Hogan Lovells US LLP Columbia Square 555 Thirteenth Street, NW Washington, DC 20004 T +1 202 637 5600 F +1 202 637 5910 www.hoganlovells.com

August 18, 2011

Karl Simon, Director Compliance and Innovative Strategies Division Office of Transportation and Air Quality
United States Environmen tal Protection Agency 1200 Pennsylvania Avenue NW Washington, DC 20460

Re: Request for Updated Scheduled Mainte nance Intervals for Selective Catalytic Reduction Technologies for Model Years 2012 and Later

Dear Mr. Simon:

Pursuant to 40 C.F.R. § 86.094-25(b)(7)(ii), Chrysler Group, LLC, Cummins Inc., Daimler Trucks North America LLC, Detroit Diesel Corpor ation, Ford Motor Comp any, Mack Trucks Inc., PACCAR Inc., UD Trucks Corporation, and Volvo Gr oup North America, LLC, (collectively the “SCR Engine Manufacturers”) hereby request revi sed scheduled maintenance intervals for SCR technologies for model years 2012 and later. S pecifically, the SCR Engi ne Manufacturers request that EPA approve the use of the 1:1 diesel exhaust fluid (DEF) to fuel ratio for vehicles with a DEF level indicator, in addition to vocational vehicles, and that EPA grant its approv al of the reduced SCR maintenance intervals for an indefinite time period or until a point in time when there is compelling evidence that the DEF replenishm ent interval should be revisited. 1 This approval is necessary and appropriate to reflect current and anticipated changes in vehicle des igns, significant changes in inducement strategies, and the incr eased availability of DEF that have arisen since EPA’s November 9, 2009 Approval of New Scheduled Maintenance for Selective Cata lyst Reduction Technologies (the “2009 Notice”). 2

I. Applicable Regulatory Requirements

1 For the SCR Engine Manufacturer companies, this re quest updates their position from that contained in the earlier Engine Manufacturers As sociation’s renewal request dated June 13, 2011. For all of the reasons set forth in this petition, the SCR Engine Ma nufacturers suggest that t he distinction based on the presence of a constantly viewable DEF level indicato r (for the 3:1 ratio) is unnecessary. The many warnings and inducements that manufacturers have bu ilt into their vehicles obviate the need for this

distinction.

2 Control of Emissions from New Highway Vehi cles and Engines: Approval of New Scheduled Maintenance for Selective Catalyst Reduction Te chnologies, 74 Fed. Reg. 57,671 (Nov. 9, 2009).- 2 -

Based on certain conclusions in the 2009 Notice, EPA requires m anufacturers to petition the Agency under 40 C.F.R. § 86.094-25(b)(7 )(ii) (hereafter, just “(b)(7)”) fo r approval of DEF refill rates that are less than the standard regulatory interval for catalyst replacement or maintenance (150,000 miles, or 4,500 hours, for medium and heavy heavy-duty diesel engines). 3 Section (b)(7) sets forth the required contents of a petiti on for an alternative maintenance interval, and establishes the
threshold criteria EPA will use to determine whet her an interval shorter than the regulatory default will be approved.

A. Content of the Petition

A petition for an alternative maintenance interv al under (b)(7) must include the following five pieces of information from the petitioning manufacturers:

i) Need for Maintenance: an explanation of why the maint enance is “technologically necessary to assure in-use compliance with the emission standards”; 4

ii) Category Recommendation: a recommendation as to whetherthe maintenance is emissionrelated or non-emission-related, critical or non-critical; 5

iii) Maximum Feasible In terval Reference Point: information on “the maximum feasible maintenance interval”; 6

iv) Recommended Interval: the specific “interval s uggested” by the manufacturers; 7 and

v) Other Information Supporting Re asonableness of Suggested Interval: “supporting data or

