefore 
we propose the following flexibilities to create additional 
opportunities for manufacturers to reduce their GHG emissions and fuel 
consumption. These opportunities would help provide additional 
incentives for manufacturers to innovate and to develop new strategies 
and cleaner technologies.
(1) Early Credit Option
    The agencies are proposing that manufacturers of HD engines, 
combination tractors, and vocational vehicles be eligible to generate 
early credits if they demonstrate improvements in excess of the 
proposed standards prior to model year they become effective. The start 
dates for EPA's GHG standards and NHTSA's fuel consumption standards 
vary by regulatory category (see Section II for the model years when 
the standards become effective). Specifically, manufacturers would need 
to certify their engines or vehicles to the standards at least six 
months before the start of the first model year of the mandatory 
standards. The limitations on the use of credits in the ABT programs--
i.e., limiting averaging to within each the regulatory category and 
vehicle or engine subcategory--would apply for the proposed early 
credits as well.
    NHTSA and EPA also request comment on whether a credit multiplier, 
specifically a multiplier of 1.5, would be appropriate to apply to 
early credits from HD engines, combination tractors, and vocational 
vehicles, as a greater incentive for early compliance. Additionally, 
the agencies seek comment on whether or not a requirement that HD 
engines, combination tractors, and vocational vehicles that are 
eligible to generate early credits, be allowed to do so only if they 
certify prior to June 1, 2013 should a multiplier of 1.5 be applied to 
early credits.
    We are proposing that manufacturers of HD pickups and vans who 
demonstrate improvements for model year 2013 such that their fleet 
average emissions and fuel consumption are lower than the model year 
2014 standards be eligible for early credits. Under the proposed 
structure for the fleet average standards, this credit opportunity 
would entail certifying a manufacturer's entire HD pickup and van fleet 
in model year 2013, and assessing this fleet against the model year 
2014 target levels discussed in Section II. The agencies consider the 
proposed availability of early credits to be a valuable complement to 
the overall program to the extent that they encourage early 
implementation of effective technologies. We request comment on ways 
the early credit opportunities can be tailored to accomplish this 
objective and protect against unanticipated windfalls.
(2) Advanced Technology Credits
    EPA and NHTSA are proposing targeted provisions that we expect 
would promote the implementation of advanced technologies. 
Specifically, manufacturers that incorporate these technologies would 
be eligible for special credits that could be applied to other heavy-
duty vehicles or engines, including those in other heavy-duty 
categories. We seek comment on any conversion factors that may be 
needed. Technologies that we propose to make eligible are:
     Hybrid powertrain designs that include energy storage 
systems.
     Rankine cycle engines.
     All-electric vehicles.
     Fuel cell vehicles.
    NHTSA and EPA request comment on whether a credit multiplier, 
specifically a multiplier of 1.5, would be appropriate to apply to 
advanced technology credits, as a greater incentive for their 
introduction. NHTSA and EPA request comment on the list of technologies 
identified as advanced technologies and whether additional technologies 
should be added to the list. NHTSA and EPA also request comment on 
whether credits generated from vehicles complying prior to 2014 and 
using Advanced SmartWay or Advanced SmartWay II aerodynamic 
technologies should be designated as Advanced Technology Credits.
(a) All-Electric Vehicles and HD Pickup Truck and Van Hybrids
    For HD pickup and van hybrids, we propose that testing would be 
done using adjustments to the test procedures developed for light-duty 
hybrids. NHTSA and EPA are also proposing that all-electric and other 
zero emission vehicles produced in model years before 2014 be able to 
earn credits for use in the 2014 and later HD pickup and van compliance 
program, provided the vehicles are covered by an EPA certificate of 
conformity for criteria pollutants. These credits would be calculated 
based on the 2014 diesel standard targets corresponding to the 
vehicle's work factor, and treated as though they were earned in 2014 
for purposes of credit life. Manufacturers would not have to early-
certify their entire HD pickup and van fleet in a model year as for 
other early-complying vehicles. NHTSA and EPA are also proposing that 
model year 2014 and later EVs and other zero emission vehicles be 
factored into the fleet average GHG and fuel consumption calculations 
based on the diesel standards targets for their model year and work 
factor. If advanced technology credits generated by pickups and vans 
are used in another HD vehicle category, these credits would, of 
course, be subtracted from the manufacturer's pickup and van category 
credit balance.
    In the 2012-2016 MY Light-Duty Vehicle Rule, EPA discussed at 
length the issue of whether to account for upstream emissions of GHGs 
in assessing the amount of credit to offer to various types of electric 
vehicles--that is, GHG emissions associated with generation of the 
electricity needed to power the electric vehicle. See 75 FR 25434-
25436. Although acknowledging that such emissions would not be 
accounted for if electric vehicle GHG emissions are assessed at zero 
for credit generating purposes, EPA believed that this was the 
appropriate course in order to provide an incentive for 
commercialization of this extremely promising technology. At the same 
time, EPA adopted a cumulative cap whereby upstream emissions would be 
accounted for if sales of EVs exceeded a given amount.

[[Page 74256]]

    The agencies believe that these same considerations apply to heavy-
duty vehicles. Indeed, the agencies believe that introduction of EVs 
into the heavy-duty fleet would be less frequent than for light-duty 
vehicles, so that there is less risk of dilution of the main standards 
by unexpectedly high introduction of EVs into the heavy-duty fleet and 
at least an equally compelling reason to provide an incentive for the 
technology's commercial introduction. Given the unlikelihood of 
significant penetration of the technology in the model years of these 
standards, the agencies similarly do not see a need to adopt the type 
of cumulative caps which would trigger an upstream emission accounting 
procedure as in the light-duty vehicle rule. The agencies solicit 
comment on these issues, however.
(b) Vocational Vehicle and Tractor Hybrids
    For vocational vehicles or combination tractors incorporating 
hybrid powertrains, we propose two methods for establishing the number 
of credits generated, each of which is discussed next. The agencies are 
not aware of models that have been adequately peer reviewed with data 
that can assess this technology without the conclusion of a comparison 
test of the actual physical product.
(i) Chassis Dynamometer Evaluation
    For hybrid certification to generate credits we propose to utilize 
chassis testing as an effective way to compare the CO2 
emissions and fuel consumption performance of conventional and hybrid 
vehicles. We are proposing that heavy-duty hybrid vehicles be certified 
using ``A to B'' vehicle chassis dynamometer testing. This concept 
allows a hybrid vocational vehicle manufacturer to directly quantify 
the benefit associated with use of its hybrid system on an application-
specific basis. The concept would entail testing the conventional 
vehicle, identified as ``A'', using the cycles as defined in Section V. 
The ``B'' vehicle would be the hybrid version of vehicle ``A''. The 
``B'' vehicle would need to be the same exact vehicle model as the 
``A'' vehicle. As an alternative, if no specific ``A'' vehicle exists 
for the hybrid vehicle that is the exact vehicle model, the most 
similar vehicle model would need to be used for testing. We propose to 
define the ``most similar vehicle'' as a vehicle with the same 
footprint, same payload, same testing capacity, the same engine power 
system, the same intended service class, and the same coefficient of 
drag.
    To determine the benefit associated with the hybrid system for GHG 
performance, the weighted CO2 emissions results from the 
chassis test of each vehicle would define the benefit as described 
below:

1. (CO2--A-CO2--B)/(CO2--A) = -------- 
(Improvement Factor)
2. Improvement Factor x GEM CO2 Result--B = -------- (g/ton 
mile benefit)

    Similarly, the benefit associated with the hybrid system for fuel 
consumption would be determined from the weighted fuel consumption 
results from the chassis tests of each vehicle as described below:

3. (Fuel Consumption--A-Fuel Consumption--B)/(Fuel Consumption--A) = --
------ (Improvement Factor)
4. Improvement Factor x GEM Fuel Consumption Result--B = -------- 
(gallon/1,000 ton mile benefit)

    The credits for the hybrid vehicle would be calculated as described 
in the ABT program by Equation IV-5 and Equation IV-6, except that the 
result from Equation 2 above replaces the (Std-FEL) value. We are 
proposing that the tons of CO2 or gallons of fuel credits 
generated by a hybrid vehicle could flow into any regulatory 
subcategory.
    The agencies are proposing two sets of duty cycles to evaluate the 
benefit depending on the vehicle application to assess hybrid vehicle 
performance--without and with PTO systems. The key difference between 
these two sets of vehicles is that one set (e.g., delivery trucks) does 
not operate a PTO while the other set (e.g., bucket and refuse trucks) 
does.
    The first set of duty cycles would apply to the hybrid powertrains 
used to improve the motive performance of the vehicles without a PTO 
system (such as pickup and delivery trucks). The typical operation of 
these vehicles is very similar to the overall drive cycles proposed in 
Section II. Therefore, the agencies are proposing to use the same 
vehicle drive cycle weightings for testing these vehicles, as shown in 
Table IV-2.
[GRAPHIC] [TIFF OMITTED] TP30NO10.047

    The second set of duty cycles apply to testing hybrid vehicles used 
in applications such as utility and refuse trucks tend to have 
additional benefits associated with use of stored energy, which avoids 
main engine operation and related CO2 emissions and fuel 
consumption during PTO operation. To appropriately address benefits, 
exercising the conventional and hybrid vehicles using their PTO would 
help to quantify the benefit to GHG emissions and fuel consumption 
reductions. The duty cycle proposed to quantify the hybrid 
CO2 and fuel consumption impact over this broader set of 
operation would be the three primary drive cycles plus a PTO duty 
cycle. Our proposed PTO cycle is based on consideration of using 
alternate, appropriate duty cycles with Administrator approval in a 
public process. The PTO duty cycle as proposed takes into account the 
sales impact and population of utility trucks and refuse haulers. As 
described in draft RIA Chapter 3, the agencies are proposing to add an 
additional PTO cycle to measure the improvement achieved for this type 
of hybrid powertrain application. The proposed weightings for the 
hybrids with PTO are included in Table IV-3. The agencies welcome 
comments on the proposed drive cycle weightings and the proposed PTO 
cycle.

[[Page 74257]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.048

(ii) Engine Dynamometer Evaluation
    The engine test procedure we are proposing for hybrid evaluation 
involves exercising the conventional engine and hybrid-engine system 
based on an engine testing strategy. The basis for the system control 
volume, which serves to determine the valid test article, would need to 
be the most accurate representation of real world functionality. An 
engine test methodology would be considered valid to the extent the 
test is performed on a test article that does not mischaracterize 
criteria pollutant performance or actual system performance. Energy 
inputs should not be based on simulation data which is not an accurate 
reflection of actual real world operation. It is clearly important to 
be sure credits are generated based on known physical systems. This 
includes testing using recovered vehicle kinetic energy. Additionally, 
the duty cycle over which this engine-hybrid system would be exercised 
would need to reflect the use of the application, while not promoting a 
proliferation of duty cycles which prevent a standardized basis for 
comparing hybrid system performance. The agencies are proposing the use 
of the Heavy-duty FTP cycle for evaluation of hybrid vehicles, which is 
the same test cycle proposed for engines used in vocational vehicles. 
For powerpack testing, which includes the engine and hybrid systems in 
a pre-transmission format, the engine based testing is applicable for 
determination of brake-specific emissions benefit versus the engine 
standard. For post-transmission powertrain systems and vehicles, the 
comparison evaluation based on the Improvement Factor and the GEM 
result based on a vehicle drive trace in a powertrain test cell or 
chassis dynamometer test cell seem to accurately reflect the 
performance improvements associated with these test configurations. It 
is important that introduction of clean technology be incentivized 
without compromising the program intent of real world improvements in 
GHG and fuel consumption performance. The agencies seek comments on the 
most appropriate test procedures to accurately reflect the performance 
improvement associated with hybrid systems tested using these or other 
protocols.
(3) Innovative Technology Credits
    NHTSA and EPA are proposing a credit opportunity intended to apply 
to new and innovative technologies that reduce fuel consumption and 
CO2 emissions, but for which the reduction benefits are not 
captured over the test procedure used to determine compliance with the 
standards (i.e., the benefits are ``off-cycle''). See 75 FR 25438-25440 
where EPA adopted a similar credit program for MY 2012-2016 light-duty 
vehicles. In this case, the `test procedure' includes not only the 
Heavy-duty FTP and SET procedures used to measure compliance with the 
engine standards, but also the GEM. Eligible innovative technologies 
would be those that are newly introduced in one or more vehicle models 
or engines, but that are not yet widely implemented in the heavy-duty 
fleet. This could include known technologies not yet widely utilized in 
a particular subcategory. Further, any credits for these off-cycle 
technologies would need to be based on real-world fuel consumption and 
GHG reductions that can be measured with verifiable test methods and 
representing driving conditions typical of the vehicle application.
    We would not consider technologies to be eligible for these credits 
if the technology has a significant impact on CO2 emissions 
and fuel consumption over the primary test cycles or are the 
technologies on whose performance the various vehicle and engine 
standards are premised. However, EPA and NHTSA are aware of some 
emerging and innovative technologies and concepts in various stages of 
development with CO2 emissions and fuel consumption 
reduction potential that might not be adequately captured on the 
proposed certification test cycles, and we believe that some of these 
technologies might merit some additional CO2 and fuel 
consumption credit generating potential for the manufacturer. Examples 
include predictive cruise control, gear-down protection, and active 
aerodynamic features not exercised in the certification test, such as 
adjustable ride height for pickup trucks. We believe it would be 
appropriate to provide an incentive to encourage the introduction of 
these types of technologies and that a credit mechanism is an effective 
way to do so. This optional credit opportunity would be available 
through the 2018 model year reflecting that technologies may be common 
by then, but the agencies welcome comment on the need to extend beyond 
model year 2018.
    EPA and NHTSA propose that credits generated using innovative 
technologies be restricted within the subcategory where the credit was 
generated. The agencies request comments whether credits generated 
using innovative technologies should be fungible across vehicle and 
engine categories.
    We are proposing that manufacturers quantify CO2 and 
fuel consumption reductions associated with the use of the off-cycle 
technologies such that the credits could be applied based on the 
proposed metrics (such as g/mile and gal/100 mile for pickup trucks, g/
ton-mile and gal/1,000 ton-mile for tractors and vocational vehicles, 
and g/bhp-hr and gal/100 bhp-hr for engines). Credits would have to be 
based on real additional reductions of CO2 emissions and 
fuel consumption and would need to be quantifiable and verifiable with 
a repeatable methodology. Such submissions of data should be submitted 
to EPA and NHTSA, and would be subject to a public evaluation process 
in which the public would have opportunity for comment. See 75 FR 
25440. We propose that the technologies upon which the credits are 
based would be subject to full useful life compliance provisions, as 
with other emissions controls. Unless the manufacturer can demonstrate 
that the technology would not be subject to in-use deterioration over 
the useful life of the vehicle, the manufacturer would have to account 
for deterioration in the estimation of the credits in order to ensure 
that the credits are based on real in-use emissions reductions over the 
life of the vehicle.
    In cases where the benefit of a technological approach to reducing 
CO2 emissions and fuel consumption cannot be adequately 
represented using existing test cycles, EPA and NHTSA would review and 
approve as appropriate test procedures and analytical approaches to 
estimate the effectiveness of the technology for the purpose of 
generating credits. The demonstration program should be robust, 
verifiable, and capable of demonstrating the real-world emissions 
benefit of the technology with strong statistical significance. See 75 
FR

[[Page 74258]]

25440. For HD pickups and vans, EPA and NHTSA believe that the 5-cycle 
approach currently used in EPA's fuel economy labeling program for 
light-duty vehicles may provide a suitable test regimen, provided it 
can be reliably conducted on the dynamometer and can capture the impact 
of the off-cycle technology (see 71 FR 77872, December 27, 2006). EPA 
established the 5-cycle test methods to better represent real-world 
factors impacting fuel economy, including higher speeds and more 
aggressive driving, colder temperature operation, and the use of air 
conditioning.
    The CO2 and fuel consumption benefit of some 
technologies may be able to be demonstrated with a modeling approach. 
In other cases manufacturers might have to design on-road test programs 
that are statistically robust and based on real-world driving 
conditions. Whether the approach involves on-road testing, modeling, or 
some other analytical approach, the manufacturer would be required to 
present a proposed methodology to EPA and NHTSA. EPA and NHTSA would 
approve the methodology and credits only if certain criteria were met. 
Baseline emissions and control emissions would need to be clearly 
demonstrated over a wide range of real-world driving conditions and 
over a sufficient number of vehicles to address issues of uncertainty 
with the data. Data would need to be on a vehicle model-specific basis 
unless a manufacturer demonstrated model-specific data was not 
necessary. Approval of the approach to determining a CO2 and 
fuel consumption benefit would not imply approval of the results of the 
program or methodology; when the testing, modeling, or analyses are 
complete the results would likewise be subject to EPA and NHTSA review 
and approval. The agencies believe that suppliers and vehicle 
manufacturers could work together to develop testing, modeling, or 
analytical methods for certain technologies, similar to the SAE 
approach used for A/C refrigerant leakage scores. As with the similar 
procedure for alternative off-cycle credits under the 2012-2016 MY 
light-duty vehicle program, the agencies would include an opportunity 
for public comment as part of any approval process.
    The agencies request comments on the proposed approach for off-
cycle emissions credits, including comments on how best to structure 
the program. EPA and NHTSA particularly request comments on how the 
case-by-case approach to assessing off-cycle innovative technology 
credits could best be designed, including ways to ensure the 
verification of real-world emissions benefits and to ensure 
transparency in the process of reviewing manufacturers' proposed test 
methods.

V. NHTSA and EPA Proposed Compliance, Certification, and Enforcement 
Provisions

A. Overview

(1) Proposed Compliance Approach
    This section describes EPA's and NHTSA's proposed program to ensure 
compliance with EPA's proposed emission standards for CO2, 
N2O, and CH4 and NHTSA's proposed fuel 
consumption standards, as described in Section II. To achieve the goals 
projected in this proposal, it is important for the agencies to have an 
effective and coordinated compliance program for our respective 
standards. As is the case with the Light-Duty GHG and CAFE program, the 
proposed compliance program for heavy-duty vehicles and engines has two 
central priorities. (1) To address the agencies' respective statutory 
requirements; and (2) to streamline the compliance process for both 
manufacturers and the agencies by building on existing practice 
wherever possible, and by structuring the program such that 
manufacturers can use a single data set to satisfy the requirements of 
both agencies. It is also important to consider the provisions of EPA's 
existing criteria pollutant program in the development of the approach 
used for heavy-duty certification and compliance. The existing EPA 
heavy-duty highway engine emissions program has an established 
infrastructure and methodology that would allow effective integration 
with this proposed GHG and fuel consumption program, without needing to 
create new unique processes in many instances. The compliance program 
would also need to address the importance of the impact of new control 
methods for heavy-duty vehicles as well as other control systems and 
strategies that may extend beyond the traditional purview of the 
criteria pollutant program.
    The proposed heavy-duty compliance program would use a variety of 
mechanisms to conduct compliance assessments, including preproduction 
certification and postproduction, in-use monitoring once vehicles enter 
customer service. Specifically, the agencies are establishing a 
compliance program that utilizes existing EPA testing protocols and 
certification procedures. Under the provisions of this program, 
manufacturers would have significant opportunity to exercise 
implementation flexibility, based on the program schedule and design, 
as well as the credit provisions that are being proposed in the program 
for advanced technologies. This proposal includes a process to foster 
the use of innovative technologies, not yet contemplated in the current 
certification process. EPA would continue to conduct compliance preview 
meetings which provide the agency an opportunity to review a 
manufacturer's new product plans and ABT projections. Given the nature 
of the proposed compliance program which would involve both engine and 
vehicle compliance for some categories, it would be necessary for 
manufacturers to begin pre-certification meetings with EPA early enough 
to address issues of certification and compliance for both integrated 
and non-integrated product offerings.
    Based on feedback EPA and NHTSA received during the Light-Duty GHG 
comment period, both agencies would seek to ensure transparency in the 
compliance process. In addition to providing information in published 
reports annually regarding the status of credit balances and compliance 
on an industry basis, EPA and NHTSA seek comment on additional 
strategies for providing information useful to the public regarding 
industry's progress toward reducing GHG emissions and fuel consumption 
from this sector while protecting sensitive business information.
(a) Heavy-Duty Pickup Trucks and Vans
    The proposed compliance regulations (for certification, testing, 
reporting, and associated compliance activities) for heavy-duty pickup 
trucks and vans closely track both current practices and the recently 
adopted greenhouse gas regulations for light-duty vehicles and trucks. 
Thus they would be familiar to manufacturers. EPA already oversees 
testing, collects and processes test data, and performs calculations to 
determine compliance with both CAFE and CAA standards for Light-Duty. 
For Heavy-Duty products that closely parallel light-duty pick-ups and 
vans, under a coordinated approach, the compliance mechanisms for both 
programs for NHTSA and EPA would be consistent and non-duplicative for 
GHG pollutant standards and fuel consumption requirements. Vehicle 
emission standards established under the CAA apply throughout a 
vehicle's full useful life.
    Under EPA existing criteria pollutant emission standard program for 
heavy-duty pickup trucks and vans, vehicle manufacturers certify a 
group of vehicles called a test group. A test group

[[Page 74259]]

typically includes multiple vehicle lines and model types that share 
critical emissions-related features. The manufacturer generally selects 
and tests a single vehicle, typically considered ``worst case'' for 
criteria pollutant emissions, which is allowed to represent the entire 
test group for certification purposes. The test vehicle is the one 
expected to be the worst case for the emission standard at issue. 
Emissions from the test vehicle are assigned as the value for the 
entire test group. However, the compliance program in the recent GHG 
regulations for light-duty vehicles, which is essentially the well 
established CAFE compliance program, allows and may require 
manufacturers to perform additional testing at finer levels of vehicle 
models and configurations in order to get more precise model-level fuel 
economy and CO2 emission levels. This same approach would be 
applied to heavy-duty pickups and vans. Additionally, like the light-
duty program, approved use of analytically derived fuel economy would 
be allowed to predict the fuel efficiency and CO2 levels of 
some vehicles in lieu of testing when deemed appropriate by the 
agencies. The degree to which analytically derived fuel economy would 
be allowed and the design of the adjustment factors would be determined 
by the agencies.
(b) Heavy-Duty Engines
    Heavy-duty engine certification and compliance for traditional 
criteria pollutants has been established by EPA in its current general 
form since 1985. In developing a program to address GHG pollutants, it 
is important to build upon the infrastructure for certification and 
compliance that exists today. At the same time, it is necessary to 
develop additional tools to address compliance with GHG emissions 
requirements, since the proposed standard reflect control strategies 
that extend beyond those of traditional criteria pollutants. In so 
doing, the agencies are proposing use of EPA's current engine test 
based strategy--currently used for criteria pollutant compliance--to 
also measure compliance for GHG emissions. The agencies are also 
proposing to add new strategies to address vehicle specific designs and 
hardware which impact GHG emissions. The traditional engine approach 
would largely match the existing criteria pollutant control strategy. 
This would allow the basic tools for certification and compliance, 
which have already been developed and implemented, to be expanded for 
carbon dioxide, methane, and nitrous oxide. Engines with similar 
emissions control technology may be certified in engine families, as 
with criteria pollutants.
    For EPA, the proposed approach for certification would follow the 
current process, which would require manufacturer submission of 
certification applications, approval of the application, and receipt of 
the certificate of conformity prior to introduction into commerce of 
any engines. EPA proposes the certificate of conformity be a single 
document that would be applicable for both criteria pollutants and 
greenhouse gas pollutants. NHTSA would assess compliance with its fuel 
consumption standards based on the results of the EPA GHG emissions 
compliance process for each engine family.
(c) Class 7 and 8 Combination Tractors and Class 2b-8 Vocational 
Vehicles
    Currently, except for HD pickups and vans, EPA does not directly 
regulate exhaust emissions from heavy-duty vehicles as a complete 
entity. Instead, a compliance assessment of the engine is undertaken as 
described above. Vehicle manufacturers installing certified engines are 
required to do so in a manner that maintains all functionality of the 
emission control system. While no process exists for certifying these 
heavy-duty vehicles, the agencies believe that a process similar to the 
one we propose for use for heavy-duty engines can be applied to the 
vehicles.
    The agencies are proposing related certification programs for 
heavy-duty vehicles. Manufacturers would divide their vehicles into 
families and submit applications to each agency for certification for 
each family. However, the demonstration of compliance would not require 
emission testing of the complete vehicle, but would instead involve a 
computer simulation model, GEM. This modeling tool uses a combination 
of manufacturer-specified and agency-defined vehicle parameters to 
estimate vehicle emissions and fuel consumption. This model would then 
be exercised over certain drive cycles. EPA and NHTSA are proposing the 
duty cycles over which Class 7 and 8 combination tractors would be 
exercised to be: 65 mile per hour steady state cruise cycle, the 55 
mile per hour steady state cruise cycle, and the California ARB 
transient cycle. Additional details regarding these duty cycles will be 
addressed in Section V.D(1)(b) below. Over each duty cycle, the 
simulation tool would return the expected CO2 emissions, in 
g/ton-mile, and fuel consumption, gal/1,000 ton-mile, which would then 
be compared to the standards.

B. Heavy-Duty Pickup Trucks and Vans

(1) Proposed Compliance Approach
    EPA and NHTSA are proposing new emission standards to control 
greenhouse gases (GHGs) and reduce fuel consumption from heavy-duty 
trucks between a gross vehicle weight rating between 8,500 and 14,000 
pounds that are not already covered under the MY 2012-2016 light-duty 
truck and medium-duty passenger vehicle GHG standards. In this section 
``trucks'' now refers to heavy-duty pickup trucks and vans between 
8,500 and 14,000 pounds not already covered under the above light-duty 
rule.
    First, EPA is proposing fleet average emission standards for 
CO2 on a gram per mile (g/mile) basis and NHTSA is proposing 
fuel consumption standards on a gal/100 mile basis that would apply to 
a manufacturer's fleet of heavy-duty trucks and vans with a GVWR from 
8,500 pounds to 14,000 pounds (Class 2b and 3). CO2 is the 
primary pollutant resulting from the combustion of vehicular fuels, and 
the amount of CO2 emitted is highly correlated to the amount 
of fuel consumed. In addition, the EPA is proposing separate emissions 
standards for three other GHG pollutants: CH4, 
N2O, and HFC. CH4 and N2O emissions 
relate closely to the design and efficient use of emission control 
hardware (i.e., catalytic converters). The standards for CH4 
and N2O would be set as caps that would limit emissions 
increases and prevent backsliding from current emission levels. In lieu 
of meeting the caps, EPA is optionally proposing that manufacturer 
could offset any N2O emissions or any CH4 
emissions above the cap by taking steps to further reduce 
CO2. Separately, EPA is proposing to set standards to 
control the leakage of HFCs from air conditioning systems. EPA and 
NHTSA are requesting comment on the opportunity for manufacturers to 
earn credits toward the fleet-wide average CO2 and fuel 
consumption standards for improvements to air conditioning system 
efficiency that reduce the load on the engine and thereby reduce 
CO2 emissions and fuel consumption.
    Previously, complete vehicles with a Gross Vehicle Weight Rating of 
8,500-14,000 pounds could be certified according to 40 CFR part 86, 
subpart S. These heavy-duty chassis certified vehicles were required to 
pass emissions on both the Light-duty FTP and HFET (California 
certified only

[[Page 74260]]

requirement).\197\ These proposed rules would use the same testing 
procedures already required for heavy-duty chassis certification, 
namely the Light-duty FTP and the HFET but extend the requirement for 
chassis certification for CO2 emissions to diesel-powered 
vehicles. Currently, chassis certification is a gasoline requirement 
and a diesel option. Using the data from these two tests, EPA and NHTSA 
would compare the CO2 emissions and fuel consumption results 
against the attribute-based target. The attribute upon which the 
CO2 standard would be based would be a function of vehicle 
payload, vehicle towing capacity and two-wheel versus four-wheel drive 
configuration as discussed in Section II.C(1)(b) of this notice. The 
attribute-based standard targets would be used to determine a 
manufacturer fleet standard and would be subject to an average banking 
and trading scheme similar to the light-duty GHG rule.
---------------------------------------------------------------------------

    \197\ Diesel engines are engine-certified with the option to 
chassis certification Federally and for California.
---------------------------------------------------------------------------

    This proposal would require nearly all heavy-duty trucks between 
8,500 and 14,000 pounds gross vehicle weight rating that are not 
already covered under the light-duty truck and medium-duty passenger 
vehicle GHG standards to have a CO2, CH4 and 
N2O values assigned to them, either from actual chassis 
dynamometer testing or from the results of a representative vehicle in 
the test group with appropriate adjustments made for differences. This 
requirement would apply based on whether the vehicle manufacturer sold 
the vehicle as a complete or nearly complete vehicle.\198\ 
Manufacturers would be allowed to exclude vehicles they sell to 
secondary manufacturers without cabs (often known as rolling chassis), 
as well as a very small number of vehicles sold with cabs. 
Specifically, a manufacturer could certify up to two percent of its 
vehicles with complete cabs, or up to 2,000 vehicles if its total sales 
in this category was less than 100,000, as vocational vehicles. To the 
extent manufacturers are allowed to engine certify for criteria 
pollutant (non-GHG) requirements today, they would be allowed to 
continue to do so under the proposed regulations.
---------------------------------------------------------------------------

    \198\ The proposed regulations would use the term ``cab-complete 
vehicle'' to refer to incomplete vehicles sold with complete cabs, 
but lacking a cargo carrying container.
---------------------------------------------------------------------------

    Because the program being proposed for heavy-duty pickup trucks and 
vans is so similar to the program recently adopted for light-duty 
trucks and codified in 40 CFR part 86, subpart S, EPA is proposing to 
apply most of those subpart S regulatory provisions to heavy-duty 
pickup trucks and vans and to not recodify them in the new part 1037. 
Most of the new part 1037 would not apply for heavy-duty pickup trucks 
and vans. How 40 CFR part 86 applies, and which provisions of the new 
40 CFR part 1037 apply for heavy-duty pickup trucks and vans is 
described in Sec.  1037.104.
(a) Certification Process
    CAA section 203(a)(1) prohibits manufacturers from introducing a 
new motor vehicle into commerce unless the vehicle is covered by an 
EPA-issued certificate of conformity. Section 206(a)(1) of the CAA 
describes the requirements for EPA issuance of a certificate of 
conformity, based on a demonstration of compliance with the emission 
standards established by EPA under section 202 of the Act. The 
certification demonstration requires emission testing, and must be done 
for each model year.\199\
---------------------------------------------------------------------------

    \199\ CAA Section 206(a)(1).
---------------------------------------------------------------------------

    Under existing heavy-duty chassis certification and other EPA 
emission standard programs, vehicle manufacturers certify a group of 
vehicles called a test group. A test group typically includes multiple 
vehicle car lines and model types that share critical emissions-related 
features.\200\ The manufacturer generally selects and tests one vehicle 
to represent the entire test group for certification purposes. The test 
vehicle is the one expected to be the worst case for the criteria 
emission standard at issue.
---------------------------------------------------------------------------

    \200\ The specific test group criteria are described in 40 CFR 
86.1827-01, car lines and model types have the meaning given in 40 
CFR 86.1803-01.
---------------------------------------------------------------------------

    EPA requires the manufacturer to make a good faith demonstration in 
the certification application that vehicles in the test group will both 
(1) comply throughout their useful life within the emissions bin 
assigned, and (2) contribute to fleetwide compliance with the 
applicable emissions standards when the year is over. EPA issues a 
certificate for the vehicles included in the test group based on this 
demonstration, and includes 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 with the applicable standards.
    The certification process often occurs several months prior to 
production and manufacturer testing may occur months before the 
certificate is issued. The certification process for the existing 
heavy-duty chassis program is an efficient way for manufacturers to 
conduct the needed testing well in advance of certification, and to 
receive certificates in a time frame which allows for the orderly 
production of vehicles. The use of conditions on the certificate has 
been an effective way to ensure that manufacturers comply throughout 
their useful life and meet fleet standards when the model year is 
complete and the accounting for the individual model sales is 
performed. EPA has also adopted this approach as part of its LD GHG 
compliance program.
    EPA is proposing to similarly condition each certificate of 
conformity for the GHG program upon a manufacturer's good faith 
demonstration of compliance with the manufacturer's fleetwide average 
CO2 standard. The following discussion explains how EPA 
proposes to integrate the proposed vehicle certification program into 
the existing certification program.
    An integrated approach with NHTSA will be undertaken to allow 
manufacturers a single point of entry to address certification and 
compliance. Vehicle manufacturers would initiate the formal 
certification process with their submission of application for a 
certificate of conformity to EPA.
(b) Certification Test Groups and Test Vehicle Selection
    For heavy-duty chassis certification to the criteria emission 
standards, manufacturers currently as mentioned above divide their 
fleet into ``test groups'' for certification purposes. The test group 
is EPA's unit of certification; one certificate is issued per test 
group. These groupings cover vehicles with similar emission control 
system designs expected to have similar emissions performance (see 40 
CFR 86.1827-01). The factors considered for determining test groups 
include Gross Vehicle Weight, combustion cycle, engine type, engine 
displacement, number of cylinders and cylinder arrangement, fuel type, 
fuel metering system, catalyst construction and precious metal 
composition, among others. Vehicles having these features in common are 
generally placed in the same test group.\201\
---------------------------------------------------------------------------

    \201\ EPA provides for other groupings in certain circumstances, 
and can establish its own test groups in cases where the criteria do 
not apply. See 40 CFR 86.1827-01(b), (c) and (d).
---------------------------------------------------------------------------

    EPA is proposing to retain the current test group structure for 
heavy-duty pickups and vans in the certification requirements for 
CO2. At the time of

[[Page 74261]]

certification, manufacturers would use the CO2 emission 
level from the Emission Data Vehicle as a surrogate to represent all of 
the models in the test group. However, following certification further 
testing would generally be allowed for compliance with the fleet 
average CO2 standard as described below. EPA's issuance of a 
certificate would be conditioned upon the manufacturer's subsequent 
model level testing and attainment of the actual fleet average, much 
like light-duty CAFE and GHG compliance requires. Under the current 
program, complete heavy-duty Otto-cycle vehicles under 14,000 pounds 
Gross Vehicle Weight Rating are required to chassis certify (see 40 CFR 
86.1801-01(a)). The current program allows complete heavy-duty diesel 
vehicles under 14,000 pounds GVWR to optionally chassis certify (see 40 
CFR 86.1863-07(a)). As discussed earlier, these proposed rules would 
now require all HD vehicles under 14,000 pounds GVWR to chassis certify 
except as noted in Section II.
    EPA recognizes that the existing heavy-duty chassis test group 
criteria do not necessarily relate to CO2 emission levels. 
See 75 FR 25472. For instance, while some of the criteria, such as 
combustion cycle, engine type and displacement, and fuel metering, may 
have a relationship to CO2 emissions, others, such as those 
pertaining to the some exhaust aftertreatment features, may not. In 
fact, there are many vehicle design factors that impact CO2 
generation and emissions but are not major factors included in EPA's 
test group criteria.\202\ Most important among these may be vehicle 
weight, horsepower, aerodynamics, vehicle size, and performance 
features. To remedy this, EPA is considering allowing manufacturers 
provisions similar to the LD GHG rule that would yield more accurate 
CO2 estimates than only using the test group emission data 
vehicle CO2 emissions.
---------------------------------------------------------------------------

    \202\ EPA noted this potential lack of connection between fuel 
economy testing and testing for emissions standard purposes when it 
first adopted fuel economy test procedures. See 41 FR 38677, Sept. 
10, 1976.
---------------------------------------------------------------------------

    EPA believes that the current test group concept is appropriate for 
N2O and CH4 because the technologies that would 
be employed to control N2O and CH4 emissions may 
generally be the same as those used to control the criteria pollutants. 
However, manufacturers would determine if this approach is adequate 
method for N2O and CH4 emissions compliance or if 
testing on additional vehicles is required to ensure the entire fleet 
meet applicable standards.
    As just discussed, the ``worst case'' vehicle a manufacturer 
selects as the Emissions Data Vehicle to represent a test group under 
the existing regulations (40 CFR 86.1828-01) may not have the highest 
levels of CO2 in that group. For instance, there may be a 
heavier, more powerful configuration that would have higher 
CO2, but may, due to the way the catalytic converter has 
been matched to the engine, actually have lower NOX, CO, PM 
or HC emissions. Therefore, EPA is proposing to require a single 
Emission Data Vehicle that would represent the test group for both 
criteria pollutant and CO2 certification. The manufacturer 
would be allowed to initially apply the Emission Data Vehicle's 
CO2 emissions value to all models in the test group, even if 
other models in the test group are expected to have higher 
CO2 emissions. However, as a condition of the certificate, 
this surrogate CO2 emissions value would generally be 
replaced with actual, model-level CO2 values based on 
results from additional testing that occurs later in the model year 
much like the light-duty CAFE program, or through the use of approved 
methods for analytically derived fuel economy. This model level data 
would become the official certification test results (as per the 
conditioned certificate) and would be used to determine compliance with 
the fleet average. Only if the test vehicle is in fact the worst case 
CO2 vehicle for the test group could the manufacturer elect 
to apply the Emission Data Vehicle emission levels to all models in the 
test group for purposes of calculating fleet average emissions. 
Manufacturers would be unlikely to make this choice, because doing so 
would ignore the emissions performance of vehicle models in their fleet 
with lower CO2 emissions and would unnecessarily inflate 
their CO2 fleet average. Testing at the model level would 
necessarily increase testing burden beyond the minimum Emission Data 
Vehicle testing.
    EPA requests comment regarding whether the existing heavy-duty 
chassis test group can adequately represent CO2 emissions 
for certification purposes, and whether the Emission Data Vehicle's 
CO2 emission level is an appropriate surrogate for all 
vehicles in a test group at the time of certification, given that the 
certificate would be conditioned upon additional model level testing 
occurring during the year and that the surrogate CO2 
emission values would be replaced with model-level emissions data from 
those tests. Comments should also address EPA's desire to minimize the 
up-front pre-production testing burden and whether the proposed 
efficiencies would be balanced by the requirement to test all model 
types in the fleet by the conclusion of the model year in order to 
establish the fleet average CO2 levels.
    As explained in Sections II and III, there are two standards that 
the manufacturer would be subject to, the fleet average standard and 
the in-use standard for the useful life of the vehicle. Compliance with 
the fleet average standard is based on production weighted averaging of 
the test data that applies for each model, For each model, the in-use 
standard is set at 10 percent higher than the level used for that model 
in calculating the fleet average. The certificate covers both of these 
standards, and the manufacturer has to demonstrate compliance with both 
of these standards for purposes of receiving a certificate of 
conformity. The certification process for the in-use standard is 
discussed above.
(c) Pre-Model Year (or Compliance Plan) Reporting
    EPA and NHTSA are proposing that manufacturers submit a compliance 
plan for their entire fleet prior to the certification of any test 
group in a given model year. Preferably, this compliance plan would be 
submitted at the manufacturer's annual certification preview meeting. 
This preview meeting is typically held before the earliest date that 
the model year can begin. The earliest a model year can begin is 
January 2nd of the calendar year prior to the model year. This plan 
would include the manufacturer's estimate of its attribute-based 
standard, along with a demonstration of compliance with the standard 
based on projected model-level CO2 emissions and fuel 
consumption, and production estimates. This information would be 
similar to the information submitted to NHTSA and EPA in the pre-model 
year report required for CAFE compliance for light-duty vehicles. 
Included in the compliance plan, manufacturers seeking to take 
advantage of credit flexibilities would include these in their 
compliance demonstration. Similarly, the compliance demonstration would 
need to include a credible plan for addressing deficits accrued in 
prior model years. EPA and NHTSA would review the compliance plan for 
technical viability and conduct a certification preview discussion with 
the manufacturer. The agencies would view the compliance plan as part 
of the manufacturer's good faith demonstration, but understands that 
initial projections can vary considerably from the reality of final 
production and emission results. In

