U.S. Department 

Of Transportation

PRELIMINARY REGULATORY IMPACT ANALYSIS

CORPORATE AVERAGE FUEL 

ECONOMY FOR 

MY 2011-2015 

PASSENGER CARS and 

LIGHT TRUCKS 

Office of Regulatory Analysis and Evaluation 

National Center for Statistics and Analysis 

April 2008 
TABLE OF CONTENTS 

 

Executive Summary.........................................................................................i 

I. Introduction........................................................................................ I-1 

II. Need of the Nation to Conserve Energy ............................................II-1 

III. Regulatory Alternatives ....................................................................III-1 

IV. Impact of Other Motor Vehicle Standards on Fuel Economy ..........IV-1 

Vehicle Size and Safety ....................................................................IV-7 

The Impact of Emission Standards ..................................................IV-18 

V. Fuel Economy Enhancing Technologies and the Volpe Model........ V-1 

The Volpe Model ............................................................................. V-52 

Penetration of Technologies by Alternative ................................... V-127 

VI. Manufacturer Specific CAFE Capabilities .......................................VI-1 

VII. Cost Impacts..................................................................................... VII-1 

The Impact of Higher Prices on Sales ........................ .........VII-41 

Potential Impact on Employment .......................................VII-53 

VIII. Benefits .......................................................................................... VIII-1 

Discount Rate.................................................................................. VIII-1 

Sales Projections ............................................................................. VIII-3 

The “Rebound Effect”..................................................................... VIII-5 

On-Road Fuel Economy Adjustment....................................VIII-8 

Benefits from Fuel Savings............................................................. VIII-9 

Other Economic Benefits from Reducing Petroleum Use ............. VIII-21 
TABLE OF CONTENTS cont. 

Emissions Reductions Resulting from Fuel Savings ..................... VIII-25 

Summary of Benefits .................................................................... VIII-36 

IX. Net Benefits and Sensitivity Analysis...............................................IX-1 

Payback Period.................................................................................IX-14 

X. Probabilistic Uncertainty Analysis ................................................... X-1 

XI. Regulatory Flexibility Act and Unfunded Mandates Reform Act ...XI-1 

Appendix A: Required MPG Levels............................................................ A-1 
i

EXECUTIVE SUMMARY 

This assessment examines the costs and benefits of improving the fuel economy of passenger 

cars and light trucks for model years (MY) 2011- 2015. It includes a discussion of the 

technologies that can improve fuel economy, analysis of the potential impact on retail prices, 

safety, lifetime fuel savings and their value to consumers, and other societal benefits such as 

improved energy security and reduced emissions of pollutants and greenhouse gases1. 

In the previous rulemaking, the agency reformed the corporate average fuel economy (CAFE) 

standards for light trucks with a size-based standard based on footprint2. This rulemaking 

continues this approach for both passenger cars and light trucks. A continuous mathematical 

function provides a separate fuel economy target for each footprint. Different parameters for the 

continuous mathematical function are derived for each model year. Individual manufacturers 

will be required to comply with a single fuel economy level that is based on the distribution of its 

production among the footprints of its vehicles in each particular model year. Although the same 

reformed CAFE scheme is proposed for both passenger cars and light trucks, they are established 

with different continuous mathematical functions specific to their design capabilities. 

The agency is proposing the “Optimized (7%)” alternative. In this alternative the agency uses a 

7 percent discount rate to value benefits and sets the proposed mpg levels where marginal costs 

equal marginal benefits. It is one of six alternatives examined in the analysis. We also examined 

a second optimized scenario when discounting benefits at 3 percent “Optimized (3%). In general 

order of increasing severity (see Table 1), the seven scenarios examined are: 

1: “25% Below Optimized”: This alternative mirrors the absolute difference in mpg derived 

from the 25% Above Optimized scenario in going the same mpg amount below the Optimized 

7% alternative 

2: “Optimized (7%) An increase in the standard based upon availability of technologies and a 

marginal cost/benefit analysis, as was used in setting the MY 2008-2011 light truck standard. 

The mpg levels are set using a 7 percent discount rate for benefits. 

3: “25% Above Optimized”: This alternative looks at the mpg levels of the Optimized (7%) 

and the Total Cost Equals Total Benefit alternative and picks mpg levels that are 25 percent of 

that difference. 

 

1

 This analysis does not contain NHTSA’s assessment of the potential environmental impacts of the proposed 

standards and reasonable alternatives for purposes of the National Environmental Policy Act (NEPA), 42 U.S.C. 

4321-4347. On March 28, 2008, NHTSA published a notice of intent to prepare an environmental impact statement 

(EIS) and opened the NEPA scoping process (73 FR 16615). NHTSA will consider the potential environmental 

impacts of the proposed standards and reasonable alternatives through the NEPA process, and NHTSA’s NEPA 

analysis will inform any further action on the proposed standards, consistent with NEPA and EPCA. 

2

 Vehicle Footprint is defined as the wheelbase (the distance from the center of the front axle to the center of the 

rear axle) times the average track width (the distance between the centerline of the tires) of the vehicle (in square 

feet). 
ii

4: “50% Above Optimized”: This alternative looks at the mpg levels of the Optimized (7%) 

and the Total Cost Equals Total Benefit alternative and picks mpg levels that are 50 percent of 

that difference. 

5: “Optimized (3%) An increase in the standard based upon availability of technologies and a 

marginal cost/benefit analysis, as was used in setting the MY 2008-2011 light truck standard, 

except that the mpg levels are set using a 3 percent discount rate for benefits. 

6: “Total Costs Equal Total Benefits”: An increase in the standard to a point where essentially 

total costs of the technologies added equals total benefits. In this analysis, for brevity, at times it 

is labeled “TC = TB”. 

7: “Technology Exhaustion”: An increase in the standard based upon the maximum usage 

(based on NHTSA’s perspective) of available technologies, disregarding the cost impacts. 

 

Table 1a shows the agency’s projection of the actual harmonic average that would be achieved 

by the manufacturers, assuming those manufacturers whose plans are above the requirements 

would achieve those higher levels. Table 1b shows the estimated required levels. All of the 

tables in this analysis compare an adjusted baseline to the achieved harmonic average in Table 

1a. 

 

Costs: Costs were estimated based on the specific technologies that were applied to improve 

each manufacturer’s fuel economy up to the level required under each alternative. Table 2 

provides those cost estimates on an average per-vehicle basis, and Table 3 provides those 

estimates on a fleet-wide basis in millions of dollars. Costs are not discounted. 

Benefits: Benefits are determined mainly from fuel savings over the lifetime of the vehicle, but 

also include externalities such as reductions in criteria pollutants. Table 4 provides those 

estimates on an industry-wide basis. 

Net Benefits: Table 5 compares costs and benefits of each alternative. The values in Table 5 

compare societal benefits to societal costs of each alternative. Thus, it does not use the values of 

Table 2, which include fines paid by manufacturers and transferred to consumers to pay. 

Fuel Savings: Table 6 shows the lifetime fuel savings in millions of gallons. 
iii

Table 1a 

Alternative CAFE Levels 

Projected Harmonic Average for the Fleet3

(in mpg) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

25% Below Optimized 30.5 31.2 31.9 32.8 33.5 

Optimized (7%) 31.0 32.3 33.1 33.9 34.7 

25% Above Optimized 31.5 33.3 34.2 35.3 36.1 

50% Above Optimized 31.7 34.0 35.1 36.4 37.6 

Optimized (3%) 32.2 34.5 35.5 37.0 38.2 

TC = TB 32.3 35.0 36.1 37.6 38.8 

Technology Exhaustion 32.3 35.2 36.6 38.5 39.9 

 

Light Trucks 

25% Below Optimized 24.3 25.5 27.3 27.3 27.4 

Optimized (7%) 24.4 25.8 27.5 28.0 28.4 

25% Above Optimized 24.4 26.1 27.8 28.5 29.5 

50% Above Optimized 24.6 26.3 28.0 28.9 30.0 

Optimized (3%) 24.4 25.8 27.7 28.2 28.8 

TC = TB 24.7 26.5 28.5 29.5 30.5 

Technology Exhaustion 24.7 26.6 29.4 30.3 31.3 

 

3

 The values represent the higher of the manufacturer’s plans and the alternative level of the standard. 
iv

Table 1b 

Estimated Required Average for the Fleet 

(in mpg) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

25% Below Optimized 29.6 30.3 31.7 32.7 33.9 

Optimized (7%) 31.2 32.8 34.0 34.8 35.7 

25% Above Optimized 32.8 35.3 36.1 36.8 37.5 

50% Above Optimized 34.3 37.8 38.5 38.9 39.5 

Optimized (3%) 37.1 39.1 39.3 40.7 40.9 

TC = TB 37.5 42.7 43.0 43.1 43.3 

Technology Exhaustion 38.6 45.4 48.9 50.1 52.6 

 

Light Trucks 

25% Below Optimized 24.9 26.0 27.5 27.5 27.5 

Optimized (7%) 25.0 26.4 27.8 28.2 28.6 

25% Above Optimized 25.1 26.9 28.0 28.8 29.8 

50% Above Optimized 25.3 27.3 28.3 29.5 30.9 

Optimized (3%) 25.0 26.4 28.0 28.5 29.0 

TC = TB 25.6 28.1 28.8 30.8 33.1 

Technology Exhaustion 25.9 28.6 32.2 33.1 34.7 

See Appendix A for more information on the required levels. 
v

Table 2 

Average Incremental Cost 

Per Vehicle – Consumer Perspective 

(2006 Dollars) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

25% Below Optimized 126 126 187 294 428 

Optimized (7%) 276 334 404 512 649 

25% Above Optimized 494 778 871 1,078 1,185 

50% Above Optimized 620 1,133 1,251 1,501 1,694 

Optimized (3%) 896 1,284 1,376 1,706 1,915 

TC = TB 966 1,685 1,829 2,159 2,367 

Technology Exhaustion 1,038 2,032 2,406 2,889 3,264 

 

Light Trucks 

25% Below Optimized 185 526 738 705 708 

Optimized (7%) 224 617 861 924 979 

25% Above Optimized 279 873 1,141 1,352 1,655 

50% Above Optimized 385 1,008 1,347 1,644 2,041 

Optimized (3%) 227 616 955 1,028 1,145 

TC = TB 501 1,325 1,770 2,171 2,509 

Technology Exhaustion 536 1,364 2,255 2,507 2,785 
vi

Table 3 

Incremental Total Cost – Consumer Perspective 

(Millions of 2006 Dollars) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 5 year total

25% Below Optimized 835 818 1,253 2,153 3,209 8,268

Optimized (7%) 1,884 2,373 2,879 3,798 4,862 15,796

25% Above Optimized 3,387 5,653 6,445 8,240 9,084 32,808

50% Above Optimized 4,010 7,885 8,986 11,207 12,981 45,070

Optimized (3%) 5,467 8,791 9,821 12,447 14,484 51,011

TC = TB 5,913 10,796 12,303 15,403 17,398 61,812

Technology Exhaustion 6,079 12,595 14,701 18,759 21,110 73,245

 

Light Trucks 

25% Below Optimized 1,349 4,296 6,329 6,212 6,326 24,512

Optimized (7%) 1,649 4,986 7,394 8,160 8,761 30,949

25% Above Optimized 2,072 7,034 9,815 11,903 14,781 45,606

50% Above Optimized 2,922 8,098 11,586 14,386 17,969 54,961

Optimized (3%) 1,662 4,974 8,190 9,058 10,253 34,136

TC = TB 3,788 10,525 15,196 18,762 21,364 69,635

Technology Exhaustion 3,933 10,670 18,275 21,051 23,479 77,408

 

Combined PC +LT 

25% Below Optimized 2,184 5,114 7,582 8,365 9,534 32,780

Optimized (7%) 3,534 7,358 10,273 11,957 13,623 46,745

25% Above Optimized 5,459 12,687 16,261 20,143 23,865 78,414

50% Above Optimized 6,932 15,983 20,572 25,593 30,950 100,030

Optimized (3%) 7,128 13,765 18,011 21,505 24,737 85,147

TC = TB 9,702 21,321 27,499 34,164 38,761 131,447

Technology Exhaustion 10,013 23,266 32,976 39,810 44,589 150,653
vii

Table 4a 

Present Value of Lifetime Societal Benefits by Alternative 

(Millions of 2006 Dollars) 

 (Discounted 3%) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 Total 5 years

25% Below Optimized 1,418 2,581 3,977 6,399 8,387 22,762

Optimized (7%) 3,181 6,054 7,561 9,716 11,616 38,128

25% Above Optimized 4,604 8,939 10,403 13,109 14,907 51,962

50% Above Optimized 5,241 10,842 12,571 15,503 17,893 62,050

Optimized (3%) 6,798 12,188 13,519 16,833 19,216 68,554

TC = TB 7,075 13,366 14,881 18,059 20,364 73,745

Technology Exhaustion 7,156 13,865 15,967 19,654 22,312 78,954

 

Light Trucks 

25% Below Optimized 4,414 9,959 15,910 15,715 15,745 61,743

Optimized (7%) 4,919 11,055 17,120 18,866 20,506 72,466

25% Above Optimized 5,286 12,599 17,972 20,984 24,662 81,503

50% Above Optimized 5,848 13,249 18,955 22,375 26,475 86,902

Optimized (3%) 4,939 11,075 17,976 19,902 22,246 76,138

TC = TB 6,343 14,452 20,631 24,704 28,352 94,482

Technology Exhaustion 6,420 14,528 24,517 27,951 31,387 104,803

 

Passenger Cars and Light Trucks Combined 

25% Below Optimized 5,832 12,540 19,887 22,114 24,132 84,505

Optimized (7%) 8,100 17,109 24,681 28,582 32,122 110,594

25% Above Optimized 9,890 21,538 28,375 34,093 39,569 133,465

50% Above Optimized 11,089 24,091 31,526 37,878 44,368 148,952

Optimized (3%) 11,737 23,263 31,495 36,735 41,462 144,692

TC = TB 13,418 27,818 35,512 42,763 48,716 168,227

Technology Exhaustion 13,576 28,393 40,484 47,605 53,699 183,757
viii

Table 4b 

Present Value of Lifetime Societal Benefits by Alternative 

(Millions of 2006 Dollars) 

(Discounted 7%) 

Passenger Car MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 Total 5 years

25% Below Optimized 1,156 2,104 3,235 5,197 6,799 18,491

Optimized (7%) 2,596 4,933 6,148 7,889 9,420 30,986

25% Above Optimized 3,755 7,280 8,454 10,638 12,083 42,210

50% Above Optimized 4,274 8,825 10,213 12,576 14,495 50,383

Optimized (3%) 5,543 9,922 10,983 13,654 15,569 55,671

TC = TB 5,769 10,878 12,087 14,644 16,492 59,870

Technology Exhaustion 5,834 11,282 12,968 15,930 18,061 64,075

 

Light Trucks 

25% Below Optimized 3,508 7,910 12,603 12,432 12,441 48,894

Optimized (7%) 3,909 8,779 13,560 14,915 16,192 57,355

25% Above Optimized 4,201 9,990 14,236 16,587 19,457 64,471

50% Above Optimized 4,642 10,507 15,011 17,687 20,892 68,739

Optimized (3%) 3,926 8,794 14,251 15,752 17,589 60,312

TC = TB 5,027 11,453 16,330 19,515 22,367 74,692

Technology Exhaustion 5,088 11,513 19,395 22,074 24,759 82,829

 

Passenger Cars and Light Trucks Combined 

25% Below Optimized 4,664 10,014 15,838 17,629 19,240 67,385

Optimized (7%) 6,505 13,712 19,708 22,804 25,612 88,341

25% Above Optimized 7,956 17,270 22,690 27,225 31,540 106,681

50% Above Optimized 8,916 19,332 25,224 30,263 35,387 119,122

Optimized (3%) 9,469 18,716 25,234 29,406 33,158 115,983

TC = TB 10,796 22,331 28,417 34,159 38,859 134,562

Technology Exhaustion 10,922 22,795 32,363 38,004 42,820 146,904
ix

Table 5a 

Net Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

Societal Perspective 

(Millions of 2006 Dollars) 

(Discounted 3%) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 Total 5 years

25% Below Optimized 583 1,763 2,724 4,246 5,178 14,494

Optimized (7%) 1,297 3,681 4,682 5,918 6,754 22,332

25% Above Optimized 1,217 3,286 3,958 4,869 5,823 19,154

50% Above Optimized 1,231 2,957 3,585 4,296 4,912 16,980

Optimized (3%) 1,331 3,397 3,698 4,386 4,732 17,543

TC = TB 1,162 2,570 2,578 2,656 2,966 11,933

Technology Exhaustion 1,077 1,270 1,266 895 1,202 5,709

Light Trucks 

25% Below Optimized 3,065 5,663 9,581 9,503 9,419 37,231

Optimized (7%) 3,270 6,069 9,726 10,706 11,745 41,517

25% Above Optimized 3,214 5,565 8,157 9,081 9,881 35,897

50% Above Optimized 2,926 5,151 7,369 7,989 8,506 31,941

Optimized (3%) 3,277 6,101 9,786 10,844 11,993 42,002

TC = TB 2,555 3,927 5,435 5,942 6,988 24,847

Technology Exhaustion 2,487 3,858 6,242 6,900 7,908 27,395

Passenger Cars and Light Trucks Combined 

25% Below Optimized 3,648 7,426 12,305 13,749 14,598 51,725

Optimized (7%) 4,566 9,751 14,408 16,625 18,499 63,849

25% Above Optimized 4,431 8,851 12,114 13,950 15,704 55,051

50% Above Optimized 4,157 8,108 10,954 12,285 13,418 48,922

Optimized (3%) 4,609 9,498 13,484 15,230 16,725 59,545

TC = TB 3,716 6,497 8,013 8,599 9,955 36,780

Technology Exhaustion 3,563 5,127 7,508 7,795 9,110 33,104
x

Table 5b 

Net Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

Societal Perspective 

(Millions of 2006 Dollars) 

(Discounted 7%) 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 Total 5 years

25% Below Optimized 321 1,286 1,982 3,044 3,590 10,223

Optimized (7%) 712 2,560 3,269 4,091 4,558 15,190

25% Above Optimized 368 1,627 2,009 2,398 2,999 9,402

50% Above Optimized 264 940 1,227 1,369 1,514 5,313

Optimized (3%) 76 1,131 1,162 1,207 1,085 4,660

TC = TB -144 82 -216 -759 -906 -1,942

Technology Exhaustion -245 -1,313 -1,733 -2,829 -3,049 -9,170

Light Trucks 

25% Below Optimized 2,159 3,614 6,274 6,220 6,115 24,382

Optimized (7%) 2,260 3,793 6,166 6,755 7,431 26,406

25% Above Optimized 2,129 2,956 4,421 4,684 4,676 18,865

50% Above Optimized 1,720 2,409 3,425 3,301 2,923 13,778

Optimized (3%) 2,264 3,820 6,061 6,694 7,336 26,176

TC = TB 1,239 928 1,134 753 1,003 5,057

Technology Exhaustion 1,155 843 1,120 1,023 1,280 5,421

Passenger Cars and Light Trucks Combined 

25% Below Optimized 2,480 4,900 8,256 9,264 9,706 34,605

Optimized (7%) 2,971 6,354 9,435 10,847 11,989 41,596

25% Above Optimized 2,497 4,583 6,429 7,082 7,675 28,267

50% Above Optimized 1,984 3,349 4,652 4,670 4,437 19,092

Optimized (3%) 2,341 4,951 7,223 7,901 8,421 30,836

TC = TB 1,094 1,010 918 -5 98 3,115

Technology Exhaustion 909 -471 -613 -1,806 -1,769 -3,749

Negative values mean that societal costs exceed societal benefits. 
xi

Table 6 

Savings in Millions of Gallons of Fuel 

Undiscounted Over the Lifetime of the Model Year 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 Total 5 years

25% Below Optimized 708 1,261 1,946 3,135 4,151 11,201

Optimized (7%) 1,563 2,968 3,717 4,771 5,716 18,735

25% Above Optimized 2,313 4,480 5,221 6,601 7,476 26,091

50% Above Optimized 2,641 5,523 6,422 7,913 9,121 31,620

Optimized (3%) 3,463 6,197 6,905 8,587 9,784 34,936

TC = TB 3,599 6,860 7,676 9,320 10,461 37,916

Technology Exhaustion 3,677 7,143 8,261 10,233 11,562 40,876

 

Light Trucks 

25% Below Optimized 2,157 4,933 7,902 7,799 7,808 30,599

Optimized (7%) 2,404 5,478 8,509 9,392 10,195 35,978

25% Above Optimized 2,585 6,339 9,070 10,592 12,534 41,120

50% Above Optimized 2,909 6,780 9,697 11,458 13,584 44,428

Optimized (3%) 2,414 5,488 8,978 9,959 11,127 37,966

TC = TB 3,228 7,471 10,640 12,778 14,602 48,719

Technology Exhaustion 3,263 7,506 12,659 14,448 16,147 54,023

 

Passenger Cars and Light Trucks Combined 

25% Below Optimized 2,865 6,194 9,848 10,934 11,959 41,800

Optimized (7%) 3,967 8,446 12,226 14,163 15,911 54,713

25% Above Optimized 4,898 10,819 14,291 17,193 20,010 67,211

50% Above Optimized 5,550 12,303 16,119 19,371 22,705 76,048

Optimized (3%) 5,877 11,685 15,883 18,546 20,911 72,902

TC = TB 6,827 14,331 18,316 22,098 25,063 86,635

Technology Exhaustion 6,940 14,649 20,920 24,681 27,709 94,899
I-1

I. INTRODUCTION 

The purpose of this study is to analyze the effects of changes in the fuel economy standards for 

passenger cars and for light trucks from MY 2011 to MY 2015. It includes a discussion of the 

technologies that can improve fuel economy, the potential impacts on retail prices, safety, the 

discounted lifetime net benefits of fuel savings, and the potential gallons of fuel saved. 

The agency issued a final rule on April 7, 2003 (68 FR 16868), setting the CAFE standard 

applicable to light trucks for MY 2005 at 21.0 mpg, for MY 2006 at 21.6 mpg, and for MY 2007 

at 22.2 mpg. On April 6, 2006 (71 FR 17566), the agency issued a final rule for MYs 2008 to 

2011 under a new “CAFE Reform” structure. Similar to this report, a Final Regulatory Impact 

Analysis accompanied that final rule.4

 Much of the technical and cost information used in the 

2006 analysis was taken from the findings in the National Academy of Sciences study5

 published 

in January 2002. 

The new attribute-based Reformed CAFE system is based on the vehicle footprint (wheel base6

 x 

average wheel track width7

). The anticipated advantages of the new reformed CAFE system are: 

First, the energy-saving potential of the CAFE program was hampered by the original regulatory 

structure. Manufacturers who offer predominately small vehicles had little or no regulatory 

incentive to enhance fuel economy, because their vehicles tend to be more fuel efficient than the 

CAFE level. Moreover, the difference between the fuel economy standards for passenger cars 

and light trucks (27.5 mpg and 20.7 mpg, respectively, for MY 2004) encouraged vehicle 

manufacturers to offer vehicles classified as light trucks for purposes of CAFE, possibly 

inducing design changes that hurt overall fuel economy. A CAFE system that more closely links 

fuel economy standards to the various market segments and their fuel economy performance may 

reduce the incentive to design vehicles which are functionally similar to passenger cars but are 

classified as light trucks. 

Second, we were concerned that the original light truck CAFE standards could create safety 

risks. Vehicle manufacturers are encouraged to achieve greater fuel economy by downsizing and 

downweighting. Alternatively, manufacturers may offer small vehicles to offset their offerings 

of large vehicles. The resulting increase in the disparity between the smallest and largest vehicle 

sizes and weights in the on-road vehicle fleet is widely believed to have increased the number of 

fatalities in crashes involving passenger cars and light-duty trucks. The National Academy of 

Sciences (NAS) report and a NHTSA study8

 have suggested that if downweighting were 

concentrated on the heaviest vehicles in the fleet, there could be a small fleetwide safety benefit, 

but downweighting of passenger cars and the lighter light trucks would increase fatalities. 

 

4

 “Final Regulatory Impact Analysis, Corporate Average Fuel Economy and CAFE Reform for MY 2008-2011 

Light Trucks”, March 2006, Docket No. 24309-5. 

5

 “Effectiveness and Impact of Corporate Average Fuel Economy (CAFE) Standards”, National Research Council, 

2002. The link for the NAS report is http://www.nap.edu/books/0309076013/html/ 6

 “Wheel base” is essentially the distance between the centers of the axles. 7

 “Track width” is the lateral distance between the centerline of the tires. 8

 “Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 Passenger Cars and Light 

Trucks”, Charles J. Kahane, Ph.D., NHTSA, October 2003, DOT HS 809-662. 
I-2

A third reason for considering CAFE reform relates to the adverse economic impacts that may 

result from such future increases in the stringency of CAFE standards. Rapid increases in the 

level of the CAFE standard could have substantial economic consequences on manufacturers, 

especially those full-line manufacturers with product mixes dominated by large heavier vehicles. 