3 In the 2009 Notice, EPA indicated that the replenis hment of DEF is either the “adjustment, cleaning, repair, or replacement” of the “cat alytic converter” or an “add on emissions-related component,” which would make DEF refills subject to these main tenance regulations. 74 Fed. Reg. at 57,672; see 40 C.F.R. § 86.004-25(b)(4)(iii). DEF replenishment is not typica l maintenance, nor “adjustment, cleaning, repair, or replacement,” and is more clearly analogous to per iodic vehicle refueling. The concept of DEF replenishment is also not included in the words us ed to define “scheduled maintenance” at 40 C.F.R. § 86.084-2, which states that it means “adjustm ent, repair, removal, disassembly, cleaning, or replacement of vehicle components or systems whic h is performed on a periodic basis to prevent part failure or vehicle (if the engine were installed in a vehicle) malfunction, or anticipated as necessary to correct an overt indication of vehicle malfunction or failure for which periodic maintenance is not appropriate.” Given that the main tenance regulations were simply not written to contemplate an emissions control technology whose normal operation requires replenishment of a consumable, the SCR Engine Manufacturers have participated in the (b)(7) process as a mechanism for working with the Agency to introduce a new form of emissions cont rol, in a spirit of constructive cooperation.

4 40 C.F.R. § 86.094-25(b)(2), (b)(7)(ii).

5 40 C.F.R. § 86.094-25(b)(7)(ii).

6 Id.

7 Id.- 3 -

other substantiation” for the in terval suggested, whic h becomes a part of the “industry data and any other information available to EPA” that enables EPA to establish “a technologically necessary maintenance interval.” 8

Much of this information was submitted with t he initial 2009 (b)(7) petition and was confirmed by EPA’s 2009 Notice, and therefore needs no further elaboration here. Specifically, EPA has already concluded that replenishment of DEF is “technologically necessa ry” 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. T here has been no change in either the need for DEF replenishment or designation of the category of ma intenance since 2009. This petition asserts that
the 1:1 DEF to fuel ratio now reflects the maximum feasible interval based on reasonable tank sizes, given the latest information available r egarding SCR systems and DEF availability.

B. Threshold Criteria for Approval of Reduced Maintenance Interval

The regulations also provide that EPA will set “a technologically necessary maintenance
interval.” 9 The general maintenance regulations provi de further guidance on w hat “technologically necessary” means where they provide that “[ a]ny emission-related maintenance” “must be technologically necessary to assure in-u se compliance with the emission standards.” 10 Thus, under (b)(7), EPA first makes a threshold determinat ion that the manufactu rers’ recommended scheduled maintenance, at an interval shor ter than the regulatory default, is “technologically necessary to assure in-use compliance with the emission standards.” 11

II. EPA’s 2009 Conclusions

While the (b)(7) regulations establish what information must be included in a petition and that a reduced interval will only be granted for maintenanc e that is “technologically necessary” to assure in-use compliance with the emission standards, EP A’s 2009 Notice establish ed the specific factors
that EPA uses to determine what a reasonable and appropriate technologically necessary interval is for DEF replenishment. The (b)(7) regulations were originally developed to address mechanical engine technology that is subject to w ear, but which is expected to last t he full useful life of a vehicle, or a significant portion of that useful life. In contrast to those mechani cal maintenance items, SCR systems use a consumable that is subject to regular periodi c replenishment by design. The 2009 Notice specifically addressed t he unique nature of liquid DEF repleni shment, and the need to strike a
reasonable balance between conflicting design goals. In doing so, the 2009 Notice established that
EPA’s determination is based on t he “approximate” “max imum feasible maintenance intervals

8 Id. (emphasis added).

9 Id. (emphasis added).

10 40 C.F.R. § 86.094-25(b)(2).

11 Thus the maintenance itself must be technologic ally necessary for compliance. EPA’s 2009 Notice established that the replenishment of DEF tanks at an interval of less than 150,000 miles, or 4,500 hours, is in fact “technologically necessary” to assu re in-use compliance. 74 Fed. Reg. at 57,673.- 4 -

associated with reasonable DEF tank sizes .” 12 More specifically, EPA’s Notice discussed several key factors that EPA uses to determine what is reasonable and appropriate , and explained how each is used in the (b)(7) process.