[[Page 74262]]

addition, the compliance plan must be approved by the EPA Administrator 
prior to any certificate of compliance being issued. The agencies 
request comment on the proposal to evaluate manufacturer compliance 
plans prior to the beginning of model year certification.
(d) Demonstrating Compliance With the Proposed Standards
(i) CO2 and Fuel Consumption Fleet Standards
    As noted, attribute-based CO2 standards result in each 
manufacturer having a fleet average CO2 standard unique to 
its heavy-duty truck fleet of GVWR between 8,500-14,000 pounds and that 
standard would be separate from the standard for passenger cars, light-
trucks, and other heavy-duty trucks. The standards depend on those 
attributes corresponding to the relative capability, or ``work 
factor'', of the vehicle models produced by that manufacturer. The 
proposed attributes used to determine the stringency of the 
CO2 standard are payload and towing capacity as described in 
Section II.C of this notice. Generally, fleets with a mix of vehicles 
with increased payloads or greater towing capacity (or utilizing four 
wheel drive configurations) would face numerically less stringent 
standards (i.e., higher CO2 grams/mile standards) than 
fleets consisting of less powerful vehicles. (However, the standards 
would be expected to be equally challenging and achieve similar percent 
reductions.) Although a manufacturer's fleet average standard could be 
estimated throughout the model year based on projected production 
volume of its vehicle fleet, the final compliance values would be based 
on the final model year production figures. A manufacturer's 
calculation of fleet average emissions at the end of the model year 
would be based on the production-weighted average emissions of each 
model in its fleet. The payload and towing capacity inputs used to 
determine manufacturer compliance with these proposed rules would be 
the advertised values.
    The agencies propose to use the same general vehicle category 
definitions that are used in the current EPA HD chassis certification 
(See 40 CFR 86.1816-05). The new vehicle category definitions differ 
slightly from the EPA definitions for Heavy-duty Vehicle definitions 
for the existing program, as well as other EPA vehicle programs. 
Mainly, manufacturers would be able to test, and possibly model, more 
configurations of vehicles than were historically in a given test 
group. The existing criteria pollutant program requires the worst case 
configuration be tested for emissions certification. For HD chassis 
certification, this usually meant only testing the vehicle with the 
highest ALVW, road-load, and engine displacement within a given test 
group. This worst case configuration may only represent a small 
fraction of the test group production volume. By testing the worst 
case, albeit possibly small volume, vehicle configuration, the EPA had 
a reasonable expectation that all represented vehicles would pass the 
given emissions standards. Since CO2 standards are a fleet 
standard based on a combination of sales volume and work factor (i.e., 
payload and towing capability), it may be in a manufacturer's best 
interest to test multiple configurations within a given test group to 
more accurately estimate the fleet average CO2 emission 
levels and not accept the worst case vehicle test results as 
representative of all models. Additionally, vehicle models for which a 
manufacturer desires to use analytically derived fuel economy (ADFE) to 
estimate CO2 emission levels may need additional actual test 
data for vehicle models of similar but not identical configurations. 
The agencies are requesting comment on allowing the manufacturer to 
test as many configurations within a test group as the manufacturer 
requires in order to best represent the volumes of each configuration 
within that test group. The agencies are also requesting comment on 
using an ADFE approach similar to that used by light-duty vehicles, as 
explained in the light-duty vehicle/light-duty truck EPA guidance 
document CCD-04-06 titled ``Updated Analytically Derived Fuel Economy 
(ADFE) Policy for 2005 MY and Later'', but expanded to a greater 
fraction of possible subconfigurations and using lower confidence 
limits than used for light-duty vehicles and light-duty trucks.
    The agencies are proposing the use of ADFE similar to that allowed 
for light-duty vehicles in 40 CFR 600.006-08(e). This provision would 
allow EPA and NHTSA to accept analytical expressions to generate 
CO2 and fuel economy that have been approved in advance by 
the agencies.
    For model years 2014 through 2017, or earlier if a manufacturer is 
certifying in order to generate early credits, EPA is proposing the 
equation and parameter values as expressed in Section II C or assigning 
a CO2 level to an individual vehicle's relevant attributes. 
These CO2 values would be production weighted to determine 
each manufacturer's fleet average. Each parameter would change on an 
annual basis, resulting in the annual increase in stringency. For the 
function used to describe the proposed standard, see Section II.C of 
this notice.
    The GHG and fuel economy rulemaking for light-duty vehicles adopted 
a carbon balance methodology used historically to determine fuel 
consumption for the light-duty labeling and CAFE programs, whereby the 
carbon-related combustion products HC and CO are included on an 
adjusted basis in the compliance calculations, along with 
CO2. The resulting carbon-related exhaust emissions (CREE) 
of each test vehicle is calculated and it is this value, rather than 
simply CO2 emissions, that is used in compliance 
determinations. The difference between the CREE and CO2 is 
typically very small.
    NHTSA and EPA are not proposing to adopt the CREE methodology for 
HD pickups and vans, and so are not proposing to adjust CO2 
emissions to further account for additional HC and CO. The basis of the 
CREE methodology in historical labeling and CAFE programs is not 
relevant to HD pickups and vans, because these historical programs do 
not exist for HD vehicles. Furthermore, test data used in this proposal 
for standards-setting has not been adjusted for this effect, and so it 
would create an inconsistency, albeit a small one, to apply it for 
compliance with the numerical standards we are proposing. Finally, it 
would add complexity to the program with little real world benefit. We 
request comment on this proposed approach.
(ii) CO2 In-Use Standards and Testing
    Section 202(a)(1) of the CAA requires emission standards to apply 
to vehicles throughout their statutory useful life. Section II.B(3)(b) 
of this proposal discusses in-use standards.
    Currently, EPA regulations require manufacturers to conduct in-use 
testing as a condition of certification for heavy-duty trucks between 
8,500 and 14,000 gross vehicle weight that are chassis certified. The 
vehicles are tested to determine the in-use levels of criteria 
pollutants when they are in their first and third years of service. 
This testing is referred to as the In-Use Verification Program, which 
was first implemented as part of EPA's CAP 2000 certification program 
(see 64 FR 23906, May 4, 1999).
    EPA is requesting comment on applying the in-use program already 
set forth in the 2012-2016 MY light-duty vehicle rule to heavy-duty 
pickups and vans. The In-Use Verification Program for heavy-duty 
pickups and vans would follow the same general provisions of the light-
duty program in regard to

[[Page 74263]]

testing, vehicle selection, and reporting. See 75 FR 25474-25476.
(e) Cab-Chassis Vehicles and Complete Class 4 Vehicles
    As discussed in Section I.C(2)(a), we are proposing to include most 
cab-chassis Class 2b and 3 vehicles in the complete HD pickup and van 
program. Because their numbers are relatively small, and to reduce the 
testing and compliance tracking burden to manufacturers, we would treat 
these vehicles as equivalent to the complete van or truck product they 
are derived from. The manufacturer would determine which complete 
vehicle configuration it produces most closely matches the cab-chassis 
product leaving its facility, and would include each of these cab-
chassis vehicles in the fleet averaging calculations as though it were 
identical to the corresponding complete vehicle.
    Any in-use testing of these vehicles would do likewise, with 
loading of the tested vehicle to a total weight equal to the ALVW of 
the corresponding complete vehicle configuration. If the secondary 
manufacturer had altered or replaced any vehicle components in a way 
that would substantially affect CO2 emissions from the 
tested vehicle (e.g., axle ratio has been changed for a special purpose 
vehicle), the vehicle manufacturer could request that EPA not test the 
vehicle or invalidate a test result. Secondary (finisher) manufacturers 
would not be subject to requirements under this provision, other than 
to comply with anti-tampering regulations. However, if they modify 
vehicle components in such a way that GHG emissions and fuel 
consumption are substantially affected, they become manufacturers 
subject to the standards under this proposal.
    We realize that this approach does not capture the likely loss of 
aerodynamic efficiency involved in converting these vehicles from 
standard pickup trucks or vans to ambulances and the like, and thus it 
could assign them lower GHG emissions and fuel consumption than they 
deserve. However, we feel that this approach strikes a fair balance 
between the alternatives--grouping these vehicles with vocational 
vehicles subject only to engine standards and tire requirements, or 
creating a complex and burdensome program that forces vehicle 
manufacturers to track, and perhaps control, a plethora of vehicle 
configurations they currently do not manage. We request comment on this 
proposed provision and any suggestions for ways to improve it.
    Some complete Class 4 trucks are very similar to complete Class 3 
pickup truck models, including their overall vehicle architecture and 
use of the same basic engines. EPA and NHTSA request comment on whether 
these vehicles should be regulated as part of the HD pickup and van 
category and thereby be subject to that regulatory regime (i.e., 
standard stringency, chassis-based compliance for entire vehicle, 
credit opportunities limited to HD pickup and van subcategory, etc.), 
instead of as vocational vehicles as currently proposed. Comment is 
also requested on whether such chassis certification should be allowed 
as a manufacturer's option instead, and on whether vehicles so 
certified for GHG emissions and fuel consumption should also be allowed 
to certify to chassis-based criteria pollutant standards as well. 
Commenters are asked to address the environmental impacts of this 
potential change.
(2) Proposed Labeling Provisions
    HD pickups and vans currently have vehicle emission control 
information labels showing compliance with criteria pollutant 
standards, similar to emission control information labels for engines. 
As with engines, we believe this label is sufficient.
(3) Other Certification Issues
(a) Carryover Certification Test Data
    EPA's proposed certification program for vehicles allows 
manufacturers to carry certification test data over from one model year 
to the next, when no significant changes to models are made. EPA will 
also apply this policy to CO2, N2O and 
CH4 certification test data.
(b) Compliance Fees
    The CAA allows EPA to collect fees to cover the costs of issuing 
certificates of conformity for the classes of vehicles and engines 
covered by this proposal. On May 11, 2004, EPA updated its fees 
regulation based on a study of the costs associated with its motor 
vehicle and engine compliance program (69 FR 51402). At the time that 
cost study was conducted the current rulemaking was not considered.
    At this time the extent of any added costs to EPA as a result of 
this proposal is not known. EPA will assess its compliance testing and 
other activities associated with the rule and may amend its fees 
regulations in the future to include any warranted new costs.

C. Heavy-Duty Engines

(1) Proposed Compliance Approach
    Section 203 of the CAA requires that all motor vehicles and engines 
sold in the United States to carry a certificate of conformity issued 
by the U.S. EPA. For heavy-duty engines, the certificate specifies that 
the engine meets all requirements as set forth in the regulations (40 
CFR part 86, subpart N, for criteria pollutants) including the 
requirement that the engine be compliant with emission standards. This 
demonstration is completed through emission testing as well as 
durability testing to determine the level of emissions deterioration 
throughout the useful life of the engine. In addition to compliance 
with emission standards, manufacturers are also required to warrant 
their products against emission defects, and demonstrate that a service 
network is in place to correct any such conditions. The engine 
manufacturer also bears responsibility in the event that an emission-
related recall is necessary. Finally, the engine manufacturer is 
responsible for tracking and ensuring correct installation of any 
emission related components installed by a second party (i.e., vehicle 
manufacturer). EPA believes this compliance structure is also valid for 
administering the proposed GHG regulations for heavy-duty engines.
(a) Certification Process
    In order to obtain a certificate of conformity, engine 
manufacturers must complete a compliance demonstration, normally 
consisting of test data from relatively new (low-hour) engines as well 
as supporting documentation, showing that their product meets emission 
standards and other regulatory requirements. To account for aging 
effects, low-hour test results are coupled with testing-based 
deterioration factors (DFs), which provide a ratio (or offset) of end-
of-life emissions to low-hour emissions for each pollutant being 
measured. These factors are then applied to all subsequent low-hour 
test data points to predict the emissions behavior at the end of the 
useful life.
    For purposes of this compliance demonstration and certification, 
engines with similar engine hardware and emission characteristics 
throughout their useful life may be grouped together in engine 
families, consistent with current criteria-pollutant certification 
procedures. Examples of such characteristics are the combustion cycle, 
aspiration method, and aftertreatment system. Under this system, the 
worst-case engine (``parent rating'') is selected based on having the 
highest fuel feed per engine stroke, and all emissions testing is 
completed on this model. All other models within the family (``child 
ratings'') are expected to have emissions at or below the parent model 
and therefore in compliance with emission standards. Any engine within 
the family

[[Page 74264]]

can be subject to selective enforcement audits, in-use, confirmatory, 
or other compliance testing.
    We are proposing to continue to use this approach for the selection 
of the worst-case engine (``parent rating'') for fuel consumption and 
GHG emissions as well. We believe this is appropriate because this 
worst case engine configuration would be expected to have the highest 
in-use fuel consumption and GHG emissions within the family. We note 
that lower engine ratings contained within this family would be 
expected to have a higher fuel consumption rate when measured over the 
Federal Test Procedures as expressed in terms of fuel consumption per 
brake horsepower hour. This higher fuel consumption rate is misleading 
in the context of comparing engines within a single engine family. This 
seeming contradiction can be most easily understood in terms of an 
example. For a typical engine family a top rating could be 500 
horsepower with a number of lower engine ratings down to 400 horsepower 
or lower included within the family. When installed in identical trucks 
the 400 and 500 horsepower engines would be expected to operate 
identically when the demanded power from the engines is 400 horsepower 
or less. So in the case where in-use driving never included 
acceleration rates leading to horsepower demand greater than 400 
horsepower, the two trucks with the 400 and 500 horsepower engines 
would give identical fuel consumption and GHG performance. When the 
desired vehicle acceleration rates were high enough to require more 
than 400 horsepower, the 500 horsepower truck would accelerate faster 
than the 400 horsepower truck resulting in higher average speeds and 
higher fuel consumption and GHG emissions measured on a per mile or per 
ton-mile basis. Hence, the higher rated engine family would be expected 
to have the highest in-use fuel consumption and CO2 
emissions.
    The reason that the lower engine ratings appear to have worse fuel 
consumption relates to our use of a brake specific work metric. The 
brake specific metric measures power produced from the engine and 
delivered to the vehicle ignoring the parasitic work internal to the 
engine to overcome friction and air pumping work within the engine. The 
fuel consumed and GHG emissions produced to overcome this internal work 
and to produce useful (brake) work are both measured in the test cycle 
but only the brake work is reflected in the calculation of the fuel 
consumption rate. This is desirable in the context of reducing fuel 
consumption as this approach rewards engine designs that minimize this 
internal work through better engine designs. The less work that is 
needed internal to the engine, the lower the fuel consumption will be. 
If we included the parasitic work in the calculation of the rate, we 
would provide no incentive to reduce internal friction and pumping 
losses. However, when comparing two engines within the very same family 
with identical internal work characteristics, this approach gives a 
misleading comparison between two engines as described above. This is 
the case because both engines have an identical fuel consumption rate 
to overcome internal work but different rates of brake work with the 
higher horsepower rating having more brake work because the test cycle 
is normalized to 100 percent of the engine's rated power. The fuel 
consumed for internal work can be thought of as a fixed offset 
identical between both engines. When this fixed offset is added to the 
fuel consumed for useful (brake) work over the cycle, it increases the 
overall fuel consumption (the numerator in the rate) without adding any 
work to the denominator. This fixed offset identical between the two 
engines has a bigger impact on the lower engine rating. In the extreme 
this can be seen easily. As the engine ratings decrease and approach 
zero, the brake work approaches zero and the calculated brake specific 
fuel consumption approaches infinity. For these reasons, we are 
proposing that the same selection criteria, as outlined in 40 CFR part 
86, subpart N, be used to define a single engine family designation for 
both criteria pollutant and GHG emissions. Further, we are proposing 
that for fuel consumption and CO2 emissions only any 
selective enforcement audits, in-use, confirmatory, or other compliance 
testing would be limited to the parent rating for the family. This 
approach is being contemplated for administrative convenience and we 
seek comments on alternatives to address compliance testing. Consistent 
with the current regulations, manufacturers may electively subdivide a 
grouping of engines which would otherwise meet the criteria for a 
single family if they have evidence that the emissions are different 
over the useful life.
    The agency utilizes a 12-digit naming convention for all mobile-
source engine families (and test groups for vehicles). This convention 
is also shared by the California Air Resources Board which allows 
manufacturers to potentially use a single family name for both EPA and 
California ARB certification. Of the 12 digits, 9 are EPA-defined and 
provide identifying characteristics of the engine family. The first 
digit represents the model year, through use of a predefined code. For 
example, ``A'' corresponds to the 2010 model year and ``B'' corresponds 
to the 2011 model year. The 5th position corresponds to the industry 
sector code, which includes such examples as light-duty vehicle (V) and 
heavy-duty diesel engines (H). The next three digits are a unique 
alphanumeric code assigned to each manufacturer by EPA. The next four 
digits describe the displacement of the engine; the units of which are 
dependent on the industry segment and a decimal may be used when the 
displacement is in liters. For engine families with multiple 
displacements, the largest displacement is used for the family name. 
For on-highway vehicles and engines, the tenth character is reserved 
for use by California ARB. The final characters (including the 10th 
character in absence of California ARB guidance) left to the 
manufacturer to determine, such that the family name forms a unique 
identifying characteristic of the engine family.
    This convention is well understood by the regulated industries, 
provides sufficient detail, and is flexible enough to be used across a 
wide spectrum of vehicle and engine categories. In addition, the 
current harmonization with other regulatory bodies reduces 
complications for affected manufacturers. For these reasons, we are not 
proposing any major changes to this naming convention for this 
proposal. There may be additional categories defined for the 5th 
character to address heavy-duty vehicle test groups, however that will 
be discussed later.
    As with criteria pollutant standards, the heavy-duty diesel 
regulatory category is subdivided into three regulatory subcategories, 
depending on the GVW of the vehicle in which the engine will be used. 
These regulatory subcategories are defined as light-heavy-duty (LHD) 
diesel, medium heavy-duty (MHD) diesel, and heavy heavy-duty (HHD) 
diesel engines. All heavy-duty gasoline engines are grouped into a 
single subcategory. Each of these regulatory subcategories are expected 
to be in service for varying amounts of time, so they each carry 
different regulatory useful lives. For this reason, expectations for 
demonstrating useful life compliance differ by subcategory, 
particularly as related to deterioration factors.
    Light heavy-duty diesel engines (and all gasoline heavy-duty 
engines) have

[[Page 74265]]

the same regulatory useful life as a light-duty vehicle (110,000 
miles), which is significantly shorter than the other heavy-duty 
regulatory subcategories. Therefore, we believe it is appropriate to 
maintain commonality with the light-duty GHG rule. During the light-
duty GHG rulemaking, the conclusion was reached that no significant 
deterioration would occur over the useful life. Therefore, EPA is 
proposing to specify that manufacturers would use assigned DFs for 
CO2 and the values would be zero (for additive DFs) and one 
(for multiplicative DFs). EPA is interested in data that addresses this 
issue.
    For the medium heavy-duty and heavy heavy-duty diesel engine 
segments, the regulatory useful lives are significantly longer (185,000 
and 435,000 miles, respectively). For this reason, the agency is not 
convinced that engine/aftertreatment wear will not have a negative 
impact on GHG emissions. To address useful life compliance for MHD and 
HHD diesel engines certified to GHG standards, we believe the criteria 
pollutant approach for developing DFs is appropriate. Using 
CO2 as an example, many of the engine deterioration concerns 
previously identified will affect CO2 emissions. Reduced 
compression, as a result of wear, will cause higher fuel consumption 
and increase CO2 production. In addition, as aftertreatment 
devices age (primarily particulate traps), regeneration events may 
become more frequent and take longer to complete. Since regeneration 
commonly requires an increase in fuel rate, CO2 emissions 
would likely increase as well. Finally, any changes in EGR levels will 
affect heat release rates, peak combustion temperatures, and 
completeness of combustion. Since these factors could reasonably be 
expected to change fuel consumption, CO2 emissions would be 
expected to change accordingly.
    HHD diesel engines may also require some degree of aftertreatment 
maintenance throughout their useful life. For example, one major heavy-
duty engine manufacturer specifies that their diesel particulate 
filters be removed and cleaned at intervals between 200,000 and 400,000 
miles, depending on the severity of service. Another major engine 
manufacturer requires servicing diesel particulate filters at 300,000 
miles. This maintenance or lack thereof if service is neglected, could 
have serious negative implications to CO2 emissions. In 
addition, there may be emissions-related warranty implications for 
manufacturers to ensure that if rebuilding or specific emissions 
related maintenance is necessary, it will occur at the prescribed 
intervals. Therefore, it is imperative that manufacturers are detailed 
in their maintenance instructions. The agency currently seeks public 
comment on how to properly address this issue.
    Lean-NOX aftertreatment devices may also facilitate GHG 
reductions by allowing engines to run with higher engine-out 
NOX levels in exchange for more efficient calibrations. In 
most cases, these aftertreatment devices require a consumable 
reductant, such as diesel exhaust fluid, which requires periodic 
maintenance by the vehicle operator. Without such maintenance, the 
emission control system may be compromised and compliance with emission 
standards may be jeopardized. Such maintenance is considered to be 
critical emission related maintenance and manufacturers must therefore 
demonstrate that it is likely to be completed at the required 
intervals. One example of such a demonstration is an engine power de-
rate strategy that will limit engine power or vehicle speed in absence 
of this required maintenance.
    If the manufacturer determines that maintenance is necessary on 
critical emission-related components within the useful life period, 
they must have a reasonable basis for ensuring that this maintenance 
will be completed as scheduled. This includes any adjustment, cleaning, 
repair, or replacement of critical emission-related components. 
Typically, the agency has only allowed manufacturers to schedule such 
maintenance if the manufacturer can demonstrate that the maintenance is 
reasonably likely to be done at the recommended intervals. This 
demonstration may be in the form of survey data showing at least 80 
percent of in-use engines get the prescribed maintenance at the correct 
intervals. Another possibility is to provide the maintenance free of 
charge. We see no reason to depart from this approach for GHG-related 
critical emission-related components; however the agency welcomes 
commentary on this approach.
(b) Demonstrating Compliance With the Proposed Standards
(i) CO2 Standards
    The final test results (adjusted for deterioration, if applicable) 
form the basis for the Family Certification Limit (FCL), which the 
manufacturer must specify to be at or above the certification test 
results. This FCL becomes the emission standard for the family and any 
certification or confirmatory testing must show compliance with this 
limit. In addition, manufacturers may choose an FCL at any level above 
their certified emission level to provide a larger compliance margin. 
If subsequent certification or confirmatory testing reveals emissions 
above the FCL, the new, higher result becomes the FCL.
    The FCL is also used to determine the Family Emission Limit (FEL), 
which serves as the emission limit for any subsequent field testing 
conducted after the time of certification. This would primarily include 
selective enforcement audits, but also may include in-use testing and/
or production line testing for GHGs. The FEL differs from the FCL in 
that it includes an EPA-defined compliance margin; currently proposed 
to be 2 percent. Under this scenario the FEL would always be 2 percent 
higher than the FCL.
 Engine Emission Testing
    Under current non-GHG engine emissions regulations, manufacturers 
are required to demonstrate compliance using two test methods: The 
heavy-duty transient cycle and the heavy-duty steady state test. Each 
test is an engine speed versus engine torque schedule intended to be 
run on an engine dynamometer. Over each test, emissions are sampled 
using the equipment and procedures outlined in 40 CFR part 1065, which 
includes provisions for measuring CO2, N2O, and 
CH4. Emissions may be sampled continuously or in a batch 
configuration (commonly known as ``bag sampling'') and the total mass 
of emissions over each cycle are normalized by the engine power 
required to complete the cycle. Following each test, a validation check 
is made comparing actual engine speed and torque over the cycle to the 
commanded values. If these values do not align well, the test is deemed 
invalid.
    The transient Heavy-duty FTP cycle is characteristic of typical 
urban stop-and-go driving. Also included is a period of more steady 
state operation that would be typical of short cruise intervals at 45 
to 55 miles per hour. Each transient test consists of two 20 minute 
tests separated by a ``soak'' period of 20 minutes. The first test is 
run with the engine in a ``cold'' state, which involves letting the 
engine cool to ambient conditions either by sitting overnight or by 
forced cooling provisions outlined in Sec.  86.1335-90 (or 40 CFR part 
1036). This portion of the test is meant to assess the ability of the 
engine to control emissions during the period prior to reaching normal 
operating temperature. This is commonly a challenging area in criteria 
pollutant emission control, as cold combustion chamber surfaces tend to 
inhibit mixing and vaporization of

[[Page 74266]]

fuel and aftertreatment devices do not tend to function well at low 
temperatures.
    Following the first test, the engine is shut off for a period of 20 
minutes, during which emission analyzer checks are performed and 
preparations are made for the second test (also known as the ``hot'' 
test). After completion of the second test, the results from the cold 
and hot tests are weighted and a single composite result is calculated 
for each pollutant. Based on typical in-use duty cycles, the cold test 
results are given a \1/7\ weighting and the hot test results are given 
a \6/7\ weighting. Deterioration factors are applied to the final 
weighted results and the results are then compared to the emission 
standards.
    Prior to 2007, compliance only needed to be demonstrated over the 
Heavy-duty FTP. However, a number of events brought to light the fact 
that this transient cycle may not be as well suited for engines which 
spend much of their duty cycle at steady cruise conditions, such as 
those used in line-haul semi-trucks. As a result, the steady-state SET 
procedure was added, consisting of 13 steady-state modes. During each 
mode, emissions were sampled for a period of five minutes. Weighting 
factors were then applied to each mode and the final weighted results 
were compared to the emission standards (including deterioration 
factors). In addition, emissions at each mode could not exceed the NTE 
emission limits. Alternatively, manufacturers could run the test as a 
ramped-modal cycle. In this case, the cycle still consists of the same 
speed/torque modes, however linear progressions between points are 
added and instead of weighting factors, each mode is sampled for 
various amounts of time. The result is a continuous cycle lasting 
approximately 40 minutes. With the implementation of part 1065 test 
procedures in 2010, manufacturers are now required to run the modal 
test as a ramped-modal cycle. In addition, the order of the speed/
torque modes in the ramped-modal cycle have changed for 2010 and later 
engines.
    It is well known that fuel consumption, and therefore 
CO2 emissions, are highly dependent on the drive cycle over 
which they are measured. Steady cruise conditions, such as highway 
driving, tend to be more efficient, having lower fuel consumption and 
CO2 emissions. In contrast, highly transient operation, such 
as city driving, tends to lead to lower efficiency and therefore higher 
fuel consumption and CO2 emissions. One example of this is 
the difference between EPA-measured city and highway fuel economy 
ratings assigned to all new light-duty passenger vehicles.
    For this heavy-duty engine and vehicle proposal, we believe it is 
important to assess CO2 emissions and fuel consumption over 
both transient and steady state test cycles, as all vehicles will 
operate in conditions typical of each cycle at some point in their 
useful life. However, due to the drive cycle dependence of 
CO2 emissions, we do not believe it is reasonable to have a 
single CO2 standard which must be met for both cycles. A 
single CO2 standard would likely prove to be too lax for 
steady-state conditions while being too strict for transient 
conditions. Therefore, the agencies are recommending that all heavy-
duty engines be tested over both transient and steady-state tests. 
However, only the results from either the transient or steady-state 
test cycles would be used to assess compliance with GHG standards, 
depending on the type of vehicle in which the engine will be used. 
Engines that will be used in Class 7 and 8 tractors would use the 
ramped-modal cycle for GHG certification, and engines used in 
vocational vehicles would use the Heavy-duty FTP cycle. In both cases, 
results from the other test cycle would be reported but not used for a 
compliance decision. Engines will continue to be required to show 
criteria pollutant compliance over both cycles, in addition to NTE 
requirements.
    The agencies propose that manufacturers submit both composite data 
sets, as well as modal data for criteria and GHG pollutants for engine 
certification. This would include submission of discrete mode results 
from the continuous analyzer data collected during the ramped-modal 
cycle test. This would also include providing both cold start and hot 
start transient heavy-duty FTP emissions results, as well as the 
composite emissions at the time of certification. In an effort to 
improve the accuracy of the simulation model being used for assessing 
CO2 and fuel consumption performance and overall engine 
emissions performance, gaseous pollutants sampled using continuous 
analyzers (including but not limited to emissions results for 
CO2, CO, and NOX) would need to provide the 
constituent data from each of the test modes. The agencies welcome 
comment on this proposed requirement. As explained above in Section II, 
the agencies are proposing an alternative standard whereby 
manufacturers may elect that certain of their engine families meet an 
alternative percent reduction standard, measured from the engine 
family's 2011 baseline, instead of the main 2014 MY standard. As part 
of the certification process, manufacturers electing this standard 
would not only have to notify the agency of the election but also 
demonstrate the derivation of the 2011 baseline CO2 emission 
level for the engine family. Manufacturers would also have to 
demonstrate that they have exhausted all credit opportunities.
Durability Testing
    Another element of the current certification process is the 
requirement to complete durability testing to establish DFs. As 
previously mentioned, manufacturers are required to demonstrate that 
their engines comply with emission standards throughout the regulatory 
compliance period of the engine. This demonstration is commonly made 
through the combination of low-hour test results and testing based 
deterioration factors.
    For engines without aftertreatment devices, deterioration factors 
primarily account for engine wear as service is accumulated. This 
commonly includes wear of valves, valve seats, and piston rings, all of 
which reduce in-cylinder pressure. Oil control seals and gaskets also 
deteriorate with age, leading to higher lubricating oil consumption. 
Additionally, flow properties of EGR systems may change as deposits 
accumulate and therefore alter the mass of EGR inducted into the 
combustion chamber. These factors, amongst others, may serve to reduce 
power, increase fuel consumption, and change combustion properties; all 
of which affect pollutant emissions.
    For engines equipped with aftertreatment devices, DFs take into 
account engine deterioration, as described above, in addition to aging 
affects on the aftertreatment devices. Oxidation catalysts and other 
catalytic devices rely on active precious metals to effectively convert 
and reduce harmful pollutants. These metals may become less active with 
age and therefore pollutant conversion efficiencies may decrease. 
Particulate filters may also experience reduced trapping efficiency 
with age due to ash accumulation and/or degradation of the filter 
substrate, which may lead to higher tailpipe PM measurements and/or 
increased regeneration frequency. If a pollutant is predominantly 
controlled by aftertreatment, deterioration of emission control depends 
on the continued operation of the aftertreatment device much more so 
than on consistent engine-out emissions.
    At this time, we anticipate that most engine component wear will 
not have a significant negative impact on CO2 emissions. 
However, wear and aging of

[[Page 74267]]

aftertreatment devices may or may not have a significant negative 
impact on CO2 emissions. In addition, future engine or 
aftertreatment technologies may experience significant deterioration in 
CO2 emissions performance over the useful life of the 
engine. For these reasons, we believe that the use of DFs for 
CO2 emissions is both appropriate and necessary. As with 
criteria pollutant emissions, these DFs are preferably developed 
through testing the engine over a representative duty cycle for an 
extended period of time. This is typically either half or full useful 
life, depending on the regulatory class. The DFs are then calculated by 
comparing the high-hour to low-hour emission levels, either by division 
or subtraction (for multiplicative & additive DFs, respectively).
    This testing process may be a significant cost to an engine 
manufacturer, mainly due to the amount of time and resources required 
to run the engine out to half or full useful life. For this reason, 
durability testing for the determination of DFs is not commonly 
repeated from model year to model year. In addition, some DFs may be 
allowed to carry over between families sharing a common architecture 
and aftertreatment system. EPA prefers to have manufacturers develop 
testing-based DFs for their products, and we are proposing that this be 
the case for the final rule. However, we do understand that for the 
reasons stated above, it may be impractical to expect manufacturers to 
have testing-based deterioration factors available for this proposal. 
Therefore, we are willing to consider requiring the use of assigned DFs 
for CO2. Under this possibility, we suggest that 
manufacturers would be required to submit any CO2 data from 
durability testing to aid in developing more accurate assigned DFs.
IRAFs/Regeneration Impacts on CO2
    Heavy-duty engines may be equipped with exhaust aftertreatment 
devices which require periodic ``regeneration'' to return the device to 
a nominal state. A common example is a diesel particulate filter, which 
accumulates PM as the engine is operated. When the PM accumulation 
reaches a threshold such that exhaust backpressure is significantly 
increased, exhaust temperature is actively increased to oxidize the 
stored PM. The increase in exhaust temperature is commonly facilitated 
through late combustion phasing and/or raw fuel injection into the 
exhaust system upstream of the filter. Both methods impact emissions 
and therefore must be accounted for at the time of certification. In 
accordance with Sec.  86.004-28(i), this type of event would be 
considered infrequent because in most cases they only occur once every 
30 to 50 hours of engine operation (rather than once per transient test 
cycle), and therefore adjustment factors must be applied at 
certification to account for these effects.
    Similar to DFs, these adjustment factors are based off of 
manufacturer testing; however this testing is far less time consuming. 
Emission results are measured from two test cycles: With and without 
regeneration occurring. The differences in emission results are used, 
along with the frequency at which regeneration is expected to occur, to 
develop upward and downward adjustment factors. Upward adjustment 
factors are added to all emission results derived from a test cycle in 
which regeneration did not occur. Similarly, downward adjustment 
factors are subtracted from results based on a cycle which did 
experience a regeneration event. Each pollutant will have a unique set 
of adjustment factors and additionally, separate factors are commonly 
developed for transient and steady-state test cycles.
    The impact of regeneration events on criteria pollutants varies by 
pollutant and the aftertreatment device(s) used. In general, the 
adjustment factor can have a very significant impact on compliance with 
the NOX standard. For this reason, heavy-duty vehicle and 
engine manufacturers are already very well motivated to extend the 
regeneration frequency to as long an interval as possible and to reduce 
the regeneration as much as possible. Both of these actions 
significantly reduce the impact of regeneration on CO2 
emissions and fuel consumption. We do not believe that adding an 
adjustment factor for infrequent regeneration to the CO2 or 
fuel efficiency standards would provide a significant additional 
motivation for manufacturers to reduce regenerations. Moreover, doing 
so would add significant and unnecessary uncertainty to our projections 
of CO2 and fuel consumption performance in 2014 and beyond. 
In addressing that uncertainty, the agencies would have to set less 
stringent fuel efficiency and CO2 standards for heavy-duty 
trucks and engines. Therefore, we are not proposing to include an 
infrequent regeneration adjustment factor for CO2 or fuel 
efficiency in this program. The agencies are seeking public commentary 
on this approach.
Auxiliary Emission Control Devices
    As part of the engine control strategy, there may be devices or 
algorithms which reduce the effectiveness of emission control systems 
under certain limited circumstances. These strategies are referred to 
as Auxiliary Emission Control Devices (AECDs). One example would be the 
reduced use of EGR during cold engine operation. In this case, low 
coolant temperatures may cause the electronic control unit to reduce 
EGR flow to improve combustion stability. Once the engine warms up, 
normal EGR rates are resumed and full NOX control is 
achieved.
    At the time of certification, manufacturers are required to 
disclose all AECDs and provide a full explanation of when the AECD is 
active, which sensor inputs effect AECD activation, and what aspect of 
the emission control system is affected by the AECD. Manufacturers are 
further required to attest that their AECDs are not ``defeat-devices,'' 
which are intentionally targeted at reducing emission control 
effectiveness.
    Several common AECDs disclosed for criteria pollutant certification 
will have a similarly negative influence on GHG emissions as well. One 
such example is cold-start enrichment, with provides additional fueling 
to stabilize combustion shortly after initially starting the engine. 
From a criteria pollutant perspective, HC emissions can reasonably be 
expected to increase as a result. From a GHG perspective, the extra 
fuel does not result in a similar increase in power output and 
therefore the efficiency of the engine is reduced, which has a negative 
impact on CO2 emissions. In addition, there may be AECDs 
that uniquely reduce GHG emission control effectiveness. Therefore, 
consistent with today's certification procedures, we are proposing that 
a comprehensive list of AECDs covering both criteria pollutant, as well 
as GHG emissions is required at the time of certification.
(ii) EPA's N2O and CH4 Standards
    In 2009, EPA issued rules requiring manufacturers of mobile-source 
engines to report the emissions of CO2, N2O, and 
CH4 (74 FR 56260, October 30, 2009). While CO2 is 
commonly measured during certification testing, CH4 and 
N2O are not. CH4 has traditionally not been 
included in criteria pollutant regulations because it is a relatively 
stable molecule and does not contribute significantly to ground-level 
ozone formation. In addition, N2O is commonly a byproduct of 
lean-NOX aftertreatment systems. Until recently, these types 
of systems were not widely used on heavy-duty engines and therefore 
N2O emissions were insignificant. Both species, while 
emitted in small quantities relative to

[[Page 74268]]

