[Federal Register Volume 77, Number 3 (Thursday, January 5, 2012)]
[Notices]
[Pages 488-497]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-33842]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-9616-1]
Control of Emissions From New Highway Vehicles and Engines;
Approval of New Scheduled Maintenance for Selective Catalytic Reduction
Technologies
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of approval.
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SUMMARY: This notice announces that EPA has granted certain diesel
vehicle and engine manufacturers' requests for approval of emission-
related maintenance and scheduled maintenance intervals for
replenishment of reducing agent in connection with their use of
selective catalytic reduction (SCR) technologies. EPA's approval
pertains to the use of SCR with 2011 and later model year (MY) diesel-
fueled light-duty vehicles and light-duty trucks along with medium-duty
passenger vehicles and chassis-certified diesel vehicles up to 14,000
pounds gross vehicle weight (GVW) and 2012 and later MY heavy-duty
diesel engines.
FOR FURTHER INFORMATION CONTACT: David Dickinson, Compliance Division,
Office of Transportation and Air Quality, U.S. Environmental Protection
Agency, 1200 Pennsylvania Avenue (6405J), NW., Washington, DC 20460.
Telephone: (202) 343-9256. Fax: (202) 343-2800. Email:
[email protected].
SUPPLEMENTARY INFORMATION:
I. Background
EPA adopted new emission standards for light-duty vehicles on
February 10, 2000.\1\ At that time, EPA established an emission
standard of 0.07 grams per mile for each manufacturer's average full
life NOX emissions of its vehicles in each model year. For
heavy-duty vehicles and engines, EPA published a rule setting stringent
new requirements on January 18, 2001.\2\ Among other requirements, the
diesel engine NOX emission standard was set at 0.20 grams
per brake horsepower-hour (g/bhp-hr), to be phased-in between the 2007
and 2010 model years.
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\1\ 65 FR 6734 (February 10, 2000).
\2\ 66 FR 5002 (January 18, 2001).
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Diesel vehicle and engine manufacturers began planning to meet
those requirements by optimizing engine designs for low emissions and
adding high-efficiency aftertreatment systems. Manufacturers examined
the use of several different types of NOX reduction
technologies, including NOX absorbers, exhaust gas
recirculation, and selective catalytic reduction (SCR). SCR systems use
a nitrogen-containing reducing agent that usually contains urea and is
known as diesel exhaust fluid (DEF). The DEF is injected into the
exhaust gas upstream of a catalyst. For continued functioning of the
systems, the reducing agent needs to be replenished periodically by
refilling the DEF tank.
Maintenance performed on vehicles, engines, subsystems, or
components used to determine exhaust, evaporative, or refueling
emission deterioration factors is classified as either emission-related
or non-emission-related and scheduled or un-scheduled. Any emission-
related scheduled maintenance must be technologically necessary to
ensure in-use compliance with the emission standards. Manufacturers
must demonstrate to EPA that all of the emission-related maintenance to
be performed is technologically necessary and must be approved prior to
being performed or being included in maintenance instructions provided
to purchasers. 40 CFR 86.094-25(b)(3), 86.094-25(b)(4), 86.1834-
01(b)(3) and 86.1834-01(b)(4) establish minimum allowable maintenance
intervals for various emission-related technologies. EPA determined
that emission-related maintenance for the specified technologies at
intervals shorter than those listed in paragraphs (b)(3) and (b)(4) are
not technologically necessary, except as provided for in paragraphs
(b)(7). Paragraphs (b)(7) of those regulatory sections allows
manufacturers to request new scheduled maintenance and maintenance
intervals or a change to existing scheduled maintenance interval,
including an interval shorter than that prescribed in paragraphs (b)(3)
and (b)(4). For light-duty, medium-duty, and heavy-duty diesel-cycle
engines, emission-related maintenance for certain emission-related
components cannot occur before 100,000 miles of use.\3\ Thereafter,
emission-related maintenance cannot again occur before 100,000 mile
intervals for light heavy-duty engines, or before 150,000 mile
intervals for medium and heavy heavy-duty engines.\4\
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\3\ 40 CFR 86.1834-01(b)(4)(ii) and 40 CFR 86.004-25(b)(4)(iii).
\4\ Id.
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Pursuant to 40 CFR 86.1834-01(b)(7), a manufacturer must submit a
request to EPA for approval of any new scheduled maintenance that it
wishes to perform during durability determination and recommend to
purchasers. New scheduled maintenance is maintenance that did not exist
prior to the 1980 model year (such as DEF refills), including that
which is the direct result of the implementation of new technology not
found in production prior to the 1980 model year (such as SCR
technology). In their approval requests to EPA, manufacturers are
required to submit a variety of information, including a recommendation
as to the maintenance category (i.e., emission-related or non-emission-
related, and critical or non-critical). If the suggested maintenance is
emission-related, manufacturers must indicate the maximum feasible
maintenance interval. Manufacturers must also provide detailed
evidence, data, or other substantiation supporting the need for the new
scheduled maintenance, the categorization of such maintenance, and the
suggested interval, if the maintenance is emission-related.
If EPA approves a request for new scheduled maintenance, the Agency
then designates that maintenance as emission-related or non-emission-
related. For emission-related maintenance, EPA will further designate
that maintenance as critical or non-critical. A designation of critical
maintenance will be made if the component receiving the maintenance
meets the regulatory definition of critical emission-related component
in 40 CFR 86.1834-01(b)(6). Critical emission-related components
include catalytic converters. 40 CFR 86.1834-01(b)(6) requires that
critical emission-related maintenance must have a reasonable likelihood
of being performed in use, as shown by the manufacturer.\5\ Examples of
[[Page 489]]
demonstrations that maintenance will have a reasonable likelihood of
being performed in use include: Data establishing that a vehicle's
engine performance will deteriorate to an unacceptable point due to
poor emissions performance, survey data demonstrating an eighty percent
confidence level that maintenance is in fact performed in use, and
installation of a clearly displayed signal system to alert drivers that
maintenance is required. When approving a new scheduled maintenance
request, EPA also establishes a technologically necessary maintenance
interval, based on the evidence submitted by industry and any other
information available to the Agency.
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\5\ 40 CFR 86.094(b)(6)(ii) and 86.1834-01(b)(6)(ii). Both
sections present the following conditions as acceptable of having a
reasonable likelihood that the maintenance item will be performed
in-use:
(A) Data are presented which establish for the Administrator a
connection between emissions and vehicle performance such that as
emissions increase due to lack of maintenance, vehicle performance
will simultaneously deteriorate to a point unacceptable for typical
driving.
(B) Survey data are submitted which adequately demonstrate to
the Administrator that, at an 80 percent confidence level, 80
percent of such engines already have this critical maintenance item
performed in-use at the recommended interval(s)
(C) A clearly displayed visible signal system approved by the
Administrator is installed to alert the vehicle driver that
maintenance is due. A signal bearing the message ``maintenance
needed'' or ``check engine,'', or a similar message approved by the
Administrator, shall be actuated at the appropriate mileage point or
by component failure. This signal must be continuous while the
engine is in operation and not be easily eliminated without
performance of the required maintenance. Resetting the signal shall
be a required step in the maintenance operation. The method for
resetting the signal system shall be approved by the Administrator.
(D) A manufacturer may desire to demonstrate through a survey
that a critical maintenance item is likely to be performed without a
visible signal on a maintenance item for which there is no prior in-
use experience without the signal. To that end, the manufacturer may
in a given model year market up to 200 randomly selected vehicles
per critical emission-related maintenance item without such visible
signals, and monitor the performance of the critical maintenance
item by the owners to show compliance with paragraph (b)(6)(ii)(B)
of this section. This option is restricted to two consecutive model
years and may not be repeated until any previous survey has been
completed. If the critical maintenance involves more than one engine
family, the sample will be sales weighted to ensure that it is
representative of all the families in question.