A. Technological Necessity of an Inter val Less Than 150,000 Miles (or 4,500 Hours)

The regulations use the word s “technologically necessary” in two contexts. First, section (b)(2) requires that all maintenance that meets the definition of “emissi on-related maintenance” “must be technologically necessary to assure in-use complianc e with the emission standards.” 13 Consistent with this provision, (b)(7)(ii) requires that any alte rnative interval set by EPA be “a technologically necessary maintenance interval.” 14 In other words, once some reduced maintenance interval has been found to be technologically necessa ry, EPA may only approve an interval that is reasonable and appropriate, in its discretion, based on the informati on submitted, and other available facts. Thus, the words “technologica lly necessary” describe the category of maintenance that is allowable, but they do not describe what the specific interval must be. The 2009 Notice clearly established that the periodic refilling of DEF (at less than 150,000 miles, or 4,500 hours) is necessary for SCR technology to assure that emission standards are met in-use. 15 In conclusion the Agency stated: “EPA agrees with manufacturers that the DEF refilling intervals requested are technologically necessary. EPA knows of no S CR technology for any he avy-duty engine application that is yet capable of attaining hi gher mileage without a DEF refill.” 16 DEF replenishment remains as “technologically necessary” today as it was in 2009 , and EPA should continue to allow DEF refills at a frequency of less than 150,00 0 miles, or 4,500 hours.

Once the “technologically nece ssary” threshold determination is made for setting a shorter interval, EPA then evaluates the information in the petition, including: i) the maximum feasible interval, ii) the suggested interval, and iii) “other inform ation” to establish the new alternative interval. EPA’s regulations do not require that it set alter native maintenance intervals 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 to enable EPA to evaluat e the reasonableness of the manufacturers’ recommended interval. The maximum possible inte rval for DEF replenishment is established in each case by the total load capacit y of the vehicle in question, the space available for a given DEF tank size, the fuel efficiency and GHG impact of various DEF dosing rate s, the desired operating range of the vehicle between f uel 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 bal anced against the need to carry cargo, or to enable the vehicle to meet the purpose for which it was bu ilt, to determine what is feasible in the most economical way possible while ac hieving compliance. In EPA’ s 2009 Notice, EPA explained that

12 74 Fed. Reg. at 57,674 (emphasis added).

13 40 C.F.R. § 86.094-25(b)(2).

14 40 C.F.R. § 86.094-25(b)(7)(ii) (emphasis added).

15 74 Fed. Reg. at 57,672, 57,673-74.

16 Id. at 57,673.- 5 -

while it may be possible for a line-haul truck to carry the 750-900 gallons of DEF needed to operate for the entire 150,000 mile interval, it would be enti rely unreasonable to require the truck to carry 6,750 or more pounds of DEF, because that would reduce carg o capacity by 15% or more. 17 In short, the 2009 (b)(7) process made it clear that the reduced maintenance interval would never be set at the maximum possible interval. Instead, EPA must set a reasonable, feasible interval, in its discretion, based on a variety of fa ctors and all available information.

B. Likelihood of Being Performed In-Use

The 2009 Notice established that once the technological necessity of a lesser interval has been determined, the likelihood of being performed in-use is the most important factor in establishing the precise maintenance interval. First, 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.” 18 Excessive frequency can only compromise emissions control where it creates a risk that the maintenance will not be performed inuse.

Second, EPA explained that while likelihood of being performed in-use was a specific criteria under (b)(6), it was also a factor that was “impor tant to note” with regard to EPA’s (b)(7) findings, particularly with regard to “critical emission-related maintenance.” 19 EPA then concluded that it was
“reasonable to base the DEF re filling event on diesel refueling interval s given that it is likely that the
DEF refill maintenance would be unde rtaken at the time of fuel re fill due to DEF infrastructure developed at diesel refueling stations.” 20

Most importantly, EPA used the likelihood of performance in-use as the exclusive factor for determining which of the three alternative maint enance intervals would be applicable to a particular type of heavy-duty on-highway (“HDO H”) vehicle. Specifically, EPA established three allowable maintenance intervals in 2009 that were expressed as a ratio of the DEF tank range to the fuel tank range, specifically 1:1, 2:1, and 3:1. The only relevant difference between the applications eligible
for the three different intervals is the likelihood of being refilled in-use. Spec ifically, centrally fueled vocational vehicles were expected to be the most likely to be refill ed in-use, and the interval was set
at 1:1. Vehicles with a const antly viewable DEF level indicator we re anticipated to be the next most likely to be refilled, and the interval was set at 2:1. Finally, vehicl es without a cons tantly viewable level indicator were thought to be less likely to be regularly filled than the other categories, and a longer interval of 3:1 was established.