For example, full-line manufacturers – especially those with substantial sales in the heavier end 

of the light truck market – may generate fewer CAFE credits and incur larger compliance costs 

than vehicle manufacturers who focus their sales in the smaller, lighter end of the light truck 

market. As CAFE standards become more stringent under the original structure, the full-line 

manufacturers may experience adverse financial consequences, with resulting disruptions for 

employees in these firms and their suppliers. 

EPCA also gives NHTSA authority to set passenger car CAFE standards for each model year, 

but sets a default standard of 27.5 mpg. NHTSA has not raised the passenger car CAFE standard 

from 27.5 mpg since Congress lifted the ban on CAFE rulemakings in 2002 because it did not 

believe that it had authority to reform passenger car CAFE as it had for light trucks. Reforming 

the CAFE program achieves larger fuel savings while enhancing safety and preventing adverse 

economic consequences—objectives which apply equally to passenger cars as to light trucks. 

NHTSA was unwilling to raise the passenger car CAFE standard without also reforming it, 

because of the same fuel savings, safety, and economic concerns that led it to reform the light 

truck CAFE standards. 

In December 2007, Congress passed the Energy Independence and Security Act (EISA). EISA 

mandates the setting of separate standards for passenger cars and for light trucks at levels 

sufficient to ensure that the average fuel economy of the combined fleet of all passenger cars and 

light trucks sold by all manufacturers in the U.S. in model year 2020 equals or exceeds 35 miles 

per gallon. That is a 40 percent increase above the average of approximately 25 miles per gallon 

for the current combined fleet. 

This notice proposes standards for model years (MY) 2011-2015, the maximum number of 

model years under EISA for which NHTSA can establish standards in a single rulemaking. 

However, the Act gives NHTSA authority to reform passenger car CAFE, allowing the agency to 

set standards for those vehicles according to an attribute-based mathematical function as it 

currently does for light trucks. 

The dual fuel incentive program, through which manufacturers may improve their calculated fuel 

economies by producing vehicles capable of operating on alternative fuels, is not considered in 

this analysis. By law, the agency has always analyzed fuel economy without considering the 

dual fuel credits, since it is an incentive program designed to increase the availability of 

alternative fuel vehicles. 

Throughout this analysis, unless otherwise noted, the agency has not considered the ability of 

manufacturers to use credits or credit trading in achieving the alternative fuel economy levels. 

Throughout this document, confidential information is presented in brackets [ ].
II-1

II. NEED OF THE NATION TO CONSERVE ENERGY

The Energy Policy and Conservation Act (EPCA) states that: 

“When deciding maximum feasible average fuel economy ... the Secretary of 

Transportation shall consider technological feasibility, economic practicability, the 

effect of other motor vehicle standards of the Government on fuel economy, and the 

need of the United States to conserve energy.”9

Thus, (EPCA) specifically directs the Department to balance the technological and economic 

challenges related to fuel economy with the nation's need to conserve energy. The concerns 

about energy security and the effects of energy prices and supply on national economic wellbeing that led to the enactment of EPCA persist today. The demand for petroleum is steadily 

growing in the U.S. and around the world. 

Since 1970, there have been a series of events that suggest that the behavior of petroleum 

markets is a matter for public concern. 

• Crude oil prices are currently in the neighborhood of $100 per barrel. As recently as 

1998, crude prices averaged about $13 per barrel ($15.85 in 2006 dollars).10 Gasoline 

prices have more than doubled during this period.11

• U.S. domestic oil production peaked in 1970 at 11.3 million barrels per day. Between 

1970 and 2006, U.S. domestic production has declined by nearly 40 percent, while U.S. 

petroleum consumption has increased by 40 percent. Net petroleum imports now account 

for 60 percent of U.S. domestic petroleum consumption.12 

• Worldwide oil demand is very inelastic: declining prices do not induce large increases in 

consumption, while higher prices do not restrain consumption. Thus, relatively minor 

changes in quantity demanded can induce large changes in price. Within the United 

States, demand for gasoline, diesel, and jet fuel within the transportation sector is 

particularly inelastic. 

• Demand for oil may increase significantly in Asia and worldwide in the future resulting 

in competition for oil supplies. 

• Oil production facilities, refineries, and supply chains have been disrupted from time to 

time, either by wars, political action by oil producers, civil unrest, or natural disasters. 

• High oil prices, sometimes induced by disruptions in oil markets, have often coincided 

with rising inflation and subsequent economic recessions. 

 

9

 49 USC 32902(f) 

10 Energy Information Administration, Annual Energy Review 2006, Table 5.21, p. 171. See: 

http://www.eia.doe.gov/emeu/aer/pdf/pages/sec5_51.pdf

11 Energy Information Administration, Annual Energy Review 2006, Table 5.24, p. 177. See: 

http://www.eia.doe.gov/emeu/aer/pdf/pages/sec5_57.pdf

12 Energy Information Administration, Annual Energy Review 2006, Table 5.1, p. 125. See: 

http://www.eia.doe.gov/emeu/aer/pdf/pages/sec5_5.pdf
II-2 

• Greenhouse gas emissions from the consumption of petroleum have become a subject of 

increasing public policy concern, both in the United States and internationally. 

Greenhouse gases in general and carbon dioxide in particular have not thus far been 

subject to national regulation. Studies by multiple sources suggest that rising 

atmospheric concentrations of greenhouse gases will damage human health and welfare.13 

There is a direct linkage between the consumption of fossil energy and emissions of the 

greenhouse gas carbon dioxide, as essentially all of the carbon in hydrocarbon fuels is 

oxidized into carbon dioxide when the fuel is combusted. Reducing U.S. fossil energy 

consumption will generally induce a proportional reduction in carbon dioxide emissions. 

Energy is an essential input to the U.S. economy, and having a strong economy is essential to 

maintaining and strengthening our national security. Secure, reliable, and affordable energy 

sources are fundamental to economic stability and development. Rising energy demand poses a 

challenge to energy security, given increased reliance on global energy markets. As noted 

above, U.S. energy consumption has increasingly been outstripping U.S. energy production. 

Table II-1 presents trend data on the production and consumption of petroleum. Domestic 

petroleum production has been decreasing over time, while imports of petroleum have been 

increasing to meet the rising U.S. demand for petroleum. 

Conserving energy, especially reducing the nation’s dependence on petroleum, benefits 

the U.S. in several ways. Improving energy efficiency has benefits for economic growth 

and the environment, as well as other benefits, such as reducing pollution and improving 

security of energy supply. More specifically, reducing total petroleum use decreases our 

economy’s vulnerability to oil price shocks. Reducing dependence on oil imports from 

regions with uncertain conditions enhances our energy security and can reduce the flow 

of oil profits to certain states now hostile to the U.S. 

This reformed CAFE proposal would encourage broader use of fuel saving technologies, 

resulting in more fuel-efficient vehicles and greater overall fuel economy. 

 

13 IPCC 2007: Climate Change 2007: Synthesis Report: Contributions of Working Groups I, II, and III to the 

Fourth Assessment Report of the Intergovernmental Panel on Climate Change, [Core writing team, Pachauri, R.K. 

and Reisinger, A. 9eds.)] (Published by the Intergovernmental Panel on Climate Change, 2008). Available at 

http://www.ipcc.ch/, .
II-3 

Table II-1 

Petroleum Production and Supply 

(millions of barrels per day) 

 Domestic 

Petroleum 

Production 

Net 

Petroleum 

Imports 

U.S. 

Petroleum 

Supply 

World 

Petroleum 

Consumption 

Import Share 

of U.S. 

Supply 

1975 10.01 5.85 15.86 56.20 36.9% 

1985 10.58 4.29 14.87 60.09 28.9% 

1995 8.32 7.89 16.21 68.91 48.7% 

2005 6.89 12.55 19.44 83.00 64.6% 

DOE 

Predictions 

 

2015 5.91 12.52 18.43 67.9% 

2025 5.58 14.87 20.45 72.7% 

2030 5.39 16.37 21.76 75.2% 

“Petroleum Production and Consumption and Some Important Percent Shares, 1950-2006”, 

Transportation Energy Data Book: Edition 26 (2007), Table 1.12. 

http://cta.ornl.gov/data/Index.shtml

“Comparison of petroleum projections, 2015, 2025, and 2030”, Department of Energy, Energy 

Information Administration, Annual Energy Outlook 2007, Table 23. 

http://www.eia.doe.gov/emeu/aer/contents.html

Table II-2 

Transportation Consumption by Mode 

(millions of gallons per year) 

 

Passenger 

Cars 

Light 

Trucks 

Total Light 

Vehicles 

Total 

Transportation 

Light 

Vehicles as % 

of Trans. 

1975 74 19 93 139 67% 

1985 72 27 99 157 63% 

1995 68 46 114 188 61% 

2005 74 65 139 219 63% 

“Automobile Fuel Use and Fuel Type Shares for Calculation of Energy Use”, Transportation Energy Data Book: 

Edition 26 (2007) Table A.1, (Page A-7, appendix) http://cta.ornl.gov/data/Index.shtml

“Light Truck Fuel Use and Fuel Type Shares for Calculation of Energy Use”, Transportation Energy Data Book: 

Edition 26 (2007) Table A.1, (Page A-7, appendix) http://cta.ornl.gov/data/Index.shtml

 
III-1 

III. REGULATORY ALTERNATIVES 

In developing the proposed standards, the agency considered the four statutory factors 

underlying maximum feasibility as defined in EPCA (technological feasibility, economic 

practicability, the effect of other standards of the Government on fuel economy, and the 

need of the nation to conserve energy) as well as other relevant considerations such as 

safety. NHTSA assessed what fuel saving technologies would be available, how 

effective they are, and how quickly they could be introduced. This assessment 

considered technological feasibility, economic practicability and associated energy 

conservation. We also considered other standards to the extent captured by EPCA14 and 

environmental and safety concerns. This information was factored into the computer 

model used by NHTSA for applying technologies to particular vehicle models. The 

agency then balanced the factors relevant to standard setting. NHTSA’s NEPA analysis, 

discussed in the preamble of the accompanying notice, also will inform NHTSA’s 

consideration of the proposed standards and reasonable alternatives in developing a final 

rule. 

In balancing these factors, NHTSA generally observes that the increasing application of 

technologies increases fuel economy and associated benefits, but it also increases costs. 

Initial applications of technologies provide far more fuel savings per dollar of 

expenditure than applications of remaining technologies, which provide less incremental 

fuel savings at greater cost and, with progressive additions of technologies, eventually far 

greater cost. At some stage, the increasing application of technologies is not justified. A 

significant question is what methodology and decisionmaking criteria are used in the 

balancing to determine when to cease adding technologies and thus arrive at regulatory 

fuel economy targets. 

In developing its proposed standards, the agency used a net benefit-maximizing analysis 

that placed monetary values on relevant externalities (both energy security and 

environmental externalities, including the benefits of reductions in CO2 emissions) and 

produced what is called the “optimized scenario.” The optimized standards reflect levels 

such that, considering the seven largest manufacturers, net benefits (that is, total benefits 

minus total costs) are higher than at every other examined level of stringency. The 

agency also reviewed the results of the model’s estimates of stringencies maximizing net 

benefits to assure that the results made sense in terms of balancing EPCA’s statutory 

factors and in meeting EISA’s requirements for improved fuel economy. 

In addition to the optimized scenario, NHTSA considered and analyzed five additional 

regulatory alternatives that do not rely upon marginal benefit-cost analysis. In ascending 

order of stringency, the six alternatives are: 

•Standards that fall below the optimized scenario by the same absolute amount by 

which the +25 percent alternative exceeds the optimized scenario (“25 percent below 

optimized” alternative), 

 

14 71 Fed. Reg. 17566, 17669-70; April 6, 2006. 
III-2 

•Standards based on applying technologies until net benefits are maximized 

(optimized scenario), and 

•Standards that exceed the optimized scenario by 25 percent of the interval 

between the optimized scenario and the TC=TB alternative (see below) (“25 percent 

above optimized” alternative), 

•Standards that exceed the optimized scenario by 50 percent of the interval 

between the optimized scenario and the TC=TB alternative (“50 percent above 

optimized” alternative), 

•Standards based on applying technologies until total costs equal total benefits, 

i.e, until there are zero net benefits (TC=TB alternative),15 and 

•Standards based on applying all feasible technologies without regard to cost 

(technology exhaustion alternative).16

NHTSA chose these alternatives in order to consider and evaluate the impacts of 

balancing the EPCA factors differently in determining maximum feasibility than the 

agency has in prior rulemakings. In Center for Biological Diversity v. NHTSA, the Ninth 

Circuit Court recognized that “EPCA gives NHTSA discretion to decide how to balance 

the statutory factors—as long as NHTSA’s balancing does not undermine the 

fundamental purpose of EPCA: energy conservation.” 508 F.3d 508, 527 (9th Cir. 2007). 

The Court also raised the possibility that NHTSA’s current balancing of the statutory 

factors might be different from the agency’s balancing in the past, given the greater 

importance today of the need of the nation to conserve energy and more advanced 

understanding of climate change. Id. at 530-31. 

NHTSA recognizes that numerous alternative CAFE levels are theoretically conceivable 

and that the alternatives described above essentially represent only several on a 

continuum of alternatives. Along the continuum, each alternative represents a different 

way in which NHTSA conceivably could assign weight to each of the four EPCA factors 

and NEPA’s policies. For the alternatives that fall above the optimized scenario (the +25, 

+50 and TC=TB alternatives), the agency would evaluate policies that put increasingly 

more emphasis on reducing energy consumption and CO2 emissions, given their impact 

on global warming, and less on the other factors, including the economic impacts on the 

industry. Conversely, for the alternative that falls below the optimum scenario, the 

agency would evaluate policies that place relatively more weight on the economic health 

of the industry and less on reducing energy consumption and CO2 emissions. 

 

15 The agency considered the “TC=TB” alternative because one or more commenters in the rulemaking on 

standards for MY 2008-2011 light trucks urged NHTSA to consider setting the standards on this basis 

rather than on the basis of maximizing net benefits. In addition, while the Ninth Circuit Court of Appeals 

concluded that EPCA neither requires nor prohibits the setting of standards at the level at which net 

benefits are maximized, the Court raised concerns about tilting the balance more toward reducing energy 

consumption and CO2. 16 This was accomplished by determining the stringency at which a reformed standard would require every 

manufacturer to apply every technology estimated to be potentially available. At such stringencies, all but 

one manufacturer would be expected to fail to comply with the standard, and many manufacturers would 

owe large civil penalties as a result. The agency considered this alternative because the agency wished to 

explore the stringency and consequences of standards based solely on the potential availability of 

technologies at the individual manufacturer level. 
III-3 

For reasons such as those set forth in this section, NHTSA’s provisional analysis of the 

alternatives described above suggests that some of them may not satisfy the four EPCA 

factors that NHTSA must apply in setting “maximum feasible” CAFE standards. 

NHTSA seeks comments on the proposed standards and the regulatory alternatives to aid 

the agency’s determination of what standards to adopt in the final rule. 

The graphs below show, for passenger cars, light trucks, and the combined fleet, the 

average annual fuel economy levels for the four alternatives as compared to the proposed 

standards. Subsequent graphs and tables present their estimated costs, benefits, and net 

benefits (in billions of dollars). In addition, tables are provided summarizing the average 

extent to which manufacturers’ CAFE levels are projected to fall short of CAFE 

standards—i.e., the average shortfall—under each of these alternatives. Manufacturerspecific shortfall is shown for the proposed and TC=TB alternative. 
III-4 

Figure III-1. Average Required CAFE Levels (mpg) for Passenger Cars under 

Proposed and Alternative Standards 

 

50454035302520

2011 2012 2013 2014 2015

Model Year

Average Required CAFE Level (mpg) 25% Below Proposed

Proposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-5 

Figure III-2. Average Required CAFE Levels (mpg) for Light Trucks under 

Proposed and Alternative Standards 

 

50454035302520

2011 2012 2013 2014 2015

Model Year

Average Required CAFE Level (mpg)

25% Below ProposedProposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-6 

Figure III-3. Average Required CAFE Levels (mpg) for Overall Fleet under 

Proposed and Alternative Standards 

 

50454035302520

2011 2012 2013 2014 2015

Model Year

Average Required CAFE Level (mpg)

25% Below ProposedProposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-7 

Figure III-4. Total Benefits under Proposed and Alternative Standards 

 

0

5,000

45,00040,00035,00030,00025,00020,00015,00010,000

2011 2012 2013 2014 2015

Model Year

Total Benefits ($m)

25% Below ProposedProposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-8 

Figure III-5. Total Costs under Proposed and Alternative Standards 

 

0

5,000

45,00040,00035,00030,00025,00020,00015,00010,000

2011 2012 2013 2014 2015

Model Year

Total Costs ($m)

25% Below ProposedProposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-9 

Figure III-6. Net Benefits under Proposed and Alternative Standards 

 For the proposal and each regulatory alternative, the Tables 22 and 23 show the total net 

benefits in millions of dollars at a 7 percent discount rate for the projected fleet of sales 

for each model year. 

0

5,000

45,00040,00035,00030,00025,00020,00015,00010,000

2011 2012 2013 2014 2015

Model Year

Net Benefits ($m)

25% Below ProposedProposed (Maximum Net Benefit)25% Above Proposed50% Above ProposedTotal Costs Equal to Total BenefitsMaximum Technology
III-10 

 Table III-1 

Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

(Millions of 2006 Dollars) 

(Discounted 7%) 

 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Passenger Cars 

25% Below 1,156 2,104 3,235 5,197 6,799 

Optimized 2,596 4,933 6,148 7,889 9,420 

25% Above 3,755 7,280 8,454 10,638 12,083 

50% Above 4,274 8,825 10,213 12,576 14,495 

TC = TB 5,769 10,878 12,087 14,644 16,492 

Technology 

Exhaustion 

 5,834 11,282 12,968 15,930 18,061 

 

Light Trucks 

25% Below 3,508 7,910 12,603 12,433 12,441 

Optimized 3,909 8,779 13,560 14,915 16,192 

25% Above 4,201 9,990 14,236 16,587 19,457 

50% Above 4,642 10,507 15,011 17,687 20,892 

TC = TB 5,027 11,453 16,330 19,515 22,367 

Technology 

Exhaustion 

 5,088 11,457 19,418 22,093 24,779 

 

Combined PC+LT 

25% Below 4,664 10,014 15,838 17,630 19,240 

Optimized 6,505 13,712 19,708 22,804 25,612 

25% Above 7,956 17,270 22,690 27,225 31,540 

50% Above 8,916 19,331 25,224 30,263 35,387 

TC = TB 10,796 22,331 28,417 34,159 38,860 

Technology 

Exhaustion 

 10,922 22,795 32,363 38,004 42,820 
III-11 

 

Table III-2 

Total Costs 

(Millions of 2006 Dollars) 

(Discounted 7%) 

 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Passenger Cars 

25% Below 835 818 1,253 2,153 3,209 

Optimized 1,884 2,373 2,879 3,798 4,862 

25% Above 3,387 5,653 6,445 8,240 9,084 

50% Above 4,010 7,885 8,986 11,207 12,981 

TC = TB 5,913 10,796 12,303 15,403 17,398 

Max Technology 6,079 12,595 14,701 18,759 21,110 

 

Light Trucks 

25% Below 1,349 4,296 6,329 6,212 6,326 

Optimized 1,649 4,986 7,394 8,160 8,761 

25% Above 2,072 7,034 9,815 11,903 14,781 

50% Above 2,922 8,098 11,586 14,386 17,969 

TC = TB 3,788 10,525 15,196 18,762 21,364 

Max Technology 3,933 10,670 18,275 21,051 23,479 

 

Combined PC+LT 

25% Below 2,184 5,114 7,582 8,365 9,534 

Optimized 3,534 7,358 10,273 11,957 13,623 

25% Above 5,459 12,687 16,261 20,143 23,865 

50% Above 6,932 15,983 20,572 25,593 30,950 

TC = TB 9,702 21,321 27,499 34,164 38,761 

Max Technology 10,013 23,266 32,976 39,810 44,589 
III-12 

 

Table III-3 

Net Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

(Millions of 2006 Dollars) 

(Discounted 7%) 

 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Passenger Cars 

25% Below 321 1,285 1,982 3,045 3,590 

Optimized 711 2,560 3,269 4,092 4,558 

25% Above 368 1,627 2,009 2,398 2,999 

50% Above 264 940 1,226 1,370 1,514 

TC = TB -144 82 -216 -759 -906 

Max Technology -245 -1,313 -1,733 -2,829 -3,049 

 

Light Trucks 

25% Below 2,154 3,633 6,348 6,288 6,258 

Optimized 2,260 3,793 6,167 6,755 7,432 

25% Above 2,129 2,956 4,421 4,684 4,676 

50% Above 1,720 2,408 3,426 3,301 2,924 

TC = TB 1,239 928 1,134 753 1,004 

Max Technology 1,155 843 1,120 1,023 1,280 

 

Combined PC+LT 

25% Below 2,476 4,919 8,330 9,333 9,848 

Optimized 2,971 6,353 9,435 10,847 11,989 

25% Above 2,497 4,583 6,430 7,082 7,675 

50% Above 1,984 3,349 4,652 4,670 4,437 

TC = TB 1,094 1,010 918 -5 98 

Max Technology 909 -471 -613 -1,806 -1,769 

Negative values mean that costs exceed benefits. 

In tentatively deciding which alternative to propose, the agency looked at a variety of 

factors. The agency notes that once stringency levels exceed the point at which net 

benefits are maximized, the societal costs of each incremental increase in stringency 

exceed the accompanying societal benefits. If we have valued benefits appropriately, it 

does not make economic sense to mandate the spending of more money than society 

receives in return. The resources used to meet overly stringent CAFE standards, instead 
III-13 

of the optimized scenario standards, would better be allocated to other uses such as 

technology research and development, or improvements in vehicle safety. 

The agency considered the burden placed on specific manufacturers, consumers and 

employment. As CAFE standards increase, the incremental benefits are approximately 

constant while the incremental costs increase rapidly. Figure III-5 above shows that as 

stringency is increased, costs rise out of proportion compared to the benefits or the fuel 

savings. Increasingly higher costs have a negative impact on sales and employment. 

Each of the alternatives that is more stringent than the optimized alternative negatively 

impact sales and employment. 

The agency also considered technological feasibility. The Volpe model assumes that 

major manufacturers will exhaust all available technology before paying noncompliance 

civil penalties, even though the latter is often less costly. Historically, the large 

manufacturers have never paid civil penalties. NHTSA believes that there is a stigma to 

paying penalties that goes beyond economics. In the more stringent alternatives, the 

Volpe model predicts that increasing numbers of manufacturers will run out of 

technology to apply and, theoretically, resort to penalty payment. Setting standards this 

high is not technologically feasible, nor does it serve the need of the nation to conserve 

fuel. Paying a CAFE penalty does not result in any fuel savings. 

In analyzing the “-25 percent below optimized” alternative, the agency notes that these 

standards are more aggressive than the standards that the agency has proposed since the 

first years of the program and would impose unprecedented costs on manufacturers. The 

agency also recognizes that even this pace of increase in the standards may burden some 

of the manufacturers, particularly since the agency is now increasing car and light truck 

standards simultaneously. However, in light of the need of the nation to conserve energy 

and reduce global warming, the agency does not believe that this alternative would be 

maximum feasible under the statute. The agency is also concerned that the combined 

fleet might not reach the 35 mpg requirement by 2020 under EISA. 

Underlying the differences in costs, benefits, and net benefits for the other alternatives 

are differences in the degree to which NHTSA has estimated that technologies might be 

applied in response to the standards corresponding to each of these alternatives. The 

following tables show estimates of the average penetration rates of some selected 

technologies in the MY2015 passenger car and light truck fleets under each of the 

alternatives discussed here: 
III-14 

Table III-4 

Estimated Average Technology Penetration (Largest Seven Manufacturers) 

MY2015 Passenger Cars 

Technology

Product 

Plan

Adjusted 

Baseline

25% 

Below 

Proposed

Proposed 

Standard

25% 

Above 

Proposed

50% 

Above 

Proposed TC = TB

Tech. 

Exhaustion

Automatically Shifted Manual Transmissions 10% 10% 23% 39% 47% 55% 63% 69%

Spark Ignited Direct Injection Engines 22% 22% 22% 30% 37% 48% 68% 63%

Turbocharging & Engine Downsizing 5% 5% 8% 17% 30% 40% 62% 57%

Diesel Engines 0% 0% 3% 2% 7% 13% 18% 21%

Hybrid Electric Vehicles 5% 5% 14% 15% 22% 28% 35% 38%

Average Among Seven Largest Manufacturers

Table III-5 

Estimated Average Technology Penetration (Largest Seven Manufacturers) 

MY2015 Light Trucks 

Technology

Product 

Plan

Adjusted 

Baseline

25% 

Below 

Proposed

Proposed 

Standard

25% 

Above 

Proposed

50% 

Above 

Proposed TC = TB

Tech. 

