EPA CO2 Standards 

3.0 EPA CO2 Standards...................................................................................................... 2 

3.1 National versus state standards and harmonization of EPA and NHTSA standards 6 

3.2 Form of the standards.............................................................................................. 21 

3.3 Stringency of the standards..................................................................................... 53 

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EPA Response to Comments 

3.0 EPA CO2 Standards 

Several commenters provided comments which touch upon two or more aspects of the 

proposed EPA GHG standards, as they are broken out in this Section of the RTC 

document. Splitting these comments apart according to the organization of this section 

might have caused a loss of the context of the specific comment. Citing the entire 

comment in each relevant subsection would have produced significant duplication. In 

lieu of either of these approaches, we present these integrated comments at a relatively 

high point in the organization of this section (e.g., Section 3.0) where all of the relevant 

specific aspects of the comment are addressed either at that level or at a more 

disaggregated level (e.g., Section 3.1). 

Organization: Ford Motor Company 

National Automobile Dealers Association (NADA) 

New York State Department of Environmental Conservation 

University of Miami, School of Law 

Dr. Walter McManus, Ph.D., of the University of Michigan 

Transportation Research Institute (UMTRI) 

Transportation and Buildings Policy for the State of Massachusetts 

Executive Office of Energy and Environmental Affairs 

Comment:

Ford Motor Company 

Ford supported the President's initiative to bring together key stakeholders and work out a 

solution to enable a single national program for motor vehicle greenhouse gas and fuel 

economy standards. A state-by-state approach to such standards is unworkable for a 

variety of reasons, and would impose hardships on consumers, dealers, and 

manufacturers. [OAR-2009-0472-7082.1, p.1] 

[Ford also submitted these comments as testimony at the Detroit public hearing, See 

docket number EPA-HQ-OAR-2009-0472-6815, pp. 16.] 

[Ford also submitted these comments as testimony at the New York public hearing, See 

docket number EPA-HQ-OAR-2009-0472-4621, pp. 32.] 

National Automobile Dealers Association (NADA) 

Above all else, the final rule must encompass a single national light-duty vehicle fuel 

economy/GHG program that avoids any unworkable patchwork of state laws. The EISA 

mandate for a fleet-wide combined fuel economy average of at least 35 miles per gallon 

(a 40% increase) by 2020, with a commensurate reduction in GHGs of at least 30 percent, 

was Congress’ clear guidance on what a National Program should achieve. Notably, 

EISA’s ambitious Congressional mandate resulted from vigorous public debate and, in 

the end, received virtually universal support from all interested parties. Unfortunately, the 

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EPA CO2 Standards 

proposed National Program downplays EISA’s landmark mandates, opting instead for a 

bureaucratic cobbling of new NHTSA CAFE standards together with separate and largely 

redundant EPA GHG standards. [OAR-2009-0472-7182.1, p.3] 

As the National Program proposal states, “CAFE standards address most, but not all, of 

the real world C02 emissions because EPCA requires the use of 1975 passenger car test 

procedures under which vehicle air conditioners are not turned on during fuel economy 

testing.” 74 Fed. Reg. 49458. EPA’s test procedures used to calculate CAFE standards 

are based on equations involving a carbon balance technique where fuel economy is 

calculated from the measurement of exhaust emissions and an assumption that the 

quantity of carbon in a vehicle’s exhaust gas is equal to the quantity of carbon consumed 

by the engine as fuel. The physics and chemistry involved spell a direct relationship; 

controlling fuel economy controls GHGs and controlling GHGs controls fuel economy. 

Clearly, the most straightforward and elegant National Program would be one with 

NHTSA regulating tailpipe GHGs through its long-established, Congressionallymandated CAFE standards, supplemented by a few appropriately tailored EPA rules 

governing vehicle air conditioning (under Title VI of the CAA), fuel design, and vehicle 

use. Several of the comments below point to areas where EPA’s tortured attempt to 

overlay GHG rules on top of NHTSA’s CAFE standards raise significant issues of 

concern. [OAR-2009-0472-7182.1, p.3] 

In any event, NADA strongly objects to the proposal’s admitted attempt to incorporate 

the fuel economy/GHG rules promulgated by California’s unelected Air Resources Board 

(CARB). CARB’s long history of appropriately addressing mobile source criteria and 

hazardous pollutants, in no way justifies incorporation of its GHG rules as they are 

neither practically necessary to nor legally appropriate for a well-designed National 

Program. It is in this light that NADA recently challenged EPA’s reversal of its prior 

denial of CARB’s request for authority to regulate motor vehicle fuel economy and 

GHGs. NADA ‘s legal challenge has nothing to do with the propriety of raising 

fuel economy standards, but rather arises from the unworkable impact on dealership new 

vehicle commerce that would result from a “patchwork of state—based regulations. 

Notably, nothing in EISA changed EPCA’s explicit preemption of the adoption or 

enforcement of laws “related to” fuel economy by states, an express preemption 

necessary to ensure national uniformity and to avoid a patchwork of state-by-state 

mandates. CARBs “flat standard” approach to regulating motor vehicle fuel economy and 

GHGs clearly fails to account for all relevant criteria necessary to a National Program, 

directly relates to and conflicts with the federal CAFE standards, and unquestionably 

undermines the safety. job loss, equity. and consumer choice considerations mandated by 

EPCA. [OAR-2009-0472-7182.1, p.3] 

The National Program very ambitiously proposes to pull forward EISA’s 2020 target by 

four years. Recently, a top EPA official stated that EPA and NHTSA have “put together a 

single national standard with one implementation.” Cobbled together and christened the 

“National Program,” the proposal in reality is not a “single national standard,” but three 

fuel economy standards separately administered by NHTSA, EPA and CARB. The 

proposal claims that the National Program will be “harmonized” and “consistent, “ yet it 

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EPA Response to Comments 

is virtually impossible for the CAFE program, the CAA, and CARB’s regulations 

(designed to regulate GHGs only from light duty vehicles produced for sale in California) 

to be so as each agency must follow separate statutory frameworks. The National 

Program is in fact three different fuel economy standards, set by three different agencies, 

governed by three different laws. [OAR-2009-0472-7182.1, p.5] 

Automakers producing light-duty vehicles for sale in MYs 2012-2016 will have to 

comply with all three standards, even when their mandates and policies conflict. This 

makes for an unnecessarily complex and costly regulatory program with scant (if any) 

commensurate additional benefits. While the proposal gives lip service to harmonizing 

these three mandates, in reality it falls far short in that regard. For example, it fails to 

adequately rationalize and equalize GHG tailpipe emissions between the NHTSA and 

EPA standards. Perhaps one solution to this specific issue would be for NHTSA to adjust 

its curves downward to better reflect the contribution A/C improvements will make to 

overall GHG reductions. [OAR-2009-0472-7182.1, pp.5-6] 

Curiously, the proposal fails to establish a “ratable” ramp-up of fuel economy targets. 

The worst example of this is the unjustifiably large jump between MYs 2011 and 2012. 

Put simply, the proposal’s standards require too much, too soon. Given the unprecedented 

targets proposed for MY 2016, the National Program should adopt a more equitable and 

linear rate of annual increase for MYs 2011-2016, and even should consider back loading 

higher increases into the later model years. NADA does not suggest what targets are 

feasible or practicable for any given model year, as such determinations depend on an 

appropriate evaluation of vast amounts of often confidential business data viewed in the 

light of statutory criteria and numerous assumptions. Of course, an ongoing evaluation of 

manufacturer product plan information is essential, as exemplified by NHTSA’s recent 

request for future data. The feasibility and practicability of compliance changes with time 

for many reasons, not the least of which is the ability of economically constrained vehicle 

manufacturers to develop and implement new technologies, and the willingness of the 

motoring public to pay for those new technologies if and when they choose to buy or 

lease a new vehicle. [OAR-2009-0472-7182.1, p.6] 

Ultimately, any National Program cannot impose standards beyond those deemed to be 

“maximum feasible.” “Economic practicality” is one key criterion for making that 

statutory determination, and any analysis of such must recognize, preserve, and capitalize 

on consumer choice and affordability. Again, unless and until vehicles covered by CAFE 

standards are actually purchased, projected fuel economy and GHG reduction benefits 

will be illusory. Moreover, all three standards must take into account impacts on new 

passenger car and light truck dealerships. Dealerships directly purchase the vehicles 

produced by manufacturers. If the National Program mandates vehicles that are 

unacceptable to the motoring public for cost or performance reasons, potential new 

vehicle customers predictably will hold on to their existing vehicles longer or will turn to 

the used vehicle marketplace. The result: unwanted new vehicles languishing on 

dealership lots, with a decline in dealership sales, income, profits, and employment, and a 

predictable rise in business failures. [OAR-2009-0472-7182.1, p.6] 

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EPA CO2 Standards 

[National Automobile Dealers Association also submitted these comments as testimony 

at the New York public hearing, See docket number EPA-HQ-OAR-2009-0472-4621, pp. 

80-84, 88-89.] 

New York State Department of Environmental Conservation 

New York will deem vehicles that comply with the new federal standards to be in 

compliance with its adopted state standards from 2012 through 2016. We wish to 

emphasize that the Clean Air Act provision of states' rights to adopt motor vehicle 

standards - for California under Section 209 and for other states under Section 177 - was 

crucial in allowing New York and other states to lay the groundwork and create the 

momentum for this national vehicle GHG emissions reduction program, as it was for 

many other previous ground-breaking mobile source regulatory programs. Therefore, our 

statutory right to adopt more rigorous motor vehicle standards than the federal 

government's proved to be a valuable catalyst for innovation and progress. [OAR-2009-

0472-7454, cover page 2] [New York State Department of Environmental Conservation 

also submitted these comments as testimony at the New York public hearing, See docket 

number EPA-HQ-OAR-2009-0472-4621, pp. 13-16] 

The New York State Department of Environmental Conservation (Department) agrees 

with EPA's stated goal of increasing the stringency of greenhouse gas emissions 

standards at a rate such that manufacturers can comply by making emissions reductions 

as part of regularly scheduled vehicle redesigns. We believe that the proposed standards 

are reasonably achievable, and are phased in at an appropriate pace. [OAR-2009-0472-

7454, p.1] 

University of Miami, School of Law 

The time frame of the proposed rule nevertheless poses some concern. The standards 

should not cease to apply in 2016, but should remain in effect until a comparable or more 

stringent standard is permanently in place. Before drafting the rule, the EPA should make 

sure to explore other related transportation-emitters that could be regulated as part of this 

effort. In this way, the standards can be applied to more than 60% of emissions from 

transportation. [OAR-2009-0472-6770, p. 1] 

Dr. Walter McManus, Ph.D., Research Scientist, University of Michigan 

Transportation Research Institute (UMTRI) 

EPA and NHTSA have proposed a new methodology for analyzing potential CAFE and 

GHG emissions standards that is more transparent, replicable, and accurate that the prior 

methodology. [OAR-2009-0472-3651.1, p.3] 

Among other objectives, Congress wants fuel economy standards that balance the 

benefits from reducing negative external effects of fuel consumption with the costs of 

improving vehicle fuel economy. The benefits can generally be estimated with public 

data, but to estimate the costs it would be helpful to use private information on costs 

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EPA Response to Comments 

known only to the automakers. This information asymmetry has the potential to introduce 

“gaming” into the process. [OAR-2009-0472-3651.1, p.3] 

 [[Dr. McManus, also submitted these comments as testimony at the Detroit public 

hearing, See docket number EPA-HQ-OAR-2009-0472-6185, pp. 36-37.] 

Transportation and Buildings Policy for the State of Massachusetts Executive Office 

of Energy and Environmental Affairs 

As a result of the differences in the EPA and NHTSA statutes, there are two key areas 

that I would like to highlight. First, in the proposed rulemakings, the GHG benefits 

estimated from the EPA-proposed, footprint-based standard, expressed as grams per mile 

or CO2 are slightly higher than what NHTSA's proposing for CAFE. This is primarily 

because the CAFE standards do [EPA-HQ-OAR-2009-0472-4621, p.24] not account for 

greenhouse gas emissions from vehicle air conditioning systems. In contrast, EPA gives 

the automobile manufacturers the ability to obtain credit for reducing CO2 and 

hydrofluorocarbon emissions from air conditioning systems. We believe EPA's approach 

is correct; requiring additional reductions from air conditioning systems represents, 

quote, a whole vehicle approach which is appropriate. [EPA-HQ-OAR-2009-0472-4621, 

p.25] 

EPA Response:

As indicated by the organization of Section 3, there are many important aspects of the 

EPA GHG standards for motor vehicles. We have attempted to separate the comments 

received according to their primary focus and address each group of similar or 

comparable comments together in a cohesive manner. The comments cited above in 

Section 3.0 interweave many of these aspects in a way that was not easily separable. 

Rather than repeating these comments in two or more of the following sub-sections of 

Section 3.0, we present these comments here together. The issues which they raise, 

including the interaction between state and federal programs, the overlap of the NHTSA 

and EPA standards, the overall stringency of the NHTSA and EPA standards, the 

stringency of the 2012-2016 standards (including the issue of EISA’s direction to 

NHTSA for a ratable increase in the standards through 2020) and the desirability of 

carrying the current approach to standard setting forward beyond the 2016 model year 

will be addressed as each of these issues is focused on more specifically in the various 

sub-sections of Section 3.0 of this RTC document. 

3.1 National versus state standards and harmonization of EPA and NHTSA 

standards 

Organization:Center for Biological Diversity 

Environmental Defense Fund 

Alliance of Automobile Manufacturers (Alliance) 

New York University School of Law, Institute for Policy Integrity (IPI) 

General Motors 

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EPA CO2 Standards 

Volkswagen Group of America (Volkswagen) 

BMW of North America, LLC (BMW) 

National Association of Manufacturers (NAM) 

Senator Fran Pavley, California State Senate 

Consumer Federation of America 

University of California, Los Angeles School of Law 

State of New Jersey 

State of Washington Department of Ecology 

Environment New Jersey 

Comment:

Center for Biological Diversity 

C. The Effect of Other Motor Vehicle Standards on Fuel Economy Supports More 

Stringent Standards 

California has consistently led the way in seeking to set higher mileage standards, and is 

a leader in the regulation of GHG emissions. Undoubtedly, this trend will continue. Thus, 

the ability of California to seek additional waivers in the future to continue in this 

leadership role argues for the setting of more stringent national standards as well. [OAR2009-0472-7265.1, p. 19] 

Alliance of Automobile Manufacturers (Alliance) 

In addition, the Alliance supports creation of an effective single, national program that 

automakers can plan to meet and that will minimize the disruptions of multiple programs 

on vehicle choice and availability. The Administration fundamentally has accomplished 

this objective for the 2012-2016 timeframe. Beyond 2016, this goal must still be pursued. 

It is important that all key stakeholders, including California and states adopting 

California standards, be included in this process. It is also critical that the Federal 

government continue working to develop an integrated approach that addresses 

infrastructure, vehicles, fuels and fuel quality, and consumer behavior, as well as all other 

sectors of the economy. [OAR-2009-0472-6952.1, pp.1-2] 

Harmonization of EPA and NHTSA S-Curves 

Harmonization between the EPA and NHTSA programs is critical to meeting the 

National Program’s target of 250g CO2/mile by MY 2016. Both agencies stress the 

importance of harmonization in the May 22, 2009 Notice of Intent, where the word 

harmonization is mentioned nine times. The Notice of Intent describes key elements of 

the National Program as follows: 

EPA and NHTSA intend to propose two separate sets of standards, each under their 

respective statutory authorities. EPA expects to propose a national CO2 vehicle emissions 

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EPA Response to Comments 

standard ....NHTSA expects to propose appropriate related CAFE standards. [OAR2009-0472-6952.1, p.31] 

EPA standards recognize the CO2 benefit from investing in air conditioning technology 

improvements, whereas NHTSA’s standards are constrained from doing so. Since the 

agencies are taking different approaches to reaching the same 2016 goals, the National 

Agreement states that a manufacturer should be able to build a single national fleet of 

light-duty vehicles that simultaneously satisfy the requirements of both programs. For a 

single product plan to meet both the EPA and NHTSA approaches, the stringency of the 

tailpipe CO2 standards must be equivalent between the two programs. However, the 

stringencies of the tailpipe standards are not equivalent in the proposed rule. A primary 

reason for this lack of equivalency is the air conditioning assumptions being made in the 

translation between the NHTSA and EPA standard curves. [OAR-2009-0472-6952.1, 

pp.31-32] 

Manufacturers that employ a higher level of A/C system advancements will not realize 

the benefit under the NHTSA CAFE program. If the NHTSA curves fail to recognize the 

A/C system improvements a manufacturer may make under the EPA framework, the 

curves could have the unintended consequence of discouraging A/C system 

improvements. This disconnect, effectively leads to a more stringent overall National 

Program than is contemplated by the Notice of Intent. [OAR-2009-0472-6952.1, pp.33-

34] 

As an example, one manufacturer may want to implement alternative refrigerants as 

quickly as possible. EPA recognizes the benefits of low GWP refrigerants and rewards 

this with 14.9 g/mi credit. If the manufacturer’s strategy was to do this on half of its 

vehicle fleet in MY 2012, the manufacturer would earn 14.9 g/mi CO2e divided by two, 

or 7.5 g/mi CO2e credits for the refrigerant portion alone (plus other indirect credits). 

This is more than twice the average credit level assumed. A strategy like this may be the 

most technologically feasible way to overcome the steep near term increase in the MY 

2011-2012 standards, while the manufacturer is implementing the longer lead time fuel 

efficiency strategies. [OAR-2009-0472-6952.1, p.34] 

This same manufacturer may determine that the best and most economically practicable 

way (given the capital constraints currently faced by the industry) for complying with this 

rule is to maximize A/C improvements in combination with fuel economy improvements. 

The current NHTSA S-curve translation would penalize this approach even though 

equivalent GHG reductions would be achieved. [OAR-2009-0472-6952.1, p.34] 

The issue here has to do with harmonizing the two rules – a key objective of a successful 

National Program. Manufacturers still have to meet the overall stringency of the joint 

program. [OAR-2009-0472-6952.1, p.34] 

Recommendation 

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EPA CO2 Standards 

NHTSA needs to adjust the S-curves downward for 2012-16 model years to allow for the 

potential strategy of pursuing maximum A/C improvements to lower GHG emissions. 

The Alliance’s proposed adjustments can be accomplished without backsliding from the 

MY 2011-15 fuel economy standards published in the April 2008 NHTSA NPRM (and 

later withdrawn). 73 Fed. Reg. 24,352 (May 2, 2008). [OAR-2009-0472-6952.1, p.34] 

The table below quantifies the difference in CO2e between the April 2008 NPRM and the 

September 2009 NPRM. The difference in CO2e quantity (shown in column E) could be 

used without backsliding from the April 2008 NPRM. NHTSA should re-translate the 

EPA S-Curves by the amount in Column G. There would be no environmental loss with 

such an approach because a manufacturer that does not pursue maximum air conditioning 

credits would be required to achieve the necessary CO2 reductions through tailpipe 

emissions. [OAR-2009-0472-6952.1, p.34] 

Consideration of EPA's 2012-2016 Model Year GHG Standards 

With respect to EPA's 2012-2016 GHG standards, it is important to note that the current 

joint NPRM is the result of an agreement in principle between the federal government, 

California, and the automakers in support of one national program for GHG and fuel 

economy standards for model years 2012-2016. Under the agreement in principle, EPA 

and NHTSA are working together to ensure that their respective standards are 

harmonized as closely as possible, in keeping with the joint rulemaking notice. 

Obviously, the harmonization effort requires both agencies to be aware of and 'consider' 

what the other is doing, so they can make adjustments that align the requirements of both 

the GHG and fuel economy programs. As evidenced by the NPRM, NHTSA and EPA 

have been engaged in the harmonization effort for some time now, and they should 

continue in that effort to the conclusion of the joint rulemaking process. This will fulfill 

NHTSA's obligation to 'consider' EPA's GHG rules under Section 32902(f). Of course, 

the process of 'considering' and harmonizing with EPA's GHG rules does not eliminate 

NHTSA's obligation to set standards that conform to the other criteria set forth in EPCA. 

For example, NHTSA must see to it that nothing resulting from the harmonization effort, 

or any other aspect of the standard-setting process, will result in fuel economy standards 

that are not technologically feasible or economically practicable. NHTSA has an 

independent obligation under EPCA to make sure that those criteria are satisfied under 

any final rule. Likewise, any regulations adopted by EPA under the Clean Air Act for 

model years beyond the scope of the current proposal must be consistent with the goals 

and purposes of EPCA and must respect NHTSA’s primary role in setting fuel economy 

standards in consultation with EPA and other agencies. [OAR-2009-0472-6952.1, p.66] 

Consideration of California's 2012-2016 Model Year GHG Standards 

Under the agreement in principle mentioned above, the California Air Resources Board is 

expected to promulgate amendments to its regulations providing that compliance with the 

federal GHG/fuel economy program is deemed to satisfy compliance with the California 

program. Under this framework, as the Alliance understands it, the California GHG 

standards will have no independent practical impact on fleet-wide fuel economy in the 

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EPA Response to Comments 

2012-2016 time frame. Assuming that the agreement in principle is carried out as 

anticipated, the existence of California GHG regulations for the 2012-2016 model years 

should therefore not have any impact on NHTSA's standard-setting process. [OAR-2009-

0472-6952.1, p.66] 

Consideration of EPA or CARB GHG Standards for the 2017 Model Year and Beyond 

The Alliance and all stakeholders have agreed that the best approach to control mobile 

source GHG emissions is through a national program. The Alliance supports the concept 

of a national program beyond the 2016 model year and urges all other stakeholders to do 

likewise. The Alliance is confident a national approach can and will be achieved for the 

post-MY 2016 time frame, and we will work diligently towards that goal. Assuming the 

'one national program' approach continues beyond 2016, and the standard-setting process 

for 2017 and beyond is conducted under a joint rulemaking much like the current one, 

NHTSA's obligation to consider EPA's GHG rules under Section 32902(f) would be 

similar to what is outlined above for the 2012-2016 time period. [OAR-2009-0472-

6952.1, pp.66-67] 

New York University School of Law, Institute for Policy Integrity (IPI) 

(3) Program Choice 

The program proposed by EPA builds largely on the structure of its previous regulatory 

programs, taking the form of traditional command-and-control regulation. [OAR-2009-

0472-7232.3, p. 14] 

EPA has submitted its positive endangerment finding on greenhouse gas pollutants under 

Section 202 of the Clean Air Act (CAA) to the White House Office of Management and 

Budget for final approval. Once that finding is finalized, the CAA requires EPA to 

promulgate regulations. As explained in IPI’s report, The Road Ahead, the statutory 

language in Title II of the CAA limits EPA in its choices to regulate under this section; 

regulations must be in the form of emissions standards mandating some type of limit on 

GHG emissions. These types of command-and-control regulations will be detrimental to 

any subsequent cap-and-trade system that covers GHG emissions from vehicle fuel, 

whether created by Congress or by EPA. [OAR-2009-0472-7232.3, pp. 14-15] 

Assuming California’s existing standards for motor vehicle emissions are close to 

efficient, EPA’s attempt to harmonize its proposed GHG standards with Californian 

policy is the optimal regulatory choice. This harmonization will minimize any inefficient 

interaction of the standards with a subsequently enacted cap-and-trade system, by 

creating a single uniform regulatory regime. Through this method, EPA avoids increasing 

regulatory obligations on (or creating regulatory uncertainty for) car manufacturers, as 

manufacturers already need to comply with similar regulations for cars sold in California 

and the seventeen other states that have adopted California’s standards. [OAR-2009-

0472-7232.3, p. 15] 

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EPA CO2 Standards 

Although the proposed GHG regulations fulfill EPA’s legal duty under Section 202, the 

program does not reach an efficient level of GHG reductions in the transportation sector. 

The proposal does not create a uniform regulatory framework applicable to all mobile 

sources and does not effectively maximize social welfare or minimize costs. In April 

2009, IPI submitted a rulemaking petition to EPA requesting the creation of a 

comprehensive cap-and-trade system under Section 211 of the CAA for vehicle fuel used 

in all mobile sources. A cap-and-trade rulemaking would be more effective at addressing 

GHG emissions of all mobile sources, including sources such as off-road vehicles and 

marine vessels, which are not subject to a similar statutory scheme as light-duty vehicles. 

It would also allow EPA to regulate emissions at the source of fuel sale, manufacture, and 

import rather than requiring piecemeal command-and-control regulation of various 

vehicle sectors. The outlines of such a program, and the statutory authority for the 

program under the CAA, are more clearly outlined in IPI’s petition and IPI’s report The 

Road Ahead, included as attachments to these comments. [OAR-2009-0472-7232.3, p. 

15] 

General Motors 

Our working together in a common direction on a single national approach could 

accomplish much more, consistent with the energy needs and the environmental priorities 

of the country. We knew then only about the framework for the proposed regulations. 

But we made clear that we were prepared to work with EPA and NHTSA, and in that 

regard, I appreciate this opportunity to testify today to reaffirm GM's commitment from 

last May and to comment briefly on the proposed rules of the two agencies. [OAR-2009-

0472-6185, pp.9-10] 

Volkswagen Group of America (Volkswagen) 

Volkswagen has concern that the relative stringency between the EPA GHG proposed 

regulation and the NHTSA CAFE: regulation is not equivalent. It is our understanding 

that the EPA regulation would be more stringent than the NHTSA regulation due to the 

credit flexibility offered under the EPA GHG proposal. The preamble speaks at length 

about the need for harmonization and the effort spent to harmonize the NHTSA CAFE 

program and the EPA GHG requirements under a National program. We expected the 

stringency published for the EPA GHG as the 250 gram/mile combined car and truck 

fleet target as outlined by the President's announcement on May 19, 2009 was a given 

value that the collective automotive companies and other stakeholders could agree to. In 

the joint NPRM, however, we were surprised to see the stringency of the NHTSA curves 

when they are converted to a CO2 basis. The NHTSA curves match the stringency of the 

EPA targets, especially in the earlier years of the regulation. In particular, the 2012 MY 

curves are essentially the same when the NHTSA curve is converted to a CO2 basis. This 

is troubling because we do not believe this increased stringency of the NHTSA targets 

allows manufacturers complete confidence they can build a single fleet that complies 

with both regulations. During negotiations earlier this year leading up to the 

announcement of the National agreement it was thought that if a manufacturer complied 

with the EPA GHG regulation that in turn meant that the manufacturer also complied 

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EPA Response to Comments 

with the NHTSA CAFE regulation. Based on the current CAFE targets published in the 

NPRM we see the possibility that manufacturers can achieve the EPA targets but not the 

NHTSA targets, leading to the situation where a manufacturer could comply with the 

EPA regulation but still pay a CAFE penalty. We ask the agencies to examine this 

possibility and adjust the NHTSA targets to allow the regulations to be better 

harmonized. As discussed in the Alliance comments, we agree that this issue is due to the 

air conditioning credit NHTSA is assuming as they establish their curves. We 

recommend that the offset between the EPA and NHTSA curves should be constant and 

should be based on the maximum A/C credit that can be realized under the CO2 

compliance requirements. This provides incentive to reduce GHG emissions through the 

use of improved A/C system. As is mentioned several times in the regulation, the goal is 

to set the relative levels of the standard to, 'represent a harmonized approach that will 

allow industry to build a single national fleet that will satisfy both the GHG requirement 

under the CAA and CAFE requirements under EPCAIEISA' (Federal Register, Monday, 

September 28, 2009, page 49468, Section 2, Level of the Standards). [OAR-2009-0472-

7210.1, pp.4-5] 

CO2 uses a sales-weighted fleet average calculation. CAFE uses a harmonic salesweighted fleet average calculation. We only note that a consistent calculation method 

between the two regulations may be preferred. If changes are made to harmonize the 

calculation method, however, the relative stringency of the regulations must be 

maintained. [OAR-2009-0472-7210.1, p.9] 

BMW of North America, LLC (BMW) 

[These comments were submitted as testimony at the New York public hearing. See 

docket number EPA-HQ-OAR-2009-0472-4621, pp. 136.] 

We also would like to mention 25 that we very much appreciate the collaboration of the 

State of California in helping to make this National Program a reality. The greenhouse 

reduction targets of California have been met with a single national standard. [These 

comments were submitted as testimony at the New York public hearing. See docket 

number EPA-HQ-OAR-2009-0472-4621, p. 137.]] 

National Association of Manufacturers (NAM) 

NAM supports the Administration’s broader policy objectives of harmonizing vehicle 

emission standards under a National Program and promotion of energy efficiency through 

enhanced CAFE standards through the Department of Transportation (DOT). Not only 

does establishment of national, uniform standards have the potential - if implemented 

correctly- to create a climate of investment certainty necessary to make long-term 

business decisions, but stronger energy efficiency objectives will also enhance domestic 

energy security, which is a key policy priority for manufacturers. The NAM applauds the 

Administration’s objective to mitigate the additional costs that manufacturers would 

otherwise face in having to comply with multiple sets of federal and state standards. 

[OAR-2009-0472-7215.1, p.1] 

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EPA CO2 Standards 

The NAM supports the Administration’s goal to harmonize fuel efficiency standards by 

implementing a federal rule that will pre-empt disparate state and regional programs. 

However, manufacturers believe that the process established by EPA, by using the Clean 

Air Act as its primary statutory vehicle, is deeply flawed and will have the unintended 

and unmanageable consequence of triggering regulation of millions of stationary sources. 

By resorting to the CAA, the EPA has established a process that will undermine private 

and public efforts to recover from the deepest economic downturn since the 1930s. 

Alternatively, the EPA should promulgate a rule that adequately decouples the goal of 

achieving greater fuel efficiency and reduced light-duty vehicle GHG emissions from the 

consequence of regulating GHG emissions from millions of stationary facilities. Any 

failure to do so will inflict harm on the manufacturing sector for which the NAM must 

seek appropriate remedies, legislative or otherwise. [OAR-2009-0472-7215.1, p.5] 

Senator Fran Pavley, California State Senate 

One of the cornerstones of the agreement underpinning these proposed regulations is that 

it strongly reiterates California’s authority under the Clean Air Act to set its own 

greenhouse gas standards as part of the national program, and California will continue to 

be able to set new standards once the program expires in 2016. It is absolutely essential 

that any ruling to extend the federal program beyond 2016 does not either consciously or 

inadvertently create de-facto preemption for California and other states to move forward 

with their own programs, including further regulations for automobiles and trucks. State 

actions not only enable and accelerate progress toward emissions reduction goals, but 

also help spur technological innovation that will benefit the entire country. This is 

absolutely crucial because of California’s special challenges to meet air quality standards 

to protect our citizens’ health and safety. [OAR-2009-0472-7275.1, p.4] 

[Senator Fran Pavley also submitted these comments as testimony at the Los Angeles 

public hearing. See docket LA EPA Hearing EPA-HQ-OAR-2009-0472-7283, pp. 13-20] 

Consumer Federation of America 

From a policy perspective, it is critically important that the Clean Air Act’s framing of 

standard setting, which allows EPA to take a long-term view and a technology-forcing 

role, is being joined to the NHTSA approach. It must shake the standard setting process 

out of its lethargy. The decision to join NHTSA and EPA creates the opportunity for a 

major improvement in the regulation of automobiles because the Clean Air Act allows 

EPA to take a longer-term view with greater flexibility. Moreover, the lengthy discussion 

of the failure of the market to yield an efficient outcome with respect to energy efficiency 

presented in Section II has two critical purposes in these comments and the process of 

standard setting for both fuel economy and tailpipe emissions. 

First, the explanation of why the vehicle fleet is less efficient than it should be is critical 

to understanding why fuel economy standards are the right policy to address the problem 

and how those standards should be set. The explanation of the “efficiency gap” (the gap 

between the optimal level of efficiency and the level the marketplace yields) involves a 

3-13 
EPA Response to Comments 

host of market imperfections, barriers and obstacles on both the supply and the demand 

side. Our analysis shows that setting fuel economy standards is an ideal approach to 

addressing the market imperfections, barriers, flaws and obstacles that underlie the 

market failure. 

Second, and more importantly, the law and practice of setting fuel economy standards at 

NHTSA under the Energy Policy Conservation Act have severely restricted the ability of 

the agency to set fuel economy standards in the public interest (see Exhibit II-13). 

Standards are the right policy instrument, and EPA is the right agency to take the lead for 

a variety of reasons 

First, NHTSA is required to achieve only a 35-mile per gallon standard by 2020, but 

beyond that there is no mandate to achieve higher levels of fuel economy. In contrast, as 

a result of a recent Supreme Court ruling, EPA is obligated under the Clean Air Act 

(CAA) to regulate tailpipe emissions of pollutants, such as carbon dioxide. 

Second, NHTSA is severely constrained in the time frame for which it can set standards. 