C. Other Data and Information

As noted above, (b)(7) requires EPA’s determi nation to be “based on industry data and any

17 74 Fed. Reg. at 57,673.

18 Id. at 57,672.

19 Id. at 57,673.

20 Id

.- 6 -

other information available to EPA.” 21 EPA’s 2009 Notice focused on two relevant categories of other industry data: (1) t he technological feasibility of different DE F tank sizes; and (2) the availability of DEF to on-highway users. EPA made two relat ed findings of fact that remain accurate today. First, EPA concluded that DEF tank sizes were lim ited by weight and space constraints, and that tanks larger than those recommended by manufacturers were not reas onably feasible. Specifically, DEF tanks capable of a 150,000 mile range were “clearly not technologica lly feasible in light of the weight and space demands and c onstraints on heavy-duty trucks.” 22 EPA also explained that “longer intervals than those reques ted by the manufacturers would require DEF tanks that are too large or too heavy to be feasibly incorporated in to vehicles. . . . Bec ause of inherent space and weight constraints in the confi guration and efficient operation of heav y-duty vehicles, there are size
limits on the DEF tanks.” 23 In addition, EPA also focused on DEF availability in c oncluding that it
was “reasonable to base the DEF refilli ng event on diesel refueling interval s 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.” 24

Thus, although the phrase “like lihood of being performed in-use” is not used in (b)(7), the SCR Engine Manufacturers agree that that has been, and should continue to be, the primary factor
in EPA’s assessment of what a reasonable proposed main tenance interval fo r DEF replenishment
should be.

III. Significant Changes to Key Factors Have Occurred Since 2009, All of Which Support Expanded Use of the 1:1 Tank Ratio

The 2009 Notice recognized that EPA’s initia l (b)(7) approval may need to evolve as DEF infrastructure and SCR technology change ov er time. EPA explained the following:

The Agency has limited this approval to model years 2009 to 2011 due to the expectation that SCR-relat ed technologies and the urea in frastructure will continue to develop and mature, and EPA plans to revi sit this category of vehicles to determine appropriate future intervals . Should manufacturers continue to believe
that the identified interval or other intervals are technologically necessary or otherwise appropriate after the 2011 model ye ar, we expect them to take this up with the Agency in a timely manner. 25

Significant changes have occurred with respect to each of these key fa ctors, as discussed below. In each case, the changes support the expanded use of the 1:1 tank ra tio as requested by the SCR Engine Manufacturers.

A. Likelihood of Being Performed In-Use

21 40 C.F.R. § 86.094-25(b)(7)(ii).

22 74 Fed. Reg. at 57,673.

23 Id

. 24 Id

. 25 Id . at 57,674 (emphasis added).- 7 -

In the 2009 Notice, EPA indicated that it expec ted that in most cases, DEF would be refilled at each refueling stop. 26 Two developments since 2009 have fu rther increased the likelihood of DEF replenishment at each and every re fueling stop: (1) more severe inducement strategies; and (2) increased availability of DEF.

1. More Severe Inducements

EPA’s 2011 Draft SCR Guidance 27 on SCR inducement strategi es makes it essentially impossible for an SCR vehicle to ope rate without regular DEF repleni shment. Although this is also
true of vehicles certified under ear lier guidance, the dramat ic increase in the severity of DEF level inducements from 2009 to the present is extraordinary and must be taken into account in approving updated maintenance intervals.