(E) The manufacturer provides the maintenance free of charge,
and clearly informs the customer that the maintenance is free in the
instructions provided under Sec. 86.087-38.
(F) Any other method which the Administrator approves as
establishing a reasonable likelihood that the critical maintenance
will be performed in-use.
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In 2007, EPA issued guidance indicating how the above-described
regulatory requirements for allowable maintenance could impact EPA
certification decisions regarding implementation of SCR technologies
for light-duty and heavy-duty diesel vehicles and engines.\6\ That
guidance announced that EPA would consider service operations performed
on SCR systems to be critical emission-related scheduled maintenance.
We stated our belief that because catalysts are listed in the (b)(3)
and (b)(4) provisions as critical emission-related components, and lack
of replenishing agent renders SCR catalysts inoperative, SCR system
maintenance would meet the definition of critical emission-related
maintenance. Therefore, allowable maintenance requirements would apply
to SCR systems, including SCR catalysts, reducing agent, reducing agent
storage tanks, dosing valves, and all lines and hoses. Additionally,
because manufacturers indicated that packaging constraints would
prevent them from being able to equip their vehicles with reducing
agent storage tanks of sufficient size to allow reducing agent
replenishment to comply with the general maintenance intervals of
100,000 or 150,000 miles, EPA clarified that manufacturers would likely
need to request a change to the scheduled maintenance interval pursuant
to the (b)(7) provision.
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\6\ U.S. Environmental Protection Agency, CISD 07-07, ``Dear
Manufacturer Letter Regarding Certification Procedure for Light-Duty
and Heavy-Duty Diesel Vehicles and Heavy-Duty Diesel Engines Using
Selective Catalytic Reduction (SCR) Technologies,'' March 27, 2007,
available at: http://iaspub.epa.gov/otaqpub/display_file.jsp?docid=16677&flag=1.
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In that same 2007 guidance, EPA also stated that an SCR system
utilizing a reducing agent that needs to be periodically replenished
could be an adjustable parameter as set forth in 40 CFR 86.094-22(e)(1)
and 86.1833-01(a)(1). Those regulatory provisions establish the
requirements for determining the physically adjustable ranges of
parameters, and EPA's 2007 guidance addressed its determination under
the regulations that operation without DEF is within the scope of such
ranges. EPA's 2007 guidance also provided industry-wide notice that SCR
system designs and information submitted by manufacturers during
certification could be used to provide EPA with assurance that DEF
levels will remain at proper ranges during the operation of their
vehicles and engines while in use.\7\
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\7\ EPA issued guidance on December 30, 2009. U.S. Environmental
Protection Agency, Dear Manufacturer Letter regarding ``Revised
Guidance for Certification of Heavy-Duty Diesel Engines Using
Selective Catalyst Reduction (SCR)Technologies,'' December 30, 2009,
reference number CISD-09-04 (HDDE), available at http://iaspub.epa.gov/otaqpub/display_file.jsp?docid=20532&flag=1.
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II. Previous Model Year Approval of New Scheduled Maintenance for SCR
Systems
In 2009, EPA approved manufacturer-specific and industry-wide new
scheduled maintenance interval requests for diesel-cycle motor vehicles
and motor vehicle engines equipped with SCR systems.\8\ At that time,
EPA stated that:
\8\ 74 FR 57672 (November 9, 2009).
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* * * SCR systems are a new type of technology designed to meet
the newest emission standards and the DEF refill intervals represent
a new type of scheduled maintenance; therefore, EPA believes that
manufacturers may request from EPA the ability to perform the new
scheduled maintenance of DEF refills. Requests from manufacturers
for new scheduled maintenance intervals must include: (1) Detailed
evidence supporting the need for the maintenance requested and (2)
supporting data or other substantiation for the recommended
maintenance category and for the interval suggested for the emission
maintenance. Any emission-related maintenance must be
technologically necessary to assure in-use compliance with the
emission standards since minimum service intervals are established
in part to ensure that the control of emissions is not compromised
by a manufacturer's overly frequent scheduling of emission-related
maintenance.
Upon review of industry-wide and manufacturer-specific evidence and
supporting data, EPA approved new scheduled maintenance intervals for
DEF equal to the scheduled oil change interval for light-duty vehicles
and trucks for the 2009 and 2010 model years. For heavy-duty vehicles
and engines through the 2011 model year, EPA approved new scheduled
maintenance intervals for DEF tanks based on ratios to a given
vehicle's fuel capacity. Vocational heavy-duty vehicles (e.g., dump
trucks, concrete mixers, refuse trucks, and other centrally-fueled
vehicles) were permitted a DEF tank maintenance interval no less than
the vehicle's fuel capacity (i.e., a 1:1 ratio of DEF refill to fuel
refill). For other heavy-duty vehicles, a longer interval was approved
depending upon whether the vehicle was equipped with a DEF level
indicator that would be constantly viewable by the operator. For those
heavy-duty vehicles with a DEF level indicator, EPA approved a DEF tank
refill interval no less than twice the range of the vehicle's fuel
capacity (i.e., a 2:1 ratio). For those heavy-duty vehicles without a
DEF level indicator, EPA approved a DEF tank refill interval no less
than three times the range of the vehicle's fuel capacity (i.e., a 3:1
ratio).
When evaluating the evidence, data, and justifications presented by
manufacturers to support their requested intervals, EPA identified as
significant the impact a larger sized DEF tank would have on vehicle
design and vehicle weight. To merely accommodate the inclusion of a DEF
tank into vehicle design, heavy-duty vehicle manufacturers had to
redesign their configurations by taking such measures as reducing the
number of batteries, designing space-saver configurations,
[[Page 490]]
lengthening frame rails, moving compressed air tanks inside the frame
rails, and redesigning fuel tank configurations. Light-duty car and
truck manufacturers had similar vehicle design issues related to their
inherently space constrained vehicles: they had to choose whether to
reduce interior vehicle space or find a place to accommodate a DEF tank
in the engine compartment of vehicle's undercarriage. Aside from
vehicle design issues, the addition of a large DEF tank onto any given
vehicle represents a significant addition of weight to the vehicle. The
addition of a significant amount of weight to a given vehicle, in turn,
presents its own concerns: added vehicle weight more quickly
deteriorates engine performance, and added vehicle weight decreases
fuel economy. With those considerations in mind, EPA announced its
approval of the requested maintenance intervals:
After reviewing this data and information, EPA believes that
longer refill intervals than those noted above would require larger
and heavier DEF tanks, and the design and engineering work performed
by manufacturers thus far indicate that the recommended DEF refill
intervals noted above approximate the maximum feasible maintenance
intervals associated with reasonable DEF tank sizes. The maintenance
intervals recommended ensure that the functions and operational
efficiency of such vehicles are not overly compromised. Based on
this information we believe the intervals noted above are
warranted.\9\
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\9\ 74 FR 57671, 57674 (November 9, 2009).
EPA's 2009 approval also noted that, ``while not a specific
criterion under paragraph (b)(7) of the regulations, because DEF refill
maintenance is considered `critical emission-related maintenance,'
paragraph (b)(6) requires that there be a reasonable likelihood that
the DEF maintenance refill will be performed in use.'' \10\ EPA then
noted the number of means available to make such a showing, including a
clearly displayed visible signal system or the presentation of
supporting data.
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\10\ See 40 CFR 86.1834-01(b)(6)(ii) and 86.094-25(b)(6)(ii).