It must give the automakers at least 18 months advance notice of what the standard will 

be and it cannot set standards more than 5 years in advance. This narrow window for 

standard setting is too short for effective long term planning. The rulemaking period 

barely covers a full product design cycle. NHTSA has repeatedly said that the time frame 

is too short to ask the industry to do too much. The short time horizon shortchanges the 

public. EPA is not under this time constraint. Therefore, it can give the industry a longterm trajectory that promotes energy efficiency and environmental clean-up. In other 

words, NHTSA has neither the legal mandate nor the ability to take a long-term view of 

fuel economy, but EPA has the ability to do so for tailpipe emissions. [OAR-2009-0472-

7272.1, pp.35-36] 

University of California, Los Angeles School of Law 

As you work to finalize the proposed federal greenhouse gas emissions standards 

referenced above, I write to urge you to resist any efforts restricting the right of 

California, after 2016 and under the Clean Air Act, to regulate automobile emissions 

more strictly than the federal government. [OAR-2009-0472-7263.1, p. 1] 

For over 40 years, California has had the authority to set stricter standards than the 

federal government for automobile emissions under the Clean Air Act. For thirty years, 

other states have been permitted to adopt those tougher standards. The program has 

worked exceedingly well, with California’s regulations often serving (as here) as a model 

for other states and even for national programs by showing what is possible. [OAR-2009-

0472-7263.1, p. 1] 

The tradition of state innovation benefits the country as a whole. When the Clean Air Act 

was passed, California had already begun, by necessity, to regulate motor vehicle 

emissions in significant ways. Congress wisely allowed California's program to remain 

and allowed other states to adopt California's regulatory program. Over time, California 

3-14
EPA CO2 Standards 

has shown an ability and willingness to regulate creatively in the public interest in ways 

that often lead to innovative solutions. This very federal rulemaking would not have been 

possible without the leadership of the states, and it should not be used as a means to 

restrict states’ abilities to continue to serve as leaders in the future. [OAR-2009-0472-

7263.1, pp. 1-2] 

Indeed, the national agreement paving the way for these regulations, signed onto by car 

manufacturers, states, and federal agencies, explicitly affirms “that the proposed national 

program would not alter California’s longstanding authority under the Clean Air Act to 

have its own motor vehicle emissions program.” [OAR-2009-0472-7263.1, p. 2] 

It is especially important to continue to allow California, post-2016, to address the threat 

posed by emissions of greenhouse gases from cars. In part because of a strong history of 

energy conservation in the state, motor vehicles are California’s largest source of 

greenhouse gas emissions and it will be difficult for the state to meet its GHG reduction 

requirements, enshrined in laws like California’s Global Warming Solutions Act, without 

maintaining flexibility in dealing with passenger vehicle GHG emissions. California’s 

greenhouse gas laws themselves have served as models for the nation, and many are 

looking to California’s implementation of these laws as indicators of the potential success 

of GHG emission reduction programs more generally. For this reason as well, it would be 

a serious error for EPA to tie California’s hands in regulating its most significant source 

of GHG emissions going forward. [OAR-2009-0472-7263.1, p. 2] 

State of New Jersey 

These reductions are critical [These comments were submitted as testimony at the New 

York public hearing. See docket number EPA-HQ-OAR-2009-0472-4621, pp. 113.] for 

the state to achieve its 2020 and 2050 greenhouse gas goals. Future federal programs 

should not preempt the states from establishing appropriate greenhouse gas emission 

reduction programs, including additional motor vehicle programs as they are provided for 

by federal law. [These comments were submitted as testimony at the New York public 

hearing. See docket number EPA-HQ-OAR-2009-0472-4621, p. 114.] 

Several other northeastern states who like New Jersey have already adopted and 

implemented the low emission vehicle program, as well as California, we've heard from 

NESCAUM and NACAA earlier today, we support their comments of the states and the 

regional groups and will highlight issues covered in their testimony in our written 

comments. [These comments were submitted as testimony at the New York public 

hearing. See docket number EPA-HQ-OAR-2009-0472-4621, p. 114.] 

State of Washington Department of Ecology 

The importance of preserving the Clean Air Act provision of state's rights to adopt motor 

vehicle standards - for California under Section 209 and for other states under Section 

177 - cannot be overstated. The Federal Clean Air Act generally prohibits states from 

adopting new motor vehicle emission standards. However, Congress specifically 

3-15 
EPA Response to Comments 

authorized California to establish its own emission standards for cars. Courts upheld this 

approach: 

Congress intended California to continue and expand its pioneering efforts at adopting 

and enforcing motor vehicle emission standards different from and in large measure more 

advanced than the corresponding federal program. [OAR-2009-0472-7299, p.1] Motor & 

Equipment Mfrs. Ass'n v. EPA ('MEMA I'), 627 F 2d 1095, 110-11 (D.C. Cir. 1979). 

[OAR-2009-0472-7299, p.2] 

According to the National Academies' National Research Council, California has used its 

authority as Congress intended, by implementing more aggressive measures than the rest 

of the country and serving as a laboratory for technological innovation. California's 

action paved the way for other states across the country to exercise their statutory 

authority under Section 177 of the Clean Air Act; 14 other states have adopted 

California's standards. As one of the first states to follow California's lead, Washington 

adopted California's GHG regulations on May 6, 2005. [OAR-2009-0472-7299, p.2] 

The federal government has been a follower, not a leader, in vehicle emissions 

improvements. [OAR-2009-0472-7299, p.2] 

California's statutory right to adopt more rigorous motor vehicle standards than the 

federal governments, and other states' rights to opt in to California's programs, must be 

acknowledged as the catalyst for this national vehicle GHG emissions reduction program. 

[OAR-2009-0472-7299, p.2] 

EPA should join state and local clean air agencies as an active proponent for the full 

preservation of these states' rights. [OAR-2009-0472-7299, p.2] 

Environment New Jersey 

For most of this decade, you know, unfortunately, we've had to look to the states on clean 

car legislation, clean car advocacy. Now it's time as we grapple with this crisis finally to 

give the green light to clean cars on the national level and nowhere is that more 

appreciated than in states like New Jersey and the other states which Steve [Steve Flint of 

the Mobil Sources and Fuels Committee of the National Association of Clean Air 

Agencies (NACAA) EPA-HQ-OAR-2009-0472-4621, p.53-65] mentioned and that have 

become leaders on this issue. We believe firmly in the adage from Supreme Court Justice 

Louis Brandeis, the states are the laboratories of democracy, and I believe that was 

especially proven from the advocacy work over the course of this decade. [EPA-HQOAR-2009-0472-4621, p.67] 

Second, specifically on the rule proposal, that it's a first strong step but must be 

strengthened to meet President Obama's proposals. [EPA-HQ-OAR-2009-0472-4621, 

p.68] 

3-16
EPA CO2 Standards 

And then finally I want to point out the proposal is certainly strong evidence that the 

Clean Air Act is effective in addressing global warming pollution. California has 

obviously been the leader on adopting emission standards than are stronger than the 

federal regulations, and they have led the way, but they have allowed states like New 

Jersey that have similar needs and similar air pollution problems to opt in to those 

programs. We believe firmly as I stated before that states should have that right, states are 

the laboratories of democracy. We certainly encourage that provision to remain. [EPAHQ-OAR-2009-0472-4621, p.77] 

EPA Response:

As described in Section III.D.1 of the preamble to the final rule, EPA and NHTSA have 

worked extensively with the state of California and other states which have adopted the 

California GHG emission standards, as well as many other stakeholders, to craft 

a national fuel economy and GHG emission program which allows manufacturers to 

build a single national fleet that will comply with EPA’s GHG and NHTSA’s CAFE 

standards, and avoids the situation where manufacturers' sales must comply with 

different standards in individual states, each with their own sales mix, etc. We believe 

that we have succeeded in this task. . 

EPA’s final rule does not change California’s authority to establish GHG standards for 

MY 2017 and beyond and to request a waiver of preemption under section 209 of the 

Clean Air Act for such standards, nor other states from adopting California standards 

which receive such a waiver. 

Regarding the interaction between the NHTSA fuel economy standards and the EPA 

GHG standards, there are two reasons why EPA projects greater GHG benefits and fuel 

savings for its standards. One reason, as cited by the State of Massachusetts in Section 

3.0, is the inclusion of reductions in GHG emissions from the air conditioning units 

present on motor vehicles. Credits for GHG improvements in air conditioning leakage 

and air conditioning efficiency are not considered under CAFE because they are not 

measured by the test procedures used (and for passenger automobiles, mandated) to 

measure fuel economy. Certain measures available under the CAFE program which have 

the effect of reducing fuel economy (and increasing GHG emissions), such as the use of 

automatic FFV credits through MY2020 and the option of paying fines in lieu of 

compliance, are either not being allowed or are impermissible under the Clean Air Act 

and the GHG rules. The difference in expected GHG reductions and fuel savings from 

EPA’s GHG standards and NHTSA’s CAFE standards can be seen in Tables I.C.1-2 and 

I.C.2-1 of the preamble to the final rule. 

NADA commented (cited in Section 3.0 above) that NHTSA fuel economy standards 

should be used to regulate CO2 emissions from the tailpipe as measured over the two 

cycle test procedure and EPA should only establish supplemental standards to address air 

conditioning related emissions. EPA disagrees with this approach for several reasons. 

One, the NHTSA fuel economy standards appropriately focus on the conservation of fuel 

consumption by the nation, which has many benefits beyond GHG emission control. As 

3-17 
EPA Response to Comments 

such, the CAFE standards do not distinguish between the carbon intensity of various 

fuels. For example, vehicles fueled with gasoline and diesel fuel can have the same fuel 

economy, yet have different CO2 emissions. Thus, it is appropriate for the CAFE 

program to focus on the volume of petroleum-based fuel consumed in each case, while 

also appropriate for EPA to distinguish between the two fuels due to their distinct carbon 

(and thus, tailpipe CO2 emissions) per gallon. Two, other GHGs are emitted from the 

tailpipe besides CO2, such as methane and nitrous oxide, which are not currently 

controlled by the CAFE program per EPCA and EISA. Three, the combination of twocycle tailpipe emissions and air conditioning-related emissions in one program 

provides manufacturers greater flexibility to select the most cost effective combination of 

control technology for their particular vehicles. This would not be possible with two 

separate programs due to the current inability of the CAFE program to accept increased 

air conditioning related controls in lieu of compliance with the CAFE standards 

(including the statutory prohibition on such consideration for passenger automobiles). 

Four, the Clean Air Act is more flexible with respect to test procedures. In 

particular, EPA may find it desirable in the future to expand the test procedures used 

to measure GHG emissions beyond the current FTP and HFET test cycles in order to 

obtain more realistic estimates of the benefits of GHG emission control technology. Fifth, 

the CAA is more flexible than EPCA with regard to providing compliance flexibilities, 

which may allow opportunities for more cost-effective regulatory approaches for GHG 

reductions. Finally, the commitment by California to accept compliance with federal 

standards for purposes of its state GHG program is premised on issuance of EPA GHG 

standards as described in the Joint Notice of Intent, and compliance by the automobile 

manufacturers with EPA’s GHG standards. Compliance with NHTSA CAFE standards 

for just these 5 model years would not lead to this result, nor would compliance with the 

much more limited GHG standards suggested by NADA. This would lead to the loss of 

this important benefit of a national program. EPA believes that these reasons amply 

justify the inclusion of CO2 emissions as measured over the current two cycle test 

procedure in its final GHG standards. 

In the example above given by AAM, a manufacturer generating a greater level of direct 

(i.e., refrigerant emission related) air conditioning emission credit relative to EPA's 

projection would be able to use this “extra” credit to reduce the requisite degree of CO2 

emission control over the two-cycle test procedure under the EPA program, but not under 

the NHTSA program. AAM recommends that the stringency of the CAFE standards be 

relaxed so that this situation could never occur. 

As mentioned above, although as a practical matter, the means of achieving requirements 

of the CAFE and GHG programs overlap to a large degree, they in fact have two distinct 

purposes. One focuses on fuel consumption, while the other focuses on GHG emissions. 

Because of these distinct goals, it is perfectly reasonable for a manufacturer to continue 

to have to reduce the fuel consumption of its fleet despite implementing non-fuel related 

GHG emission controls at a greater rate than projected by EPA. In any case, that is an 

issue of how to set the CAFE standard under EPCA, which is under NHTSA’s authority, 

and not how to set the GHG standard under the CAA. 

3-18
EPA CO2 Standards 

That said, the two agencies have attempted to craft their final standards in such a way as 

to ensure that the additional stringency of one program relative to the other results in 

valuable benefits to the nation, either in terms of fuel conservation or GHG emission 

reduction. Any over-compliance with NHTSA's fuel economy standard would clearly be 

applicable to compliance with EPA GHG standards. In contrast, a manufacturer which 

implemented more than our projected level of air conditioning controls in the early years 

of the program would still be required to comply with NHTSA's fuel economy standards. 

This is essentially the issue raised by NADA in Section 3.0 above and by AAM and VW 

in this section. EPA acknowledges that some manufacturers could choose to generate 

more A/C credits than what we estimated in the rule for MY 2012-2015. However, the 

agency believes that the differences will be small for the fleet as a whole. The agency 

does not feel that this will cause any disharmony or inconsistency between the EPA and 

NHTSA programs, or devalue such credits, as manufacturers can bank any 

overcompliance credits for the next model year (or beyond). The compliance situation 

for the next model year may be quite different depending on that company’s compliance 

burden and the ramp up rate of its standards (both CAFE and GHG). Therefore, EPA 

disagrees with the Alliance comment that the standards are structured in a way that can 

discourage A/C improvements. The EPA has every reason to believe that all 

manufacturers will take advantage of these cost effective technologies to reduce GHG 

emissions from light-duty vehicles. 

We disagree with NADA that this rule will have a negative impact on automotive 

dealerships. The two agencies appreciate the economic difficulties currently faced by 

many automobile dealerships and the fact that many have or could soon be forced to 

close. However, we believe that this is due to the current national and global economic 

downturn and the resulting decrease in vehicle sales and financial difficulties of several 

automotive manufacturers. The analysis supporting this rule clearly indicates that the 

fuel savings resulting from meeting the final standards far exceed the cost of the 

technology needed to achieve the standards. These costs include the costs of maintaining 

vehicle performance, utility, safety, and other characteristics, so that vehicles should be 

as acceptable to consumers as current models. (EPA did this by building technology 

packages for each vehicle type (see Chapter 1 of EPA’s RIA) that maintained the key 

performance characteristic. Each subsequent package generally costs more, provides 

greater fuel efficiency, and maintains performance relative to the package before it and, 

hence, the baseline or current vehicle.) Moreover, our analyses also reasonably project 

increased vehicle sales, and do not project that the rule will be the cause of any loss of 

sales. This calculation was done assuming that consumers consider only five years of 

fuel savings when buying vehicles, an assumption endorsed by NADA. That, coupled 

with the avoidance of the cited "patchwork" of state standards is expected to avoid any 

negative impact on automotive sales. 

The analysis in section 3.1 of the RIA describes how the EPA 250 g/mi CO2 equivalent 

fleetwide standard for 2016 achieves the level of control which would have been 

achieved by the California GHG standards in the State of California. However, that 

equivalency is not the basis for our selection of this level of control for the final EPA 

GHG standards, and we thus cannot accept the comment by NADA cited in Section 3.0. 

3-19 
EPA Response to Comments 

See section III.D (and in particular III.D. 6) of the preamble to the final rule which 

discusses the basis for the GHG standards and their feasibility. The basis for the final 

standards is a balance of the technical feasibility of the standards, the cost of this 

technology and the lead time needed to implement it, considerations of costs to 

consumers, the cost-effectiveness of needed technology, and the benefits which will 

accrue from the standards (among other factors), as described particularly in section III.D 

of the preamble to the final rule. Although the level of the California standards, and the 

technical analysis underlying those standards, was a reasonable starting point for 

evaluating a national GHG standard, the California standards are not the justification for 

the federal standards. See section III.D.1 of the preamble to the final rule. Achieving 

some degree of equivalence with the benefits of the California standards was an 

important aspect of obtaining cooperation from the state of California and the other states 

which had adopted California's standards to accept compliance with the EPA standards as 

compliance with their own standards. However, the standards reflect consideration of the 

relevant factors under section 202 (a) (1) and are justified on that basis. 

With respect to the comment that the EPA GHG standards for motor vehicles will be 

detrimental under a broader cap and trade regulation, this issue is currently not ripe as no 

such cap and trade program exists; nor has one been proposed by the agency. EPA will 

carefully consider the interaction between the final motor vehicle GHG standards and any 

future cap and trade program if and when a national cap and trade program exists. 

With respect to IPI's recommendation that EPA establish a broad regulation covering all 

mobile source GHG emissions, EPA is taking this initial action with respect to 

automobiles alone due to the impending timing of both California GHG standards and 

NHTSA CAFE standards. It is highly desirable that national GHG standards be 

coordinated with these other actions now versus the necessarily later date when more 

comprehensive regulations covering additional mobile sources could be established. 

EPA is currently working on GHG emission controls from other mobile sources, again in 

coordination with NHTSA fuel economy regulation as appropriate. We will take IPI's 

recommendations under consideration as the extent of GHG emission control from 

mobile sources expands. See State of Massachusetts v. EPA, 549 U.S. at 533 (EPA 

retains significant discretion as to timing of regulation). 

We do not understand the purported distinction being made by VW regarding the 

methodologies used to determine the fleet average fuel economy and GHG emissions 

under the two programs. The harmonic averaging of fuel economy essentially means the 

simple sales-weighted averaging of fuel consumption per mile. As fuel consumption per 

mile is proportional to CO2 emissions per mile for a given fuel, the two programs 

perform their sales-weighting consistently. There exist several statutory restrictions on 

the trading of car and truck credits under the CAFE program which cannot be avoided. 

EPA chose not to impose those restrictions, as it is not required by law to do so. This 

simply makes compliance with the EPA GHG standards somewhat more flexible. 

However, the analyses conducted by NHTSA demonstrate that the CAFE standards are 

feasible for the vast majority of sales under the final provisions of that program. In fact, 

VW is one of the manufacturers which has historically paid CAFE fines in lieu of 

3-20
EPA CO2 Standards 

compliance. EPA analyses indicate that VW may need to utilize more advanced 

technology on a greater percentage of its sales than most manufacturers in order to 

comply with the two programs. EPA analyses indicate that this is at least partly due to 

the fact that VW vehicles are heavier than other vehicles in their size classes. See Fig. 

III-D.6-1 and surrounding text in the preamble to the final rule. VW has not provided 

any information to demonstrate why this needs to be the case currently or in the future. 

VW has also not provided any information indicating that they are unable to implement 

for their U.S. sales volumes the types of advanced technologies which are already 

commercially available. 

EPA recognizes that several analyses have indicated that new vehicle purchasers do not 

always choose technology which pays for itself in terms of fuel savings. See chapter 

8.1.2 of the RIA and section III.H.1 to the preamble to the final rule. There are several 

possible reasons for this, but no consensus exists concerning the actual cause. We will 

continue to study this issue, along with others in the scientific and economic community. 

We believe that the implementation of the types of fuel savings and emission control 

technology projected in the analyses supporting these rules will provide direct consumer 

benefits far exceeding their cost, as well as important emission reduction related benefits 

for the national and global communities. 

3.2 Form of the standards 

Organization: Mercedes-Benz (Daimler AG) 

 International Council on Clean Transportation 

 European Small Volume Car Manufacturers' Alliance (ESCA) 

Comment:

Mercedes-Benz (Daimler AG) 

By choosing footprint as the attribute to apply in the joint rulemaking, the agencies have, 

indeed, created a mechanism for encouraging weight reduction in light trucks while 

maintaining vehicle size and functionality. The safety of the light truck fleet is enhanced 

by encouraging light trucks with lower centers of gravity, thereby reducing rollover risks. 

Functionality is maintained even as weight is reduced because the footprint system 

encourages lightweight materials. While traditionally changes in mass and size have been 

directionally consistent from a compatibility standpoint, with the advent of crash 

avoidance systems, expansion of crash energy distribution techniques and continued 

improvement in behavioral safety, smaller vehicles with advanced emissions controls can 

be safely incorporated into the current vehicle mix. 

That the relative stringency of the passenger car and light truck fleet has been quite 

stable, moreover, does not appear to reflect a policy determination as much as the fact 

that the standards for many years remained either frozen or moved in increments which 

would not have had a significant impact on the relative apportionment of the standards. 

The passenger car standard has remained at 27.5 mpg since 1990, and the light truck 

3-21 
EPA Response to Comments 

standard remained at 20.7 from 1996 through 2004, when NHTSA began to increase it 

incrementally. When NHTSA set new standards for MY 2011, the agency readjusted the 

curves to account for its decision to reclassify 2wd SUVs and crossovers as passenger 

cars and thus retained the traditional relative apportionment. See 74 Fed. Reg. 14196 

(March 30, 2009). NHTSA did not, however, consider the relative apportionment of 

stringency as between light trucks and passenger cars as a matter of policy. 

This rulemaking represents the first opportunity for the agencies to consider the 

comprehensive policy objectives of the joint proposal while establishing standards for 

passenger cars and light trucks. The agencies can achieve this objective, and promulgate 

a final rule that is in fact “as substantially described in the May, 2009 Notice of Intent to 

conduct rulemaking,” by setting the stringency of the passenger car standards for the 

model years leading up to MY 2016 according to a “generally linear phase-in.” Doing so 

would also be consistent with the goal of the rulemaking to adjust the fleet mix to 

improve emissions and fuel economy performance without affecting safety. [OAR-2009-

0472-7193.2, p.2-4] 

International Council on Clean Transportation (ICCT) 

We commend EPA and NHTSA for proposing a footprint-based adjustment to the CAFE 

standards instead of weight-based adjustments. Footprint-based adjustments fully 

encourage manufacturers to introduce lightweight materials, which can improve vehicle 

efficiency by 20% or more in the long run. Lightweight materials also extend the electric 

drive range of electric and plug-in vehicles by a similar amount. This is one area of 

policymaking where the U.S. is ahead of the rest of the world. Japan, Europe, and China 

have all adopted standards with weight-based adjustments that effectively discourage the 

use of lightweight materials. NHTSA pioneered the footprint concept with the 2011 light 

truck rule and we urge EPA and NHTSA to continue its use in the future. 

We also support the proposed change to the shape of the footprint adjustments. The linear 

slope for all but the largest and smallest vehicles provides a consistent signal to improve 

efficiency for all vehicles within this range, while the flat line for largest vehicles creates 

an incentive to make the largest vehicles smaller. 

The proposed rule maintains separate footprint curves for cars and light trucks. This 

subjects light trucks with the same footprint to much less stringent standards and gives 

manufacturers a tremendous incentive to reclassify cars as light trucks. In the past this 

has brought us such notable trucks as the Subaru Outback, Chrysler PT Cruiser, Dodge 

Magnum, Mazda 5, Chevrolet HHR, Porsche Cayenne, and BMW X6, which BMW 

describes as a Sports Activity Coupe. In the future it is likely to cause manufacturers to 

drop many 2wd versions of their small SUVs and make less efficient 4wd versions 

standard, so that they can be classified as light trucks instead of cars. This will actually 

increase overall real world fuel consumption and CO2 emissions in two ways. First, it 

will increase 4wd installation and directly increase the fuel consumption of the fleet. 

Second, it makes it easier for manufacturers to meet the standards, so that they do not 

have to implement as much technology on other vehicles. 

3-22
EPA CO2 Standards 

The large majority of light trucks today are based on car platforms with unibody 

construction. All minivans use unibody construction and cab-and-chassis construction for 

SUVs is rapidly disappearing. Except for pickup trucks and a few relatively low volume 

SUVs, such as the Jeep Wrangler and the Suburban, in the 2016 timeframe of the rule all 

light trucks will be based on car platforms. In addition, due to the empty pickup bed, 

pickup trucks are considerable lighter than truck-based SUVs with the same footprint and 

fit much better on a single footprint line. Thus, there is no technical reason to maintain 

separate footprint lines for cars and light trucks. 

EPA recognized the importance of this issue when it established a single Tier 2 emission 

standard for all cars and light trucks. The issue here is just as important. It is time to also 

end this artificial distinction between cars and light trucks for fuel efficiency and 

greenhouse gas emissions. A single footprint function will still give larger trucks a less 

stringent target to meet, while avoiding vehicle classification games and helping to 

ensure fuel consumption and GHG emission goals are actually met. 

[OAR-2009-0472-7156.1, pp.2-3] 

Organization: Toyota Motor North America 

EPA also requests comments on combining the entire fleet into a single compliance 

category, with a single target curve for the fleet each model year. If faced with just one 

federal program with which to comply, Toyota may not object to a combined fleet 

standard, since it would arguably provide manufacturer's with the greatest level of 

flexibility to comply and it would remove any concerns about vehicle classifications . 

However, due to the lack of harmonization with NHTSA's program that would result, and 

the inflexibility afforded NHTSA in the existing CAFE statute, Toyota would not support 

EPA setting a single target curve for the entire fleet of cars and trucks even though it 

would result in the greatest level of flexibility. [OAR-2009-0472-7291, p.7]EPA 

EPA Response:

EPA appreciates the comments concerning the relative stringencies of the NHTSA CAFE 

standards for cars and light trucks prior to MY 2012. There is no need to evaluate or to 

respond to these comments, however, as they are not germane to the EPA standards being 

proposed for 2012 and beyond. 

EPA also understands ICCT’s concern that manufacturers may have an incentive to 

convert two-wheel drive (2WD) vehicles SUVs to all-wheel drive (AWD) or four-wheel 

drive (4WD) in order to have these vehicles classified as trucks instead of cars, and thus 

reduce their applicable corporate fuel economy standard and increase their applicable 

corporate GHG standard. NHTSA modified its definition of trucks in its rule 

implementing the MY 2011 CAFE standards in order to counter manufacturers' actions 

which shifted vehicles with many car-like designs to the truck fleet. On the one hand , 

since the vast majority of the SUVs newly classified as cars are also available in AWD or 

4WD versions, manufacturers face few if any redesign hurdles in shifting these vehicles 

3-23 
EPA Response to Comments 

back to the truck fleet by emphasizing AWD or 4WD sales through sales incentives or by 

simply offering these vehicles in only AWD or 4WD versions. On the other hand, AWD 

or 4WD vehicles cost more to produce than 2WD versions and usually have lower fuel 

economy and higher CO2 emissions (though to a much lesser degree than the difference 

between the car and truck standard curves). Thus many consumers still may not desire to 

purchase 4WD vehicles because of concerns about cost premium and additional 

maintenance requirements; conversely, many manufacturers often require the 2WD 

option to satisfy demand for base vehicle models. The agencies note that many luxury 

SUVs are only offered with AWD or 4WD functionality, so vehicle purchasers appear to 

value these options. EPA will monitor this situation and assess the degree to which 

manufacturers attempt to relax the stringency of their applicable fuel economy and GHG 

standards by shifting sales of 2WD SUVs from their car fleets to their truck fleets. 

Should this occur, the agencies will evaluate further changes to the definition of cars and 

light trucks, as well as the relative stringency of their respective standards to address this 

situation in the future. 

Regarding the comment that the agencies should move towards single footprint-based 

standards for both cars and trucks, NHTSA addresses this issue with respect to the CAFE 

standards in section IV of the preamble to the final rule. Regarding the GHG standards, 

EPA believes that it is appropriate for the 2012-2016 MY period to utilize 

NHTSA's definition of cars and trucks to maximize consistency between the two sets of 

standards. For the purpose of this rule, the levels of the car and truck GHG curves are 

closely connected to the 2011 NHTSA definitions of cars and trucks. Were EPA to either 

utilize a different set of vehicle definitions or establish a single standard curve, 

the overall level of GHG control would be roughly the same given the same level of 

technology application. However, the impacts on specific manufacturers of doing so 

would be very large in some instances. EPA believes that more leadtime should be 

available before such dramatic changes to the relative stringency of the GHG standards 

across manufacturers should be effected. 

EPA notes that the incremental cost for a larger light truck to achieve the Tier 2 emission 

standards relative to that for a car is much smaller than the incremental cost for a large 

truck to achieve the fuel economy or GHG emission level of a car. In part that is because 

tailpipe emissions of the criteria pollutants are largely driven by the after treatment 

catalyst and related technology, while the factors that affect GHG emissions are much 

more varied and involve a much wider variety of systems in the vehicle. This leads to 

larger differences between vehicles as far as baseline technology that impacts GHG levels 

and GHG controls. Thus, while the equivalent treatment of cars and trucks in EPA's Tier 

2 emission control program is an appropriate analogy with respect to this GHG program, 

the technology and economic implications are much greater and we believe that further 

study would be necessary to justify such large relative economic impacts across 

manufacturers. 

3.2.1 Choice of footprint as the attribute and international harmonization 

3-24
EPA CO2 Standards 

Organization:General Motors 

Ferrari S.p.a 

Toyota Motor North America 

Northeast States for Coordinated Air Use Management 

BMW of North America, LLC (BMW) 

Lawrence Berkeley National Laboratory 

SABIC Innovative Plastic 

International Council on Clean Transportation 

National Automobile Dealers Association (NADA) 

Lotus Cars Ltd. 

Cummins Inc. 

Porsche Cars North America, Inc. 

Fisker Automotive, Inc. 

European Automobile Manufacturer's Association 

New York State Department of Environmental Conservation 

Ecology Center 

Bright Automotive 

Johnson, Kenneth C. 

Comment:

General Motors 

Among the highlights of the proposal is the coordinated attribute-based approach of the 

two programs. [OAR-2009-0472-6185, p.11] 

GM especially supports: 1) the coordinated attribute based approach of the two 

harmonized programs; and 2) the recognition of the need for mechanisms to provide for 

compliance flexibility in the face of great uncertainty over future technology 

developments and costs, customer acceptance of these technologies, and the price of fuels 

that consumers may see in the marketplace. All of these factors make it critical that 

automakers have some ability to cope with changes or unexpected outcomes, and we 

believe the proposed rules provide essential flexibility. [OAR-2009-0472-6953.1, p.2] 

Ferrari S.p.a 

Ferrari concurs with EPA and NHTSA that the method to classify vehicles should be as 

simple as possible, and based on reliable and stable attributes. Moreover, we support the 

harmonization of the EPA and NHTSA rules in the National Program. Nonetheless, we 

are concerned that the footprint alone does not take into account many of a vehicles’ 

other characteristics that greatly affect the fuel economy. For example characteristics like 

the engine, transmission, curb weight, aerodynamics, etc. We treat this topic with more 

details in the comments to the proposed NHTSA CAFE rule. We support the adoption of 

a constrained linear rather than a constrained logistic function. We think it is not 

necessary to put a “backstop” for both CO2 and CAFE standards. [OAR-2009-0472-

7214.1, p.3] 

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EPA Response to Comments 

Toyota Motor North America

EPA requests comments on its proposal to use a footprint-based attribute approach for 

regulating GHG emissions. Toyota supports EPA's selection of footprint, subject to the 

additional comments below regarding Emissions Covered. Toyota supports 

harmonization of the EPA and NHTSA programs to the greatest extent practicable. Since 

NHTSA has already established footprint as the attribute upon which the CAFE program 

is based, and they have continued use of footprint in the subject proposal, Toyota agrees 

with EPA's selection of footprint as the attribute for its program. This approach will result 

in harmonization of the two regulatory programs in terms of the attribute upon which the 

standards are based. [OAR-2009-0472-7291, p.6] 

Northeast States for Coordinated Air Use Management

NESCAUM concurs with and supports the EPA and DOT decision to use an attributebased standard rather than an industry-wide average standard. 

Footprint-based standard: NESCAUM agrees with EPA’s approach to regulate vehicle 

footprint. Consistent with the model year 2011 CAFE standards, EPA and DOT are 

proposing to use footprint as the attribute for the model year 2012-2016 CAFE standards 

and CO2 emissions standards. Footprint-based standards provide an incentive to use new 

and advanced lightweight materials and structures that could otherwise be discouraged by 

weight-based standards. Manufacturers can use them to improve a vehicle’s fuel 

economy without necessarily resulting in a change in the vehicle’s target level of fuel 

economy or CO2 emissions and without a substantial impact on the safety (in terms of 

crashworthiness) of that vehicle. 

EPA has crafted the proposal in a way that ensures consumers will continue to have the 

variety and choice in vehicle models they have come to expect. The size-based standard 

provides manufacturers with significant flexibility in meeting the proposed GHG 

reductions. Furthermore, as mentioned above, technologies to reduce vehicle GHG 

emissions exist in the market today. The phase-in of the standards between 2012 and 

2016 allows manufacturers six years to incorporate these technologies into greater 

numbers of vehicles. [OAR-2009-0472-7235.1, p.4] 

[Northeast States for Coordinated Air Use Management also submitted these comments 

as testimony at the New York public hearing, See docket number OAR-2009-0472-4621, 

p. 43.] 

BMW of North America, LLC (BMW) 

With respect to one national program. BMW fully supports an attribute-based program 

for passenger cars and light trucks as proposed by EPA and NHTSA. Compared to a 

uniform standard for passenger cars and light trucks, an attribute-based standard drives 

fuel efficiency and GHG reduction in all segments while taking into account the 

manufacturer's product portfolio. However, because BMW offers a worldwide product 

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EPA CO2 Standards 

portfolio and most of the C02 and fuel economy regulations worldwide are based on 

vehicle weight instead of footprint, BMW recommends that these regulations be 

harmonized as much as possible. [OAR-2009-0472-7145.1, pp.4-5] 

[BMW of North America also submitted these comments as testimony at the New York 

public hearing, See docket number EPA-HQ-OAR-2009-0472-4621, p. 133.] 

Lawrence Berkeley National Laboratory 

Comments are directed at the choice of vehicle footprint as the attribute by which to vary 

fuel economy and greenhouse gas emission standards, in the interest of protecting vehicle 

occupants from death or serious injury. Comments are summarized below: 

Analysis of casualty risk finds that, after accounting for drivers and crash location, there 

is a wide range in casualty risk for vehicles with the same weight or footprint. This 

suggests that reducing vehicle weight or footprint will not necessarily result in increased 

fatalities or serious injuries. 

Indeed, the recent safety record of crossover SUVs indicates that weight reduction in this 

class of vehicles resulted in a reduction in fatality risks. 

Computer crash simulations can pinpoint the effect of specific design changes on vehicle 

safety; these analyses are preferable to regression analyses, which rely on historical 

vehicle designs, and cannot fully isolate the effect of specific design changes, such as 

weight reduction, on crash outcomes. 

There is evidence that automakers planned to build more large light trucks in response to 

the footprint-based light truck CAFE standards. Such an increase in the number of large 

light trucks on the road may decrease, rather than increase, overall safety. [NHTSA2009-0059-0060.1, p.1] 

See all the casualty analysis related to vehicle footprint in pp.2-11 of the docket. 

SABIC Innovative Plastic

SABIC-IP supports the footprint-based regulatory program proposed because it 

encourages both appropriate materials substitution on existing products and the 

development of a safe, lighter-weight vehicle fleet. [OAR-2009-0472-7080.1, p.2] 

International Council on Clean Transportation 

[[These comments were submitted as testimony at the Detroit public hearing. See docket 

number EPA-HQ-OAR-2009-0472-6185, p. 58.]] 

We commend EPA and NHTSA for proposing a footprint based adjustment to the CAFE 

standards instead of weight based adjustments. Footprint based adjustments fully 

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EPA Response to Comments 

encourage manufacturers to introduce lightweight materials, which can improve vehicle 

efficiency by 20 percent or more in the long run. Lightweight materials also extend the 

electric drive range of electric and plug-in vehicles by a similar amount. 

