488 Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 

1 65 FR 6734 (February 10, 2000). 

2 66 FR 5002 (January 18, 2001). 

3 40 CFR 86.1834–01(b)(4)(ii) and 40 CFR 86.004– 

25(b)(4)(iii). 

4 Id. 

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) 

Dated: December 29, 2011. 

Nathaniel J. Davis, Sr., 

Deputy Secretary. 

[FR Doc. 2011–33829 Filed 1–4–12; 8:45 am] 

BILLING CODE 6717–01–P 

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. 

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: 

dickinson.david@epa.gov. 

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. 

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 emissionrelated 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 lightduty, medium-duty, and heavy-duty 

diesel-cycle engines, emission-related 

maintenance for certain emissionrelated 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

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 nonemission-related, and critical or noncritical). 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 emissionrelated. 

If EPA approves a request for new 

scheduled maintenance, the Agency 

then designates that maintenance as 

emission-related or non-emissionrelated. For emission-related 

maintenance, EPA will further designate 

that maintenance as critical or noncritical. 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 emissionrelated maintenance must have a 

reasonable likelihood of being 

performed in use, as shown by the 

manufacturer.5 Examples of 


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Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 489 

(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 inuse 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 § 86.087–38. 

(F) Any other method which the Administrator 

approves as establishing a reasonable likelihood 

that the critical maintenance will be performed inuse. 

6U.S. Environmental Protection Agency, CISD 

07–07, ‘‘Dear Manufacturer Letter Regarding 

Certification Procedure for Light-Duty and HeavyDuty 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. 

7EPA 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. 

8 74 FR 57672 (November 9, 2009). 

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. 

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. 

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

II. Previous Model Year Approval of 

New Scheduled Maintenance for SCR 

Systems 

In 2009, EPA approved manufacturerspecific 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: 

* * * 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, 


emcdonald on DSK5VPTVN1PROD with NOTICES
490 Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 

9 74 FR 57671, 57674 (November 9, 2009). 

10See 40 CFR 86.1834–01(b)(6)(ii) and 86.094– 

25(b)(6)(ii). 

11The 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. 

12Ford 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. 

13EMA 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 

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

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. 

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.’’ 

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 ‘‘hardpoint’’ packaging issues with attempting 

to place a large DEF tank in the engine 

compartment or in the vehicles 

undercarriage.12

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 


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Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 491 

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, 

Wa ̈rtsila ̈ North America, Inc., Yamaha Motor 

Corporation, and Yanmar America Corporation. 

14EMA 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 builtin 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. 

15EMA expressly states that one of its members— 

Navistar, Inc.—does not support EMA’s request. 

16This 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. 

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

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 inuse. 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. 

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 ‘‘emissionrelated maintenance’’ ‘‘must be 

technologically necessary to assure inuse 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 


emcdonald on DSK5VPTVN1PROD with NOTICES
492 Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 

17EPA made this statement in its 2009 Notice, see 

74 FR at 57673. 

18Letters dated August 18, 2011 and September 

27, 2011 to Karl Simon, EPA, Director, Compliance 

and Innovative Strategies Division from R. Latane 

Montague, Hogan Lovells. 

19Navistar throughout its comments returns to its 

theme that EPA’s certification scheme allows DEF 

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-bycase 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 emissionrelated 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. 

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.’’ 

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 


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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.’’) 

20Navistar 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. 

21 73 FR 79089 (December 24, 2008). 

22 45 FR 4136, 4141 (January 21, 1980). 

23 74 FR 57671 (November 9, 2009). 

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.’’ 

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. 

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 manufacturerrecommended 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. 

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 frontwheel 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 twooil 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 


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494 Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 

24As 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. 

25Navistar 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 emissionrelated 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. 

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

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 SCRbased 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 


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26 ‘‘Final Technical Support Document: 

Nonconformance Penalties for 2004 Highway Heavy 

Duty Diesel Engines’’, EPA420–R–02–021, August 

2002. 

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 cargocarrying 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 ft3 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 incylinder 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/bhphr 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. 

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 


emcdonald on DSK5VPTVN1PROD with NOTICES
496 Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 

27See EPA’s draft guidance at 76 FR 32886 (June 

7, 2011). 