Exhaustion

Automatically Shifted Manual Transmissions 10% 14% 42% 55% 58% 60% 59% 70%

Spark Ignited Direct Injection Engines 23% 24% 31% 40% 42% 55% 60% 69%

Turbocharging & Engine Downsizing 9% 11% 21% 31% 38% 51% 54% 65%

Diesel Engines 3% 6% 8% 10% 20% 23% 26% 28%

Hybrid Electric Vehicles 2% 6% 15% 25% 29% 31% 30% 30%

Average Among Seven Largest Manufacturers

As the first of the above tables indicates, the Volpe model estimated that, under the 

standards proposed today, manufacturers might triple the planned utilization of 

turbochargers and hybrid electric powertrains in the passenger car fleet. This table also 

indicates that the use of turbochargers in passenger cars might increase by an additional 

factor of two under the “25% above proposed” alternative. 

Similarly, the second table indicates that manufacturers might triple the planned 

utilization of diesel engines in the light truck fleet, and increase the utilization of hybrid 

electric powertrains by more than an order of magnitude. This table also shows a 

significant difference between the proposed and “25% above proposed” alternative, 

including an additional doubling in the utilization of diesel engines. 

NHTSA has examined the extent to which each alternative would (as estimated by the 

Volpe model and using the input information discussed in preceding sections) cause 

manufacturers to exhaust technologies projected to be available during MY2011-

MY2015. The following chart summarizes the frequency with which this was estimated 

to occur —i.e., the number of instances in which an individual manufacturer exhausted 

technologies and thus fell below a standard in individual model years divided by 35 

(seven manufacturers times five model years. 
III-15 

Figure III-6 

Calculated Prevalence of Technology Exhaustion 

As this analysis indicates, the “25% below proposed” alternative caused technologies to 

be exhausted 3% of the time for passenger cars, and 17% of the time for light trucks. 

Under the proposed standards, the rate of technology exhaustion increased to 11% for 

passenger cars, but did not change for light trucks. However, under the “25% above 

proposed” alternative, the corresponding rates increased to 26% and 37%, respectively. 

In other words, under this alternative, the Volpe model estimated that, more than a 

quarter of the time, manufacturers would be unable to comply with the passenger car 

standards solely using technologies expected to be available, and that they would be 0% 90% 80% 70% 60% 50% 40% 30% 20% 10% 100% 25% Below Proposed 25% Above 50% Above Total Cost = Total Benefit Technology Exhaustion Alternative

Calculated Prevalance of Technology Exhaustion

CarsTrucks
III-16 

unable to comply with the light truck standards using available technologies more than a 

third of the time. These rates were estimated to be considerably higher for the remaining 

three alternatives. 

These estimates of technology utilization and the exhaustion of available technologies 

indicate that all of the alternatives NHTSA has considered entail risk that one or more 

manufacturers would not be able comply with both the passenger car and light truck 

standards in every model year solely by applying technology. This risk is mitigated 

somewhat by the fact that our analysis may not encompass every technology that will 

potentially be available during MY2011-MY2015. For example, some manufacturers 

have made public statements regarding hopes to offer “plug-in” HEVs before MY2015, 

but such vehicles are not represented in our analysis.17 Nonetheless, the agency has 

tentatively concluded that the scope of technologies it has included is comprehensive 

enough that the analysis shown above indicates that under some alternatives, there is 

considerable risk that some manufacturers would exhaust available technologies in some 

model years. 

In tentatively concluding that the proposed standards are the maximum feasible 

standards, NHTSA has balanced this risk against the other considerations it must take 

into account, in particular the need of the nation to conserve energy, which encompasses 

concerns regarding carbon dioxide emissions. The agency’s analysis includes economic 

measures of these needs—that is, economic measures of the externalities of petroleum 

consumption and the damages associated with carbon dioxide emissions. These measures 

are reflected in the agency’s estimates of the total and net benefits of each of the 

alternatives. 

NHTSA is proposing standards that it estimates will entail risk that some manufacturers 

will exhaust available technologies in some model years. However, relative to the less 

stringent “25% below proposed” alternative, the agency has tentatively concluded that the 

additional risk is outweighed by the significant increase in estimated net benefits to 

society, ranging from an additional $0.5b in MY2011 to an additional $2.1b in MY2015. 

Conversely, the agency has tentatively concluded that, relative to the proposed standards, 

the more than doubling of risk posed by the “25% above proposed” alternative is not 

warranted, especially considering that this alternative is estimated to significantly reduce

net benefits, by $0.5b in MY2011 and, eventually, $4.3b in MY2015. 

The agency invites comment regarding whether it has struck a proper balance and, if not, 

how it should do so. The alternatives identified by the agency are intended to aid public 

commenters in helping the agency to explore that issue. 

 

Notwithstanding the tentative conclusions described above, NHTSA seeks comment on 

these regulatory alternatives to aid in determining what standards to adopt in the final 

rule. Specific sensitivity runs that vary fuel prices, the rebound effect, CO2 and discount 

rate were conducted for the proposed optimized standards. These analyses have an 

 

17 If included in the new product plans that the agency is requesting, these vehicles will be included in our 

analysis for the final rule. 
III-17 

impact on the standards, costs and benefits. For example, in analyzing the “optimized 

alternative”, we estimated that following the same methods and criteria for setting the 

standards, but applying a 3% discount rate rather than a 7% discount rate, would suggest 

standards reaching about 33.6 mpg (average required fuel economy among both 

passenger cars and light trucks) in MY2015, 2 mpg higher than the 31.6 mpg average 

resulting from the standards we are proposing based on a 7% discount rate. The more 

stringent standards during MY2011-MY2015 would reduce CO2 emissions by 672 

million metric tons (mmt), or 29% more than the 521 mmt achieved by the proposed 

standards. On the other hand, we estimate that standards increasing at this pace would 

require about $85b in technology outlays during MY2011-MY2015, or 89% more than 

the $45b in technology outlays associated with the standards proposed today. The impact 

of the 3% rate is shown in the body of the PRIA along with the 6 formal alternatives. All 

other sensitivity analyses are shown in Chapter IX. 
IV-1 

IV. IMPACT OF OTHER FEDERAL MOTOR VEHICLE STANDARDS ON 

 FUEL ECONOMY 

Introduction 

The Energy Policy and Conservation (EPCA or the Act) requires that fuel economy 

standards be set at the maximum feasible level after taking into account the following 

criteria: (1) technological feasibility, (2) economic practicability, (3) the impact of other 

Federal Motor Vehicle Standards on fuel economy, and (4) the need of the Nation to 

conserve energy. This section discusses the effects of other government regulations on 

model year (MY) 2011-2015 passenger car and light truck fuel economy. 

The Impact of Safety Standards and Voluntary Safety Improvements 

The fuel economy impact of safety improvements will typically take the form of 

increased vehicle weight, which reduces the fuel economy of the vehicle. The 

manufacturer’s estimates of weight and fuel economy impact have already been included 

in their baseline fuel economy projections. In some instances the manufacturers’ weight 

estimates are similar to NHTSA’s, in some instances they are less than NHTSA’s, but 

often they are more than NHTSA’s. The agency’s estimates are based on cost and weight 

tear-down studies of a few vehicles and cannot possibly cover all the variations in the 

manufacturers’ fleets. NHTSA requested and various manufacturers provided estimates 

of increases in weight resulting from safety improvements, based on a MY 2007 baseline. 

However, for the passenger car and light truck proposal MY 2010 is the baseline. Thus, 

only safety equipment required to be installed or voluntarily installed after these dates are 

included in this analysis. 

We have broken down our analysis of the impact of safety standards that might affect the 

MY 2011-2015 fleets into two parts, those final rules with known effective dates, and 

proposed rules without final effective dates or currently voluntary safety improvements. 

Weight Impacts of Required Safety Standards (Final Rules) 

The National Highway Traffic Safety Administration (NHTSA) has issued two final rules 

on safety standards that become effective for passenger cars and light trucks between MY 

2011 and MY 2015. These have been analyzed for their potential impact on passenger 

car and light truck weights, using MY 2010 as a baseline. 

1. FMVSS 126, Electronic Stability Control 

2. FMVSS 214, Side Impact Oblique Pole Test 

FMVSS 126, Electronic Stability Control

The phase-in schedule for vehicle manufacturers is: 

Model Year Production Beginning Date Requirement 

2009 September 1, 2008 55% with carryover credit 

2010 September 1, 2009 75% with carryover credit 

2011 September 1, 2010 95% with carryover credit 

2012 September 1, 2011 All light vehicles 
IV-2 

The final rule requires 75 percent of all light vehicles to meet the ESC requirement for 

MY 2010, 95 percent of all light vehicles to meet the ESC requirements by MY 2011, 

and all light vehicles must meet the requirements by MY 2012. 

The agency’s analysis of weight impacts found that ABS adds 10.7 lbs. and ESC adds 1.8 

lbs. per vehicle for a total of 12.5 lbs. Based on manufacturers’ plans for voluntary 

installation of ESC, 85 percent of passenger cars in MY 2010 would have ABS and 52 

percent would have ESC. Thus, the total incremental added weight over manufacturers’ 

plans in MY 2011 for passenger cars would be about 1.8 lbs. (0.10*10.7 + 0.43*1.8) and 

in MY 2012 an incremental 0.6 lbs. (0.05*10.7 + 0.05*1.8). Light trucks manufacturers’ 

plans show that 99 percent of all light trucks would have ABS and that 74 percent would 

have ESC by MY 2010. Thus, for light trucks the incremental weight impacts of adding 

ESC would be 0.4 lbs. (0.21*1.8) in MY 2011 and an incremental 0.1 lbs. (0.01*10.7 + 

0.05*1.8) in MY 2012. 

FMVSS 214, Oblique Pole Side Impact Test

The phase-in requirements for the side impact test are as shown below in Table IV-118: 

Table IV-1 

FMVSS 214 Final Rule Phase-In Schedule 

Phase-in Date Percent of each manufacturer’s light vehicles that must comply 

during the production period 

September 1, 2009 to 

August 31, 2010 

20 percent (excluding vehicles GVWR > 8,500 lbs.) 

September 1, 2010 to 

August 31, 2011 

50 percent vehicles (excluding vehicles GVWR > 8,500 lbs.) 

September 1, 2011 to 

August 31, 2012 

75 percent vehicles (excluding vehicles GVWR > 8,500 lbs.) 

September 1, 2012 to 

August 31, 2013 

All vehicles including limited line vehicles, except vehicles with 

GVWR > 8,500 lbs., alterers, and multi-stage manufacturers 

On or after 

September 1, 2013 

All vehicles, including vehicles with GVWR > 8,500 lbs., alterers 

and multi-stage manufacturers 

 

Based on manufacturers’ plans to voluntarily provide window curtains and torso bags, we 

estimate that 90 percent of passenger cars and light trucks would have window curtains 

for MY 2010 and 72 percent would have torso bags. A very similar percentage is 

estimated for MY 2011. A teardown study of 5 thorax air bags resulted in an average 

weight increase per vehicle of 4.77 pounds (2.17 kg).19 A second study20 performed 

teardowns of 5 window curtain systems. One of the window curtain systems was very 

 

18 The agency has received several petitions for reconsideration to extend the lead time. 

19 Khadilkar, et al. “Teardown Cost Estimates of Automotive Equipment Manufactured to Comply with 

Motor Vehicle Standard – FMVSS 214(D) – Side Impact Protection, Side Air Bag Features”, April 2003, 

DOT HS 809 809. 

20 Ludtke & Associates, “Perform Cost and Weight Analysis, Head Protection Air Bag Systems, FMVSS 

201”, page 4-3 to 4-5, DOT HS 809 842. 
IV-3 

heavy (23.45 pounds). The other four window curtain systems had an average weight 

increase per vehicle of 6.78 pounds (3.08 kg), a figure which is assumed to be average for 

all vehicles in the future. 

Assuming in the future that the typical system used to comply with the requirements of 

FMVSS No. 214 will be thorax bags with a window curtain, the average weight increase 

would be 2 pounds (0.10*6.78 + 0.28*4.77) in MY 2013. However, there is the potential 

that some light trucks might need to add structure to meet the test. The agency has no 

estimate of this potential weight impact for structure. 

Weight Impacts of Proposed/Planned Safety Standards 

Proposed FMVSS 216, Roof Crush

On August 23, 2005, NHTSA proposed amending the roof crush standard to increase the 

roof crush standard from 1.5 times the vehicle weight to 2.5 times the vehicle weight21. 

The NPRM proposed to extend the standard to vehicles with a GVWR of 10,000 pounds 

or less, thus including many light trucks that had not been required to meet the standard 

in the past. The proposed effective date was the first September 1 occurring three years 

after publication of the final rule. In the PRIA, the average passenger car weight was 

estimated to increase by 4.0 pounds and the average light truck weight was estimated to 

increase by 6.1 pounds for a 2.5 strength to weight ratio. Based on comments to the 

NPRM, the agency believes that this weight estimate is likely to increase. However, the 

agency does not yet have an estimate for the final rule. 

 

Planned NHTSA initiative on Ejection Mitigation

The agency is planning on issuing a proposal on ejection mitigation. The likely result of 

the planned proposal is for window curtain side air bags to be larger and for a rollover 

sensor to be installed. The likely result will be an increase in weight of at least one 

pound, however, this analysis is not completed. In addition, advanced glazing is one 

alternative that manufacturers might pursue for specific window applications (possibly 

for fixed windows for third row applications) or more broadly. Advanced glazing is 

likely to have weight implications. Again the agency has not made an estimate of the 

likelihood that advanced glazing might be used or its weight implications. 

Possible NHTSA initiative on Pedestrian Protection

The agency has started to analyze the costs and benefits of a potential Global Technical 

Regulation on pedestrian protection. Whether the agency will propose a rulemaking and 

the effective dates have not been decided, however, it is possible that a rule on pedestrian 

protection could start to be phased in by the end of the period of this proposed 

rulemaking. Potential weight increases for pedestrian head and leg protection have not 

yet been identified. 

Summary – Overview of Anticipated Weight Increases 

 

21 See 70 FR 53753, the PRIA is in Docket No. 22143, entry #2 “Preliminary Regulatory Impact Analysis, 

FMVSS 216, Roof Crush Resistance,” August 2005. 
IV-4 

The following table summarizes estimates made by NHTSA regarding the weight added 

in MY 2011 or later to institute the above discussed standards or likely rulemakings. In 

summary, NHTSA estimates that weight additions required by final rules and likely 

NHTSA regulations effective in MY 2011 and beyond, compared to the MY 2010 fleet 

and manufacturers’ plans, will increase passenger car weight by at least 9.4 lbs. and light 

truck weight by at least 9.6 lbs. 

Table IV-2 

Weight Additions Due to Final Rules or Likely NHTSA Regulations 

Compared to MY 2010 Baseline fleet 

Standard No. 

Added 

Weight in 

pounds 

Passenger Car

Added 

Weight in 

kilograms 

Passenger 

Car

Added 

Weight in 

pounds 

Light 

Trucks

Added Weight 

in kilograms 

Light trucks

126 2.4 1.1 0.5 0.2 

214 2.0 0.9 2.0 - ? 0.9 - ? 

216 4.0 - ? 1.8 - ? 6.1 - ? 2.8 - ? 

Ejection 

Mitigation 

1.0 - ? 0.4 - ? 1.0 - ? 0.4 - ? 

Total 9.4 - ? 4.2 - ? 9.6 - ? 4.3 - ? 

Based on NHTSA’s weight-versus-fuel-economy algorithms, a 3-4 pound increase in 

weight equates to a loss of 0.01 mpg in fuel economy. Thus, the agency’s estimate of the 

safety/weight effects are 0.024 to 0.032 mpg or more for already issued or likely future 

safety standards. 

CONFIDENTIAL SUBMISSIONS 

Weight Impacts of Potential Future Voluntary Safety Improvements 

At the time the agency requested information about fuel economy plans and capabilities 

for the future, the agency also requested information on weight increases that could occur 

due to safety improvements. Several manufacturers provided confidential information 

about plans they had to meet final rules, proposed safety standards, or to voluntarily 

increase safety. The baseline for these plans was MY 2007. Several of these plans were 

to meet IIHS offset frontal of side impact testing. Most of these improvements will be 

installed on vehicles by MY 2011. [ 

.] Thus, many of them will have occurred by the time this rulemaking is effective. The 

areas covered above and the remaining areas described as voluntary safety initiatives that 

have weight implications and the confidential weight estimates are shown in Table IV-3 

after MY 2007 and on Table IV-3a for those initiatives taking affect after MY 2011. 
IV-5 

[Table IV-3 

Confidential Submissions on Safety Standards and Voluntary Safety Improvements 

Any model year after MY 2007 

DCX Ford GM 

Pounds Kg. Pounds Kg. Pounds Kg. 

ESC 

Side Impact 

Roof Crush 

Vehicle 

Compatibility 

 

Ejection Mitigation 

Pedestrian 

Protection 

 

IIHS frontal pole 

test 

Lane Departure 

Warning 

 

Total all actions 

after MY 2007 

 

] 
IV-6 

[Table IV-3a 

Confidential Submissions of Weight Impacts After MY 2011 

DCX Ford GM 

Pounds Kg. Pounds Kg. Pounds Kg. 

ESC 

Side Impact 

Roof Crush 

Vehicle 

Compatibility 

 

Ejection Mitigation 

Pedestrian 

Protection 

 

Misc. structure for 

ratings 

IIHS frontal pole 

test 

Lane Departure 

Warning 

 

Total all actions 

after MY 2011 

 
IV-7 

Vehicle Size and Safety 

NHTSA believes that an attribute based Reformed CAFE system removes the incentive 

to downsize that is inherent in the traditional fleet-wide CAFE flat standard requirement. 

The agency believes that the attribute based standard is likely to have beneficial impacts 

on safety compared to the flat standard. Other things being equal, smaller vehicles 

provide less protection to their occupants in the event of a crash because there is less 

vehicle mass to absorb the crash energy and less interior space to buffer occupants from 

sheet metal intrusion. In addition, smaller vehicles are generally more likely to roll over. 

In single vehicle crashes, smaller vehicles are less safe than larger vehicles. In multivehicle crashes, both individual vehicle size and the relative size of the involved vehicles 

play a role in determining the injury outcome of occupants. Generally, larger vehicles 

will provide better protection, but often at the expense of occupants of smaller vehicles. 

If larger vehicles were to be reduced in size, it would likely decrease the chance of injury 

in crashes with smaller vehicles, but it would also likely increase the chance of injury for 

the occupants of the larger vehicles. The makeup of any future mix-shifts in vehicle sales 

is purely speculative and the overall impact on injuries in multi-vehicle crashes of any 

future mix-shifts in vehicle size is unknown. However, downsizing is likely to increase 

the crash risk for vehicle occupants in single vehicle crashes, which make up 30% of all 

crashes and 57% of all fatalities. An attribute based system will require improvements in 

fuel economy for all vehicle sizes, and will thus minimize incentives to downsize 

vehicles. 

 

 

The NAS study 

The 2002 National Academy of Sciences (NAS)22 report made explicit links between 

weight and vehicle safety. The NAS study conclusions were divided, with 11 of 13 

committee members representing the majority view and 2 of 13 the minority view. The 

findings of the majority presented on page 77 were: 

“In summary, the majority of the committee finds that the downsizing and weight 

reduction that occurred in the late 1970s and early 1980s most likely produced between 

1,300 and 2,600 crash fatalities and between 13,000 and 26,000 serious injuries in 1993. 

The proportion of these casualties attributable to CAFE standards is uncertain. It is not 

clear that significant weight reduction can be achieved in the future without some 

downsizing, and similar downsizing would be expected to produce similar results. Even 

if weight reduction occurred without any downsizing, casualties would be expected to 

increase. Thus, any increase in CAFE as currently structured could produce additional 

road casualties, unless it is specifically targeted at the largest, heaviest light trucks.” ... 

“Some might argue that this improving safety picture means that there is room to improve 

fuel economy without adverse safety consequences. However, such a measure would not 

achieve the goal of avoiding the adverse safety consequences of fuel economy increases. 

Rather, the safety penalty imposed by increased fuel economy (if weight reduction is one 

of the measures) will be more difficult to identify in the light of the continuing 

improvement in traffic safety. Just because these anticipated safety innovations will 

 

22 “Effectiveness and Impact of Corporate Average Fuel Economy (CAFE) Standards”, National 

Research Council, 2002. The link for the NAS report is http://www.nap.edu/books/0309076013/html/
IV-8 

improve the safety of vehicles of all sizes does not mean that downsizing to achieve fuel 

economy improvements will have no safety costs. 

If an increase in fuel economy is effected by a system that encourages either 

downweighting or the production and sale of more small cars, some additional traffic 

fatalities would be expected. Without a thoughtful restructuring of the program, that 

would be the trade-off that must be made if CAFE standards are increased by any 

significant amount.” 

The minority view summarized on page 123 was: 

 “The relationship between vehicle weight and safety are complex and not 

measurable with any reasonable degree of certainty at present. The relationship of fuel 

economy to safety is even more tenuous. But this does not mean that there is no reason 

for concern. Significant fuel economy improvements will require major changes in 

vehicle design. Safety is always an issue whenever vehicles must be redesigned. 

 In addition, the distribution of vehicle weights is an important safety issue. Safety 

benefits should be possible if the weight distribution of light-duty vehicles could be made 

more uniform, and economic gains might result from even partly correcting the negative 

externality that encourages individuals to transfer safety risks to others by buying ever 

larger and heavier vehicles. 

 Finally, it appears that in certain kinds of accidents, reducing weight will increase 

safety risk, while in others it may reduce it. Reducing the weights of light-duty vehicles 

will neither benefit nor harm all highway users, there will be winners and losers....” 

The Kahane Study 

The Kahane study23 estimates the effect of 100-pound reductions in heavy light trucks 

and vans (LTVs), light LTVs, heavy passenger cars, and light passenger cars. It 

compares the fatality rates of LTVs and cars to quantify differences between vehicle 

types, given drivers of the same age/gender, etc. Some of its findings are: 

 “Heavy vehicles had lower fatality rates per billion miles of travel than lighter 

vehicles of the same general type. When two vehicles collide, the laws of physics favor 

the occupants on the heavier vehicle (momentum conservation). Furthermore, heavy 

vehicles were in most cases, longer, wider and less fragile than light vehicles. In part 

because of this, they usually had greater crashworthiness, structural integrity and 

directional stability. They were less rollover-prone and easier for the average driver to 

control in a panic situation. In other words, heavier vehicles tended to be more 

crashworthy and less crash-prone. Some of the advantages for heavier vehicles are not 

preordained by the laws of physics, but were nevertheless characteristic of the MY 9991-

99 fleet. Offsetting those advantages, heavier vehicles tended to be more aggressive in 

crashes, increasing risk to occupants of the vehicles they collide with.” 

Six different crash modes were analyzed (principal rollover, fixed object, 

pedestrian/bicycle/motorcyclist, and multi-vehicle crashes with heavy truck, light trucks, 

 

23 “Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 Passenger Cars and 

Light Trucks”, Charles J. Kahane, Ph. D., NHTSA, October 2003, DOT HS 809-662. 
IV-9 

and passenger cars). Summing all these crash modes together, the net annual effects per 

100-pound weight reduction were: 

For passenger cars weighing less than 2,950 pounds – fatalities increased by 597 

For passenger cars weighing 2,950 pounds or more – fatalities increased by 216 

For light trucks weighing less than 3,870 pounds – fatalities increased by 234 

For light trucks weighing 3,870 pounds or more – fatalities increased by 71 

In all cases, annual fatalities increased with a reduction in weight. However, further 

analysis of the Kahane study found that the net safety effect of removing 100 pounds 

from a light truck is zero for the group of all light trucks with a curb weight greater than 

3,900 lbs. 24 Given the significant statistical uncertainty around that figure, we assumed a 

confidence bound of approximately 1,000 lbs. and used 5,000 lbs. as the threshold for 

considering weight reduction of specific models. In the MY 2008-2011 light truck final 

rule, NHTSA included weight reduction as a fuel improving technology for light trucks 

over 5,000 lbs. curb weight where we determined that weight reduction would not reduce 

overall safety and would be a cost-effective choice. We are applying the same 

methodology in this proposal, weight reduction is considered a technology that can be 

applied to light trucks over 5,000 lbs. curb weight. 

The agency believes a number of conclusions can be drawn from these studies: 

• Heavier vehicles are more crashworthy and less crash prone.25 

• The net impacts on safety, considering the six different crash modes, of reducing 

weight are negative for all but the larger light trucks. However, this type of 

analysis can not examine extreme cases. For example, if there were a large mix 

shift from 50 percent passenger car and 50 percent light truck sales, to 80 percent 

compact or smaller passenger cars and 20 percent pickup truck sales, this analysis 

cannot determine the net impacts on safety. Nothing in the manufacturer’s plans 

suggests a drastic change in the mix of vehicles, nor is there any incentive, in our 

opinion, for such a change based on NHTSA’s attribute based proposal on fuel 

economy. 

• Lighter vehicles fare worse in single vehicle collisions. In 2006, 57 percent of all 

passenger car and light truck fatalities were in single vehicle crashes and 43 

percent were in multi-vehicle crashes. Fatalities are almost split between 

rollovers (29 percent) and fixed or non-fixed objects (28 percent). 