CO2, have much higher global warming potential than 
CO2 and therefore must be considered as part of a 
comprehensive GHG regulation.
    EPA is proposing that CH4 and N2O be reported 
at the time of certification. We are proposing to allow manufacturers 
to use a compliance statement based on good engineering judgment for 
the first year of the program in lieu of direct measurement of 
N2O. However, beginning in the 2015 model year, the agency 
is proposing to require the direct measurement of N2O for 
certification. The intent of the CH4 and N2O 
standards are more focused on prevention of future increases in these 
compounds, rather than forcing technologies that reduce these 
pollutants. As one example, we envision manufacturers satisfying this 
requirement by continuing to use catalyst designs and formulations that 
appropriately control N2O emissions rather than pursuing a 
catalyst that may increase N2O. In many ways this becomes a 
design-based criterion in that the decision of one catalyst over 
another will effectively determine compliance with N2O 
standards over the useful life of the engine. As noted in Section II 
above, 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 proposing assigned factors corresponding to 
no deterioration. We are therefore asking for comment on this subject.
(c) Additional Compliance Provisions
(i) Warranty & Defect Reporting
    Under section 207 of the CAA, engine manufacturers are required to 
warrant that their product is free from defects that would cause the 
engine to not comply with emission standards. This warranty must be 
applicable from when the engine is introduced into commerce through a 
period generally defined as half of the regulatory useful life 
(specified in hours and years, whichever comes first). The exact time 
of this warranty is dependent on the regulatory class of the engine. In 
addition, components that are considered ``high cost'' are required to 
have an extended warranty. Examples of such components would be exhaust 
aftertreatment devices and electronic control units.
    Current warranty provisions in 40 CFR part 86 define the warranty 
periods and covered components for heavy-duty engines. The current list 
of components is comprised of any device or system whose failure would 
result in an increase in criteria pollutant emissions. At this point, 
we believe this list to be adequate for addressing GHG emissions as 
well. However, there may be instances where the failure of a component 
or system may reduce the efficiency of the engine while not increasing 
criteria pollutant emissions. In this case, the component or system may 
be inappropriately left off the list of covered components. Therefore 
we are seeking public comment on what devices and/or systems may need 
to be added to the warranted component list to adequately address GHG 
emissions. The following list identifies items commonly defined as 
critical emission-related components:
     Electronic control units.
     Aftertreatment devices.
     Fuel metering components.
     EGR-System components.
     Crankcase-ventilation valves.
     All components related to charge-air compression and 
cooling.
     All sensors and actuators associated with any of these 
components.
    When a manufacturer experiences an elevated rate of failure of an 
emission control device, they are required to submit defect reports to 
the EPA. These reports will generally have an explanation of what is 
failing, the rate of failure, and any possible corrections taken by the 
manufacturer. Based on how successful EPA believes the manufacturer to 
be in addressing these failures, the manufacturer may need to conduct a 
product recall. In such an instance, the manufacturer is responsible 
for contacting all customers with affected units and repairing the 
defect at no cost to them. We believe this structure for the reporting 
of criteria pollutant defects, and recalls, is appropriate for 
components related to complying with GHG emissions as well.
(ii) Maintenance
    Engine manufacturers are required to outline maintenance schedules 
that ensure their product will remain in compliance with emission 
standards throughout the useful life of the engine. This schedule is 
required to be submitted as part of the application for certification. 
Maintenance that is deemed to be critical to ensuring compliance with 
emission standards is classified as ``critical emission-related 
maintenance.'' Generally, manufacturers are discouraged from specifying 
that critical emission-related maintenance is needed within the 
regulatory useful life of the engine. However, if such maintenance is 
unavoidable, manufacturers must have a reasonable basis for ensuring it 
is performed at the correct time. This may be demonstrated through 
several methods including survey data indicating that at least 80% of 
engines receive the required maintenance in-use or manufacturers may 
provide the maintenance at no charge to the user. During durability 
testing of the engine, manufacturers are required to follow their 
specified maintenance schedule.
    Maintenance relating to components relating to reduction of GHG 
emissions are not expected to present unique challenges. Therefore, we 
are not proposing any changes to the provisions for the specification 
of emission-related maintenance as outlined in 40 CFR part 86.
(2) Proposed Enforcement Provisions
(a) Emission Control Information Labels
    Current provisions for engine certification require manufacturers 
to equip their product with permanent emission control information 
labels. These labels list important characteristics, parameters, and 
specifications related to the emissions performance of the engine. 
These include, but are not limited to, the manufacturer, model, 
displacement, emission control systems, and tune-up specifications. In 
addition, this label also provides a means for identifying the engine 
family name, which can then be referenced back to certification 
documents. This label provides essential information for field 
inspectors to determine that an engine is in fact in the certified 
configuration.
    We do not anticipate any major changes needing to be made to 
emission control information labels as a result of new GHG standards 
and a single label is appropriate for both criteria pollutant and GHG 
emissions purposes. Perhaps the most significant addition would be the 
inclusion of Family Certification Levels or Family Emission Limits for 
GHG pollutants, if the manufacturer is participating in averaging, 
banking, and trading. In addition, the label will need to indicate 
whether the engine is certified for use in vocational vehicles, 
tractors, or both.
(b) In-Use Standards
    In-use testing of engines provides a number of benefits for 
ensuring useful life compliance. In addition to verifying compliance 
with emission standards at any given point in the useful life, it can 
be used along with manufacturer defect reporting, to indentify 
components failing at a higher than normal rate. In this case, a 
product recall or other service campaign can be initiated and the 
problem can be rectified. Another key benefit of in-use testing is the 
discouragement of control strategies

[[Page 74269]]

catered to the certification test cycles. In the past, engine 
manufacturers were found to be producing engines that performed 
acceptably over the certification test cycle, while changing to 
alternate operating strategies ``off-cycle'' which caused increases in 
criteria pollutant emissions. While these strategies are clearly 
considered defeat devices, in-use testing provides a meaningful way of 
ensuring that such strategies are not active under normal engine 
operation.
    Currently, manufacturers of certified heavy-duty engines are 
required to conduct in-use testing programs. The intent of these 
programs is to ensure that their products are continuing to meet 
criteria pollutant emission standards at various points within the 
useful life of the engine. Since initial certification is based on 
engine dynamometer testing, and removing in-use engines from their 
respective vehicles is often impractical, a unique testing procedure 
was developed. This includes using portable emission measurement 
systems (PEMS) and testing the engine over typical in-situ drive routes 
rather than a prescribed test cycle. To assess compliance, emission 
results from a well defined area of the speed/torque map of the engine, 
known as the NTE zone, are compared to the emission standards. To 
account for potential increases in measurement and operational 
variability, certain allowances are applied to the standard which 
results in the standard for NTE measurements (NTE limit) to be at or 
above the duty cycle emission standards.
    In addition, EPA also conducts an annual in-use testing program of 
heavy-duty engines. Testing procured vehicles with specific engines 
over well-defined drive routes using a constant trailer load allows for 
a consistent comparison of in-use emissions performance. If potential 
problems are identified in-situ, the engine may be removed from the 
vehicle and tested using an engine dynamometer over the certification 
test cycles. If deficiencies are confirmed the agency will either work 
with the manufacturer to take corrective action or proceed with 
enforcement action against the manufacturer.
    The GHG reporting rule requires manufacturers to submit 
CO2 data from all engine testing (beginning in the 2011 
model year), which we believe is equally applicable to in-use 
measurements. Methods of CO2 in-situ measurement are well 
established and most, if not all, PEMS devices measure and record 
CO2 along with criteria pollutants. CH4 and 
N2O present in-situ measurement challenges that may be 
impractical to overcome for this testing, and therefore it is not 
recommended that they be included in in-use testing requirements at 
this time. While measurement of CO2 may be practical and 
important, implementing an NTE emission standard for CO2 is 
challenging. As previously discussed, CO2 emissions are 
highly dependent on the drive cycle of the vehicle, which does not lend 
itself well to the NTE-based test procedure. Therefore, we propose that 
manufacturers be required to submit CO2 data from in-use 
testing, in both g/bhp-hr and g/ton-mile, but these data will be used 
for reference purposes only (there would be no NTE limit/standard for 
CO2).
(3) Other Certification Provisions
(a) Carryover/Carry Across Certification Test Data
    EPA's current certification program for heavy-duty engines allows 
manufacturers to carry certification test data over and across 
certification testing from one model year to the next, when no 
significant changes to models are made. EPA is proposing to also apply 
this policy to CO2, N2O and CH4 
certification test data.
(b) Certification Fees
    The CAA allows EPA to collect fees to cover the costs of issuing 
certificates of conformity for the classes of engines covered by this 
proposal. On May 11, 2004, EPA updated its fees regulation based on a 
study of the costs associated with its motor vehicle and engine 
compliance program (69 FR 51402). At the time that cost study was 
conducted, the current rulemaking was not considered. At this time the 
extent of any added costs to EPA as a result of this proposal is not 
known. EPA will assess its compliance testing and other activities 
associated with the rule and may amend its fees regulations in the 
future to include any warranted new costs.
(c) Onboard Diagnostics
    Beginning in the 2013 model year, manufacturers will be required to 
equip heavy-duty engines with on-board diagnostic systems. These 
systems monitor the activity of the emission control system and issue 
alerts when faults are detected. These diagnostic systems are currently 
being developed based around components and systems that influence 
criteria pollutant emissions. Consistent with the light-duty vehicle 
GHG rule, we believe that monitoring of these components and systems 
for criteria pollutant emissions will have an equally beneficial effect 
on CO2 emissions. Therefore, we do not anticipate the 
necessity of having any unique onboard diagnostic provisions for heavy-
duty GHG emissions. We are seeking comment on this topic, however.
(d) Applicability of Current High Altitude Provisions to Greenhouse 
Gases
    EPA is proposing that engines covered by this proposal must meet 
CO2, N2O and CH4 standards at elevated 
altitudes. The CAA requires emission standards under section 202 for 
heavy-duty engines to apply at all altitudes. EPA does not expect 
engine CO2, CH4, or N2O emissions to 
be significantly different at high altitudes based on engine 
calibrations commonly used at all altitudes. Therefore, EPA proposes 
that it retain its current high altitude regulations so manufacturers 
will not normally be required to submit engine CO2 test data 
for high altitude. Instead, they will be required to submit an 
engineering evaluation indicating that common calibration approaches 
will be utilized at high altitude. Any deviation in emission control 
practices employed only at altitude will need to be included in the 
AECD descriptions submitted by manufacturers at certification. In 
addition, any AECD specific to high altitude will be required to 
include emissions data to allow EPA evaluate and quantify any emission 
impact and validity of the AECD.
(e) Emission-Related Installation Instructions
    Engine manufacturers are currently required to provide detailed 
installation instructions to vehicle manufacturers. These instructions 
outline how to properly install the engine, aftertreatment, and other 
supporting systems, such that the engine will operate in its certified 
configuration. At the time of certification, manufacturers may be 
required to submit these instructions to EPA to verify that sufficient 
detail has been provided to the vehicle manufacturer.
    We do not anticipate any major changes to this documentation as a 
result of regulating GHG emissions. The most significant impact will be 
the addition of language prohibiting vehicle manufacturers from 
installing engines into vehicle categories in which they are not 
certified for. An example would be a tractor manufacturer installing an 
engine certified for only vocational vehicle use. Explicit instructions 
on behalf of the engine manufacturer that such acts are prohibited will 
serve as sufficient notice to the vehicle manufacturers and failure to 
follow

[[Page 74270]]

such instructions will in the vehicle manufacturer being in non-
compliance.
(f) Alternate CO2 Emission and Fuel Consumption Standards
    Under the proposed rule, engine manufacturers have the option of 
certifying to CO2 emission and fuel consumption standards 
that are 5 percent below a baseline value established from their 2011 
model-year products. If a manufacturer elects to participate in this 
program they must indicate this on their certification application. In 
addition, sufficient details must be submitted regarding the baseline 
engine such that the agency can verify that the correct optional 
CO2 emission and fuel consumption standards have been 
calculated. This data will need to include the engine family name of 
the baseline engine, so references to the original certification 
application can be made, as well as test data showing the 
CO2 emissions and fuel consumption of the baseline engine.

D. Class 7 and 8 Combination Tractors

(1) Proposed Compliance Approach
    In addition to requiring engine manufacturers to certify their 
engines, manufacturers of Class 7 and 8 combination tractors must also 
certify that their vehicles meet the proposed CO2 emission 
and fuel consumption standards. This vehicle certification will ensure 
that efforts beyond just engine efficiency improvements are undertaken 
to reduce GHG emissions and fuel consumption. Some examples include 
aerodynamic improvements, rolling resistance reduction, idle reduction 
technologies, and vehicle speed limiting systems.
    Unlike engine certification however, this certification would be 
based on a load-specific basis (g/ton-mile or gal/1,000 ton-mile as 
opposed to work-based, or g/bhp-hr). This would take into account the 
anticipated vehicle loading that would be experienced in use and the 
associated affects on fuel consumption and CO2 emissions. 
Vehicle manufacturers would also be required to warrant their products 
against emission defects, and demonstrate that a service network is in 
place to correct any such conditions. The vehicle manufacturer also 
bears responsibility in the event that an emission-related recall is 
necessary.
(a) Certification Process
    In order to obtain a certificate of conformity for the tractor, 
vehicle manufacturers would complete a compliance demonstration, 
showing that their product meets emission standards as well as other 
regulatory requirements. For purposes of this demonstration, vehicles 
with similar emission characteristics throughout their useful life are 
grouped together in test groups, similar to EPA's light-duty emissions 
certification program. Examples of characteristics that would define a 
test group for heavy-duty vehicles are wheel and tire package, 
aerodynamic profile, tire rolling resistance, and engine model. Under 
this system, the worst-case vehicle would be selected based on having 
the highest fuel consumption, and all other models within the family 
are assumed to have emissions and fuel consumption at or below the 
parent model and therefore in compliance with CO2 emission 
and fuel consumption standards. Any vehicle within the family can be 
subject to selective enforcement auditing in addition to confirmatory 
or other administrator testing.
    We anticipate test groups for Class 7 and 8 combination tractors to 
utilize the standardized 12-digit naming convention, as outlined in the 
engine certification section of this chapter. As with engines, each 
certifying vehicle manufacturer will have a unique three digit code 
assigned to them. Currently, there is no 5th digit (industry sector) 
code for this class of vehicles, for which we propose to use the next 
available character, ``2.'' Since we are proposing that the engine is 
one of several test-group defining features, we still believe it is 
appropriate to include engine displacement in the family name. If the 
test-group consists includes multiple engine models with varying 
displacements, the largest would be specified in the test-group name, 
consistent with current practices. The remaining characters would 
remain available for California ARB and/or manufacturer use, such that 
the result is a unique test-group name.
    Class 7 and 8 tractors share several common traits, such as the 
trailer attachment provisions, number of wheels, and general 
construction. However, further inspection reveals key differences 
related to GHG emissions. Payloads hauled by Class 7 tractors are 
significantly less than Class 8 tractors. In addition, Class 8 vehicles 
may have provisions for hoteling (``sleeper cabs''), which results in 
an increase in size as well as the addition of comfort features like 
power and climate control for use while the truck is parked. Both 
segments may have various degrees of roof fairing to provide better 
aerodynamic matching to the trailer being pulled. This is a feature 
which can help reduce CO2 emissions significantly when 
properly matched to the trailer, but can also increase CO2 
emissions if improperly matched. Based on these differences, it is 
reasonable to expect differences in CO2 emissions, and 
therefore these properties form the basis for the proposed combination 
tractor regulatory subcategories.
    The various combinations of payload, cab size, and roof profile 
result in nine proposed regulatory subcategories for Class 7 and 8 
trucks. These include Class 7 (day cabs), Class 8 (day cabs), and Class 
8 (sleeper cabs), each with high, mid, and low roof profiles. The Class 
7 tractors would have a regulatory useful life of 185,000 miles while 
Class 8 tractors would have a regulatory life of 435,000 miles and must 
meet CO2 emission standards throughout this period.
(b) Demonstrating Compliance With the Proposed Standards
(i) CO2 and Fuel Consumption Standards
    Consistent with existing certification processes for light-duty 
vehicles and heavy-duty pickups and vans, emissions testing of the 
complete vehicle would be the preferred method for demonstrating 
compliance with vehicle emission standards. However, vehicle-level 
certification is new to the heavy-duty vehicle segment above 14,000 lb. 
Therefore, most vehicle manufacturers are not adequately equipped to 
conduct vehicle-level emission testing for Class 7 and 8 combination 
tractors. Chassis dynamometers, emission sampling equipment, and staff 
engineering support are a few of the factors that would add significant 
cost to vehicle development in a relatively short amount of time, which 
may make the prospect of vehicle testing quite onerous. In addition to 
the infrastructure and testing facilities the industry would need to 
add, the agencies have not completed the extensive work ultimately 
desirable for us to propose new test procedures and standards based on 
the use of a chassis test procedure. Moreover, as explained in Section 
II.C, because of the enormous numbers of truck configurations that have 
an impact on fuel consumption, we do not believe that it would be 
reasonable, at least initially, to require testing of many combinations 
of tractor model configurations on a chassis dynamometer. Recognizing 
these constraints related to time, staffing, and capital, we are 
proposing only a vehicle simulation model option for demonstrating 
compliance at the time of certification. However, we do believe that a 
chassis based test procedure as

[[Page 74271]]

currently utilized for vehicles below 14,000 pounds could be a better 
long-term approach to regulate all heavy-duty vehicles and we are 
seeking comment on a chassis based approach.
Model
    Vehicle modeling will be conducted using the agencies' simulation 
model, GEM, which is described in detail in Chapter 4 of the draft RIA. 
Basically, this model functions by defining a vehicle configuration and 
then exercises the model over various drive cycles. Several 
initialization files are needed to define a vehicle, which include 
mechanical attributes, control algorithms, and driver inputs. The 
majority of these inputs will be predetermined by EPA and NHTSA for the 
purposes of vehicle certification. The net results from GEM are 
CO2 emissions and fuel consumption values over the proposed 
drive cycles. The CO2 emission result will be used for 
demonstrating compliance with vehicle CO2 standards while 
the fuel consumption result will be used for demonstrating compliance 
with the fuel consumption standards.
    The vehicle manufacturer will be responsible for entering 
aerodynamic properties of the vehicle, the weight reduction, tire 
properties, idle reduction systems, and vehicle speed limiting systems. 
For GEM inputs relating to weight reduction and aerodynamics, the 
agencies are proposing the use of lookup tables based on typical 
performance levels across the industry. These lookup tables do not have 
data directly related to CO2, but rather provide the 
appropriate coefficients for the model to assess CO2- and 
fuel consumption-related performance. The agencies will enter the 
appropriate engine map reflecting use of a certified engine in the 
truck (and will enter the same value even if an engine family is 
certified to the temporary percent reduction alternative standard, in 
order to evaluate vehicle performance independently of engine 
performance.) We believe this approach reduces the testing burden 
placed upon manufacturers, yet adequately assesses improvements 
associated with select technologies. The model will be publicly 
available and will be found on EPA's Web site.
    The agency reserves the right to independently evaluate the inputs 
to the model via Administrator testing to validate those model inputs. 
The agency also reserves the right to evaluate vehicle performance 
using the inputs to the model provided by the manufacturer to confirm 
the performance of the system using GEM. This could include generating 
emissions results using the GEM and the inputs as provided by the 
manufacturer based on the agency's own runs. This could also include 
conducting comparable testing to verify the inputs provided by the 
manufacturer. In the event of such testing or evaluation, the 
Administrator's results become the official certification results. The 
exception being that the manufacturer may continue to use their data as 
initially submitted, provided it represents a worst-case condition over 
the Administrator's results.
    To better facilitate the entry of only the appropriate parameters, 
the agencies will provide a graphical user interface in the model for 
entering data specific to each vehicle. This graphical user interface 
allows the end user to avoid interacting directly with the model and 
any associated coding. It is expected that this template will be 
submitted to EPA as part of the certification process for each 
certified vehicle configuration.
    For certification, the model will exercise the vehicle over three 
test cycles; one transient and two steady-state. For the transient 
test, we are proposing to use the heavy-heavy-duty diesel truck (HHDDT) 
transient test cycle, which was developed by the California Air 
Resources Board and West Virginia University to evaluate heavy-duty 
vehicles. The transient mode simulates urban, start-stop driving, 
featuring 1.8 stops per mile over the 2.9 mile duration. The two steady 
state test points are reflective of the tendency for some of these 
vehicles to operate for extended periods at highway speeds. Based on 
data from the EPA's MOVES database, and common highway speed limits, we 
are proposing these two points to be 55 and 65 mph.
    The model will predict the total emissions results from each 
segment using the unique properties entered for each vehicle. These 
results are then normalized to the payload and distance covered, so as 
to yield a gram/ton-mile result, as well as a fuel consumption (gal/
1,000 ton-mile) result for each test cycle. As with engine and vehicle 
testing, certification will be based on a parent rating for the test 
group, representing the worst-case fuel consumption and CO2 
emissions. However, vehicle manufacturers will also have the 
opportunity to model sub-configurations to determine any benefits that 
are available on only a select number of vehicles within a test group.
    The results from all three tests are then combined using weighting 
factors, which reflect typical usage patterns. The typical usage 
characteristics of Class 7 and 8 tractors with day cabs differ 
significantly from Class 8 tractors with sleeper cabs. The trucks with 
day cabs tend to operate in more urban areas, have a limited travel 
range, and tend to return to a common depot at the end of each shift. 
Class 8 sleeper cabs, however, are typically used for long distance 
trips which consist of mostly highway driving in an effort to cover the 
highest mileage in the shortest time. For these reasons, we propose 
that the cycles are weighted differently for these two groups of 
vehicles. For Class 7 and 8 trucks with day cabs, we propose weights of 
64%, 17%, and 19% (65 mph, 55 mph, and transient, resp.). For Class 8 
with sleeper cabs, the high speed cruise tendency results in proposed 
weights of 86%, 9%, and 5% (65 mph, 55 mph, and transient, 
respectively). These final, weighted emission results are compared to 
the emission standard to assess compliance.
Durability Testing
    As with engine certification, a manufacturer must provide evidence 
of compliance through the regulatory useful life of the vehicle. 
Factors influencing vehicle-level GHG performance over the life of the 
vehicle fall into two basic categories: Vehicle attributes and 
maintenance items. Each category merits different treatment from the 
perspective of assessing useful life compliance, as each has varying 
degrees of manufacturer versus owner/operator responsibility.
    The category of vehicle attributes generally refers to aerodynamic 
features, such as fairings, side-skirts, air dams, air foils, etc, 
which are installed by the manufacturer to reduce aerodynamic drag on 
the vehicle. These features have a significant impact on GHG emissions 
and their emission reduction properties are assessed early in the 
useful life (at the time of certification). These features are expected 
to last the full life of the vehicle without becoming detached, 
cracked/broken, misaligned, or otherwise not in the original state. In 
the absence of the aforementioned failure modes, the performance of 
these features is not expected to degrade over time and the benefit to 
reducing GHG emissions is expected to last for the life of the vehicle 
with no special maintenance requirements. To assess useful life 
compliance, we recommend a design-based approach which would ensure 
that the manufacturer has robustly designed these features so they can 
reasonably be expected to last the useful life of the vehicle.
    The category of maintenance items refers to items that are 
replaced, renewed, cleaned, inspected, or otherwise addressed in the 
preventative maintenance schedule specified by the

[[Page 74272]]

vehicle manufacturer. Items that have a direct influence on GHG 
emissions are primarily lubricants. Synthetic engine oil may be used by 
vehicle manufacturers to reduce the GHG emissions of their vehicles. 
Manufacturers may specify that these fluids be changed throughout the 
useful life of the vehicle. If this is the case, the manufacturer 
should have a reasonable basis that the owner/operator will use fluids 
having the same properties. This may be accomplished by requiring (in 
service documentation, labeling, etc) that only these fluids can be 
used as replacements.
    If the vehicle remains in its original certified condition 
throughout its useful life, it is not believed that GHG emissions would 
increase as a result of service accumulation. This is based on the 
assumption that as components wear, the rolling resistance due to 
friction is likely to stay the same or decrease. With all other 
components remaining equal (tires, aerodynamics, etc), the overall drag 
force would stay the same or decrease, thus not significantly changing 
GHG emissions at the end of useful life. It is important to remember 
however, that this vehicle assessment does not take into account any 
engine-related wear affects, which may in fact increase GHG emissions 
over time.
    For the reasons explained above, we believe that for the first 
phase of this program, it is most important to ensure that the vehicle 
remain in its certified configuration throughout the useful life. This 
can most effectively be accomplished through engineering analysis and 
specific maintenance instructions provided by the vehicle manufacturer. 
The vehicle manufacturer would be primarily responsible for providing 
engineering analysis demonstrating that vehicle attributes will last 
for the full life of the vehicle. In addition they will be required to 
submit the recommended maintenance schedule (and other service related 
documentation), showing that fluids meeting original equipment 
properties are required as replacements.
(ii) EPA's Air Conditioning Leakage Standards
    Heavy-duty vehicle air conditioning systems contribute to GHG 
emissions in two ways. First, operation of the air conditioning unit 
places an accessory load on the engine, which increases fuel 
consumption. Second, most modern refrigerants are HFC-based, which have 
significant global warming potential (GWP = 1430). For heavy-duty 
vehicles, the load added by the air conditioning system is 
comparatively small compared to other power requirements of the 
vehicle. Therefore, we are not targeting any GHG reduction due to 
decreased air conditioning usage or higher efficiency A/C units for 
this proposal. However, refrigerant leakage, even in very small 
quantities, can have significant adverse effects on GHG emissions.
    Refrigerant leakage is a concern for heavy-duty vehicles, similar 
to light-duty vehicles. To address this, EPA is proposing a design-
based standard for reducing refrigerant leakage from heavy-duty 
vehicles. This standard is based off using the best practices for 
material selection and interface sealing, as outlined in SAE 
publication J2727. Based on design criteria in this publication, a 
leakage ``score'' can be assessed and an estimated annual leak rate can 
be made for the A/C system based on the refrigerant capacity.
    At the time of certification, manufacturers would be required to 
outline the design of their system, including specifying materials and 
construction methods. They will also need to supply the leakage score 
developed using SAE J2727 and the refrigerant volume of their system to 
determine the leakage rate per year. If the certifying manufacturer 
does not complete installation of the air conditioning unit, detailed 
instructions must be provided to the final installer which ensures that 
the A/C system is assembled to meet the low-leakage standards. These 
instructions will also need to be provided at the time of 
certification, and manufacturers must retain all records relating to 
auditing of the final assembler.
(c) In-Use Standards
    As previously addressed, the drive-cycle dependence of 
CO2 emissions makes NTE-based in-use testing impractical. In 
addition, we believe the reporting of CO2 data from the 
criteria pollutant in-use testing program will be helpful in future 
rulemaking efforts. For these reasons, we are not proposing an NTE-
based in-use testing program for Class 7 and 8 combination tractors 
during this proposal.
    In the absence of NTE-based in-use testing, provisions are 
necessary for verifying that production vehicles are in the certified 
configuration, and remain so throughout the useful life. Perhaps the 
easiest method for doing this is to verify the presence of installed 
emission-related components. This would basically consist of a vehicle 
audit against what is claimed in the certification application. This 
includes verifying the presence of aerodynamic components, such as 
fairings, side-skirts, and gap-reducers. In addition, the presence of 
idle-reduction and speed limiting devices would be verified. The 
presence of LRR tires could be verified at the point of initial sale; 
however verification at other points throughout the useful life would 
be non-enforceable for the reasons mentioned previously.
    The category of wear items primarily relates to tires. It is 
expected that vehicle manufacturers will equip their trucks with LRR 
tires, as they may provide a substantial reduction in GHG emissions. 
The tire replacement intervals for this class of vehicle is normally in 
the range of 50,000 to 100,000 miles, which means the owner/operator 
will be replacing the tires at several points within the useful life of 
the vehicle. We believe that as LRR tires become more common on new 
equipment, the aftermarket prices of these tires will also decrease. 
Along with decreasing tire prices, the fuel savings realized through 
use of LRR tires will ideally provide enough incentive for owner/
operators to continue purchasing these tires. The inventory modeling in 
this proposal reflects the continued use of LRR tires through the life 
of the vehicle. We seek comment on this and all aspects of our 
inventory modeling.
(2) Proposed Enforcement Provisions
    As identified above, a significant amount of vehicle-level GHG 
reduction is anticipated to come from the use of components 
specifically designed to reduce GHG emissions. Examples of such 
components include LRR tires, aerodynamic fairings, idle reduction 
systems, and vehicle speed limiters. At the time of certification, 
vehicle manufacturers will specify which components will be on their 
vehicle when introduced into commerce. Based on this list of components 
reported to EPA the GHG performance of the vehicle will be assessed, 
typically through modeling, and a certificate of conformity may be 
issued. As described in the in-use testing section, it is important to 
have the ability to determine if the vehicle is in the certified 
configuration both at the time of sale, as well as at any point within 
the useful life.
    Perhaps the most practical and basic method of verifying that a 
vehicle is in its certified configuration is through a vehicle 
emissions control information label, similar to that used for engines 
and light-duty vehicles. This label would list identifying features of 
the vehicle, including model year, vehicle model, certified engine 
family, vehicle manufacturer, test group, and GHG emissions category. 
In addition, this label would list emission-related

[[Page 74273]]

components that an inspector could reference in the event of a field 
inspection. Possible examples may include LRR (for LRR tires), ARF 
(aerodynamic roof fairing), and ARM (aerodynamic rearview mirrors). 
With this information, inspectors could verify the presence and 
condition of attributes listed as part of the certified configuration.
    Similarly, on current emission control information labels, 
manufacturers list abbreviations, which are defined in SAE J1930, for 
each emission control device. Examples include three-way catalyst 
(TWC), electronic control (EC), and heated oxygen sensor 
(HO2S). Unfortunately we are not aware of a similar, 
existing list of vehicle emission control devices and features likely 
to be used on heavy-duty vehicles. At this point, it is also difficult 
to develop such a list due to the wide array of devices and features 
vehicle manufacturers may use in the future. Therefore, we are 
currently seeking comment on how to best define a list of emission 
control devices and features for use in this vehicle GHG certification 
label.
    At the time of certification, manufacturers will be required to 
submit an example of their vehicle emission control label such that EPA 
can verify that all critical elements are present. Such elements 
include the vehicle family/test group name, emission control system 
identifiers described above, regulatory sub-category of the vehicle, 
and Family Emission Limits to which the vehicle is certified to. In 
addition to the label, manufacturers will also need to describe where 
the unique vehicle identification number and date of production can be 
found on the vehicle.
(3) Other Certification Provisions
(a) Warranty
    Section 207 of the CAA requires manufacturers to warrant their 
products to be free from defects that would otherwise cause non-
compliance with emission standards. In addition, this warranty must 
ensure that the vehicle remains in this configuration throughout its 
useful life. For purposes of this regulation, vehicle manufacturers 
must warrant all components installed which act to reduce 
CO2 emissions at the time of initial sale. This includes all 
aerodynamic features, tires, idle reduction systems, speed limiting 
system, and other equipment added to reduce CO2 emissions. 
In addition, the manufacturer must ensure these components and systems 
remain functional for the useful life of the vehicle. The exception 
being tires, which are only required to be warranted for the first life 
of the tires (vehicle manufacturers are not expected to cover 
replacement tires). For aerodynamic features, such as fairings or side-
skirts, the manufacturer must warrant against failures which are not 
the result operator damage. However, these components should be 
designed to withstand possible damage from normal driving, which may 
include stone impingement and other minor impact with small debris.
    The vehicle manufacturer is also required to warrant the A/C system 
for the useful life of the vehicle against design or manufacturing 
defects causing refrigerant leakage in excess of the standard.
    At the time of certification, manufacturers must supply a copy of 
the warranty statement that will be supplied to the end customer. This 
document should outline what is covered under the GHG emissions related 
warranty as well as the length of coverage. Customers must also have 
clear access to the terms of the warranty, the repair network, and the 
process for obtaining warranty service.
(b) Maintenance
    Vehicle manufacturers are required to outline maintenance schedules 
that ensure their product will remain in compliance with emission 
standards throughout the useful life of the vehicle. For heavy-duty 
vehicles, such maintenance may include fluid/lubricant service, fairing 
adjustments, or service to the GHG emission control system. This 
schedule is required to be submitted as part of the application for 
certification. Maintenance that is deemed to be critical to ensuring 
compliance with emission standards is classified as ``critical 
emission-related maintenance.'' Generally, manufacturers are 
discouraged from specifying that critical emission-related maintenance 
is needed within the regulatory useful life of the engine. However, if 
such maintenance is unavoidable, manufacturers must have a reasonable 
basis for ensuring it is performed at the correct time. This may be 
demonstrated through several methods including survey data indicating 
that at least 80% of engines receive the required maintenance in-use or 
manufacturers may provide the maintenance at no charge to the user.
(c) Certification Fees
    Similar to engine certification, the agency will assess 
certification fees for heavy-duty vehicles. The proceeds from these 
fees are used to fund the compliance and certification activities 
related to GHG regulation for this regulatory category. In addition to 
the certification process, other activities funded by certification 
fees include EPA-administered in-use testing, selective enforcement 
audits, and confirmatory testing. At this point, the exact costs 
associated with the heavy-duty vehicle GHG compliance are not well 
known. EPA will assess its compliance program associated with this 
proposal and assess the appropriate level of fees. We anticipate that 
fees will be applied based on test groups, following the light-duty 
vehicle approach.
(d) Requirements For Conducting Aerodynamic Assessment Using Allowed 
Methods
    The requirements for conducting aerodynamic assessment using 
allowed methods includes two key components: Adherence to a minimum set 
of standardized criteria for each allowed method and submittal of 
aerodynamic values and supporting information on an annual basis for 
the purposes of certifying vehicles to a particular aerodynamic bin as 
discussed in the Section II.
    First, we are proposing requirements for conducting each of the 
allowed aerodynamic assessment methods. We will cite approved and 
published standards and practices, where feasible, but will attempt to 
propose criteria where none exists or where more current research 
indicates otherwise. We are requesting comment on the proposed 
requirements for each allowed method, standards and practices that 
should be used, and any unique criteria that we are proposing. A 
description of the requirements for each method is discussed later in 
this section. The manufacturer would be required to provide information 
showing that they meet these requirements and attest to the accuracy of 
the information provided.
    Second, to ensure continued compliance, manufacturers would be 
required to provide a minimum set of information on an annual basis at 
certification time (1) to support continued use of an aerodynamic 
assessment method and (2) to assign an aerodynamic value based on the 
applicable aerodynamic bins. The information supplied to the agencies 
should be based on an approved aerodynamic assessment method and adhere 
to the requirements for conducting aerodynamic assessment mentioned 
above.
    Regardless of the method, all testing should be performed with a 
tractor-trailer combination to mimic real world

[[Page 74274]]

usage. Accordingly, it is important to match the type of tractor with 
the correct trailer. Although, as discussed elsewhere in this proposal, 
the correct tractor-trailer combination is not always present or 
tractor-only operation may occur, the majority of operation in the real 
world involves correctly matched tractor-trailer combinations and we 
will attempt to reflect that here. Therefore, the following guidelines 
should be used when performing an aerodynamic assessment:
     For a Class 7 and 8 tractor truck with a low roof, a 
standard flatbed trailer must be used;
     For a Class 7 and 8 tractor truck with a mid roof, a 
standard tanker trailer must be used;
     For a Class 7 and 8 tractor truck with a high roof, a 
standard box trailer must be used.
    The definitions of each standard trailer are proposed in Sec.  
1037.501(g). This ensures consistency and continuity in the aerodynamic 
assessments, and maintains the overlap with real world operation.
Standardized Criteria for Aerodynamic Assessment Methods
(i) Coastdown Procedure Requirements
    For coastdown testing, the test runs should be conducted in a 
manner consistent with SAE J2263 with additional modifications as 
described in the 40 CFR part 1066, subpart C, and in Chapter 3 of the 
draft RIA using the mixed model analysis method. The agencies seek 
comment on the use of these protocols and the modifications that are 
described.
    Since the coastdown procedure is the primary aerodynamic assessment 
method, the manufacturer would be required to conduct the coastdown 
procedure according to the requirements in this proposal and supply the 
following to the agency for approval:
     Facility information: Name and location, description and/
or background/history, equipment and capability, track and facility 
elevation, and track size/length;
     Test conditions for each test result including date and 
time, wind speed and direction, ambient temperature and humidity, 
vehicle speed, driving distance, manufacturer name, test vehicle/model 
type, model year, applicable model engine family, tire type and rolling 
resistance, test weight and driver name(s) and/or ID(s);
     Average Cd result as calculated in 40 CFR 1037.520(b) from 
valid tests including, at a minimum, ten valid test results, with no 
maximum number, standard deviation, calculated error and error bands, 
and total number of tests, including number of voided or invalid tests.
(ii) Wind Tunnel Testing Requirements
    Wind tunnel testing would conform to the following procedures and 
modifications, where applicable, including:
     SAE J1252, ``SAE WIND TUNNEL TEST PROCEDURE FOR TRUCKS AND 
BUSES'' (July 1981) except that article 5.2 that specifies a minimum 
Reynolds number of 0.7 x 10\6\ is not included and is superseded, for 
the purposes of this rulemaking, by a minimum Reynolds number of 1.0 x 
10\6\ and, for reduced-scale wind tunnel testing, a one-eighth (\1/
8\th) or larger scale model of a heavy-duty tractor and trailer must be 
used and of sufficient design to simulate airflow through the radiator 
inlet grill;
     J1594, ``VEHICLE AERODYNAMICS TERMINOLOGY'' (December 
1994); and
     J2071, ``AERODYNAMIC TESTING OF ROAD VEHICLES--OPEN THROAT 
WIND TUNNEL ADJUSTMENT'' (June 1994).
    In addition, the wind tunnel used for aerodynamic assessment would 
be a recognized facility by the Subsonic Aerodynamic Testing 
Association. The agencies seek comment on the use of these protocols 
and the modifications described and the need for membership in this 
testing association.
    For wind tunnel testing, we are proposing that manufacturers 
perform wind tunnel testing and the coastdown procedure, according to 
the requirements proposed in this notice, on the same tractor model and 
provide the results for both methods. The wind tunnel tests should be 
conducted at a zero yaw angle and, if so equipped, utilizing the 
moving/rolling floor (i.e., the moving/rolling floor should be on 
during the test as opposed to static) for comparison to the coastdown 
procedure, which corrects to a zero yaw angle for the oncoming wind. 
The manufacturer would be required to supply the following:
     Facility information: Name and location, description and 
background/history, layout, wind tunnel type, diagram of wind tunnel 
layout, structural and material construction;
     Wind tunnel design details: Corner turning vane type and 
material, air settling, mesh screen specification, air straightening 
method, tunnel volume, surface area, average duct area, and circuit 
length;
     Wind tunnel flow quality: Temperature control and 
uniformity, airflow quality, minimum airflow velocity, flow uniformity, 
angularity and stability, static pressure variation, turbulence 
intensity, airflow acceleration and deceleration times, test duration 
flow quality, and overall airflow quality achievement;
     Test/Working section information: Test section type (e.g., 
open, closed, adaptive wall) and shape (e.g., circular, square, oval), 
length, contraction ratio, maximum air velocity, maximum dynamic 
pressure, nozzle width and height, plenum dimensions and net volume, 
maximum allowed model scale, maximum model height above road, strut 
movement rate (if applicable), model support, primary boundary layer 
slot, boundary layer elimination method and photos and diagrams of the 
test section;
     Fan section description: Fan type, diameter, power, 
maximum rotational speed, maximum tip speed, support type, mechanical 
drive, sectional total weight;
     Data acquisition and control (where applicable): 
Acquisition type, motor control, tunnel control, model balance, model 
pressure measurement, wheel drag balances, wing/body panel balances, 
and model exhaust simulation;
     Moving ground plane or Rolling Road (if applicable): 
Construction and material, yaw table and range, moving ground length 
and width, belt type, maximum belt speed, belt suction mechanism, 
platen instrumentation, temperature control, and steering; and
     Facility correction factors and purpose.
(iii) CFD Requirements
    Currently, there is no existing standard, protocol or methodology 
governing the use of CFD. Therefore, we are coupling the use of CFD 
with empirical measurements from coastdown and wind tunnel procedures. 
However, we think it is important to require a minimum set of criteria 
that all CFD analysis should follow for the purpose of these rules and 
to produce a consistent set of results to maintain compliance. Since 
there are primarily two-types of CFD software code, Navier-Stokes based 
and Lattice-Boltzman based, we are outlining two sets of criteria to 
address both types. Therefore, the agencies propose that manufacturers 
use commercially-available CFD software code with a turbulence model 
enabled and Navier-Stokes formula solver, where applicable. Further 
details and criteria for each type of commercially-available CFD 
software code follows immediately and general criteria for all CFD 
analysis are subsequently described.
    For Navier-Stokes based CFD code, manufacturers must perform an

[[Page 74275]]

unstructured, time-accurate analysis using a mesh grid size with total 
surface elements greater than or equal to 5 million cells/nodes, a 
near-vehicle cell size of less than or equal to 10 millimeters (mm), a 
near-wall cell size of less than or equal to 1mm,\203\ and a volume 
element size of less than or equal to 5 mm; using hexagonal or 
polyhedral mesh cell shapes. All Navier-Stokes based CFD analysis 
should be performed with a k-epsilon (k-[egr]) or a shear stress 
transport k-omega (SST k-[omega]) turbulence model and mesh deformation 
enabled with boundary layer resolution of +/- 95%. Finally, Navier-
Stokes based CFD analysis for the purposes of determining the Cd should 
be performed once result convergence is achieved and manufacturers 
should be able to demonstrate convergence by supplying multiple, 
successive convergence values.
---------------------------------------------------------------------------

    \203\ See Lecture Notes in Applied and Computational Mechanics, 
The Aerodynamics of Heavy Vehicles II: Trucks, Buses, and Trains; 
DOI: 10.1007/978-3-540-85070-0--33; ``Applicability of Commercial 
CFD tools for assessment of heavy vehicle aerodynamic 
characteristics'' as created by the University of Chicago as 
Operator of Argonne National Laboratory (``Argonne'') under contract 
No. W-31-109-ENG-38 with the U.S. Department of Energy.
---------------------------------------------------------------------------

    For Lattice-Boltzman based CFD code, the agencies propose that 
manufacturers perform an unstructured, time-accurate analysis using a 
mesh grid size with total surface elements greater than or equal to 5 
million cells/nodes, a near-vehicle cell size of less than or equal to 
10 millimeters (mm), a near-wall cell size of less than or equal to 
1mm, and a volume element size of less than or equal to 5 mm; using 
cubic volume elements and triangle and/or quadrilateral surface 
elements.
    Finally, in general for CFD, all analysis should be conducted 
assuming zero yaw angle for comparison to the coastdown test procedure. 
In addition, the ambient conditions assumed for the CFD analysis should 
be defined according to the environmental conditions that the 
manufacturer is seeking to simulate. For simulating a wind tunnel test, 
the CFD analysis should accurately model that wind tunnel and assume a 
wind tunnel blockage ratio consistent with SAE J1252 or that matches 
the selected wind tunnel, whichever is lower. For simulation of open 
road conditions similar to that experienced during coastdown test 
procedures, the CFD analysis should assume a blockage ratio of less 
than or equal 0.2%.
    The agencies seek comment on the use of CFD commercial or open 
source code and the criteria set forth above for conducting the 
analysis.
    Finally, in general for each of the allowed aerodynamic assessment 
methods, we are requesting comment on the list of information that must 
be provided for facilities and test conditions.
Annual Testing and Data Submittal for Aerodynamic Assessment
    Once the manufacturer has performed acceptance demonstration, the 
aerodynamic assessment can be used to generate Cd values for all 
vehicle models the manufacturer plans to certify and introduce into 
commerce. For each model, the manufacturer would supply a predicted Cd 
based for each of the other models in the manufacturer's fleet and the 
other conditions used to determine the base Cd. This reduces burden on 
the manufacturer to perform aerodynamic assessment but provides data 
for all the models in a manufacturer's fleet. If a manufacturer has 
previously performed aerodynamic assessment on the other models, the 
manufacturer may submit an experimental Cd in lieu of a predicted Cd.
    The aerodynamic assessment data would be used by the manufacturer 
who would input the Cd value from the look-up table, based on the 
results from the aerodynamic assessment, into GEM and determine a GHG 
emissions and fuel consumption level.
    Since the agency may input the data into the model, manufacturers 
would provide the information described above for acceptance 
demonstration for the purposes of annual certification. In addition, 
the manufacturer would supply manufacturer fleet information to the 
agency for annual certification purposes along with the acceptance 
demonstration parameters: manufacturer name, model year, model line (if 
different than manufacturer name), model name, engine family, engine 
displacement, transmission name and type, number of axles, axle ratio, 
vehicle dimensions, including frontal area, predicted or measured 
coefficient of drag, assumptions used in developing the predicted or 
measured Cd. justification for carry-across of aerodynamic assessment 
data, photos of the model line-up, if available, and model applications 
and usage options.
    We are requesting comment on the annual testing requirements and 
the burden on manufacturers to satisfy the requirements.
(e) Aerodynamic Assessment Validation and Compliance
    Although the procedures above should ensure accuracy in the 
aerodynamic assessment, it is always beneficial to perform confirmation 
or validation post-certification. The agencies would like to ensure a 
level playing field among the manufacturers and the different 
aerodynamic assessment methods. The agencies hope to finalize a method 
for doing so after working through the comments from all stakeholders 
in a collaborative manner.
    The agencies envision that a program for aerodynamic assessment 
could consist of two parts: (1) Validation of the manufacturer source 
data by performing an audit of the manufacturer's aerodynamic 
assessment methods and tools as described in this proposal using a 
reference truck and/or (2) vehicle confirmatory evaluation using a 
vehicle recruited from the in-use fleet and performing the aerodynamic 
assessment discussed in this proposal, either using the manufacturer's 
facility and tools or using the agency's facility and tools. We are 
seeking comment on the all aspects of an aerodynamic assessment 
validation and compliance.