Under the December 2009 SCR Guidance, 28 EPA stated that “[i]n det ermining strategies that are sufficiently onerous to cause the driver to replenish the DEF tank and minimize any adverse emission impact, manufacturers can consider strategies that begin to degrade performance prior to the DEF tank being empty and that progressively become more oner ous as the DEF tank becomes empty.” EPA further ex plained: “Possible approaches for t he manufacturer to degrade performance include a derate of the engine’s maximum availabl e engine torque of a sufficient magnitude for the operator to notice decreased operation (a derate of at least 25% is likely to be needed for such an effect) and progressing to further degradation t hat could include operati on of the engine being disabled or severely restricted, implemented in a manner designed to prevent operation without DEF. EPA recognizes that there may be safety concerns regarding a complete di sablement of the engine or severe degradation occurring while the vehicl e is moving, and therefore believes that such degradation would best be initia ted at the time of refueling, parking or restart.” 29

In the 2011 Draft SCR Guidance, EPA proposes t hat, when the DEF tank is empty, final inducement consisting of a 5 mph maximum vehicle speed or engi ne shutdown / idling-only limitation be imposed while the vehicle is in operation

. 30 If manufacturers c hoose to implement final inducement only when the vehicle is stopped in a safe location (identified by a refueling, 60-minute idling, or key-off event), they must design their engines to meet addi tional characteristics , which include imposition of a severe inducement prio r to triggering final inducement. “The severe inducement will consist of an engine derate, a vehicle s peed limitation, or a lim itation on the number of engine restarts .” 31 EPA provides, as an example of an acceptable severe inducement, an engine

26 The 2009 Notice explained that “ operators are expected to refill the DEF a[t] each diesel fuel refilling event.” 74 Fed. Reg. at 57,674.

27 Control of Emissions from Ne w Highway Vehicles and Engines; Guidance on EPA’s Certification Requirements for Heavy-Duty Diesel Engines Usi ng Selective Catalytic Reduction Technology (“2011 Draft SCR Guidance”), 76 Fed. Reg. 32,886 (June 7, 2011).

28 Revised Guidance for Certification of Heavy-Duty Diesel Engines Using Sele ctive Catalyst Reduction (SCR) Technologies (“December 2009 SCR Guidan ce”), CISD-09-04 REVISED, at 5 (Dec. 30, 2009).

29 Id.

30 76 Fed. Reg. at 32,894.

31 Id. (emphasis added).- 8 -

torque derate of 40 percent, which should occur w hen there is enough DEF in the tank to last one full day of operation, or with 10 percent reserve in the tank. 32

In addition, 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 t hat 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 nece ssary, and is therefore more likely to rely on gauge levels, warnings, and induc ements to trigger refills.

2. Increased Availability of DEF

In 2009, centrally fueled fleet vehicles were view ed as the most likely to have DEF available at each refueling stop. DEF infr astructure has developed significant ly since 2009. Today, DEF is as readily available at truck stops and other refueling locations as it was previously expected to be at central fleet refueling centers. Therefore there is no longer any reason to distinguish between centrally fueled operations and line-haul operations from a DEF availability perspective. As EPA noted in its 2011 Draft SCR Guidance: “DEF infr astructure and sales volume have continued to grow since introduction of 2010 model year trucks equipped with SCR systems. . . . DEF is now available for sale in every state at truck stops and service facilities, and is available for delivery to fleet locations, as well.” 33 EPA also stated: “The continually increasing DEF infrastructure and sales volume have resulted in improved DEF availab ility along major truck rout es as well as other locations. . . . Increasing demand supported by sale s volume helps drive t he continuing expansion
of DEF infrastructure.” 34 With widespread availability of DEF, drivers can refill their DEF tanks at the same time that they refuel with diesel, so that a 1:1 ratio is now as appropriate for vehicles with a
DEF level indicator as it is for vocational vehicles.

B. Feasibility of Other Tank Sizes

In the 2009 Notice, EPA concluded that the specific t ank sizes associated with the 1:1, 2:1, and 3:1 ratios were the maximum reasonably feasible “in light of the wei ght and space demands and constraints on heavy-duty trucks.” 35 EPA explained that:

Because of inherent s pace and weight constraints in t he configuration and efficient operation of heavy-duty vehi cles, there are size li mits on the DEF tanks.