• Reducing weight increases the likelihood of rolling over. When you are sliding 

sideways and digging into mud or grass or hit a curb, all things being equal, the 

lighter vehicle is more prone to rolling over. Increasing track width (part of the 

footprint calculation) reduces the likelihood of rolling over. Track width is more 

important than weight for rollovers. Rollover is the only area in which track 

 

24Kahane, Charles J., PhD, Vehicle Weight, Fatality Risk and Crash Compatibility of Model Year 1991-99 

Passenger Cars and Light Trucks, October 2003. DOT HS 809 662. Page 161. Docket No. NHTSA-2003-

16318 (http://www.nhtsa.dot.gov/cars/rules/regrev/evaluate/pdf/809662.pdf) 25 See Kahane study, page xiv Table 3 for prorated fatal crash involvements per billion miles. 
IV-10 

width is the most important factor. Weight is more important than track width or 

wheelbase in the other five crash modes investigated.26 

• Reducing weight increases the likelihood of being killed in a fixed or non-fixed 

object crash. If you run into a tree, you are safer if you knock that tree down than 

if the tree stops your vehicle. A heavier vehicle has a better chance of knocking 

the tree down. 

The Kahane report also examined the total fatality crash rates in all crash modes; 

including fatalities to occupants of the case vehicle (i.e. in rollovers, single vehicle and 

multi-vehicle crashes), occupants of the other vehicle it collided with (to account for 

aggressive vehicles) and pedestrians. Kahane used VMT data based on CDS odometer 

readings and controlled for age and gender based on State data on nonculpable crash 

involvements (induced exposure). With these controls, the societal fatality rates per 

billion miles were: 

TABLE IV-4 

ADJUSTED FATAL-CRASH INVOLVEMENT RATES 

PER BILLION CASE VEHICLE MILES, BY VEHICLE TYPE 

(Case vehicles are MY 1996-99 light trucks and 4-door cars with air bags in CY 1996-

2000, adjusted for age/gender, rural/urban, day/night, speed limit, and other factors) 

 

 Average Fatal 

 Curb Crash Involvements 

Vehicle Type and Size Weight Per Billion Miles 

Very small 4-door cars 2,105 15.73 

Small 4-door cars 2,469 11.37 

Mid-size 4-door cars 3,061 9.46 

Large 4-door cars 3,596 7.12 

Compact pickup trucks 3,339 11.74 

Large (100-series) pickup trucks 4,458 9.56 

Small 4-door SUVs 3,147 10.47 

Mid-size 4-door SUVs 4,022 13.68 

Large 4-door SUVs 5,141 10.03 

Minivans 3,942 7.97 

In other words, mid-size cars had somewhat lower societal fatal crash rates than SUVs 

that weighed considerably more. Large cars and minivans had the lowest rates. 

 

26 See Kahane (Docket No. 2003-16318-16) 
IV-11 

Advocates for Highway and Auto Safety commented that Kahane’s (NHTSA’s) 2003 

analysis may not apply if the effects of size and weight reductions are disaggregated, 

“weight reductions without corresponding reductions in vehicle wheelbase length and 

track width could be expected to produce net benefits in reducing occupant crash risks.” 

NHTSA’s response is that Footprint (especially track width) is an important variable in 

terms of a vehicle’s propensity for rollovers, a type of crash that accounts for 29 percent 

of all light vehicle occupant traffic fatalities. Track width is one of the two vehicle 

properties that define Static Stability Factor (SSF). SSF was used as a single 

predominant factor to predict rollover rate in the agency’s original rollover NCAP, and it 

is still the most powerful element in the agency’s current rollover NCAP risk model that 

also factors in a road maneuver test. Wheelbase does not have a direct effect on rollover 

resistance. However, there are hypotheses that an increase in wheelbase could reduce 

loss-of-control crashes by making the vehicle react slower in yaw and thereby reduce the 

number of single-vehicle pavement departure crashes that produce most rollovers. 

Currently, the agency does not have any data to substantiate this theory.27 

We would like to clarify that our analysis does not mandate weight reduction, or any 

specific technology application for that matter. Our analysis relied exclusively on other 

fuel-saving technologies for passenger cars and only applied weight reduction to light 

trucks that have a curb weight greater than 5,000 lbs. to demonstrate that manufacturers 

can comply with the proposed fuel economy levels without the need for potentially 

unsafe compliance measures. 

Honda cited several reports, which it asserted demonstrated that limited weight 

reductions would not reduce safety and could possibly decrease overall fatalities. Honda 

stated that the 2003 study by DRI found that reducing weight without reducing size 

slightly decreased fatalities, and that this was confirmed in a 2004 study by DRI28 that 

assessed new data and methodology changes in the 2003 Kahane Study. Honda asserted 

that the DRI results tend to confirm “that curb weight reduction would be expected to 

decrease the overall number of fatalities.” 

DRI submitted an additional study, Supplemental Results on the Independent Effects of 

Curb Weight, Wheelbase, and Track Width on Fatality Risk in 1985-1998 Model Year 

Passenger Cars and 1985-1997 Model Year LTVs, Van Auken, R.M. and J. W. Zellner, 

May 20, 2005 (Docket No. 2003-16128-1456). This DRI study concluded that reductions 

in footprint are harmful to safety, whereas reductions in mass while holding footprint 

constant would benefit safety. The DRI study disagreed with NHTSA’s finding that mass 

had greater influence than track width or wheelbase on the fatality risk of passenger cars 

in non-rollover crashes. 

While NHTSA agrees that limited weight reduction to heavier vehicles will not reduce 

safety, we disagree with DRI’s overall conclusion, cited by Honda, that weight reductions 

 

27 See Kahane (Docket No. 2003-16318-16) 

28 See Docket Nos. 2003-16318-2, 2003-16318-3, and 2003-16318-7. 
IV-12 

while holding footprint constant would significantly benefit safety in lighter vehicles. 

NHTSA’s analyses of the relationships between fatality risk, mass, track width and 

wheelbase in 4-door 1991-1999 passenger cars (Docket No. 2003-16318-16) found a 

strong relationship between track width and the rollover fatality rate, but only a modest 

(although significant) relationship between track width and fatality rate in non-rollover 

crashes. Even controlling for track width and wheelbase – e.g., by holding footprint 

constant – weight reduction in the lighter cars is strongly, significantly associated with 

higher non-rollover fatality rates in the NHTSA analysis. By contrast, the DRI study of 

May 20, 2005 analyzed 4-door cars and found a strong relationship between track width 

and fatality risk, and non-significant associations of mass and wheelbase with fatality risk 

(Docket No. 2005-22223-78, p. 31). In other words, when DRI analyzed the same group 

of vehicles as NHTSA, they did not get the same results. This difference indicates that 

DRI’s analytical method and/or database are not the same as NHTSA’s. 

The agency continues to believe that weight reduction in lighter vehicles would reduce 

safety. However, we also believe that weight reductions in the heavier light trucks, while 

holding footprint constant, will not likely result in a net reduction in safety. In our 

opinion, it is impossible to reduce weight and maintain footprint unless you (a) substitute 

light for heavy materials in a big way or (b) remove features that customers want and are 

willing to pay for. In that sense, DRI’s contention that weight is unimportant could only 

be true for material substitution, because under present circumstance weight reduction 

usually also means size reduction, and DRI agrees with NHTSA that a reduction in 

footprint is harmful to safety. 

General Motors (Docket No. 2005-22223-1493) and the Alliance (Docket No. 2005-

22223-1642) were more explicit in their concerns over the safety impact associated with 

weight reduction. The Alliance stated that the fundamental laws of physics dictate that 

smaller and/or lighter vehicles are less safe than larger/heavier counterparts with 

equivalent safety designs and equipment. General Motors agreed that improvements in 

material strength, flexibility, and vehicle design have helped improve overall vehicle and 

highway safety. But, General Motors added, for a given vehicle, reducing mass generally 

reduces net safety. Further, General Motors stated that it does not intentionally reduce 

mass by replacing it with advanced materials, presuming that such action alone will result 

in improved protection for the occupants in a lighter vehicle; instead GM continues to 

believe that vehicles with larger mass will provide better protection to occupants involved 

in a crash than a vehicle of the same design with less mass, given equivalent crashes. 

General Motors also questioned the agency’s reliance on a 5,000 lbs. minimum vehicle 

weight for considering weight reduction, which was based on the finding of the 2003 

Kahane report. General Motors stated that the agency’s conclusion is inconsistent with 

the sensitivity analysis performed by William E. Wecker Associates, Inc.29 and submitted 

to the ANPRM docket. General Motors stated that the inflection point on the Wecker 

report’s graph for General Motors light trucks in both the periods of MYs 1991-1995 and 

MYs 1996-1999 is higher than 5,000 pounds. 

 

29 Docket No. 2003-16128-1112 
IV-13 

Additionally, General Motors stated that the NPRM did not acknowledge or respond to 

the main point of the Wecker report, which was that Dr. Kahane’s “analysis alone does 

not support the proposition that a crossover weight at or near 5,085 pounds is a robust, 

accurate description of the field performance of the fleet.” 

We believe that General Motors was confusing the 5,085 lbs. crossover weight (where 

the safety effect of mass reduction in a vehicle weighing exactly 5,085 lbs., is zero) with 

the breakeven point described in the NPRM, which is the point where the total effect of 

reducing all vehicles heavier than the breakeven weight by an equal amount is zero. 

NHTSA estimated that the breakeven point as described in the NPRM is 3,900 lbs., if 

footprint is held constant. 

If the 3,900 lbs. estimate were perfectly accurate, we would be confident that weight 

reductions in vehicles down to 3,900 pounds would not result in net harm to safety. 

However, we agree with commenters that there is considerable uncertainty about the 

crossover weight and also the breakeven point. Therefore, in our analysis, we limited 

weight reduction to vehicles with a curb weight greater than 5,000 pounds. We believe 

that the 5,000 lbs. limit is sufficient so that we can be confident that such weight 

reductions will not have net harm on safety. 

SUVOA encouraged NHTSA to emphasize the importance of making sure that CAFE 

requirements do not encourage vehicle downsizing “or any other action that might have 

an adverse effect on safety.” SUVOA cited several reports in support of its assertion that 

downsizing harms safety30. As explained above, the agency has applied weight reduction 

only to those vehicles for which we are confident that such reduction will not negatively 

impact safety, however, our analysis does not mandate the use of specific technologies or 

weight reductions. 

Environmental Defense (Docket No. 2005-22223-1805) commented that by limiting the 

use of weight reduction to heavier vehicles, the agency disregarded the likelihood that 

manufacturers would rely on weight reduction in smaller, lighter vehicles. 

Environmental Defense suggested that the improved baselines should reflect this weight 

reduction strategy. 

Environmental Defense asserted that weight reduction is among the most common and 

cost-effective options available to manufacturers for improving vehicle fuel economy 

 

30 SUVOA (see Docket No. 2003-16128-1067) provided the following cites in support of its assertion: 

• 2001, the National Academy of Sciences affirmed that earlier downsizing of vehicles following 

the imposition of CAFE regulations resulted in an additional 1,300 to 2,600 deaths and an 

additional 20,000 serious injuries per year. 

• A Harvard School of Public Health-Brookings Institution study in the 1990s found that vehicle 

downsizing due to federal fuel economy mandates increased occupant deaths by 14 to 27 percent. 

• An in-depth analysis by USA Today in 1999, using NHTSA and auto insurance industry data, 

found that since 1975, 7,700 additional deaths occurred for every mile per gallon gained. By 

1999, vehicle downsizing had killed more than 46,000 Americans. Factoring in the ensuing six 

years through 2005, the total conservatively eclipses 55,000 deaths. 
IV-14 

across the light truck fleet. Environmental Defense referenced estimates presented in 

DeCicco (2005) that suggest that the cost per pound of weight reduced through use of 

high-strength steel and advanced engineering techniques has been as low as, or lower 

than, 31 cents per pound reduced. 

Moreover, Environmental Defense stated, the exclusion of mass reduction in NHTSA’s 

analysis bears no relation to what will actually happen in the marketplace when standards 

are implemented. Environmental Defense argued that absent safety regulations 

prohibiting the use of mass reductions, manufacturers are likely to choose this 

compliance alternative in vehicles of all weights as a cost-effective way to comply with 

CAFE. Environmental Defense stated that NHTSA should consider the potential for 

mass reduction among its compliance alternatives for all light trucks. 

 

As stated above, the agency does not dictate which fuel-savings technologies must be 

applied to vehicles. Mass reduction is a compliance alternative for all light vehicles. 

However, one of the considerations in setting fuel economy standards is to set standards 

that will not lead to a reduction in safety. The standards proposed by the agency are 

those capable of being achieved by the manufacturers without the need to reduce safety. 

If the agency were to consider weight reduction as a compliance option, we are 

concerned that the resulting increased stringency would force unsafe downweighting. 

A group of experts at a workshop sponsored by the International Council on Clean 

Transportation (ICCT) examined many of the size/safety reports and wrote a June 2007 

report “Sipping Fuel and Saving Lives: Increasing Fuel Economy Without Sacrificing 

Safety.”31 NHTSA agrees with two of the three ICCT report findings. We agree that 

fuel economy technologies exist that don’t affect safety. We agree that reducing weight 

(on vehicles over 5, 000 lbs) can make certain vehicles less aggressive and reduce their 

weight and probably improve safety. Many, but not all of the experts at the workshop, 

agreed with the last conclusion: “Advanced technologies can decouple size from mass, 

creating important new possibilities for increasing fuel economy and safety without 

compromising functionality”. We continue to believe, until someone demonstrates to the 

contrary with some kind of rigorous, scientific analysis, that reducing weight on smaller 

lighter vehicles will only make them more dangerous in single-vehicle crashes, because 

of fundamental physics. 

A study examined similar safety issues - “The “Arms Race” on American Roads: The 

Effect of Sport Utility Vehicles and Pickup Trucks of Traffic Safety”, Michelle J. White, 

University of California San Diego, Journal of Law and Economics, Volume XLVII, 

October 2004. The White paper finds that “When drivers shift from cars to light trucks 

or SUVS, each crash that involves fatalities from light truck or SUV occupants that is 

prevented comes at a cost of at least 4.3 additional crashes that involve deaths of car 

occupants, pedestrians, bicyclists, or motorcyclists.” 

The White study is an analysis of NHTSA’s National Automotive Sampling System, 

General Estimates System and, as such, looks at the fatality risk given that a crash 

 

31 See www.theicct.org/documents/ICCT_SippingFuelFull_2007.pdf 
IV-15 

occurred. However, it does not control for VMT (likelihood of a crash given a mile of 

driving). Furthermore, the study does not address the safety of big cars vs. small cars or 

big LTVs versus small LTVs. Whether overall safety would be improved by shifting 

sales from SUV and pickups to passenger cars depends on what size of passenger cars 

you shifted to (see the table above), if you shifted to small or very small passenger cars, 

overall safety would decrease. 

Another study examined the size/safety issues – “The Fatality Risks of Sports Utility 

Vehicles, Vans, and Pickups Relative to Cars”, Ted Gayer, Georgetown University, The 

Journal of Risk and Uncertainty, 28-2, 103-133, 2004. This study finds that “Using a 

cross-sectional variation in snow depth as an instrument to determine VMT, the results 

suggest that light trucks are 2.63 to 4.00 times more likely to crash than cars.” “...once 

one adjusts for the greater frequency of crashes by light trucks, the aggregate risk they 

pose substantially dominates the risk from cars. Indeed a world of light trucks would 

lead to three to ten times more fatalities than a world of cars.” 

This study does not address the safety of big cars vs. small cars or big LTVs versus small 

LTVs. This analysis using snow depth exaggerates the difference in crash frequency and 

fatality rates between passenger cars and light trucks. Kahane’s study also adjusted the 

raw data for VMT, but we have used odometer readings by age of vehicle to control for 

VMT and found no such discrepancy in crash rates. The table above from the Kahane 

study does not show light trucks having substantially higher fatality rates than passenger 

cars. 

A 2001 study by Dr. Leonard Evans,32 modeled the risk of driver fatality in car 1 in a 

head-on collision with car 2. The equations in the report indicate that reducing the curb 

weight of car 1 would increase the risk to the driver of car 1, while reducing the curb 

weight of car 2 would decrease the risk to the driver of car 1. However, the equations 

also indicate that reducing the wheelbase of either car increases the total risk to both 

drivers. 

In a 2004 SAE paper, Dr. Evans claimed that increasing the amount of lightweight 

materials in vehicle design can provide reduced occupant risk both in two-vehicle and 

single-vehicle crashes, and also reduce risk for occupants in other vehicles33. However, 

he produced no analysis using real world data of vehicles with lightweight material to 

substantiate that claim34. 

 

32 Evans, L., “Causal Influence of Car Mass and Size on Driver Fatality Risk”, American Journal of Public 

Health, Vol. 91, No. 7, July 2001, pp 1076-1081. 33 Evans, L., “How to make a car lighter and safer,” SAE 2004-01-1 172, Society of Automotive 

Engineers, 11 March 2004. 

34 In NHTSA’s opinion, there are not enough vehicles made from lightweight material on the road to 

support an analysis using real world crash data. 
IV-16 

In an amicus brief, the Insurance Institute for Highway Safety35stated “Crash safety 

should be a consideration in how the balance is struck between programs to improve air 

quality and our efforts to protect people in crashes. Physics dictates that vehicle weight 

and size will always matter in a crash. Research in the private, public, and nonprofit 

sectors have demonstrated the relationship between vehicle size and weight and crash 

injuries. Simply put, Vermont’s regulation encourages production of smaller, lighter 

vehicles which will lead to increased traffic fatalities.” IIHS discusses research by 

NHTSA and IIHS that have led to the conclusion that “Vehicle downsizing has 

compromised safety because in most cases, smaller and lighter vehicles are less 

protective of their occupants than larger, heavier vehicles.” IIHS calculated the vehicle 

death rates by make model using driver deaths per million registered vehicle years, 

presented this data, and ranked them. “None of the 15 vehicles with the lowest driver 

death rates were mini or small models. ... Eleven of the 16 vehicles with the highest 

driver death rates were small cars and none were large or very large. ... The pattern is 

unmistakable. There is an inverse relationship between driver death rates and vehicle 

size...” 

Footprint and safety 

The impact of CAFE standards on motor vehicle and passenger safety has long been 

recognized as an integral part of the agency's process of determining maximum feasible 

average fuel economy. The agency notes that there are no compelling studies that 

quantify the precise and separate effects of vehicle size and weight on safety, in part 

because there is a high degree of correlation between size and weight among vehicles 

now in widespread use. The agency has determined that an attribute system based on 

footprint with the continuous function would minimize incentives for design changes that 

would reduce motor vehicle safety. In a weight-based system, a manufacturer can add 

weight to a vehicle in order to take advantage of a category with a lower fuel economy 

target. As discussed above, this up-weighting can have positive and negative safety 

implications, with possibly negative impacts for the fleet as a whole if weight is added to 

heavier light trucks. A manufacturer could not as readily increase footprint as it could 

vehicle weight. 

In order to increase footprint, a manufacturer would have to either extend a vehicle’s 

track width, wheelbase, or both. Maintaining and increasing track width should play a 

positive role in limiting rollover vulnerability, whereas maintaining and increasing 

wheelbase should play a positive role in improving handling – especially directional 

stability, which is crucial in preventing unintended off-road excursions that often lead to 

rollovers – and maximizing crush space (though total length is probably more closely 

correlated with crush space than is wheelbase). 

This is mentioned in Dr. Kahane’s response to safety studies submitted by Dynamic 

Research, Inc., by Marc Ross (University of Michigan) and Tom Wenzel (Lawrence 

Berkeley National Laboratory), and submitted by William E. Wecker Associates. 

 

35 Filed in the United States Court of Appeals for the Second Circuit, March 21, 2008, No. 07-4342-cv(L), 

March 21, 2008, Green Mountain Chrysler Plymouth Jeep..., by Michele Fields and Stephen L. Oesch of 

IIHS. 
IV-17 

Dr. Kahane wrote: 

”The objective of the NHTSA study was to calibrate the historical (MY 1991-99) 

relationships of vehicle mass and fatality risk, after controlling for driver 

age/gender, geographical location, and vehicle equipment. In this type of 

analysis, “vehicle mass” incorporates not only the effects of mass per se but also 

the effects of many other size attributes that are historically and/or causally 

related to mass, such as wheelbase, track width and structural integrity. (As 

vehicles get longer and wider, they almost always get heavier.) 

The study does not claim that mass per se is the specific factor that increases or 

decreases fatality risk (except in its role in determining the relative Delta V of two 

vehicles that collide). On the contrary, Chapter 5 of the NHTSA report shows 

that certain 4,000-pound SUVs have significantly higher fatal-crash rates than 

3,500-pound cars. The study only shows the historical relationship between mass 

– taking into account all the other size attributes that have typically varied with 

mass – and fatality risk, for vehicles of the same type. If historical relationships

between mass and other size attributes continue, in the absence of compelling 

reasons that would change those relationships, future changes in mass are likely to 

be associated with similar changes in fatality risk. (However, the increased use of 

advanced restraint systems and sophisticated crash avoidance safety devices in 

recent and future production vehicles could have a noticeable impact on the 

historical relationship between vehicle mass and fatality risk in future vehicle 

fleets.) 

In that sense, it is irrelevant whether mass, wheelbase, track width or some other 

attribute is the principal causal factor on fatality risk. If you decrease mass, you 

will also tend to reduce wheelbase, track width and other dimensions of size. If 

manufacturers respond to this proposal by building lighter vehicles of constant 

size, the historical relationship between mass and safety would gradually 

weaken.” 

Changes in technology could influence the relationship between weight and size. There 

is emerging evidence that vehicle weight can be reduced without reductions in size or 

safety through the use of high strength, lightweight materials. Currently, we do not 

observe many vehicles built with lightweight materials in the historical data and therefore 

cannot separate the impact of size versus weight when lightweight materials are utilized. 

However, the impact of weight, whether it comes from reducing size or material 

substitution, will be the same for single vehicle impacts (rollovers and fixed and nonfixed object impacts). 

Attribute-based standards eliminate the incentive for manufacturers to respond to CAFE 

standards in ways harmful to safety.36 Because each vehicle model has its own target 

 

36 The 2002 NAS Report, on which NHTSA relied in reforming the CAFE program for light trucks, 

described at length and quantified the potential safety problem with average fuel economy standards that 

specify a single numerical requirement for the entire industry. See National Academy of Sciences, 

“Effectiveness and Impact of Corporate Average Fuel Economy (CAFE) Standards,” (“NAS Report”) 
IV-18 

(based on the attribute chosen), attribute-based standards provide no incentive to build 

smaller vehicles simply to meet a fleet-wide average, because the smaller vehicles will be 

subject to more stringent fuel economy and emissions targets. 

The Impact of Emission Standards 

EPA Labeling Rule: Fuel Economy Labeling of Motor Vehicles: Revisions to 

Improve Calculation of Fuel Economy Estimates 

The EPA Fuel Economy Labeling Rule37 employs a new vehicle-specific, 5-cycle 

approach to calculating fuel economy labels which incorporates estimates of the fuel 

efficiency of each vehicle during high speed, aggressive driving, air conditioning 

operation and cold temperatures into each vehicle’s fuel economy label. The rule became 

effective January 26, 2007, and will take effect starting with MY 2008. 

The new testing procedures will combine measured fuel economy over the two current 

fuel economy tests, the FTP and HFET, as well as that over the US06, SC03 and cold 

FTP tests into estimates of city and highway fuel economy for labeling purposes. The 

test results from each cycle will be weighted to represent the contribution of each cycle’s 

attributes to on-road driving and fuel consumption. The labeling rule does not alter the 

FTP and HFET driving cycles, the measurement techniques, or the calculation methods 

used to determine CAFE. 

The EPA Labeling Rule will not impact CAFE standards or test procedures or other U.S. 

Government regulations.38 Rather, the changes to existing test procedures will allow for 

the collection of appropriate fuel economy data to ensure that existing test procedures 

better represent real-world conditions.39 Further, the labeling rule does not have a direct 

effect upon a vehicle’s weight, nor on the fuel economy level that a vehicle can achieve. 

Instead, the labeling law serves to provide consumers with a more accurate estimate of 

fuel economy based on more comprehensive factors reflecting real-world driving use. 

For this PRIA, the agency assumes that on-road mileage will be 80 percent of the 

measured CAFE, based on the FTP and HFET driving cycles, the measurement 

techniques, and the calculation methods used to determine CAFE. 

 National Academy Press, Washington, DC (2002), 5, finding 12. Available at

http://www.nap.edu/openbook.php?record_id=10172&page=R1 (last accessed Dec. 2, 2007). 37 See 71 FR 77872. 