This is one area where the U.S. is ahead of the rest of the world. Japan, Europe, and 

China have all adopted standards with weight-based adjustments that discourage the use 

of lightweight materials. NHTSA pioneered the footprint concept with the 2011 Light 

Truck Rule, and we urge EPA and NHTSA to continue its use in the future. 

National Automobile Dealers Association (NADA) 

The proposal’s vehicle attribute-based framework is essential to driving fuel economy 

performance improvements while allowing dealers to access a mix of cars and trucks that 

meet their customer needs. As recognized by EISA, attribute-based standards offer at 

least four critical benefits over “flat” standards. First, greater fuel economy and GHG 

emission benefits can be expected as continuous improvements are encouraged across all 

vehicle types, regardless of product mix. Second, if set correctly, an incentive to the 

inexpensive downsizing or downweighting of vehicles is eliminated, helping to preserve 

passenger safety. Third, an attribute based approach inherently is more equitable in that it 

is largely product plan neutral, acting to spread compliance costs broadly across all 

regulated vehicle manufacturers. Finally, and perhaps most importantly, by avoiding 

mandated fleet mixes, an attribute-based approach recognizes and capitalizes on the 

critical consumer choice factors that drive a successful fuel economy/GHG improvement 

program. As stated above, hoped-for fuel economy and GHG benefits simply will not be 

realized until consumers purchase and use the regulated vehicles in question. [OAR2009-0472-7182.1, p.4] 

The National Program proposal’s standards are based on a footprint (average track width 

times average wheelbase) attribute and a continuous function (vs. step function) curve 

similar to that first used in the 2006 light truck CAFE rule. Appropriate dispensation 

must be allowed to help ensure the final National Program does not frustrate customer 

demand for new light trucks as their maximum towing, cargo-hauling, and four-wheel 

drive (4WD)/all-wheel drive (AWD) capabilities are essential to certain vocational and 

recreational demands. Business and consumer purchasers focused on vehicle utility and 

durability buy light trucks for their capability and performance characteristics and 4WD 

and AWD options are popular for off-road commercial and recreational use and for onroad handling benefits. Tow-capable configurations or “packages” are essential to many 

uses. Having a wide variety of vehicles available for use in trade or business particularly 

is essential to the small business community which drives the U.S. economy. Large and 

powerful light trucks are essential to many business purchasers (e.g., farmers, contractors, 

etc.), and larger vans and SUVs are often the first choice of growing families and 

carpoolers. The stringency of the light truck curve must not constrain the ability of 

vehicle manufacturers to meet these market needs, as it would leave the motoring public 

no choice but to keep older, less efficient vehicles longer or to turn to the used vehicle 

marketplace. [OAR-2009-0472-7182.1, pp.4-5] 

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EPA CO2 Standards 

The attribute-based, continuous curve framework is designed to foster real world fuel 

economy improvements and GHG reductions by maintaining consumer choice, by 

protecting safety, by distributing costs more equitably, and by reducing the overall cost of 

regulation. These same benefits also argue for downward sloping curves without any 

flattening at the lower asymptote. Any constant value or “clip” applied to the end of a 

curve could serve to severely limit the availability or performance of vehicles demanded 

by the motoring public, especially light trucks, effectively imposing an unwarranted 

“backstop” compliance overlay. [OAR-2009-0472-7182.1, p.5] 

Lotus Cars Ltd. 

The proposed legislation attempts to account for differing vehicle segments with sizebased standardization; however such an approach can only work together with fleet 

averaging if the fleet itself can be considered 'average'. The footprint of a vehicle does 

not differentiate to a sufficient degree between vehicle segments for this approach to 

work with small volume manufacturers. In practice, it is quite possible for a sports car to 

have the same footprint size as a compact saloon vehicle, which would result in the 

applicability of a similar greenhouse gas target. [OAR-2009-0472-7249, p.6] 

Cummins Inc. 

Cummins supports the attribute-based standards for setting CAFE and GHG standards; 

however, we urge EPA and NHTSA to consider a secondary attribute for light-duty 

trucks (with significant hauling and towing capacity as well as off road capabilities) for 

determining the target fuel economy/CO2 emissions. Trucks primarily used for work 

purposes (e.g. trucks equipped with diesel engines), are engineered for heavier use (more 

capable components) resulting in lower fuel economy than similar truck meant for lightload use. Cummins supports a proposal for creating a separate classification for heavytow, highly capable trucks which would provide a more equitable framework for vehicles 

meant for towing and cargo-hauling. The SAE J2807 recommended practice provides a 

robust framework to define a tow rating for vehicles and eliminates potential gaming, as 

noted by NHTSA in an earlier NPRM. [OAR-2009-0472-7205.1, p.4] 

Porsche Cars North America, Inc. 

Porsche's sport car average footprint (the basis for our target standards) is: 

• The smallest in the industry 

• 14% less than the industry average 

• considerably smaller than companies known for producing small cars (e.g., Honda, 

Toyota, Suzuki, etc.) 

Because the standards proposed are entirely based on footprint and because our footprint 

is the smallest, the proposed standards for Porsche are the most stringent. While we do 

3-29 
EPA Response to Comments 

not believe that it is the intent of EPA/DOT to make Porsche the world's most fuel 

efficient passenger car manufacturer or to punish Porsche, this is the consequence of the 

footprint-based concept. While there is a reasonable correlation between footprint and 

fuel economy and C02 for the average fleet of cars there are cars for which this does not 

apply. Sports cars, especially Porsche cars have a very short wheelbase for handling 

reasons in combination with high performance, which is an attribute associated with 

sports cars and a selling point. Unfortunately the standard in this footprint category is set 

by small, low priced sedans, a category where fuel economy is an important selling 

attribute rather than performance. 

In proposing to establish standards based entirely on vehicle footprint, EPA and DOT 

have proposed a set of standards that would perversely require Porsche (a company 

predominantly manufacturing high-powered sports cars) to become the fuel efficiency 

leader in the United States. 

In Figure 1 [OAR-2009-0472-7431.1, p.5] below, using the proposed standards shown in 

the tables above, we have plotted the percent improvement required for compliance for 

each manufacturer. We show the percent improvement required relative to 2008MY 

performance since this is the most recent model year for which complete fuel economy 

model year data was available at the time at which these comments were initially drafted. 

It should be understood that, according to the proposal, Porsche is expected to achieve a 

passenger car fuel economy level of 41.4 mpg (or 204 g/mi C02) by 2016MY. This is by 

far the highest mpg value demanded of any auto maker affected by the proposal. [OAR2009-0472-7431.1, pp.1-6] 

Fisker Automotive, Inc. 

Fisker Automotive recommends a flat standard to avoid irrational trends to certain 

vehicle sizes or types. That is, the standard’s emissions allowance should not correlate to 

footprint or separate passenger cars from lightduty trucks. The regulation, as proposed, 

appropriates more credits to larger vehicles and trucks, causing an economic incentive 

not only to increase fuel economy, but to increase vehicle footprint and to classify as a 

truck as well. The market should decide vehicle sizes and types. [OAR-2009-0472-

8732.1, p.5] 

Automakers have many options available to decrease emissions, including electrification, 

powertrain efficiency increase, weight reduction, and aerodynamic drag reduction, etc. 

Regulation should remain neutral to allow all methods of improvement. Averaging, 

banking, and trading methods are sufficient to maintain diverse consumer choice of 

vehicles. [OAR-2009-0472-8732.1, p.5] 

The Fisker Karma, for example, will do unusually well under the proposed footprint 

method because it has a very large footprint and superb fuel economy, well beyond 2016 

targets. If we chose to make a version of the Karma with a smaller footprint, it would 

actually do worse under the proposed regulation, even if the utility (e.g. seating, storage 

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EPA CO2 Standards 

space, and performance) and fuel economy remained exactly the same. This does not 

make sense. In a competitive market, automakers will be driven to sell larger vehicles and 

trucks for the increased credits. We would like the freedom to design our vehicles 

without concern for these footprint and classification metrics. [OAR-2009-0472-8732.1, 

pp.5-6] 

While larger vehicles can be made safer, this is not always the case. For example, many 

large SUVs are considerably more dangerous than smaller vehicles due to rollover 

concerns. NHTSA can (and does) implement safety regulations to directly address safety 

issues. We consider it best to handle safety in this manner, separately from emissions. A 

flat standard would remain neutral to size, as consumer demand will remain for large 

vehicles. Furthermore, hybrid and electric vehicles do not suffer in fuel economy from 

weight increase nearly as much as traditional vehicles due to their regenerative braking 

capability. This will also serve to maintain diverse consumer choice of vehicles. [OAR2009-0472-8732.1, p.6] 

Finally, causing a trend towards larger vehicle footprints can have adverse environmental 

affects. Material requirements would increase, and unless automakers take considerable 

effort to avoid it, environmental impact (e.g. CO2 emissions) of vehicle production 

would increase in step. The regulation should serve to put a market value only on metrics 

of concern to the regulation—GHGs and fuel. [OAR-2009-0472-8732.1, p.6] 

European Automobile Manufacturer's Association 

ACEA emphasizes that any legislation should in principle not be technology prescriptive. 

Also, efforts with a view to increasing international harmonization of motor vehicle 

regulations should be maintained where appropriate. [OAR-2009-0472-7444.1, p.1] 

New York State Department of Environmental Conservation

Use of Footprint as a Basis for Standards (Preamble Section III.B.2) 

EPA proposes an attribute based greenhouse gas standard, using vehicle footprint as the 

basis. NHTSA is required by statute to establish attribute based CAFE standards. The 

benefit of harmony between the CAFE and greenhouse gas standards outweighs any 

potential benefits an alternate form of greenhouse gas standard might have, and we 

believe that footprint is at least as valid as any other attribute. [OAR-2009-0472-7454, 

p.1] 

Ecology Center 

One key aspect of the proposed rules is the attribute-based system for determining fuel 

economy standards. This approach ensures that fuel-economy progress will be made 

across the broad spectrum of vehicle types and sizes, rather than just through downsizing 

or by certain manufacturers. In the past, the fleet average approach has tended to put fullline manufacturers with market share in the larger vehicle segments at a significant 

disadvantage. Now all manufacturers will share the burden of improving the fuel 

3-31 
EPA Response to Comments 

economy of their vehicles. The Ecology Center also believes that using the vehicle 

footprint attribute is the most preferable from an environmental and safety perspective to 

a weight-based approach. [OAR-2009-0472-4068, pp.1-2] 

Bright Automotive 

[These comments were submitted as testimony at the Los Angeles public hearing. See 

docket number EPA-HQ-OAR-2009-0472-7283, pp.173-179] 

I'd like to also applaud the footprint standard because, again, we do not want to force a 

single solution into downsized vehicles. We want to be able to allow our customers and 

Americans to drive vehicles in the size they want. 

That being said, lightweighting is an extremely important driver for electrification 

in meeting these standards and importantly for the safety concerns as well. There is a 

strong correlation between weight and size for safety, but there's even -- I'm sorry. 

Weight and safety. There's a stronger correlation between size and safety. 

So if you can decouple weight and size, what you can get are vehicles that are large 

like our 63-square-foot light truck that are safe and not just safe to the occupants but safe 

to other drivers and pedestrians. 

Johnson, Kenneth C. 

These comments are respectfully submitted in response to the following request, on page 

49685 of the Notice of Proposed Rulemaking (NPRM): 

... while NHTSA tentatively concludes that footprint is the most appropriate attribute 

upon which to base the proposed standards ... we seek comment on whether the agency 

should consider setting standards for the final rule based on another attribute or another 

combination of attributes. [OAR-2009-0472-7135.1, p.1] 

One of the key recommendations of the 2002 NAS Report was the following: 

Recommendation 3. Consideration should be given to designing and evaluating an 

approach with fuel economy targets that are dependent on vehicle attributes, such as 

vehicle weight, that inherently influence fuel use. Any such system should be designed to 

have minimal adverse safety consequences. (emphasis added) [OAR-2009-0472-

7135.1, p.1] 

The NPRM deviates from this recommendation by adopting a footprint attribute, which 

does not inherently influence fuel use. In contrast to weight, there is no clear causal 

connection between footprint and fuel economy, as evidenced by their poor correlation. 

[OAR-2009-0472-7135.1, p.1] 

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EPA CO2 Standards 

The poor correlation is clearly evident from the current fuel economy and footprint data 

provided in the NPRM, Tables IV.C.1–2 and IV.C.1–4a. This data is plotted in the 

attached Figure 1. (Each data point represents a particular manufacturer; and the X’s and 

O’s represent passenger cars and light trucks, respectively.) By contrast, weight is 

strongly correlated to fuel economy across all manufacturers and vehicle classes (Table 

IV.C.1–5a, attached Figure 2). Furthermore, the weight correlation is stronger than that of 

power-to-weight ratio, even though the latter is also causally related to fuel economy 

(Table IV.C.1–6a, attached Figure 3). [OAR-2009-0472-7135.1, pp.1-2] 

The policy rationale for favoring a footprint attribute over weight is based on the two 

competing objectives of discouraging weight-changing compliance strategies that would 

adversely impact safety or consumer choice, and also encouraging weight-changing 

strategies that would improve fuel economy without adversely affecting consumer 

welfare. The NPRM recognizes that the rulemaking does not effectively balance these 

objectives. As noted on pages 49462-49463, “... even under attribute-based standards, 

there is still risk that manufacturers will rely on downweighting to improve their fuel 

economy (for a given vehicle at a given footprint target) in ways that may reduce safety”. 

Furthermore (page 49725), “NHTSA cautions that vehicle footprint is not synonymous 

with vehicle size. Since the footprint is only that portion of the vehicle bounded by the 

front and rear axles and by the wheels, footprint based standards do not discourage 

downsizing the portions of a vehicle in front of the front axle and to the rear of the rear 

axle ... The crush space provided by those portions of a vehicle can make important 

contributions to managing crash energy.” [OAR-2009-0472-7135.1, p.2] 

The NPRM suggests that a weight-based standard would create perverse incentives to 

increase weight. As noted on page 49685, “it is relatively easy for a manufacturer to add 

enough weight to a vehicle to decrease its applicable fuel economy target.” However, it is 

not easy to add weight without also compromising fuel economy, and thereby nullifying 

the advantage of a less stringent target. A weight-based standard would, by design, 

neutralize – not increase – weight-changing incentives. It would nullify the large weightreduction incentive of an attribute-neutral standard, but would not reverse that incentive. 

[OAR-2009-0472-7135.1, p.2] 

The primary drawback of a weight-based standard is that it would create no incentive for 

beneficial weight-changing compliance strategies. But since the regulatory incentive 

would be substantially weight-indifferent, the standard would also not incentivize 

detrimental weight changes; and it would not conflict with complementary policies that 

are targeted specifically at creating favorable (e.g., safety-enhancing) weight-changing 

incentives. [OAR-2009-0472-7135.1, p.3] 

The proposed footprint attribute cannot optimally balance the tradeoff between favorable 

and unfavorable weight changes because it does not discriminate between the two. For 

example, the NPRM states on page 49685 that “footprint-based standards provide an 

incentive to use advanced lightweight materials and structures that would be discouraged 

by weight-based standards”. But the standards would not incentivize downweighting 

exclusively by such means. As stated on page 49727, “... weight can be removed by 

3-33 
EPA Response to Comments 

downsizing, rather than material substitution, even while maintaining footprint”. [OAR2009-0472-7135.1, p.3] 

How can the weight-change conundrum be resolved? The solution can be illustrated by 

analogy with a similar problem in the electricity industry. [OAR-2009-0472-7135.1, p.3] 

A power utility can reduce emissions by using cleaner energy-generation technology (i.e. 

reducing GHG emissions per generated kWh). It can also reduce emissions by investing 

in energy efficiency (i.e. reducing kWh consumption per unit of consumer utility). For 

example, it could finance or subsidize home weatherization programs, efficient lights and 

appliances, etc. But an emission performance standard based on GHG emissions per kWh 

would, in effect, award emission allowances in proportion to energy generation, and 

would therefore provide no incentive for reducing energy consumption. How can this 

problem be resolved? [OAR-2009-0472-7135.1, p.3] 

One approach would be to award emission allowances in relation to some kind of 

attribute, such as a generating facility’s “footprint,” which would somehow balance the 

competing incentives. But a more practical approach would be to simply recognize that 

promoting clean energy generation and energy efficiency are independent, separable 

problems that can be addressed with separate, complementary policies. A GHG-per-kWh 

performance standard could effectively induce clean energy generation, while a separate 

regulatory measure would be employed to promote energy efficiency. [OAR-2009-0472-

7135.1, p.3] 

Similarly, the vehicle regulation problem can be efficiently partitioned into two separate 

problems: one of minimizing emissions per unit weight, and one of minimizing weight 

per unit of consumer utility. Furthermore, safety could also be addressed as a separate 

regulatory problem – the regulations should not, in effect, use weight (or footprint) as a 

proxy for safety. Trying to solve all of these problems with one standard, as the NPRM 

proposal does, leads to regulations that are over-constrained and therefore 

suboptimal. [OAR-2009-0472-7135.1, p.4] 

The NPRM notes, on page 49724, that “The question of the effect of changes in vehicle 

weight on safety in the context of fuel economy is a complex question that poses serious 

analytic challenges ...,” but these complexities can be circumvented by using a weightbased standard that would, by design, create no significant weight-changing incentives. 

Instead, the “serious analytic challenges” would be localized in a separate, 

complementary regulatory measure, which would be specifically and exclusively targeted 

on motivating optimal weight-changing strategies. This measure, unlike the proposed 

footprint-based standard, would discriminate between strategies based on their consumerwelfare impacts; and it would preferentially and selectively focus incentives on beneficial 

strategies. [OAR-2009-0472-7135.1, p.4] 

In one approach, optimal weight reduction could be incentivized by a crediting system 

somewhat analogous to air conditioning credits. “Weight credits” would be awarded for 

the use of qualified engineering materials based on their equivalent utility characteristics. 

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EPA CO2 Standards 

For example, if a vehicle manufacturer replaces 1000 lbs of steel with 600 lbs of 

functionally equivalent, high-strength composite material, then the 400-lb difference 

would be added to the vehicle weight for the purpose of determining its compliance 

requirement under a weight-based standard. [OAR-2009-0472-7135.1, p.4] 

Safety concerns could similarly be addressed through regulatory measures that apply 

specifically to safety-related vehicle attributes. For example, vehicle safety regulations 

might specify a minimum vehicle footprint-to-weight ratio, or a maximum center-ofgravity height as a proportion of track width. [OAR-2009-0472-7135.1, p.4] 

A weight-based standard, complemented with optimal weight-reduction incentives and 

safety-related regulations, would achieve all of the objectives that the footprint-based 

standard is intended to achieve, but without the tradeoffs inherent in a one-size-fits-all 

regulatory approach. The benefits of this approach would include some or all of the 

following: (1) less disparity in manufacturers’ and consumers’ compliance costs, (2) 

improved economic feasibility (and consequently, potentially more stringent emission 

targets), (3) better preservation of consumer choice, and (4) enhanced safety. [OAR2009-0472-7135.1, p.4] 

The separate, but complementary, regulation of fuel economy and emissions by NHTSA 

and EPA argues in favor of a similar separation of weight-changing and safety 

regulations; and a weight-based standard would represent a step toward 

harmonized international standards. (China, Japan, and the European Union use weightbased standards.) Inasmuch as this approach has not been identified as a regulatory option 

in the NPRM and appears not to have been considered by the agencies, I encourage the 

agencies to do at least a cursory comparative analysis of this approach and to objectively 

consider its merits, and then to reevaluate the policy rational underlying NHTSA’s 

selection of footprint as “the most appropriate attribute upon which to base the proposed 

standards”. [OAR-2009-0472-7135.1, pp.4-5] 

EPA Response:

Most of the comments received on this issue support the use of footprint as the sole or at 

least one of the attributes upon which to base the fuel economy and GHG standards. 

Most of those disagreeing with the use of footprint support the substitution of vehicle 

weight for footprint for two primary reasons. One reason is harmonization with the fuel 

economy, fuel consumption, CO2, or GHG emission standards of other nations. The 

other is the fact that vehicle weight is a much better predictor of fuel economy and CO2 

emissions than footprint. Starting with international harmonization, EPA agrees that the 

use of vehicle weight as the primary attribute upon which to base the final standards 

would result in standards that, in that respect, appear to be more closely harmonized with 

the standards of several nations, namely Europe, Japan, and China. However, we believe 

that the benefits of this harmonization could be minimal, and in any event, do not 

outweigh the detriments at this time. 

3-35 
EPA Response to Comments 

First, establishing a weight based standard in the U.S. would not guarantee that the same 

vehicles could or would be sold in all of the nations with weight based standards 

presently; indeed, there is little, if any, evidence that weight-based fuel consumption and 

GHG emissions standards in place in Europe, Japan, and China are leading to 

significantly more similar new vehicle fleets in those regions. Even if the standard curve 

were the same in two or more nations, the mix of vehicles sold would likely vary across 

national boundaries. Manufacturers comply with their applicable sales-weighted standard 

by balancing the number of vehicles sold which are above and below the standard (and 

the degree to which they are above and below the standard, of course). Setting the 

appropriate level of a fuel economy or GHG standard depends on many factors, including 

fleet mix and other regulations (e.g., safety requirements, NOX and PM emissions 

standards). Fleet mix varies widely across national boundaries, and some other 

regulations are not as stringent in other countries as in the United States. Thus, it may 

not be appropriate for all nations to set the same level of fuel economy or GHG emission 

standard. In fact, harmonization of fuel economy or CO2 standards internationally is 

most practically achieved when roughly the same level of fuel conserving and CO2 

reducing technologies can be marketed internationally. The fact that many of 

technologies projected to be used to meet the final standards are already utilized 

commercially in Europe and Japan is an indication that the final standards are 

harmonized to some extent internationally. In addition, because the focus of EPA’s 

standards are GHG emissions and not fuel consumption, manufacturers have the option 

(and are expected to take advantage) of generating credits through the use of low leak 

A/C systems, which are not presently incorporated into other nations’ fuel conservation 

programs. 

Second, as mentioned by several commenters, setting a weight-based GHG standard 

eliminates the incentive for manufacturers to use weight saving materials or techniques to 

reduce fuel consumption and CO2 emissions. As one commenter points out, fuel 

consumption and CO2 emissions are highly correlated with weight. As described in the 

Joint TSD, there are numerous ways that vehicle weight could be reduced in the future 

while maintaining vehicle safety and utility. A weight based standard (where the slope 

was set to neither promote mass increases or decreases) would simply remove these 

techniques from consideration. 

The fact that vehicle weight correlates much better than footprint with fuel consumption 

and CO2 emissions is, however, not the most relevant factor when selecting the 

attribute to use when developing the standard curve. In its 2002 report on the CAFE 

program, NAS recommended that NHTSA adopt weight-based standards in order to 

discourage manufacturers from responding to CAFE standards by reducing vehicle mass 

in ways that would compromise highway safety. However, NHTSA has concluded and 

EPA agrees that a size-based system not only more equitably distributes compliance 

burdens than a flat standard, but also that, compared to a weight-based system, a sizebased system encourages further penetration of high-strength lightweight materials and, 

importantly, incurs less risk that energy and environmental benefits will be lost to 

“gaming” (it being much easier to increase a vehicle’s mass than to increase its footprint). 

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EPA CO2 Standards 

In another comment, Cummins recommends that towing capacity be added as a 

secondary attribute to the proposed truck category, as greater towing capacity increases 

vehicle utility in a manner similar to greater footprint. Cummins suggests that such 

vehicles be granted a numerically higher CO2 standard than other trucks. We believe 

that towing capacity is already implicitly factored into the proposed (and final) car and 

truck curves. Towing capacity tends to be higher for trucks than for cars and trucks are in 

fact allowed to emit more CO2 than cars (at a given footprint) under the final standard 

which was developed based on analysis of the agencies’ forecast of vehicle models 

expected to be present in the future light truck market. We also believe that larger trucks 

tend to have higher towing capacities than smaller trucks and again, larger trucks are 

allowed to emit more CO2 than smaller trucks, up to a footprint of 66 square feet. In 

other words, differences in towing capacity are part of the reason why the GHG standard 

curve increases with vehicle size and is higher for trucks than for cars. It is possible that 

EPA would consider adding additional attributes like towing capacity to its standard 

setting function in the future. 

Several manufacturers make a similar suggestion for engine size or power (or multiple 

attributes). Vehicles with higher engine power tend to have higher CO2 emissions due to 

the fact that the engines operate at lower average loads over the two-cycle test procedure. 

Unlike passenger and cargo capacity, however, the societal benefit of higher engine 

power is less clear. The analysis supporting this rule assumes no change in the 

acceleration performance of vehicles due to the rule (and the agencies’ cost analysis 

includes the costs for preserving acceleration performance). In other words, we have 

included performance vehicles in our analysis and we have evaluated the various GHG 

reducing technologies in such a way to maintain acceleration performance as much as 

possible. EPA did this by building technology packages for each vehicle type (see 

Chapter 1 of EPA’s RIA) that were designed to maintain key performance characteristics 

(e.g., effective engine displacement considering turbocharging, estimated acceleration 

performance, etc.) to the fullest extent possible. Each subsequent package generally costs 

more, provides greater fuel efficiency, and maintains performance relative to the package 

before it and, hence, the baseline or current vehicle. We have explicitly excluded 

projecting increased sales of lower powered engines as a method of reducing CO2 

emissions even in those cases where a manufacturer currently markets the same vehicle 

with two or more sized engines. To base the GHG standard on engine size or power 

would encourage manufacturers to increase engine size or power and thus, decrease fuel 

economy and CO2 emissions, while discouraging smaller engine size or power with their 

attendant benefits. Although safety concerns support the adoption of a system that 

discourages vehicle downsizing as a compliance strategy, they do not support the 

adoption of a system that discourages reductions in the size and/or power of engines in 

performance vehicles. 

Porsche, for example, states that the purpose of their small sports cars is to provide 

performance, while that of other small vehicles is to provide fuel economy (and 

commensurately, low CO2 emissions). As stated above, we have included high 

performance vehicles when developing the standard curve shapes, as well as their 

absolute levels and have maintained the performance levels of these vehicles when 

3-37 
EPA Response to Comments 

applying fuel-saving and CO2-reducing technology. However, we believe that it would 

be inappropriate to base the GHG standard using engine size or power as an explicit 

attribute. Such engines inherently operate at a low level of fuel efficiency at normal 

highway speeds. Thus, to include engine power or vehicle performance as an attribute 

upon which to set the GHG standard would be to encourage vehicles with inherently high 

CO2 emissions, which is directly counter to the expressed goals of the final rule. Also, 

since it takes more power to move a larger vehicle, the use of footprint as the attribute 

upon which to base the GHG standard indirectly includes the impact of a larger engine on 

the GHG standard. However, this is done to enable the utility of the larger vehicle with 

larger passenger and cargo capacity. 

Porsche further states that they would be required to be the most fuel efficient 

manufacturer in the U.S. due to their small average footprint. However, other 

manufacturers of small vehicles must achieve the same fuel efficiency. Porsche did not 

assert, nor establish that the proposed standards were more stringent for smaller footprint 

vehicles than for larger footprint vehicles. Thus, the fact that their overall average fuel 

efficiency would be required to be higher than other manufacturers does not mean that 

the proposed, nor final standards are more stringent for Porsche than for other 

manufacturers. (Note further that the final GHG rules contain an alternative standard for 

manufacturers with domestic sales of 2009 MY light duty vehicles of less than 50,000 

allowing such manufacturers to select any combination of 2012 through 2015 MY light 

duty vehicles to meet the Temporary Lead Time Allowance alternative standard, up to a 

cumulative total of 200,000 vehicles. An additional 50,000 2016 MY vehicles may be 

included under this alternative as well. Section 86.1818-12 (e) (3). Porsche may choose 

this alternative (assuming it meets the various eligibility criteria in the rule) to obtain 

needed leadtime to ultimately meet the main CO2 standards for its fleet.) 

BMW commented that there is evidence that the footprint-based standards are leading to 

increased sales of large trucks. We are not aware of such evidence. EPA's projection of 

future sales of large trucks and SUVs in the NPRM did show relatively large sales 

volumes. However, as discussed in the Joint TSD, this was due primarily to the mistaken 

inclusion of vehicles over 8,500 pounds GVWR which are not subject to the final 

standards. We believe that any remaining increase in future large truck sales is due 

primarily to the anticipated rebound in the economy and not to the footprint standards. 

The design of the final footprint standards is intended to avoid incentives for 

manufacturers to increase or decrease the size of their vehicles. 

Comments concerning the flattening of the standard curves at low and high footprint 

values will be addressed in section 3.2.2 below. 

3.2.2 Mathematical shape of the footprint-based standards 

Organization:General Motors 

Ford Motor Company 

Honda Motor Company 

Alliance of Automobile Manufacturers (Alliance) 

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EPA CO2 Standards 

Toyota Motor North America 

University of California, Santa Barbara, Bren Working Group on Vehicle 

Fuel Economy 

University of Pennsylvania, Environmental Law Project 

Recreational Vehicle Industry Association (RVIA) 

Comment:

General Motors 

The agencies “seek comment on the ... methodology for apportioning the fleet 

stringencies to relative car and truck standards for 2012-2016.” GM recommends: 1) 

modifying the slope of the truck curves such that large pickups have a lesser obligation, 

and 2) changing the large footprint “cut points” or “clips” from 66 ft2 to 72 ft2 to parallel 

the methodology applied to passenger cars (i.e. to affect only models with “extremely 

low sales volumes”) The statistical application of an un-weighted mean absolute 

deviation places inappropriate and additional burden on large pickups and full line 

manufacturers. Using a sales-weighed least square regression (as shown below) more 

appropriately applies the overall industry goal across the entire fleet. [OAR-2009-0472-

6953.1, p.27] 

Further, the agencies propose “to “cut off” the linear portion of the passenger car function 

at 56 square feet” primarily because of “extremely low sales volumes” for passenger cars 

are larger than this footprint. This treatment of the data is equitable and appropriate; 

however the agencies discard this equitable approach in the treatment of larger trucks. In 

fact as shown in the table below (shown for 2016 MY but likewise applicable to all 

model years of the program), the agencies’ arbitrary “cut point” for large trucks affects a 

much larger volume of the fleet. [OAR-2009-0472-6953.1, p.27] 

To propose a specific solution to the curve fitting methodology, it is helpful to re-iterate 

the parameters that EPA uses to define the curve: 

EPA mathematically defines the piecewise linear curves as follows: 

Target = a, if x ≤ l 

Target = cx + d, if l < x ≤ h 

Target = b, if x > h I 

in the constrained linear form applied by NHTSA, this equation takes the simplified 

form: 

Target = MIN [ MAX ( c * x + d , a) , b] 

Where: 

3-39 
EPA Response to Comments 

Target = the CO2 target value for a given footprint (in g/mi) 

a = the minimum target value (in g/mi CO2) 

b = the maximum target value (in g/mi CO2) 

c = the slope of the linear function (in g/mi per sq ft CO2) 

d = is the intercept or zero-offset for the line (in g/mi CO2) 

x = footprint of the vehicle model (in square feet, rounded to the nearest tenth) 

l & h are the lower and higher footprint limits or constraints or (“kinks”) or the boundary 

between the flat regions and the intermediate sloped line (in sq ft) 

Specifically, GM recommends: 1) Modifying the slope of the truck curves such that 

large pickups have a lesser obligation; specifically increase (in EPA metric of g/mi CO2) 

“c” parameter 2) Changing the large footprint “cut points” or “clips” from 66 ft2

 to 72 ft2

to parallel the methodology applied to passenger cars; specifically increase (in EPA 

metric of g/mi CO2) the “b” parameter. [OAR-2009-0472-6953.1, p.28] 

Ford Motor Company 

Fitting the Curves 

Ford recommends that the agencies use the same approach when setting the truck 

piecewise linear curve lower limit that was used for setting the car and truck upper limit 

and the car lower limit. For example, Ford agrees with the methodology used to establish 

the car upper limit that took into account the volume of vehicles (less than 10%) 

represented below a certain footprint and also the unique characteristics of those vehicles. 

The agencies state that the cars below a certain footprint have 'characteristics that could 

make it infeasible to achieve the very challenging targets that could apply in the absence 

of a constraint'. Further the agency noted the maximum value for passenger cars was 

determined based on extremely low volume sales of four luxury vehicles. 

The agency noted that there is limited public information regarding the sales volumes of 

many different configurations (cab designs and bed sizes) of pickup trucks, most of the 

largest pickups (e.g., the Ford F-150, GM Sierra/Silverado, Nissan Titan, and Toyota 

Tundra) appear to fall just above 66 square feet in footprint. NHTSA is therefore 

proposing to 'cut off' the linear portion of the light truck function at 66 square feet. Ford 

disagrees with this assessment. Ford agrees with the Alliance assessment that a large 

volume of the trucks are between 68-72 square feet. This significant volume of trucks 

above the 66 square foot limit, makes this limit function more as a 'backstop.' 

Ford strongly supports the Alliance recommendation for the agencies to move the lower 

limit for the truck piecewise linear curve to 72 square feet to recognize where the fleet is 

3-40
EPA CO2 Standards 

at today and avoid both market distortions and the GHG/CAFE backstop effect it could 

impose. Ford further recommends that the agencies use the same methodology applied to 

both the car upper and lower limit and the truck upper limit, which takes into account not 

only the volume of vehicles affected by the limit, but more importantly the unique 

characteristics (towing capacity and/or cargo hauling capability) of those vehicles that 

could make it infeasible to achieve the very challenging targets that would apply in the 

absence of the constraint adjustment. [OAR-2009-0472-7082.1, p. 4] 

Honda Motor Company 

Honda notes that the passenger car GHG and MPG attribute curve stringencies are 

capped for vehicles with footprints smaller than 41 square feet. The 41 square foot cap 

roughly aligns with the smallest 10% of the passenger car market. This cap will create the 

possibility that OEMs can offer consumers lower cost solutions to greenhouse gas 

reduction and higher fuel economy. In other words, as the stringency increases each year, 

the only solution for OEMs to meet these tougher standards is to increase the technology 

– and therefore the costs – that are applied to vehicles of the same footprint. Vehicles 

small enough to fit under the footprint cap will be able to meet the increased stringency 

simply by being small, and potentially less technology – and costs – need to be applied. 