. . . The extra weight associated with the DEF required to meet the 2:1 or 3:1 refill intervals . . . represents a significant c hallenge to manufacturers seeking to meet both weight and size requirements for thei r vehicle designs. EPA believes that in light of the existing tight s pace constraints and the overall desire to maximize cargocarrying capacity to minimize emissi ons and meet consumer operational demands,
and the built-in DEF tank size buffer to insu re DEF refills, that the DEF tank sizes
associated with the 2:1 and 3:1 refill inte rvals are technologically necessary. EPA

32 Id.

33 76 Fed. Reg. at 32,887.

34 Id. at 32,891.

35 74 Fed. Reg. at 57,673.- 9 -

believes that requiring tank sizes above t hese ratios will cause increases in space constraints and weight that would not be appropriate for these vehicles.

. . . EPA believes that longer refill inte rvals than those noted above would require larger and heavier DEF tanks, and the design and engineering work performed by
manufacturers thus far i ndicate that the recommended DEF refill intervals noted above approximate the maximum feasible maintenance intervals associated with
reasonable DEF tank sizes. 36

As noted above, the only reason EPA had for imposing the greater burden of 2:1 and 3:1
tank ratios on manufacturers was the belief th at those vehicles had a lower likelihood of being
refilled in-use than vocational trucks. Because that is no longer true, the 1:1 tank ratio would be the maximum reasonably feasible DEF tank size for other vehicles with an equal likelihood of being
refilled in-use.

C. Impact of New HDOH GHG Standards

Several significant regulatory and engi neering developments since 2009 have further increased the size and weight constr aints associated with the previous ly approved tank sizes. First, EPA has announced new fuel economy standards for HDOH trucks, and manufacturers have moved to voluntarily increase the fuel efficiency of their vehicles in advance of th e effective dates of those regulations. 37 Within these regulations, EPA recognize s the impact of weight savings on fuel efficiency and GHG emissions. In addition, m anufacturers have develop ed innovative new DEF dosing strategies to reduce CO 2 emissions. These new strategies may involve increasing the DEF dosing rate. Increasing the DEF dosing rate also ma kes it more and more difficult to satisfy a 2:1 tank size ratio without increasing the size of the DEF tank above t he 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, wi th their accompanying weight increase, in order to accommodate tec hnology advancements dev eloped to reduce CO 2 emissions— tanks that are larger than the tanks EPA determi ned to be the maximum reasonably required in 2009. In addition, this could inadvertent ly cause manufacturers to restri ct application of the most fuel efficient engines to vehicles t hat have reduced range bet ween fuel and DEF refills, such that they
will be unattractive to the line-haul fleets that consume the most fuel.

In addition, future GHG requirements that w ill take effect (2013 for the early compliance option) in the time frame of the requested approva l will also make it increasingly difficult to accommodate 2:1 tank sizes in line-haul truck applic ations. Specifically, improved aerodynamics and excess weight reductions are critical to meet ing the upcoming GHG requi rements. Requiring trucks to carry completely surp lus DEF, and increasing that burden, simply cannot be justified in the face of EPA’s new GHG requirements.

Allowing manufacturers greater fl exibility in sizing their DEF tanks has analogies with other fuel efficiency improvement and GH G emission reduction strategies. With the 1:1 ratio option,

36 Id. at 57,673-74.

37 SeeGreenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and HeavyDuty Engines and Vehicles, 75 Fed. Reg. 74,152 (proposed Nov. 30, 2010).- 10 -

manufacturers who choose to reduce their DEF tank sizes will realize a corresponding weight
reduction. 38 EPA has recognized that reduc tions in vehicle mass, such as by reducing the size of
the DEF tank and amount of exce ss DEF carried, reduce fuel c onsumption and GHG emissions:
“Reductions in vehicle mass reduc e fuel consumption and GHGs by reducing the overall vehicle mass to be accelerated and also through increased vehicle payloads which c an allow additional tons to be carried by fewer trucks consuming less fu el and producing lower emissions on a ton-mile
basis.” 39 For example, EPA has noted that a change in tire design can resu lt in a significant weight reduction: “A tractor’s empty curb weight can be reduced from the replacem ent of dual tires with single wide tires and with the repl acement of steel wheels with hi gh strength steel or aluminum. Analysis of literature indicates t hat there is opportunity to reduce typical tractor curb weights by 80 to 670 pounds, or up to roughly 3 percent, through the use of lighter weight wheels and single wide
tires . . . .” 40