38 See 71 FR 77872, section I.F. 

39 See 71 FR 77872, section II., IV. 
V-1 

V. FUEL ECONOMY ENHANCING TECHNOLOGIES AND THE VOLPE MODEL

A. Comparison of current with past approaches to analysis of technologies, their 

cost and effectiveness 

In the Agency’s last two rulemakings covering light truck CAFE standards for MYs 2005 

– 2007 and MYs 2008 – 2011, the agency relied on the 2002 National Academy of 

Sciences’ report, Effectiveness and Impact of Corporate Average Fuel Economy 

Standards (“the 2002 NAS Report”)40 for estimating potential fuel economy benefits and 

associated retail costs of applying combinations of technologies in 10 classes of 

production vehicles. The NAS cost and effectiveness numbers were the best available 

estimates at this time, determined by a panel of experts formed by the National Academy 

of Sciences, and the report had been peer reviewed by individuals chosen for their diverse 

perspectives and technical expertise in accordance with procedures approved by the 

Report Review Committee of the National Research Council. However, since the 

publication of the 2002 NAS Report, there has been substantial advancement in fuelsaving technologies, including technologies not discussed in the NAS Report that are 

expected to appear on vehicles in the MY 2011-2015 timeframe. There also have been 

reports issued and studies conducted by several other organizations and companies that 

discuss fuel economy technologies and their benefits and costs. NHTSA has contracted 

with the NAS to update the fuel economy section, Chapter 3, of the 2002 NAS Report. 

However, this update will not be available in time for this rulemaking. Due to the 

expedited nature of this rulemaking, NHTSA, in consultation with the Environmental 

Protection Agency (EPA), developed an updated technology cost and effectiveness list to 

be used in this notice. 

This list presents NHTSA and EPA technical staff’s current assessment of the costs and 

effectiveness from a broad range of technologies which can be applied to cars and lightduty trucks. EPA published the results of this collaboration in a report and submitted it to 

the NAS committee41. A copy of the report and other studies used in the technology 

update will be placed in NHTSA’s docket. 

NHTSA believes that the estimates used for this notice, which rely on the best available 

public and confidential information, are defensible and reasonable predictions for the 

next five years. Nevertheless, NHTSA still believes that the ideal source for this 

information comes from a peer reviewed process such as the NAS. NHTSA will 

continue to work with NAS to update this list on a five year interval as required by the 

Energy Independence and Security Act of 2007. 

 

The majority of the technologies discussed in this section are in production and available 

on vehicles today, either in the United States, Japan, or Europe. A number of the 

 

40 National Research Council, “Effectiveness and Impact of Corporate Average Fuel Economy (CAFE) 

Standards,” National Academy Press, Washington, DC (2002). Available at

http://www.nap.edu/openbook.php?isbn=0309076013 (last accessed Feb. 5, 2008). 41 EPA Staff Technical Report: Cost and Effectiveness Estimates of Technologies Used to Reduce Lightduty Vehicle Carbon Dioxide Emissions. EPA420-R-08-008, March, 2008 
V-2 

technologies are commonly available, while others have only recently been introduced 

into the market. In a few cases, we provide estimates on technologies which are not 

currently in production, but are expected to be so in the next few years. These 

technologies which can be applied to cars and trucks that are capable of achieving 

significant improvements in fuel economy and reductions in carbon dioxide emissions, 

and improve vehicle fuel economy, at reasonable costs. 

NHTSA and EPA conducted the technology examination using concepts from the 2002 

NAS report which constituted a starting point for the analysis. In the NAS Report, there 

were three exemplary technology paths or scenarios identified for each class of 

production vehicles, which lead to successively greater improvements in fuel 

consumption and greater costs. Path I included production-intent technologies that will 

be available within 10 years and could be implemented under current economic and 

regulatory conditions. Path II included more costly production-intent technologies that 

are technically feasible for introduction within 10 years if economic and regulatory 

conditions justify their use. Path III included emerging technologies that will be 

available within 10 to 15 years but that may require further development prior to 

commercial introduction. These three paths represented vehicle development steps that 

would offer increasing levels of fuel economy gains (as incremental gains) at 

incrementally increasing cost. As stated earlier, since the publication of the 2002 NAS 

Report, automotive technology has continued to advance and many of the technologies 

that were identified in the report as emerging have already entered the marketplace. 

In this rulemaking, NHTSA working with EPA have examined a variety of technologies 

and looked beyond path I and path II to path III and to emerging technologies beyond 

path III. These technologies were in their infancy when the 2002 NAS Report was being 

formulated. In addition, unlike for past rulemakings where NHTSA projected the use of 

different variants of a technology as a combined technology, in this rulemaking, NHTSA 

working with EPA examined advanced forms and subcategories of existing technologies 

and reflected the effectiveness and cost for each of the variants separately for all ten 

vehicle classes. The specific technologies affected are variable valve timing (VVT), 

variable valve lift and timing (VVLT) and cylinder deactivation. Manufacturers are 

currently using many different types of VVTs and VVLTs, which have a variety of 

different names and methods. This rulemaking employs specific cost and effectiveness 

estimates for variants of VVT, including Intake Camshaft Phasing (ICP), Coupled 

Camshaft Phasing (CCP), and Dual (Independent) Camshaft Phasing (DCP). It also 

employs specific cost and effectiveness estimates for variants of VVLT, including 

Discrete Variable Valve Lift (DVVL) and Continuous Variable Valve Lift (CVVL). We 

also now include the effectiveness and cost estimates for each of the variants of cylinder 

deactivation. The most common type of cylinder deactivation is one in which an eightcylinder overhead valve engine disables four of its cylinders under light loads. Cylinder 

deactivation could be incorporated on overhead cam engines, and can be applied to four 

and six cylinder engines as well (we have restricted application to 6 and 8 cylinder 

engines). Thus, the variants of cylinder deactivation that now have specific cost and 

effectiveness estimates include both overhead valve engine cylinder deactivation and 

overhead cam engine cylinder deactivation. 
V-3 

The update also revisited technology lead time issues and took a fresh look at technology 

application rates, how to link certain technologies to certain redesign and refresh patterns, 

synergistic impacts resulting from adding technology packaging, and learning costs. 

1. Data sources for technology assumptions 

A large number of technical reports and papers are available which contain data and 

estimates of the fuel economy improvements of various vehicle technologies. In addition 

to specific peer-reviewed papers respecting individual technologies, we also utilized a 

number of recent reports which had been utilized by various State and Federal Agencies 

and which were specifically undertaken for the purpose of estimating future vehicle fuel 

economy reduction effectiveness or improvements in fuel economy. The reports we 

utilized most frequently were: 

• 2002 National Academy of Science (NAS) report titled "Effectiveness and Impact 

of Corporate Average Fuel Economy Standards”. At the time it was published, the 

NAS report was considered by many to be the most comprehensive summary of 

current and future fuel efficiencies improvements which could be obtained by the 

application of individual technologies. The focus of this report was fuel economy, 

which can be directly correlated with CO2 emissions. The 2002 NAS report 

contains effectiveness estimates for ten different vehicle classifications (small car, 

mid-SUV, large truck, etc), but did not differentiate these effectiveness values 

across the classes. Where other sources or engineering principles indicated that a 

differentiation was warranted, we utilized the 2002 NAS effectiveness estimates 

as a starting point and further refined the estimate to one of the vehicle classes 

using engineering judgment or by consulting additional reliable sources. 

• 2004 Northeast States Center for a Clean Air Future (NESCCAF) report 

"Reducing Greenhouse Gas Emissions from Light-Duty Motor Vehicles". This 

report, which was utilized by the California Air Resources Board for their 2004 

regulatory action on vehicle CO2 emissions, includes a comprehensive vehicle 

simulation study undertaken by AVL, a world-recognized leader in automotive 

technology and engineering. In addition, the report included cost estimates 

developed by the Martec Group, a market-based research and consulting firm 

which provides services to the automotive industry. The NESCCAF report 

considered a number of technologies not examined in the 2002 NAS report. In 

addition, through the use of vehicle simulation modeling, the 2004 NESCCAF 

report provides a scientifically rigorous estimation of the synergistic impacts of 

applying multiple fuel economy technologies to a given vehicle. 

• 2006 Energy and Environmental Analysis Inc (EEA) report “Technology to 

Improve the Fuel Economy of Light Duty Trucks to 2015” Prepared for The U.S. 

Department of Energy and The U.S. Department of Transportation. This update of 

technology characteristics is based on new data obtained by EEA from technology 

suppliers and auto-manufacturers, and these data are compared to data from 
V-4 

studies conducted earlier by EEA, the National Academy of Sciences (NAS), the 

Northeast States Center for a Clean Air future (NESCCAF) and California Air 

Resources Board (CARB). 

• Data from Vehicle Manufacturers, Component Suppliers, and other reports. We 

also evaluated confidential data from a number of vehicle manufacturers as well 

as a number of technology component suppliers. In February of 2007, the NHTSA 

published a detailed Request for Comment (RFC) in the Federal Register. This 

RFC included, among other items, a request for information from automotive 

manufacturers and the public on the fuel economy improvement potential of a 

large number of vehicle technologies. The manufacturer’s submissions to this 

RFC were supplemented by confidential briefing and data provided by vehicle 

component suppliers, who for many of the technologies considered are the actual 

manufacturers of the specific technology and often undertake their own 

development and testing efforts to investigate the fuel economy improvement 

potential of their products. Manufacturers that provided NHTSA and EPA with 

fuel economy cost and effectiveness estimates include BMW, Chrysler, Ford, 

General Motors, Honda, Nissan, Toyota and Volkswagen. The major suppliers 

that provided NHTSA with fuel economy cost and effectiveness estimates include 

Borg-Warner, Bosch, Corning, Delphi, and Siemens. 

• Finally, to verify that the fuel economy cost and effectiveness estimates for each 

of the technologies was reasonable and within currently available estimates for 

these technologies, NHTSA examined those estimates provided by other reports 

or sources, such as the Martec (contained in the 2004 NESCAFF report) and 

Sierra Research reports42. 

2. Technologies and estimates of costs and effectiveness 

This section describes each technology and associated cost and effectiveness numbers. 

The technologies can be classified into five main groups similar to how they were 

classified in the NAS Report: engine technologies; transmission technologies; accessory 

technologies; vehicle technologies; and hybrid technologies. 

While NHTSA and EPA followed the general approach taken by the NAS in estimating 

the cost and effectiveness numbers, we decided to update some of these estimates to 

reflect better the changed marketplace and regulatory environment, as well as the 

advancement in and greater penetration of some production-intent and emerging 

technologies, which have led to lower costs. The values contained in the 2002 NAS 

report were used to establish a baseline for the fuel economy cost and effectiveness 

estimates for each of the technologies. We then examined all other estimates provided by 

manufacturers and major suppliers or other sources. In examining these values, we gave 

 

42 “Alternative and Future Technologies for Reducing Greenhouse Gas Emissions from 

Road Vehicles” Sierra Research Report for Environment Canada, 1999 (SR99-07-01). 

http://www.sierraresearch.com/ReportListing.htm 
V-5 

more weight to values or estimates provided by manufacturers that have already 

implemented these technologies in their fleet, especially those that have introduced them 

in the largest quantities. Likewise, for technologies that have not penetrated the fleet to 

date, but will by early in the next decade (according to confidential manufacturer plans), 

we gave more weight to values or estimates provided by manufacturers that have stated 

that they will be introducing these technologies in their fleet, especially those that plan to 

introduce them in the largest quantities. In addition, for the technologies that will appear 

on vehicles by early in the next decade, we carefully examined the values provided by 

those suppliers who have developed these technologies and may have contracts in place 

to provide them to manufacturers. 

Because not all technologies can be applied on all types of vehicles, engines or 

transmissions, we separately evaluated 10 classes of vehicles to estimate fuel economy 

cost and effectiveness for each of the technologies. As discussed above, these ten 

classes, also used in NHTSA’s 2006 light truck CAFE rule, were derived from the 2002 

NAS Report, which estimated the feasibility, potential incremental fuel consumption 

benefit and the incremental cost of three product development paths for the following ten 

vehicle classes: subcompact passenger cars, compact passenger cars, midsize passenger 

cars, large passenger cars, small sport utility vehicles, midsize sport utility vehicles, large 

sport utility vehicles, small pickups, large pickups, and minivans. 

The application of technologies to a vehicle class is limited not only by whether the 

manufacturer is capable of applying it within a particular development cycle, but also by 

whether the technology may physically be applied to the vehicle. For example, 

continuously variable transmissions (CVTs) were only allowed to be projected on 

vehicles with unibody construction, which includes all passenger cars and minivans and 

some small and midsize SUVs. CVTs could not be projected for use on vehicles with 

ladder-frame construction, which includes all pickups and large SUVs and some small 

and midsize SUVs. Another example is cylinder deactivation being limited to vehicles 

with 6- or 8-cylinder engines. To simplify the analysis, NHTSA assumed that each class 

of vehicles would typically have vehicle construction and engines with a specific number 

of cylinders that is most representative of that vehicle class. 

Although we looked at ten vehicle classes separately, for some technologies the estimated 

incremental fuel consumption benefit and incremental cost were the same across all 

vehicle classes (as for engine accessory improvement), while for other technologies the 

estimated incremental fuel consumption benefit and incremental cost differed across 

classes (as for hybrid drivetrains). The main difference was with which path(s) each 

technology was expected to be associated. . 

The exact cost and benefit of a given technology depends on specific vehicle 

characteristics (size, weight, base engine, etc.) and the existence of additional 

technologies that were already applied to the vehicle. In the section below, ranges of 

incremental cost and fuel consumption reduction values are listed where the values 

depend on vehicle characteristics and are independent of the order in which they are 

applied to a vehicle. All costs, which are reflective of estimated retail price equivalents 
V-6 

(RPEs) were inflated by the producer price index (if needed) and are presented in year 

2006 dollars, because this is the last year for which final economic indexing is available. 

Some cost estimates are based on supplier costs. In those instances, multipliers were 

included in those costs so that they would be treated in the same manner as cost estimates 

that are based on manufacturer costs. These incremental values were calculated by 

subtracting out all same-path synergies associated with a given technology and any 

preceding items on the same path. Essentially, the incremental percent reduction in fuel 

consumption and cost impacts represent improvements beyond the ones realized due to 

technologies already applied to the vehicle. As an example, a 5-speed automatic 

transmission could incrementally reduce fuel consumption by 2 to 3 percent at an 

incremental cost of $75 to $165 per vehicle, relative to a 4-speed automatic transmission. 

In turn, a 6-speed automatic transmission could incrementally reduce fuel consumption 

by 4.5 to 6.5 percent at an incremental cost of $10 to $20 per vehicle, relative to a 5-

speed transmission. 

NHTSA acknowledges that this approach is different from the one it followed in 

establishing the reformed light truck standards for MYs 2008-2011, where we relied 

nearly exclusively on the 2002 NAS report’s estimates. Our preference remains to rely 

upon peer-review and credible studies, such as the 2002 NAS report; however we believe 

that the estimates made by the joint EPA/NHTSA team are accurate and defensible. The 

agency seeks comments on our assumptions and the cost, effectiveness and availability 

estimates provided. NHTSA also seeks comments on whether the order in which these 

technologies was applied by the Volpe model is proper and whether we have accurately 

accounted for technologies already included on vehicles and whether we have accurately 

accounted for technologies that are projected to be applied to vehicles. The agency also 

seeks comments on the “synergy” factors (discussed below) it has applied in order to 

adjust the estimated incremental effectiveness of some pairs of technology and on 

whether similar adjustments to the estimated incremental cost of some technologies 

should be made. In preparation for a final rule, NHTSA intends to update its technologyrelated methodologies and estimates, and expects that these anticipated updates will 

affect the form and stringency of the final standards. 

a. Engine technologies 

Low-Friction Lubricants 

The use of lower viscosity engine and transmission lubricants can reduce fuel 

consumption. More advanced multi-viscosity engine and transmission oils are now 

available with improved performance in a wider temperature band, with better lubricating 

properties. However, even without any changes to fuel economy standards, most MY 

2011-2015 vehicles are likely to use 5W-30 motor oil, and some will use even less 

viscous oils, such as 5W-20 or possibly even 0W-20 to reduce cold start friction. This 

may directionally benefit the fuel economy improvements of valvetrain technologies such 

as cylinder deactivation, which rely on a minimum oil temperature (viscosity) for 

operation. Most manufacturers therefore attributed smaller potential fuel economy 

reductions and cost increases to lubricant improvements. 
V-7 

The NAS Report projected that low-friction lubricants could incrementally reduce fuel 

consumption by 1 percent at an incremental cost of $8 to $11.43 The NESCCAF study 

projected that low-friction lubricants could incrementally reduce fuel consumption by 1 

percent at an incremental cost of $5 to $15; while the EEA report projected that lowfriction lubricants could incrementally reduce fuel consumption by 1 percent at an 

incremental cost of $10 to $20. In contrast, manufacturer data projected an estimated fuel 

consumption potential of 0% to 1% at an incremental cost that ranged from $1 to $11, 

with many of them stating the costs as ranging from $1 to $5. NHTSA believes that these 

manufacturer estimates are more accurate and estimates that low-friction lubricants could 

reduce fuel consumption by 0.5 percent for all vehicle types at an incremental cost of $3, 

which represents the mid-point of $2.50, rounded up to the next dollar. 

Reduction of Engine Friction Losses 

All reciprocating and rotating components in the engine are candidates for friction 

reduction, and minute improvements in several components can add to a measurable fuel 

economy improvement. The amount of energy an engine loses to friction can be reduced 

in a variety of ways. Improvements in the design of engine components and subsystems 

will result in friction reduction, improved engine operation, greater fuel economy and 

reduced emissions. Examples include low-tension piston rings, roller cam followers, 

crankshaft design, improved material coatings, material substitution, more optimal 

thermal management, piston surface treatments, and as lubricant friction reduction. 

Additionally, as computer-aided modeling software continues to improve, more 

opportunities for incremental friction reduction might become apparent. Even without 

any changes to fuel economy standards, most MY 2010-2015 vehicles are likely to 

employ one or more such techniques to reduce engine friction and other mechanical and 

hydrodynamic losses. 

The NAS Report predicted that such technologies could incrementally reduce fuel 

consumption by 1 to 5 percent at an incremental cost of $36 to $146. NESCCAF 

predicted that such technologies could incrementally reduce fuel consumption by 0.5 

percent at an incremental cost of $5 to $15; while the EEA report predicted that such 

technologies could reduce fuel consumption at an incremental cost of $10 to $55. 

Confidential manufacturer data indicates that engine friction reduction could 

incrementally reduce fuel consumption by 1 to 3 percent at an incremental cost of $0 to 

$168. Based on available information from these reports and confidential manufacturer 

data, NHTSA estimates that friction reduction could reduce fuel consumption for all 

vehicles by 1 to 3 percent at a cost of $21 per cylinder. Thus, the incremental cost of 

engine friction reduction for a 4-cylinder engine is $0 to $84 (applicable to subcompact 

and compact cars); for a 6-cylinder engine is $0 to $126 (applicable to midsize cars, large 

cars, small pickups, small SUVs, minivans and midsize SUVs); and for an 8-cylinder 

engine is $0 to $168 (applicable to large pickups and SUVs). 

 

43 The price increases noted in this chapter are slightly higher than shown in the NAS study, since they 

have been converted into calendar year 2006 prices. 
V-8 

Multi-Valve Overhead Camshaft Engine 

It appears likely that many vehicles would still use overhead valve (OHV) engines with 

pushrods and one intake and one exhaust valve per cylinder during the early part of the 

next decade. Engines with overhead cams (OHC) and more than two valves per cylinder 

achieve increased airflow at high engine speeds and reductions of the valve train’s 

moving mass and enable central positioning of spark plugs. Such engines, which are 

already used in some light trucks, typically develop higher power at high engine speeds. 

The NAS Report projected that multi-valve OHC engines could incrementally reduce fuel 

consumption by 2 percent to 5 percent at an incremental cost of $109 to $146, and 

NHTSA found no sources to update these projections. 

For purposes of this rule, OHV engines and OHC engines were considered separately, and the 

model was generally not allowed to apply multivalve OHC technology to OHV engines, except 

where continuous variable valve timing and lift (CVVL) is applied to OHV engines. In that 

case, the model assumes conversion to DOHC valvetrain, because DOHC valvetrains are 

prerequisites for the application of any advanced engine technology over and above CVVL. 

Since applying CVVL to an OHV is the last improvement that could be made to such an 

engine, it’s logical to assume that manufacturers would redesign that engine as a DOHC and 

include CVVL as part of that redesign. 

For 4-cylinder engines we estimated that the cost to redesign an OHV engine as a DOHC 

that includes CVVL would be $599 ($169 for conversion to DVVL, $254 for conversion 

to CVVL, and $176 for conversion to DOHC, which comprises an additional camshaft 

and valves), with estimated fuel consumption reduction of 2 to 3 percent. For 6-cylinder 

engines we estimated that the cost to redesign an OHV engine as a DOHC that includes 

CVVL would be $1262 ($246 for conversion to DVVL, $488 for conversion to CVVL, 

and $550 for conversion to DOHC, which comprises an additional camshaft and valves), 

with estimated fuel consumption reduction of 1 to 4 percent. For 8-cylinder engines we 

estimated that the cost to redesign an OHV engine as a DOHC that includes CVVL 

would be $1380 ($322 for conversion to DVVL, $508 for conversion to CVVL, and $550 

for conversion to DOHC, which comprises an additional camshaft and valves), with 

estimated fuel consumption reduction of 2 to 3 percent. Incremental cost estimates for 

DVVL and CVVL are discussed below. 

NHTSA believes that the NESCCAF report and confidential manufacturer data are more 

accurate, and thereby estimates that a conversion of an OHV engine to a DOHC engine with 

CVVL could incrementally reduce fuel consumption by 1 to 4 percent at an incremental cost of 

$599 to $1,380 compared to an OHV with VVT. 

Cylinder Deactivation 

For the vast majority of vehicles, each cylinder is always active while the engine is 

running. Under partial load conditions, the engine’s specific fuel consumption could be 

reduced if some cylinders could be disabled, such that the active cylinders operate at 

higher load. In cylinder deactivation, some (usually half) of the cylinders are “shut 
V-9 

down” during light load operation – the valves are kept closed, and no fuel is injected – 

as a result, the trapped air within the deactivated cylinders is simply compressed and 

expanded as an air spring, with minimal friction and heat losses. The active cylinders 

combust at almost double the load required if all of the cylinders were operating. 

Pumping losses are significantly reduced as long as the engine is operated in this “partcylinder” mode. 

The theoretical engine operating region for cylinder deactivation is limited to no more 

than roughly 50% of peak power at any given engine speed. In practice, however, 

cylinder deactivation is employed primarily at lower engine cruising loads and speeds, 

where the transitions in and out of deactivation mode are less apparent to the operator and 

where the noise and vibration (NVH) associated with fewer firing cylinders may be less 

of an issue. Manufacturers are exploring the possibilities of increasing the amount of time 

that part-cylinder mode might be suitable to a vehicle with more refined powertrain and 

NVH treatment strategies. 

General Motors and Chrysler Group have incorporated cylinder deactivation across a 

substantial portion of their V8-powered lineups. Honda (Odyssey, Pilot) and General 

Motors (Impala, Monte Carlo) offer V6 models with cylinder deactivation. 

There are two variants of cylinder deactivation. The most common type of cylinder 

deactivation is one in which an eight-cylinder overhead valve engine disables four 

cylinders under light loads. Thus an eight-cylinder engine could disable four cylinders 

under light loads, such as when the vehicle is cruising at highway speed. This technology 

could be applied to four and six cylinder engines as well. General Motors and Chrysler 

Group have incorporated cylinder deactivation across a substantial portion of their V8-

powered overhead valve lineups. 

Cylinder deactivation could be incorporated on overhead cam engines and can be applied 

to four and six cylinder engines as well. Honda has already begun offering three V6 

models with cylinder deactivation (Accord, Odyssey, and Pilot) and GM will soon release 

cylinder deactivation on its 3.9L 6-cylinder engine. Fuel economy improvement 

potential scales roughly with engine displacement-to-vehicle weight ratio: the higher 

displacement-to-weight vehicles, operating at lower relative loads for normal driving, 

have the potential to operate in part-cylinder mode more frequently. 

Honda’s technology includes the use of active engine mounts and noise damping amongst 

other items added to its V6 engines with cylinder deactivation. This, of course increases 

the cost relative to a four or eight cylinder OHC engine. 

Some manufacturers are getting results in excess of 6 percent and most are at the high 

end of the range. This higher number is supported by official fuel economy test data on a 

V6 Honda Odyssey with cylinder deactivation compared to the same vehicle (and engine 

displacement) without cylinder deactivation and by confidential manufacturer 

information. 
V-10 

The NAS Report projected that cylinder deactivation could incrementally reduce fuel 

consumption by 3 percent to 6 percent at an incremental cost of $112 to $252. The 

NESCCAF study projected that cylinder deactivation could incrementally reduce fuel 

consumption by 1.7 percent to 4.2 percent at an incremental cost of $161 to $210; while 

the EEA report projected that cylinder deactivation could incrementally reduce fuel 

consumption by 5.2 percent to 7.2 percent at an incremental cost of $105 to $135. 

Confidential manufacturer data and official fuel economy test data indicates that cylinder 

deactivation could incrementally reduce fuel consumption by at least 6 percent at an 

incremental cost of $203 to $229. NHTSA believes that these manufacturer estimates 

are more accurate and thus estimates that cylinder deactivation could reduce fuel 

consumption by 4.5 percent to 6 percent at an incremental cost of $203 to $229. 