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III. Current Requests for New Scheduled Maintenance for SCR Systems
A. Light-Duty Requests
1. Alliance of Automobile Manufacturers Request
EPA has received information from the Alliance of Automobile
Manufacturers (the ``Alliance''), that requested re-approval of new
scheduled maintenance for DEF refilling at service intervals (i.e., oil
change intervals) for light-duty vehicles and light-duty trucks (and
heavy-duty engines that are chassis-certified for NOX)
equipped with SCR systems.\11\ The Alliance presented several reasons
why the SCR maintenance interval should be equivalent to the service
interval, including: ``vehicles will be designed and equipped to ensure
vehicle compliance with emission standards; DEF will be readily
available and accessible to drivers; maintenance is likely to be
performed; there are engineering constraints on packaging a large DEF
tank on light duty vehicles; and there is a significant penalty on fuel
economy and performance associated with carrying both a larger DEF tank
and the weight of a large amount of DEF.''
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\11\ The Alliance represents BMW Group, Chrysler LLC, Ford Motor
Company, General Motors, Jaguar Land Rover, Mazda, Mercedes-Benz,
Mitsubishi Motors, Porsche, Toyota, and Volkswagen. EPA also
received similar information from Mahindra.
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With regard to the engineering constraints associated with
packaging a large quantity of DEF on light duty vehicles, the Alliance
notes that it is impractical to install a DEF tank of sufficient size
to achieve a 100,000 mile scheduled maintenance interval. ``Light duty
vehicles are constrained in the amount of space that can be dedicated
to a DEF tank. In addition to the DEF tank, SCR vehicles must package
an SCR catalyst, SCR mixer and DEF dosing and heating mechanisms.'' The
Alliance cites an example of a current production vehicle that provides
a 6.1 gallon DEF tank to achieve a 10,000 mile change interval ratio
tied to the oil change interval. To accommodate a 100,000 mile
maintenance requirement would require 60 gallons of DEF and would take
approximately 8 cubic feet of space--and would also be almost
equivalent to installing 4 extra fuel tanks. ``To reduce the existing
usable volume to such an extent would result in an uncompetitive
vehicle in terms of usable passenger or cargo volume.''
With regard to the Alliance's concerns regarding the potential for
a significant penalty on fuel economy and performance associated with
carrying both a larger DEF tank and the weight of a large amount of
DEF, they note the simple impracticability for light duty vehicles to
carry the weight of a DEF tank sufficient in size to achieve a 100,000
mile maintenance interval. Noting that such a tank could weigh as much
as 540 lbs it could affect fuel economy almost as much as 10% on a 3800
lb curb weight vehicle. The Alliance also notes similar handling
performance (acceleration, braking, and turning) along with passenger
space, cargo carrying and/or towing capacity.
2. Ford Request
EPA has received information from Ford (regarding its chassis-
certified vehicles) that is similar to the concerns raised by the
Alliance. In addition, Ford notes that by attempting to go to a longer
service interval, for example a 16-20 gallon DEF tank to meet a two oil
change interval, would not be feasible with the space limitations and
performance requirements that are necessary for typical medium-duty
vehicle (chassis-certified) design. In addition to the market concerns
associated with a loss in fuel capacity, cargo or truck bed space due
to a larger DEF tank not being acceptable to its customers, Ford also
notes the ``hard-point'' packaging issues with attempting to place a
large DEF tank in the engine compartment or in the vehicles
undercarriage.\12\
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\12\ Ford notes the undercarriage is already fully utilized with
the engine, exhaust system, catalytic converters, mufflers, fuel
tank, etc severely limiting any available space for a DEF tank. Ford
also notes that DEF tanks represent a significant weight challenge
which affects performance and fuel efficiency. To increase a DEF
tank for every 2 oil change interval would increase a tank weight by
72 lbs as one example.
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3. Isuzu Request
EPA also received information from Isuzu for its medium-duty
vehicle (chassis-certified vehicles with GVW of 8,501 to 10,000 pounds)
engine families. Isuzu requested a maintenance interval based on the
rate of DEF consumption. Isuzu presented that the DEF consumption rate
of 2% the rate of diesel fuel consumption renders it ``impossible'' to
equip a vehicle with a DEF tank large enough to operate for the full
120,000 mile maintenance interval without DEF. Isuzu requested its
interval based on reasons of technological necessity, including
maintenance is likely to be performed on schedule, there is limited
space available on vehicles for a large DEF tank, the physical
properties of DEF present limitations, and DEF is publicly and readily
available to drivers.
B. Heavy-Duty Requests
1. Engine Manufacturers Association Request
The Engine Manufacturers Association (``EMA'') renewed its previous
request for maintenance intervals for DEF refill for heavy-duty on-
highway diesel fueled engines and vehicles.\13\ EMA presents that the
[[Page 491]]
determinations of technological necessity that EPA made in 2009 still
apply today for DEF refill intervals.\14\ Specifically, EMA believes
that ``while the SCR-related urea infrastructure has continued to
develop, the space and weight constraints that are inherent to the
design and operation of [heavy-duty on-highway] vehicles, and the
underlying DEF consumption rate, have not changed. As a result, the
need and justification for the previously-approved reduced DEF
maintenance intervals also have not changed.'' EMA requests that EPA's
previously approved new scheduled maintenance intervals for DEF be
extended for the 2012 and later model years.\15\
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\13\ EMA members include AGCO Corporation, American Honda Motor
Company, Inc., Briggs & Stratton Corporation, Caterpillar Inc.,
Chrysler Group LLC, Cummins Inc., Daimler Trucks North America LLC,
Deere & Company, DEUTZ Corporation, Dresser Waukesha, Fiat
Powertrain Technologies S.p.A., Ford Motor Company, Hino Motors,
Ltd., Isuzu Manufacturing Services of America, Inc., Kohler Company,
Komatsu Ltd., Kubota Engine America Corporation, Navistar, Inc.,
Onan--Cummins Power Generation, PACCAR Inc., Scania CV AB, Tognum
America, Inc., Volkswagen of America, Inc., Volvo Powertrain
Corporation, W[auml]rtsil[auml] North America, Inc., Yamaha Motor
Corporation, and Yanmar America Corporation.
\14\ EMA cites from EPA's 2009 FR Notice: ``EPA believes that in
light of the existing tight space constraints and the overall desire
to maximize cargo-carrying capacity, minimize emissions and meet
consumer operation demands, and the built-in DEF tank size buffer to
insure DEF refills, that the DEF tank sizes associated with the 2:1
refill and 3:1 intervals are technologically necessary. EPA believes
that requiring tank sizes above these ratios will cause increases in
space constraints and weight that would not be appropriate for these
[HDOH] vehicles. * * * After reviewing this data and information,
EPA believes that longer refill intervals than those noted above
would require larger and heavier DEF tanks. And the design and
engineering work performed by manufacturers thus far indicate that
the recommended DEF refill intervals noted above approximate the
maximum feasible maintenance interval associated with reasonable DEF
tank sizes. The maintenance intervals recommended ensure that the
functions and operational efficiency of such vehicles are not overly
compromised. Based on this information we believe the intervals
noted above are warranted.'' See 74 FR at 57674.
\15\ EMA expressly states that one of its members--Navistar,
Inc.--does not support EMA's request.