E. Class 2b-8 Vocational Vehicles

(1) Proposed Compliance Approach
    Like Class 7 and 8 combination tractors, heavy-duty vocational 
vehicles would be required to have both engine and complete vehicle 
certificates of conformity. As discussed in the engine certification 
section, engines that will be used in vocational vehicles would need to 
be certified using the Heavy-duty FTP cycle for GHG pollutants and show 
compliance through the useful life of the engine. This certification is 
in addition to the current requirements for obtaining a certificate of 
conformity for criteria pollutant emissions.
    For this proposal, the majority of the GHG reduction for vocational 
vehicles is expected to come from the use of LRR tires as well as 
increased utilization of hybrid powertrain systems. Other technologies 
such as aerodynamic improvements and vehicle speed limiting systems are 
not as relevant for this class of vehicles, since the typical duty 
cycle is much more urban, consisting of lower speeds and frequent 
stopping. Idle reduction strategies are expected to be encompassed by 
hybrid technology, which we anticipate will ultimately handle PTO 
operation. Therefore, for this initial proposal, certification of 
heavy-duty vocational vehicles with conventional powertrains will focus 
on quantifying GHG benefits due to the use of LRR tires.

[[Page 74276]]

(a) Certification Process
    Vehicles would be divided into test groups for purposes of 
certification. As with Class 7 and 8 combination tractors, these are 
groups of vehicles within a given regulatory category that are expected 
to share common emission characteristics. Vocational vehicle regulatory 
subcategories share the same structure as those used for heavy-duty 
engine criteria pollutant certification and are based on GVWR. This 
includes light-heavy (LHD) with a GVWR at or below 19,500 pounds, 
medium-heavy (MHD) with a GVWR above 19,500 pounds and at or below 
33,000 pounds, and heavy-heavy (HHD) with a GVWR above 33,000 pounds. 
Other test group features may include the type of tires used, intended 
application, and number of wheels.
    As with Class 7 and 8 combination tractors, we anticipate using the 
standardized 12-digit naming convention to identify vocational vehicle 
test groups. As with engines and Class 7 and 8 combination tractors, 
each certifying vehicle manufacturer would have a unique three digit 
code assigned to them. Currently, there is no 5th digit (industry 
sector) code for this class of vehicles, for which we propose to use 
the next available character, ``3.'' Since we are proposing that the 
engine is one of several test-group defining features, we still believe 
it is appropriate to include engine displacement in the family name. If 
the test-group consists includes multiple engine models with varying 
displacements, the largest would be specified in the test-group name, 
consistent with current practices. The remaining characters would 
remain available for California ARB and/or manufacturer use, such that 
the result is a unique test-group name.
    Each test group would need to demonstrate compliance with emission 
standards using the GEM approach. Additional provisions are available 
for certification of hybrid vehicles or vehicles using unique 
technologies, which was detailed in Section IV. If the test group 
consists of multiple models, only result from the worst-case model is 
necessary for certification. However, manufacturers would need to 
submit an engineering evaluation demonstrating that the test group has 
been assembled appropriately and that the test model indeed reflects 
the worst-case model. Also, manufacturers should plan on submitting 
tire rolling resistance properties to EPA at the time of certification. 
Finally the data from each of the certification cycles described below 
will need to be submitted at the time of certification.
(b) Demonstrating Compliance With the Proposed Standards
(i) CO2 and Fuel Consumption Standards
Model
    For this proposal, the agencies are proposing that demonstrating 
compliance with GHG and fuel consumption standards would primarily 
involve demonstrating the use of LRR tires and quantifying the 
associated CO2 and fuel consumption benefit. Similar to 
Class 7 and 8 combination tractors, this will be done using GEM. 
However, the input parameters entered by the vehicle manufacturer would 
be limited to the properties of the tires. GEM will use the tire data, 
along with inputs reflecting a baseline truck and engine, to generate a 
complete vehicle model. The test weight used in the model will be based 
on the vehicle class, as identified above. Light-heavy-duty vehicles 
will have a test weight of 16,000 pounds; 25,150 pounds for medium 
heavy-duty vehicles; and heavy heavy-duty vocational vehicles will use 
a test weight of 67,000 pounds. The model would then be exercised over 
the HHDDT transient cycle as well as 55 and 65 mph steady-state cruise 
conditions. The results of each of the three tests would be weighted at 
37%, 21%, and 42% for 65 mph, 55 mph, and transient tests, 
respectively.
    It may seem more expedient and just as accurate to require 
manufacturers use tires meeting certain industry standards for 
qualifying tires as having LRR. In addition, CO2 and fuel 
consumption benefits could be quantified for different ranges of 
coefficients of rolling resistance to provide a means for comparison to 
the standard. However, we believe that as technology advances, other 
aspects of vocational vehicles may warrant inclusion in future 
rulemakings. For this reason, we believe it is important to have the 
certification framework in place to accommodate such additions. While 
the modeling approach may seem to be overly complicated for this phase 
of the rules, it also serves to create a certification pathway for 
future rulemakings and therefore we believe this is the best approach. 
Should innovative technologies be considered that are currently beyond 
the scope of the model, it would be necessary for the manufacturer to 
conduct A to B testing which reflects the improvement associated with 
the new technology. The test protocol to be used and the basis of this 
assessment will require a public vetting process which would likely 
include notice and comment.
In-use Standards
    The category of wear items primarily relates to tires. It is 
expected that vehicle manufacturers will equip their trucks with LRR 
(LRR) tires, since the proposed vehicle standard is predicated on LRR 
tires' performance. The tire replacement intervals for this class of 
vehicle is normally in the range of 50,000 to 100,000 miles, which 
means the owner/operator will be replacing the tires at several points 
within the useful life of the vehicle. We believe that as LRR tires 
become more common on new equipment, the aftermarket prices of these 
tires will also decrease. Along with decreasing tire prices, the fuel 
savings realized through use of LRR tires will ideally provide enough 
incentive for owner/operators to continue purchasing these tires. The 
inventory modeling in this proposal reflects the continued use of LRR 
tires through the life of the vehicle. We seek comment on this and all 
aspects of our inventory modeling.
(ii) Evaporative Emission Standards
    Evaporative and refueling emissions from heavy-duty highway engines 
and vehicles are currently regulated under 40 CFR part 86. Even though 
these emission standards apply to the same engines and vehicles that 
must meet exhaust emission standards, we require a separate certificate 
for complying with evaporative and refueling emission standards. An 
important related point to note is that the evaporative and refueling 
emission standards always apply to the vehicle, while the exhaust 
emission standards may apply to either the engine or the vehicle. For 
vehicles other than pickups and vans, the standards proposed in this 
notice to address greenhouse gas emissions apply separately to engines 
and to vehicles. Since we plan to apply both greenhouse gas standards 
and evaporative/refueling emission standards to vehicle manufacturers, 
we believe it would be advantageous to have the regulations related to 
their certification requirements written together as much as possible. 
EPA regards these proposed changes as discrete, minimal, and for the 
most part clarifications to the existing standards. Except as 
specifically proposed here, EPA is not soliciting comment on, or 
otherwise considering whether to make changes to those standards. 
Accordingly, EPA will not consider any comments directed to any aspect 
of these standards other than those specifically proposed here.
    We are generally not proposing to change the evaporative or 
refueling emission standards, but we have come

[[Page 74277]]

across several provisions that warrant clarification or correction:
     When adopting the most recent evaporative emission change 
we did not carry through the changes to the regulatory text applying 
evaporative emission standards for methanol-fueled compression-ignition 
engine. The proposed regulations correct this by applying the new 
standards to all fuels that are subject to standards.
     We are proposing provisions to address which standards 
apply when an auxiliary (nonroad) engine is installed in a motor 
vehicle, which is currently not directly addressed in the highway 
regulation. The proposed approach would require testing complete 
vehicles with any auxiliary engines (and the corresponding fuel-system 
components). Incomplete vehicles would be tested without the auxiliary 
engines, but any such engines and the corresponding fuel-system 
components would need to meet the standards that apply under our 
nonroad program as specified in 40 CFR part 1060.
     We are proposing to remove the option for secondary 
vehicle manufacturers to use a larger fuel tank capacity than is 
specified by the certifying manufacturer without re-certifying the 
vehicle. Secondary vehicle manufacturers needing a greater fuel tank 
capacity would need to either work with the certifying manufacturer to 
include the larger tank, or go through the effort to re-certify the 
vehicle itself. Our understanding is that this provision has not been 
used and would be better handled as part of certification rather than 
managing a separate process. We are proposing corresponding changes to 
the emission control information label.
     Rewriting the regulations in a new part in conjunction 
with the greenhouse gas standards allows for some occasions of improved 
organization and clarity, as well as updating various provisions. For 
example, we are proposing a leaner description of evaporative emission 
families that does not reference sealing methods for carburetors or air 
cleaners. We are also clarifying how evaporative emission standards 
affect engine manufacturers and proposing more descriptive provisions 
related to certifying vehicles above 26,000 pounds GVWR using 
engineering analysis.
     Since we adopted evaporative emission standards for 
gaseous-fuel vehicles, we have developed new approaches for design-
based certification (see, for example, 40 CFR 1060.240). We request 
comment on changing the requirements related to certifying gaseous-fuel 
vehicles to design-based certification. This would allow for a simpler 
assessment for certifying these vehicles without changing the standards 
that apply.
(2) Proposed Labeling Provisions
    It is crucial that a means exist for allowing field inspectors to 
identify whether a vehicle is certified, and if so, whether it is in 
the certified configuration. As with engines and tractors, we believe 
an emission control information label is a logical first step in 
facilitating this identification. For vocational vehicles, the engine 
will have a label that is permanently affixed to the engine and 
identify the engine as certified for use in a certain regulatory 
subcategory of vehicle (i.e., MHD, etc.).
    The vehicle will also have a label listing the test group, engine 
family, and range of tire rolling resistances that the vehicle is 
certified to use. In addition, if any other emission related components 
are present, such as hybrid powertrains, key components will also need 
to be specified on the label. Like the engine label, this will need to 
be permanently affixed to the vehicle in an area that is clearly 
accessible to the owner/operator.
    At the time of certification, manufacturers will be required to 
submit an example of their vehicle emission control label such that EPA 
can verify that all critical elements are present. Such elements 
include the vehicle family/test group name, emission control system 
identifiers described above, regulatory sub-category of the vehicle, 
and Family Emission Limits to which the vehicle is certified to. In 
addition to the label, manufacturers will also need to describe where 
the unique vehicle identification number and date of production can be 
found on the vehicle.
(3) Other Certification Issues
Warranty
    As with other heavy-duty engine and vehicle regulatory categories, 
vocational vehicle chassis manufacturers would be required to warrant 
their product to be free from defects that would adversely affect 
emissions. This warranty also covers the failure of emission related 
components for the useful life of the vehicle. For vocational chassis, 
the key emission related component addressed in this proposal is the 
tires.
    Manufacturers of chassis for vocational vehicles would be required 
to warrant tires to be free from defects at the time of initial sale. 
As with Class 7 and 8 combination tractors, we expect the chassis 
manufacturer to only warrant tires the original tires against 
manufacturing or design-related defects. This tire warranty would not 
cover replacement tires or damage from road hazards or improper 
inflation.
    As with Class 7 and 8 combination tractors, all warranty 
documentation would be submitted to EPA at the time of certification. 
This should include the warranty statement provided to the owner/
operator, description of the service repair network, list of covered 
components (both conventional and high-cost), and length of coverage.
EPA Certification Fees
    Similar to engine and tractor-trailer vehicle certification, the 
agency will assess certification fees for vocational vehicles. The 
proceeds from these fees are used to fund the compliance and 
certification activities related to GHG regulation for this industry 
segment. In addition to the certification process, other activities 
funded by certification fees include EPA-administered in-use testing, 
selective enforcement audits, and confirmatory testing. At this point, 
the exact costs associated with the heavy-duty vehicle GHG compliance 
are not well known. EPA will assess its compliance program associated 
with this proposal and assess the appropriate level of fees. We 
anticipate that fees will be applied based on test groups, following 
the light-duty vehicle approach.
Maintenance
    Vehicle manufacturers are required to outline maintenance schedules 
that ensure their product will remain in compliance with emission 
standards throughout the useful life of the vehicle. For heavy-duty 
vehicles, such maintenance may include fluid/lubricant service, fairing 
adjustments, or service to the GHG emission control system. This 
schedule is required to be submitted as part of the application for 
certification. Maintenance that is deemed to be critical to ensuring 
compliance with emission standards is classified as ``critical 
emission-related maintenance.'' Generally, manufacturers are 
discouraged from specifying that critical emission-related maintenance 
is needed within the regulatory useful life of the engine. However, if 
such maintenance is unavoidable, manufacturers must have a reasonable 
basis for ensuring it is performed at the correct time. This may be 
demonstrated through several methods including survey data indicating 
that at least 80% of engines receive the required maintenance in-use or 
manufacturers may provide the maintenance at no charge to the user.

[[Page 74278]]

F. General Regulatory Provisions

(1) Statutory Prohibited Acts
    Section 203 of the CAA describes acts that are prohibited by law. 
This section and associated regulations apply equally to the greenhouse 
gas standards as to any other regulated emission. Acts that are 
prohibited by section 203 of the CAA include the introduction into 
commerce or the sale of an engine or vehicle without a certificate of 
conformity, removing or otherwise defeating emission control equipment, 
the sale or installation of devices designed to defeat emission 
controls, and other actions. In addition, vehicle manufacturers, or any 
other party, may not make changes to the certified engine that would 
result in it not being in the certified configuration.
    EPA proposes to apply Sec.  86.1854-12 to heavy-duty vehicles and 
engines; this codifies the prohibited acts spelled out in the statute. 
Although it is not legally necessary to repeat what is in the CAA, EPA 
believes that including this language in the regulations provides 
clarity and improves the ease of use and completeness of the 
regulations. Since this change merely codifies provisions that already 
apply, there is no burden associated with the change.
(2) Regulatory Amendments Related to Heavy-Duty Engine Certification
    We are proposing to adopt the new engine-based greenhouse gas 
standards in 40 CFR part 1036 and the new vehicle-based standards in 40 
CFR part 1037. We are proposing to continue to rely on 40 CFR parts 85 
and 86 for conventional certification and compliance provisions related 
to criteria pollutants, but the proposed regulations include a variety 
of amendments that would affect the provisions that apply with respect 
to criteria pollutants. We are not intending to change the stringency 
of, or otherwise substantively change any existing standards.
    The introduction of new parts in the CFR is part of a long-term 
plan to migrate all the regulatory provisions related to highway and 
nonroad engine and vehicle emissions to a portion of the CFR called 
Subchapter U, which consists of 40 CFR parts 1,000 through 1299. We 
have already adopted emission standards, test procedures, and 
compliance provisions for several types of engines in 40 CFR parts 1033 
through 1074. We intend eventually to capture all the regulatory 
requirements related to heavy-duty highway engines and vehicles in 
these new parts. Moving regulatory provisions to the new parts allows 
us to publish the regulations in a way that is better organized, 
reflects updates to various certification and compliance procedures, 
provides consistency with other engine programs, and is written in 
plain language. We have already taken steps in this direction for 
heavy-duty highway engines by adopting the engine-testing procedures in 
40 CFR part 1065 and the provisions for selective enforcement audits in 
40 CFR part 1068.
    EPA solicits comment on these proposed drafting changes and 
additions. This solicitation relates solely to the appropriate 
migration, translation, and enhancement of existing provisions. EPA is 
not soliciting comment on the substance of these existing rules, and is 
not proposing to amend, reconsider, or otherwise re-examine these 
provisions' substantive effect.
    The rest of this section describes the most significant of these 
proposed redrafting changes. The proposal includes several changes to 
the certification and compliance procedures, including the following:
     We propose to require that engine manufacturers provide 
installation instructions to vehicle manufacturers (see Sec.  
1036.130). We expect this is already commonly done; however, the 
regulatory language spells out a complete list of information we 
believe is necessary to properly ensure that vehicle manufacturers 
install engines in a way that is consistent with the engine's 
certificate of conformity.
     Sec.  1036.30, Sec.  1036.250, and Sec.  1036.825 spell 
out several detailed provisions related to keeping records and 
submitting information to us.
     We wrote the greenhouse gas regulations to divide heavy-
duty engines into ``spark-ignition'' and ``compression-ignition'' 
engines, rather than ``Otto-cycle'' and ``diesel'' engines, to align 
with our terminology in all our nonroad programs. This will likely 
involve no effective change in categorizing engines except for natural 
gas engines. To address this concern, we would include a provision in 
Sec.  1036.150 to allow manufacturers to meet standards for spark-
ignition engines if they were regulated as Otto-cycle engines in 40 CFR 
part 86, and vice versa.
     Sec.  1036.205 describes a new requirement for imported 
engines to describe the general approach to importation (such as 
identifying authorized agents and ports of entry), and identifying a 
test lab in the United States where EPA can perform testing on 
certified engines. These steps are part of our ongoing effort to ensure 
that we have a compliance and enforcement program that is as effective 
for imported engines as for domestically produced engines. We have 
already adopted these same provisions for several types of nonroad 
engines.
     Sec.  1036.210 specifies a process by which manufacturers 
are able to get preliminary approval for EPA decisions for questions 
that require lead time for preparing an application for certification. 
This might involve, for example, preparing a plan for durability 
testing, establishing engine families, identifying adjustable 
parameters, and creating a list of scheduled maintenance items.
     Sec.  1036.225 describes how to amend an application for 
certification.
     We are proposing to apply the exemption and recall 
provisions as written in 40 CFR part 1068 instead of the comparable 
provisions in 40 CFR part 85. This involves only minor changes relative 
to current practice.
    We are aware that it may be appropriate to move several additional 
provisions in 40 CFR parts 85 and 86 to subchapter U. For example, 
highway engine manufacturers may find it preferable to use the same 
parameters specified for defining nonroad engine families for 
certifying highway engines. To the extent that the nonroad provisions 
would apply appropriately for highway engines, we and the manufacturers 
would benefit from a consistent approach to certifying both types of 
engines in a way that does not compromise the degree of emission 
control achieved under the existing standards.
    Another area of particular interest is defect reporting. Existing 
regulations require manufacturers to report defects to EPA whenever the 
same defect occurs at least 25 times. This approach can be somewhat 
onerous for manufacturers making high-volume products. For example, for 
an engine model with annual sales above 25,000, this represents a 
defect rate of less than 0.1 percent. In contrast, the approach to 
defect reporting in Sec.  1068.501 accommodates the high sales volumes 
associated with highway engines, basing requirements on a percentage of 
defective products, rather than setting a fixed number for all engine 
families. This flexibility is paired with the explicit direction for 
the manufacturer to actively monitor warranty claims, customer 
complaints, and other sources of information to evaluate and track 
potential defects. We believe this aligns both with the manufacturers' 
interest in producing quality products and EPA's interest in addressing 
any quality concerns that arise from the need to repair in-use engines 
and vehicles.

[[Page 74279]]

(3) Test Procedures For Measuring Emissions From Heavy-Duty Vehicles
    We are proposing a new part 1066 that would contain a general 
chassis-based test procedures in for measuring emissions from a variety 
of vehicles, including vehicles over 14,000 pounds GVWR. However, we 
are not proposing to apply these procedures broadly at this time. The 
test procedures in 40 CFR part 86 would continue to apply for vehicles 
under 14,000 pounds GVWR. Rather, the proposed part 1066 procedures 
would apply only for any testing that would be required for larger 
vehicles. This could include ``A to B'' hybrid vehicle testing and 
coastdown testing. Nevertheless, we will likely consider in the future 
applying these procedures also for other heavy-duty vehicle testing and 
for light-duty vehicles, highway motorcycles, and/or nonroad 
recreational vehicles that rely on chassis-based testing.
    As noted above, engine manufacturers are already using the test 
procedures in 40 CFR part 1065 instead of those originally adopted in 
40 CFR part 86. The new procedures are written to apply generically for 
any type of engine and include the current state of technology for 
measurement instruments, calibration procedures, and other practices. 
We are proposing the chassis-based test procedures in part 1066 to have 
a similar structure.
    The proposed procedures in part 1066 reference large portions of 
part 1065 to align test specifications that apply equally to engine-
based and vehicle-based testing, such as CVS and analyzer 
specifications and calibrations, test fuels, calculations, and 
definitions of many terms. Since several highway engine manufacturers 
were involved in developing the full range of specified procedures in 
part 1065, we are confident that many of these provisions are 
appropriate without modification for vehicle testing.
    The remaining test specifications needed in part 1066 are mostly 
related to setting up, calibrating, and operating a chassis 
dynamometer. This also includes the coastdown procedures that are 
required for establishing the dynamometer load settings to ensure that 
the dynamometer accurately simulates in-use driving.
    Current testing requirements related to dynamometer specifications 
rely on a combination of regulatory provisions, EPA guidance documents, 
and extensive know-how from industry experience that has led to a good 
understanding of best practices for operating a vehicle in the 
laboratory to measure emissions. We attempted in this proposal to 
capture this range of material, organizing these specifications and 
verification and calibration procedures to include a complete set of 
provisions to ensure that a dynamometer meeting these specifications 
would allow for carefully controlled vehicle operation such that 
emission measurements are accurate and repeatable. We request comment 
on the range of proposed requirements related to designing, building, 
and operating chassis dynamometers. For example, we believe that the 
proposed verification and calibration procedures in part 1066, subpart 
B, for diameter, speed, torque, acceleration, base inertia, friction 
loss, and other parameters are all necessary to ensure proper 
dynamometer operation. It may be that some of these checks are 
redundant, or could be achieved with different procedures. There may 
also be additional checks needed to remove possibilities for inadequate 
accuracy or precision.
    The procedures are written with the understanding that heavy-duty 
highway manufacturers have, and need to have, single-roll electric 
dynamometers for testing. We are aware that this is not the case for 
other applications, such as all-terrain vehicles. We are not adopting 
specific provisions for testing with hydrokinetic dynamometers, we are 
already including a provision acknowledging that we may approve the use 
of dynamometers meeting alternative specifications if that is 
appropriate for the type of vehicle being tested and for the level of 
stringency represented by the corresponding emission standards.
    Drafting a full set of test specifications highlights the mixed use 
of units for testing. Some chassis-based standards and procedures are 
written based largely on the International System of Units (SI), such 
as gram per kilometer (g/km) standards and kilometers per hour (kph) 
driving, while others are written based largely on English units (g/
mile standards and miles per hour driving). The proposal includes a mix 
of SI and English units with instructions about converting units 
appropriately. However, most of the specifications and examples are 
written in English units. While this seems to be the prevailing 
practice for testing in the United States, we understand that vehicle 
testing outside the United States is almost universally done in SI 
units. In any case, dynamometers are produced with the capability of 
operating in either English or SI units. We believe there would be a 
substantial advantage toward the goal of achieving globally harmonized 
test procedures if we would write the test procedures based on SI 
units. This would also in several cases allow for more straightforward 
calculations, and reduced risk of rounding errors. For comparison, part 
1065 is written almost exclusively in SI units. We request comment on 
the use of units throughout part 1066.
    A fundamental obstacle toward using SI units is the fact that some 
duty cycles are specified based on speeds in miles per hour. To address 
this, it would be appropriate to convert the applicable driving 
schedules to meter-per-second (m/s) values. Converting speeds to the 
nearest 0.01 m/s would ensure that the prescribed driving cycle does 
not change with respect to driving schedules that are specified to the 
nearest 0.1 mph. The regulations would include the appropriate mph (or 
kph) speeds to allow for a ready understanding of speed values (see 40 
CFR part 1037, Appendix I). This would, for example, allow for drivers 
to continue to follow a mph-based speed trace. The  2 mph 
tolerance on driving speeds could be converted to  1.0 m/s, 
which corresponds to an effective speed tolerance of  2.2 
mph. This may involve a tightening or loosening of the existing speed 
tolerance, depending on whether manufacturers used the full degree of 
flexibility allowed for a mph tolerance value that is specified without 
a decimal place. Similarly, the Cruise cycles for heavy-duty vehicles 
could be specified as 24.5  0.5 m/s (54.8  1.1 
mph) and 29.0  0.5 m/s (64.9  1.1 mph).

G. Penalties

    As part of the fuel efficiency improvement program to be created 
through this rulemaking, NHTSA is proposing civil penalties for non-
compliance with fuel consumption standards. NHTSA's authority under 
EISA, as codified at 49 U.S.C. 32902(k), requires the agency to 
determine appropriate measurement metrics, test procedures, standards, 
and compliance and enforcement protocols for HD vehicles. NHTSA 
interprets its authority to develop an enforcement program to include 
the authority to determine and assess civil penalties for non-
compliance, that would impose penalties determined based on the 
discussion that follows.
    NHTSA proposes that in cases of non-compliance, the agency would 
establish civil penalties based on consideration of the following 
factors:
     Actual fuel consumption performance related to the 
applicable standard.
     Estimated cost to comply with the regulation and 
applicable standard.

[[Page 74280]]

     Quantity of vehicles or engines not complying.
     Manufacturer's history of non-compliance.
     The civil penalty should act as a deterrent.
     The financial condition of the manufacturer.
     Civil penalties paid for non-compliance of the same 
vehicles under the EPA GHG program.
    NHTSA recognizes that EPA also has authority to impose civil 
penalties for non-compliance with GHG regulations. It is not the intent 
of either agency to impose duplicative civil penalties, and in the case 
of non-compliance with fuel consumption regulations, NHTSA intends to 
give consideration to civil penalties imposed by EPA for GHG non-
compliance, as EPA would give consideration to civil penalties imposed 
by NHTSA in the case of non-compliance with GHG regulations.\204\
---------------------------------------------------------------------------

    \204\ EPA discussed a similar situation concerning consideration 
of civil penalties imposed by NHTSA for CAFE violations for light-
duty vehicles, in the final rule establishing the 2012-2016 MY 
standards. See 75 FR 25324 and 25482, May 7, 2010.
---------------------------------------------------------------------------

    The proposed civil penalty amount NHTSA could impose would not 
exceed the limit that EPA is authorized to impose under the CAA. The 
potential maximum civil penalty for a manufacturer would be calculated 
as follows in Equation V-1:

Equation V-1: Aggregate Maximum Civil Penalty

Aggregate Maximum Civil Penalty for a Non-Compliant Regulatory Category 
= (CAA Limit) x (production volume within the regulatory category)

    NHTSA seeks comments related to this proposal for a civil penalty 
program under EISA.
    EPA has occasionally in the past conducted rulemakings to provide 
for nonconformance penalties--monetary penalties that allow a 
manufacturer to sell engines or vehicles that do not meet an emissions 
standard. Nonconformance penalties are authorized for heavy-duty 
engines and vehicles under section 206(g) of the CAA. Three basic 
criteria have been established by rulemaking for determining the 
eligibility of emissions standards for nonconformance penalties in any 
given model year: (1) The emissions standard in question must become 
more difficult to meet, (2) substantial work must be required in order 
to meet the standard, and (3) a technological laggard must be likely to 
develop (40 CFR 86.1103-87). A technological laggard is a manufacturer 
who cannot meet a particular emissions standard due to technological 
(not economic) difficulties and who, in the absence of nonconformance 
penalties, might be forced from the marketplace. The process to 
determine if these criteria are met and to establish penalty amounts 
and conditions is carried out via rulemaking, as required by the CAA. 
The CAA (in section 205) also lays out requirements for the assessment 
of civil penalties for noncompliance with emissions standards.
    As discussed in detail in Section III, the agencies have determined 
that the proposed GHG and fuel consumption standards are readily 
feasible, and we do not believe a technological laggard will emerge in 
any sector covered by these proposed standards. In addition to the 
standards being premised on use of already-existing, cost-effective 
technologies, there are a number of flexibilities and alternative 
standards built into the proposal. However, we do request comment 
regarding this assessment and on whether or not it would be appropriate 
for EPA and NHTSA to initiate rulemaking activity to set nonconformance 
penalties for the proposed standards, subject to their respective 
statutory authorities. Should nonconformance penalties be warranted, 
the benefits of establishing them would be threefold: (1) The EPA and 
NHTSA programs would continue to be equivalent, allowing manufacturers 
to sell the same vehicles and engines to satisfy both programs, (2) 
competitiveness in the affected HD sector would be maintained, 
preserving jobs and consumer choices, and (3) nonconformance penalties 
would be set through a transparent public process, involving notice and 
public hearing.

VI. How would this proposed program impact fuel consumption, GHG 
emissions, and climate change?

A. What methodologies did the agencies use to project GHG emissions and 
fuel consumption impacts?

    EPA and NHTSA used EPA's official mobile source emissions inventory 
model named Motor Vehicle Emissions Simulator (MOVES2010),\205\, to 
estimate emission and fuel consumption impacts of these proposed rules. 
MOVES has capability to take in user inputs to modify default data to 
better estimate emissions for different scenarios, such as different 
regulatory alternatives, state implementation plans (SIPs), geographic 
locations, vehicle activity, and microscale projects.
---------------------------------------------------------------------------

    \205\ MOVES homepage: http://www.epa.gov/otaq/models/moves/index.htm. Version MOVES2010 was used for emissions impacts analysis 
for this proposal. Current version as of September 14, 2010 is an 
updated version named MOVES2010a, available directly from the MOVES 
homepage. To replicate results from this proposal, MOVES2010 must be 
used.
---------------------------------------------------------------------------

    The agencies performed multiple MOVES runs to establish reference 
case and control case emission inventories and fuel consumption values. 
The agencies ran MOVES with user input databases that reflected 
characteristics of the proposed rules, such as emissions improvements 
and recent sales projections. Some post-processing of the model output 
was required to ensure proper results. The agencies ran MOVES for non-
GHGs, CO2, CH4, and N2O for calendar 
years 2005, 2018, 2030, and 2050. Additional runs were performed for 
just the three greenhouse gases and for fuel consumption for every 
calendar year from 2014 to 2050, inclusive, which fed the economy-wide 
modeling, monetized benefits estimation, and climate impacts analysis.
    The agencies also used MOVES to estimate emissions and fuel 
consumption impacts for the other alternatives considered and described 
in Section IX.

B. MOVES Analysis

(1) Inputs and Assumptions
(a) Reference Run Updates
    Since MOVES2010 vehicle sales and activity data were developed from 
AEO2006, EPA first updated these data using sales and activity 
estimates from AEO2010. EPA also updated the fuel supply information in 
MOVES to reflect a 100% E10 ``gasoline'' fuel supply to reflect the 
Renewable Fuels Standard.\206\ MOVES2010 defaults were used for all 
other parameters to estimate the reference case emissions inventories.
---------------------------------------------------------------------------

    \206\ Renewable Fuels Standard available at http://www.epa.gov/otaq/fuels/renewablefuels/index.htm.
---------------------------------------------------------------------------

(b) Control Run Updates
    EPA developed additional user input data for MOVES runs to estimate 
control case inventories. To account for improvements of engine and 
vehicle efficiency, EPA developed several user inputs to run the 
control case in MOVES. Since MOVES does not operate based on Heavy-duty 
FTP cycle results, EPA used the percent reduction in engine 
CO2 emissions expected due to the proposed rules to develop 
energy inputs for the control case runs. Also, EPA used the percent 
reduction in aerodynamic drag coefficient and tire rolling resistance 
coefficient expected from the proposed rules to develop road load input 
for the control case. The fuel supply update used in the reference case 
was used in the control case. Details of all the MOVES runs, input

[[Page 74281]]

data tables, and post-processing are available in the docket (EPA-HQ-
OAR-2010-0162).
    Table VI-1 and Table VI-2 describe the estimated expected 
reductions from these proposed rules, which were input into MOVES for 
estimating control case emissions inventories.
[GRAPHIC] [TIFF OMITTED] TP30NO10.049

    Since nearly all HD pickup trucks and vans will be certified on a 
chassis dynamometer, the CO2 reductions for these vehicles 
will not be represented as engine and road load reduction components, 
but total vehicle CO2 reductions. These estimated reductions 
are described in Table VI-3.
---------------------------------------------------------------------------

    \207\ Section II discusses an alternative engine standard 
proposed for the HD diesel engines in the 2014, 2015, and 2016 model 
years. To the extent that engines using this alternative would be 
expected to have baseline emissions greater than the industry 
average, the reduction from the industry average projected in this 
proposal could be reduced.
[GRAPHIC] [TIFF OMITTED] TP30NO10.050


[[Page 74282]]



(C) What are the projected reductions in fuel consumption and GHG 
emissions?