Consumers who choose to downsize to these smaller vehicles can benefit from the lower 

greenhouse gas emissions and increased fuel economy of these vehicles while 

minimizing the cost impact. [NHTSA-2009-0059-0095.1, pp.5-6] 

Honda strongly supports the creation of a similar cap for the truck GHG and MPG 

attribute curves. Currently the 41 square foot cap is applied to both passenger cars and 

trucks, however, the 41 square foot cap for trucks does not correspond to any current 

trucks on the market, so it is effectively meaningless. A similar cap for trucks would set 

the cap approximately where the smallest 10% of the truck fleet can be found. According 

to data from the 2011 MY CAFE NPRM, the smallest 10% of the truck fleet is found at 

approximately 46 square feet (see Attachment 1). Trucks provide consumers with 

increased functionality, and as such, not all consumers can downsize from trucks to cars. 

By enabling truck customers to downsize within the truck category, customer choice will 

be protected. [NHTSA-2009-0059-0095.1, p.6] [See [NHTSA-2009-0059-0095.1, p.14 

for Attachment 1]] 

Alliance of Automobile Manufacturers (Alliance) 

Truck Clip 

With vehicle size-based standards (i.e., footprint) based on a continuous curve, all models 

have a specific target fuel economy and CO2 emissions level. Larger vehicles receive a 

standard that reflects a fundamental of physics: that a larger vehicle requires more energy 

than a smaller one (with equivalent technology levels). 74 Fed. Reg. 49470. [OAR-2009-

0472-6952.1, p. 30] 

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EPA Response to Comments 

This scientific relationship holds true for a continuous footprint function until clips are 

imposed. A “clip” is defined as a region where the footprint-fuel economy (or CO2) 

relationship is replaced with a constant (“clipped”) value for fuel economy (or CO2) 

regardless of footprint. [OAR-2009-0472-6952.1, p. 30] 

The Alliance notes the high-side clip regions could force manufacturers to limit 

production of vehicles that are above the high-side clip or cause manufacturers who 

currently produce more vehicles above the high-side clip region to drastically change 

their products whereas other manufacturers would not be required to make such changes. 

Also, this option may deny customers the full range of vehicles that meet their needs 

within the clip region – this is especially true on the truck fleet. [OAR-2009-0472-6952.1, 

pp.30-31] 

The high-side clip on the car fleet affects significantly less than 1% of the fleet but the 

high-side clip on the truck fleet is centered on the volume of the full size pickup trucks. 

[OAR-2009-0472-6952.1, p.31] 

It appears EPA and NHTSA assumed that these full size pickup trucks were at or about 

66 square feet, when in fact a large volume of them are at 68-72 square foot footprint. 74 

Fed. Reg. 49,472. This significant volume of trucks above the clip, make this clip 

function more as a “backstop.” [OAR-2009-0472-6952.1, p.31] 

NHTSA cannot subject a vehicle to both a class standard and an overall standard. This is 

contrary to the legislative scheme of placing a vehicle is placed in a single compliance 

fleet, and contrary to NHTSA’s past interpretations. During the time when NHTSA set 

2WD and 4WD/AWD CAFE standards for light trucks, the “combined standard” was an 

option (i.e. an alternative to compliance with the class standard), and NOT an additional 

requirement. Subjecting manufacturers to a CAFE backstop would perpetuate the 

anticompetitive and antisafety consequences of the fleet average system that Congress 

abandoned with the passage of the Energy Independence and Security Act of 2007, Pub. 

L. 110-140 (EISA). [OAR-2009-0472-6952.1, p.31] 

If the objective of the footprint system is to develop a regulatory framework that is 

superior to the non-attribute-based fleet average system, the high-side truck clip acts as a 

'GHG/CAFE backstop' and simply places a new layer of regulations on top of the 

footprint curve, creating more complexity for both manufacturers and the two agencies. 

[OAR-2009-0472-6952.1, p.31] 

The Alliance recommends that the agencies move the high-side clip on the truck curve to 

72 square feet to recognize where the fleet is at today and avoid both market distortions 

and the GHG/CAFE backstop effect it could impose. This would reflect a consistent 

approach with the methodology that the agencies employed in setting the passenger car 

high-slide clip. [OAR-2009-0472-6952.1, p.31] 

Toyota Motor North America 

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EPA CO2 Standards 

Shape of Target Curves 

The agencies requested comment on several aspects of the proposed target curves and the 

manner in which the curves were developed. [OAR-2009-0472-7291, p.11] 

In general, Toyota supports the overall shape of the proposed target curves. In particular, 

the proposed car target curves represent an improvement over NHTSA's 2011 model year 

final rule car curve. In that rulemaking, the car curve adopted by NHTSA was quite 

'steep' in the middle footprint ranges. The steepness of that curve had two possible 

negative effects. First, from a competitive standpoint, competing vehicles in the 

marketplace with slightly different footprints could have meaningfully different targets, 

which could provide an advantage for certain manufacturers in certain market segments. 

Second, a steep curve could provide an incentive to upsize a model in order to secure a 

relaxed target. [OAR-2009-0472-7291, pp.11-12] 

The proposed car curves are 'flatter' than the 2011 model year curve as shown in Figure 5 

below, particularly in the early model years. Note the figure shows the NHTSA car 

curves in MPG space, and compares the 2012 and 2016 model year slopes to the 2011 

model year curve. Toyota supports this trend in flattening the car target curves. [OAR2009-0472-7291, p.12] 

With respect to the truck curves, the slope of the proposed curves is very similar to the 

2011 model year truck curve adopted by NHTSA as shown in Figure 6. Again, the figure 

shows the NHTSA truck curves in MPG space, and compares the 2012 and 2016 model 

year slopes to the 2011 model year curve. Toyota supports the general continuation of 

this slope for the truck curves. [OAR-2009-0472-7291, p.12] 

Another key aspect of the proposed target curves is the 'cut-off' (or clip) at footprints 

below 41 square feet and above 56 square feet for cars and above 66 square feet for 

trucks. A comparison of the final 2011 model year car and truck curves and the proposed 

2012 and 2016MY curves is shown in Figures 7 and 8. While the constrained logistic 

function used for 2011 model year does not have a true clip from a 

mathematical viewpoint, the 2411 model year target curves for both cars and trucks 

largely flatten out to form effective clips at both ends of the curve. [OAR-2009-0472-

7291, pp.12-13] 

For smaller footprint vehicles, the current proposal extends the effective clip down to 41 

square feet, requiring additional improvements in smaller cars and trucks . At the same 

time, maintaining some level of clip also ensures that the smallest and most fuel efficient 

vehicles are not unduly penalized by setting targets so high as to price these vehicles out 

of the most price-sensitive market segment. Toyota supports the clip at the smaller 

footprint range, and would not support eliminating the clip (requiring ever increasing 

target for smaller vehicles). For larger footprint vehicles, Toyota has no comment other 

than to recognize the current proposal clips both the car and truck curves at nearly the 

same footprint as the 2011 model year car and truck curves. [OAR-2009-0472-7291, 

p.13] 

3-43 
EPA Response to Comments 

University of California, Santa Barbara, Bren Working Group on Vehicle Fuel 

Economy 

A second issue concerns the shape of the fuel economy curves. The reason for using a 

curve instead of a single fuel economy target as in the original CAFÉ standards is to 

prevent excessive downsizing as a strategy for meeting fuel economy targets. However 

some downsizing is appropriate if it is done gradually. It makes little sense to structure 

the regulation to actively discourage downsizing. We recommend that the slope of the 

curve be made shallower over time. Making the slope flatter would raise the fuel 

economy standard at the 'backstop' of 56 square feet (or 66 square feet for light trucks). 

The flattening of the slope coincides with the consideration that new innovations will be 

developed between now and when the enforcements are enacted. [OAR-2009-0472-

7188.1, p. 4] 

It should be recognized that the stated purpose of the slope of the curve is to ensure that 

there would be 'no significant effect on the relative distribution of different vehicle sizes 

in the fleet, which means that consumers will still be able to purchase the size of vehicle 

that meets their needs'. The sloping curve allows for regulators to apply targets to 

vehicles of all sizes with relatively equal stringency. It is predicted that this equal 

distribution of stringency will result in relatively similar increases in vehicle efficiency in 

vehicles of all footprints, in order to prevent the proposed regulation from influencing 

consumer choice and market-driven forces. [OAR-2009-0472-7188.1, p. 4] 

If the manufacturer succeeds in increasing a vehicle model's footprint while minimizing 

its decline in fuel economy, they may obtain emission credits that they would not have 

otherwise earned, undermining the regulation’s core purpose. Since the slope of the curve 

currently does not change as it increases annually, this incentive will be present 

throughout the 2012-2016 period. [OAR-2009-0472-7188.1, p. 5] 

Therefore, we recommend an incremental increase in stringency of the footprint curve 

which takes technology-forcing into account by gradually flattening the slope of the 

curve, possibly attaining a flat, fleet wide fuel economy target in the future. The 

flattening of the curve will pose a greater obstacle for larger, less fuel efficient cars to 

meet the proposed standards, and at the same time assure the anticipated market shift 

toward vehicles with smaller footprints, resulting in higher fuel economy. In addition to 

efficiency innovations, this shift toward smaller, more fuel-efficient cars is a critical 

factor in making significant, tangible nation-wide reductions in vehicle greenhouse gas 

emissions. By meeting and exceeding more stringent curves, American manufacturers 

will place themselves at the forefront of the global technology frontier, thus helping to 

regain our role as an economic leader. [OAR-2009-0472-7188.1, p. 5] 

Moreover, we recommend that the method with which the curves were drawn be made 

transparent in the support documentation. Any equations and formulae utilized to derive 

the curve should be made publicly available. We attempted to use the VOLPE model 

output data from NHTSA's website to reproduce the footprint curve, in order to assess the 

method with which the curve was drawn. According to the technical support document, 

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EPA CO2 Standards 

the mean absolute deviation (MAD) regression was used to draw the slope between the 

maximum and the minimum footprints (41sq ft to 56 sq ft for passenger vehicles). 

However, we were unable to reproduce the maximum technology curve and, therefore, 

could not compare the MAD methodology to alternative regressions. [OAR-2009-0472-

7188.1, p. 5] 

Despite direct communication with NHTSA, we were unable to clarify these questions 

and replicate the exact slope and intercept given in the VOLPE model output. According 

to testimony at the Los Angeles hearings, the Environmental Defense Fund similarly had 

difficulty replicating the NHTSA analysis. This is a crucial piece of information, as the 

curve is the central tool with which the fuel economy targets are assigned. If the method 

is made transparent, then commentators could also make better informed 

recommendations to the proposal. [OAR-2009-0472-7188.1, p. 5] 

University of Pennsylvania, Environmental Law Project 

While it is important that the regulation avoid providing perverse incentives to vehicle 

manufacturers, predictability and gradualness are also important features of the 

regulation. These features ensure that the cost of compliance will be relatively low, as 

auto manufacturers are given time to incorporate improvements into the standard design 

timeline. Thus, we recommend that the regulation gradually reduce the disparity between 

the efficiency requirements for larger and smaller vehicles such that it is 

significantly reduced between model years 2012 and 2016. This reduction would take the 

form of a decreasing slope in the standard curves between 2012 and 2016, as well as a 

decrease in the difference between the height of the car and truck curves. [OAR-2009-

0472-7286.1, pp. 17-18] 

 Recreational Vehicle Industry Association (RVIA) 

The NPRM proposes fuel economy/CO2 target curves for light trucks which flatten out at 

the 66 square feet footprint value. It is our understanding, however, that there are lightduty vehicle tow vehicles currently in the marketplace which have a volume [sic: 

footprint] in the range of 68 to 72 square feet. In flattening out the curve at 66 square feet, 

vehicles up to 72 square feet footprint range will be expected to achieve the same fuel 

efficiency as vehicles having a footprint of 66 square feet. We urge EPA and NHTSA to 

correct this oversight and adjust the target curves so that these larger vehicles, especially 

since they are used for towing, are not penalized by the standards. Failing to do so risks 

manufacturers downsizing these tow vehicles or eliminating them altogether from the 

product mix. Either of these actions will be detrimental to highway safety and to the RV 

industry and individual who tow RVs. [NHTSA-2009-0059-0107, p.5] 

EPA Response:

There are several key aspects to the mathematical form of the footprint-based standards 

which were commented upon. These were: 1) the statistical methods used to develop the 

slope of the car and truck curves, including the resultant slopes of these curves, and 2) the 

3-45 
EPA Response to Comments 

lower and upper footprint values where the curves flatten out. We address each of these 

aspects below. 

The slopes of the footprint-based standard curves in the NPRM were based on a 

minimization of the sum of the absolute differences between the individual vehicle data 

points and the curve, often referred to as minimum mean absolute deviation or MMAD. 

Each vehicle's data point was assigned the same "weight" in this summation. The 

primary alternatives to this technique would be to 1) use least-square regression and 2) 

sales-weight each vehicle's data point. GM, for example, recommended that both 

alternatives be used in lieu of the non-sales weighted MMAD regression. 

The MMAD regression technique differs from least square regression primarily in that it 

reduces the influence of data points which deviate the most from the curve. Least square 

regression by definition squares this deviation before summing, while MMAD simply 

adds the deviation to the sum of differences. Examination of the vehicle data used to 

develop the curves indicates that the fuel consumption and CO2 emission levels of 

individual vehicles having similar footprints vary widely, often by as much as 50%. This 

extreme variation can indicate the absence of a normally distributed dataset, often 

indicating the need to use a statistical technique that reduces the influence of outlying 

data points.1 

With respect to recommendations that NHTSA and EPA use weighted least-squares 

analysis, the agencies find that the market forecast used for analysis supporting both the 

NPRM and the final rule exhibits the two key characteristics that previously led NHTSA 

to use minimization of the unweighted rather than sales-weighted analysis. The agencies’ 

intention is to fit a curve that describes a technical relationship between fuel economy 

and footprint, given comparable levels of technology, and this supports weighting 

discrete vehicle models equally. However, there are some aspects of vehicle design which 

are known to influence fuel consumption and CO2 emissions, such as acceleration 

performance and amenities which can increase vehicle weight. To the extent that the 

distribution of these preferences is not equally distributed across the range of footprint 

values, vehicles with relatively extreme attributes and low sales levels could affect the 

slope of the curves. 

 

1

 In the case of a dataset not drawn from a sample with a Gaussian, or normal, distribution, there is often a 

need to employ robust estimation methods rather than rely on least-squares approach to curve fitting. The 

least-squares approach has as an underlying assumption that the data are drawn from a normal distribution, 

and hence fits a curve using a sum-of-squares method to minimize errors. This approach will, in a sample 

drawn from a non-normal distribution, give excessive weight to outliers by making their presence felt in 

proportion to the square of their distance from the fitted curve, and, hence, distort the resulting fit. With 

outliers in the sample, the typical solution is to use a robust method such as a minimum absolute deviation, 

rather than a squared term, to estimate the fit (see, e.g., ‘‘AI Access: Your Access to Data Modeling,’’ at 

http://www.aiaccess.net/English/Glossaries/GlosMod/e_gm_O_Pa.htm#Outlier). The effect on the 

estimation is to let the presence of each observation be felt more uniformly, resulting in a 

curve more representative of the data (see, e.g., Peter Kennedy, A Guide to Econometrics, 3rd edition, 1992, 

MIT Press, Cambridge, MA). 

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EPA CO2 Standards 

In conducting analysis to support its rulemaking for MY2011 CAFE standards, NHTSA 

evaluated several combinations of these two aspects of the curve setting techniques. 

Most combinations yielded slopes for the car curve that were believed to give 

manufacturers too great an incentive to upsize their vehicles. In other words, the change 

in allowed fuel consumption or CO2 emissions with an increase in size was deemed to be 

greater than that which would inherently result from a larger vehicle platform, as 

supported by Toyota. This belief was despite the fact that the slopes of these curves 

reflected the change in fuel consumption or CO2 emissions with a change in vehicle 

footprint. Considering this, and considering the technical issues discussed above, 

NHTSA selected techniques that yielded a car curve with what it believed to be an 

acceptable slope. NHTSA and EPA have continued to apply those techniques in 

connection with the final rule, though with a constrained linear curve as opposed to a 

constrained logistic curve, which in part resulted in a car curve slope lower than that in 

the middle of the 2011 MY constrained logistic curve. 

This choice of statistical techniques also yielded a slightly lower slope for the truck curve 

than several other combinations of the available statistical techniques. A lower truck 

slope increases the stringency of the standard for larger trucks relative to smaller trucks. 

This appears to be GM's concern, as GM's truck sales are oriented towards the larger 

truck segment of the market. GM's suggestion to use sales weighted least square 

regression is not supported by any additional information beyond that provided by the 

two agencies in the proposed rule. GM and Ford did challenge the two agencies' 

projections that their larger trucks could meet the proposed standards. These comments 

are addressed in section 3.3 of this RTC document. GM did not address the issue of the 

increased slope for cars, which would accompany their recommended 

statistical technique. Overall, the two agencies continue to believe that the use of 

unweighted MMAD regression produces the best results for this dataset and that no 

arguments exist which clearly indicate that this approach should be rejected. Thus, the 

two agencies fitted the car and truck curves using the same statistical techniques as those 

used in the NPRM. It is possible that EPA and NHTSA would reconsider the statistical 

techniques used to develop the standard curves in future rulemaking. 

Regarding the lower and upper footprint values where the standard curves flatten out, 

GM recommends that the upper footprint value for trucks be increased to 72 square feet 

from 66 square feet. Their argument is based on the fact that the upper footprint value for 

cars of 56 square feet affects very few sales. Thus, the upper footprint value for trucks 

should do the same. 

This argument does not address the interaction between the car and truck curves and how 

they together regulate the light vehicle fleet. For example, the lower limit of the car 

curve was set at 41 square feet. Roughly 10% of car sales fall below this level. Were the 

lower limit of the truck curve to be set at footprint value where 10% of truck sales fell 

below its value, the lower limit of the truck curve would have been well above 41 square 

feet. The truck curve is already well above the car curve in terms of fuel consumption or 

CO2 emissions at lower footprint values. If the truck curve were to flatten out at a 

footprint value of, for example, 46 square feet as suggested by Honda, the difference 

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EPA Response to Comments 

between the two curves would become even greater for vehicles below 46 square feet. 

The incentive to convert cars with footprints below 46 square feet to trucks would have 

been extremely large. Thus, even though few current trucks are sold with footprints 

below 41 square feet, protecting the overall goal of the two programs makes it clear that 

the lower footprint limit of the truck curve should be the same as or very similar to that 

for the car curve. Thus, Honda's comment that the 41 square foot cutpoint for the truck 

curve is meaningless is not correct. 

Since trucks tend to have larger footprints than cars, it makes similar sense to set the 

upper limit of the truck curve in the same way as the lower limit of the car curve (i.e., at 

the point where roughly 10% of sales exceed the limit). This is roughly 66 square feet. 

Analogous to the setting of the lower limit of the truck curve at the same level as the 

lower limit of the car curve, we could have set the upper limit of the car curve at 66 

square feet. However, there are very few car sales above 56 square feet, so the point is 

essentially moot as to setting the upper limit of the car curve at 56 or 66 square 

feet. GM's arguments starts by setting of the upper limit of the car curve and then setting 

that of truck curve to the same level. This is incorrect from a policy perspective. The 

lower limit of the two curves is set based on that vehicle class with the smaller vehicles 

(i.e., cars) and the upper limit of the curves is set based on that vehicle class with the 

larger vehicles (i.e., trucks). 

While GM, Ford and AAM assert that a large volume of truck sales exist with footprints 

between 68 and 72 square feet, detailed data supporting this claim, which could have 

been incorporated into the two agencies' analyses, were not provided. As discussed in 

section 3.4 of this RTC document, there is value from a policy perspective for a backstop 

which increases the likelihood that the projected benefits of these rules actually occurs. 

Thus, the fact that the upper limit on the truck curve serves to a small degree as an 

indirect backstop on fuel consumption and CO2 emissions is not in itself a problem. We 

also note that most vehicles which are marketed as "low-priced" or "economical" are very 

small in size. This implies that sales of these vehicles would be the most sensitive to 

increases in cost due to the addition of fuel saving technology. Trucks above 66 square 

feet in footprint do not fall into this category. In contrast, these vehicles are typically on 

the high end of the market in many respects and should be in a good position to absorb 

the cost of the technologies which the agencies project will enable their compliance. 

Toyota suggests reducing the slopes of the car and truck curves over time to encourage a 

gradual downsizing of both the car and truck fleets. The two agencies did not decide to 

do this at the present time, primarily because the agencies are attempting use attributebased standards to discourage downsizing that might compromise highway safety and to 

more equitably distribute compliance burdens, not to encourage vehicle downsizing 

beyond levels consistent with normal market demands. Of course, the agencies will 

reconsider appropriate ways to fit the car and truck curves for purposes of subsequent 

rulemakings. 

Since the fitted slopes of the two curves were based on vehicle data which reflected the 

use of all available technologies other than diesel and strong hybridization, we do not 

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EPA CO2 Standards 

believe that there is an inappropriate incentive for manufacturers to upsize their vehicles 

in order to reduce the need to add fuel saving and CO2 reducing technology. 

As described in section II.C of the preamble to the final rule, NHTSA did correct several 

errors in its analysis used to fit the slopes of the curves, allowing the commenters to 

reproduce the results. The refitted passenger car curve is similar to that presented in the 

NPRM, and the refitted light truck curve is nearly identical to the corresponding curve in 

the NPRM. However, the slope of the refitted passenger car curve is about 27 percent 

steeper (on a gram per mile per square foot basis) than the curve presented in the NPRM, 

and would increase stringency for the smallest cars, decrease stringency for the largest 

cars, and provide a greater incentive to increase vehicle size throughout the range of 

footprints within which NHTSA and EPA project most passenger car models will be sold 

through MY 2016. The agencies are concerned that these changes would make it unduly 

difficult for manufacturers to introduce new small passenger cars in the United States, 

and unduly risk losses in feasible and cost-effective energy and environmental benefits by 

increasing incentives for the passenger car market to shift toward larger vehicles. 

Considering NHTSA’s and EPA’s concerns regarding the change in incentives that 

would result from a refitted curve for passenger cars, the agencies are finalizing CAFE 

and GHG standards based on the curves presented in the NPRM. 

3.2.3 Relative stringency of the car and truck standards 

Organization: General Motors 

Northeast States for Coordinated Air Use Management 

International Council on Clean Transportation 

University of California, Santa Barbara, Bren Working Group on Vehicle 

Fuel Economy 

University of Pennsylvania, Environmental Law Project 

South Coast Air Quality Management District 

Comment:

General Motors 

The overall industry goal of 250 CO2 g/mile (35.5 mpg equivalent) by 2016 model year is 

tough, but reasonable. This target can, however, be distributed between the separate car 

and truck fleets in an infinite number of combinations. In our comments, we provide an 

analysis for adjusting the proposed distribution to achieve a more equitable burden on the 

truck fleet. Our analysis shows that today’s most efficient, segment leading cars and 

small trucks already meet the 2016 model year targets, but the segment leading and most 

efficient large pickups are required to improve by 20% to meet their 2016 MY 

requirements. Our analysis shows that over estimated benefits of added fuel economy 

technology and future pickup truck volumes result in a disproportionate burden being 

placed upon large pickups. GM recommends that in each year of the rule, the agencies 

better balance the respective obligations of passenger cars and trucks – while still 

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EPA Response to Comments 

reaching the same end point for the car and truck fleets combined in 2016. [OAR-2009-

0472-6953.1, p.2] 

GM recommends that in each year of the rule, the agencies better balance the obligation 

for large pickups as compared to passenger vehicles. Today’s most efficient, segment 

leading cars and small trucks already meet the 2016 model year targets but the segment 

leading, most efficient large pickups are required to improve by 20% to meet their 2016 

MY requirements. [OAR-2009-0472-6953.1, p.4] [[See pp.4-8 of OAR-2009-0472-

6953.1 for a discussion on GM's analysis of the truck efficiencies]] 

Northeast States for Coordinated Air Use Management 

Separate footprint curves for cars and light trucks: NESCAUM encourages EPA and 

DOT to maintain a single footprint curve for cars and light trucks in the final regulation. 

By establishing two curves as EPA and DOT have proposed, there is a significant risk 

that automobile manufacturers will “game” the standard. This can be done, for example, 

by making four wheel drive small SUVs rather than two wheel drive small SUVs so that 

cars become classified as trucks. If manufacturers reclassify cars as light trucks as has 

happened before, GHG emissions and fuel consumption could increase 

significantly. [OAR-2009-0472-7235.1, p.4] 

[Northeast States for Coordinated Air Use Management also submitted these comments 

as testimony at the New York public hearing, See docket number OAR-2009-0472-4621, 

p. 43.] 

International Council on Clean Transportation 

[[These comments were submitted as testimony at the Detroit public hearing. See docket 

number EPA-HQ-OAR-2009-0472-6185, p. 59.]] 

We also support the proposed change to the shape of the footprint adjustments. Target 

standards versus the vehicle footprint provide consistent signals to improve efficiency for 

most vehicles while preserving incentives to make the largest vehicles smaller. 

[[These comments were submitted as testimony at the Detroit public hearing. See docket 

number EPA-HQ-OAR-2009-0472-6185, pp. 61-62.]] 

First, the proposed rule maintains separate footprint curves for cars and light trucks. This 

subjects light trucks with the same footprint to much less stringent standards and gives 

manufacturers a tremendous incentive to reclassify cars as light trucks. In the past this 

has brought us such notable trucks as the Subaru Outback, Chrysler P.T. Cruiser, Dodge 

Magnum, Mazda 5, Porsche and BMW X6, BMW describes as a sports activity coupe. 

In the future it is likely to cause manufacturers to drop many 2-wheel drive versions of 

their small sport utilities and make less efficient 4-wheel drive versions standard so that 

they can be classified as light trucks instead of cars. Each car to light truck sales shift 

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EPA CO2 Standards 

results in easier compliance for manufacturers but higher in use fuel consumption and 

greenhouse gas emissions in use. 

EPA recognized the importance of this issue when it established a single tier 2 emissions 

standard that applied to all cars and light trucks. It is time to do the same for fuel 

efficiency and greenhouse gas emissions and end this artificial distinction. A single 

footprint function will still give larger trucks a less stringent target while avoiding vehicle 

classification games. 

University of California, Santa Barbara, Bren Working Group on Vehicle Fuel Economy 

While the proposed rule itself will not alter fleet composition, the EPA and NHTSA have 

projected a market-driven shift from the current mix of vehicles (51% passenger cars, 

49% light trucks) towards a vehicle mix of 67% passenger cars and 33% light trucks by 

2016. However, the market simply may not respond in the manner projected in the 

proposal, or the shift may not occur with market power alone. The Union of Concerned 

Scientists contend that vehicles slated to be reclassified as passenger vehicles (e.g. 2-

wheel drive SUVs) could be equipped with other light truck attributes to qualify for light 

truck classification. As long as there is a separate, less stringent footprint-curve for light 

trucks, there will be a strong incentive on the part of auto-makers to classify their 

vehicles as light trucks. While the curve evenly distributes the penalties, it also rewards 

vehicles with larger footprints, which inherently tend to have a lower fuel economy. Not 

only does the footprint-based curve discourage downsizing of vehicles, it introduces 

incentives for manufacturers to maximize the footprint for a given model, so that a model 

will have a less stringent target fuel economy. This may include shifting the wheelbase to 

a wider, boxy shape, or elongating the vehicle. [OAR-2009-0472-7188.1, p. 4] 

University of Pennsylvania, Environmental Law Project 

While it is important that the regulation avoid providing perverse incentives to vehicle 

manufacturers, predictability and gradualness are also important features of the 

regulation. These features ensure that the cost of compliance will be relatively low, as 

auto manufacturers are given time to incorporate improvements into the standard design 

timeline. Thus, we recommend that the regulation gradually reduce the disparity between 

the efficiency requirements for larger and smaller vehicles such that it is 

significantly reduced between model years 2012 and 2016. This reduction would take the 

form of a decreasing slope in the standard curves between 2012 and 2016, as well as a 

decrease in the difference between the height of the car and truck curves. [OAR-2009-

0472-7286.1, pp. 17-18] 

South Coast Air Quality Management District 

Third, the South Coast AQMD staff shares the concern that the attribute basis of the EPA 

 program may provide certain incentives to up-weight vehicles. 

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EPA Response to Comments 

For example, the EPA's program may result in auto manufacturer compliance strategies 

which involve up-weighting of vehicles from two-wheel drive to four-wheel drive SUV 

configurations. For this reason, the South Coast AQMD staff recommend that EPA 

consider establishing some form of backstop mechanism to ensure that the vehicle fleet 

is not dramatically distorted by perverse incentives occurring by selecting different 

vehicle weight categories. 

In conclusion, the AQMD staff certainly appreciate this opportunity to provide comment. 

We compliment the EPA and NHTSA and DOT staffs for their diligent analysis. The 

standards proposed by both of your organizations will significantly reduce greenhouse 

gas emissions as well as criteria pollutants. We are very pleased to stand here and 

strongly endorse the standards as they will provide meaningful national benefits for 

decades to come. 

[Comments are from LA Testimony, OAR-2009-0472-7283, pp.59-67] 

EPA Response:

GM's basic comment that the burden of the standards can be more equitably distributed 

between cars and trucks is a function of three aspects of the car and truck standard 

curves: 1) their relative slopes, 2) their relative intercepts at zero footprint (ignoring their 

flattening at a footprint value of 41 square feet), and 3) the lower and upper footprint 

values where the curves flatten out (and for GM, their primary focus is the 66 square foot 

cutpoint for the truck curve). The issues of the relative slopes of the car and truck curves 

and the lower and upper footprint cutpoints were addressed is section 3.2.2 above. The 

remaining issue to be addressed here is how the two agencies set the intercepts of the two 

curves, or in other words, the degree to which the truck curve was above the car curve in 

terms of fuel consumption and CO2 emissions. 

This distance between the car and truck curves was based on setting each curve at the 

level where estimated net societal benefits were maximized (as described in section II of 

the preamble). These two curves were then adjusted upwards (in terms of fuel 

consumption or CO2 emissions) to the point where the desired fleet-average fuel 

consumption or CO2 targets were achieved. Thus, this analysis reflects the cost of 

adding technology to both cars and trucks, smaller and larger vehicles, as well as the 

benefits accruing from this technology. GM has not shown why this approach produces a 

greater burden on large trucks versus smaller cars. Simply comparing current vehicles, 

even "market leading" vehicles, to the proposed standards does not establish the 

capability of adding additional, cost beneficial technology. Current market forces, 

including forces in overseas markets for some manufacturers, can lead to the uneven 

addition of technology to current vehicles. Without assessing the degree to which 

available technology has already been added to current vehicles, any such comparison 

can be misleading. We believe that the approach of adding all cost beneficial technology 

to all vehicles provides a reasonable balance of regulatory burden across the wide variety 

of vehicles currently being sold in the U.S. market. 

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EPA CO2 Standards 

Regarding NESCAUM's suggestion for a single curve for both cars and light trucks and 

other comments indicating a risk that manufacturers will shift car sales to trucks, we 

believe that there are several reasons to reject this approach for the present rule. As 

discussed above in section 3.0, EPCA requires NHTSA to set separate standards for 

passenger cars and light trucks. Also, some trucks, at least, provide utility not available 

from cars. These include cargo and towing capacity. The vehicle features required to 

provide this utility inherently increase fuel consumption and CO2 emissions relative to 

vehicles without such utility. Therefore, some distinction between car and truck 

standards appears justifiable. As also discussed in section 3.0 above, we acknowledge 

that there is some risk that manufacturers will increase the sale of AWD and 4WD 

versions of their smaller SUVs relative to 2WD versions of these vehicles, thereby 

leading to increased levels of fleetwide fuel consumption and CO2 emissions. As 

indicated above, we will monitor this situation and take necessary action as we develop 

standards for 2017 and beyond. At the present time, a shift from the historical approach 

of setting separate standards for cars and trucks to one that would tgreat them the same or 

much more similarly would lead to a large differential regulatory impact on several 

manufacturers. The current state of the auto industry and the fact that the time frame of 

these rules only extends 6 years from today argue against such a dramatic change at this 

time. 

3.3 Stringency of the standards 

Organization: General Motors 

Northeast States for Coordinated Air Use Management 

Public Citizen and Safe Climate Campaign 

American Council for an Energy Efficient Economy 

Sierra Club 

California Air Resources Board 

International Council on Clean Transportation 

US Steel Corporation 

University of Pennsylvania, Environmental Law Project 

Eadie, R. Frank 

Sack, Emily 

Comment:

General Motors 

The overall industry goal of 250 CO2 g/mile (35.5 mpg equivalent) by 2016 model year is tough, 

but reasonable. [OAR-2009-0472-6953, p.2] 

The proposed standards are not easy, nor will they be inexpensive, but we are up to the 

challenge. The success of our current offerings in the marketplace like the Chevy Malibu 

and the Equinox and the enthusiasm over soon-to-be released products like the Chevy 

Cruze convince us that we will be able to do our part, and even before this rule becomes 

effective, we will have introduced the Chevy Volt, which is scheduled to start production 

3-53 
EPA Response to Comments 

in late 2010 as a 2011 model year vehicle, and it will be GM's first extended range 

electric vehicle. [OAR-2009-0472-6185, p.11] 

Public Citizens and Safe Climate Campaign 

The agencies have not outlined an approach to setting standards that sets a precedent for 

how the agencies would approach this task the next time around. The agencies 

have engaged in economic hand waving, estimating that more stringent standards would 

be cost-effective, but then appealing to the financial state of the auto industry in choosing 

the level of standards. For example, EPA discusses other rates at which to ramp down the 

CO2 standards, looking at two options: lowering allowable CO2 emissions by four 

percent per year and six percent per year. These options are not indicated by any 

technological or economic criteria, but merely establish a range within which the 

agency’s proposal fails. EPA proposes that CO2 emissions decline at approximately 4.2 

percent per year for passenger cars and 4.5 percent per year for light trucks. [OAR-2009-

0472-7050.1, p.9] 

EPA then discusses the relative cost of compliance with standards in each scenario, and 

explains that the cost savings for setting standards at four percent instead of the proposed 

level would be $73 per vehicle, whereas the six percent alternative would incur additional 

costs of $493 per vehicle on average. EPA appeals to the financial state of the industry in 

influencing its decision: “EPA is not concluding that the 6% per year alternative 

standards are technologically infeasible, but EPA believes such standards for this time 

frame would be overly stringent given the significant strain it would place on the 

resources of the industry under current conditions. EPA believes this degree of stringency 

is not warranted at this time. Therefore EPA does not believe the 6% per year alternative 

would be an appropriate balance of various relevant factors for model years 2012–2016.” 