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2. Volvo Request
By letter dated April 28, 2011, Volvo Powertrain North America and
Volvo Powertrain Japan (collectively, ``Volvo'') submitted a request
that EPA extend its previous approval of alternative scheduled
maintenance intervals for DEF tanks used in SCR systems. Volvo believes
that the intervals EPA previously approved remain technologically
necessary, ``as nothing about the design, constraints or functionality
of Volvo vehicles and engines has changed so as to permit the use of
larger tanks.'' Volvo further states that ``The inherent nature of
vehicle space and weight constraints makes significantly larger DEF
tanks infeasible on a practical basis. That said, larger DEF tanks also
are not necessary in light of systems Volvo has developed to ensure
that vehicle operators refill DEF tanks.'' Volvo states that to ensure
efficient and practical operation its trucks are designed in such a way
that they necessarily have space and weight constraints. Thus, there
are inherent limits on the size of add-on components, such as DEF
tanks, that can be installed on the vehicles and such limits are
unavoidable. In this context Volvo states that its trucks are designed
to operate using DEF at all times and that the size of the DEF tanks,
like the vehicle's fuel tank, dictates the vehicle's range of
operation. Volvo maintains that the 2:1 ratio remains technologically
necessary for model year 2012 engines and vehicles as nothing about the
design, constraints or functionality of Volvo vehicles and engines has
changed (since the 2009 approval) so as to permit the use of larger
tanks. Volvo also presents that it has implemented controls to assure
that there is ``more than a `reasonable likelihood' that the
recommended DEF refill intervals will be complied with in-use. Volvo
asserts that it has equipped its SCR-based systems with visible warning
systems and driver inducements such that vehicle performance will
deteriorate to an unacceptable point, in order to compel vehicle
operators to refill the DEF tank. Volvo initially developed these
strategies in consultation with EPA staff in order to ensure its
engines met EPA certification requirements, and has since improved its
strategies for current and future model year engines. In its request,
Volvo further describes the specific steps it has taken to design its
SCR systems to protect against operation of its vehicles without DEF
and to prevent SCR system tampering. In addition, Volvo seeks the
flexibility to utilize a 1:1 ratio in light of its 40% power reduction
(see further clarification below in the SCR Engine Manufacturers
request submitted after the Volvo request--EPA assumes this is the
flexibility that Volvo is seeking).
3. SCR Engine Manufacturers Request
EPA has also received requests for scheduled maintenance intervals
for 2012 and later model years from a group of SCR engine manufacturers
(collectively the ``SCR Engine Manufacturers'' \16\) that specifically
ask for EPA to approve the use of a 1:1 DEF to fuel ratio for vehicles
with a DEF level indicator, in addition to vocational vehicles. The SCR
Engine Manufacturers state that such approval is necessary and
appropriate to reflect current and anticipated changes in vehicle
designs, significant changes in inducement strategies, and the
increased availability of DEF since EPA's last approval in 2009.
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\16\ This group includes Chrysler Group, LLC, Cummins Inc.,
Daimler Trucks North America LLC, Detroit Diesel Corporation, Ford
Motor Company, Mack Trucks Inc., PACCAR Inc., UD Trucks Corporation,
and Volvo Group North America.
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The SCR Engine Manufacturers note that much of the information
required in a (b)(7) petition was confirmed by EPA in its 2009 notice
and thus needs no further elaboration. EPA has already concluded that
replenishment of DEF is ``technologically necessary'' critical
emission-related maintenance, and that the 1:1, 2:1, and 3:1 ratios
were ``maximum feasible'' maintenance intervals based on information
available in 2009. There has been no change in the need for DEF
replenishment or designation of the category of maintenance since 2009.
The SCR Engine Manufacturers new petition for a 1:1 DEF interval
reflects what is believed to be the ``maximum feasible interval'' based
on reasonable tank sizes, given the latest information regarding SCR
systems and DEF availability.
Included in the SCR Engine Manufacturers' petition is their
position regarding the threshold criteria that EPA should follow for
setting a ``technologically necessary maintenance interval.'' They
claim that the general maintenance regulations, including the
introductory paragraph of (b)(2) which helps frame the established
intervals in (b)(3) and (b)(4), provides guidance on what
``technologically necessary'' means when it states that any emission-
related maintenance ``must be technologically necessary to assure in-
use compliance with the emission standards.'' Thus EPA must first
determine whether an interval shorter than the regulatory default is
necessary in order to assure in-use compliance. They note that in the
2009 notice EPA specifically addressed the unique nature of liquid DEF
replenishment and the need to strike a reasonable balance between
conflicting design goals.
Thus, the SCR Engine Manufacturers maintain that the words
``technologically necessary'' are used in two contexts. First, as noted
above, (b)(2) requires all maintenance that meets the definition of
``emission-related maintenance'' ``must be technologically necessary to
assure in-use compliance with the emission standards.'' Consistent with
this provision is (b)(7)(ii) which requires that any alternative
interval set by EPA be ``a technologically necessary maintenance
interval'' (emphasis added). Thus the term ``technologically
necessary'' merely describes the
[[Page 492]]
category of maintenance that is allowable but not what the specific
interval must be. Subsequently, the SCR Engine Manufacturers note that
once EPA makes this threshold determination (as required in (b)(7))
then the Agency, with a level of discretion, examines the information
submitted by the petitioner. Such information includes the petitioner's
position on what is the ``maximum feasible maintenance'' including any
supporting data or other substantiation for the interval suggested.
Rather than looking at the ``maximum level'' that is technologically
feasible, the term ``feasible'' requires EPA to look at the overall
practicality and reasonableness of a particular proposed interval. The
maximum feasible interval is used as a point of reference for EPA to
evaluate the reasonableness of the manufacturers' recommended interval.
According to the SCR Engine Manufacturers, ``The maximum possible
interval for DEF replenishment is established in each case by the total
load capacity of the vehicle in question, the space available for a
given DEF tank size, the fuel efficiency and greenhouse gas impact of
various DEF dosing rates, the desired operating range of the vehicle
between fuel and DEF refills, and the impact of extra weight on vehicle
performance, safety, and compliance with U.S. Department of
Transportation regulatory requirements. DEF tank size must also be
balanced against the need to carry cargo, or to enable the vehicle to
meet the purpose for which it was built, to determine what is feasible
in the most economical way possible while achieving compliance.''
The SCR Engine Manufacturers suggest that as EPA performs its case-
by-case analysis, the likelihood of the maintenance being performed in-
use is the most important factor in establishing the precise
maintenance interval. EPA explained that ``minimum service intervals
are established in part to ensure that the control of emissions is not
compromised by a manufacturer's overly frequent scheduling of emission-
related maintenance.'' \17\ They also state that EPA explained in its
2009 notice that while the likelihood of maintenance being performed
in-use was a specific criteria under (b)(6), it was also a factor that
was ``important to note'' with regard to EPA's (b)(7) findings.
Further, EPA then concluded that it was reasonable to base the DEF
refilling event on diesel refueling intervals due to DEF infrastructure
developed at diesel refueling stations.
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\17\ EPA made this statement in its 2009 Notice, see 74 FR at
57673.
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EPA has also received information from the SCR Engine Manufacturers
indicating that EPA should set the minimum required DEF refill interval
at an interval equal to the vehicle's fuel capacity (i.e., a 1:1 ratio)
for all heavy duty engines.\18\ They claim that this shorter
maintenance interval is ``necessary and appropriate to reflect current
and anticipated changes in vehicle designs, significant changes in
inducement strategies, and the increased availability of DEF.'' They
note that certification practices of the EPA regarding inducement
practices for SCR-equipped engines make it ``essentially impossible for
an SCR vehicle to operate without regular DEF replenishment.'' They
state that the severity of inducements related to DEF levels (e.g.
severe reduction in engine power and/or vehicle speed) is
``extraordinary and must be taken into account'' when EPA is
determining appropriate maintenance intervals. They state that ``in
light of these severe inducements, it is reasonable to expect that a
driver with a 1:1 tank ratio will operate under a firm discipline that
the DEF tank must be refilled every time the fuel tanks are filled, as
opposed to a driver with a 2:1 or greater tank ratio who may become
accustomed to filling the DEF tank only when necessary, and is
therefore more likely to rely on gauge levels, warnings, and
inducements to trigger refills.''
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\18\ Letters dated August 18, 2011 and September 27, 2011 to
Karl Simon, EPA, Director, Compliance and Innovative Strategies
Division from R. Latane Montague, Hogan Lovells.
---------------------------------------------------------------------------
The SCR Engine Manufacturers also state that EPA's promulgation of
new standards regulating greenhouse gases increase the size and weight
restraints associated with DEF tank size.