    EPA and NHTSA expect significant reductions in GHG emissions and 
fuel consumption from these proposed rules--emission reductions from 
both downstream (tailpipe) and upstream (fuel production and 
distribution) sources, and fuel consumption reductions from more 
efficient vehicles. Increased vehicle efficiency and reduced vehicle 
fuel consumption would also reduce GHG emissions from upstream sources. 
The following subsections summarize the GHG emissions and fuel 
consumption reductions expected from these proposed rules.
(1) Downstream (Tailpipe)
    EPA used MOVES to estimate downstream GHG inventories from these 
proposed rules. We expect reductions in CO2 from all heavy-
duty vehicle categories. The reductions come from engine and vehicle 
improvements. EPA expects CH4 and N2O emissions 
to increase very slightly because of a rebound in vehicle miles 
traveled (VMT) and because significant vehicle reductions of these two 
GHGs are not expected from these proposed rules. Overall, downstream 
GHG emissions will be reduced significantly, and is described in the 
following subsections.
    For CO2 and fuel consumption, the total energy 
consumption ``pollutant'' was run in MOVES rather than CO2 
itself. The energy was converted to fuel consumption based on fuel 
heating values assumed in the Renewable Fuels Standard and used in the 
development of MOVES emission and energy rates. These values are 
117,250 kJ/gallon for E10 \208\ and 138,451 kJ/gallon for diesel.\209\ 
To calculate CO2, the agencies assumed a CO2 
content of 8,576 g/gallon for E10 and 10,180 g/gallon for diesel. Table 
VI-4 shows the fleet-wide GHG reductions and fuel savings from 
reference case to control case through the lifetime of model year 2014 
through 2018 heavy-duty vehicles. Table VI-5 shows the downstream GHG 
emissions reductions and fuel savings in 2018, 2030, and 2050.
---------------------------------------------------------------------------

    \208\ Renewable Fuels Standards assumptions of 115,000 BTU/
gallon gasoline (E0) and 76,330 BTU/gallon ethanol (E100) weighted 
90% and 10%, respectively, and converted to kJ at 1.055 kJ/BTU.
    \209\ MOVES2004 Energy and Emission Inputs. EPA420-P-05-003, 
March 2005. http://www.epa.gov/otaq/models/ngm/420p05003.pdf.
[GRAPHIC] [TIFF OMITTED] TP30NO10.051

(2) Upstream (Fuel Production and Distribution)
    Upstream GHG emission reductions associated with the production and 
distribution of fuel were projected using emission factors from DOE's 
``Greenhouse Gases, Regulated Emissions, and Energy Use in 
Transportation'' (GREET1.8) model, with some modifications consistent 
with the Light-Duty Greenhouse Gas rulemaking. More information 
regarding these modifications can be found in the draft RIA Chapter 5. 
These estimates include both international and domestic emission 
reductions, since reductions in foreign exports of finished gasoline 
and/or crude would make up a significant share of the fuel savings 
resulting from the GHG standards. Thus, significant portions of the 
upstream GHG emission reductions will occur outside of the United 
States; a breakdown and discussion of projected international versus 
domestic reductions is included in the draft RIA Chapter 5. GHG 
emission reductions from upstream sources can be found in Table VI-6.

[[Page 74283]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.052

(3) HFC Emissions
    Based on projected HFC emission reductions due to the proposed AC 
leakage standards, EPA estimates the HFC reductions to be 118,885 
metric tons of CO2eq in 2018, 355,576 metric tons of 
CO2eq emissions in 2030 and 417,584 metric tons 
CO2eq in 2050, as detailed in draft RIA Chapter 5.3.4.
(4) Total (Upstream + Downstream + HFC)
    Table VI-7 combines downstream results from Table VI-5, upstream 
results Table VI-6, and HFC results to show total GHG reductions for 
calendar years 2018, 2030, and 2050.
[GRAPHIC] [TIFF OMITTED] TP30NO10.053

D. Overview of Climate Change Impacts From GHG Emissions

    Once emitted, GHGs that are the subject of this regulation can 
remain in the atmosphere for decades to centuries, meaning that (1) 
their concentrations become well-mixed throughout the global atmosphere 
regardless of emission origin, and (2) their effects on climate are 
long lasting. GHG emissions come mainly from the combustion of fossil 
fuels (coal, oil, and gas), with additional contributions from the 
clearing of forests and agricultural activities. Transportation 
activities, in aggregate, are the second largest contributor to total 
U.S. GHG emissions (27 percent) despite a decline in emissions from 
this sector during 2008.\210\
---------------------------------------------------------------------------

    \210\ U.S. EPA (2010) Inventory of U.S. Greenhouse Gas Emissions 
and Sinks: 1990-2007. EPA-430-R-10-006, Washington, DC.
---------------------------------------------------------------------------

    This section provides a summary of observed and projected changes 
in GHG emissions and associated climate change impacts. The source 
document for the section below is the Technical Support Document (TSD) 
\211\ for EPA's Endangerment and Cause or Contribute Findings Under the 
Clean Air Act (74 FR 66496, December 15, 2009). Below is the Executive 
Summary of the TSD which provides technical support for the 
endangerment and cause or contribute analyses concerning GHG emissions 
under section 202(a) of the CAA. The TSD reviews observed and projected 
changes in climate based on current and projected atmospheric GHG 
concentrations and emissions, as well as the related impacts and risks 
from climate change that are projected in the absence of GHG mitigation 
actions, including this proposal and other U.S. and global actions. The 
TSD was updated and revised based on expert technical review and public 
comment as part of EPA's rulemaking process for the final Endangerment 
Findings. The key findings synthesized here and the information 
throughout the TSD are primarily drawn from the assessment reports of 
the Intergovernmental Panel on Climate Change (IPCC), the U.S. Climate 
Change Science Program (CCSP), the U.S. Global Change Research Program 
(USGCRP), and NRC.\212\
---------------------------------------------------------------------------

    \211\ See Endangerment TSD, Note 9 above.
    \212\ For a complete list of core references from IPCC, USGCRP/
CCSP, NRC and others relied upon for development of the TSD for 
EPA's Endangerment and Cause or Contribute Findings see section 
1(b), specifically, Table 1.1 of the TSD Docket: EPA-HQ-OAR-2009-
0171-11645.
---------------------------------------------------------------------------

    In May 2010, the NRC published its comprehensive assessment, 
``Advancing the Science of Climate Change.'' \213\ It concluded that 
``climate change is occurring, is caused largely by human activities, 
and poses significant risks for--and in many cases is already 
affecting--a broad range of human and natural systems.'' Furthermore, 
the NRC stated that this conclusion is based on findings that are 
``consistent with the conclusions of recent assessments by the U.S. 
Global Change Research Program, the Intergovernmental Panel on Climate 
Change's Fourth Assessment Report, and other assessments of the state 
of scientific knowledge on climate change.'' These are the same 
assessments that served as the primary scientific references underlying 
the Administrator's Endangerment Finding. Importantly, this recent NRC 
assessment represents another independent and critical inquiry of the 
state of climate change science, separate and apart from the previous 
IPCC and USGCRP assessments. The NRC assessment is a clear affirmation 
that the scientific underpinnings of the Administrator's Endangerment 
Finding are robust, credible, and appropriately characterized by EPA.
---------------------------------------------------------------------------

    \213\ National Research Council (NRC) (2010). Advancing the 
Science of Climate Change. National Academy Press. Washington, DC.
---------------------------------------------------------------------------

(1) Observed Trends in Greenhouse Gas Emissions and Concentrations
    The primary long-lived GHGs directly emitted by human activities 
include CO2, CH4, N2O, HFCs, PFCs, and 
SF6. Greenhouse gases have a warming effect by trapping heat 
in the atmosphere that would otherwise escape to space. In 2007, U.S. 
GHG emissions were 7,150

[[Page 74284]]

teragrams \214\ of CO2 equivalent \215\ 
(TgCO2eq). The dominant gas emitted is CO2, 
mostly from fossil fuel combustion. Methane is the second largest 
component of U.S. emissions, followed by N2O and the fluorinated gases 
(HFCs, PFCs, and SF6). Electricity generation is the largest emitting 
sector (34% of total U.S. GHG emissions), followed by transportation 
(27%) and industry (19%).
---------------------------------------------------------------------------

    \214\ One teragram (Tg) = 1 million metric tons. 1 metric ton = 
1,000 kilograms = 1.102 short tons = 2,205 pounds.
    \215\ Long-lived GHGs are compared and summed together on a 
CO2-equivalent basis by multiplying each gas by its 
global warming potential (GWP), as estimated by IPCC. In accordance 
with United Nations Framework Convention on Climate Change (UNFCCC) 
reporting procedures, the U.S. quantifies GHG emissions using the 
100-year timeframe values for GWPs established in the IPCC Second 
Assessment Report.
---------------------------------------------------------------------------

    Transportation sources under section 202(a) \216\ of the CAA 
(passenger cars, light-duty trucks, other trucks and buses, 
motorcycles, and passenger cooling) emitted 1,649 TgCO2eq in 
2007, representing 23% of total U.S. GHG emissions. U.S. transportation 
sources under section 202(a) made up 4.3% of total global GHG emissions 
in 2005,\217\ which, in addition to the United States as a whole, 
ranked only behind total GHG emissions from China, Russia, and India 
but ahead of Japan, Brazil, Germany, and the rest of the world's 
countries. In 2005, total U.S. GHG emissions were responsible for 18% 
of global emissions, ranking only behind China, which was responsible 
for 19% of global GHG emissions. The scope of this proposal focuses on 
GHG emissions under section 202(a) from heavy-duty source categories 
(see Section V).
---------------------------------------------------------------------------

    \216\ Source categories under Section 202(a) of the CAA are a 
subset of source categories considered in the transportation sector 
and do not include emissions from non-highway sources such as boats, 
rail, aircraft, agricultural equipment, construction/mining 
equipment, and other off-road equipment.
    \217\ More recent emission data are available for the United 
States and other individual countries, but 2005 is the most recent 
year for which data for all countries and all gases are available.
---------------------------------------------------------------------------

    The global atmospheric CO2 concentration has increased 
about 38% from pre-industrial levels to 2009, and almost all of the 
increase is due to anthropogenic emissions. The global atmospheric 
concentration of CH4 has increased by 149% since pre-
industrial levels (through 2007); and the N2O concentration 
has increased by 23% (through 2007). The observed concentration 
increase in these gases can also be attributed primarily to 
anthropogenic emissions. The industrial fluorinated gases, HFCs, PFCs, 
and SF6, have relatively low atmospheric concentrations but 
the total radiative forcing due to these gases is increasing rapidly; 
these gases are almost entirely anthropogenic in origin.
    Historic data show that current atmospheric concentrations of the 
two most important directly emitted, long-lived GHGs (CO2 
and CH4) are well above the natural range of atmospheric 
concentrations compared to at least the last 650,000 years. Atmospheric 
GHG concentrations have been increasing because anthropogenic emissions 
have been outpacing the rate at which GHGs are removed from the 
atmosphere by natural processes over timescales of decades to 
centuries.
(2) Observed Effects Associated With Global Elevated Concentrations of 
GHGs
    Greenhouse gases, at current (and projected) atmospheric 
concentrations, remain well below published exposure thresholds for any 
direct adverse health effects and are not expected to pose exposure 
risks (i.e., breathing/inhalation).
    The global average net effect of the increase in atmospheric GHG 
concentrations, plus other human activities (e.g., land-use change and 
aerosol emissions), on the global energy balance since 1750 has been 
one of warming. This total net heating effect, referred to as forcing, 
is estimated to be +1.6 (+0.6 to +2.4) watts per square meter (W/
m2), with much of the range surrounding this estimate due to 
uncertainties about the cooling and warming effects of aerosols. 
However, as aerosol forcing has more regional variability than the 
well-mixed, long-lived GHGs, the global average might not capture some 
regional effects. The combined radiative forcing due to the cumulative 
(i.e., 1750 to 2005) increase in atmospheric concentrations of 
CO2, CH4, and N2O is estimated to be 
+2.30 (+2.07 to +2.53) W/m2. The rate of increase in 
positive radiative forcing due to these three GHGs during the 
industrial era is very likely to have been unprecedented in more than 
10,000 years.
    Warming of the climate system is unequivocal, as is now evident 
from observations of increases in global average air and ocean 
temperatures, widespread melting of snow and ice, and rising global 
average sea level. Global mean surface temperatures have risen by 1.3 
 0.32 [deg]F (0.74 [deg]C  0.18 [deg]C) over 
the last 100 years. Eight of the 10 warmest years on record have 
occurred since 2001. Global mean surface temperature was higher during 
the last few decades of the 20th century than during any comparable 
period during the preceding four centuries.
    Most of the observed increase in global average temperatures since 
the mid-20th century is very likely due to the observed increase in 
anthropogenic GHG concentrations. Climate model simulations suggest 
natural forcing alone (i.e., changes in solar irradiance) cannot 
explain the observed warming.
    U.S. temperatures also warmed during the 20th and into the 21st 
century; temperatures are now approximately 1.3 [deg]F (0.7 [deg]C) 
warmer than at the start of the 20th century, with an increased rate of 
warming over the past 30 years. Both the IPCC \218\ and the CCSP 
reports attributed recent North American warming to elevated GHG 
concentrations. In the CCSP (2008) report,\219\ the authors find that 
for North America, ``more than half of this warming [for the period 
1951-2006] is likely the result of human-caused greenhouse gas forcing 
of climate change.''
---------------------------------------------------------------------------

    \218\ Hegerl, G.C. et al. (2007) Understanding and Attributing 
Climate Change. In: Climate Change 2007: The Physical Science Basis. 
Contribution of Working Group I to the Fourth Assessment Report of 
the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, 
M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. 
Miller (eds.)]. Cambridge University Press, Cambridge, United 
Kingdom and New York, NY, USA.
    \219\ CCSP (2008) Reanalysis of Historical Climate Data for Key 
Atmospheric Features: Implications for Attribution of Causes of 
Observed Change. A Report by the U.S. Climate Change Science Program 
and the Subcommittee on Global Change Research [Randall Dole, Martin 
Hoerling, and Siegfried Schubert (eds.)]. National Oceanic and 
Atmospheric Administration, National Climatic Data Center, 
Asheville, NC, 156 pp.
---------------------------------------------------------------------------

    Observations show that changes are occurring in the amount, 
intensity, frequency and type of precipitation. Over the contiguous 
United States, total annual precipitation increased by 6.1% from 1901 
to 2008. It is likely that there have been increases in the number of 
heavy precipitation events within many land regions, even in those 
where there has been a reduction in total precipitation amount, 
consistent with a warming climate.
    There is strong evidence that global sea level gradually rose in 
the 20th century and is currently rising at an increased rate. It is 
not clear whether the increasing rate of sea level rise is a reflection 
of short-term variability or an increase in the longer-term trend. 
Nearly all of the Atlantic Ocean shows sea level rise during the last 
50 years with the rate of rise reaching a maximum (over 2 millimeters 
[mm] per year) in a band along the U.S. east coast running east-
northeast.
    Satellite data since 1979 show that annual average Arctic sea ice 
extent has shrunk by 4.1% per decade. The size and speed of recent 
Arctic summer sea ice loss is highly anomalous relative to the previous 
few thousands of years.

[[Page 74285]]

    Widespread changes in extreme temperatures have been observed in 
the last 50 years across all world regions, including the United 
States. Cold days, cold nights, and frost have become less frequent, 
while hot days, hot nights, and heat waves have become more frequent.
    Observational evidence from all continents and most oceans shows 
that many natural systems are being affected by regional climate 
changes, particularly temperature increases. However, directly 
attributing specific regional changes in climate to emissions of GHGs 
from human activities is difficult, especially for precipitation.
    Ocean CO2 uptake has lowered the average ocean pH 
(increased acidity) level by approximately 0.1 since 1750. Consequences 
for marine ecosystems can include reduced calcification by shell-
forming organisms, and in the longer term, the dissolution of carbonate 
sediments.
    Observations show that climate change is currently affecting U.S. 
physical and biological systems in significant ways. The consistency of 
these observed changes in physical and biological systems and the 
observed significant warming likely cannot be explained entirely due to 
natural variability or other confounding non-climate factors.
(3) Projections of Future Climate Change With Continued Increases in 
Elevated GHG Concentrations
    Most future scenarios that assume no explicit GHG mitigation 
actions (beyond those already enacted) project increasing global GHG 
emissions over the century, with climbing GHG concentrations. Carbon 
dioxide is expected to remain the dominant anthropogenic GHG over the 
course of the 21st century. The radiative forcing associated with the 
non-CO2 GHGs is still significant and increasing over time.
    Future warming over the course of the 21st century, even under 
scenarios of low-emission growth, is very likely to be greater than 
observed warming over the past century. According to climate model 
simulations summarized by the IPCC,\220\ through about 2030, the global 
warming rate is affected little by the choice of different future 
emissions scenarios. By the end of the 21st century, projected average 
global warming (compared to average temperature around 1990) varies 
significantly depending on the emission scenario and climate 
sensitivity assumptions, ranging from 3.2 to 7.2 [deg]F (1.8 to 4.0 
[deg]C), with an uncertainty range of 2.0 to 11.5 [deg]F (1.1 to 6.4 
[deg]C).
---------------------------------------------------------------------------

    \220\ Meehl, G.A. et al. (2007) Global Climate Projections. In: 
Climate Change 2007: The Physical Science Basis. Contribution of 
Working Group I to the Fourth Assessment Report of the 
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. 
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller 
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and 
New York, NY, USA.
---------------------------------------------------------------------------

    All of the United States is very likely to warm during this 
century, and most areas of the United States are expected to warm by 
more than the global average. The largest warming is projected to occur 
in winter over northern parts of Alaska. In western, central and 
eastern regions of North America, the projected warming has less 
seasonal variation and is not as large, especially near the coast, 
consistent with less warming over the oceans.
    It is very likely that heat waves will become more intense, more 
frequent, and longer lasting in a future warm climate, whereas cold 
episodes are projected to decrease significantly.
    Increases in the amount of precipitation are very likely in higher 
latitudes, while decreases are likely in most subtropical latitudes and 
the southwestern United States, continuing observed patterns. The mid-
continental area is expected to experience drying during summer, 
indicating a greater risk of drought.
    Intensity of precipitation events is projected to increase in the 
United States and other regions of the world. More intense 
precipitation is expected to increase the risk of flooding and result 
in greater runoff and erosion that has the potential for adverse water 
quality effects.
    It is likely that hurricanes will become more intense, with 
stronger peak winds and more heavy precipitation associated with 
ongoing increases of tropical sea surface temperatures. Frequency 
changes in hurricanes are currently too uncertain for confident 
projections.
    By the end of the century, global average sea level is projected by 
IPCC \221\ to rise between 7.1 and 23 inches (18 and 59 centimeter 
[cm]), relative to around 1990, in the absence of increased dynamic ice 
sheet loss. Recent rapid changes at the edges of the Greenland and West 
Antarctic ice sheets show acceleration of flow and thinning. While an 
understanding of these ice sheet processes is incomplete, their 
inclusion in models would likely lead to increased sea level 
projections for the end of the 21st century.
---------------------------------------------------------------------------

    \221\ IPCC (2007) Summary for Policymakers. In: Climate Change 
2007: The Physical Science Basis. Contribution of Working Group I to 
the Fourth Assessment Report of the Intergovernmental Panel on 
Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. 
Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge 
University Press, Cambridge, United Kingdom and New York, NY, USA.
---------------------------------------------------------------------------

    Sea ice extent is projected to shrink in the Arctic under all IPCC 
emissions scenarios.
(4) Projected Risks and Impacts Associated With Future Climate Change
    Risk to society, ecosystems, and many natural Earth processes 
increase with increases in both the rate and magnitude of climate 
change. Climate warming may increase the possibility of large, abrupt 
regional or global climatic events (e.g., disintegration of the 
Greenland Ice Sheet or collapse of the West Antarctic Ice Sheet). The 
partial deglaciation of Greenland (and possibly West Antarctica) could 
be triggered by a sustained temperature increase of 2 to 7 [deg]F (1 to 
4[deg] C) above 1990 levels. Such warming would cause a 13 to 20 feet 
(4 to 6 meter) rise in sea level, which would occur over a time period 
of centuries to millennia.
    The CCSP \222\ reports that climate change has the potential to 
accentuate the disparities already evident in the American health care 
system, as many of the expected health effects are likely to fall 
disproportionately on the poor, the elderly, the disabled, and the 
uninsured. The IPCC \223\ states with very high confidence that climate 
change impacts on human health in U.S. cities will be compounded by 
population growth and an aging population.
---------------------------------------------------------------------------

    \222\ Ebi, K.L., J. Balbus, P.L. Kinney, E. Lipp, D. Mills, M.S. 
O'Neill, and M. Wilson (2008) Effects of Global Change on Human 
Health. In: Analyses of the effects of global change on human health 
and welfare and human systems. A Report by the U.S. Climate Change 
Science Program and the Subcommittee on Global Change Research. 
[Gamble, J.L. (ed.), K.L. Ebi, F.G. Sussman, T.J. Wilbanks, 
(Authors)]. U.S. Environmental Protection Agency, Washington, DC, 
USA, pp. 2-1 to 2-78.
    \223\ Field, C.B. et al. (2007) North America. In: Climate 
Change 2007: Impacts, Adaptation and Vulnerability. Contribution of 
Working Group II to the Fourth Assessment Report of the 
Intergovernmental Panel on Climate Change [M.L. Parry, O.F. 
Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson 
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and 
New York, NY, USA.
---------------------------------------------------------------------------

    Severe heat waves are projected to intensify in magnitude and 
duration over the portions of the United States where these events 
already occur, with potential increases in mortality and morbidity, 
especially among the elderly, young, and frail.
    Some reduction in the risk of death related to extreme cold is 
expected. It is not clear whether reduced mortality from cold will be 
greater or less than increased heat-related mortality in the United 
States due to climate change.

[[Page 74286]]

    Increases in regional ozone pollution relative to ozone levels 
without climate change are expected due to higher temperatures and 
weaker circulation in the United States and other world cities relative 
to air quality levels without climate change. Climate change is 
expected to increase regional ozone pollution, with associated risks in 
respiratory illnesses and premature death. In addition to human health 
effects, tropospheric ozone has significant adverse effects on crop 
yields, pasture and forest growth, and species composition. The 
directional effect of climate change on ambient particulate matter 
levels remains uncertain.
    Within settlements experiencing climate change, certain parts of 
the population may be especially vulnerable; these include the poor, 
the elderly, those already in poor health, the disabled, those living 
alone, and/or indigenous populations dependent on one or a few 
resources. Thus, the potential impacts of climate change raise 
environmental justice issues.
    The CCSP \224\ concludes that, with increased CO2 and 
temperature, the life cycle of grain and oilseed crops will likely 
progress more rapidly. But, as temperature rises, these crops will 
increasingly begin to experience failure, especially if climate 
variability increases and precipitation lessens or becomes more 
variable. Furthermore, the marketable yield of many horticultural crops 
(e.g., tomatoes, onions, fruits) is very likely to be more sensitive to 
climate change than grain and oilseed crops.
---------------------------------------------------------------------------

    \224\ Backlund, P., A. Janetos, D.S. Schimel, J. Hatfield, M.G. 
Ryan, S.R. Archer, and D. Lettenmaier (2008) Executive Summary. In: 
The Effects of Climate Change on Agriculture, Land Resources, Water 
Resources, and Biodiversity in the United States. A Report by the 
U.S. Climate Change Science Program and the Subcommittee on Global 
Change Research. Washington, DC., USA, 362 pp.
---------------------------------------------------------------------------

    Higher temperatures will very likely reduce livestock production 
during the summer season in some areas, but these losses will very 
likely be partially offset by warmer temperatures during the winter 
season.
    Cold-water fisheries will likely be negatively affected; warm-water 
fisheries will generally benefit; and the results for cool-water 
fisheries will be mixed, with gains in the northern and losses in the 
southern portions of ranges.
    Climate change has very likely increased the size and number of 
forest fires, insect outbreaks, and tree mortality in the interior 
West, the Southwest, and Alaska, and will continue to do so. Over North 
America, forest growth and productivity have been observed to increase 
since the middle of the 20th century, in part due to observed climate 
change. Rising CO2 will very likely increase photosynthesis 
for forests, but the increased photosynthesis will likely only increase 
wood production in young forests on fertile soils. The combined effects 
of expected increased temperature, CO2, nitrogen deposition, 
ozone, and forest disturbance on soil processes and soil carbon storage 
remain unclear.
    Coastal communities and habitats will be increasingly stressed by 
climate change impacts interacting with development and pollution. Sea 
level is rising along much of the U.S. coast, and the rate of change 
will very likely increase in the future, exacerbating the impacts of 
progressive inundation, storm-surge flooding, and shoreline erosion. 
Storm impacts are likely to be more severe, especially along the Gulf 
and Atlantic coasts. Salt marshes, other coastal habitats, and 
dependent species are threatened by sea level rise, fixed structures 
blocking landward migration, and changes in vegetation. Population 
growth and rising value of infrastructure in coastal areas increases 
vulnerability to climate variability and future climate change.
    Climate change will likely further constrain already over-allocated 
water resources in some regions of the United States, increasing 
competition among agricultural, municipal, industrial, and ecological 
uses. Although water management practices in the United States are 
generally advanced, particularly in the West, the reliance on past 
conditions as the basis for current and future planning may no longer 
be appropriate, as climate change increasingly creates conditions well 
outside of historical observations. Rising temperatures will diminish 
snowpack and increase evaporation, affecting seasonal availability of 
water. In the Great Lakes and major river systems, lower water levels 
are likely to exacerbate challenges relating to water quality, 
navigation, recreation, hydropower generation, water transfers, and 
binational relationships. Decreased water supply and lower water levels 
are likely to exacerbate challenges relating to aquatic navigation in 
the United States.
    Higher water temperatures, increased precipitation intensity, and 
longer periods of low flows will exacerbate many forms of water 
pollution, potentially making attainment of water quality goals more 
difficult. As waters become warmer, the aquatic life they now support 
will be replaced by other species better adapted to warmer water. In 
the long term, warmer water and changing flow may result in 
deterioration of aquatic ecosystems.
    Ocean acidification is projected to continue, resulting in the 
reduced biological production of marine calcifiers, including corals.
    Climate change is likely to affect U.S. energy use and energy 
production and physical and institutional infrastructures. It will also 
likely interact with and possibly exacerbate ongoing environmental 
change and environmental pressures in settlements, particularly in 
Alaska where indigenous communities are facing major environmental and 
cultural impacts. The U.S. energy sector, which relies heavily on water 
for hydropower and cooling capacity, may be adversely impacted by 
changes to water supply and quality in reservoirs and other water 
bodies. Water infrastructure, including drinking water and wastewater 
treatment plants, and sewer and stormwater management systems, will be 
at greater risk of flooding, sea level rise and storm surge, low flows, 
and other factors that could impair performance.
    Disturbances such as wildfires and insect outbreaks are increasing 
in the United States and are likely to intensify in a warmer future 
with warmer winters, drier soils, and longer growing seasons. Although 
recent climate trends have increased vegetation growth, continuing 
increases in disturbances are likely to limit carbon storage, 
facilitate invasive species, and disrupt ecosystem services.
    Over the 21st century, changes in climate will cause species to 
shift north and to higher elevations and fundamentally rearrange U.S. 
ecosystems. Differential capacities for range shifts and constraints 
from development, habitat fragmentation, invasive species, and broken 
ecological connections will alter ecosystem structure, function, and 
services.
(5) Present and Projected U.S. Regional Climate Change Impacts
    Climate change impacts will vary in nature and magnitude across 
different regions of the United States.
    Sustained high summer temperatures, heat waves, and declining air 
quality are

[[Page 74287]]

projected in the Northeast,\225\ Southeast,\226\ Southwest,\227\ and 
Midwest.\228\ Projected climate change would continue to cause loss of 
sea ice, glacier retreat, permafrost thawing, and coastal erosion in 
Alaska.
---------------------------------------------------------------------------

    \225\ Northeast includes West Virginia, Maryland, Delaware, 
Pennsylvania, New Jersey, New York, Connecticut, Rhode Island, 
Massachusetts, Vermont, New Hampshire, and Maine.
    \226\ Southeast includes Kentucky, Virginia, Arkansas, 
Tennessee, North Carolina, South Carolina, southeast Texas, 
Louisiana, Mississippi, Alabama, Georgia, and Florida.
    \227\ Southwest includes California, Nevada, Utah, western 
Colorado, Arizona, New Mexico (except the extreme eastern section), 
and southwest Texas.
    \228\ The Midwest includes Minnesota, Wisconsin, Michigan, Iowa, 
Illinois, Indiana, Ohio, and Missouri.
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    Reduced snowpack, earlier spring snowmelt, and increased likelihood 
of seasonal summer droughts are projected in the Northeast, 
Northwest,\229\ and Alaska. More severe, sustained droughts and water 
scarcity are projected in the Southeast, Great Plains,\230\ and 
Southwest.
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    \229\ The Northwest includes Washington, Idaho, western Montana, 
and Oregon.
    \230\ The Great Plains includes central and eastern Montana, 
North Dakota, South Dakota, Wyoming, Nebraska, eastern Colorado, 
Nebraska, Kansas, extreme eastern New Mexico, central Texas, and 
Oklahoma
---------------------------------------------------------------------------

    The Southeast, Midwest, and Northwest in particular are expected to 
be impacted by an increased frequency of heavy downpours and greater 
flood risk.
    Ecosystems of the Southeast, Midwest, Great Plains, Southwest, 
Northwest, and Alaska are expected to experience altered distribution 
of native species (including local extinctions), more frequent and 
intense wildfires, and an increase in insect pest outbreaks and 
invasive species.
    Sea level rise is expected to increase storm surge height and 
strength, flooding, erosion, and wetland loss along the coasts, 
particularly in the Northeast, Southeast, and islands.
    Warmer water temperatures and ocean acidification are expected to 
degrade important aquatic resources of islands and coasts such as coral 
reefs and fisheries.
    A longer growing season, low levels of warming, and fertilization 
effects of carbon dioxide may benefit certain crop species and forests, 
particularly in the Northeast and Alaska. Projected summer rainfall 
increases in the Pacific islands may augment limited freshwater 
supplies. Cold-related mortality is projected to decrease, especially 
in the Southeast. In the Midwest in particular, heating oil demand and 
snow-related traffic accidents are expected to decrease.
    Climate change impacts in certain regions of the world may 
exacerbate problems that raise humanitarian, trade, and national 
security issues for the United States. The IPCC \231\ identifies the 
most vulnerable world regions as the Arctic, because of the effects of 
high rates of projected warming on natural systems; Africa, especially 
the sub-Saharan region, because of current low adaptive capacity as 
well as climate change; small islands, due to high exposure of 
population and infrastructure to risk of sea level rise and increased 
storm surge; and Asian mega-deltas, such as the Ganges-Brahmaputra and 
the Zhujiang, due to large populations and high exposure to sea level 
rise, storm surge and river flooding. Climate change has been described 
as a potential threat multiplier with regard to national security 
issues.
---------------------------------------------------------------------------

    \231\ Parry, M.L. et al. (2007) Technical Summary. In: Climate 
Change 2007: Impacts, Adaptation and Vulnerability. Contribution of 
Working Group II to the Fourth Assessment Report of the 
Intergovernmental Panel on Climate Change [M.L. Parry, O.F. 
Canziani, J.P. Palutikof, P.J. van der Linden, and C.E. Hanson 
(eds.)], Cambridge University Press, Cambridge, United Kingdom, pp. 
23S78.
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E. Changes in Atmospheric CO2 Concentrations, Global Mean 
Temperature, Sea Level Rise, and Ocean pH Associated with the 
Proposal's GHG Emissions Reductions

    EPA examined \232\ the reductions in CO2 and other GHGs 
associated with this proposal and analyzed the projected effects on 
atmospheric CO2 concentrations, global mean surface 
temperature, sea level rise, and ocean pH which are common variables 
used as indicators of climate change. The analysis projects that the 
preferred alternative of this proposal will reduce atmospheric 
concentrations of CO2, global climate warming and sea level 
rise. Although the projected reductions and improvements are small in 
overall magnitude by themselves, they are quantifiable and would 
contribute to reducing the risks associated with climate change.
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    \232\ Using the Model for the Assessment of Greenhouse Gas 
Induced Climate Change (MAGICC) 5.3v2, http://www.cgd.ucar.edu/cas/wigley/magicc/), EPA estimated the effects of this proposal's 
greenhouse gas emissions reductions on global mean temperature and 
sea level. Please refer to Chapter 8.4 of the RIA for additional 
information.
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    EPA determines that the projected reductions in atmospheric 
CO2, global mean temperature and sea level rise are 
meaningful in the context of this proposal. In addition, EPA has 
conducted an analysis to evaluate the projected changes in ocean pH in 
the context of the changes in emissions from this proposal. The results 
for projected atmospheric CO2 concentrations are estimated 
to be reduced by 0.693 to 0.784 part per million by volume (ppmv) 
(average of 0.732 ppmv), global mean temperature is estimated to be 
reduced by 0.002 to 0.004[deg]C, sea-level rise is projected to be 
reduced by approximately 0.012-0.048 cm based on a range of climate 
sensitivities, and ocean pH will increase by 0.0003 pH units by 2100.
(1) Estimated Projected Reductions in Atmospheric CO2 
Concentration, Global Mean Surface Temperatures, Sea Level Rise, and 
Ocean pH
    EPA estimated changes in the atmospheric CO2 
concentration, global mean temperature, and sea level rise out to 2100 
resulting from the emissions reductions in this proposal using the GCAM 
(Global Change Assessment Model, formerly MiniCAM), integrated 
assessment model \233\ coupled with the Model for the Assessment of 
Greenhouse Gas Induced Climate Change (MAGICC, version 5.3v2).\234\ 
GCAM was used to create the globally and temporally consistent set of 
climate relevant variables required for running MAGICC. MAGICC was then 
used to estimate the projected change in these variables over time. 
Given the magnitude of the estimated emissions reductions associated 
with the rule, a simple climate model such as MAGICC is reasonable for 
estimating the atmospheric and climate response. This widely-used, peer 
reviewed modeling tool was also used to project temperature and sea 
level rise under different emissions scenarios in the Third and Fourth 
Assessments of the IPCC.
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    \233\ GCAM is a long-term, global integrated assessment model of 
energy, economy, agriculture and land use, that considers the 
sources of emissions of a suite of GHG's, emitted in 14 globally 
disaggregated regions, the fate of emissions to the atmosphere, and 
the consequences of changing concentrations of greenhouse related 
gases for climate change. GCAM begins with a representation of 
demographic and economic developments in each region and combines 
these with assumptions about technology development to describe an 
internally consistent representation of energy, agriculture, land-
use, and economic developments that in turn shape global emissions.
    Brenkert A, S. Smith, S. Kim, and H. Pitcher, 2003: Model 
Documentation for the MiniCAM. PNNL-14337, Pacific Northwest 
National Laboratory, Richland, Washington.
    \234\ Wigley, T.M.L. 2008. MAGICC 5.3.v2 User Manual. UCAR--
Climate and Global Dynamics Division, Boulder, Colorado. http://www.cgd.ucar.edu/cas/wigley/magicc/.
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    The integrated impact of the following pollutant and greenhouse gas 
emissions changes are considered: CO2, CH4, 
N2O, NOX, CO2 and SO2, and 
volatile organic compounds (VOC). For CO, SO2, and 
NOX, emissions reductions were estimated for 2018, 2030, and 
2050 (provided in Section VII.A). For CO2, CH4, 
and N2O an annual time-series of

[[Page 74288]]

(upstream + downstream) emissions reductions estimated from the 
proposal were input directly. The GHG emissions reductions, from 
Section VI.C, were applied as net reductions to a global reference case 
(or baseline) emissions scenario in GCAM to generate an emissions 
scenario specific to this proposal. EPA linearly scaled emissions 
reductions between a zero input value in 2013 and the value supplied 
for 2018 to produce the reductions for 2014-2018. A similar scaling was 
used for 2019-2029 and 2031-2050. The emissions reductions past 2050 
were scaled with total U.S. road transportation fuel consumption from 
the GCAM reference scenario. Road transport fuel consumption past 2050 
does not change significantly and thus emissions reductions remain 
relatively constant from 2050 through 2100. Specific details about the 
reference case scenario and how the emissions reductions were applied 
to generate the scenario can be found in the proposal's RIA, Chapter 
8.4.
    MAGICC is a global model and is primarily concerned with climate, 
therefore the impact of short-lived climate forcing agents (e.g., 
O3) are not explicitly simulated as in regional air quality 
models. While many precursors related to short-lived climate forcers 
such as ozone are considered, MAGICC simulates the longer term effect 
on climate from long-lived GHGs. The impacts to ground-level ozone and 
other non-GHGs are discussed in Section VII of this proposal and the 
draft RIA Chapter 8.2. Some aerosols, such as black carbon, cause a 
positive forcing or warming effect by absorbing incoming solar 
radiation. There remain some significant scientific uncertainties about 
black carbon's total climate effect,\235\ as well as concerns about how 
to treat the short-lived black carbon emissions alongside the long-
lived, well-mixed greenhouse gases in a common framework (e.g., what 
are the appropriate metrics to compare the warming and/or climate 
effects of the different substances, given that, unlike greenhouse 
gases, the magnitude of aerosol effects can vary immensely with 
location and season of emissions). Further, estimates of the direct 
radiative forcing of individual species are less certain than the total 
direct aerosol radiative forcing.
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    \235\ The range of uncertainty in the current magnitude of black 
carbon's climate forcing effect is evidenced by the ranges presented 
by the IPCC Fourth Assessment Report (2007) and the more recent 
study by Ramanathan, V. and Carmichael, G. (2008) Global and 
regional climate changes due to black carbon. Nature Geoscience, 
1(4): 221-227.
---------------------------------------------------------------------------

    There is no single accepted methodology for transforming black 
carbon emissions into temperature change or CO2eq emissions. 
The interaction of black carbon (and other co-emitted aerosol species) 
with clouds is especially poorly quantified, and this factor is key to 
any attempt to estimate the net climate impacts of black carbon. While 
black carbon is likely to be an important contributor to climate 
change, it would be premature to include quantification of black carbon 
climate impacts in an analysis of the proposed standards at this time.
    Changes in atmospheric CO2 concentration, global mean 
temperature, and sea level rise for both the reference case and the 
emissions scenarios associated with this proposal were computed using 
MAGICC. To calculate the reductions in the atmospheric CO2 
concentrations as well as in temperature and sea level resulting from 
this proposal, the output from the policy scenario associated with the 
preferred approach of this proposal was subtracted from an existing 
Global Change Assessment Model (GCAM, formerly MiniCAM) reference 
emission scenario. To capture some key uncertainties in the climate 
system with the MAGICC model, changes in atmospheric CO2, 
global mean temperature and sea level rise were projected across the 
most current IPCC range of climate sensitivities which ranges from 1.5 
[deg]C to 6.0 [deg]C.\236\ This range reflects the uncertainty for 
equilibrium climate sensitivity for how much global mean temperature 
would rise if the concentration of carbon dioxide in the atmosphere 
were to double. The information for this range come from constraints 
from past climate change on various time scales, and the spread of 
results for climate sensitivity from ensembles of models.\237\ Details 
about this modeling analysis can be found in the draft RIA Chapter 8.4.
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    \236\ In IPCC reports, equilibrium climate sensitivity refers to 
the equilibrium change in the annual mean global surface temperature 
following a doubling of the atmospheric equivalent carbon dioxide 
concentration. The IPCC states that climate sensitivity is 
``likely'' to be in the range of 2 [deg]C to 4.5 [deg]C, ``very 
unlikely'' to be less than 1.5 [deg]C, and ``values substantially 
higher than 4.5[deg] C cannot be excluded.'' IPCC WGI, 2007, Climate 
Change 2007--The Physical Science Basis, Contribution of Working 
Group I to the Fourth Assessment Report of the IPCC, http://www.ipcc.ch/.
    \237\ Meehl, G.A. et al. (2007) Global Climate Projections. In: 
Climate Change 2007: The Physical Science Basis. Contribution of 
Working Group I to the Fourth Assessment Report of the 
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. 
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller 
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and 
New York, NY, USA.
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    The results of this modeling, summarized in Table VI-8, show small 
but quantifiable reductions in atmospheric CO2 
concentrations, projected global mean temperature and sea level 
resulting from this proposal, across all climate sensitivities. As a 
result of the emission reductions from the proposed standards for this 
proposal, the atmospheric CO2 concentration is projected to 
be reduced by an average of 0.732 ppmv, the global mean temperature is 
projected to be reduced by approximately 0.002-0.004 [deg]C by 2100, 
and global mean sea level rise is projected to be reduced by 
approximately 0.012-0.050 cm by 2100. The range of reductions in global 
mean temperature and sea level rise is larger because CO2 
concentrations are not tightly coupled to climate sensitivity, whereas 
the magnitude of temperature change response to CO2 changes 
(and therefore sea level rise) is tightly coupled to climate 
sensitivity in the MAGICC model.