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 heavyduty 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 emissionrelated 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. 

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 


emcdonald on DSK5VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 3 / Thursday, January 5, 2012 / Notices 497 

1 69 FR 38958 (June 29, 2004). 

(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] 

BILLING CODE–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[FRL–9615–9] 

Control of Emissions From New 

Nonroad Compression-Ignition 

Engines: Approval of New Scheduled 

Maintenance for Selective Catalytic 

Reduction Technologies 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice. 

SUMMARY: This notice announces that 

EPA has granted manufacturers new 

emission-related scheduled 

maintenance and maintenance intervals 

for the replenishment of the nitrogencontaining reducing agent for selective 

catalytic reduction (SCR) technologies 

used with nonroad compressionignition (NRCI) engines for 2011 and 

later model years. Replenishment of 

reducing agent for SCR technologies is 

considered critical emission-related 

maintenance. 

FOR FURTHER INFORMATION CONTACT: 

David Dickinson, Compliance Division, 

U.S. Environmental Protection Agency, 

1200 Pennsylvania Ave. NW., (405J), 

Washington, DC 20460. Telephone: 

(202) 343–9256. Email address: 

Dickinson.David@epa.gov. 

SUPPLEMENTARY INFORMATION: 

I. Background 

EPA adopted new emission standards 

for NRCI engines on June 29, 2004.1 We 

expect that many manufacturers will 

use SCR systems to meet the final Tier 

IV NOX reduction requirements for their 

diesel engines. 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 and requires periodic 

replenishment (maintenance) by 

refilling the DEF tank. 

NRCI engine manufacturers are 

required to provide written instructions 

for properly maintaining and using the 

engine, including the emission control 

system, to purchasers of new engines. 

These maintenance instructions, 

including the hours associated with the 

maintenance intervals, also apply to the 

engine during its service accumulation 

for emission testing purposes. 

Maintenance performed on NRCI 

engines is classified as critical emissionrelated maintenance if it includes any 

adjustment, cleaning, repair, or 

replacement of critical emission-related 

components. As set forth at 40 CFR 

1039.125(a)(1), 1039.125(a)(2), and 

1039.125(a)(3), a manufacturer may 

schedule critical emission-related 

maintenance on these types of 

components if certain conditions are 

met, including a demonstration that the 

maintenance is reasonably likely to be 

done at the recommended intervals, and 

depending upon the size of the engine 

and the type of emission-related 

component, an EPA-prescribed 

minimum hour maintenance interval. 

For example, a manufacturer of engines 

below 130 kW may not schedule 

maintenance more frequently than 3,000 

hours for catalytic converters and if the 

engines are at or above 130 kW then a 

manufacturer may not schedule the 

catalytic converter maintenance more 

frequently than 4,500 hours. 

In addition, should a manufacturer 

desire a new or shorter scheduled 

maintenance interval (that it wishes to 

recommend to purchasers and perform 

during service accumulation on 

emission-data engines) not found under 

§ 1039.125(a)(2) and 1039.125(a)(3), and 

instead utilize § 1039.125(a)(5), then the 

manufacturer must submit a request to 

EPA for approval. A request for a shorter 

maintenance interval includes new 

scheduled maintenance on emissionrelated components that were not in 

widespread use with NRCI engines 

before 2011. Requests from 

manufacturers for new scheduled 

maintenance intervals must include: (1) 

A description of the proposed 

maintenance step, (2) the recommended 

maximum feasible interval for this 

maintenance, (3) the rationale with 

supporting evidence to support the need 

for the maintenance at the 

recommended interval, and (4) a 

demonstration that the maintenance 

will be done at the recommended 

interval on in-use engines. 

In considering requests for new 

scheduled maintenance EPA will 

evaluate the information provided to 

EPA and any other available 

information to establish alternate 

specifications for maintenance intervals 

as deemed appropriate. 

EPA believes the existing allowable 

scheduled maintenance hour intervals 

applicable to catalytic converters are 

generally applicable to SCR systems 

which contain a catalyst, but that SCR 

systems are a new type of technology 

and that DEF refills are a new type of 


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