Variable Valve Timing 

Variable valve timing is a classification of valvetrain designs that alter the timing of the 

intake valve, exhaust valve, or both, primarily to reduce pumping losses, increase specific 

power, and control residual gases. VVT reduces pumping losses when the engine is 

lightly loaded by positioning the valve at the optimum position needed to sustain 

horsepower and torque. VVT can also improve thermal efficiency at higher engine 

speeds and loads. Additionally, VVT can be used to alter (and optimize) the effective 

compression ratio where it is advantageous for certain engine operating modes. 

Variable valve timing has been available in the market for quite a while. By the early 

1990s, VVT had made a significant market penetration with the arrival of Honda’s 

“VTEC” line of engines. VVT has now become a widely adopted technology: for the 

2007 model year, over half of all new cars and light trucks have engines with some 

method of variable valve timing. Therefore, the degree of further improvement across 

the fleet is limited to vehicles that have not already implemented this technology. 

Manufacturers are currently using many different types of variable valve timing, which 

have a variety of different names and methods. The major types of VVT are listed 

below: 

Intake Camshaft Phasing (ICP) 

Valvetrains with ICP – the simplest type of cam phasing - can modify the timing of the 

intake valve while the exhaust valve timing remains fixed. This requires the addition of a 

cam phaser for each bank of intake valves on the engine. An in-line 4-cylinder engine has 

one bank of intake valves, while V-configured engines would have two banks of intake 

valves. The NAS Report projected that ICP could incrementally reduce fuel consumption 

by 3 percent to 6 percent at an incremental cost of $35; while the EEA report projected 

that ICP could reduce fuel consumption at an incremental cost of $35. The NESCCAF 

study projected that ICP could incrementally reduce fuel consumption by 1 percent to 2 

percent at an incremental cost of $49. Consistent with the EEA report and NESCCAF 

study, we have used this $35 manufacturer cost to arrive at incremental cost of $59 per 

cam phaser or $59 for an in-line 4 cylinder and $119 for a V-type, thus NHTSA estimates 
V-11 

that ICP could incrementally reduce fuel consumption by 1 to 2 percent at an incremental 

cost of $59 to $119 above fixed-cam valvetrains. 

Coupled Camshaft Phasing (CCP) 

Coupled (or coordinated) cam phasing is a design in which both the intake and exhaust 

valve timing are varied with the same cam phaser. For an overhead cam engine, the same 

phaser added for ICP would be used for CCP control. As a result, its costs should be 

identical to those for ICP. For an overhead valve engine, only one phaser would be 

required for both inline and V-configured engines since only one camshaft exists. 

Therefore, for overhead valve engines, the cost is estimated at $59 regardless of engine 

configuration, using the logic provided for ICP. 

The NESCCAF study projected that CCP could incrementally reduce fuel consumption 

by 1 percent to 3 percent above that obtained by ICP. Confidential manufacturer data 

also projects that that CCP could incrementally reduce fuel consumption by 1 percent to 3 

percent above that obtained by ICP. According to the NESCCAF report and confidential 

manufacturer data, NHTSA estimates that CCP could incrementally reduce fuel 

consumption by 1 to 3 percent at an incremental cost of $59 to $119. 

Dual (Independent) Camshaft Phasing (DCP) 

The most flexible VVT design is dual cam phasing, where the intake and exhaust valve 

opening and closing events are controlled independently. This design allows the option 

of controlling valve overlap, which can be used as an internal EGR strategy. Our 

estimated incremental compliance cost for this technology is built upon that for VVT-ICP 

where an additional cam phaser is added to control each bank of exhaust valves less the 

cost to the manufacturer of the removed EGR valve. The incremental compliance cost for 

a 4-cylinder engine is estimated to be $59 for each bank of valves, plus an estimated 

piece cost of $30 for the valves, for a total incremental compliance cost of $89. The 

incremental compliance cost for a V6 or a V8 engine is estimated to be $59 for each bank 

of intake valves (i.e., two banks times $59/bank = $119), $59 for each bank of exhaust 

valves (i.e., another $119) minus an estimated $29 incremental compliance cost for the 

removed EGR valve; the total incremental compliance cost being $209. 

According to the NESCCAF report and confidential manufacturer data, it is estimated 

that DCP could incrementally reduce fuel consumption by 1 to 3 percent at an 

incremental cost of $89 to $209 compared to engines with ICP or CCP. 

Because ICP and CCP have the same cost and similar effectiveness, it is assumed that 

manufacturers will choose the technology that best fits the specific engine architecture 

and application. 

Variable Valve Lift and Timing 
V-12 

Some vehicles have engines for which both valve timing and lift can be at least partially 

optimized based on engine operating conditions. Engines with variable valve timing and 

lift (VVLT) can achieve further reductions in pumping losses and further increases in 

thermal efficiency. Controlling the lift height of the valves provides additional flexibility 

and potential for further fuel consumption reduction. By reducing the valve lift, engines 

can decrease the volumetric flow at lower operating loads, improving fuel-air mixing and 

in-cylinder mixture motion which results in improved thermodynamic efficiency and also 

potentially reduced overall valvetrain friction. Also, by moving the throttling losses 

further downstream of the throttle valve, the heat transfer losses that occur from the 

throttling process are directed into the fresh charge-air mixture just prior to compression, 

delaying the onset of knock-limited combustion processes. At the same time, such 

systems may also incur increased parasitic losses associated with their actuation 

mechanisms. 

The NAS report projected that VVLT could incrementally reduce fuel consumption by 1 

to 2 percent over VVT alone at an incremental cost of $73 to 218. 

Manufacturers are currently using many different types of variable valve lift and timing, 

which have a variety of different names and methods. The major types of VVLT are 

listed below: 

Discrete Variable Valve Lift 

Discrete variable valve lift (DVVL) is a method in which the valvetrain switches between 

multiple cam profiles, usually 2 or 3, for each valve. These cam profiles consist of a low 

and a high-lift lobe, and may include an inert or blank lobe to incorporate cylinder 

deactivation (in the case of a 3-step DVVL system). According to the NESCCAF report 

and confidential manufacturer data, it is estimated that DVVL could incrementally reduce 

fuel consumption by 0.5 to 3 percent at an incremental cost of $169 to $322 compared to 

an engine with VVT and cylinder deactivation depending on engine size and overhead 

cam versus overhead valve engines. Included in this cost estimate is $25 for controls and 

associated oil supply needs (these costs not reflected in the NESCCAF study). We also 

project that a single valve lifter could control valve pairs, thus engines with dual intake 

and/or dual exhaust valves would require only one lifter per pair of valves. Due to this, 

the estimated costs for applying DVVL to overhead cam and overhead valve engines are 

the same. 

Continuous Variable Valve Lift 

Continuous variable valve lift (CVVL) employs a mechanism that varies the pivot point 

in the rocker arm. This design is realistically limited to overhead cam engines. 

Currently, BMW has implemented this type of system in its Valvetronic engines, which 

employs fully flexible valve timing to allow an extra set of rocker arms to vary the valve 

lift height. CVVL enables intake valve throttling in engines, which allows for the use of 

more complex systems of sensors and electronic controls to enable further optimization 

of valve lift. 
V-13 

The NESCCAF study projected incremental costs from $210 to $420, depending on 

vehicle class, while the EEA report projected incremental costs of $180 to $350, 

depending on vehicle class. Confidential manufacturer data projects that CVVL could 

incrementally reduce fuel consumption by 1.5 by 4 percent at an incremental cost of $200 

to $515. NHTSA believes that these manufacturer estimates are more accurate than 

NESCCAF estimates, thus it gives more weight to them. According to the NESCCAF 

report and confidential manufacturer data, NHTSA estimates that CVVL could 

incrementally reduce fuel consumption by 1.5 by 4 percent at an incremental cost of $254 

to $508 compared to an engine with VVT and cylinder deactivation with cost estimates 

varying from $254, $466, and $508 for a 4-, 6-, and 8-cylinder engine, respectively. 

Camless Valve Actuation 

Camless valve actuation relies on electromechanical actuators instead of camshafts to 

open and close the cylinder valves. When electromechanical actuators are used to replace 

cams and coupled with sensors and microprocessor controls, valve timing and lift can be 

optimized over all conditions. An engine valvetrain that operates independently of any 

mechanical means provides the ultimate in flexibility for intake and exhaust timing and 

lift optimization. With it comes infinite valve overlap variability, the rapid response 

required to change between operating modes (such as HCCI and GDI), intake valve 

throttling, cylinder deactivation, and elimination of the camshafts (reduced friction). This 

level of control can enable even further incremental reductions in fuel consumption. 

Camless valvetrains have been under research for many decades due to the design 

flexibility and the attractive fuel economy improvement potential they might provide. 

Despite the promising features of camless valvetrains, significant challenges remain. 

High costs and design complexity have reduced manufacturers’ enthusiasm for camless 

engines in light of other competing valvetrain technologies. The advances in VVT, 

VVLT, and cylinder deactivation systems demonstrated in recent years have reduced the 

potential efficiency advantage of camless valvetrains. 

The NAS Report projected that camless valve actuation could incrementally reduce fuel 

consumption by 5 to 10 percent over VVLT at an incremental cost of $336 to $673. 

Confidential manufacturer information provides incremental fuel consumption losses that 

range from 2 to 10 percent at costs that range from $300 to $1,100. The NESCCAF 

study projected that camless valve actuation could incrementally reduce fuel consumption 

by 11 to 13 percent at an incremental cost of $805 to $1,820; while the EEA report 

projected that camless valve actuation could incrementally reduce fuel consumption by 

10 to 14 percent at an incremental cost of $210 to $600. These benefits and costs are 

believed to be incremental to engines with VVT. 

In reviewing our sources for costs, we have determined that the adjusted costs presented 

in the 2002 NAS study, which ranged from $336 to $673 - depending on vehicle class – 

represent the best available estimates. Subtracting out the improvements associated with 
V-14 

the application of VVLT provides an estimated fuel consumption reduction of 2.5 

percent. 

Stoichiometric Gasoline Direct Injection Technology 

Gasoline direct injection (GDI, or SIDI) engines inject fuel at high pressure directly into 

the combustion chamber (rather than the intake port in port fuel injection). Direct 

injection improves cooling of the air/fuel charge within the cylinder, which allows for 

higher compression ratios and increased thermodynamic efficiency. Injector design 

advances and increases in fuel pressure have promoted better mixing of the air and fuel, 

enhancing combustion rates, increasing exhaust gas tolerance and improving cold start 

emissions. GDI engines achieve higher power density and match well with other 

technologies, such as boosting and variable valvetrain designs. 

Several manufacturers (Audi, BMW, and Volkswagen) have recently released GDI 

engines while General Motors and Toyota will be introducing GDI engines. In addition, 

BMW and GM have announced their plans to dramatically increase the number of GDI 

engines in their portfolios. 

The NESCCAF report projected that the incremental cost for GDI of $189 to $294; while 

the EEA report projected an incremental cost of $77 to $135. Confidential manufacturer 

data provides data with higher upper end costs than these estimates, with incremental fuel 

consumption estimates ranging from 1 to 2 percent. For our analysis, we have estimated 

the costs of individual components of a GDI system and used a “bottom up” approach 

looking at incremental costs for injectors, fuel pumps, etc., to arrive at system 

incremental compliance costs ranging from $122 to $420 for small cars and up to $228 to 

$525 for large trucks. The lower end of the ranges represent our best estimate 

using a bottom up approach while the upper end of the ranges represent levels more 

consistent with the manufacturer CBI submittals. As a result, we estimate that 

stoichiometric GDI could incrementally reduce fuel consumption by 1 to 2 percent at an 

incremental cost of $122 to $525 compared to engines of similar power output. 

Gasoline Engine Turbocharging and Engine Downsizing 

The specific power of a naturally aspirated engine is limited, in part, by the rate at which 

the engine is able to draw air into the combustion chambers. Turbocharging and 

supercharging are two methods to increase the intake manifold pressure and 

cylinder charge-air mass above naturally aspirated levels. By increasing the pressure 

differential between the atmosphere and the charging cylinders, superchargers and 

turbochargers increase this available airflow, and thus increase the specific power level, 

and with it the ability to reduce engine size while maintaining performance. This 

effectively reduces the pumping losses at lighter loads in comparison to a larger, naturally 

aspirated engine, while at the same time reducing net friction losses. 

Almost every major manufacturer currently markets a vehicle with some form of 

boosting. While boosting has been a common practice for increasing performance for 

several decades, it has considerable fuel economy potential when the engine displacement 
V-15 

is reduced. Specific power levels for a boosted engine often exceed 100 hp/L - compared 

to average naturally aspirated engine power densities of roughly 70 hp/L. As a result, 

engines can conservatively be downsized roughly 30 percent to achieve similar peak 

output levels. 

In the last decade, improvements to turbine design have improved their reliability and 

performance across the entire engine operating range. New variable geometry turbines 

spool up to speed faster (eliminating the once-common “turbo lag”) while maintaining 

high flow rates for increased boost at high speeds. 

Turbocharging and downsizing involves the addition of a boost system, removal of two 

cylinders in most cases (from an 8-cylinder to a 6, or a 6 to a 4) and associated valves, 

and the addition of some form of cold start control system (e.g., air injection) to address 

possible cold start emission control. The NAS Report projected that turbocharging and 

downsizing could incrementally reduce fuel consumption by 5 to 7 percent at an 

incremental cost of $364 to $582. The EEA report projected turbocharging and 

downsizing could incrementally reduce fuel consumption by 5.2 to 7.8 percent. 

In developing estimated costs for turbocharging and downsizing an engine, NHTSA, in 

conjunction with EPA, relied upon piece cost estimates contained in the NESCCAF 

report. The cost estimates provided by the NESCCAF report are as follows: $600 for the 

turbocharger and associated parts; $90 for an air injection pump and associated parts 

(each turbocharger requires an air injection pump); $75 per cylinder and associated 

components: $15 per each valve and associated components; and $150 per camshaft. 

In developing the cost estimates for each of the ten classes of vehicles, we determined the 

most logical type of downsizing that would occur for each class and starting with the 

turbocharger and air injector cost, either added or deleted cost, depending on the 

situation. These cost estimates are incremental to an engine with GDI. For subcompact 

and compact cars, we determined that the downsizing wouldn’t involve the removal of 

any cylinders, valves and camshafts, but instead would result in a manufacturer using a 

smaller displacement 4-cylinder engine and adding the turbocharger and the air injector 

to the smaller engine. Thus, for subcompact and compact cars, we estimated the cost of 

turbocharging and downsizing to be $690 ($600 for the turbocharger plus $90 for the air 

injector). 

For large trucks and large SUVs we determined that the most logical engine downsizing 

would involve replacing an 8-cylinder overhead valve engine with a turbocharged 6-

cylinder dual overhead cam engine. This change would result in the removal of 2 

cylinders, and the addition of a turbocharger, an air injector, 8 valves and 2 camshafts. 

Thus, for, we have estimated the cost of turbocharging and downsizing to be $810 ($600 

for the turbocharger plus $90 for the air injector, plus $120 for eight valves plus $150 for 

a camshaft and minus $150 for the removal of two cylinders). 

For midsize cars, large cars, small trucks, small SUVs, midsize SUVs and minivans, we 

determined that the most logical engine downsizing would involve replacing a 6-cylinder 
V-16 

dual overhead cam engine with a turbocharged 4-cylinder dual overhead cam engine. 

This change would result in the removal of 2 cylinders, 8 valves and 2 camshafts and the 

addition of a turbocharger and air injector. Thus, for, we have estimated the cost of 

turbocharging and downsizing to be $120 ($600 for the turbocharger plus $90 for the air 

injector, minus $150 for the removal of two cylinders, minus $120 for the removal of 

eight valves and minus $300 for the removal of two camshafts). 

Thus, we have estimated the cost for a boosted/downsized engine system at $690 for 

small cars, $810 for large trucks, and $120 for other vehicle classes. Projections of the 

fuel consumption reduction potential of a turbocharged and downsized engine from the 

NAS Report are backed by EEA estimates and confidential manufacturer data. . 

According to the NAS Report, the EEA report, cost estimates developed in conjunction 

with EPA and confidential manufacturer data, NHTSA estimates that downsized 

turbocharged engines could incrementally reduce fuel consumption from 5 to 7.5 percent 

at an incremental cost of $120 to $810. 

Diesel Engine 

Diesel engines have several characteristics that give them superior fuel efficiency to 

conventional gasoline, spark-ignited engines. Pumping losses are greatly reduced due to 

lack of (or greatly reduced) throttling. The diesel combustion cycle operates at a higher 

compression ratio, with a very lean air/fuel mixture, and typically at much higher torque 

levels than an equivalent-displacement gasoline engine. Turbocharged light-duty diesels 

typically achieve much higher torque levels at lower engine speeds than equivalentdisplacement naturally-aspirated gasoline engines. Additionally, diesel fuel has higher 

energy content per gallon. However, diesel engines have emissions characteristics that 

present challenges to meeting Tier 2 emissions standards. 

Compliance strategies are expected to include a combination of combustion 

improvements and after-treatment. Several key advances in diesel technology have made 

it possible to reduce emissions coming from the engine (prior to after-treatment). These 

technologies include improved fuel systems (higher pressures and more responsive 

injectors), advanced controls and sensors to optimize combustion and emissions 

performance, higher EGR levels to reduce NOx, lower compression ratios and advanced 

turbocharging systems. 

For after-treatment, the traditional 3-way catalyst found on gasoline-powered vehicles is 

ineffective due to the lean-burn combustion of a diesel. All diesels will require a 

particulate filter, an oxidation catalyst, and a NOx reduction strategy to comply with Tier 

2 emissions standards. 

The NOx reduction strategies most common are outlined below: 

Lean NOx Trap Catalyst After-Treatment 

A lean NOx trap (LNT) operates, in principle, by storing NOx (NO and NO2) when the 

engine is running in its normal (lean) state. When the control system determines (via 
V-17 

mathematical model or a NOx sensor) that the trap is saturated with NOx, it switches to a 

rich operating mode. This rich mode produces excess hydrocarbons that act as a reducing 

agent to convert the stored NOx to N2 and water, thereby “regenerating” the LNT and 

opening up more locations for NOx to be stored. LNTs are sensitive to sulfur deposits 

which can reduce catalytic performance, but periodically undergo a desulfation engine 

operating mode to clean it of sulfur buildup. 

According to confidential manufacturer data, NHTSA estimates that LNT-based diesels 

can incrementally reduce fuel consumption by 8 to 15 percent at an incremental cost of 

$1,500 to $1,600 compared to a direct injected turbocharged and downsized internal 

combustion engine. These costs are based on a “bottom up” cost analysis that was 

performed with EPA which then subtracted the costs of all previous steps on the decision 

tree prior to diesel engines. 

Selective Catalytic Reduction NOx After-Treatment 

SCR uses a reductant (typically, ammonia derived from urea) continuously injected into 

the exhaust stream ahead of the SCR catalyst. Ammonia combines with NOx in the SCR 

catalyst to form N2 and water. The hardware configuration for an SCR system is more 

complicated that that of an LNT, due to the onboard urea storage and delivery system 

(which requires a urea pump and injector into the exhaust stream). While there is no 

required rich engine operating mode prescribed for NOx reduction, the urea is typically 

injected at a rate of 3 to 4 percent of that of fuel consumed. Manufacturers designing 

SCR systems are intending to align urea tank refills with standard maintenance practices 

such as oil changes. Incremental fuel consumption reduction estimates for diesel engines 

with an SCR system range from 11 to 20 percent at an incremental cost of $2,051 to 

$2,411 compared to a direct injected turbocharged and downsized internal combustion 

engine. These costs are based on a “bottom up” cost analysis that was performed with 

EPA, which then subtracted the costs of all previous steps on the decision tree prior to 

diesel engines. 

Based on public information and on recent discussions that NHTSA and EPA have had 

with auto manufacturers and aftertreatment device manufacturers, NHTSA has received 

strong indications that LNT systems would probably be used on smaller vehicles while 

the SCR systems would be used on larger vehicles and trucks. The primary reason given 

for this choice is the trade off between the rhodium needed for the LNT and the urea 

injection system needed for SCR. The breakeven point between these two cost factors 

appears to occur around 3.0 liters. Thus, it is believed that it is cheaper to manufacturer 

diesel engines smaller than 3.0 liters with an LNT system, and that conversely, it is 

cheaper to manufacturer diesel engines larger than 3.0 liters with a SCR system. Of 

course, there are other factors that influence a manufacturer’s decision on which system 

to use, but we have used this rule-of thumb for our analysis. 

b. Transmission technologies 

Five-, Six-, Seven- and Eight-Speed Automatic Transmissions 
V-18 

The number of available transmission speeds influences the width of gear ratio spacing 

and overall coverage and, therefore, the degree of transmission ratio optimization 

available under different operating conditions. In general, transmissions can offer a 

greater available degree of engine optimization and can therefore achieve higher fuel 

economy when the number of gears is increased. However, potential gains may be 

reduced by increases in transmission weight and rotating mass. Regardless of possible 

changes to fuel economy standards, manufacturers are increasingly introducing 5- and 6-

speed automatic transmissions on their vehicles. Additionally, some manufacturers are 

introducing 7- and 8-speed automatic transmissions, with 7-speed automatic 

transmissions appearing with increasing frequency. 

Automatic 5-speed Transmissions 

As automatic transmissions have been developed over the years, more forward speeds 

have been added to improve fuel efficiency and performance. Increasing the number of 

available ratios provides the opportunity to optimize engine operation under a wider 

variety of vehicle speeds and load conditions. Also, additional gears allow for overdrive 

ratios (where the output shaft of the transmission is turning at a higher speed than the 

input shaft) which can lower the engine speed at a given road speed (provided the engine 

has sufficient power at the lower rpm point) to reduce pumping losses. However, 

additional gears can add weight, rotating mass, and friction. Nevertheless, manufacturers 

are increasingly adding 5-speed automatic transmissions to replace 3- and 4-speed 

automatic transmissions. 

The 2002 NAS study projected that 5-speed automatic transmissions could incrementally 

reduce fuel consumption by 2 to 3 percent at an incremental cost of $76 to $167. The 

NESCCAF study projected that 5-speed automatic transmissions could incrementally 

reduce fuel consumption by 1 percent at an incremental cost of $140; while the EEA 

report projected that 5-speed automatic transmissions could incrementally reduce fuel 

consumption by 2 to 3 percent at an incremental cost of $130. Confidential manufacturer 

data projected that 5-speed automatic transmissions could incrementally reduce fuel 

consumption by 1 to 6 percent at an incremental cost of from $60 to $281. NHTSA 

believes that the NAS study’s estimates are still valid and estimates that 5-speed 

automatic transmissions could incrementally reduce fuel consumption by 2.5 percent at 

an incremental cost of $76 to $167 (relative to a 4-speed automatic transmission). 

Automatic 6-, 7- and 8-speed Transmissions 

In addition to 5-speed automatic transmissions, manufacturers can also choose to utilize 

6-, 7-, or 8-speed automatic transmissions. Additional ratios allow for further 

optimization of engine operation over a wider range of conditions, but this is subject to 

diminishing returns as the number of speeds increases. As additional planetary gearsets 

are added (which may be necessary in some cases to achieve the higher number of ratios), 

additional weight and friction are introduced. Also, the additional shifting of such a 

transmission can be perceived as bothersome to some consumers, so manufacturers need 
V-19 

to develop strategies for smooth shifts. Some manufacturers are replacing 4-speed 

automatics with 6-speed automatics (there are also increasing numbers of 5-speed 

automatic transmissions that are being replaced by 6-speed automatic transmissions), and 

7-, and 8-speed automatics have entered production, albeit in lower-volume applications. 

The NAS study projected that 6-, 7- or 8-speed transmissions could incrementally reduce 

fuel consumption by 1 to 2 percent at an incremental cost of $70 to $126. Confidential 

manufacturer data projected that 6-, 7- or 8-speed transmissions could incrementally 

reduce fuel consumption by 1 to 3 percent at an incremental cost of $20 to $120. 

However, according to the EEA report, a Lepelletier gear set design provides for 6-

speeds at the same cost as a 5-speed automatic. Based on that analysis, we have estimated 

the cost of a 6-speed automatic to be equivalent to that for a 5-speed automatic. We have 

not developed any estimate costs for 7- or 8-speed transmissions because of the 

diminishing returns in efficiency versus the costs for transmissions beyond 6-speeds. 

NHTSA estimates that 6-, 7-, or 8-speed automatic transmissions could incrementally 

reduce fuel consumption by 0.5 to 2.5 percent at an incremental cost of $0 to $20 

(relative to a 5-speed automatic transmission). We are estimating up to an additional $20 

in costs because we have tried to account for the engineering effort in addition to the 

hardware which we believe the EEA did not and we wanted to capture some of the higher 

costs reported by manufacturers. 