EPA has announced new [greenhouse gas] standards for HDOH
trucks, and manufacturers have moved to voluntarily increase the
fuel efficiency of their vehicles in advance of the effective dates
of those regulations. Within these regulations, EPA recognizes the
impact of weight savings on fuel efficiency and GHG emissions. In
addition, manufacturers have developed innovative new DEF dosing
strategies to reduce CO2 emissions. These new strategies may involve
increasing the DEF dosing rate. Increasing the DEF dosing rate also
makes it more and more difficult to satisfy a 2:1 tank size ratio
without increasing the size of the DEF tank above the size EPA
previously considered the maximum reasonable size. For this reason,
if the application of the 1:1 tank ratio is not expanded, EPA will
effectively be mandating larger DEF tanks, with their accompanying
weight increase, in order to accommodate technology advancements
developed to reduce CO2 emissions--tanks that are larger than the
tanks EPA determined to be the maximum reasonably required in 2009.
In addition, this could inadvertently cause manufacturers to
restrict application of the most fuel efficient engines to vehicles
that have reduced range between fuel and DEF refills, such that they
will be unattractive to the line-haul fleets that consume the most
fuel.
The commenters elaborated that:
To meet the next round of GHG reduction requirements, some
manufacturers expect to increase DEF dosing by as much as 100% over
current levels. These increased levels of dosing will require a
corresponding increase in DEF tank capacity and size to meet the
existing 2:1 tank ratio requirements. For example, increasing DEF
dosing by 40% on average would require an increase in DEF tank size
of approximately 40% (depending on how much extra capacity was
included in the tanks used in previous model years). The shape, size
and location of DEF tanks on a truck frame are constrained by a
number of factors including: the need to place the tank below the
filler-neck; the need for clearance from other components such as
fuel tanks, battery boxes, air tanks, diesel particulate filters,
and the drive axle and wheels; the need for gravity feed; body
installation requirements; clear-back-of-cab requirements; weight
distribution requirements; bridge formula and related axle placement
issues; and fuel capacity/driving range demands.
They state that another consequence of the greenhouse gas
regulations is more attention to improved aerodynamics and weight
reduction, which are harmed by the need for a 2:1 DEF tank size
requirement. They claim that EPA should allow manufacturers to use all
available options to increase fuel economy and meet greenhouse gas
standards. They state the possible harm of allowing shorter maintenance
intervals is minimal, given the severe negative inducements associated
with failure to replenish the DEF tank.
4. Navistar's Opposition to Renewed Requests
EPA has received information from Navistar expressing its
opposition to any extension of EPA's previously approved DEF refill
intervals. Navistar maintains that the touchstone of allowable
maintenance is whether it is reasonably likely that the maintenance
will be performed. To this point, it states that EPA's own
certification guidance ensures that maintenance will not occur, or at
least not for lengthy periods of time. It also states that EPA's
inducements to cause drivers to replenish DEF do not work and, and by
definition, ensure that maintenance will not occur.\19\ Separately,
Navistar
[[Page 493]]
contends that the previously approved intervals are not
``technologically necessary'' under EPA's regulations. The purpose of
EPA's maintenance regulations is to reduce the amount of driver
attention emissions systems require in order to ensure that certified
engines comply with emission standards on the road. Navistar claims
that the Clean Air Act (CAA) and EPA's regulations require that SCR
engine manufacturers make efforts to improve the durability of their
driver-dependent emission control systems after MY 2009. Navistar
points to EPA's statement from the 2009 approval (``expectation that
SCR-related technologies and the urea infrastructure will continue to
develop and mature.''), as evidence that EPA must require continuous
improvement.\20\ Navistar states that ``other SCR technology is now
available that offers exponentially longer maintenance ranges, weighs
less and conserves fuel more.'' Navistar maintains that EPA's approved
maintenance for liquid, urea-based SCR is not about ``technological
necessity''. SCR engine manufacturers can easily quadruple the refill
interval with little or no effort. They also suggest that EPA cannot
legally accept SCR engine manufacturers' lack of effort and extend the
same illegal DEF-replacement maintenance intervals for future model
years. ``Because other SCR technology is proven to be available with a
maintenance interval in the range of 35,000 to 45,000 miles, EPA's own
allowable maintenance regulations require that liquid, urea-based SCR
meet that same benchmark.''
---------------------------------------------------------------------------
\19\ Navistar throughout its comments returns to its theme that
EPA's certification scheme allows DEF refills to be deferred for
lengthy periods of time. As such, Navistar maintains that EPA has
illegally amended its allowable maintenance regulations to eliminate
the requirement that maintenance be shown as likely to occur.
Similarly, Navistar points to EPA's 2001 rulemaking and maintains
that EPA ``concluded its maintenance inducements do not create a
reasonable likelihood that the maintenance will be performed. (See
2011 Rule at 5053 (finding no ``adequate safeguards in place to
ensure the [DEF] is used throughout the life of the vehicle.'')
\20\ Navistar maintains that SCR engine makers could have
substantially increased the 2009-2011 DEF replacement intervals by
doubling the size of the DEF tank and decreasing urea consumption by
half.
---------------------------------------------------------------------------
Navistar also chooses to contrast liquid, urea-based SCR systems
with other emission control technologies to suggest that the
maintenance interval tied with DEF refills is unnecessarily short They
note EPA's approval of new scheduled maintenance for exhaust
recirculation valves at 67,500 miles.\21\ Navistar states that EPA's
basis for defining ``technologically necessary'' has always been ``the
longest interval that any manufacturer recommend(s).'' \22\ Lastly,
Navistar notes that EPA is well aware that they have developed for
production and introduced other SCR technology (i.e. EGNR) that
provides a maintenance interval in the range of 35,000 to upwards of
45,000 miles.
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\21\ 73 FR 79089 (December 24, 2008).
\22\ 45 FR 4136, 4141 (January 21, 1980).
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IV. Discussion
As set forth above, EPA in its 2007 guidance states that SCR system
maintenance meets the regulatory definition of critical emission-
related maintenance. EPA has further clarified that allowable
maintenance requirements apply to SCR systems, including SCR catalysts,
reducing agent, reducing agent storage tanks, dosing valves, and all
lines and hoses. Additionally, because manufacturers indicated that
packaging constraints would prevent them from being able to equip their
vehicles with reducing agent storage tanks of sufficient size to allow
reducing agent replenishment to comply with required maintenance
intervals of 100,000 or 150,000 miles, EPA clarified that manufacturers
would likely need to request a change to the scheduled maintenance
interval pursuant to the (b)(7) provision.
Also set forth above, manufacturers have in fact requested such
changes for more frequent scheduled maintenance to accommodate DEF
refilling events for previous, current, and future model years. When
EPA reviewed those manufacturer requests in 2009, it determined that
maintenance associated with refill of DEF tanks was new scheduled
maintenance and that the manufacturer-requested maintenance request and
scheduled maintenance intervals were appropriate and announced that
determination in the Federal Register.\23\ The broad-level
considerations EPA evaluated when considering the maintenance interval
requests were the space and weight constraints presented by
incorporating a DEF tank into vehicle design, as well as the impact a
DEF tank's inclusion could have on engine performance. In our 2009
Federal Register notice, we concluded that the requested intervals were
appropriate because we determined that manufacturer-recommended DEF
refill intervals approximated the maximum feasible maintenance
intervals associated with reasonable DEF tank sizes. We also concluded
that the maintenance intervals recommended ensure that the functions
and operational efficiency of such vehicles are not overly compromised.
---------------------------------------------------------------------------
\23\ 74 FR 57671 (November 9, 2009).