Manufacturers need to be able to use the full a rray of available options to meet the newly finalized GHG standards and to improve the real-w orld fuel economy for their HDOH customers (including off-cycle operations). EPA’s polic ies should allow—if not encourage—increased DEF dosing, which can prov ide a significant CO 2 benefit (for example, by allowing manufacturers to reduce the use of EGR). Increased dosing means increased DEF t ank sizes unless the maintenance intervals are adjusted. Not only woul d increased DEF tank size s be larger than those previously found to be the maximum feasib le, but they would work against the CO 2 benefits manufacturers are trying to attain, by adding weight and making it harder to achieve improved aerodynamics. With all of the SCR warnings and inducements that have been required since the 2009 petition was granted, the importance of maintaini ng any particular tank ratio is now negligible.
It is critical that EPA not tie manufacturers’ hands on CO 2 improvement by imposing arbitrary policies on issues of lesser importance, worki ng at cross-purposes to the goal of CO 2 reduction.

IV. The SCR Engine Manufacturers’ Requests

A. Request for Broader Use of the 1:1 Tank Ratio

For all of the reasons set forth above, the SCR Engine Manufacturers hereby request that the 1:1 tank ratio be approved for v ehicles that have a cons tantly viewable DEF level indicator, just as this tank ratio was previously approved for vocational vehicles. In addition to the reasons set forth above, there are additional policy considerations that favor granting this request.

First, in some cases, manufacturers will c ontinue to use the same 2:1 DEF tanks that have already been engineered into ex isting models, and will use the 1:1 maintenance interval simply to allow increased DEF dosing to improve GHG emissions. In these trucks, the actual tank size ratio
will be somewhere between 1:1 and 2: 1 (for example, 1.8:1). Alte rnatively, some manufacturers

38 For example, on a line-haul truck with a 300 gal lon diesel fuel capacity, assuming a 3% DEF consumption rate, an 18 gallon DEF tank is the minimu m required with the 2:1 maintenance interval. However, if the 1:1 maintenance interval is approved, the DEF tank could be as small as 9 gallons, for a weight savings of 81 pounds (assuming a DEF densi ty of 9 lb/gal) compared to the 18 gallon tank.

39 75 Fed. Reg. at 74,216.

40 Id. at 74,217.- 11 -

may use the 1:1 maintenance interval in order to achieve weight re ductions and improve GHG emissions by offering combinations of DEF and fuel tank sizes that are not allowed with the 2:1 maintenance interval, as de scribed in section III.C.

In addition, an extraordinary investment of time and capital has been made to develop today’s inducement strategies. EPA should recognize this investm ent, and the increased efficacy of the latest inducements by allowing t he broader use of the 1: 1 tank ratio. Allowing this flexibility, which is perfectly c onsistent with EPA’s r egulations and past decisio n-making would enable manufacturers to focus their resources on CO 2 reduction developments, rat her than requiring the reengineering of DEF tanks that ar e already over-engineered for the current generation of vehicles, given the latest inducements and cu rrent wide availability of DEF.

B. Request to Extend the Approval of Updated Scheduled Maintenance Beyond
Two Model Years

The SCR Engine Manufacturers request that EPA grant its approval for the reduced SCR maintenance intervals for a period longer than two model years and recommend an approval remaining effective indefinitely (until such time as compelling evidence may indicate that the DEF replenishment interval should be revisited). A longer approval time period would provide greater certainty for manufacturers fo r planning and design purposes, ther eby reducing costs and improving design development, and it would r educe the administrative burden on the agency. It would be
beneficial for both manufacturers and EPA not to have to renew t he (b)(7) petition and approval process every two years.

* * *

We look forward to your response to this r equest. Please contact us if we can provide any
additional information.



### Sincerely,

R. Latane Montague
Partner latane.montague@hoganlovells.com
D 202.637.6567