EPA does not substantiate this claim with an analysis that evaluates the tradeoff in terms 

of public health and welfare. [OAR-2009-0472-7050.1, p.9] 

Science dictates that to avoid the worst consequences of global warming that we must 

reduce emissions of greenhouse gases to 83 percent below 1990 levels by 2050. In order 

for the U.S. light duty transportation sector to get there, EPA must set standards that cross 

multiple product cycles and allow for much more significant transformative changes in 

the light duty vehicle fleet. The CAA requires EPA to issue standards that protect public 

health and welfare. The Supreme Court in Massachusetts v. EPA affirmed CAA authority 

to regulate greenhouse gases, and EPA has asserted that greenhouse gases pose a threat to 

public health and welfare through its proposed endangerment finding. The agency’s 

approach to setting standards must reflect its responsibility to set protective standards 

consistent with its statutory mandate. [OAR-2009-0472-7050.1, p.9] 

EPA’s consideration of health and the environment are paramount to economic 

considerations in setting standards under CAA. NHTSA has significant discretion to 

balance the four factors under EPCA for setting standards, and could choose 

technological feasibility and the need of the nation to conserve energy as the paramount 

factors in standard setting. The agency’s assessment of the industry’s capacity and 

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EPA CO2 Standards 

willingness to raise fuel economy and cut greenhouse gas emissions does not reflect 

current trends. Consumer demand for fuel efficient cars has increased significantly in 

light of gas price spikes in 2005 and 2008, and increased public awareness of global 

warming. Major automakers have been making announcements for over a year about 

ambitious plans to raise vehicle fuel economy, roll out new efficiency technology, and 

move more rapidly than expected into hybrid, plug-in hybrid, and fully electric vehicles. 

Both agencies’ assumptions about technology adoption and willingness to increase fleet 

fuel economy seem unjustifiably constrained by outdated assumptions. [OAR-2009-

0472-7050.1, p.10] 

In establishing this new program, the agencies should develop a standard-setting 

methodology that satisfies each agency’s statutory requirements, as well as the intent of 

both laws. EPCA aims to stabilize energy prices through conservation efforts. It was 

passed to establish a national energy policy that protects consumers against future price 

shocks and puts the nation in a more competitive position globally by making the nation 

less sensitive to price volatility. This vision was undermined by inconsistency in standard 

setting, and when oil prices rose sharply in 2005 and 2008, consumers were subject to 

prices shocks similar to those experienced in the 1970s. EPA has a responsibility to 

protect public health and welfare by setting standards under the CAA. The threat of 

global warming is clearer today than previously, and the agency’s authority to regulate 

greenhouse gas emissions to fulfill its mission of protecting public health and welfare has 

been affirmed. [OAR-2009-0472-7050.1, p.10] 

Both agencies should start the standard setting process by establishing oil savings and 

greenhouse gas reduction goals based on assessments of national needs. From these 

estimates, the agencies must then apply considerations appropriate to their respective 

statutes, including technological feasibility, economic considerations, and the needs of 

the nation to conserve oil and reduce greenhouse gas emissions. This would result in 

setting levels of stringency consistent with the needs of the nation that are the 

maximum feasible, as required by EPCA, and that are as technology-forcing as 

practicable, consistent with EPA’s charge to place public health and welfare above 

economic concerns. [OAR-2009-0472-7050.1, p.11] 

American Council for an Energy Efficient Economy 

Recommendations: 

Establish in the final rule that light-duty vehicle standards in subsequent rules shall be set 

to achieve medium- and long-term emissions goals for the transportation sector 

commensurate with the need for emissions reductions overall. 

Ensure that required emissions levels are sufficiently stringent to ensure that, at a 

minimum, any incremental reductions with positive net benefits are implemented. 

The stringency of the proposed rule is well below the maximum cost-effective level, as 

the agencies clearly demonstrate. Table IV.F.2 (p.49700) shows that the proposed 

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EPA Response to Comments 

standards would save 62 billion gallons per year, while a more stringent standard that 

maximizes net benefit would save 90 billion gallons, or almost 50 percent more fuel (and 

CO2 emissions). Choosing one level of standards over another that is superior on both 

environmental and economic grounds is a decision that calls for a clear explanation. The 

agencies’ rationale for doing so is not compelling, however. 

In Section III.D., EPA compares the manufacturers’ likely response to the proposed 

standards to what would be required to achieve a 4 percent per year reduction in CO2 

(slightly less stringent than the standards) and to achieve a 6 percent per year reduction 

(substantially more than the standards). EPA notes that, according to its model, the 

requisite application of advanced technologies to achieve 6 percent reductions would 

increase fleetwide, necessitating for example an 8 percent increase in the application of 

start-stop technology. Furthermore, for BMW and Daimler, for example, increases of up 

to 42 percent in hybrid production could be necessary to meet the standard. (p.49557) 

These observations do not support the view that a 6 percent per year rate is too ambitious. 

Moreover, the concern over BMW and Daimler is reminiscent of NHTSA earlier, illadvised “least-capable manufacturer” approach (to nonattribute- based standards), except 

that EPA has cited manufacturers less likely to elicit sympathy than those to which 

NHTSA applied its approach. 

EPA goes on to state that as the annual percent reduction increases from 4 to 6 percent, 

“[c]ompliance costs are entering the region of non-linearity. The $73 cost savings of the 4 

percent per year standards relative to the proposal represents $18 per g/mi CO2 increase. 

The $493 cost increase of the 6 percent per year standards relative to the proposal 

represents $25 per g/mi CO2 increase.” (p.49557) It is not clear why EPA regards this 

increase in cost-per-ton as dramatic and excessive. EPA also fails to discuss whether a 

CO2 reduction rate of 5 percent per year, for example, would be feasible. EPA proposes 

no objective measure of what is sufficiently stringent. Indeed, NHTSA’s subsequent 

discussion of the various rates of improvement the agencies considered indicates that 

even a 6 percent rate of improvement is well below the optimal rate, even from a purely 

economic perspective, without prioritization of environmental goals. 

NHTSA presents stringency options in the form of annual percent increases in fuel 

economy, with the proposed standards corresponding to a 4.3 percent per year increase. 

In IV.F., NHTSA argues that 5 percent would be too aggressive, because it would 

increases the per vehicle incremental cost by 30 percent while reducing fuel consumption 

by only 3 percent (p. 49704). This comparison in fact provides no basis for comparison 

between the proposed standard and a 5 percent annual reduction, and certainly does not 

demonstrate that the higher rate of reduction is excessively costly. If several very lowcost technologies exist to reduce fuel consumption, the next technologies on the cost 

curve might cost many times more per gallon saved while still being highly costeffective. 

The ad hoc and narrow arguments advanced by the agencies to show that standards more 

stringent than those proposed would not be reasonable are for the most part 

unconvincing, especially given that the proposed standards are far below the level that 

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EPA CO2 Standards 

maximizes net benefits. The perilous condition of the domestic auto industry may in fact 

imply that the proposed standards are the best choice for the current rulemaking. 

However, the reasons for this must be clearly articulated and formulated in a way that 

makes clear how “maximum feasible” levels are to be determined in the future. The 

inadequate explanation for the stringency of the proposed rule could have negative 

implications for subsequent rulemakings. 

The governing statutes grant the agencies substantial discretion in setting stringency, and 

ACEEE does not support the application of a rigid economic test to determine the 

appropriate levels of the standards. However, recommending a standards even below the 

maximum net benefit in economic terms calls for a special explanation. A standard that 

falls below the point on the technology cost curve where marginal costs equal marginal 

benefits would be widely acknowledged to fall short of the “maximum feasible” and 

“economically practicable” standard required under the CAFE statute. Under the Clean 

Air Act, for which economic considerations are secondary to environmental protection 

needs, the appropriate standard can only be more stringent. Maximum net benefits should 

therefore be considered a lower bound for stringency of the standards. 

The final rule should set out the principles by which stringencies will be determined in 

future rulemakings in order to ensure that standards will continue to support expeditious 

reduction of fuel use and greenhouse emissions. The ability of the standards to promote 

the development and deployment of new efficiency technologies is central to their role in 

national climate and energy security policy, so EPA and NHTSA should make clear how 

this aspect of the program will be preserved and strengthened over time. 

Given that the purpose of the EPA rule is to help achieve the reductions in GHG 

emissions necessary to reach sustainable atmospheric concentrations of carbon, those 

emissions reduction goals should inform the setting of standards in a quantitative way. 

This general approach was introduced in EPA’s GHG NPRM in 2008 and begins with 

certain assumptions about the percent reduction in GHG emissions, relative to 2005 

levels, required in milestone years out to 2050. A default assumption that sectors and 

subsectors must reduce emissions in proportion to their contribution to total emissions is 

appropriate, at least until the potential for some sectors to do more is verified. 

In such an approach, aggressive measures will be needed for the transportation sector, 

going well beyond the standards proposed in the rule, to achieve the sector’s share of the 

necessary reductions. Therefore, ACEEE believes that GHG reduction targets should be 

the principal determinant of the stringency of vehicle emissions rules in the future. 

[ACEEE also submitted these comments as testimony at the New York public hearing, 

See docket number EPA-HQ-OAR-2009-0472-4621, pp. 139, 144-146.] 

Sierra Club 

The proposed National Program combines the first national greenhouse gas standards for 

vehicles under the Clean Air Act with energy saving Corporate Average Fuel Economy 

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EPA Response to Comments 

(CAFE) standards, all while ensuring the nation benefits from the precedent set by 

California’s Pavley standards. The proposed National Program is expected reduce 

greenhouse gas emissions by 950 million metric tons, equivalent of 205 coal plants 

shutting for one year, and reduce oil consumption by 1.8 billion barrels, resulting in 

consumer savings at the pump of $193 billion. These standards must ensure the nation 

benefits from the precedent set by California’s Pavley standards to achieve a 30% 

reduction in greenhouse gas pollution from new vehicles in 2016. A strong final rule is 

needed to deliver on President Obama’s promise and to pull vehicle standards out of the 

1970s and into the 21st century. [OAR-2009-0472-7278.1, p.2] 

This NPRM includes many elements that are identified as transitional – as both agencies 

work to create a new National Program for greenhouse gas and fuel economy standards. 

While the 250 g/mi CO2e standard in the NPRM is significant, we urge that both 

agencies definitively end “transitional” elements in 2016 and indicate an intent to launch 

a standard setting process for 2017 and beyond that will meet the urgent need of the 

United States to dramatically reduce greenhouse gas pollution and conserve oil and 

[OAR-2009-0472-7278.1, p.2] meet the growing demand of American consumers for 

vehicles that go farther on a gallon of gas. [OAR-2009-0472-7278.1, p.3] 

[[These comments were submitted as testimony at the Detroit public hearing. See docket 

number OAR-2009-0472-6185, pp. 30-31.]] 

EPA and NHTSA should clarify the approach to setting standards. As we know, the 

proposed standards of 250 g/mi and 34.1 mpg are the result of an agreement; however, 

future rounds of standards will likely not be bound by a similar agreement and, in fact, 

both agencies should ensure that future standards maximize the application of costeffective technologies to vehicles and consumer savings at the pump. The Clean Air Act 

is a technology forcing statute, and we urge EPA to clearly note the transitional aspect of 

these standards in the final rule. 

These standards will move us from one standard aimed at reducing oil consumption, to a 

broader National Program that also guarantees greenhouse gas emissions reductions. The 

proposed National Program sets the table for future standards that can finally break our 

dependence on oil and create substantially cleaner vehicles. 

California Air Resources Board 

First, the Final Rule needs to maintain the proposed standards’ stringency in each model 

year 2012 through 2016. It appears that a principal industry trade group has proposed 

reducing the stringency of the proposed fuel economy standards for model year 2012-

1015, arguing that, as currently proposed the standards do not meet EISA’s requirement 

for the standards to increase “ratably.” See Alliance of Automobile Manufacturers 

(Alliance) Document ID EPA-HQ-OAR-2009-0472-6952.1. CARB strongly opposes the 

Alliance proposal. 

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California committed to adopt the national program for model years 2012-2016 with the 

understanding that it would provide equivalent or better overall greenhouse gas 

reductions nationwide than California’s own program coupled with its adopting sister 

states; the Alliance proposal threatens that equation. First, the proposed fuel economy and 

greenhouse gas requirements were designed to establish a national program with a 

consistent and harmonized approach that would reduce greenhouse gas emissions and 

improve fuel economy from light-duty vehicles. Because the Alliance is also 

recommending that EPA’s GHG standards be simultaneously stepped, the greenhouse gas 

reductions projected for the national program would be significantly reduced. Second, the 

proposed fuel economy and greenhouse gas requirements were established after a joint 

effort by both agencies to determine standards that were technically feasible and costeffective in the timeframe proposed. We do not believe that a case has been made to 

refute the agencies’ analyses. These and other Alliance recommendations need careful 

review to ensure that they do not reduce the stringency and consequent cumulative 

greenhouse gas reductions California expected in committing to the National 

Program. [OAR-2009-0472-7189.1, p.2] 

[CARB also submitted these comments as testimony at the Los Angeles public hearing. 

See docket number OAR-2009-0472-7283, pp. 21-27] 

International Council on Clean Transportation 

The technical analyses conducted by EPA and NHTSA are sound and demonstrate that 

the proposed standards are feasible and the benefits of the rule far outweigh the costs. 

The analytical framework also provides a good base for further reductions in fuel 

consumption and greenhouse gas emissions beyond 2016. 

US Steel Corporation 

Consider the regulation targets for the year 2016 for both agencies. The target for EPA is 

250 g/mile CO2 fleet average, equivalent to 35.5 mpg with allowable air conditioning 

and flex fuel credits. The NHTSA combined fleet target is roughly equivalent to EPA’s 

standard and requires 34.1 mpg combined fleet average, but without air conditioning 

credits. Should carmakers comply with these rules, the previous goal of Congress (2007 

CAFE Law previously specifying 35 mpg by 2020) will have been met four years ahead 

of schedule. This acceleration places the car companies in a difficult position to satisfy 

the regulations by making major technical and manufacturing decisions in order to be 

compliant, some of which could have negative consequences. The National Program 

similarly compresses the time frame for steel suppliers and other materials suppliers to 

develop and produce those new materials, such as the required grades of advanced highstrength steels and ultra high-strength steels, which will help build the required 

improvements into cars and trucks during this period. 

The overly aggressive schedule proposed by this joint NPRM may cause car companies 

to select low density materials at a faster rate than would be the case if a more extended 

time period were applied. The harm suffered by the steel industry, the risk to national 

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EPA Response to Comments 

energy security through acceleration in the use of high-energy materials for vehicle mass 

reduction, in addition to the harm to the environment and the harm to the economy could 

be accelerated by this decision. The risk of selecting high energy use and high CO2 

emissions materials to adhere to the standard during the 2012-2016 time period would be 

significant. Our recommendation is to consider reducing the rate of improvement to the 

time frame originally defined by Congress (35 mpg by 2020) or to ensure that appropriate 

credits, such as those which may be associated with low energy, low emissions materials 

(such as steel) in the manufacturing of the vehicle be included in the CAFE/emissions 

formulae. In this way car companies will have additional time to work with suppliers and 

their own development teams to acquire the best technologies for the required 

improvements in fuel economy. [OAR-2009-0472-7197.1, p.7] 

University of Pennsylvania Environmental Law Project 

We agree with the EPA’s response under the Proposed Rule in setting strict minimum 

compliance levels for carbon dioxide (CO2) emissions. [OAR-2009-0472-7286.1, p. 11] 

Sack, Emily 

I urge you to find the strongest possible regulations to protect, to begin to reduce the 

devastating impact that the pollution -- the pollutants have had on our air and our water 

and our quality of life. [EPA-HQ-OAR-2009-0472-4621, p.157] 

[See Docket Number EPA-HQ-OAR-2009-0472-4621, pp.154-157 for detailed 

comments] 

EPA Response: 

As discussed in the proposal, section 202(a)(1) provides EPA broad discretion in setting 

emissions standards for new motor vehicles. 74 FR 49454, 49464-5 (September 28, 

2009). 

Section 202 (a) (1) of the Clean Air Act (CAA) states that “the Administrator shall by 

regulation prescribe (and from time to time revise)...standards applicable to the emission 

of any air pollutant from any class or classes of new motor vehicles ..., which in his 

judgment cause, or contribute to, air pollution which may reasonably be anticipated to 

endanger public health or welfare.” If EPA makes the appropriate endangerment and 

cause or contribute findings, then section 202(a) authorizes EPA to issue standards 

applicable to emissions of those pollutants. 

 

Any standards under CAA section 202(a)(1) “shall be applicable to such vehicles ... for 

their useful life.” Emission standards set by the EPA under CAA section 202(a)(1) are 

technology-based, as the levels chosen must be premised on a finding of technological 

feasibility. Thus, standards promulgated under CAA section 202(a) are to take effect 

only “after providing such period as the Administrator finds necessary to permit the 

development and application of the requisite technology, giving appropriate consideration 

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EPA CO2 Standards 

to the cost of compliance within such period” (section 202 (a)(2); see also NRDC v. EPA, 

655 F. 2d 318, 322 (D.C. Cir. 1981)). EPA is afforded considerable discretion under 

section 202(a) when assessing issues of technical feasibility and availability of lead time 

to implement new technology. Such determinations are “subject to the restraints of 

reasonableness”, which “does not open the door to ‘crystal ball’ inquiry.” NRDC, 655 F. 

2d at 328, quoting International Harvester Co. v. Ruckelshaus, 478 F. 2d 615, 629 (D.C. 

Cir. 1973). Also see NRDC, 655 F. 2d at 333-34. In developing such technology-based 

standards, EPA has the discretion to consider different standards for appropriate 

groupings of vehicles (“class or classes of new motor vehicles”), or a single standard for 

a larger grouping of motor vehicles (NRDC, 655 F. 2d at 338). 

Although standards under CAA section 202(a)(1) are technology-based, they are not 

based exclusively on technological capability. EPA has the discretion to consider and 

weigh various factors along with technological feasibility, such as the cost of compliance 

(see section 202(a) (2)), lead time necessary for compliance (section 202(a)(2)), safety 

(see NRDC, 655 F. 2d at 336 n. 31) and other impacts on consumers, and energy impacts 

associated with use of the technology. See George E. Warren Corp. v. EPA, 159 F.3d 

616, 623-624 (D.C. Cir. 1998) (ordinarily permissible for EPA to consider factors not 

specifically enumerated in the Act). See also Entergy Corp. v. Riverkeeper, Inc., 129 

S.Ct. 1498, 1508-09 (2009) (congressional silence did not bar EPA from employing costbenefit analysis under Clean Water Act absent some other clear indication that such 

analysis was prohibited; rather, silence indicated discretion to use or not use such an 

approach as the agency deems appropriate). 

In addition, EPA has clear authority to set standards under CAA section 202(a) that are 

technology forcing when EPA considers that to be appropriate, but is not required to do 

so (as compared to standards set under provisions such as section 202(a)(3) and section 

213(a)(3)). EPA has interpreted a similar statutory provision, CAA section 231, as 

follows: 

While the statutory language of section 231 is not identical to other provisions in 

title II of the CAA that direct EPA to establish technology-based standards for 

various types of engines, EPA interprets its authority under section 231 to be 

somewhat similar to those provisions that require us to identify a reasonable 

balance of specified emissions reduction, cost, safety, noise, and other factors. 

See, e.g., Husqvarna AB v. EPA, 254 F.3d 195 (DC Cir. 2001) (upholding EPA’s 

promulgation of technology-based standards for small non-road engines under 

section 213(a)(3) of the CAA). However, EPA is not compelled under section 231 

to obtain the ‘‘greatest degree of emission reduction achievable’’ as per sections 

213 and 202 of the CAA, and so EPA does not interpret the Act as requiring the 

agency to give subordinate status to factors such as cost, safety, and noise in 

determining what standards are reasonable for aircraft engines. Rather, EPA has 

greater flexibility under section 231 in determining what standard is most 

reasonable for aircraft engines, and is not required to achieve a ‘‘technology 

forcing’’ result.2

 

 

2

 70 FR 69664, 69676, November 17, 2005. 

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EPA Response to Comments 

This interpretation was upheld as reasonable in NACAA v. EPA, (489 F.3d 1221, 1230 

(D.C. Cir. 2007)). CAA section 202(a) does not specify the degree of weight to apply to 

each factor, and EPA accordingly has discretion in choosing an appropriate balance 

among factors. See Sierra Club v. EPA, 325 F.3d 374, 378 (D.C. Cir. 2003) (even where 

a provision is technology-forcing, the provision “does not resolve how the Administrator 

should weigh all [the statutory] factors in the process of finding the 'greatest emission 

reduction achievable’”). Also see Husqvarna AB v. EPA, 254 F. 3d 195, 200 (D.C. Cir. 

2001) (great discretion to balance statutory factors in considering level of technologybased standard, and statutory requirement “to [give appropriate] consideration to the cost 

of applying ... technology” does not mandate a specific method of cost analysis); see also 

Hercules Inc. v. EPA, 598 F. 2d 91, 106 (D.C. Cir. 1978) (“In reviewing a numerical 

standard we must ask whether the agency’s numbers are within a zone of reasonableness, 

not whether its numbers are precisely right”); Permian Basin Area Rate Cases, 390 U.S. 

747, 797 (1968) (same); Federal Power Commission v. Conway Corp., 426 U.S. 271, 278 

(1976) (same); Exxon Mobil Gas Marketing Co. v. FERC, 297 F. 3d 1071, 1084 (D.C. 

Cir. 2002) (same). 

As described above, EPA has broad discretion in determining the appropriate standards to 

adopt under section 202(a)(1), based on a reasonable consideration and balancing of 

various factors relevant under that provision. As discussed in the preamble, including 

section III.D., EPA did consider and balance all of the factors discussed by commenters – 

the GHG reductions achieved by the various proposed and alternative standards, the 

technology to achieve such standards, lead time, cost of achieving the standards, as well 

as other factors such as safety impacts. EPA explained that the final standards will 

achieve very large and significant reductions in GHGs, as well as very significant fuel 

savings. EPA identified a technology pathway by which manufacturers could achieve 

these reductions, modeling in detail each manufacturer's fleet of cars and trucks. The 

technology pathway calls for the widespread introduction across the fleet of several 

different kinds of technology that are currently available but with much more limited 

usage, as well as an expectation of a limited use of some more costly technology, such as 

HEVs. For the near term model years at issue in this rulemaking, EPA expects that there 

will only be a very limited use of advanced technologies such as EVs and PHEVs. EPA 

evaluated the cost of this spread in technology and found it reasonable both from the 

perspective of costs per vehicle as well as the total benefits of the rule far outweighing 

the total costs. Lead time is a critical consideration and EPA determined that there is 

adequate lead time to employ the financial, engineering, and other resources needed to 

achieve the standards, recognizing that a significant portion of these human and capital 

resources would need to be expended during the next few years. Lead time is somewhat 

constrained for these model years, as it is now 2010 and MY 2012 is only a number of 

months away. The farthest model year, 2016, also is not many years from now, given the 

time needed for redesigning cars and trucks for new production. EPA also took into 

account that the automobile manufacturing industry has been and continues to face 

serious economic and other constraints, stemming from the recent economic problems in 

the U.S. and around the world. This is an important context to EPA’s evaluations of cost 

and lead time considerations. 

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EPA CO2 Standards 

The final standards will achieve very significant reductions in GHG emissions and fuel 

savings, the technology to achieve these reductions is identified and commercially 

available, and the costs are reasonable. EPA also recognizes that the standards will be 

difficult for the manufacturers to achieve and present major hurdles for them to 

overcome. While the technology is generally well understood and can be implemented 

over these model years, the lead time to do so is relatively short and the capital and 

human resources that must be employed are large, especially in the next few years, and 

must occur in the context of current serious economic strain on this industry. 

Considering all of these factors, EPA determined that the final standards are a reasonable 

and appropriate balance of the relevant factors under section 202(a)(1). 

US Steel commented that the rate of improvement associated with the final standards 

could force the use of low density, high energy (required for production) materials before 

the steel industry had time to ramp up the production capacity of high strength, low 

energy (required in production) steel. We do not agree that the rate at which the final 

standards require improvement will result in the permanent reduction in the use of high 

strength steel. First, the overall weight reduction projected for the final standards is only 

4%. As discussed in the Joint TSD, several manufacturers have already announced plans 

to achieve weight reductions approaching this level. Second, several manufacturers 

already utilize high strength steel components, indicating some production capacity and 

general engineering awareness of its benefits. Third, given this awareness, we do not 

believe that it is likely that manufacturers would lock themselves into vehicle designs 

which precluded future use of the benefits of high strength steel, even if they should 

decide to use another material in the very near term due to capacity constraints. 

US Steel specifically suggested that we slow the rate of improvement in the fuel economy 

and CO2 standards to that described in EISA. Again, we do not agree that this would be 

acceptable. First, the 35 mpg fleet-wide fuel economy mentioned in EISA is a minimum 

requirement, not a mandated target. Second, with the exception of several smaller 

manufacturers, the final standards are not projected to require the substantial use of 

hybrid or diesel technology. To promulgate more relaxed standards would reduce the use 

of much more conventional technology. If manufacturers are concerned about supply of 

high strength steel, which is US Steel’s main concern, we believe that manufacturers 

have several options available to compensate, one being increased use of hybrid and 

diesel technology in market segments where they have experience with these 

technologies and where consumer acceptance has been demonstrated. 

EPA also considered standards that were less stringent and more stringent than those 

adopted. EPA took a similar approach in evaluating these alternative standards. EPA 

considered and balanced all of the statutorily relevant factors, comparing and contrasting 

these to the final standards. For example, EPA rejected an alternative of more stringent 

standards that would achieve an average 6% per year increase. EPA’s rejection of the 6% 

alternative was based largely on concerns over the adequacy of the lead time in a context 

of a significant increase in technology and costs, and a significant increase in the risk of 

non-compliance by manufacturers. These real world concerns indicate that the 6% per 

year alternative is not an appropriate standard for the MY 2012-2016 time frame, even 

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EPA Response to Comments 

though it would by definition achieve greater GHG reductions and fuel savings than the 

final standards. 

With respect to the 6 percent per year standards, the levels of requisite control technology 

increased substantially relative to those under the final standards, as would be expected. 

Industry-wide, the largest increase was a 25 percent increase in the application of startstop technology and 13-17 percent increases in the use of gasoline direct injection 

engines, turbo charging and dual clutch transmissions. Our projections for BMW, 

Porsche, Tata and Volkswagen continue to show they are unable to comply with the CO2

standards in 2016, so our projections for these manufacturers do not differ relative to the 

final standards, though the amount of short-fall for each firm increases significantly, by 

an additional 20 g/mi CO2 per firm. However, Ford and Mitsubishi join this list. Five 

manufacturers are projected to need to increase their use of start-stop technology by at 

least 30 percent. 

The 6% per year alternative represents a significant fleetwide increase in both the 

technology required and the overall costs compared to the final standards. In absolute 

percent increases in the technology penetration, compared to the final standards the 6% 

per year alternative requires for the industry as a whole: an 18% increase in GDI fuel 

systems, an 11% increase in turbo-downsize systems, a 6% increase in dual-clutch 

automated manual transmissions (DCT), and a 9% increase in start-stop systems. For a 

number of manufacturers the expected increase in technology is greater, as noted in the 

paragraph above. For the industry as a whole, the per-vehicle cost increase for the 6% 

per year alternative is nearly $500 greater than the per vehicle cost of the final standard. 

On average this is a 50% increase in costs compared to the final standards. At the same 

time, CO2 emissions would be reduced by about 8%, compared to the 250 g/mi target 

level. These incremental costs are out of proportion to those of the final standards. 

As noted in the preamble and earlier in this response, EPA’s OMEGA model predicts that 

for model year 2016, Ford, Mitsubishi, Mercedes, BMW, Volkswagen, Jaguar-Landover, 

and Porsche do not meet their target under the 6 percent per year scenario. In addition, 

Chrysler, General Motors, Suzuki and Nissan all are within 2 grams/mi CO2 of 

maximizing the applicable technology allowed under EPA’s OMEGA model – that is, 

these companies have almost no head-room for compliance. In total, these 11 companies 

represent more than 58 percent of total 2016 projected U.S. light-duty vehicle sales. This 

provides a strong indication that the 6 percent per year standard is much more stringent 

than the final standards, and presents a significant risk of non-compliance for many firms, 

including four of the seven largest firms by U.S. sales. 

These technology and cost increases are significant, given the amount of lead-time 

between now and model years 2012-2016. In order to achieve the levels of technology 

penetration for the final standards, the industry needs to invest significant capital and 

product development resources right away, in particular for the 2012 and 2013 model 

year, which is only 2-3 years from now. For the 2014-2016 MY time frames, significant 

product development and capital investments will need to occur over the next 2-3 years in 

order to be ready for launching these new products for those model years. Thus, a major 

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EPA CO2 Standards 

part of the required capital and resource investment will need to occur now and over the 

next few years, under the final standards. EPA believes that the final rule (a target of 250 

gram/mile in MY 2016) already requires significant investment and product development 

costs for the industry, focused on the next few years. 

It is important to note, as discussed in the preamble, as well as in the Joint Technical 

Support Document and the EPA Regulatory Impact Analysis document, the average 

model year 2016 per-vehicle cost increase of roughly $950 includes an estimate of both 

the increase in capital investments by the auto companies and the suppliers as well as the 

increase in product development costs. These costs can be significant, especially as they 

must occur over the next 2-3 years. Both the domestic and transplant auto firms, as well 

as the domestic and world-wide automotive supplier base, is experiencing one of the most 

difficult markets in the U.S. and internationally that has been seen in the past 30 years. 

One major impact of the global downturn in the automotive industry and certainly in the 

U.S. is the significant reduction in product development engineers and staffs, as well as a 

tightening of the credit markets which allow auto firms and suppliers to make the nearterm capital investments necessary to bring new technology into production. The 6% per 

year alternative standard would impose significantly increased pressure on capital and 

other resources, indicating that it is too stringent for this time frame, given both the 

relatively limited amount of lead-time between now and model years 2012-2016, the 

need for much of these resources over the next few years, as well as the current financial 

and related circumstances of the automotive industry. EPA is not concluding that the 6% 

per year alternative standards are technologically infeasible, but EPA believes such 

standards for this time frame would be overly stringent given the significant strain it 

would place on the resources of the industry under current conditions. EPA believes this 

degree of stringency is not warranted at this time. Therefore, EPA does not believe the 

6% per year alternative would be an appropriate balance of various relevant factors for 

model years 2012-1016. 

There is particular sensitivity to predicating these standards on more aggressive 

penetration of strong hybrid technologies. The more stringent alternatives are all 

projected to necessitate more extensive use of hybrid technologies. Several hybrid 

technologies have already been commercially demonstrated and their use could clearly be 

expanded. (Several manufacturers may even require extensive use of hybrid technology 

to meet the final standards due to certain characteristics of their vehicles which lead to 

unusually high fuel consumption and CO2 emissions.) However, while a couple of 

manufacturers have extensive experience with high volume hybrid production and use in 

smaller cars, some large volume manufacturers have minimal experience. No 

manufacturer has extensive experience across all of the market segments believed to be 

suitable for hybridization. Current world-wide production capacity for hybrid 

components is relatively small. Thus, the application of hybrid technology to a 

significant fraction of U.S. sales in the 2012-2016 time frame would require extensive 

new resources at every level: design, component production, vehicle integration, and 

vehicle production. In addition, since the electric components and batteries in a fully 

optimized hybrid design (capable of achieving the CO2 emission reductions projected in 

the Joint TSD) usually require significant changes to the vehicle design, hybrids will 

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EPA Response to Comments 

likely require separate safety assessments, increasing the need for engineering and testing 

resources during a time of economic challenge. 

Moreover, one of the key components of the hybrid technology is the battery or other 

type of device to store energy and battery technology is developing rapidly. Establishing 

MY 2012-2016 standards which necessitate extensive use of hybrid technology each 

model year would 1) require dramatic capital investment in plants needed to produce the 

hybrid components, and 2) would commit manufacturers to large investments in specific 

battery technologies which may not be the technology of choice in just a few years. We 

believe that it is much more prudent to give this particular technology a few more years 

of development before basing standards on its widespread use. We believe that the final 

standards are sufficiently stringent that hybrid technology will still be used on significant 

numbers of vehicles and encourage the continued development of this technology. 

All of these factors apply even more strongly to the more advanced plug-in hybrid and 

fully electric vehicle technologies. These vehicles require much larger battery capacity 

and are much more likely to require use of the new lithium-based materials. Significant 

application of these two technologies would not only require substantial increases in 

lithium battery production, but would require entirely new mining production capacity as 

well. 

In short, EPA believes that it has made an informed and reasoned choice in rejecting the 

6% alternative, and does not accept the commenter’s characterization that the basis for 

the choice is unsubstantiated or otherwise arbitrary. 