---------------------------------------------------------------------------
A. Light-Duty Requests
As EPA explained in its 2009 notice, automobile manufacturers have
stated it takes approximately an 8 gallon DEF tank to ensure that DEF
will last for the length of a typical oil change interval. Assuming an
oil change interval of 10,000 miles, a DEF tank size of approximately
80 gallons would be required to meet a 100,000 mile DEF refill
maintenance interval. Even a 16-20 gallon DEF tank (to meet a 2 oil
change interval) would interfere with the space that is necessary for
typical light-duty vehicle design and transportation needs of the
consumer. Interior cabin volume and cargo space are highly valued
attributes in light-duty vehicles and trucks. Manufacturers have
historically strived to optimize these attributes, even to the point of
switching a vehicle from rear-wheel drive to front-wheel drive to gain
the extra interior cabin space taken up by where the drive shaft tunnel
existed, or switching the size of the spare tire from a conventional
sized tire to a small temporary tire to gain additional trunk space.
Thus any significant interior, cargo or trunk space used to store a DEF
tank would be unacceptable to customers. There are also packaging
concerns with placing a large DEF tank in the engine compartment or in
the vehicles undercarriage. Most vehicle undercarriages are already
crowded with the engine, exhaust system, including catalytic converters
and mufflers, fuel tank, etc. limiting any available space for a DEF
tank.
In addition to the inherently space constrained areas on the
vehicle to place both fuel tanks and DEF tanks (an additional 8 gallon
tank represents a very significant demand for space) the addition of
the weight associated with the DEF represents significant concerns
(e.g. performance and efficient operation) on the operation of the
vehicle. For example, assuming a density of 9 lb/gallon, an 8 gallon
DEF tank represents an additional 72 lbs on a vehicle already looking
to optimize performance. Adding additional DEF tank size to even
accommodate a two-oil change interval is not feasible or practical
given these weight constraints. A requirement for a larger DEF tank may
also have an adverse effect on the ability of a manufacturer to meet
greenhouse gas emission standards and fuel economy standards.
Presently, no manufacturer has presented any indication that things
have changed in any material fashion that would allow for the
installation of
[[Page 494]]
larger DEF tanks and/or less frequent DEF refilling intervals on light
duty vehicles and trucks. More importantly, EPA is aware of no
technological advances in this area and believes that none are likely
to occur in the near future. The space and weight constraints presented
by inclusion of a DEF tank into vehicle design are inherent. Forcing
manufacturers to install larger DEF tanks would not only be impractical
for manufacturers, it would also present utility constraints for
consumers, drivers, and operators. Therefore, alternative maintenance
intervals remain technologically necessary for refilling DEF tanks used
on SCR systems.
EPA notes that the DEF refill maintenance interval being equivalent
to and occurring with the oil change interval is a fairly long interval
(e.g. 7,500 to 12,500 miles) for light-duty vehicles and trucks and is
not likely to result in overly frequent maintenance under typical
vehicle driving. EPA also believes that an adequate DEF supply will be
available to perform the DEF refills at the stated intervals. EPA
believes it important to also consider when, where and how often
vehicle owners or operators are most likely to perform the DEF refill
maintenance. For light-duty vehicles and light-duty trucks, EPA
believes the requested DEF refill interval's association with the oil
change interval is appropriate given the likelihood of DEF availability
at service stations and the likelihood that DEF refill would occur
during such service.
Recognizing that alternative maintenance intervals for DEF
refilling remain technologically necessary due to space and weight
constraints, EPA believes that the above-described alternative
maintenance intervals requested by light-duty vehicle manufacturers are
appropriate.
B. Heavy-Duty Requests
EPA continues to believe it is reasonable to base the DEF refilling
event on diesel refueling intervals given that it is likely that the
DEF refill maintenance would be undertaken at the time of fuel refill
due to DEF infrastructure developed at diesel refueling stations. EPA
agrees with manufacturers that the DEF refilling intervals requested by
EMA, as a threshold matter, are ``technologically necessary.'' EPA
knows of no SCR technology that is currently available that is yet
capable of attaining higher mileage without a DEF refill. Although
Navistar maintains that EPA is aware of its ``EGNR'' technology that it
has ``developed for production and introduced'' that provides a
maintenance interval in the range of 35,000 to upwards of 45,000 miles,
Navistar presents no further evidence regarding this technology.
Navistar has presented no evidence that such technology is currently
available in the marketplace and can meet all requirements of the Clean
Air Act and the regulations promulgated thereunder. EPA knows of no
application for certification of engines using such technology; nor
have any engines using such technology on heavy-duty engines been
introduced within the United States. In any case, such technology would
be different technology than the DEF-based SCR technology being used by
current SCR manufacturers. If engine families using such EGNR
technology become established in the marketplace and can meet all of
the requirements in EPA's regulations, then it might be appropriate to
revisit this issue, although the fact that such technology is
substantially different from DEF-based SCR would be relevant for
determining whether the establishment of this technology is relevant to
the establishment of maintenance intervals for DEF-based SCR.
For vocational vehicles such as dump trucks, concrete mixers,
refuse trucks and similar typically centrally-fueled applications, EPA
believes the DEF tank refill interval should equal the range (in miles
or hours) of the vehicle operation that is no less that the vehicle's
fuel capacity (i.e., a 1:1 ratio). For all other vehicles, EPA believes
the DEF tank refill interval must provide a range of vehicle operation
that is no less than twice the range of vehicle's fuel capacity (i.e.,
a 2:1 ratio).\24\ As EPA has noted previously, assuming that 25,000
gallons of diesel fuel were consumed to reach a 150,000 mile interval
(the interval applicable to catalyst maintenance for heavy-duty
engines), and assuming a 3% DEF consumption rate, 750 gallons of DEF
weighing approximately 6,750 pounds would be required to meet a 150,000
mile maintenance interval for DEF refill. A line-haul truck is allowed
a maximum gross vehicle weight of 85,000 pounds of which approximately
45,000 pounds is for cargo carrying. A DEF tank of this size would
reduce the cargo-carrying capacity by 15%. Another example from the
line-haul industry suggests that a DEF tank size of over 900 gallons
would be needed to reach the 150,000 mile interval for a common highway
vehicle with a diesel fuel capacity of 200 gallons and achieving 6.5
miles per gallon fuel efficiency. Similarly, a medium heavy-duty engine
would require 375 gallons of DEF weighing 3,275 lbs to meet a 150,000
mile interval. EPA believes that such tank sizes are clearly not
reasonably feasible in light of the weight and space demands and
constraints on heavy-duty trucks and the consumer demand for as much
cargo-carrying capacity as possible.\25\
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\24\ As SCR-equipped vehicles uniformly have a constantly
viewable DEF level indicator, EPA is not including a DEF tank refill
interval equal to no less than three times the range of the
vehicle's fuel capacity (i.e., a 3:1 ratio) for vehicles without
such an indicator.
\25\ Navistar states, at page 5 of its comments, that
``[d]eviation from `minimum' maintenance is rare and intended * * *
to be temporary. As noted above, EPA has found that DEF refill is a
new type of maintenance and is not fairly considered as part of the
maintenance of the catalyst covered under (b)(4). In any case, it is
clearly of a different type than normal physical maintenance of an
emission-related part and EPA must make its determination of
maintenance interval based on the particular maintenance being
applied. Even Navistar's comments do not suggest that 150,000 miles
would be an appropriate maintenance interval for DEF refill.
---------------------------------------------------------------------------
The Agency also believes that intervals that are not as long as
150,000 miles but are longer than 2:1 would require DEF tanks that are
too large or too heavy to be feasibly incorporated into vehicles.
Available data show that heavy-duty engines equipped with SCR-based
systems will consume DEF at a rate that is approximately 2%-4% of the
rate of diesel fuel consumption. Because of inherent space and weight
constraints in the configuration and efficient operation of heavy-duty
vehicles, there are size limits on the DEF tanks. Currently, there are
truck weight limits that manufacturers must address when making adding
or modifying truck designs. EPA expects and believes that manufacturers
are taking significant and appropriate steps in order to install
reasonably sized DEF tanks to achieve the DEF refills intervals noted.