[[Page 74289]]

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    The reductions are small relative to the IPCC's 2100 ``best 
estimates'' \238\ for global mean temperature increases (1.1--6.4 
[ordm]C) and sea level rise (0.18-0.59m) for all global GHG emissions 
sources for a range of emissions scenarios.\239\ These ``best 
estimates'' are assessed from a hierarchy of models that encompass a 
simple climate model, several Earth Models of Intermediate Complexity, 
and a large number of Atmosphere-Ocean Global Circulation Models and 
are based on the six major scenarios described in the Special Report on 
Emissions Scenarios, not including dynamical ice sheet behavior that 
would lead to an increase in sea level rise. Further discussion of 
EPA's modeling analysis is found in the draft RIA, Chapter 8.
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    \238\ IPCC's ``best estimates'' at the end of the 21st century 
from Table TS.6 in the Technical Summary: Contribution of Working 
Group I (Solomon et al., 2007).
    \239\ IPCC (2007) Climate Change 2007: The Physical Science 
Basis. Contribution of Working Group I to the Fourth Assessment 
Report of the Intergovernmental Panel on Climate Change [Solomon, 
S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, 
and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, 
United Kingdom and New York, NY, USA.
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    EPA used the Program CO2SYS,\240\ version 1.05 to estimate 
projected changes in ocean pH for tropical waters based on the 
atmospheric CO2 concentration change (reduction) resulting 
from this proposal. The program performs calculations relating 
parameters of the CO2 system in seawater. EPA used the 
program to calculate ocean pH as a function of atmospheric 
CO2 concentrations, among other specified input conditions. 
Based on the projected atmospheric CO2 concentration 
reductions (0.731 ppmv by 2100 for a climate sensitivity of 3.0) that 
would result from this proposal, the program calculates an increase in 
ocean pH of 0.0003 pH units. Thus, this analysis indicates the 
projected decrease in atmospheric CO2 concentrations from 
the preferred approach associated with this proposal would result in an 
increase in ocean pH. For additional validation, results were generated 
from the atmospheric CO2 concentration change for each 
climate sensitivity case (1.5 to 6.0) and using different known 
constants from the literature. A comprehensive discussion of the 
modeling analysis associated with ocean pH is provided in the draft 
RIA, Chapter 8.
---------------------------------------------------------------------------

    \240\ Lewis, E., and D. W. R. Wallace. 1998. Program Developed 
for CO2 System Calculations. ORNL/CDIAC-105. Carbon 
Dioxide Information Analysis Center, Oak Ridge National Laboratory, 
U.S. Department of Energy, Oak Ridge, Tennessee.
---------------------------------------------------------------------------

(2) Proposal's Effect on Climate
    As a substantial portion of CO2 emitted into the 
atmosphere is not removed by natural processes for millennia, each unit 
of CO2 not emitted into the atmosphere avoids essentially 
permanent climate change on centennial time scales. Reductions in 
emissions in the near-term are important in determining long-term 
climate stabilization and associated impacts experienced not just over 
the next decades but in the coming centuries and millennia.\241\ Though 
the magnitude of the avoided climate change projected here is small, 
these reductions would represent a reduction in the adverse risks 
associated with climate change (though these risks were not formally 
estimated for this proposal) across a range of equilibrium climate 
sensitivities.
---------------------------------------------------------------------------

    \241\ National Research Council (NRC) (2010). Climate 
Stabilization Targets. Committee on Stabilization Targets for 
Atmospheric Greenhouse Gas Concentrations; Board on Atmospheric 
Sciences and Climate, Division of Earth and Life Sciences, National 
Academy Press. Washington, DC.
---------------------------------------------------------------------------

    EPA's analysis of the proposal's impact on global climate 
conditions is intended to quantify these potential reductions using the 
best available science. While EPA's modeling results of the effect of 
this proposal alone show small differences in climate effects 
(CO2 concentration, temperature, sea-level rise, ocean pH), 
when expressed in terms of global climate endpoints and global GHG 
emissions, yield results that are repeatable and consistent within the 
modeling frameworks used.

VII. How Would This Proposal Impact Non-GHG Emissions and Their 
Associated Effects?

A. Emissions Inventory Impacts

(1) Upstream Impacts of the Program
    Increasing efficiency in heavy-duty vehicles would result in 
reduced fuel demand and therefore reductions in the emissions 
associated with all processes involved in getting petroleum to the 
pump. These projected upstream emission impacts on criteria pollutants 
are summarized in Table VII-1. Table VII-2 shows the corresponding 
projected impacts on upstream air toxic emissions in 2030.

[[Page 74290]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.055

    To project these impacts, EPA estimated the impact of reduced 
petroleum volumes on the extraction and transportation of crude oil as 
well as the production and distribution of finished gasoline and 
diesel. For the purpose of assessing domestic-only emission reductions 
it was necessary to estimate the fraction of fuel savings attributable 
to domestic finished gasoline and diesel, and of this fuel what 
fraction is produced from domestic crude. For this analysis EPA 
estimated that 50 percent of fuel savings is attributable to domestic 
finished gasoline and diesel and that 90 percent of this gasoline and 
diesel originated from imported crude. Emission factors for most 
upstream emission sources are based on the GREET1.8 model, developed by 
DOE's Argonne National Laboratory but in some cases the GREET values 
were modified or updated by EPA to be consistent with the National 
Emission Inventory. These updates are consistent with those used for 
the upstream analysis included in the Light-Duty GHG rulemaking. More 
information on the development of the emission factors used in this 
analysis can be found in draft RIA Chapter 5.
(2) Downstream Impacts of the Program
    While these proposed rules do not regulate non-GHG pollutants, EPA 
expects reductions in downstream emissions of most non-GHG pollutants. 
These pollutants include NOX, SO2, CO, and HC. 
The primary reason for this is the improvements in road load 
(aerodynamics and tire rolling resistance) under the proposal. Another 
reason is that emissions from certain pollutants (e.g., SO2) 
are proportional to fuel consumption. For vehicle types not affected by 
road load improvements, non-GHG emissions may increase very slightly 
due to VMT rebound. EPA also anticipates the use of APUs in combination 
tractors for GHG reduction purposes during extended idling. These units 
exhibit different non-GHG emissions characteristics compared to the on-
road engines they would replace during extended idling. EPA used MOVES 
to determine non-GHG emissions inventories for baseline and control 
cases. Further information about the MOVES analysis is available in 
Section VI and RIA Chapter 5. The improvements in road load, use of 
APUs, and VMT rebound were included in the MOVES runs and post-
processing. Table VII-3 summarizes the downstream criteria pollutant 
impacts of this proposal. Most of the impacts shown are through 
projected increased APU use. Because APUs are required to meet much 
less stringent PM2.5 standards than on-road engines, the 
projected widespread use of APUs leads to higher PM2.5. 
Table VII-4 summarizes the downstream air toxics impacts of this 
proposal.

[[Page 74291]]

[GRAPHIC] [TIFF OMITTED] TP30NO10.056

(3) Total Impacts of the Program
    As shown in Table VII-5 and Table VII-6, the agencies estimate that 
this program would result in reductions of NOX, VOC, CO, 
SOX, and air toxics. For NOX, VOC, and CO, much 
of the net reductions are realized through the use of APUs, which emit 
these pollutants at a lower rate than on-road engines during extended 
idle operation. Additional reductions are achieved in all pollutants 
through reduced road load (improved aerodynamics and tire rolling 
resistance), which reduces the amount of work required to travel a 
given distance. For SOX, downstream emissions are roughly 
proportional to fuel consumption; therefore a decrease is seen in both 
upstream and downstream sources. The downstream increase in 
PM2.5 due to APU use is mostly negated by upstream 
PM2.5 reductions, though our calculations show a slight net 
increase in 2030 and 2050.\242\
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    \242\ Although the net impact is small when aggregated to the 
national level, it is unlikely that the geographic location of 
increases in downstream PM2.5 emissions will coincide 
with the location of decreases in upstream PM2.5 
emissions. Impacts of the emissions changes will be included in the 
air quality modeling that will be completed for the final 
rulemaking.
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[[Page 74292]]



B. Health Effects of Non-GHG Pollutants

    In this section we discuss health effects associated with exposure 
to some of the criteria and air toxic pollutants impacted by the 
proposed heavy-duty vehicle standards.
(1) Particulate Matter
(a) Background
    Particulate matter is a generic term for a broad class of 
chemically and physically diverse substances. It can be principally 
characterized as discrete particles that exist in the condensed (liquid 
or solid) phase spanning several orders of magnitude in size. Since 
1987, EPA has delineated that subset of inhalable particles small 
enough to penetrate to the thoracic region (including the 
tracheobronchial and alveolar regions) of the respiratory tract 
(referred to as thoracic particles). Current National Ambient Air 
Quality Standards (NAAQS) use PM2.5 as the indicator for 
fine particles (with PM2.5 referring to particles with a 
nominal mean aerodynamic diameter less than or equal to 2.5 [mu]m), and 
use PM10 as the indicator for purposes of regulating the 
coarse fraction of PM10 (referred to as thoracic coarse 
particles or coarse-fraction particles; generally including particles 
with a nominal mean aerodynamic diameter greater than 2.5 [mu]m and 
less than or equal to 10 [mu]m, or PM10-2.5). Ultrafine 
particles are a subset of fine particles, generally less than 100 
nanometers (0.1 [mu]m) in aerodynamic diameter.
    Fine particles are produced primarily by combustion processes and 
by transformations of gaseous emissions (e.g., SOX, 
NOX, and VOC) in the atmosphere. The chemical and physical 
properties of PM2.5 may vary greatly with time, region, 
meteorology, and source category. Thus, PM2.5 may include a 
complex mixture of different pollutants including sulfates, nitrates, 
organic compounds, elemental carbon and metal compounds. These 
particles can remain in the atmosphere for days to weeks and travel 
hundreds to thousands of kilometers.
(b) Health Effects of PM
    Scientific studies show ambient PM is associated with a series of 
adverse health effects. These health effects are discussed in detail in 
EPA's Integrated Science Assessment for Particulate Matter (ISA).\243\ 
Further discussion of health effects associated with PM can also be 
found in the draft RIA for this proposal. The ISA summarizes evidence 
associated with PM2.5, PM10-2.5, and ultrafine 
particles.
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    \243\ U.S. EPA (2009) Integrated Science Assessment for 
Particulate Matter (Final Report). U.S. Environmental Protection 
Agency, Washington, DC, EPA/600/R-08/139F, Docket EPA-HQ-OAR-2010-
0162.
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    The ISA concludes that health effects associated with short-term 
exposures (hours to days) to ambient PM2.5 include 
mortality, cardiovascular effects, such as altered vasomotor function 
and hospital admissions and emergency department visits for ischemic 
heart disease and congestive heart failure, and respiratory effects, 
such as exacerbation of asthma symptoms in children and hospital 
admissions and emergency department visits for chronic obstructive 
pulmonary disease and respiratory infections.\244\ The ISA notes that 
long-term exposure to PM2.5 (months to years) is associated 
with the development/progression of cardiovascular disease, premature 
mortality, and respiratory effects, including reduced lung function 
growth, increased respiratory symptoms, and asthma development.\245\ 
The ISA concludes that the currently available scientific evidence from 
epidemiologic, controlled human exposure, and toxicological studies 
supports a causal association between short- and long-term exposures to 
PM2.5 and cardiovascular effects and mortality. Furthermore, 
the ISA concludes that the collective evidence supports likely causal 
associations between short- and long-term PM2.5 exposures and 
respiratory effects. The ISA also concludes that the scientific 
evidence is suggestive of a causal association for reproductive and 
developmental effects and cancer, mutagenicity, and genotoxicity and 
long-term exposure to PM2.5.\246\
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    \244\ See U.S. EPA, 2009 Final PM ISA, Note 243, at Section 
2.3.1.1.
    \245\ See U.S. EPA 2009 Final PM ISA, Note 243, at page 2-12, 
Sections 7.3.1.1 and 7.3.2.1.
    \246\ See U.S. EPA 2009 Final PM ISA, Note 243, at Section 
2.3.2.
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    For PM10-2.5, the ISA concludes that the current 
evidence is suggestive of a causal relationship between short-term 
exposures and cardiovascular effects, such as hospitalization for 
ischemic heart disease. There is also suggestive evidence of a causal 
relationship between short-term PM10-2.5 exposure and 
mortality and respiratory effects. Data are inadequate to draw 
conclusions regarding the health effects associated with long-term 
exposure to PM10-2.5.\247\
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    \247\ See U.S. EPA 2009 Final PM ISA, Note 243, at Section 
2.3.4, Table 2-6.
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    For ultrafine particles, the ISA concludes that there is suggestive 
evidence of a causal relationship between short-term exposures and 
cardiovascular effects, such as changes in heart rhythm and blood 
vessel function. It also concludes that there is suggestive evidence of 
association between short-term exposure to ultrafine particles and 
respiratory effects. Data are inadequate to draw conclusions regarding 
the health effects associated with long-term exposure to ultrafine 
particles.\248\
---------------------------------------------------------------------------

    \248\ See U.S. EPA 2009 Final PM ISA, Note 243, at Section 
2.3.5, Table 2-6.
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(2) Ozone
(a) Background
    Ground-level ozone pollution is typically formed by the reaction of 
VOC and NOX in the lower atmosphere in the presence of 
sunlight. These pollutants, often referred to as ozone precursors, are 
emitted by many types of pollution sources, such as highway and nonroad 
motor vehicles and engines, power plants, chemical plants, refineries, 
makers of consumer and commercial products, industrial facilities, and 
smaller area sources.
    The science of ozone formation, transport, and accumulation is 
complex. Ground-level ozone is produced and destroyed in a cyclical set 
of chemical reactions, many of which are sensitive to temperature and 
sunlight. When ambient temperatures and sunlight levels remain high for 
several days and the air is relatively stagnant, ozone and its 
precursors can build up and result in more ozone than typically occurs 
on a single high-temperature day. Ozone can be transported hundreds of 
miles downwind from precursor emissions, resulting in elevated ozone 
levels even in areas with low local VOC or NOX emissions.
(b) Health Effects of Ozone
    The health and welfare effects of ozone are well documented and are 
assessed in EPA's 2006 Air Quality Criteria Document and 2007 Staff 
Paper.249 250 People who are more susceptible to effects 
associated with exposure to ozone can include children, the elderly, 
and individuals with respiratory disease such as asthma. Those with 
greater exposures to ozone, for instance due to time spent outdoors 
(e.g., children and outdoor workers), are of particular concern. Ozone 
can irritate the respiratory system, causing coughing, throat 
irritation, and breathing discomfort. Ozone can reduce

[[Page 74293]]

lung function and cause pulmonary inflammation in healthy individuals. 
Ozone can also aggravate asthma, leading to more asthma attacks that 
require medical attention and/or the use of additional medication. 
Thus, ambient ozone may cause both healthy and asthmatic individuals to 
limit their outdoor activities. In addition, there is suggestive 
evidence of a contribution of ozone to cardiovascular-related morbidity 
and highly suggestive evidence that short-term ozone exposure directly 
or indirectly contributes to non-accidental and cardiopulmonary-related 
mortality, but additional research is needed to clarify the underlying 
mechanisms causing these effects. In a recent report on the estimation 
of ozone-related premature mortality published by NRC, a panel of 
experts and reviewers concluded that short-term exposure to ambient 
ozone is likely to contribute to premature deaths and that ozone-
related mortality should be included in estimates of the health 
benefits of reducing ozone exposure.\251\ Animal toxicological evidence 
indicates that with repeated exposure, ozone can inflame and damage the 
lining of the lungs, which may lead to permanent changes in lung tissue 
and irreversible reductions in lung function. The respiratory effects 
observed in controlled human exposure studies and animal studies are 
coherent with the evidence from epidemiologic studies supporting a 
causal relationship between acute ambient ozone exposures and increased 
respiratory-related emergency room visits and hospitalizations in the 
warm season. In addition, there is suggestive evidence of a 
contribution of ozone to cardiovascular-related morbidity and non-
accidental and cardiopulmonary mortality.
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    \249\ U.S. EPA. (2006). Air Quality Criteria for Ozone and 
Related Photochemical Oxidants (Final). EPA/600/R-05/004aF-cF. 
Washington, DC: U.S. EPA. Docket EPA-HQ-OAR-2010-0162.
    \250\ U.S. EPA. (2007). Review of the National Ambient Air 
Quality Standards for Ozone: Policy Assessment of Scientific and 
Technical Information, OAQPS Staff Paper. EPA-452/R-07-003. 
Washington, DC, U.S. EPA. Docket EPA-HQ-OAR-2010-0162.
    \251\ National Research Council (NRC), 2008. Estimating 
Mortality Risk Reduction and Economic Benefits from Controlling 
Ozone Air Pollution. The National Academies Press: Washington, DC 
Docket EPA-HQ-OAR-2010-0162
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(3) Nitrogen Oxides and Sulfur Oxides
(a) Background
    Nitrogen dioxide (NO2) is a member of the NOX 
family of gases. Most NO2 is formed in the air through the 
oxidation of nitric oxide (NO) emitted when fuel is burned at a high 
temperature. SO2, a member of the sulfur oxide 
(SOX) family of gases, is formed from burning fuels 
containing sulfur (e.g., coal or oil derived), extracting gasoline from 
oil, or extracting metals from ore.
    SO2 and NO2 can dissolve in water droplets 
and further oxidize to form sulfuric and nitric acid which react with 
ammonia to form sulfates and nitrates, both of which are important 
components of ambient PM. The health effects of ambient PM are 
discussed in Section VII. B. (1) (b) of this preamble. NOX 
and NMHC are the two major precursors of ozone. The health effects of 
ozone are covered in Section VII. B. (2)(b).
(b) Health Effects of NO2
    Information on the health effects of NO2 can be found in 
the EPA Integrated Science Assessment (ISA) for Nitrogen Oxides.\252\ 
The EPA has concluded that the findings of epidemiologic, controlled 
human exposure, and animal toxicological studies provide evidence that 
is sufficient to infer a likely causal relationship between respiratory 
effects and short-term NO2 exposure. The ISA concludes that 
the strongest evidence for such a relationship comes from epidemiologic 
studies of respiratory effects including symptoms, emergency department 
visits, and hospital admissions. The ISA also draws two broad 
conclusions regarding airway responsiveness following NO2 
exposure. First, the ISA concludes that NO2 exposure may 
enhance the sensitivity to allergen-induced decrements in lung function 
and increase the allergen-induced airway inflammatory response 
following 30-minute exposures of asthmatics to NO2 
concentrations as low as 0.26 ppm. In addition, small but significant 
increases in non-specific airway hyperresponsiveness were reported 
following 1-hour exposures of asthmatics to 0.1 ppm NO2. 
Second, exposure to NO2 has been found to enhance the 
inherent responsiveness of the airway to subsequent nonspecific 
challenges in controlled human exposure studies of asthmatic subjects. 
Enhanced airway responsiveness could have important clinical 
implications for asthmatics since transient increases in airway 
responsiveness following NO2 exposure have the potential to 
increase symptoms and worsen asthma control. Together, the 
epidemiologic and experimental data sets form a plausible, consistent, 
and coherent description of a relationship between NO2 
exposures and an array of adverse health effects that range from the 
onset of respiratory symptoms to hospital admission.
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    \252\ U.S. EPA (2008). Integrated Science Assessment for Oxides 
of Nitrogen--Health Criteria (Final Report). EPA/600/R-08/071. 
Washington, DC: U.S.EPA. Docket EPA-HQ-OAR-2010-0162 .
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    Although the weight of evidence supporting a causal relationship is 
somewhat less certain than that associated with respiratory morbidity, 
NO2 has also been linked to other health endpoints. These 
include all-cause (nonaccidental) mortality, hospital admissions or 
emergency department visits for cardiovascular disease, and decrements 
in lung function growth associated with chronic exposure.
(c) Health Effects of SO2
    Information on the health effects of SO2 can be found in 
the EPA Integrated Science Assessment for Sulfur Oxides.\253\ 
SO2 has long been known to cause adverse respiratory health 
effects, particularly among individuals with asthma. Other potentially 
sensitive groups include children and the elderly. During periods of 
elevated ventilation, asthmatics may experience symptomatic 
bronchoconstriction within minutes of exposure. Following an extensive 
evaluation of health evidence from epidemiologic and laboratory 
studies, the EPA has concluded that there is a causal relationship 
between respiratory health effects and short-term exposure to 
SO2. Separately, based on an evaluation of the epidemiologic 
evidence of associations between short-term exposure to SO2 
and mortality, the EPA has concluded that the overall evidence is 
suggestive of a causal relationship between short-term exposure to 
SO2 and mortality.
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    \253\ U.S. EPA. (2008). Integrated Science Assessment (ISA) for 
Sulfur Oxides--Health Criteria (Final Report). EPA/600/R-08/047F. 
Washington, DC: U.S. Environmental Protection Agency. Docket EPA-HQ-
OAR-2010-0162.
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(4) Carbon Monoxide
    Information on the health effects of CO can be found in the EPA 
Integrated Science Assessment (ISA) for Carbon Monoxide.\254\ The ISA 
concludes that ambient concentrations of CO are associated with a 
number of adverse health effects.\255\ This section provides a summary 
of the health effects associated with exposure to ambient 
concentrations of CO.\256\
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    \254\ U.S. EPA, 2010. Integrated Science Assessment for Carbon 
Monoxide (Final Report). U.S. Environmental Protection Agency, 
Washington, DC, EPA/600/R-09/019F, 2010. Available at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686. Docket EPA-HQ-
OAR-2010-0162.
    \255\ The ISA evaluates the health evidence associated with 
different health effects, assigning one of five ``weight of 
evidence'' determinations: causal relationship, likely to be a 
causal relationship, suggestive of a causal relationship, inadequate 
to infer a causal relationship, and not likely to be a causal 
relationship. For definitions of these levels of evidence, please 
refer to Section 1.6 of the ISA.
    \256\ Personal exposure includes contributions from many 
sources, and in many different environments. Total personal exposure 
to CO includes both ambient and nonambient components; and both 
components may contribute to adverse health effects.

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[[Page 74294]]

    Human clinical studies of subjects with coronary artery disease 
show a decrease in the time to onset of exercise-induced angina (chest 
pain) and electrocardiogram changes following CO exposure. In addition, 
epidemiologic studies show associations between short-term CO exposure 
and cardiovascular morbidity, particularly increased emergency room 
visits and hospital admissions for coronary heart disease (including 
ischemic heart disease, myocardial infarction, and angina). Some 
epidemiologic evidence is also available for increased hospital 
admissions and emergency room visits for congestive heart failure and 
cardiovascular disease as a whole. The ISA concludes that a causal 
relationship is likely to exist between short-term exposures to CO and 
cardiovascular morbidity. It also concludes that available data are 
inadequate to conclude that a causal relationship exists between long-
term exposures to CO and cardiovascular morbidity.
    Animal studies show various neurological effects with in-utero CO 
exposure. Controlled human exposure studies report inconsistent neural 
and behavioral effects following low-level CO exposures. The ISA 
concludes the evidence is suggestive of a causal relationship with both 
short- and long-term exposure to CO and central nervous system effects.
    A number of epidemiologic and animal toxicological studies cited in 
the ISA have evaluated associations between CO exposure and birth 
outcomes such as preterm birth or cardiac birth defects. The 
epidemiologic studies provide limited evidence of a CO-induced effect 
on preterm births and birth defects, with weak evidence for a decrease 
in birth weight. Animal toxicological studies have found associations 
between perinatal CO exposure and decrements in birth weight, as well 
as other developmental outcomes. The ISA concludes these studies are 
suggestive of a causal relationship between long-term exposures to CO 
and developmental effects and birth outcomes.
    Epidemiologic studies provide evidence of effects on respiratory 
morbidity such as changes in pulmonary function, respiratory symptoms, 
and hospital admissions associated with ambient CO concentrations. A 
limited number of epidemiologic studies considered copollutants such as 
ozone, SO2, and PM in two-pollutant models and found that CO 
risk estimates were generally robust, although this limited evidence 
makes it difficult to disentangle effects attributed to CO itself from 
those of the larger complex air pollution mixture. Controlled human 
exposure studies have not extensively evaluated the effect of CO on 
respiratory morbidity. Animal studies at levels of 50-100 ppm CO show 
preliminary evidence of altered pulmonary vascular remodeling and 
oxidative injury. The ISA concludes that the evidence is suggestive of 
a causal relationship between short-term CO exposure and respiratory 
morbidity, and inadequate to conclude that a causal relationship exists 
between long-term exposure and respiratory morbidity.
    Finally, the ISA concludes that the epidemiologic evidence is 
suggestive of a causal relationship between short-term exposures to CO 
and mortality. Epidemiologic studies provide evidence of an association 
between short-term exposure to CO and mortality, but limited evidence 
is available to evaluate cause-specific mortality outcomes associated 
with CO exposure. In addition, the attenuation of CO risk estimates 
which was often observed in copollutant models contributes to the 
uncertainty as to whether CO is acting alone or as an indicator for 
other combustion-related pollutants. The ISA also concludes that there 
is not likely to be a causal relationship between relevant long-term 
exposures to CO and mortality.
(5) Air Toxics
    Heavy-duty vehicle emissions contribute to ambient levels of air 
toxics known or suspected as human or animal carcinogens, or that have 
noncancer health effects. The population experiences an elevated risk 
of cancer and other noncancer health effects from exposure to the class 
of pollutants known collectively as ``air toxics.'' \257\ These 
compounds include, but are not limited to, benzene, 1,3-butadiene, 
formaldehyde, acetaldehyde, acrolein, diesel particulate matter and 
exhaust organic gases, polycyclic organic matter, and naphthalene. 
These compounds were identified as national or regional risk drivers in 
past National-scale Air Toxics Assessments and have significant 
inventory contributions from mobile sources.\258\
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    \257\ U.S. EPA. 2002 National-Scale Air Toxics Assessment. 
http://www.epa.gov/ttn/atw/nata12002/risksum.html. Docket EPA-HQ-
OAR-2010-0162.
    \258\ U.S. EPA 2009. National-Scale Air Toxics Assessment for 
2002. http://www.epa.gov/ttn/atw/nata2002/. Docket EPA-HQ-OAR-2010-
0162.
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(a) Diesel Exhaust
    Heavy-duty diesel engines emit diesel exhaust, a complex mixture 
composed of carbon dioxide, oxygen, nitrogen, water vapor, carbon 
monoxide, nitrogen compounds, sulfur compounds and numerous low-
molecular-weight hydrocarbons. A number of these gaseous hydrocarbon 
components are individually known to be toxic, including aldehydes, 
benzene and 1,3-butadiene. The diesel particulate matter present in 
diesel exhaust consists of fine particles (< 2.5 [mu]m), including a 
subgroup with a large number of ultrafine particles (< 0.1 [mu]m). 
These particles have a large surface area which makes them an excellent 
medium for adsorbing organics and their small size makes them highly 
respirable. Many of the organic compounds present in the gases and on 
the particles, such as polycyclic organic matter, are individually 
known to have mutagenic and carcinogenic properties.
    Diesel exhaust varies significantly in chemical composition and 
particle sizes between different engine types (heavy-duty, light-duty), 
engine operating conditions (idle, accelerate, decelerate), and fuel 
formulations (high/low sulfur fuel). Also, there are emissions 
differences between on-road and nonroad engines because the nonroad 
engines are generally of older technology. After being emitted in the 
engine exhaust, diesel exhaust undergoes dilution as well as chemical 
and physical changes in the atmosphere. The lifetime for some of the 
compounds present in diesel exhaust ranges from hours to days.\259\
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    \259\ U.S. EPA (2002). Health Assessment Document for Diesel 
Engine Exhaust. EPA/600/8-90/057F Office of Research and 
Development, Washington DC. Retrieved on March 17, 2009 from http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060. Docket EPA-HQ-
OAR-2010-0162.
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(i) Diesel Exhaust: Potential Cancer Effects
    In EPA's 2002 Diesel Health Assessment Document (Diesel HAD),\260\ 
exposure to diesel exhaust was classified as likely to be carcinogenic 
to humans by inhalation from environmental exposures, in accordance 
with the revised draft 1996/1999 EPA cancer guidelines. A number of 
other agencies (National Institute for Occupational Safety and Health, 
the International Agency for Research on Cancer, the World Health 
Organization, California EPA, and the U.S. Department of Health and 
Human Services) have made similar classifications. However, EPA also 
concluded in the Diesel HAD that it is not possible currently to 
calculate a cancer unit risk for diesel exhaust due to a variety of 
factors that limit the

[[Page 74295]]

current studies, such as limited quantitative exposure histories in 
occupational groups investigated for lung cancer.
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    \260\ See U.S. EPA (2002) Diesel HAD, Note 259, at pp. 1-1, 1-2.
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    For the Diesel HAD, EPA reviewed 22 epidemiologic studies on the 
subject of the carcinogenicity of workers exposed to diesel exhaust in 
various occupations, finding increased lung cancer risk, although not 
always statistically significant, in 8 out of 10 cohort studies and 10 
out of 12 case-control studies within several industries. Relative risk 
for lung cancer associated with exposure ranged from 1.2 to 1.5, 
although a few studies show relative risks as high as 2.6. 
Additionally, the Diesel HAD also relied on two independent meta-
analyses, which examined 23 and 30 occupational studies respectively, 
which found statistically significant increases in smoking-adjusted 
relative lung cancer risk associated with exposure to diesel exhaust of 
1.33 to 1.47. These meta-analyses demonstrate the effect of pooling 
many studies and in this case show the positive relationship between 
diesel exhaust exposure and lung cancer across a variety of diesel 
exhaust-exposed occupations.261 262
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    \261\ Bhatia, R., Lopipero, P., Smith, A. (1998). Diesel 
exposure and lung cancer. Epidemiology, 9(1), 84-91. Docket EPA-HQ-
OAR-2010-0162.
    \262\ Lipsett, M. Campleman, S. (1999). Occupational exposure to 
diesel exhaust and lung cancer: a meta-analysis. Am J Public Health, 
80(7), 1009-1017. Docket EPA-HQ-OAR-2010-0162.
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    In the absence of a cancer unit risk, the Diesel HAD sought to 
provide additional insight into the significance of the diesel exhaust-
cancer hazard by estimating possible ranges of risk that might be 
present in the population. An exploratory analysis was used to 
characterize a possible risk range by comparing a typical environmental 
exposure level for highway diesel sources to a selected range of 
occupational exposure levels. The occupationally observed risks were 
then proportionally scaled according to the exposure ratios to obtain 
an estimate of the possible environmental risk. A number of 
calculations are needed to accomplish this, and these can be seen in 
the EPA Diesel HAD. The outcome was that environmental risks from 
diesel exhaust exposure could range from a low of 10-4 to 
10-5 to as high as 10-3, reflecting the range of 
occupational exposures that could be associated with the relative and 
absolute risk levels observed in the occupational studies. Because of 
uncertainties, the analysis acknowledged that the risks could be lower 
than 10-4 or 10-5, and a zero risk from diesel 
exhaust exposure was not ruled out.
(ii) Diesel Exhaust: Other Health Effects
    Noncancer health effects of acute and chronic exposure to diesel 
exhaust emissions are also of concern to the EPA. EPA derived a diesel 
exhaust reference concentration (RfC) from consideration of four well-
conducted chronic rat inhalation studies showing adverse pulmonary 
effects.263 264 265 266 The RfC is 5 [mu]g/m\3\ for diesel 
exhaust as measured by diesel particulate matter. This RfC does not 
consider allergenic effects such as those associated with asthma or 
immunologic effects. There is growing evidence, discussed in the Diesel 
HAD, that exposure to diesel exhaust can exacerbate these effects, but 
the exposure-response data are presently lacking to derive an RfC. The 
EPA Diesel HAD states, ``With [diesel particulate matter] being a 
ubiquitous component of ambient PM, there is an uncertainty about the 
adequacy of the existing [diesel exhaust] noncancer database to 
identify all of the pertinent [diesel exhaust]-caused noncancer health 
hazards.'' (p. 9-19). The Diesel HAD concludes ``that acute exposure to 
[diesel exhaust] has been associated with irritation of the eye, nose, 
and throat, respiratory symptoms (cough and phlegm), and 
neurophysiological symptoms such as headache, lightheadedness, nausea, 
vomiting, and numbness or tingling of the extremities.'' \267\
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    \263\ Ishinishi, N. Kuwabara, N. Takaki, Y., et al. (1988). 
Long-term inhalation experiments on diesel exhaust. In: Diesel 
exhaust and health risks. Results of the HERP studies. Ibaraki, 
Japan: Research Committee for HERP Studies; pp. 11-84. Docket EPA-
HQ-OAR-2010-0162.
    \264\ Heinrich, U., Fuhst, R., Rittinghausen, S., et al. (1995). 
Chronic inhalation exposure of Wistar rats and two different strains 
of mice to diesel engine exhaust, carbon black, and titanium 
dioxide. Inhal Toxicol, 7, 553-556. Docket EPA-HQ-OAR-2010-0162.
    \265\ Mauderly, J.L., Jones, R.K., Griffith, W.C., et al. 
(1987). Diesel exhaust is a pulmonary carcinogen in rats exposed 
chronically by inhalation. Fundam. Appl. Toxicol., 9, 208-221. 
Docket EPA-HQ-OAR-2010-0162.
    \266\ Nikula, K.J., Snipes, M.B., Barr, E.B., et al. (1995). 
Comparative pulmonary toxicities and carcinogenicities of 
chronically inhaled diesel exhaust and carbon black in F344 rats. 
Fundam. Appl. Toxicol, 25, 80-94. Docket EPA-HQ-OAR-2010-0162.
    \267\ See U.S. EPA (2002), Diesel HAD at Note 259, at p. 9-9.
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(iii) Ambient PM2.5 Levels and Exposure to Diesel Exhaust PM
    The Diesel HAD also briefly summarizes health effects associated 
with ambient PM and discusses the EPA's annual PM2.5 NAAQS 
of 15 [mu]g/m\3\. There is a much more extensive body of human data 
showing a wide spectrum of adverse health effects associated with 
exposure to ambient PM, of which diesel exhaust is an important 
component. The PM2.5 NAAQS is designed to provide protection 
from the noncancer and premature mortality effects of PM2.5 
as a whole.
(iv) Diesel Exhaust PM Exposures
    Exposure of people to diesel exhaust depends on their various 
activities, the time spent in those activities, the locations where 
these activities occur, and the levels of diesel exhaust pollutants in 
those locations. The major difference between ambient levels of diesel 
particulate and exposure levels for diesel particulate is that exposure 
accounts for a person moving from location to location, proximity to 
the emission source, and whether the exposure occurs in an enclosed 
environment.
Occupational Exposures
    Occupational exposures to diesel exhaust from mobile sources can be 
several orders of magnitude greater than typical exposures in the non-
occupationally exposed population.
    Over the years, diesel particulate exposures have been measured for 
a number of occupational groups. A wide range of exposures have been 
reported, from 2 [mu]g/m\3\ to 1,280 [mu]g/m\3\, for a variety of 
occupations. As discussed in the Diesel HAD, the National Institute of 
Occupational Safety and Health has estimated a total of 1,400,000 
workers are occupationally exposed to diesel exhaust from on-road and 
nonroad vehicles.
Elevated Concentrations and Ambient Exposures in Mobile Source-Impacted 
Areas
    Regions immediately downwind of highways or truck stops may 
experience elevated ambient concentrations of directly-emitted 
PM2.5 from diesel engines. Due to the unique nature of 
highways and truck stops, emissions from a large number of diesel 
engines are concentrated in a small area. Studies near roadways with 
high truck traffic indicate higher concentrations of components of 
diesel PM than other locations.268 269 270 High ambient 
particle