Certain commenters rejected EPA’s approach to considering and balancing the relevant 

factors under section 202(a)(1). They argued that this approach was ad hoc and narrow, 

and that EPA should announce and apply a different approach to standard setting for this 

rulemaking. In their view, EPA should first determine a specific goal of GHG 

reductions and oil savings, based on an assessment of national needs, and then apply 

considerations of technological feasibility and cost, in order to be as technology forcing 

as possible or practicable. One suggestion was to have a quantitative goal – identify the 

country's goal for reducing GHGs and then assign a proportionate share to the 

transportation sector as a default position. Commenters also suggested that EPA should 

assign more priority to achieving an environmental goal and thereby prioritizing public 

health and welfare, placing that above economic or other considerations. Commenters 

suggested this was required under both “the agency’s ... responsibility to set protective 

standards consistent with its statutory mandate” (Public Citizen) and with the CAA’s 

mandate to “be as technology-forcing as possible” (Public Citizen; see also Sierra Club). 

Other commenters suggested that the decision making criteria should call for a standard 

no less stringent than one that maximizes net benefits, or that this should be a presumed 

minimum. 

The comments appear to mischaracterize CAA section 202 (a) (1), and the discretion 

Congress provided to EPA under that provision. Commenters appear to read this 

provision as a mandate from Congress that EPA place the greatest emphasis on achieving 

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EPA CO2 Standards 

a desired environmental goal, with secondary emphasis on other factors such as economic 

considerations or considerations of lead time and technological feasibility. However, 

Congress clearly provided very broad discretion to EPA and did not direct its discretion 

in the ways suggested. For example, section 202(a) is not a provision where reducing 

risk is the only or the highest priority assigned by Congress. Compare, e.g., CAA 

sections 109(b) and 112(f)(2). It is also not a provision where Congress mandated a 

certain minimum degree of technology or emissions reduction. See CAA section 

112(d)(3). It is not a provision where Congress directed EPA to be technology forcing 

and achieve the greatest achievable reductions from technology that will be available in 

the future. See CAA sections 202(a)(3) and 213(a)(3). Instead, Congress referred to 

consideration of available technology, its effectiveness and cost, the lead time necessary 

for compliance. See generally 74 FR at 49464-65. Although section 202 (a) (1) 

standards may be technology-forcing, they are not required to be. 74 FR at 49464-65. 

As discussed above with respect to section 231(a), CAA section 202(a)(1) does not 

specify the degree of weight to apply to each factor, and EPA accordingly has discretion 

in choosing an appropriate balance among the relevant factors. Thus EPA rejects that the 

approach taken in this rule of considering and balancing the various relevant factors is 

inconsistent with the discretion provided by Congress under CAA section 202(a)(1). 

EPA also disagrees that a more determinative or approach to standard setting or more 

specific or objective decision making criteria are either required or called for in this 

rulemaking. For example, EPA does not believe it is appropriate for this rulemaking to 

try and determine a free standing national goal for reducing GHGs and saving oil, and 

either assigning a specific share to these light-duty sources or using the goal as a measure 

of some sorts for standard setting. In the relatively short timeframe for this rulemaking, it 

would be unrealistic to try and develop such a goal, given the great complexity and 

national input that this would involve. In addition, it is not at all clear that for this 

specific rulemaking that such a goal would be of any more use than a more general and 

qualitative goal of achieving significant reductions, given the recognized need for 

significant reductions and taking into account the limited scope of the near-term model 

years covered by this rulemaking. In the context of this short term rulemaking, covering 

just the next handful of model years, with limited lead time to implement changes in 

technology, EPA does not believe that a more specific and quantitative goal of longer 

term GHG reductions for the nation and this sector would provide any better guidance to 

the agency than the more qualitative but no less important goal EPA has employed - 

achieving significant reductions by moving the industry to the point where available nearterm technology is broadly employed across the fleet, over the next few model years, 

taking into consideration the lead time needs of the industry and other factors. 

EPA also disagrees that this amounts to a failure to place the proper priority on achieving 

the health and welfare protection called for by the CAA. CAA Section 202(a)(1) 

provides the guide to Congress’ intent on this issue, and EPA has employed the broad 

discretion provided by that provision to aim for and achieve very significant reductions in 

GHGs, after taking careful consideration of the factors relevant under that provision, as 

described above. This approach is fully consistent with CAA section 202(a)(1), and 

EPA’s consideration and balancing of the factors in this rulemaking gives full 

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EPA Response to Comments 

consideration of the need to achieve significant GHG reductions to help reduce the risk to 

public health and welfare from global climate change. 

EPA also disagrees that it should use specific criteria for considering cost, using the 

maximization of net benefits as a minimum. As explained above and in the preamble, 

EPA has very good reasons for rejecting the 6% alternative, and that alternative is still 

significantly below the level that NHTSA has estimated would maximize net benefits. 

The alternative standards evaluated by NHTSA as providing the maximum net benefits 

(given all of the market, technological, economic, and other inputs to the agencies’ 

analyses) are even more stringent and less supportable than the 6% alternative rejected by 

EPA. While the relationship of marginal costs to marginal benefits is certainly a factor 

for EPA to consider, and EPA has considered it, the currently-estimated relationship of 

marginal costs to benefits does not, by itself, adequately determine the appropriate 

balance of the several factors EPA must consider, such as consideration of lead time, 

overall cost, and technological feasibility. It also assumes that all costs and befits have 

been fully and accurately identified, and that is certainly not the case. Even so, per 

NHTSA’s analysis of this scenario, the incremental cost of the maximum net benefit 

scenario exceeds that of the final standards by $700 per car for only a 2.5 mpg 

improvement and $1100 per truck for a two mpg improvement. These incremental costs 

are far out of proportion to those of the final standards. Numerous manufacturers were 

projected to be required to exceed the 15% cap on hybridization, particularly for their 

truck lines. EPA believes it is better in this rulemaking to consider this factor as one of 

several factors, but not to consider it as a single or predominant criterion for setting the 

standards in this rulemaking under CAA section 202(a)(1). 

As discussed above, EPA is not required under CAA section 202(a)(1) to set standards 

that are technology forcing, as under CAA section 202(a)(3) or section 213(a)(3). 

However, the final standards are readily justifiable under CAA provisions which are 

technology-forcing (allowing considerations of future advances in emission control 

capability as well as those already in existence and application). Neither CAA section 

202 (a) (1) nor provisions which are explicitly technology-forcing (e.g. section CAA 202 

(a)(3) requiring “the greatest degree of emission reduction achievable”) specify the 

weight to accord each relevant decision factor, leaving EPA with great discretion in 

determining an appropriate balance. See Sierra Club v. EPA, 325 F. 3d 374, 378 (D.C. 

Cir. 2003). And although the commenters are correct that the statute’s environmental 

goals are a dominant consideration in weighing the relevant factors, Husqvarna AB v. 

EPA, 254 F. 3d 195, 200 (D.C. Cir. 2001), EPA retains great discretion to weigh the 

relevant factors so long as its resolution is within a zone of reasonable values. See, e.g. 

Hercules Inc. v. EPA, 598 F. 2d 91, 106 (D.C. Cir. 1978). As discussed in detail in 

section III.D. of the preamble to the final rule (and in particular, in sections III.D.6 and 

7), the final standards are projected to require very significant penetration of technologies 

throughout the fleet and already raise challenging issues of sufficient lead time at the 

selected level of stringency. As further discussed in the preamble and in later responses 

in this comment response section, EPA reasonably considers more stringent standards to 

be inappropriate 

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EPA CO2 Standards 

Several commenters were also concerned that the approach taken in this rulemaking 

would limit EPA’s discretion in future rulemakings for this or other sectors, and 

recommended that EPA announce its approach for future rulemakings. As described 

above, EPA does not believe it is appropriate to identify a more precise or quantitative 

approach to standard setting for this rulemaking. These same reasons lead EPA to not 

announce such an approach for a future rulemaking concerning later light-duty model 

years. The discussion above and in the preamble makes it clear that the specific facts 

before the agency are critical in determining the appropriate balance of the relevant 

factors. It is useful to preserve the discretion to address the issues that must be 

considered in standard setting under section 202(a)(1) without a predetermined approach. 

That preserves EPA’s discretion to take into account the detailed circumstances before it. 

For example, if longer lead time is involved in a future rulemaking this could lead to 

consideration of greater changes in technology, leading to greater reductions. Section 201 

(a) (1) provides EPA great flexibility to tailor standards to circumstances, and EPA sees 

no advantage in a priori limiting that desirable degree of regulatory discretion. 

Several commenters suggest that the proposed standards were insufficiently stringent due 

to the public's demonstrated shift towards smaller vehicles and away from trucks. 

However, as fuel prices have stabilized at levels below $3 per gallon, truck sales have 

rebounded to some extent and sales of hybrids have fallen as a percentage of overall sales 

from their highs in 2008. Thus, it is not prudent to base long term purchasing trends on 

potentially short term market perturbations. See 74 FR at 14317-318 (March 30, 2009) 

(inappropriate to estimate future price of petroleum based on then-current high market 

fluctuations). We believe that the technology needed to meet the final standards will 

provide fuel savings which more than pay for itself over the life of the vehicle under 

essentially any realistic future fuel price scenario. Again, we also believe that the 

technological improvements which will occur over the 2012-2016 time period will 

provide a solid foundation for further improvements in the future. 

One commenter suggested that standards which reflected 5% per year reductions in CO2 

emissions should have been analyzed and potentially selected. Of course, numerous 

additional alternative standards can be identified in addition to those analyzed. We 

believe that standards beyond those being promulgated would have pushed most 

manufacturers to greater hybrid use. For example, per NHTSA’s analysis of this 

scenario, the incremental cost of the 5% per year reduction scenario exceeds that of the 

final standards by $200 per car for only a 1.1 mpg improvement and $400 per truck for a 

0.8 mpg improvement. These incremental costs are much greater than those of the final 

standards. From this NHTSA analysis, it appears that the standards being promulgated in 

this rule require the use of nearly all of the non-hybrid and non-diesel technology 

projected to be available in this timeframe for many of the large volume manufacturers. 

While hybrid and diesel technologies are technically feasible and have been 

commercialized in several applications, the investment costs for these technologies far 

exceeds those of the other technologies. The technology projected to be required to 

enable compliance with the final standards already requires significant new investment 

for dual clutch transmissions and start stop systems. Given the current economic climate, 

we are concerned that manufacturers and major suppliers may not have sufficient capital 

3-69 
EPA Response to Comments 

to build the capacity for large volumes of electric motors, batteries, transmission control 

systems, diesel engines, nor the engineering resources to begin designing these systems 

essentially immediately. We believe that the substantive addition of these major 

technologies is best left to the post-2016 time period. 

We appreciate the comments mentioning concern about the need to make near term 

decisions about the use of weight saving materials. However, the projected reductions in 

vehicle mass projected for the final standards are relatively small (e.g., 4% on average, 

although some vehicles are projected to apply more mass reduction and some less). 

While manufacturers are free to choose from a variety of technology with which to meet 

the final standards, we believe that such weight reductions can be achieved by choosing 

methods which will prove to be beneficial beyond 2016. 

3.3.1 2016 Standard and selection of proposed standards versus 4% per year and 

6% per year alternative standards 

Organization: Center for Biological Diversity 

Toyota Motor North America 

New York State Department of Transportation (NYSDOT) 

Consumer Federation of America 

Comment:

Center for Biological Diversity 

III. The Proposed Rule Sets Impermissibly Low Mileage and GHG Emission Standards 

By Arbitrarily and Capriciously Undervaluing the Benefits and Overvaluing the Costs of 

More Stringent Standards and Failing to Adhere to the Overriding Goal of Conserving 

Energy 

When Congress enacted EPCA, it specified its goals: to decrease the nation’s dependence 

on foreign oil imports, to enhance national security and to achieve the efficient utilization 

of scarce resources. Center for Biological Diversity, 508 F.3d at 514. To achieve these 

goals, EPCA expressly demands that NHTSA set the maximum feasible fuel economy 

standards. 49 U.S.C. § 32902(a). In doing so, NHTSA must weigh four factors: 

technological feasibility, economic practicability, the effect of other motor vehicle 

standards on fuel economy, and the need of the United States to conserve energy. 49 

U.S.C. § 32902(f). In balancing these factors, NHTSA “cannot set fuel economy 

standards that are contrary to Congress’s purpose in enacting the EPCA – energy 

conservation,” it cannot act arbitrarily and capriciously; it cannot advance conclusions 

unsupported by the evidence; if it conducts cost-benefit analyses, it may not assign values 

of zero to benefits that can be ascertained within a range; and it cannot bias its costbenefit analysis. Center for Biological Diversity, 508 F.3d at 531, 534. As set forth 

above, Section 202(a) of the Clean Air Act requires a similar analysis, setting control 

standards no later than the availability of control technology allows, while giving 

appropriate consideration to compliance costs. The Proposed Rule fails to meet the 

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requirements of the law because none of the relevant factors support its conclusions. 

[OAR-2009-0472-7265.1, p. 5] 

A. Technological Feasibility Supports More Stringent Standards 

The Proposed Rule admits that “all” of the technology to improve fuel efficiency is 

commercially available today: 

NHTSA’s and EPA’s technology assessment indicates there is a wide range of 

technologies available for manufacturers to consider in upgrading vehicles to reduce 

GHG emissions and improve fuel economy . . . All of these technologies are already 

available today, and EPA’s and NHTSA’s assessment is that manufacturers would be 

able to meet the proposed standards through more widespread use of these technologies 

across the fleet. 74 Fed. Reg. 49470 (emphasis added). 

This is a stunning conclusion, as it means that if deployed, technology already in use 

today could allow the U.S. light-duty vehicle fleet to meet the Agencies’ 2016 mileage 

standard of 34.1 miles per gallon and greenhouse gas emission standards of 250 grams 

per mile in 2009, seven years earlier than here projected. Plainly, one of the four factors 

NHTSA must consider – technological feasibility – points in only one direction: much 

more stringent standards. Indeed, the Agencies could not defend any claim that 

technological constraints prevent the achievement of much higher standards. This is so 

because the average fuel economy of the vehicle fleets presently on the roads in the 

European Union (at 41.8 mpg in 2008) and Japan (at 40.6 in 2007) already far exceed the 

standards the Agencies are proposing for 2016.6 China’s fleet, at 32.9 mpg in 2008, and 

South Korea’s, at 31.0 mpg in 2008, are currently not far behind the U.S. proposal for 

2016. The following graph quickly illustrates the point: [See OAR-2009-0472-7265.1, p. 

7 for the graph] [OAR-2009-0472-7265.1, pp. 5-7] [See OAR-2009-0472-7265.1, pp. 5-

8 for a detailed discussion of technological feasibility.] 

D. The Need of the United States to Conserve Energy Supports More Stringent Standards 

It should go without saying that the last of the factors to be considered under EPCA, the 

United States’ need to conserve energy, supports setting more stringent mileage and 

tailpipe GHG emission standards. “Motor vehicles are the second largest greenhouse gasemitting sector in the U.S., after electricity generation, and accounted for 24 percent of 

total U.S. GHG emissions in 2006.” Proposed Rule, 74 Fed. Reg. 49632. The light duty 

vehicles that are the subject of this rulemaking account for fully 40% of all U.S. oil 

consumption. Id., 74 Fed. Reg. 49459. Increasing mileage standards for this vehicle fleet 

is the single most effective and quickest available step the U.S. can take to conserve 

energy and to reduce the U.S. dependence on foreign oil, and also has an immediate and 

highly significant effect on total U.S. GHG emissions. Indeed, it would be difficult to 

overemphasize the critical impact on vital national interests that could be achieved if the 

Proposed Rule would simply set its 2016 standards at the fuel efficiency and GHG 

emission reduction levels the European Union or Japan implement today.[OAR-2009-

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EPA Response to Comments 

0472-7265.1, pp. 19-20] [See OAR-2009-0472-7265.1, pp. 20-25 for an extensive 

discussion of this issue.] 

Toyota Motor North America 

In general, the overall level of the standards in 2016 model year is consistent with 

Toyota's expectation, the agreements signed last May, and the joint Notice of Intent 

(NOI) published last spring. Additional comments and responses to specific questions 

posed by the agencies are covered below. Where appropriate, we have identified to which 

agency's portion of the joint proposal our comments are directed. [OAR-2009-0472-7291, 

p.6] 

In general, the proposed standards in 2016 model year (a new vehicle fleet-wide level of 

250 grams of C02 per mile - equivalent to 35.5 mile per gallon) are consistent with 

Toyota's expectation, the agreements signed last May, and the joint Notice of Intent 

(NOI) published last spring. While meeting these levels will be a serious challenge for 

our engineers and product planners, we remain committed to the agreement and will 

make every effort to meet the challenge. [OAR-2009-0472-7291, p.7] 

New York State Department of Transportation 

The baseline condition used in the analysis of alternatives for the previous CAFE 

proposals was based on manufacturers' confidential plans for each model year, whereas 

the baseline in this proposal is based on each manufacturer's actual MY 2008 fleet. We 

agree that this approach will result in more complete market data and is more transparent 

than relying on manufacturers' confidential plans. It is also illustrative. While the results 

vary somewhat among manufacturers, the current MY 2011 baseline fuel economy is 

slightly better than the baseline fuel economy that was assumed in the MY 2011 final 

rule. This fact indicates that the auto industry as a whole is capable of achieving progress 

in improving fuel economy more rapidly than the rate that would be required by the 

proposed rule. [OAR-2009-0472-7531.1, p.2] 

Since the actual MY 2011 baseline is more fuel efficient than the previously assumed 

baseline, it is difficult to understand why the fuel economy projections for many of the 

alternatives that were considered in developing this proposed rule are less stringent than 

similar alternatives that were evaluated in the development of the MY 2011-2015 

standards. For example, the 'Total Costs = Total Benefits (TCTB)' alternative that was 

evaluated in the previous CAFE proposal was projected to result in a required fuel 

economy of 43.3 mpg for MY 2015 passenger vehicles and 33.1 mpg for MY 2015 light 

trucks. Conversely, the TCTB alternative in today's proposal is projected to only achieve 

40.8 mpg for MY 2015 passenger vehicles and 30.9 mpg for MY 2015 light trucks. We 

request that NHTSA and EPA provide an explanation as to why this 'backsliding' of the 

effectiveness of similar alternatives has occurred between the 2008 and 2009 proposals. 

[OAR-2009-0472-7531.1, p.2] 

Consumer Federation of America 

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EPA CO2 Standards 

[These comments were submitted as testimony at the Detroit public hearing. See docket 

number OAR-2009-0472-6185, pp. 106-107.] 

In particular, EPA and NHTSA should balance the three goals in the underlying statutes 

of technical feasibility, economic practicability, and the need to conserve energy, and the 

statutes really are in agreement here, by setting the standard at the mid point of the range 

between maximum economic benefit and maximum practicable environmental benefit. 

EPA Response: 

The Center for Biological Diversity states that the agencies arbitrarily “do not analyze the 

costs and benefits of requiring manufacturers to abandon the [5-year] redesign cycle in 

favor of much quicker and more nimble technology implementation” (comment p. 14). 

They argue further that “strict adherence to this [5-year] cycle is baked into each analysis 

the Agencies present”, and that this analysis is therefore arbitrary. 

The Center’s reference to “much quicker and more nimble technology implementation” 

glosses over many critical considerations. Manufacturers adding substantial amounts of 

new technology to an existing vehicle would need to go through a redesign of that 

vehicle, in the sense that all of the steps undertaken during the standard redesign cycle 

would be needed to be undertaken earlier. For example, manufacturers would have to 

assure that the new technology features are properly calibrated with other vehicle 

systems, that all safety standards are satisfied, that emission standards can be met, etc. 

Vehicle platforms may need to be modified, as well. The upshot is that manufacturers 

cannot bypass a redesign process as the Center assumes. They essentially have to 

redesign in a more rapid timeframe – i.e. to accelerate the redesign cycle process. 

This is not a mere semantic distinction. As just explained, all of the collateral design 

steps that go with redesign would need to be undertaken. The next paragraph notes the 

resource implications involved in doing so. Manufacturers could avoid the most drastic 

of these implications by adding less technology, but this would defeat the purpose of the 

rule to force more widespread penetration of the more significant GHG control 

technologies and not to forego ultimate feasible and cost-effective emission reductions in 

favor of quicker implementation of less technology. (EPA already assumes that the most 

easily applied technology can be applied in the 2012 MY to all vehicles.) 

If full scale redesigns are attempted earlier, then manufacturers would have to ramp up 

resources drastically in order to do so. As a simple example, if a redesign cycle is 

shortened from five years to four, 25% more engineers would be required. Furthermore, 

redesigns require a significant outlay of capital from the manufacturer. This includes 

research and development, material and equipment purchasing, overhead, benefits, etc. 

These costs are significant and are included in the cost estimates for the technologies in 

this rule. Because of the manpower and financial capital constraints, it would only be 

possible to redesign all the vehicles across a manufacturer’s line simultaneously if the 

manufacturer has access to tremendous amounts of ready capital and an unrealistically 

large engineering staff. However no major automotive firm in the world has the 

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EPA Response to Comments 

capability to undertake such an effort, and it is unlikely that the supplier basis could 

support such an effort if it was required by all major automotive firms. The commenter 

provides no information to challenge this conclusion.3

 Even if this unlikely condition 

were possible, the large engineering staff would then have to be downsized once the 

entire fleet had been redesigned at this faster pace. The overall effect would be to 

significantly increase the cost of the vehicles. 

Moreover, there is much evidence to indicate that the average redesign cycle in the 

industry is about 5 years.4

 There are some manufacturers who have longer cycles, and 

there are others who have shorter cycles for some of their products. EPA believes that 

there are no full line manufacturers who can maintain significant redesigns of vehicles 

(with relative large sales) in 1 or 2 years, and CBD has provided no evidence indicating 

this is technically feasible. 

Accordingly, the agencies have not provided quantified estimates of the costs of massive, 

industry-wide acceleration of the redesign process but note that such an undertaking 

raises the most basic issues of feasibility coupled with enormous increase in costs. 

The Center also comments that because the standards are based on performance of 

technology already in existence, this indicates that much more stringent standards should 

be adopted, and even that the MY 2016 standards are immediately feasible. The Center 

also points to fuel economy standards of other industrialized nations as support for its 

proposition that much more stringent standards should be adopted. 

As explained in section III.D. 7 of the preamble to the final rule, existence of technology 

cannot be equated with its fleet-wide application. Significant issues of lead time exist to 

allow the large-scale penetration of technology throughout the fleet to meet the final 

standards, much less more stringent alternatives. Among the critical issues (largely 

ignored by the commenter) are the availability of sufficient capital and technical 

personnel. In addition, it takes several years to redesign a vehicle, and several more to 

design an entirely new vehicle not based on an existing platform. Thus, redesign cycles 

are an inextricable component of adequate lead time under the Act. Other lead time and 

cost issues are raised as well, such as the issue of stranded capital both for the original 

equipment manufacturer (OEM), but up and down the OEM supply chain. 

Nor is the comparison with other nations’ fuel economy standards proper, given (among 

other things) the different fleet mixes involved and the different test procedures utilized. 

In fact, as explained in the preamble discussion, these nations’ standards are predicated 

 

3

 The commenter states that the redesign cycle has vanished altogether in some instances, citing to 74 FR at 

49488. This passage, however, describes vehicle models for which production has ceased altogether or has 

been drastically curtailed. The commenter also states, correctly, that some vehicle models are redesigned 

and refreshed more frequently in some years than in others (citing to 74 FR at 49654), but this only 

indicates that the typical 5-year redesign cycle occurs at different times for different vehicles. The fact that 

redesign cycles are staggered throws no light on the issue raised by the commenter of the feasibility and 

costs of drastically accelerating the redesign process industry-wide. 4

 See for example “Car Wars 2010-2013, The U.S. automotive product pipeline”, John Murphy, Research 

Analyst, Bank of America/Merrill Lynch research paper, July 15, 2009. 

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EPA CO2 Standards 

on use of the same technologies projected for the final GHG standards. Moreover, if one 

is to compare these standards with those of another entity, the most directly relevant 

comparison is with the GHG standards for light duty vehicles of the State of California. 

The federal standards are of comparable stringency.

A comparison of the 2011 MY fuel economy and CO2 emission levels projected in 

NHTSA's 2011 MY CAFE rule (including the proposed rule which contained projections 

through 2016) and those projected is only minimally relevant to the projection of feasible 

and cost effective standards in MY 2016. First, the sales of specific vehicle models and 

vehicle segments differ significantly between the two rulemaking analyses. The 

projections for the NHTSA 2011 CAFE rule were based in large part on manufacturer 

product plans which are now several years old. Those for the current rule are based on 

projections made by an industry analyst, CSM International. Differences in projected 

fleetwide fuel economy and CO2 emission levels would be primarily a function of 

relative car and trucks sales and relative size of these vehicles. Both of these factors 

change between MYs 2011 and 2016 in both sets of projections. Thus, few legitimate 

inferences can be drawn from the difference between the MY 2011 rule projections about 

MY 2016 and the analysis for this final rule. 

The specific cost and effectiveness of a number of technologies has also changed 

between the two rule making analyses. Future fuel prices also differ, as do a number of 

other important factors, such as annual VMT per vehicle, the rebound rate, etc. Thus, 

again, the comparison being made by NYDOT between the CAFE 2011 MY fuel 

economy levels in previous rules to that made in the NPRM is not reliable, and the 

comparison is particularly misplaced regarding those projections based on economic 

criteria, such as standards projected to maximize net quantifiable benefits. 

NYDOT also recommends that EPA implement CO2 standards equivalent to the fuel 

economy standards resulting from NHTSA’s 'Total Costs Equal Total Benefits (TCTB)' 

alternative for passenger vehicles and the 'Technology Exhaustion' alternative for light 

duty trucks. These two scenarios require the application of even more technology and 

involve even higher costs than that of the 6% reduction per year scenario. Thus, the same 

concerns presented above for the 6% reduction per year standards apply to an even 

greater extent here. This is sufficient reason to reject NYDOT’s recommendation. 

3.3.2 2012-2015 Standards 75 

Organization:Mercedes-Benz (Daimler AG) 

Chrysler Group LLC (Chrysler) 

Mitsubishi Motors R & D of America (MRDA) 

Volkswagen Group of America (Volkswagen) 

Toyota Motor North America 

Recreational Vehicle Industry Association (RVIA) 

Mercedes-Benz (Daimler AG) 

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EPA Response to Comments 

The passenger car standards should be set to reach the MY 2016 goals through a 

generally linear stringency level phase-in through MYs 2012-2015. Using a generally 

linear phase-in is both consistent with the agencies’ Notice of Intent and with the 

overarching policy of transitioning to a U.S. vehicle fleet. [OAR-2009-0472-7193.2, p.1] 

[The following comments are nearly the entirety of the statement for the above 

subheading, from [OAR-2009-0472-7193.2, p.2-4] 

In the Notice of Intent published on May 22, 2009 and announcing EPA and NHTSA’s 

intention to publish joint rulemaking, the agencies made clear their intentions to propose 

GHG standards capable of achieving on average 250 g/mile of CO2 in model year 2016, 

and further that “[t]he standards for earlier years would begin with the 2012 model year, 

with a generally linear phase-in from MY 2012 through to model year 2016. NHTSA 

expects to propose appropriate related CAFE standards.” 74 Fed. Reg. 24007, 24008 

(May 22, 2009) (emphasis added). 

Rather than following the foregoing guideline, the proposed standards place a substantial 

amount of emphasis on passenger car improvement in the earlier model years. This 

creates additional challenges, not anticipated at the time of the Notice of Intent, for 

manufacturers whose fleets are primarily composed of passenger cars, and in particular 

for limited-line, lower-volume manufacturers who were to be provided lead time through 

the TLAAS. 

These additional challenges not only make the flexibilities and credits proposed in the 

GHG program more significant, they also mandate careful consideration by the agencies 

of additional flexibilities, such as including air conditioning credits in the CAFE 

program. Further, placing an earlier and larger burden on the light-duty vehicle 

population, as opposed to equalizing the annual increases, raises serious questions as to 

whether the regulatory policy of this proposal is encouraging the appropriate type of fleet 

mix to redress the serious public health and welfare and energy security concerns leading 

to this rulemaking. 

As noted above, the Notice of Intent expressed an intention to design a program that 

would equal the levels in the California program at the end of the rulemaking period, or 

by MY 2016. The Notice of Intent clearly indicates not that California levels were to be 

achieved each year, but rather that they would be reached by MY 2016 and that the 

interim years would be generally linear. DAG submitted a letter to Secretary LaHood and 

Administrator Jackson making clear its commitments based on EPA proposing national 

GHG standards and NHTSA proposing CAFE standards for MYs 2012-2016 “as 

substantially described in the May, 2009 Notice of Intent to conduct rulemaking” and 

certain additional actions. See DAG Commitment Letter, available at 

http://www.epa.gov/otaq/climate/regulations.htm#1a. While DAG nonetheless remains 

committed to meeting the standards, DAG considers the movement away from generally 

linear stringency changes to those focusing on MYs 2012 and 2013 to be a substantial 

deviation from the description provided in the May 2009 Notice of Intent. 

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EPA CO2 Standards 

Chrysler Group LLC (Chrysler) 

The endpoint 2016 model year EPA greenhouse gas industry fleet average standard of 

250 g/mile was as expected, based on the Notice of Intent. The Notice of Intent states that 

'the standards for earlier years (pre-2016) would begin with the 2012 model year, with a 

generally linear phase-in from MY 2012 through to model year 2016' (emphasis added). 

However, the Proposed Rules shows that the intermediate 2012-15 MY standards 

increase in a significantly non-linear fashion at the start of the program - front loading a 

disproportionate amount of the task to the early years of the program. In particular, the 

passenger car standard increase between the 2011 and 2012 model years is more 

aggressive than necessary. [NHTSA-2009-0059-0124, p.8] [[Chrysler also submitted 

these comments as testimony at the Detroit public hearing, See docket number EPA-HQOAR-2009-0472-6185, p. 49.] 

Moreover, President Obama's Rose Garden Remarks also noted that 'the goal is to set one 

national standard that will rapidly increase fuel efficiency ... by an average of five percent 

each year between 2012 and 2016, building on the 2011 standard ..., (emphasis added). 

Although 2012 is the first year of the EPA program, given the 'direct and close, 

relationship between tailpipe greenhouse gas emissions and fuel economy, the 2011 

NHTSA CAFE standards (and their equivalent in greenhouse gas emissions terms) 

should have been used when determining the phase-in to the 2016 model year goal. 

[NHTSA-2009-0059-0124, p.8] 

In the NPRM, excluding model years 2009-2011, EPA and NHTSA propose a generally 

linear phase-in between the 2012 and 2016 model years, but the passenger car greenhouse 

gas emission reduction of 11.2% between the 2011-2012 model years is extremely steep 

and unprecedented. The industry average truck fleet also has the largest GHG emission 

reduction of 4.6% between the 2011-2012 model years. [NHTSA-2009-0059-0124, p.8] 

In addition to the numerically large increase in passenger car standards between the 2011 

and 2012 model years, manufacturers need to simultaneously accommodate changes to 

the passenger car fleet definition. Beginning in the 2011 model year, certain 2WD lightduty trucks are reclassified as passenger cars. In the 2012 model year, additional lightduty trucks are re-classified as passenger cars based on a lack of 3-row standard seating. 

These reclassifications move truck-like utility vehicles from the light-duty truck category 

to the passenger car category, subjecting them to more stringent standards and, as a 

result, they become relatively poorer fuel economy and greenhouse gas performers, 

reducing manufacturers' ability to comply with the more stringent passenger car 

standards. [NHTSA-2009-0059-0124, p.9] 

While the ability to earn credits and the carry-forward and carry-back credit flexibility 

helps manufacturers' ability to comply, the large jump in standards is at a time when 

manufacturers can do little to impact the actual fleet performance. Given typical model 

year lead times, this setting of extremely aggressive 2012 model year standards does not 

allow for sufficient leadtime to re-engineer vehicles to meet this stringency increase. The 

type of major product changes necessary to increase vehicle efficiency by over 10% 

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EPA Response to Comments 

requires sufficient time to re-engineer vehicles. This type of change normally occurs 

during a product re-design or a new product release, not mid-model year modifications. 

[NHTSA-2009-0059-0124, p.9] 

Recommendation: 

Chrysler recommends that the agencies set passenger car and light-duty truck standards 

with a linear phase-in to the 2016 model year goals as envisioned during the signing of 

the May 2009 manufacturer and California Letters of Intent in response to the National 

Program. Chrysler supports the general methodology of linearizing the standards 

suggested by the Alliance of Automobile Manufacturers. [NHTSA-2009-0059-0124, p.9] 

Mitsubishi Motors R & D of America (MRDA) 

There are significant challenges in the increased stringency between the 2011 and 2012 

model years. The rate of this increase will likely result in excessive costs and burdens as 

many vehicles are quickly reconfigured to comply with these new standards. [OAR-2009-

0472-7125.1, p.1] 

Smaller Automakers need more time to develop new technologies and to implement 

design changes. The proportional effort is much greater to meet stringent standards and 

far less resources are available for long term R&D to develop and introduce new 

technologies. Further, smaller Automakers are unable to negotiate timely, cost effective 

supplier contracts – suppliers favor high volume Automakers and limit the technology 

available to smaller Automakers. Overall, it takes longer/costs more for limited line 

vehicle manufacturers to introduce new technologies. [OAR-2009-0472-7125.1, p.2] 

The proposed stringent standards are particularly challenging for limited line, 

“intermediate volume” manufacturers, especially considering that Mitsubishi Motors was 

not subject to the California AB1493 GHG regulations until the MY 2016. [OAR-2009-

0472-7125.1, p.5] 

Volkswagen Group of America (Volkswagen) 

In addition, Volkswagen questions the need for the large step in stringency proposed 

from the 2011 MY CAFE regulation to the 2012 MY targets proposed in the NPRM. We 

believe the 2016 MY target combined fleet target of 250 gram/mile is achievable and that 

the targets for each model year can be adjusted to meet the same air quality targets 

without such a large jump in the requirements in the first year of the regulation. [OAR2009-0472-7210.1, p.5] 

Toyota Motor North America 

Ramp Rate of the Target Curves 

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EPA CO2 Standards 

The rate of increase in the proposed car targets by both agencies is front-loaded and 

should be adjusted. As can be seen in Figures 1 and 2, the rate of increase in the car target 

curves between 2011 MY and 2012MY is inconsistent with the rates of increase in 

subsequent model years. The largest increase in target values occurs in the first year of 

the proposed regulation, when manufacturers have the least available lead time to 

integrate technology into the fleet. While the curves are shown only for NHTSA's portion 

of the joint proposal (in MPG space), EPA's proposed target curves show the same trend. 