For example, manufacturers are taking such steps as reducing the number
of batteries on vehicles despite customer demands or designing space
saver configurations, in some instances extending an already very
limited frame rail distance to incorporate the DEF tanks and SCR
systems, moving compressed air tanks inside the frame rails,
redesigning fuel tank configurations at significant costs, and
otherwise working with significant size and weight constraints to
incorporate DEF tanks. EPA was provided with examples of the
consequences of requiring heavy-duty vehicles to accommodate a DEF
refill interval of 5:1, and the information provided to the Agency
strongly suggested that great compromises would be required in cost,
weight and utility of vehicles. Increased
[[Page 495]]
tank sizes and weights on the magnitude of 150 to 325 lbs. would be
required and in some cases diesel fuel volumes would need to be
reduced. The extra weight associated with the DEF required to meet the
2:1 refill intervals represents a significant challenge to
manufacturers seeking to meet both weight and size requirements for
their vehicle designs. In addition, requiring a longer DEF refill
interval may result in increased greenhouse gases and decreased fuel
economy. EPA believes that in light of the existing tight space
constraints and the overall desire to maximize cargo-carrying capacity
to minimize emissions and meet consumer operational demands, and the
built-in DEF tank size buffer to ensure DEF refills, that the proposed
DEF tank sizes are technologically necessary and are also reasonable
and appropriate. EPA believes that requiring tank sizes above these
ratios will cause increases in space constraints and weight that would
not be appropriate for these vehicles. Similarly, EMA notes that under
its request, manufacturers would employ the 1:1 refilling ratio for
only a small number of vocational applications and those vehicle
applications have very limited vehicle space available to house surplus
DEF. Such applications (e.g., a garbage truck, concrete mixer, beverage
truck, or airport refueler) will also be refueled daily at central
locations. At approximately 0.134 ft\3\ per gallon, any extra DEF would
displace significant space available to vehicle components and
subsystems on both the vocational trucks at the 1:1 refill interval as
well as the 2:1 vehicles.
In its comments, Navistar suggests that a longer DEF refill
maintenance interval in the range of 35,000 to 45,000 miles should be
approved. As noted above, one of Navistar's justifications for this
longer interval is the claim that other technology is available that
would need a maintenance interval no shorter than this. However, as
discussed, EPA has no evidence that such technology is actually
available at this time, nor does EPA believe that the availability of
this other technology would necessarily impact the maintenance interval
needed for DEF-based SCR.
Navistar also argues that engine manufacturers using SCR should
have made efforts to increase DEF-refill intervals since 2009 and that
it is ``certainly feasible'' for SCR systems to meet such a range.
Although Navistar maintains that SCR engine makers can easily quadruple
the refill interval with little or no effort, Navistar suggests one way
to reach this interval is to double DEF tank size, and Navistar makes
no effort to present evidence depicting where such enlarged DEF tanks
can reasonably be located or the effects on such tanks on operational
efficiency. In addition, in determining the minimum maintenance
interval for DEF, Navistar suggests that manufacturers can double
maintenance intervals by lowering engine-out emissions, which would
reduce the DEF dosing frequency and in turn extend the refill interval
for a fixed DEF tank size. The Agency reviewed the potential for engine
manufacturers to lower engine-out NOx through in-cylinder control
techniques such as injection timing retard and exhaust gas
recirculation (EGR). It is clear that lowering engine-out NOx will
directly lower the quantity of DEF that is needed to meet the NOx
standard and hence conceptually might extend the DEF refill interval.
However, as documented in the EPA rulemaking that set a Nonconformance
Penalty (NCP) for the 2004 NOx standards, for the relevant range of NOx
control (around 2 g/bhp-hr NOx engine out) and these specific in-
cylinder NOx control technologies, each one gram of NOx reduction is
expected to result in a 5 percent increase in fuel consumption.\26\ It
can also be estimated that the DEF consumption rate is approximately
one percent of fuel consumption per one gram of NOx reduction. Since
the increase in fuel consumption to reduce NOx by one gram is
approximately five times higher than the increase in DEF consumption to
treat that same one gram of NOx, it is clear that reducing engine-out
NOx in order to extend the DEF refill interval would require an
increase in the fuel tank size five times that of the volume savings in
the DEF tank size in order to keep the same refueling interval. In
other words, reducing engine-out NOx in order to extend the DEF refill
interval while keeping the same diesel refueling interval would cause
the fuel tank to grow larger necessitating a reduction in the DEF tank
volume at a ratio of 5:1. Since that increased fuel tank size would
then necessitate a smaller DEF tank, the resulting service interval
would be shortened not lengthened.
---------------------------------------------------------------------------
\26\ ``Final Technical Support Document: Nonconformance
Penalties for 2004 Highway Heavy Duty Diesel Engines'', EPA420-R-02-
021, August 2002.
---------------------------------------------------------------------------
It could be argued that there's no need to increase fuel tank size
in response to higher fuel consumption rates because operators can
simply refuel at greater frequencies. To this point, it is important to
note that the effective operating range of a vehicle on a single tank
of fuel is a key design parameter that determines the mission
capability of a vehicle. For example, refuse trucks are designed with
appropriate fuel capacity to operate over residential and commercial
customer routes and have enough reserve driving range to then allow
delivery of payload to a landfill often in remote locations. If a
manufacturer maintained fuel tank size and increased the frequency at
which the trucks must refuel, these trucks may not be able to
accomplish their intended mission without making additional stops for
fuel. Fueling stations may not be directly located along the remote
route to some landfills, necessitating unplanned trip deviations. At
the very least, these trucks would be impaired in the ability to
accomplish their mission. Similarly, line-haul trucks are designed with
necessary fuel capacity to deliver freight over significant interstate
distances while minimizing the need for refueling stops. Increasing the
frequency at which the trucks must refuel compromises the ability to
accomplish their mission. Increasing the frequency of refueling stops
poses a serious negative consequence to the end user of these trucks
given their use in commercial applications where the time to accomplish
a mission is business critical. EPA does not believe its allowable
maintenance provisions are intended to drive this type of impact.
Navistar also suggests that SCR engine makers are legally required
to make efforts to improve the time between maintenance for their SCR
systems. However, the regulations do not require this, and EPA must
review the technological necessity of maintenance intervals based on
the existing factual circumstances. Current circumstances do not
indicate that a larger maintenance interval is appropriate. While EPA's
statement made in the 2009 notice indicates that EPA will continue to
monitor the evolution of SCR systems along with urea infrastructure to
determine whether the frequency of DEF refills can be adjusted, this
does not imply that adjustment is necessary or appropriate, or in which
direction such adjustment would go. In addition, regarding Navistar's
reference to a 1980 EPA rulemaking regarding EPA's consideration of the
longest interval that any manufacturer recommends, while EPA does look
at such information, that interval does not necessarily become the
interval determined under (b)(7). In some instances EPA may set an even
more frequent interval and in others the Agency may set a less frequent
interval; EPA's determination of what is a feasible interval for an
engine family or an industry is based on a number of
[[Page 496]]
factors including manufacturer(s) recommended intervals, any physical
or technological constraints, burdens that may be placed on the
operator and what are reasonable expectations of durability from an
operator's perspective, among other factors.
After reviewing this data and information, EPA believes that longer
refill intervals than those noted above would require larger and
heavier DEF tanks, and the design and engineering work performed by
manufacturers thus far indicate that the recommended DEF refill
intervals noted above approximates the maximum feasible maintenance
intervals associated with reasonable DEF tank sizes, given the
substantial negative consequences of longer DEF refill interval
requirements. The maintenance intervals recommended ensure that the
functions and operational efficiency of such vehicles are not overly
compromised. Based on this information we believe the intervals noted
above are warranted.