[[Page 74296]]

concentrations have also been reported near trucking terminals, truck 
stops, and bus garages.271 272 273 Additional discussion of 
exposure and health effects associated with traffic is included below 
in Section VII.B.(5)(j).
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    \268\ Zhu, Y.; Hinds, W.C.; Kim, S.; Shen, S.; Sioutas, C. 
(2002). Study of ultrafine particles near a major highway with 
heavy-duty diesel traffic. Atmospheric Environment 36: 4323-4335. 
Docket EPA-HQ-OAR-2010-0162.
    \269\ Lena, T.S; Ochieng, V.; Holgu[iacute]n-Veras, J.; Kinney, 
P.L. (2002). Elemental carbon and PM2.5 levels in an 
urban community heavily impacted by truck traffic. Environ Health 
Perspect 110: 1009-1015. Docket EPA-HQ-OAR-2010-0162.
    \270\ Soliman, A.S.M.; Jacko, J.B.; Palmer, G.M. (2006). 
Development of an empirical model to estimate real-world fine 
particulate matter emission factors: the Traffic Air Quality model. 
J Air & Waste Manage Assoc 56: 1540-1549. Docket EPA-HQ-OAR-2010-
0162.
    \271\ Davis, M.E.; Smith, T.J.; Laden, F.; Hart, J.E.; Ryan, 
L.M.; Garshick, E. (2006). Modeling particle exposure in U.S. 
trucking terminals. Environ Sci Techol 40: 4226-4232. Docket EPA-HQ-
OAR-2010-0162.
    \272\ Miller, T.L.; Fu, J.S.; Hromis, B.; Storey, J.M. (2007). 
Diesel truck idling emissions--measurements at a PM2.5 hot spot. 
Proceedings of the Annual Conference of the Transportation Research 
Board, paper no. 07-2609. Docket EPA-HQ-OAR-2010-0162.
    \273\ Ramachandran, G.; Paulsen, D.; Watts, W.; Kittelson, D. 
(2005). Mass, surface area, and number metrics in diesel 
occupational exposure assessment. J Environ Monit 7: 728-735. Docket 
EPA-HQ-OAR-2010-0162.
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(b) Benzene
    The EPA's Integrated Risk Information System (IRIS) database lists 
benzene as a known human carcinogen (causing leukemia) by all routes of 
exposure, and concludes that exposure is associated with additional 
health effects, including genetic changes in both humans and animals 
and increased proliferation of bone marrow cells in 
mice.274 275 276 EPA states in its IRIS database that data 
indicate a causal relationship between benzene exposure and acute 
lymphocytic leukemia and suggest a relationship between benzene 
exposure and chronic non-lymphocytic leukemia and chronic lymphocytic 
leukemia. The International Agency for Research on Carcinogens (IARC) 
has determined that benzene is a human carcinogen and the U.S. 
Department of Health and Human Services (DHHS) has characterized 
benzene as a known human carcinogen.277 278
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    \274\ U.S. EPA. 2000. Integrated Risk Information System File 
for Benzene. This material is available electronically at http://www.epagov/iris/subst/0276.htm. Docket EPA-HQ-OAR-2010-0162.
    \275\ International Agency for Research on Cancer. 1982. 
Monographs on the evaluation of carcinogenic risk of chemicals to 
humans, Volume 29. Some industrial chemicals and dyestuffs, World 
Health Organization, Lyon, France, p. 345-389. Docket EPA-HQ-OAR-
2010-0162.
    \276\ Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, 
V.A. 1992. Synergistic action of the benzene metabolite hydroquinone 
on myelopoietic stimulating activity of granulocyte/macrophage 
colony-stimulating factor in vitro, Proc. Natl. Acad. Sci. 89:3691-
3695. Docket EPA-HQ-OAR-2010-0162.
    \277\ See IARC, Note 275, above.
    \278\ U.S. Department of Health and Human Services National 
Toxicology Program 11th Report on Carcinogens available at: http://ntp.niehs.nih.gov/go/16183. Docket EPA-HQ-OAR-2010-0162.
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    A number of adverse noncancer health effects including blood 
disorders, such as preleukemia and aplastic anemia, have also been 
associated with long-term exposure to benzene.279 280 The 
most sensitive noncancer effect observed in humans, based on current 
data, is the depression of the absolute lymphocyte count in 
blood.281 282 In addition, recent work, including studies 
sponsored by the Health Effects Institute (HEI), provides evidence that 
biochemical responses are occurring at lower levels of benzene exposure 
than previously known.283 284 285 286 EPA's IRIS program has 
not yet evaluated these new data.
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    \279\ Aksoy, M. (1989). Hematotoxicity and carcinogenicity of 
benzene. Environ. Health Perspect. 82: 193-197. Docket EPA-HQ-OAR-
2010-0162.
    \280\ Goldstein, B.D. (1988). Benzene toxicity. Occupational 
medicine. State of the Art Reviews. 3: 541-554. Docket EPA-HQ-OAR-
2010-0162.
    \281\ Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. 
Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, M.T. Smith, N. Titenko-
Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes (1996). 
Hematotoxicity among Chinese workers heavily exposed to benzene. Am. 
J. Ind. Med. 29: 236-246. Docket EPA-HQ-OAR-2010-0162.
    \282\ U.S. EPA (2002). Toxicological Review of Benzene 
(Noncancer Effects). Environmental Protection Agency, Integrated 
Risk Information System, Research and Development, National Center 
for Environmental Assessment, Washington DC. This material is 
available electronically at  http://www.epa.gov/iris/ubst/0276.htm. 
Docket EPA-HQ-OAR-2010-0162.
    \283\ Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; 
Melikian, A.; Eastmond, D.; Rappaport, S.; Li, H.; Rupa, D.; 
Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, 
E.; Li, Y.; Mu, R.; Xu, B.; Zhang, X.; Li, K. (2003). HEI Report 
115, Validation & Evaluation of Biomarkers in Workers Exposed to 
Benzene in China. Docket EPA-HQ-OAR-2010-0162.
    \284\ Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et 
al. (2002). Hematological changes among Chinese workers with a broad 
range of benzene exposures. Am. J. Industr. Med. 42: 275-285. Docket 
EPA-HQ-OAR-2010-0162.
    \285\ Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. 
(2004). Hematotoxically in Workers Exposed to Low Levels of Benzene. 
Science 306: 1774-1776. Docket EPA-HQ-OAR-2010-0162.
    \286\ Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism 
in rodents at doses relevant to human exposure from Urban Air. 
Research Reports Health Effect Inst. Report No.113. Docket EPA-HQ-
OAR-2010-0162.
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(c) 1,3-Butadiene
    EPA has characterized 1,3-butadiene as carcinogenic to humans by 
inhalation.287 288 The IARC has determined that 1,3-
butadiene is a human carcinogen and the U.S. DHHS has characterized 
1,3-butadiene as a known human carcinogen.289 290 There are 
numerous studies consistently demonstrating that 1,3-butadiene is 
metabolized into genotoxic metabolites by experimental animals and 
humans. The specific mechanisms of 1,3-butadiene-induced carcinogenesis 
are unknown; however, the scientific evidence strongly suggests that 
the carcinogenic effects are mediated by genotoxic metabolites. Animal 
data suggest that females may be more sensitive than males for cancer 
effects associated with 1,3-butadiene exposure; there are insufficient 
data in humans from which to draw conclusions about sensitive 
subpopulations. 1,3-butadiene also causes a variety of reproductive and 
developmental effects in mice; no human data on these effects are 
available. The most sensitive effect was ovarian atrophy observed in a 
lifetime bioassay of female mice.\291\
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    \287\ U.S. EPA (2002). Health Assessment of 1,3-Butadiene. 
Office of Research and Development, National Center for 
Environmental Assessment, Washington Office, Washington, DC. Report 
No. EPA600-P-98-001F. This document is available electronically at 
http://www.epa.gov/iris/supdocs/buta-sup.pdf. Docket EPA-HQ-OAR-
2010-0162.
    \288\ U.S. EPA (2002). Full IRIS Summary for 1,3-butadiene 
(CASRN 106-99-0). Environmental Protection Agency, Integrated Risk 
Information System (IRIS), Research and Development, National Center 
for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. Docket EPA-HQ-OAR-2010-0162.
    \289\ International Agency for Research on Cancer (1999). 
Monographs on the evaluation of carcinogenic risk of chemicals to 
humans, Volume 71, Re-evaluation of some organic chemicals, 
hydrazine and hydrogen peroxide and Volume 97 (in preparation), 
World Health Organization, Lyon, France. Docket EPA-HQ-OAR-2010-
0162.
    \290\ U.S. Department of Health and Human Services (2005). 
National Toxicology Program 11th Report on Carcinogens available at: 
ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932. Docket EPA-HQ-OAR-2010-0162.
    \291\ Bevan, C.; Stadler, J.C.; Elliot, G.S.; et al. (1996). 
Subchronic toxicity of 4-vinylcyclohexene in rats and mice by 
inhalation. Fundam. Appl. Toxicol. 32:1-10. Docket EPA-HQ-OAR-2010-
0162.
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(d) Formaldehyde
    Since 1987, EPA has classified formaldehyde as a probable human 
carcinogen based on evidence in humans and in rats, mice, hamsters, and 
monkeys.\292\ EPA is currently reviewing recently published 
epidemiological data. For instance, research conducted by the National 
Cancer Institute found an increased risk of nasopharyngeal cancer and 
lymphohematopoietic malignancies such as leukemia among workers exposed 
to formaldehyde.293 294

[[Page 74297]]

In an analysis of the lymphohematopoietic cancer mortality from an 
extended follow-up of these workers, the National Cancer Institute 
confirmed an association between lymphohematopoietic cancer risk and 
peak exposures.\295\ A recent National Institute of Occupational Safety 
and Health study of garment workers also found increased risk of death 
due to leukemia among workers exposed to formaldehyde.\296\ Extended 
follow-up of a cohort of British chemical workers did not find evidence 
of an increase in nasopharyngeal or lymphohematopoietic cancers, but a 
continuing statistically significant excess in lung cancers was 
reported.\297\ Recently, the IARC re-classified formaldehyde as a human 
carcinogen (Group 1).\298\
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    \292\ U.S. EPA (1987). Assessment of Health Risks to Garment 
Workers and Certain Home Residents from Exposure to Formaldehyde, 
Office of Pesticides and Toxic Substances, April 1987. Docket EPA-
HQ-OAR-2010-0162.
    \293\ Hauptmann, M.; Lubin, J. H.; Stewart, P.A.; Hayes, R.B.; 
Blair, A. 2003. Mortality from lymphohematopoetic malignancies among 
workers in formaldehyde industries. Journal of the National Cancer 
Institute 95: 1615-1623. Docket EPA-HQ-OAR-2010-0162.
    \294\ Hauptmann, M.; Lubin, J.H.; Stewart, P.A.; Hayes, R.B.; 
Blair, A. 2004. Mortality from solid cancers among workers in 
formaldehyde industries. American Journal of Epidemiology 159: 1117-
1130. Docket EPA-HQ-OAR-2010-0162.
    \295\ Beane Freeman, L.E.; Blair, A.; Lubin, J.H.; Stewart, 
P.A.; Hayes, R.B.; Hoover, R.N.; Hauptmann, M. 2009. Mortality from 
lymphohematopoietic malignancies among workers in formaldehyde 
industries: The National Cancer Institute cohort. J. National Cancer 
Inst. 101: 751-761. Docket EPA-HQ-OAR-2010-0162.
    \296\ Pinkerton, L.E. 2004. Mortality among a cohort of garment 
workers exposed to formaldehyde: an update. Occup. Environ. Med. 61: 
193-200. Docket EPA-HQ-OAR-2010-0162.
    \297\ Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended 
follow-up of a cohort of British chemical workers exposed to 
formaldehyde. J National Cancer Inst. 95:1608-1615. Docket EPA-HQ-
OAR-2010-0162.
    \298\ International Agency for Research on Cancer. 2006. 
Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol. Volume 
88. (in preparation), World Health Organization, Lyon, France. 
Docket EPA-HQ-OAR-2010-0162.
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    Formaldehyde exposure also causes a range of noncancer health 
effects, including irritation of the eyes (burning and watering of the 
eyes), nose and throat. Effects from repeated exposure in humans 
include respiratory tract irritation, chronic bronchitis and nasal 
epithelial lesions such as metaplasia and loss of cilia. Animal studies 
suggest that formaldehyde may also cause airway inflammation--including 
eosinophil infiltration into the airways. There are several studies 
that suggest that formaldehyde may increase the risk of asthma--
particularly in the young.299 300
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    \299\ Agency for Toxic Substances and Disease Registry (ATSDR). 
1999. Toxicological profile for Formaldehyde. Atlanta, GA: U.S. 
Department of Health and Human Services, Public Health Service. 
http://ww.atsdr.cdc.gov/toxprofiles/tp111.html. Docket EPA-HQ-OAR-
2010-0162.
    \300\ WHO (2002). Concise International Chemical Assessment 
Document 40: Formaldehyde. Published under the joint sponsorship of 
the United Nations Environment Programme, the International Labour 
Organization, and the World Health Organization, and produced within 
the framework of the Inter-Organization Programme for the Sound 
Management of Chemicals. Geneva. Docket EPA-HQ-OAR-2010-0162.
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(e) Acetaldehyde
    Acetaldehyde is classified in EPA's IRIS database as a probable 
human carcinogen, based on nasal tumors in rats, and is considered 
toxic by the inhalation, oral, and intravenous routes.\301\ 
Acetaldehyde is reasonably anticipated to be a human carcinogen by the 
U.S. DHHS in the 11th Report on Carcinogens and is classified as 
possibly carcinogenic to humans (Group 2B) by the 
IARC.302 303 EPA is currently conducting a reassessment of 
cancer risk from inhalation exposure to acetaldehyde.
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    \301\ U.S. EPA. 1991. Integrated Risk Information System File of 
Acetaldehyde. Research and Development, National Center for 
Environmental Assessment, Washington, DC. Available at http://www.epa.gov/iris/subst/0290.htm. Docket EPA-HQ-OAR-2010-0162.
    \302\ U.S. Department of Health and Human Services National 
Toxicology Program 11th Report on Carcinogens available at: 
ntp.niehs.nih.gov/index.cfm?objectid=32BA9724-F1F6-975E-7FCE50709CB4C932. Docket EPA-HQ-OAR-2010-0162.
    \303\ International Agency for Research on Cancer. 1999. Re-
evaluation of some organic chemicals, hydrazine, and hydrogen 
peroxide. IARC Monographs on the Evaluation of Carcinogenic Risk of 
Chemical to Humans, Vol 71. Lyon, France. Docket EPA-HQ-OAR-2010-
0162.
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    The primary noncancer effects of exposure to acetaldehyde vapors 
include irritation of the eyes, skin, and respiratory tract.\304\ In 
short-term (4 week) rat studies, degeneration of olfactory epithelium 
was observed at various concentration levels of acetaldehyde 
exposure.305 306 Data from these studies were used by EPA to 
develop an inhalation reference concentration. Some asthmatics have 
been shown to be a sensitive subpopulation to decrements in functional 
expiratory volume (FEV1 test) and bronchoconstriction upon acetaldehyde 
inhalation.\307\ The agency is currently conducting a reassessment of 
the health hazards from inhalation exposure to acetaldehyde.
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    \304\ See Integrated Risk Information System File of 
Acetaldehyde, Note 301, above.
    \305\ Appleman, L.M., R.A. Woutersen, V.J. Feron, R.N. Hooftman, 
and W.R.F. Notten. 1986. Effects of the variable versus fixed 
exposure levels on the toxicity of acetaldehyde in rats. J. Appl. 
Toxicol. 6: 331-336. Docket EPA-HQ-OAR-2010-0162
    \306\ Appleman, L.M., R.A. Woutersen, and V.J. Feron. 1982. 
Inhalation toxicity of acetaldehyde in rats. I. Acute and subacute 
studies. Toxicology. 23: 293-297. Docket EPA-HQ-OAR-2010-0162.
    \307\ Myou, S.; Fujimura, M.; Nishi K.; Ohka, T.; and Matsuda, 
T. 1993. Aerosolized acetaldehyde induces histamine-mediated 
bronchoconstriction in asthmatics. Am. Rev. Respir.Dis. 148 (4 Pt 
1): 940-3. Docket EPA-HQ-OAR-2010-0162.
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(f) Acrolein
    Acrolein is extremely acrid and irritating to humans when inhaled, 
with acute exposure resulting in upper respiratory tract irritation, 
mucus hypersecretion and congestion. The intense irritancy of this 
carbonyl has been demonstrated during controlled tests in human 
subjects, who suffer intolerable eye and nasal mucosal sensory 
reactions within minutes of exposure.\308\ These data and additional 
studies regarding acute effects of human exposure to acrolein are 
summarized in EPA's 2003 IRIS Human Health Assessment for 
acrolein.\309\ Evidence available from studies in humans indicate that 
levels as low as 0.09 ppm (0.21 mg/m\3\) for five minutes may elicit 
subjective complaints of eye irritation with increasing concentrations 
leading to more extensive eye, nose and respiratory symptoms.\310\ 
Lesions to the lungs and upper respiratory tract of rats, rabbits, and 
hamsters have been observed after subchronic exposure to acrolein.\311\ 
Acute exposure effects in animal studies report bronchial hyper-
responsiveness.\312\ In a recent study, the acute respiratory irritant 
effects of exposure to 1.1 ppm acrolein were more pronounced in mice 
with allergic airway disease by comparison to non-diseased mice which 
also showed decreases in respiratory rate.\313\ Based on these animal 
data and demonstration of similar effects in humans (e.g., reduction in 
respiratory rate), individuals with compromised respiratory function 
(e.g., emphysema, asthma) are expected to be at increased risk of 
developing adverse responses to strong respiratory irritants such as 
acrolein.
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    \308\ U.S. EPA (U.S. Environmental Protection Agency). (2003). 
Toxicological review of acrolein in support of summary information 
on Integrated Risk Information System (IRIS) National Center for 
Environmental Assessment, Washington, DC. EPA/635/R-03/003. p. 10. 
Available online at: http://www.epa.gov/ncea/ris/toxreviews/0364tr.pdf. Docket EPA-HQ-OAR-2010-0162.
    \309\ See U.S. EPA 2003 Toxicological review of acrolein, Note 
308, above.
    \310\ See U.S. EPA 2003 Toxicological review of acrolein, Note 
308, at p. 11.
    \311\ Integrated Risk Information System File of Acrolein. 
Office of Research and Development, National Center for 
Environmental Assessment, Washington, DC. This material is available 
at http://www.epa.gov/iris/subst/0364.htm. Docket EPA-HQ-OAR-2010-
0162.
    \312\ See U.S. 2003 Toxicological review of acrolein, Note 308, 
at p. 15.
    \313\ Morris J.B., Symanowicz P.T., Olsen J.E., et al. 2003. 
Immediate sensory nerve-mediated respiratory responses to irritants 
in healthy and allergic airway-diseased mice. J Appl Physiol 
94(4):1563-1571. Docket EPA-HQ-OAR-2010-0162.
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    EPA determined in 2003 that the human carcinogenic potential of 
acrolein could not be determined because the available data were 
inadequate. No information was available on the carcinogenic effects of

[[Page 74298]]

acrolein in humans and the animal data provided inadequate evidence of 
carcinogenicity.\314\ The IARC determined in 1995 that acrolein was not 
classifiable as to its carcinogenicity in humans.\315\
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    \314\ U.S. EPA. 2003. Integrated Risk Information System File of 
Acrolein. Research and Development, National Center for 
Environmental Assessment, Washington, DC. This material is available 
at http://www.epa.gov/iris/subst/0364.htm Docket EPA-HQ-OAR-2010-
0162.
    \315\ International Agency for Research on Cancer. 1995. 
Monographs on the evaluation of carcinogenic risk of chemicals to 
humans, Volume 63. Dry cleaning, some chlorinated solvents and other 
industrial chemicals, World Health Organization, Lyon, France. 
Docket EPA-HQ-OAR-2010-0162.
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(g) Polycyclic Organic Matter
    Polycyclic organic matter is generally defined as a large class of 
organic compounds which have multiple benzene rings and a boiling point 
greater than 100[deg] Celsius. Many of the compounds included in the 
class of compounds known as polycyclic organic matter are classified by 
EPA as probable human carcinogens based on animal data. One of these 
compounds, naphthalene, is discussed separately below. Polycyclic 
aromatic hydrocarbons are a subset of polycyclic organic matter that 
contains only hydrogen and carbon atoms. A number of polycyclic 
aromatic hydrocarbons are known or suspected carcinogens. Recent 
studies have found that maternal exposures to polycyclic aromatic 
hydrocarbons (a subclass of polycyclic organic matter) in a population 
of pregnant women were associated with several adverse birth outcomes, 
including low birth weight and reduced length at birth, as well as 
impaired cognitive development at age three.316 317 EPA has 
not yet evaluated these recent studies.
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    \316\ Perera, F.P.; Rauh, V.; Tsai, W-Y.; et al. (2002). Effect 
of transplacental exposure to environmental pollutants on birth 
outcomes in a multiethnic population. Environ Health Perspect. 111: 
201-205. Docket EPA-HQ-OAR-2010-0162.
    \317\ Perera, F.P.; Rauh, V.; Whyatt, R.M.; Tsai, W.Y.; Tang, 
D.; Diaz, D.; Hoepner, L.; Barr, D.; Tu, Y.H.; Camann, D.; Kinney, 
P. (2006). Effect of prenatal exposure to airborne polycyclic 
aromatic hydrocarbons on neurodevelopment in the first 3 years of 
life among inner-city children. Environ Health Perspect 114: 1287-
1292. Docket EPA-HQ-OAR-2010-0162.
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(h) Naphthalene
    Naphthalene is found in small quantities in gasoline and diesel 
fuels. Naphthalene emissions have been measured in larger quantities in 
both gasoline and diesel exhaust compared with evaporative emissions 
from mobile sources, indicating it is primarily a product of 
combustion. EPA released an external review draft of a reassessment of 
the inhalation carcinogenicity of naphthalene based on a number of 
recent animal carcinogenicity studies.\318\ The draft reassessment 
completed external peer review.\319\ Based on external peer review 
comments received, additional analyses are being undertaken. This 
external review draft does not represent official agency opinion and 
was released solely for the purposes of external peer review and public 
comment. The National Toxicology Program listed naphthalene as 
``reasonably anticipated to be a human carcinogen'' in 2004 on the 
basis of bioassays reporting clear evidence of carcinogenicity in rats 
and some evidence of carcinogenicity in mice.\320\ California EPA has 
released a new risk assessment for naphthalene, and the IARC has 
reevaluated naphthalene and re-classified it as Group 2B: possibly 
carcinogenic to humans.\321\ Naphthalene also causes a number of 
chronic non-cancer effects in animals, including abnormal cell changes 
and growth in respiratory and nasal tissues.\322\
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    \318\ U. S. EPA. 2004. Toxicological Review of Naphthalene 
(Reassessment of the Inhalation Cancer Risk), Environmental 
Protection Agency, Integrated Risk Information System, Research and 
Development, National Center for Environmental Assessment, 
Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/436.htm. Docket EPA-HQ-OAR-2010-0162.
    \319\ Oak Ridge Institute for Science and Education. (2004). 
External Peer Review for the IRIS Reassessment of the Inhalation 
Carcinogenicity of Naphthalene. August 2004. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=84403. Docket EPA-HQ-OAR-2010-0162.
    \320\ National Toxicology Program (NTP). (2004). 11th Report on 
Carcinogens. Public Health Service, U.S. Department of Health and 
Human Services, Research Triangle Park, NC. Available from: http://ntp-server.niehs.nih.gov. Docket EPA-HQ-OAR-2010-0162.
    \321\ International Agency for Research on Cancer. (2002). 
Monographs on the Evaluation of the Carcinogenic Risk of Chemicals 
for Humans. Vol. 82. Lyon, France. Docket EPA-HQ-OAR-2010-0162.
    \322\ U.S. EPA. 1998. Toxicological Review of Naphthalene, 
Environmental Protection Agency, Integrated Risk Information System, 
Research and Development, National Center for Environmental 
Assessment, Washington, DC. This material is available 
electronically at http://www.epa.gov/iris/subst/0436.htm. Docket 
EPA-HQ-OAR-2010-0162.
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(i) Other Air Toxics
    In addition to the compounds described above, other compounds in 
gaseous hydrocarbon and PM emissions from heavy-duty vehicles will be 
affected by this proposal. Mobile source air toxic compounds that would 
potentially be impacted include ethylbenzene, propionaldehyde, toluene, 
and xylene. Information regarding the health effects of these compounds 
can be found in EPA's IRIS database.\323\
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    \323\ U.S. EPA Integrated Risk Information System (IRIS) 
database is available at: http://www.epa.gov/iris.
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(j) Exposure and Health Effects Associated With Traffic
    Populations who live, work, or attend school near major roads 
experience elevated exposure concentrations to a wide range of air 
pollutants, as well as higher risks for a number of adverse health 
effects. While the previous sections of this preamble have focused on 
the health effects associated with individual criteria pollutants or 
air toxics, this section discusses the mixture of different exposures 
near major roadways, rather than the effects of any single pollutant. 
As such, this section emphasizes traffic-related air pollution, in 
general, as the relevant indicator of exposure rather than any 
particular pollutant.
    Concentrations of many traffic-generated air pollutants are 
elevated for up to 300-500 meters downwind of roads with high traffic 
volumes.\324\ Numerous sources on roads contribute to elevated roadside 
concentrations, including exhaust and evaporative emissions, and 
resuspension of road dust and tire and brake wear. Concentrations of 
several criteria and hazardous air pollutants are elevated near major 
roads. Furthermore, different semi-volatile organic compounds and 
chemical components of particulate matter, including elemental carbon, 
organic material, and trace metals, have been reported at higher 
concentrations near major roads.
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    \324\ Zhou, Y.; Levy, J.I. (2007). Factors influencing the 
spatial extent of mobile source air pollution impacts: A meta-
analysis. BMC Public Health 7: 89. doi:10.1186/1471-2458-7-89 Docket 
EPA-HQ-OAR-2010-0162.
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    Populations near major roads experience greater risk of certain 
adverse health effects. The Health Effects Institute published a report 
on the health effects of traffic-related air pollution.\325\ It 
concluded that evidence is ``sufficient to infer the presence of a 
causal association'' between traffic exposure and exacerbation of 
childhood asthma symptoms. The HEI report also concludes that the 
evidence is either ``sufficient'' or ``suggestive but not sufficient'' 
for a causal association between traffic exposure and new childhood 
asthma cases. A review of asthma studies by Salam et al. (2008)

[[Page 74299]]

reaches similar conclusions.\326\ The HEI report also concludes that 
there is ``suggestive'' evidence for pulmonary function deficits 
associated with traffic exposure, but concluded that there is 
``inadequate and insufficient'' evidence for causal associations with 
respiratory health care utilization, adult-onset asthma, chronic 
obstructive pulmonary disease symptoms, and allergy. A review by 
Holguin (2008) notes that the effects of traffic on asthma may be 
modified by nutrition status, medication use, and genetic factors.\327\
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    \325\ HEI Panel on the Health Effects of Air Pollution. (2010). 
Traffic-related air pollution: A critical review of the literature 
on emissions, exposure, and health effects. [Online at http://www.healtheffects.org.] Docket EPA-HQ-OAR-2010-0162.
    \326\ Salam, M.T.; Islam, T.; Gilliland, F.D. (2008). Recent 
evidence for adverse effects of residential proximity to traffic 
sources on asthma. Current Opin Pulm Med 14: 3-8. Docket EPA-HQ-OAR-
2010-0162.
    \327\ Holguin, F. (2008). Traffic, outdoor air pollution, and 
asthma. Immunol Allergy Clinics North Am 28: 577-588. Docket EPA-HQ-
OAR-2010-0162.
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    The HEI report also concludes that evidence is ``suggestive'' of a 
causal association between traffic exposure and all-cause and 
cardiovascular mortality. There is also evidence of an association 
between traffic-related air pollutants and cardiovascular effects such 
as changes in heart rhythm, heart attack, and cardiovascular disease. 
The HEI report characterizes this evidence as ``suggestive'' of a 
causal association, and an independent epidemiological literature 
review by Adar and Kaufman (2007) concludes that there is ``consistent 
evidence'' linking traffic-related pollution and adverse cardiovascular 
health outcomes.\328\
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    \328\ Adar, S.D.; Kaufman, J.D. (2007). Cardiovascular disease 
and air pollutants: Evaluating and improving epidemiological data 
implicating traffic exposure. Inhal Toxicol 19: 135-149. Docket EPA-
HQ-OAR-2010-0162.
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    Some studies have reported associations between traffic exposure 
and other health effects, such as birth outcomes (e.g., low birth 
weight) and childhood cancer. The HEI report concludes that there is 
currently ``inadequate and insufficient'' evidence for a causal 
association between these effects and traffic exposure. A review by 
Raaschou-Nielsen and Reynolds (2006) concluded that evidence of an 
association between childhood cancer and traffic-related air pollutants 
is weak, but noted the inability to draw firm conclusions based on 
limited evidence.\329\
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    \329\ Raaschou-Nielsen, O.; Reynolds, P. (2006). Air pollution 
and childhood cancer: A review of the epidemiological literature. 
Int J Cancer 118: 2920-2929. Docket EPA-HQ-OAR-2010-0162.
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    There is a large population in the United States living in close 
proximity of major roads. According to the Census Bureau's American 
Housing Survey for 2007, approximately 20 million residences in the 
United States, 15.6% of all homes, are located within 300 feet (91 m) 
of a highway with 4+ lanes, a railroad, or an airport.\330\ Therefore, 
at current population of approximately 309 million, assuming that 
population and housing are similarly distributed, there are over 48 
million people in the United States living near such sources. The HEI 
report also notes that in two North American cities, Los Angeles and 
Toronto, over 40% of each city's population live within 500 meters of a 
highway or 100 meters of a major road. It also notes that about 33% of 
each city's population resides within 50 meters of major roads. 
Together, the evidence suggests that a large U.S. population lives in 
areas with elevated traffic-related air pollution.
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    \330\ U.S. Census Bureau (2008). American Housing Survey for the 
United States in 2007. Series H-150 (National Data), Table 1A-7. 
[Accessed at http://www.census.gov/hhes/www/housing/ahs/ahs07/ahs07.html on January 22, 2009] Docket EPA-HQ-OAR-2010-0162.
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    People living near roads are often socioeconomically disadvantaged. 
According to the 2007 American Housing Survey, a renter-occupied 
property is over twice as likely as an owner-occupied property to be 
located near a highway with 4+ lanes, railroad or airport. In the same 
survey, the median household income of rental housing occupants was 
less than half that of owner-occupants ($28,921/$59,886). Numerous 
studies in individual urban areas report higher levels of traffic-
related air pollutants in areas with high minority or poor 
populations.331 332 333
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    \331\ Lena, T.S.; Ochieng, V.; Carter, M.; Holgu[iacute]n-Veras, 
J.; Kinney, P.L. (2002). Elemental carbon and PM2.5 levels in an 
urban community heavily impacted by truck traffic. Environ Health 
Perspect 110: 1009-1015. Docket EPA-HQ-OAR-2010-0162.
    \332\ Wier, M.; Sciammas, C.; Seto, E.; Bhatia, R.; Rivard, T. 
(2009). Health, traffic, and environmental justice: collaborative 
research and community action in San Francisco, California. Am J 
Public Health 99: S499-S504. Docket EPA-HQ-OAR-2010-0162.
    \333\ Forkenbrock, D.J. and L.A. Schweitzer, Environmental 
Justice and Transportation Investment Policy. Iowa City: University 
of Iowa, 1997. Docket EPA-HQ-OAR-2010-0162.
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    Students may also be exposed in situations where schools are 
located near major roads. In a study of nine metropolitan areas across 
the United States, Appatova et al. (2008) found that on average greater 
than 33% of schools were located within 400 m of an Interstate, U.S., 
or State highway, while 12% were located within 100 m.\334\ The study 
also found that among the metropolitan areas studied, schools in the 
Eastern United States were more often sited near major roadways than 
schools in the Western United States.
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    \334\ Appatova, A.S.; Ryan, P.H.; LeMasters, G.K.; Grinshpun, 
S.A. (2008). Proximal exposure of public schools and students to 
major roadways: A nationwide U.S. survey. J Environ Plan Mgmt Docket 
EPA-HQ-OAR-2010-0162.
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    Demographic studies of students in schools near major roadways 
suggest that this population is more likely than the general student 
population to be of non-white race or Hispanic ethnicity, and more 
often live in low socioeconomic status locations.335 336 337 
There is some inconsistency in the evidence, which may be due to 
different local development patterns and measures of traffic and 
geographic scale used in the studies.\334\
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    \335\ Green, R.S.; Smorodinsky, S.; Kim, J.J.; McLaughlin, R.; 
Ostro, B. (2004). Proximity of California public schools to busy 
roads. Environ Health Perspect 112: 61-66. Docket EPA-HQ-OAR-2010-
0162.
    \336\ Houston, D.; Ong, P.; Wu, J.; Winer, A. (2006). Proximity 
of licensed child care facilities to near-roadway vehicle pollution. 
Am J Public Health 96: 1611-1617. Docket EPA-HQ-OAR-2010-0162.
    \337\ Wu, Y.; Batterman, S. (2006). Proximity of schools in 
Detroit, Michigan to automobile and truck traffic. J Exposure Sci 
Environ Epidemiol 16: 457-470. Docket EPA-HQ-OAR-2010-0162.
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C. Environmental Effects of Non-GHG Pollutants

    In this section we discuss some of the environmental effects of PM 
and its precursors such as visibility impairment, atmospheric 
deposition, and materials damage and soiling, as well as environmental 
effects associated with the presence of ozone in the ambient air, such 
as impacts on plants, including trees, agronomic crops and urban 
ornamentals, and environmental effects associated with air toxics.
(1) Visibility
    Visibility can be defined as the degree to which the atmosphere is 
transparent to visible light.\338\ Visibility impairment is caused by 
light scattering and absorption by suspended particles and gases. 
Visibility is important because it has direct significance to people's 
enjoyment of daily activities in all parts of the country. Individuals 
value good visibility for the well-being it provides them directly, 
where they live and work, and in places where they enjoy recreational 
opportunities. Visibility is also highly valued in significant natural 
areas, such as national parks and wilderness areas, and special 
emphasis is given to protecting visibility in these

[[Page 74300]]

areas. For more information on visibility see the final 2009 PM 
ISA.\339\
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    \338\ National Research Council, 1993. Protecting Visibility in 
National Parks and Wilderness Areas. National Academy of Sciences 
Committee on Haze in National Parks and Wilderness Areas. National 
Academy Press, Washington, DC. Docket EPA-HQ-OAR-2010-0162. This 
book can be viewed on the National Academy Press Web site at http://www.nap.edu/books/0309048443/html/.
    \339\ See U.S. EPA 2009. Final PM ISA, Note 243.
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    EPA is pursuing a two-part strategy to address visibility. First, 
EPA has concluded that PM2.5 causes adverse effects on visibility in 
various locations, depending on PM concentrations and factors such as 
chemical composition and average relative humidity, and has set 
secondary PM2.5 standards.\340\ The secondary PM2.5 
standards act in conjunction with the regional haze program. EPA's 
regional haze rule (64 FR 35714) was put in place in July 1999 to 
protect the visibility in Mandatory Class I Federal areas. There are 
156 national parks, forests and wilderness areas categorized as 
Mandatory Class I Federal areas (62 FR 38680-38681, July 18, 
1997).\341\ Visibility can be said to be impaired in both PM2.5 
nonattainment areas and Mandatory Class I Federal areas.
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    \340\ The existing annual primary and secondary PM2.5 
standards have been remanded and are being addressed in the 
currently ongoing PM NAAQS review.
    \341\ These areas are defined in CAA section 162 as those 
national parks exceeding 6,000 acres, wilderness areas and memorial 
parks exceeding 5,000 acres, and all international parks which were 
in existence on August 7, 1977.
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(2) Plant and Ecosystem Effects of Ozone
    Elevated ozone levels contribute to environmental effects, with 
impacts to plants and ecosystems being of most concern. Ozone can 
produce both acute and chronic injury in sensitive species depending on 
the concentration level and the duration of the exposure. Ozone effects 
also tend to accumulate over the growing season of the plant, so that 
even low concentrations experienced for a longer duration have the 
potential to create chronic stress on vegetation. Ozone damage to 
plants includes visible injury to leaves and impaired photosynthesis, 
both of which can lead to reduced plant growth and reproduction, 
resulting in reduced crop yields, forestry production, and use of 
sensitive ornamentals in landscaping. In addition, the impairment of 
photosynthesis, the process by which the plant makes carbohydrates (its 
source of energy and food), can lead to a subsequent reduction in root 
growth and carbohydrate storage below ground, resulting in other, more 
subtle plant and ecosystems impacts.
    These latter impacts include increased susceptibility of plants to 
insect attack, disease, harsh weather, interspecies competition and 
overall decreased plant vigor. The adverse effects of ozone on forest 
and other natural vegetation can potentially lead to species shifts and 
loss from the affected ecosystems, resulting in a loss or reduction in 
associated ecosystem goods and services. Lastly, visible ozone injury 
to leaves can result in a loss of aesthetic value in areas of special 
scenic significance like national parks and wilderness areas. The final 
2006 Ozone Air Quality Criteria Document presents more detailed 
information on ozone effects on vegetation and ecosystems.
(3) Atmospheric Deposition
    Wet and dry deposition of ambient particulate matter delivers a 
complex mixture of metals (e.g., mercury, zinc, lead, nickel, aluminum, 
cadmium), organic compounds (e.g., polycyclic organic matter, dioxins, 
furans) and inorganic compounds (e.g., nitrate, sulfate) to terrestrial 
and aquatic ecosystems. The chemical form of the compounds deposited 
depends on a variety of factors including ambient conditions (e.g., 
temperature, humidity, oxidant levels) and the sources of the material. 
Chemical and physical transformations of the compounds occur in the 
atmosphere as well as the media onto which they deposit. These 
transformations in turn influence the fate, bioavailability and 
potential toxicity of these compounds. Atmospheric deposition has been 
identified as a key component of the environmental and human health 
hazard posed by several pollutants including mercury, dioxin and 
PCBs.\342\
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    \342\ U.S. EPA (2000). Deposition of Air Pollutants to the Great 
Waters: Third Report to Congress. Office of Air Quality Planning and 
Standards. EPA-453/R-00-0005. Docket EPA-HQ-OAR-2010-0162.
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    Adverse impacts on water quality can occur when atmospheric 
contaminants deposit to the water surface or when material deposited on 
the land enters a waterbody through runoff. Potential impacts of 
atmospheric deposition to waterbodies include those related to both 
nutrient and toxic inputs. Adverse effects to human health and welfare 
can occur from the addition of excess nitrogen via atmospheric 
deposition. The nitrogen-nutrient enrichment contributes to toxic algae 
blooms and zones of depleted oxygen, which can lead to fish kills, 
frequently in coastal waters. Deposition of heavy metals or other 
toxics may lead to the human ingestion of contaminated fish, impairment 
of drinking water, damage to the marine ecology, and limits to 
recreational uses. Several studies have been conducted in U.S. coastal 
waters and in the Great Lakes Region in which the role of ambient PM 
deposition and runoff is investigated.343 344 345 346 347
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    \343\ U.S. EPA (2004). National Coastal Condition Report II. 
Office of Research and Development/Office of Water. EPA-620/R-03/
002. Docket EPA-HQ-OAR-2010-0162.
    \344\ Gao, Y., E.D. Nelson, M.P. Field, et al. 2002. 
Characterization of atmospheric trace elements on PM2.5 particulate 
matter over the New York-New Jersey harbor estuary. Atmos. Environ. 
36: 1077-1086. Docket EPA-HQ-OAR-2010-0162.
    \345\ Kim, G., N. Hussain, J.R. Scudlark, and T.M. Church. 2000. 
Factors influencing the atmospheric depositional fluxes of stable 
Pb, 210Pb, and 7Be into Chesapeake Bay. J. Atmos. Chem. 36: 65-79. 
Docket EPA-HQ-OAR-2010-0162.
    \346\ Lu, R., R.P. Turco, K. Stolzenbach, et al. 2003. Dry 
deposition of airborne trace metals on the Los Angeles Basin and 
adjacent coastal waters. J. Geophys. Res. 108(D2, 4074): AAC 11-1 to 
11-24. Docket EPA-HQ-OAR-2010-0162.
    \347\ Marvin, C.H., M.N. Charlton, E.J. Reiner, et al. 2002. 
Surficial sediment contamination in Lakes Erie and Ontario: A 
comparative analysis. J. Great Lakes Res. 28(3): 437-450. Docket 
EPA-HQ-OAR-2010-0162.
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    Atmospheric deposition of nitrogen and sulfur contributes to 
acidification, altering biogeochemistry and affecting animal and plant 
life in terrestrial and aquatic ecosystems across the United States. 
The sensitivity of terrestrial and aquatic ecosystems to acidification 
from nitrogen and sulfur deposition is predominantly governed by 
geology. Prolonged exposure to excess nitrogen and sulfur deposition in 
sensitive areas acidifies lakes, rivers and soils. Increased acidity in 
surface waters creates inhospitable conditions for biota and affects 
the abundance and nutritional value of preferred prey species, 
threatening biodiversity and ecosystem function. Over time, acidifying 
deposition also removes essential nutrients from forest soils, 
depleting the capacity of soils to neutralize future acid loadings and 
negatively affecting forest sustainability. Major effects include a 
decline in sensitive forest tree species, such as red spruce (Picea 
rubens) and sugar maple (Acer saccharum), and a loss of biodiversity of 
fishes, zooplankton, and macro invertebrates.
    In addition to the role nitrogen deposition plays in acidification, 
nitrogen deposition also leads to nutrient enrichment and altered 
biogeochemical cycling. In aquatic systems increased nitrogen can alter 
species assemblages and cause eutrophication. In terrestrial systems 
nitrogen loading can lead to loss of nitrogen sensitive lichen species, 
decreased biodiversity of grasslands, meadows and other sensitive 
habitats, and increased potential for invasive species. For a broader 
explanation of the topics treated here, refer to the description in 
Section 7.1.2 of the draft RIA.