[OAR-2009-0472-7291,p.9] 

Consistent with comments provided by Toyota in previous CAFE rulemakings, we 

suggest the rate of increase be 'smoothed' between the existing 2011 model year car 

curves and the final 2016 model year proposed curves. Such an adjustment would align 

more closely with product planning cycles and lead time requirements. [OAR-2009-

0472-7291,p.9] [See OAR-2009-0472-7291, pp.9-11 for a detailed discussion on this 

issue] 

Recreational Vehicle Industry Association (RVIA) 

RVIA believes that with the non-linear standards increase proposed, to achieve 

compliance, some manufacturers may opt to eliminate certain non-compliant vehicles 

from their product mix since compliance otherwise may not be technologically feasible. 

We are concerned that tow vehicles could be likely candidates for such eliminations since 

the cost of technology to achieve such abrupt improvements may diminish their 

commercial viability. To ensure that highway safety and air quality are not negatively 

impacted by RV owners who tow their RV trailers with undersized vehicles or keep 

older, less environmentally friendly tow vehicles on the road, we ask that you implement 

a more gradual rollout of the standards. [NHTSA-2009-0059-0107, p.5] 

One of the key points found in the General Motors comments dated November 20, 2009, 

is that the '... the car standard detailed in the NPRM does not even 'encourage' limited 

product line manufacturers to increase vehicle fuel economy.' GM goes on to state, 

'Because the NPRM curves require little improvement from cars and small trucks, there is 

a lost opportunity for fuels savings for the nation. As an example. increasing the 

stringency of the NPRM curves by 10% for the smallest vehicles and reducing the 

stringency by 5% for the largest trucks, would result in more energy savings, and enable 

more economically practical application of technology across the country.' [NHTSA2009-0059-0107, pp.5-6] 

Given that small cars are essentially already meeting the 2016 model year standards, such 

a trade off makes sense. RVIA would support such a measure and encourages a careful 

re-examination of the assigned mpg/C02 targets for both small vehicles and larger trucks. 

[NHTSA-2009-0059-0107, p.6] 

EPA Response:

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EPA Response to Comments 

EPA believes that the standards for MY 2012-2016 are consistent with the Notice of 

Intent which stated that “The standards for earlier years would begin with the 2012 

model year, with a generally linear phase-in from MY 2012 through to model year 2016.” 

Those standards likewise represent a reasonable exercise of EPA's authority under section 

202 (a)(1) of the Act. See, e.g. section III.D of the preamble to the final rule; see also 

comment response 3.3.3.3.1. EPA acknowledges that the standards for passenger cars 

have a higher rate of increase from MY 2011 CAFE standards to MY 2012 GHG 

standards; however there are several reasons that this is a misleading comparison. First, 

the form of the 2011 standard (the footprint based curve) differs considerably from the 

form of the MY2012-2016 standards. The baseline and reference fleets and many of the 

underlying technical assumptions used to approximate the fleet targets and stringencies 

for the 2011 rulemaking also differ from the ones used for this rule. The automotive 

industry commenters above do not point to a specific technical issue with the standards, 

but rather to their desire for a linear phase-in from the existing 2011 CAFE standards. 

These arguments are addressed in NHTSA’s response to comments in section IV of the 

preamble to the final rule and in the NHTSA RIA. As to meeting the 2012 MY GHG 

standards, EPA notes further that the various flexibility mechanisms in the rule (e.g. 

TLAAS, early generation of credits for out-performing California standards, averaging, 

banking and trading with carry backward of credits if needed) ) provide ready means for 

manufacturers to comply with the MY 2012 GHG standard. For example, since issuance 

of the NPRM, it has come to light that some manufacturers may be implementing more 

air conditioner leakage reduction technologies than EPA had anticipated (see section 

III.C.1.a of the final preamble; see also comment response 3.1). This would result in 

additional early credits that could be carried forward to help meet MY 2012 standards. 

Because of these arguments, and due to the support for the phase-in of the standards from 

other stakeholders (including the California Air Resources Board) the agency is not 

making significant changes to the MY 2012-2016 GHG standards. For further discussion 

on the feasibility of the EPA standards, see section III.D of the final preamble. 

3.3.3 Post 2016 standards 

Organization: Sierra Club 

 Ford Motor Company 

Northeast States for Coordinated Air Use Management 

BMW of North America, LLC (BMW) 

New York State Department of Environmental Conservation 

State of Connecticut Department of Environmental Protection 

Union of Concerned Scientists 

 

Comment: 

The industry, however, needs a longer term and stronger direction to be able to produce 

dramatically cleaner vehicles. We urge EPA to move swiftly to set standards that will 

apply to vehicles beyond 2017 and to consider a longer time horizon to ensure that lead 

time is not a constraint on the “technology forcing” authority EPA can exercise under the 

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EPA CO2 Standards 

Clean Air Act. As soon as the endangerment finding is final, EPA will have the 

obligation to set standards for greenhouse gas pollutants that protect public health and 

welfare. To do this effectively, EPA should model where vehicle standards need to be in 

2050 to achieve an 80% reduction (or the appropriate science-based emissions reductions 

needed) in vehicle emissions. Starting in 2017, EPA should give a clear “technology 

forcing” path to the auto industry. [OAR-2009-0472-7278.1, p.13] 

A longer term approach is consistent with EPA’s authority and statutory obligation under 

the Clean Air Act and with the analysis of the industry’s ability to achieve higher 

standards in this NPRM. In this NPRM EPA considers three options. EPA identifies the 

annual 4.3% decrease in g/mi CO2e as the preferred option – the option that yields the 

250 g/mi CO2 standard President Obama announced in May 2009. The agency considers 

a lower 4% and higher 6% option. EPA notes that that the 4% option 'forgoes CO2 

reductions which can be achieved at reasonable cost.” EPA also notes that this lower 

option would be too weak to achieve equivalence with California’s Pavley [OAR-2009-

0472-7278.1, p.13] standards and would, therefore violate the agreement. The 6% 

increase would increase the cost of a new vehicle by an average $500 with additional 

greenhouse gas reductions. EPA determines that this level is not “technically infeasible” 

but that it would be “overly stringent” given the condition of the industry and lack of lead 

time. EPA concludes that the preferred option demands enough of the industry in terms 

of technology change and cost. [OAR-2009-0472-7278.1, p.14] 

EPA seeks comment on its judgment regarding the three options. In sum, EPA concludes 

that it “does not believe the 6% per year alternative would be an appropriate balance of 

various relevant factors for model years 2012–1016.” We applaud EPA for ensuring that 

equivalence with California’s standards are met in this first National Program, but urge 

the agency to ensure that its next standards do not leave greenhouse gas reductions and 

consumer savings unrealized. To do this EPA must look at the longer term and push the 

industry’s best technologies into new cars and light trucks that both force technology 

forward and maximize their greenhouse gas potential. [OAR-2009-0472-7278.1, p.14] 

NHTSA provides a slightly different approach to a range of from a 3% per year increase 

in fuel economy to 7% - but notes that the 4.3% preferred option achieves the 250 g/mi 

CO2 needed for equivalence with CA’s program and yields a fleetwide average fuel 

economy of 34.1 mpg (equivalent to 250 g/CO2e). NHTSA, based on its statutory 

obligation to consider the need of the nation to conserve oil, concludes that weaker 

increases – 3 or 4% would “not produce the reductions in fuel savings and CO2 

emissions that the Nation needs at this time.” NHTSA’s conclusion that weaker standards 

leave substantial benefits on the table is not matched by the rationale for picking the 

preferred option over the somewhat stronger choices. “NHTSA determined that it would 

be inappropriate to propose any of the other more stringent alternatives due” to lead time 

issues and “economically critical state of the industry.” NHTSA diverges from past 

proposals which considered setting the standards at a level that maximizes societal net 

benefits. [OAR-2009-0472-7278.1, p.14] 

Ford Motor Company 

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EPA Response to Comments 

Above all, Ford strongly believes that measures need to be put in place to ensure that the 

national program approach outlined in this rulemaking continues beyond 2016. We were 

pleased when the President brought the stakeholders together to agree on a roadmap for 

harmonizing greenhouse gas emissions and CAFE standards at the federal level. The 

EPA and NHTSA proposal gives us greater clarity, certainty and flexibility to achieve the 

aggressive greenhouse gas emissions reduction goals that we all share. Most importantly, 

it avoids the patchwork and overlapping requirements that we would have faced under 

the status quo. Nonetheless, it is only a first step, and it is critical that we avoid returning 

to the patchwork approach after 2016. We look forward to working with the same 

stakeholders toward a permanent national program for 2017 and beyond. [OAR-2009-

0472-7082.1, Cover letter, p.2] 

. Although the national program created by this rule covers the 2012-2016 model years, it 

is critical that measures be put in place to establish a permanent national program for the 

2017 model year and beyond. [OAR-2009-0472-7082.1, p.1] 

Northeast States for Coordinated Air Use Management 

NESCAUM is very supportive of the proposed federal vehicle control program as a 

powerful first step in addressing GHG emissions from motor vehicles. However, 

additional reductions will be needed for vehicles beyond model year 2016. NESCAUM is 

committed to working with the EPA, NHTSA, the California Air Resources Board, and 

other stakeholders to address global climate change and the need to reduce oil 

consumption by developing strong motor vehicle GHG standards for model years after 

2016. These additional reductions will be critical for the states in the Northeast to achieve 

their 2020 and 2050 GHG goals. [OAR-2009-0472-7235.1, p.7] 

BMW of North America, LLC (BMW) 

To ensure future regulatory stability for the auto industry while continuing to reduce 

greenhouse gas emissions and improve fuel fleet economy, BMW strongly recommends a 

comparable National Program in the model years beyond 2016. We are very, very happy 

with the way the negotiations, discussions, collaboration and cooperation have gone to 

come up with this single national standard and we very, very strongly support the same 

process for the years 2016 and beyond. [These comments were submitted as testimony at 

the New York public hearing. See docket number EPA-HQ-OAR-2009-0472-4621, p. 

132.] 

New York State Department of Environmental Conservation 

We do not believe that the 2016 model year standards proposed here represent the 

ultimate, lowest limit for light duty vehicle greenhouse gas emissions. We believe that 

lower emissions will be possible in the future without sacrificing the utility these vehicles 

provide their owners. We urge EPA and NHTSA to continue to evaluate the feasibility of 

more stringent regulations. We do hope the nation will not have to wait another 30 years 

for the next step. [OAR-2009-0472-7454, cover page 2] 

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EPA CO2 Standards 

State of Connecticut Department of Environmental Protection 

Any standards developed for 2016 and later should comprehensively evaluate the need 

for and benefits of a multi-pollutant perspective, including criteria and air toxics along 

with GHGs, that views vehicles and fuels as a system. Assuming additional standards are 

warranted, the next phase of light duty vehicle standards should view the transportation 

system in a holistic manner that takes into account vehicles, fuels and the transportation 

infrastructure that can be designed to enable greater levels of pollution or to minimize it. 

[OAR-2009-0472-7301, p.2] 

Union of Concerned Scientists 

Finally, I wanted to discuss the importance of establishing a strong regulatory framework 

for future rulemakings as part of this process. While the immediate focus of this 

rulemaking is achieving the President's goals through model year 2016, it will also set the 

precedent for future standards beyond that date. [These comments were submitted as 

testimony at the New York public hearing. See docket number EPA-HQ-OAR-2009-

0472-4621, p. 101.] 

It is critical that future standards achieve the maximum feasible [These comments were 

submitted as testimony at the New York public hearing. See docket number EPA-HQOAR-2009-0472-4621, p. 101.] level of energy savings as required by EPAct and EISA 

as well as fulfill EPA's obligations under the Clean Air Act. Under this rulemaking, EPA 

and DOT have set standards that fall below the economically practicable levels indicated 

by the agencies' own analysis. This means that Americans will not realize the full benefits 

of the Nation Program through 2016. UCS recognizes that the current standards were set 

at a more modest level to help automakers achieve the standards given the financial 

problems facing the industry and the challenges of navigating a new regulatory structure. 

However, it's critical that future standards are set at levels that achieve the maximum 

benefits of the National Program. These standards should be based on sound modeling 

that uses accurate technology assessments, verified costs and transparent input. [These 

comments were submitted as testimony at the New York public hearing. See docket 

number EPA-HQ-OAR-2009-0472-4621, p. 102.]

EPA Response:

EPA appreciates all of the comments expressing concern that 2017 and later GHG 

standards be set sufficiently soon so that the lack of available lead time does not limit the 

stringency of the standards. EPA is also sensitive to how complex and undertaking this 

will be and that a new National Program will provide a level of certainty for the 

manufacturers so that they may modify their long term product planning. We will 

consider these issues seriously as we proceed to evaluate post 2016 GHG standards for 

light-duty vehicles. 

3.3.4 GHG Emissions Backstops 

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EPA Response to Comments 

In the proposal, EPA and NHTSA recognized “that there is some possibility that low fuel 

prices during the years in which MY 2012-2016 vehicles are in service might lead to less 

than currently anticipated fuel savings and emissions reductions. One way to assure that 

emission reductions are achieved in fact is through the use of explicit backstops, fleet 

average standards established at an absolute level.” EPA stated that a backstop “could be 

adopted under section 202(a) of the CAA assuming it could be justified under the 

relevant statutory criteria.” EPA did not propose backstop standards, but sought 

comment on possible backstop approaches. 

EPA and NHTSA received many comments on backstops. In this section, EPA responds 

to both specific comments on GHG emissions backstops, as well as to general comments 

on backstops that were submitted to both EPA and NHTSA. In the latter case, where 

comments were made jointly on both EPA GHG emissions backstops and NHTSA CAFE 

backstops, EPA’s response only addresses the issue of GHG emissions backstops. 

EPA received 26 public comments on the issue of GHG emissions backstops. There is 

significant overlap among the comments on this issue, and the structure of this section is 

to provide a comprehensive sampling of excerpts of these 26 comments, followed by an 

EPA response to the comments organized into 3 sections: 

• Whether EPA has the statutory authority to establish GHG emissions backstops 

• Whether EPA should establish GHG emissions backstops 

• Alternative backstop approaches to universal GHG emissions backstops 

Organization: Alliance of Automobile Manufacturers (Alliance) 

American Council for an Energy Efficient Economy 

American Lung Association of California 

Association of International Automobile Manufacturers (AIAM) 

California Air Resources Board 

California State Senate 

Center for Biological Diversity 

Connecticut Department of Environmental Protection 

Environment Michigan 

Environment New Jersey 

Ford Motor Company 

Mass Comment Campaign (2,322 comments) (unknown organization) 

Mass Comment Campaign (326 comments) (Student PIRGs) 

Massachusetts Department of Environmental Protection 

National Automobile Dealers Association (NADA) 

Natural Resources Defense Council 

Northeast States for Coordinated Air Use Management (NESCAUM) 

Public Citizen Safe Climate Campaign 

Seal, Kathy 

Sierra Club 

State of New Jersey 

Toyota Motor North America 

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EPA CO2 Standards 

Union of Concerned Scientists 

United Auto Workers 

University of Pennsylvania Environmental Law Project 

Washington Department of Ecology 

Comment: 

Ford Motor Company

Backstops 

Backstops should not be combined with attribute-based standards unless specifically 

required by statute. Backstops are inefficient and force manufacturers to produce vehicles 

that consumers may not want. Moreover, they are unnecessary. The sloped portion of the 

piecewise linear curves takes into account size based product mix differences across the 

industry and adjusts automatically for changes in vehicle size mix in response to 

economic conditions and consumer preferences. The flattened portion of the car and truck 

curves serves a function akin to a backstop by discouraging manufacturers from building 

larger vehicles. Moreover, NHTSA has commented in past rulemakings that the curve of 

an attribute-based standard has several features that limit backsliding. 74 FR at 14410. 

[OAR-2009-0472-7082.1, pp. 2-3] 

GHG Backstops 

EPA also seeks comment on the concept of 'backstop' standards for GHG emissions. In 

the NPRM, EPA proposes to establish motor vehicle GHG standards in the form of the 

'C02 curves.' The authority and justification for the establishment of any additional 

'backstop' standards underlying the CO2 curves is highly questionable. First, the Clean 

Air Act (CAA) § 202(a) does not mention the concept of 'backstop' standards, let alone 

authorize EPA to promulgate them. The concept of 'backstop' standards would involve 

promulgating two sets of standards (the main standards and the backstop standards) 

applicable to a given fleet of vehicles, and there is nothing in the CAA to suggest that 

Congress intended multiple 'layers' of standards to apply to vehicle emissions. 

Second, EPA is presumably already taking the statutory criteria in § 202(a) into account 

in its development of proposed CO2 curves. Backstop standards would need to meet the 

same criteria, and the agency would need to conduct a separate evaluation of both the 

backstop standards on their own, and the combination of the backstop and main 

standards, under those criteria. However, it is far from clear that the § 202 criteria would 

support a second set of standards for the same vehicles. Backstop standards would likely 

impact individual manufacturers very differently. The most likely effect of backstop 

standards would be to prevent full-line manufacturers from building and selling vehicles 

that the market wants and that could otherwise be sold under the primary standards. This 

could have a significant financial impact on a few individual manufacturers most affected 

by the backstop standards, while having a negligible impact on overall projected 

concentrations of GHGs. A key purpose of the attribute based approach is to reduce the 

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EPA Response to Comments 

impact of vehicle mix and put manufacturers on a more level playing field; the addition 

of backstop standards would run counter to this goal. At present, the Administrator has no 

basis for concluding that backstop GHG standards are necessary to protect health and 

welfare. Given the potential costs and disparate competitive impacts that backstop 

standards may impose on individual manufacturers, EPA should not pursue such 

standards. 

Finally, as noted above, the intent of the joint EPA/NHTSA proposal is to ensure the 

greatest possible level of consistency between fuel economy standards issued by NHTSA 

and CO2 emission standards established by EPA. Even if EPA had the authority under 

the CAA to independently establish backstop standards, any EPA-issued CO2 emission 

standards would only serve to create new inconsistencies between the two programs, 

rather than further the goal of harmonization. Ford supports the harmonization of the 

EPA and NHTSA standards to the maximum extent possible, consistent with the 

Massachusetts v. EPA decision directing the federal agencies 'avoid inconsistency' in 

regulating greenhouse gas and fuel economy. The best way to 'avoid inconsistency' in this 

case is to allow NHTSA to establish the one backstop required by law for CAFE, and 

avoid any other backstops in the CAFE or GHG regulations. [OAR-2009-0472-7082.1, 

pp. 3-4] 

Association of International Automobile Manufacturers (AIAM) 

AIAM opposes the adoption of an additional “backstop” (i.e., minimum conventional) 

standard as a means of preventing market shifts toward larger vehicles. A backstop 

standard would defeat the purpose of the attribute format by limiting the flexibility of 

manufacturers to respond to shifts in market demand. Moreover, when Congress 

considered the need for a backstop standard in the similar context of CAFE standards 

under EISA, it adopted a limited “minimum standard” for domestic passenger 

automobiles. The EISA backstop provisions require that a manufacturer’s domestic 

passenger auto fleet must comply with the greater of 27.5 mpg and 92 percent of the 

combined domestic/import average fuel economy of all manufacturers. See EISA, section 

102(b)(4). An additional backstop standard in an EPA greenhouse gas regulatory program 

would be inconsistent with Congress’ intent and would be unnecessary and inappropriate. 

[OAR-2009-0472-7123.1, p.18] 

In Center for Biological Diversity v. NHTSA, the Ninth Circuit held that “neither the 

EPCA’s language nor structure explicitly requires NHTSA to adopt a backstop.” Rather, 

the court held that NHTSA had abused its discretion in failing to adequately consider the 

“need of the nation to conserve energy,” as it was required to do under 49 USC § 

32902(f), and did not show that a backstop would be technologically infeasible or 

economically impracticable. EISA did not expressly change this. The only backstops 

required are the requirements in EISA that the combined car-truck fuel economy values 

reach 35 mpg by MY2020 and that the regulations established between MY2011 and 

MY2020 increase ratably to that goal. So long as NHTSA makes the showing that the 

standards meet these requirements, then nothing more should be required in terms of a 

backstop. [OAR-2009-0472-7123.1, p.18] 

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EPA CO2 Standards 

[AIAM also submitted these comments as testimony at the Los Angeles public hearing. 

See docket LA EPA Hearing EPA-HQ-OAR-2009-0472-7283, pp. 28-32] 

Alliance of Automobile Manufacturers (Alliance) 

EPA's Backstop Authority 

As noted above, the intent of the joint EPA/NHTSA proposal is to ensure the greatest 

possible level of consistency between fuel economy standards issued by NHTSA and 

CO2 emission standards established by EPA. Even assuming EPA has the authority under 

the CAA to independently establish backstop standards, which is unclear, any EPAissued backstopped CO2 emission standards would only serve to create inconsistencies 

between the two programs, which would be contrary to the directive of the Supreme 

Court in Massachusetts v. EPA that federal agencies “avoid inconsistency” in regulating 

GHGs and fuel economy. See Massachusetts v. EPA, 549 U.S. 497, 532 (2007). 

Because of differences between EPCA and the CAA, NHTSA's proposed CAFE rules 

include domestic and import passenger car fleets, while EPA's proposed GHG rules do 

not include the domestic/import distinction for passenger cars. Under EISA, as explained 

above, only the domestic passenger car fleet is subject to a backstop under the NHTSA 

CAFE rules. EPA cannot duplicate this under its rules; any "backstop" standards EPA 

might seek to promulgate would presumably apply to all passenger cars. Were EPA to 

proceed with such backstop standards, it would impose a new set of regulatory 

requirements on a group of vehicles (imported passenger cars) that are not affected by the 

backstop under NHTSA's rules. Such an outcome would only add to the complexity of 

the manufacturers' task of producing a fleet of vehicles that complies with both sets of 

rules. Furthermore, backstops are unnecessary. The concern about widespread vehicle 

upsizing and a loss of anticipated benefits from the proposed standards is greatly 

overstated given practical design considerations and the shape of the proposed attribute 

curves. 

First, upsizing doesn’t necessarily present an easier compliance path. The basic concern 

about upsizing is that manufacturers will be motivated to increase the footprint of their 

fleet since larger vehicles have a less stringent standard under a size-based attribute 

system. This premise ignores that an increase in vehicle footprint typically results in an 

increase in vehicle weight. While upsizing may relax the fuel economy target, 

compliance may be just as difficult due to the loss of fuel economy from the added 

weight. 

Second, increasing vehicle footprint may require vehicle platform changes. The 

opportunity to upsize a vehicle platform is limited by product planning cycles which have 

already been finalized in many cases for basic attributes such as vehicle size. Further, 

changes in vehicle footprint and platform present practical design considerations such as 

vehicle styling and vehicle dynamics/handling. Lastly, these platform changes are not 

without cost. 

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EPA Response to Comments 

Third, any erosion of the anticipated benefits is likely to be minimized by the substantial 

yearly increase in the target curves as well as the shape of the curves for any given year. 

For example, under the proposed standards, the efficiency of a car fleet with an average 

footprint of 45 sq ft is required to improve by 13 percent between 2012 and 2016. To 

completely negate this improvement, the footprint for every vehicle in this example fleet 

would have to be increased by an average of 7 sq ft over that 4-year period. For all of the 

technical reasons mentioned above, such a scenario is highly unlikely, if not impossible. 

Upsizing the footprint by even half this amount, while still not a reasonable scenario, 

would net significant fuel economy improvements. In fact, a backstop is already built 

into the standard curves to the extent the targets become constant or “clipped” as vehicle 

footprint continues to increase. Therefore, the target curves already help guard against 

any loss of benefit from theoretically upsizing into the “clipped” regime. 

From a policy perspective, a backstop introduces an unnecessary secondary standard that 

increases the complexity of the requirements and runs contrary to the intent of an 

attribute-based standard. For these policy reasons and in keeping with the Supreme 

Court's admonishment to "avoid inconsistency," EPA should not seek to adopt backstop 

standards. [OAR-2009-0472-6952, pp 35-36] 

Backstop Standards 

The agencies note that NHTSA is required to set minimum “backstop” standards for 

domestically-manufactured passenger cars and request comment on whether “backstop 

standards, or any other method within the agencies’ statutory authority, should and can be 

implemented in order to guarantee a level of CO2 emissions reductions and fuel savings 

under the attribute-based standards” for other categories of vehicles. Proposed 

Rulemaking To Establish Light-Duty Vehicle Greenhouse Gas Emission Standards and 

Corporate Average Fuel Economy Standards; Proposed Rule, 74 at 49,493. [OAR-2009-

0472-6952.1, p.37] 

The agencies have not established that they have authority to set back-stop standards that 

are not specifically authorized by Congress, and the Alliance is aware of no evidence 

indicating that such back-stops are necessary to achieve the goals and purposes of the 

national fuel economy and emissions programs. Such back-stops would unduly limit 

consumer choice and the industry’s ability to achieve the goals of the new national 

programs as cost-effectively as possible. [OAR-2009-0472-6952.1, p.37] 

Toyota Motor North America 

Anti-Backsliding Standards 

Anti-backsliding or backstop standards currently apply only to the domestic passenger 

fleet under NHTSA's CAFE program. The Agencies request comment on whether antibacksliding provisions should be expanded to all vehicle fleets covered by the proposed 

NHTSA and EPA standards. NHTSA additionally proposes to revise the domestic car 

anti-backsliding standards that were set in the March 2009 final CAFE rule for 2011 MY. 

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EPA CO2 Standards 

Finally, NHTSA proposes to use projected target fuel economy when establishing the 

minimum CAFE standard for the domestic passenger fleet. [OAR-2009-0472-7291, 

pp.14-15] 

Expanding Anti-Backsliding Standards to All Cars and Trucks 

Toyota opposes any expansion of anti-backsliding provisions beyond the domestic 

passenger car fleet in the CAFE program. The clear intent of Congress has been that 

NHTSA should only establish anti-backsliding standards for the domestic car fleet. As 

such, EPCA requires NHTSA to establish anti-backsliding standards for domestic 

passenger cars and does not authorize NHTSA to establish additional anti-backsliding 

standards for import cars and trucks. [OAR-2009-0472-7291, p.15] 

In the case of EPA and CAA, there is no explicit statutory authority that either compels 

or authorizes EPA to establish anti-backsliding standards for any class of light-duty 

vehicle. While EPA's authority may be ambiguous, it is clear that any EPA-issued antibacksliding standards would create new inconsistencies between the NHTSA and EPA 

programs, rather than support the goal of harmonization. NHTSA anti-backsliding 

standards are limited to domestic passenger cars, and the CAA cannot be used to 

duplicate a similar outcome since EPA's fleet definitions do not distinguish between 

domestic cars and import cars. The most 'harmonized' outcome is for NHTSA to proceed 

with the required domestic car anti-backsliding standard for the CAFE program, and for 

EPA to forego any attempt to set anti-backsliding standards under the CAA. [OAR-2009-

0472-7291, p.15] 

Notwithstanding the legal constraints described above, anti-backsliding standards are 

unnecessary. The concern about widespread vehicle upsizing and a loss of anticipated 

benefits from the proposed standards seems overstated given practical design 

considerations and the shape of the proposed attribute curves. [OAR-2009-0472-7291, 

p.15] [See OAR-2009-0472-7291, pp.15-16 for more discussion on this issue] 

Northeast States for Coordinated Air Use Management (NESCAUM) 

NESCAUM urges EPA and DOT to include a backstop mechanism for the standards. The 

shift in the market away from cars towards light trucks in the 1990s resulted in a decrease 

in the U.S. fleet average fuel economy. More recently, there has been a dramatic shift in 

the market towards 4 and 6 cylinder engines and away from 8 cylinder engines. This has 

been accompanied by a shift away from larger trucks and towards smaller trucks and 

cars. The technical analysis conducted for this proposal by EPA and DOT assumes that 

this trend will continue. Should there be a shift back toward higher CO2 emitting vehicles 

(as was the case in the 1990s) the emissions reductions projected by the agency could be 

greatly overestimated. A backstop which sets a floor for reductions would address this 

potential problem. NESCAUM also urges the agencies to revisit the GHG standards and 

incorporate changes in the light-duty vehicle fleet into baseline assumptions. NESCAUM 

believes this is an important element to include in the final rule. We encourage the 

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EPA Response to Comments 

agencies to revisit and revise the light-duty GHG standards to correct for mistaken future 

projections. [OAR-2009-0472-7235.1, p.6] 

Public Citizen/Safe Climate Campaign 

Reaching the agency’s proposed standard of 250 g CO2/mi is predicated on the fleet mix 

of 67 percent cars and 33 percent light trucks in 2016, versus a fleet mix of 51 percent 

cars and 49 percent light trucks in 2008. Some of this shift in the market will result from 

the reclassification of a large number of vehicles that were previously categorized as light 

trucks to passenger cars, which will take effect in the 2011 model year, consistent with 

the final rule for 2011 fuel economy standards. Many of these affected vehicles are twowheel drive versions of vehicles that are also sold in a four-wheel drive configuration. 

[OAR-2009-0472-7050.1, p.2] 

This creates a problem for automakers in manufacturing and marketing these vehicles. 

Automakers would have to build a two-wheel drive version of a vehicle to fit on the “car 

curve” or meet the footprint-based target for fuel economy set for the passenger car fleet 

versus the light truck fleet. There is significant overlap of footprints which are on both 

curves. If automakers successfully build two-wheel drive versions that get the better fuel 

economy required on the car curve, it calls the two-fleet rule into question. Automakers 

may respond to reclassification by simply ceasing to offer two-wheel drive configurations 

of certain SUVs, which would distort the fleet mix and ultimately result in lowering fuel 

economy and raising greenhouse gas emissions. [OAR-2009-0472-7050.1, p.2] 

For this reason, the new standards should include backstops, or some other adjustment 

mechanisms to ensure that there is a firm level below which individual automakers and 

the economy-wide [OAR-2009-0472-7050.1, p.2] fleet of vehicles could not fall. The 

agencies already build in an expectation value based on analysis of the extent to which it 

is estimated that automakers will apply credits. EPA discusses several backstop options 

in its Advanced Notice of Proposed Rulemaking (ANPRM) on greenhouse gas regulation 

under the CAA. An approach that EPA outlines that could be most effective would have 

the standards automatically reset to account for increases in emissions that are 

inconsistent with agency projections at the time of promulgation: [OAR-2009-0472-

7050.1, p.3] 

For example, at the time of promulgation, EPA could assume a certain average industrywide carbon dioxide g/mi emissions level for 2011–2012. If, in 2013, EPA found that the 

average industry-wide emissions level in 2011–2012 was higher than projected in the 

final rule (and therefore the carbon dioxide emissions reductions were lower than 

projected because of higher than projected average footprint levels), then the backstop 

provisions would be triggered and the footprint curves for future years (say, 2016 and 

later) would be automatically changed to be more stringent and/or flatter in shape. This 

approach would reframe the backstop issue in terms of industry-wide emissions 

performance, rather than in terms of individual automaker emissions performance. [OAR2009-0472-7050.1, p.3] 

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EPA CO2 Standards 

A mechanism similar to this would prevent greenhouse gas emissions from rising because 

of unanticipated shifts in the fleet mix. We urge EPA and NHTSA to adopt backstops for 

greenhouse gas emissions and oil consumption to ensure that the goals of the program are 

met, and to discourage manufacturers from continuing to use the light truck loophole to 

undermine advances in fuel economy and reductions in greenhouse gas emissions. [OAR2009-0472-7050.1, p.3] 

Union of Concerned Scientists 

Given the possibility that a fleet average of 250 g/mi may not be reached – either by 

renewed interest in light trucks or by industry gaming of light truck classifications – it is 

critical that the agencies add a backstop in order to guarantee that the President’s 

emissions reductions and energy savings goals are met. While a backstop could take 

numerous forms, UCS suggests one that includes an automatic re-computation or 

“ratchet” of stringencies for subsequent years, such that the National Program’s 

cumulative emissions reductions and oil savings goals are fully achieved in 2016, even if 

falling short in early years of the program. [OAR-2009-0472-7181.1, p.5] 

[Following comments are from LA Testimony, OAR-2009-0472-7283, pp.103-113 (p.6)] 

First, a backstop is necessary to meet California's standards. By 2016, new cars under the 

California program are expected to emit an average of 250 grams per mile of global 

warming pollution. 

To meet this level of emissions, the NPRM projects that in model year 2016 the fleet will 

consist of approximately two-thirds passenger cars and one-third light trucks. But in 

today's new vehicle fleet, nearly half of the vehicles sold in the U.S. are light trucks. 

While there has been a recent market trend away from light trucks towards cars, it 

is questionable whether market pressure alone will achieve such an overall notable shift 

by 2016. Additionally, automakers might strategically redesign vehicles in some classes 

so they might meet higher emissions limits. 

EPA and NHTSA should include a backstop in the final regulations to ensure that the 

fleet-wide standards are achieved in each model year and that by 2016 the fleet average is 

indeed 250 grams per mile. 

[Union of Concerned Scientists also submitted these comments as testimony at the New 

York public hearing, See docket number OAR-2009-0472-4621, pp. 95-98.] 

Natural Resources Defense Council 

GHG Standards Need “Backstop” Standards to Ensure Environmental Objectives Are 

Not Undermined by Shifts in Sales Mix 

The proposed GHG standards lack a regulatory “backstop” mechanism to ensure the 

National Program goals for model year 2016 fleetwide average emission levels and the 

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cumulative greenhouse gas and oil consumption reductions are met (see section I for the 

list of program goals). Such mechanisms are necessary because under an attribute-based 

system that has separate car and light truck standards, the fleet sales mix could shift to 

larger, higher-emitting vehicles and to a greater proportion of light trucks, resulting in 

greater fleetwide emissions and oil consumption thus undermining the achievement of the 

program goals. [OAR-2009-0472-7141.1, p. 8] 

In the proposal, the agencies recognize that attribute-based standards of the proposed 

standards do not guarantee that specific fleetwide GHG emission and fuel economy levels 

will be achieved. Achieving the pollution and oil reduction goals of the program are 

dependent on the overall market achieving the agencies’ forecasted sales and size mixes. 