Aggressive Shift Logic 

In operation, an automatic transmission’s controller decides when to upshift or downshift 

based on a variety of inputs such as vehicle speed and throttle position according to 

programmed logic. Aggressive shift logic (ASL) can be employed so that a transmission 

is engineered in such a way as to maximize fuel efficiency by upshifting earlier and 

inhibiting downshifts under some conditions. Through partial lock-up under some 

operating conditions and early lock-up under others, automatic transmissions can achieve 

some reduction in overall fuel consumption. Aggressive shift logic is applicable to all 

vehicle types with automatic transmissions, and since in most cases it would require no 

significant hardware modifications, it can be adopted during vehicle redesign or refresh 

or even in the middle of a vehicle’s product cycle. The application of this technology 

does, however, require a manufacturer to confirm that driveability, durability, and noise, 

vibration, and harshness (NVH) are not significantly degraded. 

The NAS study projected that aggressive shift logic could incrementally reduce fuel 

consumption by 1 to 2 percent at an incremental cost of $0 to $70. Confidential 

manufacturer data projected that aggressive shift logic could incrementally reduce fuel 

consumption by 0.5 to 3 percent at an incremental cost of $18 to $70. The NAS study 

estimates and confidential manufacturer data are within the same ranges, thus NHTSA 

believes that the NAS estimates are still accurate. Thus, NHTSA estimates aggressive 

shift logic could incrementally reduce fuel consumption by 1 to 2 percent at an 

incremental cost of $38, which is approximately the average of the midpoint of the NAS 

cost range and the manufacturer cost range. 
V-20 

Early Torque Converter Lockup 

A torque converter is a fluid coupling located between the engine and transmission in 

vehicles with automatic transmissions and continuously-variable transmissions (CVTs). 

This fluid coupling allows for slip so the engine can run while the vehicle is idling in 

gear, provides for smoothness of the powertrain, and also provides for torque 

multiplication during acceleration. During light acceleration and cruising, this slip causes 

increased fuel consumption, so modern automatic transmissions utilize a clutch in the 

torque converter to lock it and prevent this slippage. Fuel consumption can be further 

reduced by locking up the torque converter early, and/or by using partial-lockup 

strategies to reduce slippage. 

Some torque converters will require upgraded clutch materials to withstand additional 

loading and the slipping conditions during partial lock-up. As with aggressive shift logic, 

confirmation of acceptable driveability, performance, durability and NVH characteristics 

is required to successfully implement this technology. 

The 2002 NAS study did not include any estimates for this technology. The NESCCAF 

study projected that early torque converter lockup could incrementally reduce fuel 

consumption by 0.5 percent at an incremental cost of $0 to $10; while the EEA report 

projected that low-friction lubricants could incrementally reduce fuel consumption by 0.5 

percent at an incremental cost of $5. NHTSA estimates the cost of this technology (i.e., 

the calibration effort) at $30 based in part on NESCCAF and the CBI submissions which 

provided costs with a midpoint of $30. We have used a higher value here than 

NESCCAF and EEA because we have tried to account for the engineering effort in 

addition to the hardware which we believe NESCCAF and EEA did not do and which 

were captured in the manufacturers’ higher costs. 

NHTSA estimates that early torque converter lockup could incrementally reduce fuel 

consumption by approximately 0.5 percent at an incremental cost of approximately $30. 

Automated Shift Manual Transmissions 

An automated manual transmission (AMT) is mechanically similar to a conventional 

transmission, but shifting and launch functions are controlled by the vehicle. There are 

two basic types of AMTs, single-clutch and dual-clutch. A single-clutch AMT is 

essentially a manual transmission with automated clutch and shifting. Because there are 

some shift quality issues with single-clutch designs, dual-clutch AMTs are more 

common. A dual-clutch AMT uses separate clutches for the even-numbered gears and 

odd-numbered gears. In this way, the next expected gear is pre-selected, which allows 

for faster and smoother shifting. 

Overall, AMTs likely offer the greatest potential for fuel consumption reduction among 

the various transmission options presented in this report because they offer the inherently 

lower losses of a manual transmission with the efficiency and shift quality advantages of 

computer control. AMTs offer the lower losses of a manual transmission with the 
V-21 

efficiency advantages of computer control. The lower losses stem from the elimination 

of the conventional lock-up torque converter and a greatly reduced need for high pressure 

hydraulic circuits to hold clutches to maintain gear ratios (in automatic transmissions) or 

hold pulleys in position to maintain gear ratio (in continuously variable transmissions, 

discussed below). However, the lack of a torque converter will affect how the vehicle 

launches from rest, so an AMT will most likely be paired with an engine that offers 

enough torque in the low-RPM range to allow for adequate launch performance. 

An AMT is mechanically similar to a conventional manual transmission, but shifting and 

launch functions are controlled by the vehicle rather than the driver. A switch from a 

conventional automatic transmission with torque converter to an AMT incurs some costs 

but also allows for some cost savings. Savings can be realized through elimination of the 

torque converter which is a very costly part of a traditional automatic transmission, and 

through reduced need for high pressure hydraulic circuits to hold clutches (to maintain 

gear ratios in automatic transmissions) or hold pulleys (to maintain gear ratios in 

Continuously Variable Transmissions). Cost increases would be incurred in the form of 

calibration efforts since transmission calibrations would have to be redone, and the 

addition of a clutch assembly for launce and gear changes. 

The NESCCAF study projected that AMTs could incrementally reduce fuel consumption 

by 5 to 8 percent at an incremental cost of $0 to $280; while the EEA report projected 

that low-friction lubricants could incrementally reduce fuel consumption by 6 to 7 

percent at an incremental cost of $195 to $225. Confidential manufacturer data projected 

that AMTs could incrementally reduce fuel consumption by 2 to 5 percent at an 

incremental cost of $70 to $400. 

Taking all these estimates into consideration, NHTSA estimates that AMTs could 

incrementally reduce fuel consumption by 4.5 to 7.5 percent at an incremental cost of 

approximately $141. We believe that, overall, the hardware associated with an AMT, 

whether single clutch or dual clutch, is no more costly than that for a traditional 

automatic transmission given the savings associated with removal of the torque converter 

and high pressure hydraulic circuits, which is estimated to amount to at least $30. 

Nonetheless, given the need for engineering effort (e.g., calibration and vehicle 

integration work) when transitioning from a traditional automatic to an AMT, we have 

estimated the incremental compliance cost at $141, independent of vehicle class, which is 

the midpoint of the NESCCAF estimates and within the range provided confidential 

manufacturer data. 

Continuously Variable Transmission 

A Continuously Variable Transmission (CVT) is unique in that it does not use gears to 

provide ratios for operation. Unlike manual and automatic transmissions with fixed 

transmission ratios, CVTs provide, within their operating ranges, fully variable 

transmission ratios with an infinite number of gears. This enables even finer optimization 

of the transmission ratio under different operating conditions and, therefore, some 
V-22 

reduction of pumping and engine friction losses. CVTs use either a belt or chain on a 

system of two pulleys. 

The main advantage of a CVT is that the engine can operate at its most efficient point 

more often, since there are no fixed ratios. Also, CVTs often have a wider range of ratios 

than conventional automatic transmissions. 

The most common CVT design uses two V-shaped pulleys connected by a metal belt. 

Each pulley is split in half and a hydraulic actuator moves the pulley halves together or 

apart. This causes the belt to ride on either a larger or smaller diameter section of the 

pulley which changes the effective ratio of the input to the output shafts. 

It is assumed that CVTs will only be used on cars, small SUVs, midsize crossover 

vehicles and minivans because they are currently used mainly in lower-torque 

applications. While a high-torque CVT could be developed for small pickup trucks and 

large pickup trucks and large SUVs, it would likely have to be treated separately in terms 

of effectiveness. We do not see development in the area of high-torque CVTs and 

therefore did not include this type in our analysis. 

The 2002 NAS study projected that CVTs could incrementally reduce fuel consumption 

by 4 to 8 percent at an incremental cost of $140 to $350. The NESCCAF study projected 

that CVTs could incrementally reduce fuel consumption by 4 percent at an incremental 

cost of $210 to $245. Confidential manufacturer data projected that CVTs could 

incrementally reduce fuel consumption by 3 to 9 percent at an incremental cost of $140 to 

$800. These values are incremental to a 4-speed transmission. 

Based on an aggregation of manufacturers’ information, we 

estimate a CVT benefit of about 6% over a 4-speed automatic. This is above the 

NESCCAF value, but in the range of NAS. In reviewing our sources for costs, we have 

determined that the adjusted costs presented in the 2002 NESCCAF study represent the 

best available estimates. Subtracting the estimated fuel consumption reduction and costs 

of replacing a 4-speed automatic transmission with a 5-speed automatic transmission 

results in NHTSA projecting that CVTs could incrementally reduce fuel consumption by 

3.5 percent when compared to a conventional 5-speed automatic transmission at an 

incremental cost of $100 to $139. 

Manual 6-, 7-, and 8-speed Transmissions 

As with automatic transmissions, increasing the number of available ratios in a manual 

transmission can improve fuel economy by allowing the driver to select a ratio that 

optimizes engine operation at a given speed. Typically, this is achieved through adding 

additional overdrive ratios to reduce engine speed (which saves fuel through reduced 

pumping losses). Six-speed manual transmissions have already achieved significant 

market penetration, so manufacturers have considerable experience with them and the 

associated costs. For those vehicles with five-speed manual transmissions, an upgrade to 

a six-speed could incrementally reduce fuel consumption by 0.5 percent. Based on CBI 

submissions, which provided costs with a midpoint of $107, NHTSA estimates that 6-
V-23 

speed manual transmissions could incrementally reduce fuel consumption by 0.5 percent 

when compared to 5-speed automatic transmission at an incremental cost of $107. 

c. Vehicle technologies 

Rolling Resistance Reduction 

Tire characteristics (e.g., materials, construction, and tread design) influence durability, 

traction control, vehicle handling, and comfort. They also influence rolling resistance – 

the 30 frictional losses associated mainly with the energy dissipated in the deformation of 

the tires under load – and therefore, CO2 emissions. This technology is applicable to all 

vehicles, except for body-on-frame light trucks and performance vehicles (described in 

the next section). Based on a 2006 NAS/NRC report, a 10% rolling resistance reduction 

would provide an increase in fuel economy of 1 to 2 percent. The same report estimates a 

$1 per tire cost for low rolling resistance tires. For four tires, our incremental compliance 

cost estimate is $6 per vehicle, independent of vehicle class, although not applicable to 

large trucks. 

Low Drag Brakes 

Low drag brakes reduce the sliding friction of disc brake pads on rotors when the brakes 

are not engaged because the brake shoes are pulled away from the rotating drum. While 

most passenger cars have already adopted this technology, there are indications that this 

technology is still available for body-on-frame trucks. According to confidential 

manufacturer data, low drag brakes could incrementally reduce fuel consumption by 1 

percent at an incremental cost of $85 to $90. NHTSA has adopted these values for its 

analysis. 

Front or Secondary Axle Disconnect for Four-Wheel Drive Systems 

To provide shift-on-the-fly capabilities, many part-time four-wheel drive systems use 

some type of axle disconnect: front axle disconnect in ladder-frame vehicles, and 

secondary (i.e., either front or rear) axle disconnect in unibody vehicles. Front and 

secondary axle disconnect serve two basic purposes. Using front axle disconnect as an 

example, in two-wheel drive mode, the technology disengages the front axle from the 

front driveline so the front wheels do not turn the front driveline at road speed, saving 

wear and tear. Then, when shifting from two- to four-wheel drive “on the fly” (while 

moving), the front axle disconnect couples the front axle to the front differential side gear 

only when the transfer case's synchronizing mechanism has spun the front driveshaft up 

to the same speed as the rear driveshaft. 

Four-wheel drive systems that have axle disconnect typically do not have either manualor automatic-locking hubs. To isolate (for example) the front wheels from the rest of the 

front driveline, front axle disconnects use a sliding sleeve to connect or disconnect an 

axle shaft from the front differential side gear. 
V-24 

This technology has been used by ladder-frame vehicles for some time, but has only 

started to appear on unibody vehicles recently. The incremental costs and benefits of 

applying front axle disconnect differ, depending on the vehicle’s type of construction. 

According to confidential manufacturer data, front axle disconnects for ladder frame 

vehicles could achieve incremental fuel consumption reductions of 1.5 percent at an 

incremental cost of $114, while secondary axle disconnects for unibody vehicles could 

achieve incremental fuel consumption reductions of 1 percent at an incremental cost of 

$676. NHTSA has adopted these estimates for its analysis. 

Aerodynamic Drag Reduction 

A vehicle’s size and shape determine the amount of power needed to push the vehicle 

through the air at different speeds. Changes in vehicle shape or frontal area can therefore 

reduce CO2 emissions. Areas for potential aerodynamic drag improvements include 

skirts, air dams, underbody covers, and more aerodynamic side view mirrors. NHTSA 

and EPA estimate a fleet average of 20% total aerodynamic drag reduction is attainable 

for passenger cars, whereas a fleet average of 10% reduction is more realistic for trucks 

(with a caveat for “high-performance” vehicles, described below). These drag reductions 

equate to increases in fuel economy of 2% and 3% for trucks and cars, respectively. 

These numbers are in agreement with the technical literature and supported by 

confidential manufacturer information. The CBI submittals generally showed the RPE 

associated with these changes at less than $100. NHTSA and EPA estimate that the 

incremental compliance cost to range from $0 to $75, independent of vehicle class. 

Aerodynamic drag reduction technologies are readily available today, although the phasein time required to distribute over a manufacturer’s fleet is relatively long (6 years or so). 

Weight Reduction 

The term weight reduction encompasses a variety of techniques with a variety of costs 

and lead times. These include lighter-weight materials, higher strength materials, 

component redesign, and size matching of components. Lighter-weight materials involve 

using lower density materials in vehicle components, such as replacing steel parts with 

aluminum or plastic. The use of higher strength materials involves the substitution of one 

material for another that possesses higher strength and less weight. An example would 

be using high strength alloy steel versus cold rolled steel. Component redesign is an ongoing process to reduce costs and/or weight of components, while improving 

performance and reliability. An example would be a subsystem replacing multiple 

components and mounting hardware. 

The cost of reducing weight is difficult to determine and is dependent upon the methods 

used. For example, a change in design that reduces weight on a new model may or may 

not save money. On the other hand, material substitution can result in an increase in 

price per application of the technology if more expensive materials are used. 

For purposes of this proposed rule, NHTSA has considered only vehicles weighing 

greater than 5,000 pounds for weight reduction through materials substitution. Provided 
V-25 

that those vehicles remain above 5,000 lbs weight, vehicles may realize up to roughly 2 

percent incremental fuel consumption through materials substitution (corresponding to a 

3 percent reduction in vehicle weight) at incremental costs of $0.75 to $1.25 per pound 

reduced. 

d. Accessory technologies 

Electric Power Steering 

Electric power steering (EPS) is advantageous over hydraulic steering in that it only 

draws power when the wheels are being turned, which is only a small percentage of a 

vehicle’s operating time. EPS may be implemented on many vehicles with a standard 

12V system; however, for heavier vehicles, a 42V system may be required, which adds 

cost and complexity. 

The NAS study projected that a 12V EPS system could incrementally reduce fuel 

consumption by 1.5 to 2.5 percent at an incremental cost of $105 to $150. The 

NESCCAF study projected that a 12V EPS could incrementally reduce fuel consumption 

by 1 percent at an incremental cost of $28 to $56; while the EEA report projected that a 

12V EPS could incrementally reduce fuel consumption by 1.5 to 1.9 percent at an 

incremental cost of $70 to $90. According to confidential manufacturer data, electric 

power steering could achieve incremental fuel consumption reductions of 1.5 to 2.0 

percent at an incremental cost of $118 to $197. 

NHTSA believes that these manufacturer estimates are more accurate and thus estimates 

that a 12V EPS system could incrementally reduce fuel consumption by 1.5 to 2 percent 

at an incremental cost of $118 to $197, independent of vehicle class. 

Engine Accessory Improvement 

The accessories on an engine, like the alternator, coolant, and oil pumps, are traditionally 

driven by the accessory belt. Improving the efficiency or outright electrification (12V) of 

these accessories (in the case of the mechanically driven pumps) would provide an 

opportunity to reduce the accessory loads on the engine. However, the potential for such 

replacement will be greater for vehicles with 42V electrical systems. Some large trucks 

also employ mechanical fans, some of which could also be improved or electrified. 

Additionally, there are now higher efficiency alternators which require less of an 

accessory load to achieve the same power flow to the battery. 

According to the NAS Report engine accessory improvement could achieve incremental 

fuel consumption reductions of 1 to 2 percent at an incremental cost of $124 to $166. 

Confidential manufacturer information is also within these ranges. The NESCCAF study 

estimated a cost of $56, but that estimate included only a high efficiency generator and 

did not include electrification of other accessories. In reviewing our sources for costs, we 

have determined that the adjusted costs presented in the 2002 NAS study, which ranged 

from $124 to $166 - depending on vehicle class – represent the best available estimates. 
V-26 

Based on the NAS study and confidential manufacturer information, NHTSA estimates 

that accessory improvement could incrementally reduce fuel consumption by 1 to 2 

percent at an incremental cost of $124 to $166. 

Forty-Two Volt (42V) Electrical System 

Most vehicles today (aside from hybrids) operate on 12V electrical systems. At higher 

voltages, which appear to be under consideration to meet expected increases in on-board 

electrical demands, the power density of motors, solenoids, and other electrical 

components may increase to the point that new and more efficient systems, such as 

electric power steering, may be feasible. A 42V system can also accommodate an 

integrated starter generator. According to the NAS Report, 42V engine accessory 

improvement could achieve incremental fuel consumption reductions of 1 to 2 percent at 

an incremental cost of $194 to $259. According to confidential manufacturer data, a 42V 

system could achieve incremental fuel consumption reductions of 0 to 4 percent at an 

incremental cost of $62 to $280. 

We believe that the state of 42V technology has evolved to where it is on par with the 

incremental costs and benefits of 12V engine accessory improvement. In reviewing our 

sources, we have determined that the numbers provided in the 2002 NAS study, which 

estimated that engine accessory improvement could achieve incremental fuel 

consumption reductions of 1 to 2 percent at an incremental cost of $124 to $166 - 

depending on vehicle class – represent the best available estimates for both 12V and 42V 

systems. Thus, we are estimating that a 42V electrical system could achieve incremental 

fuel consumption reductions of 1 to 2 percent at an incremental cost of $124 to $166. 

These estimates are independent of vehicle class and exclusive of improvements to the 

efficiencies or electrification of 12V accessories. These estimates are incremental to a 

12V system, regardless of whether the 12V system has improved efficiency or not. 

e. Hybrid technologies 

A hybrid describes a vehicle that combines two or more sources of propulsion energy, 

where one uses a consumable fuel (like gasoline) and one is rechargeable (during 

operation, or by another energy source). Hybrids reduce fuel consumption through three 

major mechanisms: by optimizing the operation of the internal combustion engine 

(through downsizing, or other control techniques) to operate at or near its most efficient 

point more of the time; by recapturing lost braking energy and storing it for later use; and 

by turning off the engine when it is not needed, such as when the vehicle is coasting or 

when stopped. 

Hybrid vehicles utilize some combination of the above three mechanisms to reduce fuel 

consumption. The effectiveness of a hybrid depends on the utilization of the above 

mechanisms and how aggressively they are pursued. Different hybrid concepts utilize 

these mechanisms differently, so they are treated separately in this analysis. Below is a 

discussion of the major hybrid concepts judged to be available for use within the 

timeframe of this rulemaking. 
V-27 

Integrated Starter-Generator with Idle-Off 

Integrated Starter-Generator (ISG) systems are the most basic of hybrid systems and offer 

mainly idle-stop capability. They offer the least power assist and regeneration capability 

of the hybrid approaches, but their low cost and easy adaptability to existing powertrains 

and platforms can make them attractive for some applications. ISG systems operate at 

around 42V and so have smaller electric motors and less battery capacity than other HEV 

designs because of their lower power demand. 

ISG systems replace the conventional belt-driven alternator with a belt-driven, higher 

power starter-alternator. The starter-alternator starts the engine during idle-stop 

operation, but often a conventional 12V gear-reduction starter is retained to ensure coldweather startability. Also, during idle-stop, some functions such as power steering and 

automatic transmission hydraulic pressure are lost with conventional arrangements, so 

electric power steering and an auxiliary transmission pump are added. These components 

are similar to those that would be used in other hybrid designs. An ISG system could be 

capable of providing some launch assist, but it would be limited in comparison to other 

hybrid concepts. According to the NAS Report, an EEA report and confidential 

manufacturer data, ISG systems could achieve incremental fuel consumption reductions 

that range from 5 to 10 percent. 

In addition, when idle-off is used (i.e., the petroleum fuelled engine is shut off during idle 

operation), an electric power steering and auxiliary transmission pump are added to 

provide for functioning of these systems which, in a traditional vehicle, were powered by 

the petroleum engine. The 2002 NAS study estimated the cost of these systems at $210 to 

$350 with a 12 volt electrical system and independent of vehicle class, while the 

NESCCAF study estimated the cost for these systems at $280 with a 12 volt electrical 

system for a small car. The 2002 NAS study estimated the cost of these systems to be 

$210 to $350 with a 12 volt electrical system and independent of vehicle class, while the 

NESCCAF study estimated the cost for these systems of $280 with a 12 volt electrical 

system for a small car. Confidential manufacturer information provides cost estimates for 

ISGs that range from $418 to $800. We believe that the NAS and the NESCCAF 

estimates are still accurate for ISGs with a 12V system. Thus, if you add these cost 

estimates to those we estimated for 42V systems plus associated equipment, which results 

an estimated incremental compliance cost of these systems, including the costs associated 

with upgrading to a 42 volt electrical system of $563 to $600, depending on vehicle class. 

Therefore, NHTSA estimates that ISG systems could achieve incremental fuel 

consumption reductions of 5 to 10 percent at incremental costs of $563 to $600, 

depending on vehicle class (this includes the costs associated with upgrading to a 42 volt 

electrical system). If a 42V system was already applied to a vehicle, the fuel 

consumption reductions and incremental cost for that technology would be subtracted in 

our analysis. 

Integrated Motor Assist (IMA)/Integrated Starter-Alternator-Dampener (ISAD) Hybrid 
V-28 

Honda is the only manufacturer that uses Integrated Motor Assist (IMA), which utilizes a 

thin axial electric motor bolted to the engine’s crankshaft and connected to the 

transmission through a torque converter or clutch. This electric motor acts as both a 

motor for helping to launch the vehicle and a generator for recovering energy while 

slowing down. It also acts as the starter for the engine and the electrical system’s main 

generator. Since it is rigidly fixed to the engine, if the motor turns, the engine must turn 

also, but combustion does not necessarily need to occur. The Civic Hybrid uses cylinder 

deactivation on all four cylinders for decelerations and some cruise conditions. 

The main advantage of the IMA system is it’s relatively low cost and ease of 

adaptability to conventional vehicles and powertrains while providing excellent 

efficiency gains. Packaging space is a concern for the physically longer engine-motortransmission assembly as well as the necessary battery pack, cabling and power 

electronics. According to EPA test data and confidential manufacturer product 

information, the IMA system could achieve incremental fuel consumption reductions of 

3.5 to 8.5 percent.44 NHTSA has adopted these estimates for its analysis. 

The 2002 NAS study did not consider this technology while the NESCCAF study 

estimated the cost for these systems at $2310 to $2940 for a small car and large car, 

respectively. We have used these estimates combined with confidential manufacturer data 

as the basis for our incremental compliance costs of $1636 for the small car and $2274 

for the large car, expressed in 2006 dollars. We have not estimated incremental 

compliance costs for the other vehicle classes because we do not believe those classes 

would use this technology and would, instead, use the hybrid technologies discussed 

below.

2-Mode Hybrids 

GM, DaimlerChrysler, and BMW have formed a joint venture to develop a new HEV 

system based on HEV transmission technology originally developed by GM’s Allison 

Transmission Division for heavy-duty vehicles like city buses. This technology uses an 

adaptation of a conventional stepped-ratio automatic transmission by replacing some of 

the transmission clutches with two electric motors, which makes the transmission act like 

a CVT. Like Toyota’s Power Split design, these motors control the ratio of engine speed 

to vehicle speed. But unlike the Power Split system, clutches allow the motors to be 

bypassed, which improves both the transmission’s torque capacity for heavy-duty 

applications and fuel economy at highway speeds. According to confidential 

manufacturer data, 2-mode hybrids could achieve incremental fuel consumption 

reductions of 25 to 40 percent. NHTSA estimates that 2-mode hybrids could achieve fuel 

reductions of 3.5 percent to 7 percent incremental to an Integrated Motor Assist 

(IMA)/Integrated Starter-Alternator-Dampener (ISAD) Hybrid. 