EPA is not approving a 1:1 DEF maintenance interval across the
heavy-duty engine class at this time. EPA notes that manufacturers have
been meeting a 2:1 ratio for DEF tank size for the past two years and
the commenters have not yet provided sufficient evidence that this
ratio will be infeasible in the future. Moreover, the information EPA
has received to date has not shown that any change in the maintenance
interval is necessary or appropriate throughout the heavy-duty engine
category, rather than for particular applications, or that a refill
interval as low as 1:1, rather than 1.8:1 or 1.5:1, is necessary or
appropriate. EPA recognizes that the implementation of the future
standards for greenhouse gases, beginning as early as the 2013 model
year, may have some implications for this issue, but the SCR Engine
Manufacturers have not shown that these standards, which are phased in
and are not applicable in the 2012 model year, will cause the 2:1
refill interval to be infeasible across the industry, and certainly not
in the 2012 model year. While EPA agrees that the warnings and
inducements in place for failure to replenish DEF will restrict the
ability of operators to run without DEF, and have made operation
without DEF virtually unheard of, a DEF tank ratio of 1:1 will increase
the likelihood that operators will need to make more frequent stops to
replenish DEF, and possibly may need to stop solely to replenish DEF,
which may place a greater burden on the operator in terms of the
frequency of DEF refills.
EPA also notes that the regulations allow any manufacturer to
petition EPA under the ``paragraph (b)(7) process'' for a shorter
maintenance interval for a particular engine family or application than
that approved for the industry if the manufacturer can show that a
shorter interval is the maximum feasible interval necessary for the
particular engine or vehicle configuration being certified.
Navistar and the SCR Engine Manufacturers suggest, respectively,
that the ``likelihood of the maintenance being performed in-use'' is
the touchstone of allowable maintenance, or is the most important
factor in establishing the precise maintenance interval. At the outset,
EPA believes it is important to note the context of the term
``reasonable likelihood of being performed in-use'' within paragraph
(b)(6)(ii). For critical emission-related maintenance (including
critical emission-related maintenance under paragraph (b)(6)(i), as
well as such maintenance as determined by EPA under (b)(7)),
manufacturers are required to show such likelihood prior to performance
of such maintenance on durability test vehicles. Manufacturers can
satisfy this requirement by meeting one of the specified conditions in
paragraphs (b)(6)(ii) (A) through (F). Paragraph (b)(7) does not
specify any additional showing required of the manufacturer should an
alternative maintenance interval for emission-related critical
maintenance be approved. Thus, if a manufacturer can show compliance
with one of the specified conditions in (b)(6)(ii), the manufacturer
has met the regulatory requirement to show a ``reasonable likelihood of
[the maintenance] being performed in-use'' as required under paragraph
(b)(7). As noted in the 2009 notice, SCR engine manufacturers (or
vehicle manufacturers) are using a clearly displayed visible signal
system approved by EPA, meeting the requirements of (b)(6)(ii)(C). In
addition, SCR engine manufacturers are going beyond the minimum
requirements of (b)(6)(ii) and are designing, and are expected by EPA
to design (under the adjustable parameter regulatory provisions) their
systems to include inducements that will adequately trigger the
operators to refill the DEF tanks by reducing vehicle performance to a
point unacceptable for typical driving, which would meet the
requirements of (b)(6)(ii)(A).\27\ Section (b)(7) does not include an
affirmative requirement on the petitioner to demonstrate nor on EPA to
find a likelihood of maintenance being performed beyond that which is
clearly and specifically prescribe at (b)(6). Indeed, although EPA
``noted'' the likelihood of performance in its 2009 notice, EPA did so
in order to provide the regulated community with a complete picture of
how the allowable maintenance provisions should be read together and
how they complement each other. In addition, EPA notes that the
determination of what is maximally feasible under (b)(7) does not
require, or in fact include, a consideration of the inducements (as
described above). EPA nevertheless believes that such inducements
clearly and sufficiently provide the necessary demonstration of
likelihood of maintenance.
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\27\ See EPA's draft guidance at 76 FR 32886 (June 7, 2011).
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Conversely, with respect to the arguments from the SCR Engine
Manufacturers, the fact that maintenance is likely to occur does not
affect the determination of what is the appropriate ``technologically
necessary maintenance interval.'' While the likelihood of maintenance
and the technological necessity of regular maintenance are both
required elements under (b)(7), and the desire to increase the
likelihood of maintenance may inform the particular form of the
maintenance interval (i.e. having DEF refill maintenance be at the same
time as oil change), the two requirements are separate and distinct.
The ``technologically necessary maintenance interval'' requirement is
motivated by a desire to minimize the amount of emission-related
maintenance, which is distinct from the need to make sure that such
maintenance is likely to occur. As noted, the SCR Engine Manufacturers
have not shown that the 1:1 maintenance interval is ``technologically
necessary.'' Therefore, while EPA agrees that the DEF refill
maintenance is likely to occur in use, the 1:1 interval does not meet
the requirements of (b)(7).
V. Approval of New Scheduled Maintenance for SCR Systems
A. Light-Duty Approval
For the reasons set forth above, EPA finds it appropriate to
approve new scheduled maintenance intervals for DEF refill equal to the
scheduled oil change interval for all light-duty vehicles and light-
duty trucks, medium duty vehicles and other chassis certified vehicles
up to 14,000 pounds for 2011 and later model years.
B. Heavy-Duty Approval
For the reasons set forth above, EPA again approves new scheduled
maintenance intervals for DEF based on ratios to a given vehicle's fuel
capacity for engine certified heavy-duty engines and vehicles for 2012
and later model years. Vocational heavy-duty vehicles
[[Page 497]]
(e.g., dump trucks, concrete mixers, refuse trucks, and other
centrally-fueled vehicles) are permitted a DEF tank maintenance
interval no less than the vehicle's fuel capacity (i.e., a 1:1 ratio of
DEF refill to fuel refill). For all other heavy-duty vehicles, EPA
approves a DEF tank refill interval no less than twice the range of the
vehicle's fuel capacity (i.e., a 2:1 ratio).
C. Reasonable Likelihood of Maintenance Being Performed In Use
As stated above, because DEF refills are considered ``critical
emission-related maintenance,'' manufacturers must ``show the
reasonable likelihood of such maintenance being performed in use.'' 40
CFR 86.094-25(b)(6)(ii) and 86.1834(b)(6)(ii) provide a number of means
by which manufacturers may demonstrate such a reasonable likelihood.
Among those means of demonstration are visible signal systems to alert
drivers and operators that maintenance is needed, or data demonstrating
that drivers or operators are induced to perform maintenance. EPA
intends to review specific manufacturer certification applications in
order to review whether these regulatory requirements are met.
D. Applicability
The Agency, as stated above, has approved alternative maintenance
requests to ensure the proper functioning of SCR systems by allowing an
appropriately frequent refilling of DEF tanks. We approve these
requests for all future model years. EPA expressly reserves its ability
to review this approval at any time in the future, should any
technological advances be made that would allow for more or less
frequent DEF refilling or otherwise call this approval into question.
VI. Procedures for Manufacturer Objections
Any manufacturer may request a hearing on this determination. The
request must be in writing and include a statement specifying the
manufacturer's objections to this determination, and data in support of
such objections. If, after review of the manufacturer's objections and
supporting data, we find that the request raises a substantial factual
issue, we shall provide the manufacturer with a hearing in accordance
with 40 CFR 86.1853-01 with respect to such issue.
Dated: December 23, 2011.
Gina McCarthy,
Assistant Administrator for Air and Radiation.
[FR Doc. 2011-33842 Filed 1-4-12; 8:45 am]
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