To reach a fleetwide average of 250 g/mi in model year (MY) 2016, the agencies have set 

the individual car and light truck standards on the assumption of a specific car/light truck 

sales split. However, if the automakers shift their product mix to more light trucks or if 

they change the vehicle designs to classify fewer models as cars and more models as light 

trucks, this car/light truck split would be changed and the GHG and oil savings goals of 

the program would be undermined. This is of particular concern since the agencies’ 

forecast assumes a substantial increase in car sales share, from today’s 50.3 percent to 

66.5 percent by MY 2016.5 Starting in MY 2011, 2WD SUVs will be reclassified as 

cars, which could potentially increase the car portion by 10 percent. However to avoid the 

reclassification, automakers could simply cut back their 2WD SUV offerings. As a 

consequence, the car sales share could be lower than forecast and the National Program’s 

GHG and oil reduction goals would be missed. [OAR-2009-0472-7141.1, pp. 8-9] 

To prevent intentional and unintentional market shifts from undermining the 

environmental and oil savings benefits of the Program, we recommend EPA and NHTSA 

adopt manufacturer-specific backstop combined car and light truck standards that bar an 

individual automaker from exceeding its forecast GHG emission levels by more than 2 

gCO2-equivalent/mi (henceforth referred to as gCO2e/mi). Manufacturer-specific 

backstop standards would ensure that specific manufacturers can be held accountable if 

the overall fleet emission targets are missed. A manufacturer should be allowed no more 

than three years to make up any exceedance in its manufacturer-specific backstop 

standard. [OAR-2009-0472-7141.1, p. 9] 

[NRDC also submitted these comments as testimony at the Detroit public hearing, See 

docket number EPA-HQ-OAR-2009-0472-6185, pp. 20-21.] 

American Council for an Energy Efficient Economy 

The rule should include a provision to ensure that savings are not substantially 

undermined by discrepancies between the future vehicle market and the vehicle market 

projected by the agencies. The extent to which the standards could promote upsizing or 

downsizing of vehicles depends in part upon the shape of the attribute curve. In reducing 

the steepness of the car curve, the agencies have reduced the incentive to upsize vehicles, 

because upsizing a vehicle will not increase the emissions target enough to offset the 

natural tendency of the larger vehicle to consume more fuel (although some distortion of 

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the market through wheelbase manipulation could still occur). At the same time, the new 

standard is not flat enough to promote downsizing, except at the upper and lower ends of 

the size spectrum, which covers a negligible percent of vehicle models. 

The better choice of slope does not however address the issue of car/truck split, which 

presents perhaps the principal way in which the rule could fail to deliver the promised 

emissions reductions. If, for example, instead of reaching 67 percent of the market in 

2016 as the agencies predict, cars remain at the 58 percent share projected for 2011, 

savings attributable to the 2016 standards would be more than 10 percent less than the 

agencies have claimed. 

ACEEE recommends the addition of a “ratchet” mechanism that automatically increases 

the stringency of standards across the board, should emissions reductions fall below a 

predetermined percentage of projected reductions. Such a mechanism would be 

completely compatible with the flexibility offered by an attribute-based system. The need 

for a backstop will be even more evident if the agencies’ approach to setting the level of 

standards is changed to reflect the need to achieve certain levels of GHG emissions, as 

ACEEE recommends. 

Recommendation: Set an upper bound for the level of emissions and fuel consumption 

that can be associated with new light-duty vehicles in a given year. Any exceedence of 

that amount should result in an automatic tightening of the standard to ensure that 

vehicles in the next year will achieve the intended reductions. 

[ACEEE also submitted these comments as testimony at the New York public hearing, 

See docket number EPA-HQ-OAR-2009-0472-4621, p. 139.] 

California State Senate 

I would like the EPA and DOT to develop polices to ensure this program meets its stated 

goals. For example, what happens if a carmaker fails to meet your requirement and can’t 

meet the 2016 target? We are counting on you to achieve the emissions reductions and oil 

savings that we expect from this rule. [OAR-2009-0472-7275.1, p.5] 

[Fran Pavley also submitted these comments as testimony at the Los Angeles public 

hearing. See docket LA EPA Hearing EPA-HQ-OAR-2009-0472-7283, pp. 13-20] 

Sierra Club 

Both agencies should include a backstop in the final rule and we welcome the opportunity 

to comment on this essential element of a strong program. We are concerned that the joint 

proposal’s reliance upon attribute-based curves, whose efficacy will vary with the 

composition of the fleet, imperils the President’s goal of “establishing consistent, 

harmonized, and streamlined requirements” to reduce greenhouse gas emissions and 

improve fuel efficiency. We suggest adopting a backstop rule to prevent shifts of fleet 

composition from undermining the standards and now renew that recommendation. A 

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EPA Response to Comments 

backstop will address weaknesses in the attribute based system and problems that may 

arise with credits – making sure the program stays on course. [OAR-2009-0472-7278.1, 

p.3] 

But the attribute approach, on its own, is imperfect for at least two substantial reasons: 

First, the ultimate effect of the curves is dependent upon the fleet mix. Both agencies 

have assumed a MY 2016 sales fleet mix of 67% cars and 33% trucks, which is a 

dramatic shift from the current 50/50 fleet mix. If assumptions regarding fleet mix 

underestimate the number of larger vehicles sold, then net benefits across the curves will 

be smaller than estimated. According to the Union of Concerned Scientists, a more truck 

heavy fleet mix (42%) would miss the 250 g/mi target by 7 g/mi or nearly 1 mpg and if 

the fleet mix in 2016 is similar to today’s mix, the standard will be missed by 13 g/mi or 

as much as 1.7 mpg. [OAR-2009-0472-7278.1, p.3] 

Second, because the attribute curves for light trucks are set at consistently less ambitious 

levels than those for cars, manufacturers have a strong incentive to attempt to classify 

their cars as ‘light trucks’, thereby escaping the more stringent car curves. As we 

documented in our July 1, 2008, comments on NHTSA’s then-proposed 2011-15 vehicle 

standards, several common vehicles, including the PT Cruiser and Subaru Outback, have 

been so misclassified. While many two-wheel drive compact SUVs will be reclassified 

beginning in MY 2011, manufacturers may opt to shift compact two- [OAR-2009-0472-

7278.1, p.3] wheel drive SUVs to a 4-wheel drive platform keep them on the truck curve, 

affecting the outcome of the program. [OAR-2009-0472-7278.1, p.4] 

To ensure that we achieve 250 g/mi and 34.1 mpg in MY 2016, both agencies 

should include manufacturer-specific, automatic ratchet ‘backstops’ – essentially hard 

fleetwide limits that would undergird the attribute curves, thereby accounting for fleet 

mixes and classifications that had not been predicted. The proposed rule recognizes 

the potential of backstops, acknowledging that “[o]ne way to assure that 

emissions reductions are achieved is through the use of explicit backstops, fleet 

average standards established at an absolute level.” Another option would be to 

require automakers who miss the 2016 targets make up that difference with banked 

credits. Banked credits would be turned into EPA and NHTSA and therefore retired from 

the system and make up for shortfalls. Yet, both EPA and NHTSA fail to adopt this 

simple fail-safe approach save for in the limited case of mileage standards for domestic 

cars. We urge the agencies to reconsider this choice. Below are detailed comments on 

both agencies authority to adopt backstop standards. [OAR-2009-0472-7278.1, p.4] 

The Clean Air Act affords EPA broad discretion to shape its rulemakings to be as 

effective as possible. Section 202(a) of the Act provides that EPA shall propose 

“standards applicable to the emission of any air pollutant from any class of classes of new 

motor vehicles or new motor vehicle engines, which in [EPA’s] judgment cause, or 

contribute, to air pollution which may reasonably be anticipated to endanger public health 

or welfare.28 It gives EPA significant authority to prescribe the precise form of these 

standards, as the proposed rule rightly states.29 So, as the proposed rule states, “[a] 

backstop . . . could be adopted under section 202(a) of the [Clean Air Act].”30 EPA has 

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EPA CO2 Standards 

already described the acute dangers of allowing continued increases in greenhouse gases 

in its proposed endangerment and cause or contribute findings.31 Given that the statute’s 

“primary goal” is “pollution prevention,” (42 U.S.C. §7401(c)), EPA should be taking 

every measure to ensure that its proposed rule successfully drives reductions in the 

vehicular greenhouse gas emissions it has identified as an acute threat to public health 

and welfare. 

EPA’s prior work on setting greenhouse gas standards for vehicle referenced a possible 

“automatic ratchet.” EPA should determine what appropriate annual targets for cars and 

light trucks would be based upon a steady increase to meet the 2016 standards – and, 

indeed, it has already done this in the process of developing its attribute-based curves. 

Second, EPA would include a ‘ratchet’ mechanism in the rule that worked as follows: At 

the end of every year, EPA would determine whether the actual fleet produced in that 

year was consistent with its original predictions. If not, EPA would automatically revise 

the attribute-based curves for the next year to make up the difference. Manufacturers 

would respond by either meeting the new standards directly or by disgorging any credits 

they had earned through over-compliance in past years. In this way, the ‘backstop’ acts 

solely through adjustments in the attribute-based curves. 

For the reasons we have already discussed in these comments, backstop standards help 

ensure that EPA’s goals will be met, acting to buffer the attribute-based curve system 

from unanticipated problems. EPA should adopt this valuable tool. It is, moreover, 

particularly important the EPA do so if NHTSA ultimately does not. Because EPA’s rules 

intertwine with NHTSA’s, EPA could be badly undermined if neither it nor NHTSA put 

a backstop in place. In sum, backstop standards are not hard to write and, if the system 

functions properly, may never need to be implemented. They are a valuable form of lowcost insurance, available to both agencies as they work to help America solve the “urgent 

and closely intertwined challenges of energy independence and global warming.” 

28 42 U.S.C. § 7521(a)(1). 

29 See 74 Federal Register at 49,464 (collecting cases, including NRDC v. EPA, 655 

F.2d 318 (D.C. Cir. 1981)). 

30 74 Federal Register at 49,493; see also id. at 49,513 (describing, correctly, EPA’s 

broad authority to design effective rules). 

31 See generally 74 Federal Register 18,886 (Apr. 24, 2009) at 49,458. We urge EPA and 

NHTSA to take the prudent course and put manufacturer specific, automatic ratchet 

backstops in place. 

[See docket number [OAR-2009-0472-7278.1, pp.10-11] 

[Sierra Club also submitted these comments as testimony at the Detroit public hearing, 

See docket number EPA-HQ-OAR-2009-0472-6185, p. 27.] 

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EPA Response to Comments 

United Auto Workers 

The EPA requested comments on the desirability of establishing alternative backstop 

standards for greenhouse gas emissions. The UAW believes that this is undesirable and 

unnecessary. Doing so would jeopardize the carefully crafted harmonization the agencies 

have achieved under these proposed regulations, eliminating or severely limiting the 

benefits of a unified national program and raising the cost of any particular level of 

regulation. [OAR-2009-0472-7056.1, p.2] 

California Air Resources Board 

The agencies sought comment on whether a backstop should and can be implemented to 

guarantee emission reductions from these attribute-based standards. CARB strongly urges 

the EPA to include a backstop measure in the final rule. The fleet composition in model 

year 2008 – the baseline model year used by the agencies to project fleet composition in 

future years – demonstrated a significant shift in consumer preference to smaller, more 

efficient passenger cars due to an unforeseen increase in fuel prices and a declining 

economy. This shift in consumer preference was also noticeable in the recent “cash for 

clunkers” program. Additional uncertainties in the analysis of future fleet composition 

include: the methodology used by the agencies to project future fleet composition; the 

impact of early credits; future oil prices; and the impact of changing economic 

conditions. A backstop measure would provide assurance that, regardless of any 

unforeseen changes in fleet mix, the GHG emission reductions expected from the 

program would be achieved. 

Contrary to the Alliance’s argument (Document ID EPA-HQ-OAR-2009-0472-6952.1), 

Massachusetts et al. v. EPA said very little about EPA’s and NHTSA’s respective duties, 

did not direct the agencies to avoid inconsistency, and does not preclude EPA from 

promulgating a backstop. 549 U.S. 497, 532 (2007). Rather, the Court merely stated that 

the agencies could fulfill their respective obligations while avoiding the inconsistency. 

This nuanced distinction is important, as the Central Valley and Green Mountain further 

delineated those obligations and found that EPA can fulfill its public health and welfare 

mandate – which a backstop could serve to ensure – while NHTSA fulfills its fuel 

economy mandate. 

In addition, the Alliance’s practical considerations, suggesting a backstop is unnecessary, 

are less than reassuring. First, manufacturers can increase vehicle footprints and offset 

their supposed increased weight penalty by down weighting. Second, manufacturers need 

not change vehicle platforms mid-stream if their sales were originally targeted to larger 

vehicle models than those estimated in the joint proposal. Third, their extreme case of 

offsetting any increase in car efficiency by increasing vehicle footprint is a red herring; 

backstops typically under discussion instead are proposed (as noted above) to preserve 

the greenhouse gas reductions envisioned for this program should any unforeseen 

changes in fleet mix occur. So rather than rely on an industry that has deftly exploited 

regulatory loopholes and marketing tricks to sell larger and heavier vehicles, EPA has an 

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EPA CO2 Standards 

opportunity to ensure that the greenhouse gas emissions it is mandated to achieve actually 

come to fruition. [OAR-2009-0472-7189.1, pp.3-4] 

[CARB also submitted these comments as testimony at the Los Angeles public hearing. 

See docket number OAR-2009-0472-7283, pp. 21-27] 

Center for Biological Diversity 

The Proposed Rule Should Include Backstops to Assure That Minimum Mileage and 

GHG Emission Standards Are Met 

As the court in Center for Biological Diversity determined, although EPCA does not 

explicitly require a backstop to assure that minimum feasible average fuel economy 

standards are met for each model year, the Agencies cannot act arbitrarily or capriciously 

in not adopting a backstop. Id., 508 F.3d at 537-538. See also 49 U.S.C. § 32902(a)(6). 

Moreover, voluntary non-compliance with air pollution standards set under the Clean Air 

Act is not permitted. 

Proposed Rule, 74 Fed. Reg. 49522. In other words, the failure to meet a minimum 

“backstop” pollution standard violates the CAA. Here, the Proposed Rule contemplates 

so many credit swaps, special programs and other loopholes that it cannot predict what 

fuel efficiency standard or GHG emission standard will actually be met in any given 

year....This outcome is impermissible under Center for Biological Diversity, 508 F.3d at 

537-539. The Agencies should set backstops or eliminate all loopholes, credits and other 

mechanisms that allow minimum standards to be flouted. [OAR-2009-0472-7265.1, p. 

18] 

National Automobile Dealers Association (NADA) 

EPA should defer to the CAFE program by not incorporating backstops into its GHG 

rules and by clarifying that it will adjust its mandates as necessary should initial 

feasibility and practicability calculations prove too ambitious. Any failure to do so would 

undermine the concept of a single National Program and, helping to prove the abovestated contention that the issuance of a duplicative EPA standard makes little sense. 

[OAR-2009-0472-7182.1, p.7] 

Non-CO2 light-duty GHGs effectively are regulated by CAFE and, to some extent, even 

by existing tailpipe standards. In light of their de minimis global warming potential 

compared to CO2 separate standards/backstops for non-CO2 GHGs are unnecessary and 

would be redundant. [OAR-2009-0472-7182.1, p.7] 

Connecticut Department of Environmental Protection 

First, DEP supports the proposed emissions standards as cost effective and technically 

feasible. DEP also supports the use of flexible individual manufacturer compliance plans 

as a cost mitigation policy, but believes such plans must- ultimately provide the 

anticipated fuel savings and GHG emission reductions benefits associated with the 

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EPA Response to Comments 

proposed rules. In the event that manufacturers default to widespread vehicle upsizing as 

a compliance strategy, the proposed rules should consider a trigger under which a back 

stop framework (either under the Clean Air Act, or the Energy Independence and 

Security Act) would be implemented. Lacking such a critical assurance, DEP believes 

future coordination among the states, the federal government and vehicle manufacturers 

in the post 2016 timeframe will be difficult to maintain. [OAR-2009-0472-7301, p.2] 

State of New Jersey 

In several places throughout the proposal, the Agencies request commenter input on their 

determination to use attribute-based standards. While we understand why the Agencies 

determined to rely on attribute-based standards when establishing the federal motor 

vehicle control program, the Department is concerned with the attribute-based approach. 

By allowing manufacturers to meet less stringent fuel economy standards through 

expanding the vehicle's footprint, the attribute-based approach could encourage 

manufacturers to produce larger vehicles. 

If this were to occur, the greenhouse gas reductions from the proposed standards may not 

be achieved. In addition, the impact of the civil penalty of $5.50 for each tenth of a mile 

per gallon is negligible for the manufacturers of trucks with larger footprints. These 

concerns could result in manufacturers * shifting to produce larger vehicles, which would 

significantly lessen the estimated greenhouse gas reductions estimated from the 

implementation of this proposal. 

Because of these and other potential concerns, the Department recommends that the 

Agencies establish a backstop measure in its final rulemaking to preserve the estimated 

reductions in greenhouse gas emissions. The backstop could state that a certain fraction 

of the estimated greenhouse gas emission reductions based on the current fleet mix must 

he achieved under these rules or the backstop measure would become effective. [OAR2009-0472-7109.1, p.5] 

Massachusetts Department of Environmental Protection 

Shift of Light-Duty Trucks into the Car Category :A key element of the proposed 

rulemaking is that the increase in MPG and reduction in carbon emissions will be partly 

achieved by shifting most two-wheel drive SUV's into the car category, thereby falling 

under a requirement for higher MPG and lower carbon emissions. Thus, it is projected 

that cars, which are now around 50% of new car sales, will rise to 67% of such sales 

through this adjustment. However, it would be a relatively simple matter for 

manufacturers to avoid this shift by selling more four-wheel drive SUV's relative to two 

wheel-drive vehicles, and to provide consumers with incentives to make such purchases. 

Should this happen, the proportion of light-duty trucks in the fleet might not fall nearly as 

much as EPA and NHTSA are projecting, and overall MPG could be substantially worse 

than the projections in the proposal. 

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EPA CO2 Standards 

Massachusetts believes that EPA and NHTSA should take whatever steps are necessary 

to prevent such a result. One way to do this would be to have a 'backstop' or recalculation of the MPG and emission requirements every couple of years, so that if the 

fleet mix contains a higher proportion of light trucks than is currently forecasted, then 

separate requirements on both categories would be tightened. If this backstop were 

adopted in the final regulations, it could remove any incentive for the manufacturers to 

encourage shifts from two-wheel to four-wheel drive sales, thereby forestalling the need 

to implement the tightened standard. 

[OAR-2009-0472-7195.1, p.2] 

Washington Department of Ecology 

Second, history shows that efficiency and emissions reduction gains from motor vehicle 

emission control can be offset by changes in the fleet mix between passenger cars and 

light duty trucks. For example, the shift from cars to SUVs increased smog-forming 

emissions and led California and EPA to adopt uniform emission standards for most 

passenger vehicles. Ecology urges EPA and NHTSA to consider a potential backstop 

mechanism to preserve the projected GHG reductions over time should the future fleet 

mix change significantly. [OAR-2009-0472-7299, p.2] 

Mass Comment Campaign (2322, unknown organization) 

The best defense would be the establishment of a 'backstop' to preserve oil savings and 

greenhouse gas reductions projected under this program. [OAR-2009-0472-5747, p.1] 

University of Pennsylvania Environmental Law Project 

Another significant problem with the proposed rule is that it is based on uncertain 

projections of future vehicle footprints, vehicle fleet composition, miles driven, and other 

relevant variables. While it is obviously unavoidable to base the policy on uncertain 

future outcomes to some degree, the policy does not guarantee any reduction in 

greenhouse gas emissions. While it is desirable to maintain a degree of flexibility, it is 

also essential that greenhouse gas emissions are significantly curtailed. Thus, the policy 

should create mechanisms whereby minimum reductions are ensured, even if the 

projections turn out to be in significant error. [OAR-2009-0472-7286.1, p. 18] 

American Lung Association of California 

The American Lung Association of California urges the federal EPA to move forward to 

adopt the proposed Clean Cars standard, and to adopt the strengthening changes 

recommended by the Natural Resources Defense Council and the Union of Concerned 

Scientists. These recommendations include: 1) add an automaker specific backstop to 

ensure that the expected level of greenhouse gas emissions reductions are achieved. 

[OAR-2009-0472-7216, p. 2] 

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EPA Response to Comments 

Environment Michigan 

[These comments were submitted as testimony at the Detroit public hearing. See docket 

number EPA-HQ-OAR-2009-0472-6185, p. 69.] 

In addition to addressing these specific issues, we urge you to include a backstop in the 

program that will ensure that the program meets the President's goals for reducing 

pollution and saving oil. 

Environment New Jersey 

And then, finally, we definitely want to make sure there is a backstop in the program to 

make sure the program meets the President's goals for reducing pollution and saving oil. 

[EPA-HQ-OAR-2009-0472-4621, p.76] 

Citizen Kathy Seal 

[These comments were submitted as testimony at the Los Angeles public hearing. See 

docket number OAR-2009-0472-7283, p.148] 

Please consider also the backstop measures to ensure that industry stays on track, the 

backstop measures that I believe other people have already described today on the panels. 

Mass Comment Campaign (326, Student PIRGs) 

President Obama has promised that the standards will cut carbon dioxide pollution by 

950 million metric tons and oil use by 1 .8 billion barrels of oil over the lifetime of the 

vehicles sold under the program. However, the proposed standards include loopholes that 

put these goals at risk. To ensure that the President's goals for reducing pollution and 

cutting oil use are met, please include a backstop in the final rule. [EPA-HQ-OAR-2009-

0472-11293, p. 1] 

EPA Response: 

Whether EPA Has the Statutory Authority to Establish GHG Emissions Backstops 

EPA received only a few comments that directly address the question of whether EPA 

has the statutory authority to establish one or more GHG emissions backstops. Ford 

claimed that EPA’s statutory authority is “highly questionable,” with its main legal 

arguments being that the Clean Air Act does not mention the concept of backstop 

standards, and that backstop standards would yield “two sets of standards” and that “there 

is nothing in the CAA to suggest that Congress intended multiple ‘layers’ of standards to 

apply to vehicle emissions.” The Alliance of Automobile Manufacturers stated that EPA 

authority was “unclear.” Toyota stated that “EPA’s authority may be ambiguous.” 

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EPA CO2 Standards 

On the other hand, Sierra Club emphasized EPA’s “broad discretion” under the CAA and 

argued that EPA does have the authority to establish GHG emissions backstops. Many 

other commenters (see next section) that endorsed GHG emissions backstops presumably 

believe that EPA does have statutory authority in this area, though they did not address 

the legal arguments. 

EPA agrees with the Sierra Club and strongly reaffirms its position from the proposal that 

EPA has the discretion to adopt GHG emissions backstops, where appropriate in light of 

the factors relevant under section 202(a)(1). 

Whether EPA Should Establish GHG Emissions Backstops 

Most of the comments that EPA received on backstops pertained to whether EPA should 

or should not adopt GHG emissions backstops. 

Many commenters supported the establishment of GHG emissions backstops: Northeast 

States for Coordinated Air Use Management, Public Citizen/Safe Climate Campaign, 

Union of Concerned Scientists, Natural Resources Defense Council, American Council 

for an Energy Efficient Economy, California State Senator Fran Pavley, Sierra Club, 

California Air Resources Board, Center for Biological Diversity, Connecticut Department 

of Environmental Protection, State of New Jersey, Massachusetts Department of 

Environmental Protection, Washington Department of Ecology, University of 

Pennsylvania/Environmental Law Project, American Lung Association of California, 

Environment Michigan, Environment New Jersey, and citizen Kathy Seal. EPA also 

received short, “mass comments” from over 2000 private citizens supporting GHG 

emissions backstops. The primary argument of supporters was that backstops were 

necessary, as stated by the Natural Resources Defense Council, “to prevent intentional 

and unintentional market shifts from undermining the environmental and oil savings 

benefits of the Program.” The most common concern cited by many of the commenters 

was that the proposed truck footprint curves yield higher GHG emissions targets than the 

car footprint curves, for the same footprint values, and that this could lead some 

manufacturers to consider changes to increase truck market share and decrease car market 

share. Doing so would decrease the overall GHG savings associated with the standards. 

In addition, some commenters stated that manufacturers might build larger vehicles 

(“upsize”) than EPA projects, for example, because any amount of slope in target curves 

could encourage manufacturers to upsize. 

Some commenters were opposed to GHG emissions backstops: Ford Motor Company, 

Association of International Automobile Manufacturers, Alliance of Automobile 

Manufacturers, Toyota Motor North America, United Auto Workers, and the National 

Automobile Dealers Association. Opponents of backstops argued that upsizing was 

unlikely and emphasized the anti-backsliding characteristics of the target curves (i.e., the 

Alliance of Automobile Manufacturers and Toyota said that upsizing would not 

necessarily make compliance with applicable standards easier, since larger vehicles tend 

to be heavier and heavier vehicles tend to achieve worse fuel economy/emissions levels). 

 Backstop opponents also claimed that universal backstop standards could restrict 

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EPA Response to Comments 

consumer choice of vehicles. Finally, opponents argued that if EPA were to adopt 

backstop standards while NHTSA did not, this would create “new inconsistencies 

between the two programs, rather than further the goal of harmonization” (Ford Motor 

Company). 

EPA is not finalizing GHG emissions backstop standards for the following reasons. 

One, EPA is confident that our projections of the future fleet mix are reliable, and that 

future changes in the fleet mix of footprints and sales as a result of this rule are not likely 

to lead to more than modest changes in projected GHG emissions reductions. The 

agencies acknowledge that based on economic and consumer demand factors that are 

external to this rule, the distribution of footprints in the future may be different (either 

smaller or larger) than what is projected in this rule. However, the agencies continue to 

believe that there will not be significant shifts in this distribution as a direct consequence 

of this rule. 

As explained elsewhere in the rulemaking documents, EPA’s projections of the future 

fleet are based on the most reliable, transparent information currently available. 

Moreover, recent market trends are consistent with EPA’s future fleet projections, 

showing shifts from light trucks to passenger cars and increased emphasis on higher fuel 

economy and lower greenhouse gas emissions. For example, NHTSA’s March 2009 final 

rule establishing MY 2011 CAFE standards was based on a forecast that passenger cars 

would represent 57.6 percent of the MY 2011 fleet, and that MY 2011 passenger cars and 

light trucks would average 45.6 square feet (sf) and 55.1 sf, respectively, such that 

average required CAFE levels would be 30.2 mpg, 24.1 mpg, and 27.3 mpg, respectively, 

for passenger cars, light trucks, and the overall light-duty fleet. Based on EPA and 

NHTSA’s current market forecast, even as soon as MY 2011, passenger cars will 

comprise a larger share (59.2 percent) of the light vehicle market; passenger cars and 

light trucks will, on average, be smaller by 0.5 sf and 1.3 sf, respectively; and average 

required CAFE levels will be higher by 0.2 mpg, 0.3 mpg, and 0.3 mpg, respectively, for 

passenger cars, light trucks, and the overall light-duty fleet. 

Two, EPA does not believe that the risk of changing vehicle offerings to “game” the 

passenger car and light truck definitions is as great as some commenters imply for the 

model years in question. NHTSA’s recent clarification of the light truck definitions, 

which EPA is adopting in its vehicle classifications for the GHG program, has reduced 

the potential for gaming, and resulted in the reclassification of over a million vehicles 

from the light truck to the passenger car fleet. The changes that commenters suggest 

manufacturers might make may not be so simple nor so likely to be accepted by 

consumers. For example, 4WD versions of vehicles tend to be more expensive and, other 

things being equal, have inherently lower fuel economy than their 2WD equivalent 

models. Therefore, although there is a market for 4WD vehicles, and some consumers 

might shift from 2WD vehicles to 4WD vehicles if 4WD becomes available at little or no 

extra cost, many consumers still may not desire to purchase 4WD vehicles because of 

concerns about cost premium and additional maintenance requirements; conversely, 

many manufacturers often require the 2WD option to satisfy demand for base vehicle 

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models. Additionally, increasing the footprint of vehicles involves platform changes, 

which usually requires a product redesign phase. Alternatively, turning many 2WD 

SUVs into 2WD light trucks would require manufacturers to squeeze a third row of seats 

in or significantly increase their GVWR, which also requires a significant change in the 

vehicle’s overall design. 

Three, EPA believes that the shapes of the car and truck footprint curves, including the 

“flattening” at the largest footprint values, tend to avoid or minimize regulatory 

incentives for manufacturers to upsize their fleet to change their compliance burden. 

Given the way the curves are fit to the data points (which represent vehicle models’ GHG 

emissions and fuel economy mapped against their footprint), the agencies believe that 

there is little real benefit to be gained by a manufacturer upsizing its vehicles. The 

agencies’ analysis indicates that, for passenger car models with footprints falling between 

the two flattened portions of the car footprint curve, the actual slope of fuel economy 

with respect to footprint, if fit to that data by itself, is about 27 percent steeper than the 

curve being promulgated today. This difference suggests that manufacturers would, if 

anything, ease their compliance burden by reducing vehicle footprint than by increasing 

vehicle footprint. For light trucks, the agencies’ analysis indicates that, for models with 

footprints falling between the two flattened portions of the corresponding curve, the slope 

of fuel economy with respect to footprint is nearly identical to the curve being 

promulgated today. This suggests that, within this range, manufacturers would typically 

have little incentive to either incrementally increase or reduce vehicle footprint. A 

number of commenters, including Honda, affirmed that this is the case. 

At the same time, adding another backstop standard would have virtually no effect if the 

standard was weak, but a more stringent backstop could compromise the objectives 

served by attribute-based standards – that they distribute compliance burdens more 

equally among manufacturers, and at the same time encourage manufacturers to apply 

fuel-saving technologies rather than simply downsizing their vehicles, as they did in past 

decades under flat standards. This is why Congress mandated attribute-based CAFE 

standards in EISA. This compromise in objectives could occur for any manufacturer 

whose fleet average was above the backstop, irrespective of why they were above the 

backstop and irrespective of whether the industry as a whole was achieving the emissions 

and fuel economy benefits projected for the final standards, the problem the backstop is 

supposed to address. For example, the projected industry wide level of 250 gm/mile for 

MY 2016 is based on a mix of manufacturer levels, ranging from approximately 205 to 

315 gram/mile5

 but resulting in an industry wide basis in a fleet average of 250 gm/mile. 

Unless the backstop was at a very weak level, above the high end of this range, then some 

percentage of manufacturers would be above the backstop even if the performance of the 

entire industry remains fully consistent with the emissions and fuel economy levels 

projected for the final standards. For these manufacturers and any other manufacturers 

who were above the backstop, the objectives of an attribute based standard would be 

compromised and unnecessary costs would be imposed. This could directionally impose 

increased costs for some manufacturers. It would be difficult if not impossible to 

establish the level of a backstop standard such that costs are likely to be imposed on 

 

5

 Based on estimated standards presented in Preamble tables III.B.1-1 and III.B.1-2. 

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EPA Response to Comments 

manufacturers only when there is a failure to achieve the projected reductions across the 

industry as a whole. See comments from Ford Motor Company above supporting this 

reasoning. An example of this kind of industry wide situation could be when there is a 

significant shift to larger vehicles across the industry as a whole, or if there is a general 

market shift from cars to trucks. The problem the agencies are concerned about in those 

circumstances is not with respect to any single manufacturer, but rather is based on 

concerns over shifts across the fleet as a whole, as compared to shifts in one 

manufacturer's fleet that may be more than offset by shifts the other way in another 

manufacturer's fleet. However, in this respect, a traditional backstop acts as a 

manufacturer specific standard. 

While the simplest form of GHG emissions backstop is a universal standard, i.e., a single 

gram/mile level that no manufacturer could exceed, a few commenters suggested 

alternative GHG emissions backstop approaches. The most common alternative 

approach suggested by commenters was an industry-wide “trigger” or “ratchet” approach, 

whereby EPA would build into the standards an automatic lowering or flattening of the 

GHG-footprint curves if the industry-wide model mix and footprint characteristics 

changed sufficiently to reduce the actual GHG emissions savings relative to the projected 

GHG emissions savings. The concept of a ratchet mechanism recognizes the problem 

discussed above,, and would impose the new more stringent standard only when the 

problem arises across the industry as a whole. While the new more stringent standards 

would enter into force automatically, any such standards would still need to provide 

adequate lead time for the manufacturers. Given the short lead-time already before the 

2012 model year, a ratchet mechanism in this rulemaking that would automatically 

tighten the standards at some point after model year 2012 is finished and apply the new 

more stringent standards for model years 2016 or earlier, would fail to provide adequate 

lead time for any new, more stringent standards. Since the GHG emissions standards 

remain in effect unless and until they are changed, there would be greater lead time for 

future years beyond model year 2016. However, as discussed below, EPA believes the 

better course is to monitor model mix and footprint characteristics, and associated GHG 

emissions reductions, and reconsider this issue in the future if a problem arises. 

EPA believes that it has ample reasons to choose not to exercise its discretion under 

section 202 (a) (1) to adopt a backstop. EPA consequently disagrees with the Center for 

Biological Diversity that any choice not to adopt a backstop would be impermissibly 

arbitrary. 

Although EPA is not adopting GHG emissions backstops, EPA plans to conduct and 

document retrospective analyses to evaluate the model mix and footprint characteristics 

of the future fleet during the rulemaking timeframe and to compare these characteristics 

to what EPA has projected in this rulemaking analysis. If EPA determines that there is a 

significant shift in the industry’s product mix resulting in a relaxation of their estimated 

targets and overall GHG emissions savings, EPA will reconsider the relative merits of 

GHG emissions backstops in future rulemakings under the CAA. 

 

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