[[Page 74301]]

    Adverse impacts on soil chemistry and plant life have been observed 
for areas heavily influenced by atmospheric deposition of nutrients, 
metals and acid species, resulting in species shifts, loss of 
biodiversity, forest decline and damage to forest productivity. 
Potential impacts also include adverse effects to human health through 
ingestion of contaminated vegetation or livestock (as in the case for 
dioxin deposition), reduction in crop yield, and limited use of land 
due to contamination.
    Atmospheric deposition of pollutants can reduce the aesthetic 
appeal of buildings and culturally important articles through soiling, 
and can contribute directly (or in conjunction with other pollutants) 
to structural damage by means of corrosion or erosion. Atmospheric 
deposition may affect materials principally by promoting and 
accelerating the corrosion of metals, by degrading paints, and by 
deteriorating building materials such as concrete and limestone. 
Particles contribute to these effects because of their electrolytic, 
hygroscopic, and acidic properties, and their ability to adsorb 
corrosive gases (principally sulfur dioxide).
(4) Environmental Effects of Air Toxics
    Emissions from producing, transporting and combusting fuel 
contribute to ambient levels of pollutants that contribute to adverse 
effects on vegetation. Volatile organic compounds, some of which are 
considered air toxics, have long been suspected to play a role in 
vegetation damage.\348\ In laboratory experiments, a wide range of 
tolerance to VOCs has been observed.\349\ Decreases in harvested seed 
pod weight have been reported for the more sensitive plants, and some 
studies have reported effects on seed germination, flowering and fruit 
ripening. Effects of individual VOCs or their role in conjunction with 
other stressors (e.g., acidification, drought, temperature extremes) 
have not been well studied. In a recent study of a mixture of VOCs 
including ethanol and toluene on herbaceous plants, significant effects 
on seed production, leaf water content and photosynthetic efficiency 
were reported for some plant species.\350\
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    \348\ U.S. EPA. 1991. Effects of organic chemicals in the 
atmosphere on terrestrial plants. EPA/600/ 3-91/001. Docket EPA-HQ-
OAR-2010-0162.
    \349\ Cape JN, ID Leith, J Binnie, J Content, M Donkin, M 
Skewes, DN Price AR Brown, AD Sharpe. 2003. Effects of VOCs on 
herbaceous plants in an open-top chamber experiment. Environ. 
Pollut. 124:341-343. Docket EPA-HQ-OAR-2010-0162.
    \350\ Cape JN, ID Leith, J Binnie, J Content, M Donkin, M 
Skewes, DN Price AR Brown, AD Sharpe. 2003. Effects of VOCs on 
herbaceous plants in an open-top chamber experiment. Environ. 
Pollut. 124:341-343. Docket EPA-HQ-OAR-2010-0162.
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    Research suggests an adverse impact of vehicle exhaust on plants, 
which has in some cases been attributed to aromatic compounds and in 
other cases to nitrogen oxides.351 352 353 The impacts of 
VOCs on plant reproduction may have long-term implications for 
biodiversity and survival of native species near major roadways. Most 
of the studies of the impacts of VOCs on vegetation have focused on 
short-term exposure and few studies have focused on long-term effects 
of VOCs on vegetation and the potential for metabolites of these 
compounds to affect herbivores or insects.
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    \351\ Viskari E-L. 2000. Epicuticular wax of Norway spruce 
needles as indicator of traffic pollutant deposition. Water, Air, 
and Soil Pollut. 121:327-337. Docket EPA-HQ-OAR-2010-0162.
    \352\ Ugrekhelidze D, F Korte, G Kvesitadze. 1997. Uptake and 
transformation of benzene and toluene by plant leaves. Ecotox. 
Environ. Safety 37:24-29. Docket EPA-HQ-OAR-2010-0162.
    \353\ Kammerbauer H, H Selinger, R Rommelt, A Ziegler-Jons, D 
Knoppik, B Hock. 1987. Toxic components of motor vehicle emissions 
for the spruce Picea abies. Environ. Pollut. 48:235-243. Docket EPA-
HQ-OAR-2010-0162.
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D. Air Quality Impacts of Non-GHG Pollutants

(1) Current Levels of Non-GHG Pollutants
    This proposal may have impacts on ambient concentrations of 
criteria and air toxic pollutants. Nationally, levels of 
PM2.5, ozone, NOX, SOX, CO and air 
toxics are declining.\354\ However, approximately 127 million people 
lived in counties that exceeded any NAAQS in 2008.\355\ These numbers 
do not include the people living in areas where there is a future risk 
of failing to maintain or attain the NAAQS. It is important to note 
that these numbers do not account for potential SO2, 
NO2 or Pb nonattainment areas which have not yet been 
designated. Also, EPA is currently reviewing the standards for PM and 
CO, and those standards could be made more protective, which would 
increase the number of people living in nonattainment areas.
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    \354\ U.S. EPA (2010). Our Nation's Air: Status and Trends 
through 2008. Office of Air Quality Planning and Standards, Research 
Triangle Park, NC. Publication No. EPA 454/R-09-002. http://www.epa.gov/airtrends/2010/. Docket EPA-HQ-OAR-2010-0162.
    \355\ See U.S. EPA Trends, Note 354.
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    Further, the majority of Americans continue to be exposed to 
ambient concentrations of air toxics at levels which have the potential 
to cause adverse health effects.356 357 The levels of air 
toxics to which people are exposed vary depending on where people live 
and work and the kinds of activities in which they engage, as discussed 
in detail in U.S. EPA's recent mobile source air toxics rule.\358\
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    \356\ U.S. Environmental Protection Agency (2007). Control of 
Hazardous Air Pollutants from Mobile Sources; Final Rule. 72 FR 
8434, February 26, 2007.
    \357\ See U.S. EPA 2010, Light-Duty 2012-2016 MY Vehicle Rule, 
Note 6.
    \358\ See U.S. EPA 2007, Note 356.
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(2) Impacts of Proposed Standards on Future Ambient Concentrations of 
PM2.5, Ozone and Air Toxics
    Full-scale photochemical air quality modeling is necessary to 
accurately project levels of criteria pollutants and air toxics. For 
the final rulemaking, a national-scale air quality modeling analysis 
will be performed to analyze the impacts of the standards on 
PM2.5, ozone, and selected air toxics (i.e., benzene, 
formaldehyde, acetaldehyde, acrolein and 1,3-butadiene). The length of 
time needed to prepare the necessary emissions inventories, in addition 
to the processing time associated with the modeling itself, has 
precluded us from performing air quality modeling for this proposal.
    Sections VII.A and VII.B of the preamble present projections of the 
changes in criteria pollutant and air toxics emissions due to the 
proposed vehicle standards; the basis for those estimates is set out in 
Chapter 6 of the draft RIA. The atmospheric chemistry related to 
ambient concentrations of PM2.5, ozone and air toxics is 
very complex, and making predictions based solely on emissions changes 
is extremely difficult. However, based on the magnitude of the 
emissions changes predicted to result from the proposed standards, EPA 
expects that there will be a relatively small change in ambient air 
quality, pending a more comprehensive analysis for the final 
rulemaking.
    For the final rulemaking, EPA intends to use a 2005-based Community 
Multi-scale Air Quality (CMAQ) modeling platform as the tool for the 
air quality modeling. The CMAQ modeling system is a comprehensive 
three-dimensional grid-based Eulerian air quality model designed to 
estimate the formation and fate of oxidant precursors, primary and 
secondary PM concentrations and deposition, and air toxics, over 
regional and urban spatial scales (e.g., over the contiguous United 
States).359 360 361 362

[[Page 74302]]

The CMAQ model is a well-known and well-established tool and is 
commonly used by EPA for regulatory analyses, for instance the recent 
ozone NAAQS proposal, and by States in developing attainment 
demonstrations for their State Implementation Plans.\363\ The CMAQ 
model version 4.7 was most recently peer-reviewed in February of 2009 
for the U.S. EPA.\364\
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    \359\ U.S. Environmental Protection Agency, Byun, D.W., and 
Ching, J.K.S., Eds, 1999. Science algorithms of EPA Models-3 
Community Multiscale Air Quality (CMAQ modeling system, EPA/600/R-
99/030, Office of Research and Development). Docket EPA-HQ-OAR-2010-
0162.
    \360\ Byun, D.W., and Schere, K.L., 2006. Review of the 
Governing Equations, Computational Algorithms, and Other Components 
of the Models-3 Community Multiscale Air Quality (CMAQ) Modeling 
System, J. Applied Mechanics Reviews, 59 (2), 51-77. Docket EPA-HQ-
OAR-2010-0162.
    \361\ Dennis, R.L., Byun, D.W., Novak, J.H., Galluppi, K.J., 
Coats, C.J., and Vouk, M.A., 1996. The next generation of integrated 
air quality modeling: EPA's Models-3, Atmospheric Environment, 30, 
1925-1938. Docket EPA-HQ-OAR-2010-0162.
    \362\ Carlton, A., Bhave, P., Napelnok, S., Edney, E., Sarwar, 
G., Pinder, R., Pouliot, G., and Houyoux, M. Model Representation of 
Secondary Organic Aerosol in CMAQv4.7. Ahead of Print in 
Environmental Science and Technology. Accessed at: http://pubs.acs.org/doi/abs/10.1021/es100636q?prevSearch=CMAQ&searchHistoryKey Docket EPA-HQ-OAR-2010-
0162.
    \363\ U.S. EPA (2007). Regulatory Impact Analysis of the 
Proposed Revisions to the National Ambient Air Quality Standards for 
Ground-Level Ozone. EPA document number 442/R-07-008, July 2007. 
Docket EPA-HQ-OAR-2010-0162
    \364\ Allen, D. et al. (2009). Report on the Peer Review of the 
Atmospheric Modeling and Analysis Division, National Exposure 
Research Laboratory, Office of Research and Development, U.S. EPA. 
http://www.epa.gov/asmdnerl/peer/reviewdocs.html. Docket EPA-HQ-OAR-
2010-0162.
_____________________________________-

    CMAQ includes many science modules that simulate the emission, 
production, decay, deposition and transport of organic and inorganic 
gas-phase and particle-phase pollutants in the atmosphere. EPA intends 
to use the most recent version of CMAQ which reflects updates to 
version 4.7 to improve the underlying science. These include aqueous 
chemistry mass conservation improvements, improved vertical convective 
mixing and lowered CB05 mechanism unit yields for acrolein from 1,3-
butadiene tracer reactions which were updated to be consistent with 
laboratory measurements.

VIII.What are the agencies' estimated cost, economic, and other impacts 
of the proposed program?

    In this section, we present the costs and impacts of the proposed 
HD National Program. It is important to note that NHTSA's proposed fuel 
consumption standards and EPA's proposed GHG standards would both be in 
effect, and each would lead to average fuel economy increases and GHG 
emission reductions. The two agencies' proposed standards would 
comprise the HD National Program.
    The net benefits of the proposed HD National Program consist of the 
effects of the program on:
     The vehicle program costs (costs of complying with the 
vehicle CO2 standards)
     Fuel savings associated with reduced fuel usage resulting 
from the program
     The economic value of reductions in greenhouse gas 
emissions,
     The reductions in other (non-GHG) pollutants,
     Costs associated with increases in noise, congestion, and 
accidents resulting from increased vehicle use,
     The economic value of improvements in U.S. energy security 
impacts,
     Benefits associated with increased vehicle use due to the 
``rebound'' effect.
    We also present the cost-effectiveness of the standards, or the 
cost per ton of emissions reduced. A few effects of the program, such 
as the effects on other pollutants, are not included here. We plan to 
add the effects of other pollutants to the analysis for the final 
rules.
    The program may have other effects that are not included here. The 
agencies seek comment on whether any costs or benefits are omitted from 
this analysis, so that they can be explicitly recognized in the final 
rules. In particular, as discussed in Section III and in Chapter 2 of 
the draft RIA, the technology cost estimates developed here take into 
account the costs to hold other vehicle attributes, such as size and 
performance, constant. In addition, the analysis assumes that the full 
technology costs are passed along to vehicle buyers. With these 
assumptions, because welfare losses are monetary estimates of how much 
buyers would have to be compensated to be made as well off as in the 
absence of the change,\365\ the price increase measures the loss to the 
buyer.\366\ Assuming that the full technology cost gets passed along to 
the buyer as an increase in price, the technology cost thus measures 
the welfare loss to the buyer. Increasing fuel economy would have to 
lead to other changes in the vehicles that buyers find undesirable for 
there to be additional losses not included in the technology costs.
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    \365\ This approach describes the economic concept of 
compensating variation, a payment of money after a change that would 
make a consumer as well off after the change as before it. A related 
concept, equivalent variation, estimates the income change that 
would be an alternative to the change taking place. The difference 
between them is whether the consumer's point of reference is her 
welfare before the change (compensating variation) or after the 
change (equivalent variation). In practice, these two measures are 
typically very close together.
    \366\ Indeed, it is likely to be an overestimate of the loss to 
the consumer, because the consumer has choices other than buying the 
same vehicle with a higher price; she could choose a different 
vehicle, or decide not to buy a new vehicle. The consumer would 
choose one of those options only if the alternative involves less 
loss than paying the higher price. Thus, the increase in price that 
the consumer faces would be the upper bound of loss of consumer 
welfare, unless there are other changes to the vehicle due to the 
fuel economy improvements that make the vehicle less desirable to 
consumers.
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    The costs estimates include the costs of holding other vehicle 
attributes, such as performance, constant. The 2010 light-duty GHG/CAFE 
rule, discussed that if other vehicle attributes are not held constant, 
then the cost estimates do not capture the impacts of these 
changes.\367\ The light duty rule also discussed other potential issues 
that could affect the calculation of the welfare impacts of these types 
of changes, such as behavioral issues affecting the demand for 
technology investments, investment horizon uncertainty, and the rate at 
which truck owners trade off higher vehicle purchase price against 
future fuel savings. The agencies seek comments, including supporting 
data and quantitative analyses, if possible, of any additional impacts 
of the proposed standards on vehicle attributes and performance, and 
other potential aspects that could positively or negatively affect the 
welfare implications of this proposed rulemaking, not addressed in this 
analysis.
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    \367\ Environmental Protection Agency and Department of 
Transportation, ``Light-Duty Vehicle Greenhouse Gas Emissions 
Standards and Corporate Average Fuel Economy Standards; Final 
Rule,'' Federal Register 75(88) (May 7, 2010). See especially 
sections III.H.1 (pp. 25510-25513) and IV.G.6 (pp. 25651-25657).
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    The total monetized benefits (excluding fuel savings) under the 
program are projected to be $1.5 to $7.9 billion in 2030, depending on 
the value used for the social cost of carbon. These benefits are 
summarized below in Table VIII-25. The costs of the program in 2030 are 
estimated to be approximately $1.9 billion for new engine and truck 
technology less $19 billion in savings realized by trucking operations 
through fewer fuel expenditures (calculated using pre-tax fuel prices). 
These costs are summarized below in Table VIII-24. The present value of 
the total monetized benefits (excluding fuel savings) under the program 
are expected to range from $23 billion to $150 billion with a 3% 
discount rate; with a 7% discount rate, the total monetized benefits 
are expected to range from $15 billion to

[[Page 74303]]

$140 billion. These values, summarized in Table VIII-25, depend on the 
value used for the social cost of carbon. The present value of costs of 
the program for new engine and truck technology, in Table VIII-24, are 
expected to be $42 billion using a 3% discount rate, and $23 billion 
with a 7% discount rate, less fuel savings (calculated using pre-tax 
fuel prices) of $350 billion with a 3% discount rate, and $150 billion 
with a 7% discount rate. Total present net benefits (in Table VIII-26) 
are thus expected to range from $330 billion to $460 billion with a 3% 
discount rate, and $150 billion to $270 billion with a 7% discount 
rate.
    The estimates developed here are measured against a baseline fuel 
economy associated with MY 2010 vehicles. The extent to which fuel 
economy improvements may have occurred in the absence of the rules 
affect the net benefits associated with the rule. If trucks would have 
ended up installing technologies to achieve the fuel savings and 
reduced GHG emissions in the absence of this proposal, then both the 
costs and benefits of these fuel savings could be attributed to market 
forces, not the rules. At this time, the agencies do not have estimates 
of the extent of fuel-saving technologies that might have been adopted 
in the absence of this proposal. We seek comment on whether the 
agencies should use an alternative baseline based on data provided by 
commenters to estimate the degree to which the technologies discussed 
in this proposal would have been adopted in the absence of this 
proposal.
    EPA has undertaken an analysis of the economy-wide impacts of the 
proposed heavy-duty truck fuel efficiency and GHG standards as an 
exploratory exercise that EPA believes could provide additional 
insights into the potential impacts of the program.\368\ These results 
were not a factor regarding the appropriateness of the proposed 
standards. It is important to note that the results of this modeling 
exercise are dependent on the assumptions associated with how 
manufacturers would make fuel efficiency improvements and how trucking 
operations would respond to increases in higher vehicle costs and 
improved vehicle fuel efficiency as a result of the proposed program.
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    \368\ See Memorandum to Docket, ``Economy-Wide Impacts of 
Proposed Heavy-Duty Truck Greenhouse Gas Emissions and Fuel 
Efficiency Standards'', October 8, 2010. Docket EPA-HQ-OAR-2010-
0162.
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    Further information on these and other aspects of the economic 
impacts of our rules are summarized in the following sections and are 
presented in more detail in the draft RIA for this proposed rulemaking.

A. Conceptual Framework for Evaluating Impacts

    This regulation is motivated primarily by the goals of reducing 
emissions of greenhouse gases and promoting U.S. energy security by 
reducing consumption and imports of petroleum-based fuels. These 
motivations involve classic externalities, meaning that private 
decisions do not incorporate all of the costs associated with these 
problems; these costs are not borne completely by the households or 
businesses whose actions are responsible for them. In the absence of 
some mechanism to ``internalize'' these costs--that is, to transfer 
their burden to individuals or firms whose decisions impose them--
individuals and firms will consume more petroleum-based fuels than is 
socially optimal. Externalities are a classic motivation for government 
intervention in markets. These externalities, as well as effects due to 
changes in emissions of other pollutants and other impacts, are 
discussed in Sections VIII.H-VIII.J.
    In some cases, these classic externalities are by themselves enough 
to justify the costs of imposing fuel efficiency standards. For some 
discount rates and some projected social costs of carbon, however, the 
reductions in these external costs are less than the costs of new fuel 
saving technologies needed to meet the standards. (See Tables 9-18 and 
9-19 in the draft RIA.) Nevertheless, this regulation reduces trucking 
companies' fuel costs; according to our estimates, these savings in 
fuel costs are by themselves sufficient to pay for the technologies 
over periods of time considerably shorter than vehicles' expected 
lifetimes under the assumptions used for this analysis (e.g., AEO 2010 
projected fuel prices). If these estimates are correct, then the entire 
value of the reductions in external costs represents additional net 
benefits of the rule, beyond those resulting from the fact that the 
value of fuel savings exceeds the costs of technologies necessary to 
achieve them.
    It is often asserted that there are cost-effective fuel-saving 
technologies that truck companies are not taking advantage of. This is 
commonly known as the ``energy gap'' or ``energy paradox.'' Standard 
economic theory suggests that in normally functioning competitive 
markets, interactions between vehicle buyers and producers would lead 
producers to incorporate all cost-effective technology into the 
vehicles that they offer, without government intervention. Unlike in 
the light-duty vehicle market, the vast majority of vehicles in the 
medium- and heavy-duty truck market are purchased and operated by 
businesses with narrow profit margins, and for which fuel costs 
represent a substantial operating expense.
    Even in the presence of uncertainty and imperfect information--
conditions that hold to some degree in every market--we generally 
expect firms to attempt to minimize their costs in an effort to survive 
in a competitive marketplace, and therefore to make decisions that are 
in the best interest of the company and its owners and/or shareholders. 
In this case, the benefits of the rules would be due exclusively to 
reducing the economic costs of externalities resulting from fuel 
production and consumption. However, as discussed below in Section 
VIII.E, the agencies have estimated that the application of fuel-saving 
technologies in response to the proposed standards would, on average, 
yield private returns to truck owners of 140% to 420% (see Table VIII-
21 below). The agencies have also estimated that the application of 
these technologies would be significantly lower in the absence of the 
proposed standards (i.e., under the ``no action'' regulatory 
alternative), meaning that truck buyers and operators ignore 
opportunities to make investments in higher fuel economy that appear to 
offer significant cost savings.
    There are several possible explanations in the economics literature 
for why trucking companies do not adopt technologies that would be 
expected to increase their profits: there could be a classic market 
failure in the trucking industry--market power, externalities, or 
asymmetric or incomplete (i.e., missing market) information; there 
could be institutional or behavioral rigidities in the industry (union 
rules, standard operating procedures, statutory requirements, loss 
aversion, etc.), whereby participants collectively do not minimize 
costs; or the engineering estimates of fuel savings and costs for these 
technologies might overstate their benefits or understate their costs 
in real-world applications.
    To try to understand why trucking companies have not adopted these 
seemingly cost-effective fuel-saving technologies, the agencies have 
surveyed published literature about the energy paradox, and held 
discussions with numerous truck market participants. Below, we have 
listed five categories of possible explanations derived from these 
sources. Collectively, these five hypotheses may explain the apparent 
inconsistency between the

[[Page 74304]]

engineering analysis, which finds a number of cost-effective methods of 
improving fuel economy, and the observation that many of these 
technologies are not widely adopted.
    These hypotheses include imperfect information in the original and 
resale markets, split incentives, uncertainty about future fuel prices, 
and adjustment and transactions costs. As the discussion will indicate, 
some of these explanations suggest failures in the private market for 
fuel-saving technology in addition to the externalities caused by 
producing and consuming fuel that are the primary motivation for the 
rules. Other explanations suggest market-based behaviors that may imply 
additional costs of regulating truck fuel efficiency that are not 
accounted for in this analysis. Anecdotal evidence from various 
segments of the trucking industry suggests that many of these 
hypotheses may play a role in explaining the puzzle of why truck 
purchasers appear to under-invest in fuel economy, although different 
explanations may apply to different segments, or even different 
companies. The published literature does not appear to include 
empirical analysis or data related to this question.
    The agencies invite comment on these explanations, and on any data 
or information that could be used to investigate the role of any or all 
of these five hypotheses in explaining this energy paradox as it 
applies specifically to trucks. The agencies also request comment and 
information regarding any other hypotheses that could explain the 
appearance that cost-effective fuel-saving technologies have not been 
widely incorporated into trucks.
(1) Information Issues in the Original Sale Markets
    One potential hypothesis for why the trucking industry does not 
adopt what appear to be inexpensive fuel saving technologies is that 
there is inadequate or unreliable information available about the 
effectiveness of many fuel-saving technologies for new vehicles. As the 
NAS report notes, ``Reliable, peer-reviewed data on fuel saving 
performance is available only for a few technologies in a few 
applications. As a result, the committee had to rely on information 
from a wide range of sources, * * * including many results that have 
not been duplicated by other researchers or verified over a range of 
duty cycles.'' If reliable information on the effectiveness of many new 
technologies is absent, truck buyers will understandably be reluctant 
to spend additional money to purchase vehicles equipped with unproven 
technologies.
    This lack of information can manifest itself in multiple ways. For 
instance, the problem may arise purely because collecting reliable 
information on technologies is costly (also see Section VIII.A.5 on 
transaction costs). Moreover, information has aspects of a public good, 
in that no single firm has the incentive to do the costly 
experimentation to determine whether or not particular technologies are 
cost-effective, while all firms benefit from the knowledge that would 
be gained from that experimentation. Similarly, if multiple firms must 
conduct the same tests to get the same information, costs could be 
reduced by some form of coordination of information gathering.
    There are several possible reasons why trucking firms may 
experience difficulty gathering or interpreting information about fuel-
saving technologies. It may be difficult for truck drivers and fleet 
operators to separate the individual effects of various technologies 
and operating strategies from one another, particularly when they tend 
to be used in conjunction. It may also be difficult for truck operators 
to assess the applicability of even objective and reliable test results 
to their own specific vehicle configurations and operating practices; 
at the same time, the effects of specific technologies or operating 
practices may vary with geography, season of the year, or other 
factors. In highly competitive markets, any firm that conducts tests of 
fuel efficiency is unlikely to share results with other firms. If so, 
then cost-effective technological improvements may not be adopted 
because they cannot be reliably distinguished from inefficient 
technologies.
    To some extent, information about the effectiveness of some 
selected technologies does exist, and it suggests that some 
technologies appear to be very cost-effective in some situations. The 
SmartWay Transport Partnership is a complementary partnership between 
EPA and the freight goods industry (shippers, truck and rail carriers, 
and logistics companies) whose aim is to provide better information on 
fuel-efficient, low-carbon technologies and operational practices to 
help accelerate their deployment. SmartWay initially focused on 
evaluating and testing technologies for use in over-the-road class 8 
tractor-trailers, commonly operated by the large, national trucking 
fleets. For this reason, more information is available about the 
configuration and operation of these types of trucks. Many of the 
technologies that SmartWay selected for evaluation can also save fuel 
and reduce greenhouse gas emissions in other types of trucks and 
trucking operations. However, due to the wide diversity among other 
types of trucks and truck operations, and lack of precise information 
about the effectiveness of technologies in each one of these types of 
truck and trucking operations, it is difficult for the program to 
provide good information that is specific to each company. This makes 
it much more challenging to improve market confidence in fuel-saving 
technologies for these other truck types in the same way that SmartWay 
has done with its existing partners. SmartWay will continue to serve as 
a test bed for emerging technologies and as a conduit for technical 
information by developing and sharing information on other types of 
medium- and heavy-duty vehicles, helping to build market confidence in 
innovative financial, technical and operational solutions for medium- 
and heavy-duty vehicles across the freight goods industry, and 
promoting retrofit fuel-saving technologies within the existing legacy 
fleet. Information provision, such as the efforts of the SmartWay 
program, is a direct, non-regulatory approach to addressing the problem 
of the availability and reliability of results, as long as truck 
purchasers are able and willing to act on the information.
    While its effect on information is indirect, we expect the 
requirement for the use of new technologies included in this proposal 
will circumvent these information issues, resulting in their adoption, 
thus providing more readily available information about their benefits. 
The agencies appreciate, however, that the diversity of truck uses, 
driving situations, and driver behavior willl lead to variation in the 
fuel savings that individual trucks or fleets experience from using 
specific technologies.
(2) Information Issues in the Resale Market
    In addition to issues in the new vehicle market, a second 
hypothesis for why trucking companies may not adopt what appear to be 
cost-effective technologies to save fuel is that the resale market may 
not reward the addition of fuel-saving technology to vehicles 
adequately to ensure their original purchase by new truck buyers. This 
inadequate payback for users beyond the original owner may contribute 
to the short payback period that new purchasers appear to expect.\369\ 
The agencies seek data and information on the extent to which costs of 
fuel-

[[Page 74305]]

saving equipment can be recovered in the resale truck market.
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    \369\ See NAS 2010, Note 111, at p. 188.
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    Some of this unwillingness to pay for fuel-saving technology may be 
due to the extension of the information problems in the new vehicle 
market into resale markets. Buyers in the resale market have no more 
reason to trust information on fuel-saving technologies than buyers in 
the original market. Because actual fuel economy of trucks on the road 
depends on many factors, including geography and driving styles or 
habits, even objective sources such as logs of truck performance for 
used vehicles may not provide reliable information about the fuel 
economy that potential purchasers of used trucks will experience.
    A related possibility is that vehicles will be used for different 
purposes by their second owners than those for which they were 
originally designed. For instance, a vehicle originally purchased for 
long hauls might be used by its second owner instead for regional or 
intrastate trips, in which case some of the fuel-saving measures that 
proved effective in its original use may not be equally effective in 
these new uses. If information were more widely available and reliable, 
then purchasers in the resale market would seek vehicles with 
technologies that best suited their purposes, and buyers would be 
matched with sellers so that used vehicles would be used primarily for 
purposes in which their fuel-saving technologies were most valuable.
    It is also possible, though, that the fuel savings experienced by 
the secondary purchasers may not match those experienced by their 
original owners if the optimal secondary new use of the vehicle does 
not earn as many benefits from the technologies. In that case, the 
premium for fuel-saving technology in the secondary market should 
accurately reflect its value to potential buyers participating in that 
market, even if it is lower than its value in the original market, and 
the market has not failed. Because the information necessary to 
optimize use in the secondary market may not be readily available or 
reliable, however, buyers in the resale market may have less ability 
than purchasers of new vehicles to identify and gain the advantages of 
new fuel-saving technologies, and may thus be even less likely to pay a 
premium for them.
    For these reasons, purchasers' willingness to pay for fuel-economy 
technologies may be even lower in the resale market than in the 
original equipment market. Even when fuel-saving technologies will 
provide benefits in the resale markets, purchasers of used vehicles may 
not be willing to compensate their original owners fully for their 
remaining value. As a result, the purchasers of original equipment may 
expect the resale market to provide inadequate appropriate compensation 
for the new technologies, even when those technologies would reduce 
costs for the new buyers. This information issue may partially explain 
what appears to be the very short payback periods required for new 
technologies in the new vehicle market.
(3) Split Incentives in the Medium- and Heavy-Duty Truck Industry
    A third hypothesis explaining the energy paradox as applied to 
trucking involves split incentives. When markets work effectively, 
signals provided by transactions in one market are quickly transmitted 
to related markets and influence the decisions of buyers and sellers in 
those related markets. For instance, in a well-functioning market 
system, changes in the expected future price of fuel should be 
transmitted rapidly to those who purchase trucks, who will then 
reevaluate the amount of fuel-saving technology to purchase for new 
vehicles. If for some reason a truck purchaser will not be directly 
responsible for future fuel costs, or the individual who will be 
responsible for fuel costs does not decide which truck characteristics 
to purchase, then those price signals may not be transmitted 
effectively, and incentives can be described as ``split.''
    One place where such a split may occur is between the owners and 
operators of trucks. Because they are generally responsible for 
purchasing fuel, truck operators have strong incentives to economize on 
its use, and are thus likely to support the use of fuel-saving 
technology. However, the owners of trucks or trailers are often 
different from operators, and may be more concerned about their 
longevity or maintenance costs than about their fuel efficiency when 
purchasing vehicles. As a result, capital investments by truck owners 
may be channeled into equipment that improves vehicles' durability or 
reduces their maintenance costs, rather than into fuel-saving 
technology. If operators can choose freely among the trucks they drive, 
competition among truck owners to employ operators would encourage 
owners to invest in fuel-saving technology. However, if truck owners 
have more ability to choose among operators, then market signals for 
improved fuel savings that would normally be transmitted to truck 
owners may be muted.
    Anecdotal information about large truck fleets suggests that, even 
within a company, the office or department responsible for truck 
purchases is often different from that responsible for purchasing fuel. 
Therefore, the employees who purchase trucks may have strong incentives 
to lower their initial capital cost, but not equally strong incentives 
to lower operating costs.
    Single-wide tires, which save fuel and allow more payload (thus 
increasing revenue), offer another example of split incentives. They 
require a different driving style; those concerned about retaining 
drivers may resist their purchase, because drivers may not like the 
slightly different ``feel'' of wheel torque needed. Maintenance and 
repair staff may resist them because the tires may not be as available 
as they would like on the road, or they may need to change road service 
providers. Finally, those who resell the trucks may believe that the 
resale market will not value the tires. While financial pressures 
should provide incentives for greater coordination, especially when 
fuel costs are a large share of operating costs, it may be difficult 
institutionally to change budgeting procedures and to coordinate across 
offices. Thus, even within a company incentives for fuel savings may 
not be fully transmitted to those responsible for purchasing decisions.
    In addition, the NAS report notes that split incentives can arise 
between tractor and trailer operators.\370\ Trailers affect the fuel 
efficiency of shipping, but trailer owners do not face strong 
incentives to coordinate with truck owners. Although some trucking 
fleets own or lease their own trailers, a significant part of the 
trucking business is ``drop and hook'' service, in which trucking 
fleets pick up and drop off trailers and containers. These trailers and 
containers can belong to shippers, other trucking companies, leasing 
companies, or ocean-going vessel lines, in which cases their owners may 
not face strong incentives to economize on fuel consumption by tractor 
operators. Though tractor operators should, in principle, have some 
ability to arrange tractor-trailer combinations that provide increased 
fuel efficiency, the value of the resulting fuel savings may be small 
relative to the complexity and cost involved. EPA and NHTSA are not 
proposing to regulate trailers in this proposal.
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    \370\ See NAS 2010, Note 111, at p. 182.
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    By itself, information provision may be inadequate to address the 
potential underinvestment in fuel economy

[[Page 74306]]

resulting from such split incentives. In this setting, regulation may 
contribute to fuel savings that otherwise may be difficult to achieve.
    The agencies seek evidence and data on the extent to which split 
incentives affect purchasing choices in truck markets. For example, are 
trailer buyers that do not own their own tractors less likely to 
purchase aerodynamic trailers than those that purchase and drive both 
tractors and trailers?
(4) Uncertainty About Future Cost Savings
    Another hypothesis for the lack of adoption of seemingly fuel 
saving technologies may be uncertainty about future fuel prices or 
truck maintenance costs. When purchasers have less than perfect 
foresight about future operating expenses, they may implicitly discount 
future savings in those costs due to uncertainty about potential 
returns from investments that reduce future costs. In contrast, the 
immediate costs of the fuel-saving or maintenance-reducing technologies 
are certain and immediate, and thus not subject to discounting. In this 
situation, both the expected return on capital investments in higher 
fuel economy and potential variance about its expected rate may play a 
role in a firm's calculation of its payback period on such investments.
    In the context of energy efficiency investments for the home, 
Metcalf and Rosenthal (1995) and Metcalf and Hassett (1995) observe 
that households weigh known, up-front costs that are essentially 
irreversible against an unknown stream of future fuel savings.\371\ 
Uncertainty about the value of future energy savings may make risk-
averse households reluctant to invest in energy-saving technologies 
that appear to offer attractive economic returns. These authors find 
that it is possible to replicate the observed adoption rates for 
household energy efficiency improvements by incorporating the effect of 
uncertainty about the value of future energy savings into an empirical 
model. Notably, in this situation, requiring households to adopt 
technologies more quickly may make them worse off by imposing 
additional risk on them.
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    \371\ Metcalf, G., and D. Rosenthal (1995). ``The `New' View of 
Investment Decisions and Public Policy Analysis: An Application to 
Green Lights and Cold Refrigerators,'' Journal of Policy Analysis 
and Management 14: 517-531. Hassett and Metcalf (1995). ``Energy Tax 
Credits and Residential Conservation Investment: Evidence from Panel 
Data'' Journal of Public Economics 57 (1995): 201-217. Metcalf, G., 
and K. Hassett (1999). ``Measuring the Energy Savings from Home 
Improvement Investments: Evidence from Monthly Billing Data.'' The 
Review of Economics and Statistics 81(3): 516-528.
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    Greene et al. (2009) also find support for this explanation in the 
context of light-duty fuel economy decisions: a loss-averse consumer's 
expected net present value of increasing the fuel economy of a 
passenger car can be very close to zero, even if a risk-neutral 
expected value calculation shows that its buyer can expect significant 
net benefits from purchasing a more fuel-efficient car.\372\ These 
authors note that uncertainty regarding the future price of gasoline is 
a less important source of this result than is uncertainty about the 
lifetime, expected use, and reliability of the vehicle. Supporting this 
hypothesis is a finding by Dasgupta et al. (2007) that consumers are 
more likely to lease than buy a vehicle with higher maintenance costs 
because it provides them with the option to return it before those 
costs become too high.\373\ However, the agencies know of no studies 
that have estimated the impact of uncertainty on perceived future 
savings for medium- and heavy-duty vehicles.
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    \372\ Greene, D., J. German, and M. Delucchi (2009). ``Fuel 
Economy: The Case for Market Failure'' in Reducing Climate Impacts 
in the Transportation Sector, Sperling, D., and J. Cannon, eds. 
Springer Science.
    \373\ Dasgupta, S., S. Siddarth, and J. Silva-Risso (2007). ``To 
Lease or to Buy? A Structural Model of a Consumer's Vehicle and 
Contract Choice Decisions.'' Journal of Marketing Research 44: 490-
502.
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    Purchasers' uncertainty about future fuel prices implies that 
mandating improvements in fuel efficiency can reduce the expected 
utility associated with truck purchases. This is because adopting such 
regulation requires purchasers to assume a greater level of risk than 
they would in its absence, even if the future fuel savings predicted by 
a risk-neutral calculation actually materialize. Thus the mere 
existence of uncertainty about future savings in fuel costs does not by 
itself assure that regulations requiring improved fuel efficiency will 
necessarily provide economic benefits for truck purchasers and 
operators. On the other hand, because risk aversion reduces expected 
returns for businesses, competitive pressures can reduce risk aversion: 
risk-neutral companies can make higher average profits over time. Thus, 
significant risk aversion is unlikely to survive competitive pressures.
(5) Adjustment and Transactions Costs
    Another hypothesis is that transactions costs of changing to new 
technologies (how easily drivers will adapt to the changes, e.g.) may 
slow or prevent their adoption. Because of the diversity in the 
trucking industry, truck owners and fleets may like to see how a new 
technology works in the field, when applied to their specific 
operations, before they adopt it. If a conservative approach to new 
technologies leads truck buyers to adopt new technologies slowly, then 
successful new technologies are likely to be adopted over time without 
market intervention, but with potentially significant delays in 
achieving fuel saving, environment, and energy security benefits.
    In addition, there may be costs associated with training drivers to 
realize the potential fuel savings enabled by new technologies, or with 
accelerating fleet operators' scheduled fleet turnover and replacement 
to hasten their acquisition of vehicles equipped with new fuel-saving 
technologies. Here, again, there may be no market failure; requiring 
the widespread use of these technologies may impose adjustment and 
transactions costs not included in this analysis. As in the discussion 
of the role of risk, these adjustment and transactions costs are 
typically immediate and undiscounted, while their benefits are future 
and uncertain; risk or loss aversion may further discourage companies 
from adopting new technologies.
    To the extent that there may be transactions costs associated with 
the new technologies, then regulation gives all new truck purchasers a 
level playing field, because it will require all of them to adjust on 
approximately the same time schedule. If experience with the new 
technologies serves to reduce uncertainty and risk, the industry as a 
whole may become more accepting of new technologies. This could 
increase demand for future new technologies and induce additional 
benefits in the legacy fleet through complementary efforts such as 
SmartWay.
(6) Summary
    On the one hand, commercial vehicle operators are under competitive 
pressure to reduce operating costs, and thus their purchasers would be 
expected to pursue and rapidly adopt cost-effective fuel-saving 
technologies. On the other hand, the short payback period required by 
buyers of new trucks is a symptom that suggests some combination of 
uncertainty about future cost savings, transactions costs, and 
imperfectly functioning markets.