The 2002 NAS study did not consider this technology, while the NESCCAF study 

estimated the costs to range from $4340 to $5600, depending on vehicle class. These 

 

44 Honda’s cost estimates are protected per Honda’s confidentiality agreement with NHTSA. 
V-29 

estimates are not incremental to an Integrated Motor Assist (IMA)/Integrated StarterAlternator-Dampener (ISAD) Hybrid. To accurately project the cost of 2-mode hybrids 

when they were applied to midsize and large cars we subtracted the estimated costs of an

Integrated Motor Assist (IMA)/Integrated Starter-Alternator-Dampener (ISAD) Hybrid 

We have used the NESCCAF estimates as the basis for our incremental compliance costs 

of $1,501 to $5,127 in 2006 dollars, incremental to an Integrated Motor Assist 

(IMA)/Integrated Starter-Alternator-Dampener (ISAD) Hybrid or an ISG system 

depending on vehicle class.45 We have not estimated incremental compliance costs for 

small cars because we believe that this ISG or IMA/ISAD technology is a better fit for 

small cars.

Power Split Hybrid 

Toyota’s Hybrid Synergy Drive system as used in the Prius is a completely different 

approach than Honda’s IMA system and uses a “Power Split” device in place of a 

conventional transmission. The Power Split system replaces the vehicle’s transmission 

with a single planetary gear and a motor/generator. A second, more powerful 

motor/generator is permanently connected to the vehicle’s final drive and always turns 

with the wheels. The planetary gear splits the engine’s torque between the first 

motor/generator and the drive motor. The first motor/generator uses its engine torque to 

either charge the battery or supply additional power to the drive motor. The speed of the 

first motor/generator determines the relative speed of the engine to the wheels. In this 

way, the planetary gear allows the engine to operate completely independently of vehicle 

speed, much like a CVT.

The Power Split system allows for outstanding fuel economy in city driving. The vehicle 

also avoids the cost of a conventional transmission, replacing it with a much simpler 

single planetary and motor/generator. However, it is less efficient at highway speeds due 

to the requirement that the first motor/generator must be constantly spinning at a 

relatively high speed to maintain the correct ratio. Also, load capacity is limited to the 

first motor/generator’s capacity to resist the reaction torque of the drive train. 

A version of Toyota’s Power Split system is also used in the Lexus RX400h and Toyota 

Highlander sport utility vehicles. This version has more powerful motor/generators to 

handle higher loads and also adds a third motor/generator on the rear axle of four-wheeldrive models. This provides the vehicle with four wheel drive capability and four wheel 

regenerative braking capability. Ford’s CVT system used in the hybrid Escape is another 

version of the Power Split system, but four-wheel-drive models use a conventional 

transfer case and drive shaft to power the rear wheels. 

Other versions of this system are used in the Lexus GS450h and Lexus LS600h luxury 

sedans. These systems have modifications and additional hardware for sustained highspeed operation and/or all-wheel-drive capability. However, the Power Split system isn’t 

planned for usage on full-size trucks and SUVs due to its limited ability to provide the 

 

45 GM’s cost estimates are protected per GM’s confidentiality agreement with NHTSA. 
V-30 

torque needed by these vehicles. It’s anticipated that full-size trucks and SUVs would use 

the 2-mode hybrid system. The 2002 NAS study didn’t consider this technology, while 

the NESCCAF study estimated the incremental costs at to be $3500 prior to any cost 

adjustment. Based on the NESCCAF study and fuel economy test data from EPA’s 

certification database which shows these systems being capable of reducing fuel 

consumption by 25 to 35 percent, NHTSA estimates that Power Split hybrids can achieve 

incremental fuel consumption reductions of 25 to 35 percent over conventionally 

powered vehicles at an incremental cost of $3,700 to $3,850. Because NHTSA applies 

technologies incrementally to the technologies preceding them on our decision trees, the 

incremental fuel consumption reductions for Power Split hybrids are estimated to be 5 to 

6.5 percent incremental to 2-Mode Hybrids (the technology that precedes Power Split 

hybrids on the decision tree), because the technologies applied prior to and including 2-

Mode hybrids are estimated to have incremental fuel consumption reductions of 20 to 

28.5 percent over conventionally powered vehicles. The technologies discussed below 

were not projected for use during the MY 2011 to 2015 timeframes because NHTSA isn’t 

aware that any manufacturer is including these technologies in any vehicle for which we 

have production plans for nor has any manufacturer publicly stated that any of these 

technologies will definitively be included on future products. If NHTSA receives such 

information regarding any technology(ies), it will revisit this decision for the final rule. 

NHTSA is including its discussion of these technologies and their estimated costs and 

fuel consumption reductions as a reference for commenters and in anticipation of their 

possible inclusion in the final rule. 

Variable Compression Ratio 

A spark-ignited engine’s specific power is limited by the engine’s compression ratio, 

which is, in turn, currently limited by the engine’s susceptibility to knock, particularly 

under high load conditions. Engines with variable compression ratio (VCR) improve fuel 

economy by the use of higher compression ratios at lower loads and lower compression 

ratios under higher loads. The NAS Report projected that VCR could incrementally 

reduce fuel consumption by 2 to 6 percent over 4-valve VVT at an incremental cost of 

$218 to $510. NHTSA has no information which suggests that VCR will be included on 

any vehicles during the MY 2011-2015 timeframe, thus NHTSA does not use this 

technology in its analysis. Additionally, no updates to these estimates were sought. 

Lean-Burn Gasoline Direct Injection Technology 

One way to improve dramatically an engine’s thermodynamic efficiency is by operating 

at a lean air-fuel mixture (excess air). Fuel system improvements, changes in combustion 

chamber design and repositioning of the injectors have allowed for better air/fuel mixing 

and combustion efficiency. There is currently a shift from wall-guided injection to spray 

guided injection, which improves injection precision and targeting towards the spark 

plug, increasing lean combustion stability. Combined with advances in NOx aftertreatment, lean-burn GDI engines may be a possibility in North America. 
V-31 

However, a key technical requirement for lean-burn GDI engines to meet EPA’s Tier 2 

NOx emissions levels is the availability of low-sulfur gasoline, which is projected to be 

unavailable during MY 2011 – 2015. 

According to the NESCCAF report and confidential manufacturer data NHTSA estimates 

that lean-burn GDI engines could incrementally reduce fuel consumption from 9 to 16 

percent at an incremental cost of $500 to $750 compared to a port-fueled (stoichiometric) 

engine. NHTSA did not project the use of this technology during the time frame covered 

by this proposal, due to large uncertainties surrounding the availability of low-sulfur 

gasoline. Nonetheless, we have estimated the incremental compliance cost for these 

systems at $750, independent of vehicle class, and incremental to a stoichiometric GDI 

engine. 

Homogeneous Charge Compression Ignition 

Homogeneous charge compression ignition (HCCI), also referred to as controlled auto 

ignition (CAI), is an alternate engine operating mode that does not rely on a spark event 

to initiate combustion. The principles are more closely aligned with a diesel combustion 

cycle, in which the compressed charge exceeds a temperature and pressure necessary for 

spontaneous ignition. The resulting burn is much shorter in duration with higher thermal 

efficiency. 

An HCCI engine has inherent advantages in its overall efficiency for several reasons. An 

extremely lean fuel/air charge increases thermodynamic efficiency. Shorter combustion 

times and higher EGR tolerance permit very high compression ratios (which also increase 

thermodynamic efficiency). Additionally, pumping losses are reduced because the 

engine can run unthrottled. 

However, due to the nature of its combustion process, HCCI is difficult to control, 

requiring in-cylinder pressure sensors and very fast engine control logic to optimize 

combustion timing, especially considering the variable nature of operating conditions 

seen in a vehicle. To be used in a commercially acceptable vehicle application, an HCCIequipped engine would most likely be “dual-mode,” in which HCCI operation is 

complemented with a traditional SI combustion process at idle and at higher loads and 

speeds. 

Until recently, HCCI technology was considered to still be in the research phase. 

However, several manufacturers have made public statements about the viability of 

incorporating HCCI into production vehicles over the next 10 years. The NESCCAF 

study estimated the cost to range from $560 to $840, depending on vehicle class, 

including the costs for a stoichiometric GDI system with DVVL. We have based our 

estimated incremental compliance cost on the NESCCAF estimates and, after subtracting 

out the estimated incremental cost for a stoichiometric GDI system with DVVL, we 

estimate the incremental cost for HCCI to be from $263 to $685, depending on vehicle 

class. This estimated incremental compliance cost is incremental to a stoichiometric GDI 

engine. 
V-32 

Advanced CVT 

Advanced CVTs have the ability to deliver higher torques than existing CVTs and have 

the potential for broader market penetration. These new designs incorporate toroidal 

friction elements or cone-and-ring assemblies with varying diameters. According to the 

NAS Report, advanced CVT could incrementally reduce fuel consumption by up to 2 

percent at an incremental cost of $364 to $874. NHTSA has no information which 

suggests that VCR will be included on any vehicles during the MY 2011-2015 timeframe, 

thus NHTSA does not use this technology in its analysis. Additionally, no updates to 

these estimates were sought. 

Plug-in Hybrids 

Plug-In Hybrid Electric Vehicles (PHEVs) are very similar to hybrid electric vehicles, 

but with three significant functional differences. The first is the addition of a means to 

charge the battery pack from an outside source of electricity (usually the electric grid). 

Second, a PHEV would have a larger battery pack with more energy storage, and a 

greater capability to be discharged. Finally, a PHEV would have a control system that 

allows the battery pack to be significantly depleted during normal operation. 

Deriving some of their propulsion energy from the electric grid provides several 

advantages for PHEVs. PHEVs offer a significant opportunity to replace petroleum used 

for transportation energy with domestically-produced electricity. The reduction in 

petroleum usage does, of course, depend on the amount of electric drive the vehicle is 

capable of under its duty cycle. 

The fuel consumption reduction potential of PHEVs depends on many factors, the most 

important being the electrical capacity designed into the battery pack. To estimate the 

fuel consumption reduction potential of PHEVs, EPA has developed an in-house vehicle 

energy model (PEREGRIN) which is based on the PERE (Physical Emission Rate 

Estimator) physics-based model used as a fuel consumption input for EPA’s 

MOVES mobile source emissions modelB. 

EPA modeled the PHEV small car, large car, minivan and small trucks using parameters 

from a midsize car similar to today’s hybrids and scaled to each vehicle’s weight. The 

large truck PHEV was modeled separately assuming very little engine downsizing. Each 

PHEV was assumed to have enough battery capacity for a 20-mile-equivalent all-electric 

range and a power requirement to provide similar performance to a hybrid vehicle. A 

twenty mile range was selected because it offers a good compromise for vehicle 

performance, weight, battery packaging and cost. 

To calculate the total energy use of a PHEV, a vehicle can be thought of as 

operating in two distinct modes, electric (EV) mode, and hybrid (HEV) mode. The 

energy consumed during EV operation can be accounted for and calculated in terms of 

gasoline-equivalent MPG by using 10CFR474, Electric and Hybrid Vehicle Research, 

Development, and Demonstration Program; Petroleum-Equivalent Fuel Economy 
V-33 

Calculation. The EV mode fuel economy can then be combined with the HEV mode fuel 

economy using the Utility Factor calculation in SAE J1711 to determine a total MPG 

value for the vehicle. Calculating a total fuel consumption reduction based on model 

outputs, gasoline-equivalent calculations, and the Utility Factor calculations, results in a 

28% fuel consumption reduction for small cars, large cars, minivans, and small trucks 

and a 31% fuel consumption reduction for large trucks. 

The fuel consumption reduction potential of PHEVs will vary based on the electrical 

capacity designed into the battery pack. Assuming a 20-mile “all-electric range” design, 

a PHEV might incrementally reduce fuel consumption by 28 to 31 percent.46 Based on 

discussions with EPA, we have estimated the incremental cost of PHEVs to be from 

$4500 to $10200, depending on vehicle class. 

NHTSA is aware that manufacturers have made public statements about their intent to 

produce PHEVs during the MY 2011 – 2015 timeframe. However, NHTSA has received 

no information from these manufacturers that provides all the specifications and 

production data that is necessary for NHTSA to include these vehicles in this analysis. 

NHTSA hopes to receive complete product plan information from these manufacturers 

concerning any PHEVs that they plan on producing during the MY 2011- 2015 

timeframe. 

NHTSA would like to note that if it receives new and/or updated information from 

manufacturers regarding the likelihood of PHEV production during the MY 2011 to 2015 

timeframe, it will make every effort to include PHEVs as a technology in its final rule. 

To enable the possible inclusion of PHEVs as a technology, NHTSA would also have to 

configure the Volpe model to account for the estimated source(s) that would supply the 

electricity for electrical grid charging of the battery. Work has started on this effort, but 

has not yet been completed. 

Additionally, NHTSA is unaware of the existence of any batteries that are deemed 

acceptable for the performance characteristics necessary for a plug-in hybrid. Therefore, 

although we discuss them here, the model does not currently apply them. 

The tables below summarize for each of the 10 classes of vehicles the cost and 

effectiveness assumptions used in this rulemaking as well as the year of availability of 

each technology. The agency seeks comments on our assumptions and the cost and 

effectiveness estimates provided. 

 

46 This estimate is based on the EPA test cycle. We are unable to provide cost estimates for PHEV 

technology due to the great amount of uncertainty surrounding the chemistry, safety and performance 

requirements of the appropriate battery technology that would be used. 
V-34 

Table V-1 Technology Cost Estimates 

Technologies Vehicle Technology Incremental Retail Price Equivalent per Vehicle ($) by Vehic

Subcompact 

Car 

Compact 

Car 

Midsize 

Car 

Large Car Small 

Pickup 

Small 

SUV Minivan Midsize SUV 

 Low friction lubricants – incremental to base engine 3 3 3 3 3 3 3 3  Engine friction reduction – incremental to base engine 0-84 0-84 0-126 0-126 0-126 0-126 0-126 0-126  Overhead Cam Branch 

VVT – intake cam 

phasing 59 59 119 119 119 119 119 119 

VVT – coupled cam 

phasing 59 59 119 119 119 119 119 119 

VVT – dual cam phasing 89 89 209 209 209 209 209 209 Cylinder deactivation n.a. n.a. 203 203 203 203 203 203 Discrete VVLT 169 169 246 246 246 246 246 246 Continuous VVLT 254 254 466 466 466 466 466 466 

 Overhead Valve Branch 

Cylinder deactivation n.a. n.a. 203 203 203 203 203 203 VVT – coupled cam phasing 

59 59 59 59 59 59 59 59 

Discrete VVLT 169 169 246 246 246 246 246 246 Continuous VVLT (includes conversion to Overhead Cam) 599 599 1262 1262 1262 1262 1262 1262 

 Camless valvetrain (electromagnetic) 336-673 336-673 336-673 336-673 336-673 336-673 336-673 336-673  GDI – stoichiometric 122-420 122-420 204-525 204-525 204-525 204-525 204-525 204-525  GDI – lean burn 750 750 750 750 750 750 750 750  Gasoline HCCI dual-mode 263 263 390 390 390 390 390 390  Turbocharge & downsize 690 690 120 120 120 120 120 120  Diesel – Lean NOx trap 1586 1586  Diesel – urea SCR 2051 2051 2411 2411 2126 2411  Aggressive shift logic 38 38 38 38 38 38 38 38  Early torque converter lockup 30 30 30 30 30 30 30 30  5-speed automatic 76-167 76-167 76-167 76-167 76-167 76-167 76-167 76-167  6-speed automatic 76-187 76-187 76-187 76-187 76-187 76-187 76-187 76-187  6-speed AMT 141 141 141 141 141 141 141 141 
V-35 

 6-speed manual 107 107 107 107 107 107 107 107  CVT 100 100 139 139 n.a. 139 139 139 
V-36 

 Stop-Start with 42 volt system 563 563 600 600 600 600 600 600  IMA/ISA/BSG (includes engine downsize) 1636 1636 2274 2274 n.a n.a n.a n.a  2-Mode hybrid electric vehicle n.a n.a 4655 4655 4655 4655 4655 4655  Power-split hybrid electric vehicle (P-S HEV) 3700-3850 3700-3850 3700-3850 3700-3850 3700-3850 3700-3850 3700-3850 3700-385 Plug-in hybrid electric vehicle (PHEV) 4500 4500 6750 6750 6750 6750 6750 6750  Improved high efficiency 

alternator & electrification of accessories (12 volt) 

124-166 124-166 124-166 124-166 124-166 124-166 124-166 124-166 

 Electric power steering (12 or 42 volt) 118-197 118-197 118-197 118-197 118-197 118-197 118-197 118-197  Improved high efficiency alternator & electrification of accessories (42 volt) 

124-166 124-166 124-166 124-166 124-166 124-166 124-166 124-166 

 Aero drag reduction (20% on cars, 10% on trucks) 0-75 0-75 0-75 0-75 0-75 0-75 0-75 0-75  Low rolling resistance tires (10%) 6 6 6 6 6 6 6 6  Low drag brakes (ladder frame only) 87 87 87  Secondary axle disconnect (unibody only) 676 676 676 676 676 676 676 676  Front axle disconnect (ladder frame only) 114 114 114  Weight reduction (1%) – above 5,000 lbs only  Weight reduction (2%) – incremental to 1%  Weight reduction (3%) – incremental to 2% 

Subcompact 

Car 

Compact 

Car 

Midsize 

Car 

Large Car Small 

Pickup 

Small 

SUV Minivan Midsize SUV 
V-37 

Table V-2: Technology Percent Effectiveness Estimates

Technologies Vehicle Technology Incremental Fuel Consumption Reduction (%) by Vehicle 

Subcompact 

Car 

Compact 

Car 

Midsize 

Car 

Large 

Car 

Small 

Pickup 

Small 

SUV Minivan Midsize SUV 

 Low friction lubricants – incremental to base engine 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  Engine friction reduction – incremental to base engine 1-3 1-3 1-3 1-3 1-3 1-3 1-3 1-3  Overhead Cam Branch VVT – intake cam phasing 2 2 1 1 1 1 1 1 VVT – coupled cam phasing 1 1 3 3 2 2 1 1 VVT – dual cam phasing 1 1 3 3 1 1 1 1 Cylinder deactivation n/a n/a 4.5 4.5 4.5 4.5 4.5 4.5 Discrete VVLT 3 3 1.5 1.5 1.5 1.5 0.5 0.5 Continuous VVLT 4 4 3.5 3.5 2.5 2.5 1.5 1.5  Overhead Valve Branch Cylinder deactivation n/a n/a 6 6 6 6 6 6 VVT – coupled cam phasing 3 3 2.5 2.5 1.5 1.5 0.5 0.5 Discrete VVLT 1.5 1.5 1.5 1.5 1.5 1.5 0.5 0.5 Continuous VVLT (includes conversion to Overhead Cam) 

2.5 2.5 3.5 3.5 2.5 2.5 1.5 1.5 

 Camless valvetrain (electromagnetic) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5  GDI – stoichiometric 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2  GDI – lean burn - - - - - - - -  Gasoline HCCI dual-mode 10-12 10-12 10-12 10-12 10-12 10-12 10-12 10-12  Turbocharge & Downsize 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5 5.0 – 7.5  Diesel – Lean NOx trap 11.5 11.5 n/a n/a n/a n/a n/a n/a  Diesel – urea SCR n/a n/a 15.5 15.5 15.5 15.5 15.5 15.5  Aggressive shift logic 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2  Early torque converter lockup 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  5-speed automatic 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5  6-speed automatic 0.5-2.5 0.5-2.5 0.5-2.5 0.5-2.5 0.5-2.5 0.5-2.5 0.5-2.5 0.5-2.5  6-speed AMT 4.5-7.5 4.5-7.5 4.5-7.5 4.5-7.5 4.5-7.5 4.5-7.5 4.5-7.5 4.5-7.5  6-speed manual 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5  CVT 3.5 3.5 3.5 3.5 n/a 3.5 3.5 3.5 
V-38 

 Stop-Start with 42 volt system 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5  IMA/ISA/BSG (includes engine downsize) 8.5 8.5 3.5 3.5 n/a n/a n/a n/a  2-Mode hybrid electric vehicle n/a n/a 3.5 3.5 7 7 7 7  Power-split hybrid electric vehicle (P-S HEV) 5 5 6.5 6.5 6.5 6.5 6.5 6.5  Plug-in hybrid electric vehicle (PHEV) 28 28 28 28 28 28 28 28  Improved high efficiency alternator & electrification of accessories (12 volt) 

1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 

 Electric power steering (12 or 42 volt) 1.5 1.5 1.5-2 1.5-2 2 2 2 2  Improved high efficiency alternator & electrification of accessories (42 volt) 

1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2 

 Aero drag reduction (20% on cars, 10% on trucks) 3 3 3 3 2 2 3 3  Low rolling resistance tires (10%) 1-2 1-2 1-2 1-2 1-2 1-2 1-2 1-2  Low drag brakes (ladder frame only) n/a n/a n/a n/a 1 1 n/a n/a  Secondary axle disconnect (unibody only) 1 1 1 1 1 1 1 1  Front axle disconnect (ladder frame only) n/a n/a n/a n/a 1.5 1.5 n/a n/a  Weight reduction (1%) – above 5,000 lbs only n/a n/a n/a n/a n/a n/a n/a n/a  Weight reduction (2%) – incremental to 1% n/a n/a n/a n/a n/a n/a n/a n/a  Weight reduction (3%) – incremental to 2% n/a n/a n/a n/a n/a n/a n/a n/a 

Sub 

compact 

Car 

Compact 

Car 

Midsize 

Car 

Large 

Car 

Small 

Pickup 

Small 

SUV Minivan Midsize SUV 
V-39 

Table V-3: Year of Availability 

Technologies Year of 

Availability 

 Low friction lubricants – incremental to base engine Present 

 Engine friction reduction – incremental to base engine Present 

 Overhead Cam Branch 

VVT – intake cam phasing Present 

VVT – coupled cam phasing Present 

VVT – dual cam phasing Present 

Cylinder deactivation Present 

Discrete VVLT Present 

Continuous VVLT Present 

 Overhead Valve Branch 

Cylinder deactivation Present 

VVT – coupled cam phasing Present 

Discrete VVLT Present 

Continuous VVLT (includes conversion to Overhead Cam) Present 

 Camless valvetrain (electromagnetic) 2020 

 GDI – stoichiometric Present 

 GDI – lean burn 2020 

 Gasoline HCCI dual-mode 2016 

 Turbocharging & Downsizing 2010 

 Diesel – Lean NOx trap 2010 

 Diesel – urea SCR 2010 

 Aggressive shift logic Present 

 Early torque converter lockup Present 

 5-speed automatic Present 

 6-speed automatic Present 

 6-speed AMT 2010 

 6-speed manual Present 

 CVT Present 

 Stop-Start with 42 volt system 2014 

 IMA/ISA/BSG (includes engine downsize) 2014 

 2-Mode hybrid electric vehicle 2014 

 Power-split hybrid electric vehicle (P-S HEV) 2014 

 Full-Series hydraulic hybrid NA 

 Plug-in hybrid electric vehicle (PHEV) NA 

 Full electric vehicle (EV) NA 

 Improved high efficiency alternator & electrification of accessories (12 volt) Present 

 Electric power steering (12 or 42 volt) Present 

 Improved high efficiency alternator & electrification of accessories (42 volt) Present 

 Aero drag reduction (20% on cars, 10% on trucks) Present 

 Low rolling resistance tires (10%) Present 

 Low drag brakes (ladder frame only) Present 

 Secondary axle disconnect (unibody only) 2012 

 Front axle disconnect (ladder frame only) Present 

 Weight reduction (1%) – above 6000 lbs only Present 

 Weight reduction (2%) – incremental to 1% Present 

 Weight reduction (3%) – incremental to 2% Present 
V-40 

C. Technology synergies

When two or more technologies are added to a particular vehicle model to improve its fuel 

efficiency, the resultant fuel consumption reduction may sometimes be higher or lower than the 

product of the individual effectiveness values for those items. This may occur because one or 

more technologies applied to the same vehicle partially address the same source or sources of 

engine or vehicle losses. Alternately, this effect may be seen when one technology shifts the 

engine operating points, and therefore increases or reduces the fuel consumption reduction 

achieved by another technology or set of technologies. The difference between the observed fuel 

consumption reduction associated with a set of technologies and the product of the individual 

effectiveness values in that set is sometimes referred to as a “synergy.” Synergies may be 

positive (increased fuel consumption reduction compared to the product of the individual effects) 

or negative (decreased fuel consumption reduction). 

The NAS committee which authored the 2002 Report was aware of technology synergies and 

considered criticisms as part of the peer-review process that its analysis was “judgmentsimplified,” but concluded overall that its approach was “sufficiently rigorous” for purposes of 

the report.47 After examining its analysis again, the committee stated that “...the path 1 and path 

2 estimate average fuel consumption improvements ... appear quite reasonable, although the 

uncertainty in the analysis grows as more technology features are considered.”48 In essence, as 

more technology features are considered, the features are more likely to overlap and result in 

synergies. Because NAS did not expect vehicle manufacturers to reach “path 3” in the 

timeframe considered, it did not concern itself deeply with the effect of technology synergies in 

its analysis. 

NHTSA’s rulemaking regarding CAFE standards for MY 2008-MY 2011 light trucks made 

significant use of NAS’ “path 2” estimates of the effectiveness and cost of available 

technologies. In part because its analysis did not extend to the more aggressive “path 3,” the 

agency concluded that the NAS-based multiplicative approach it followed when aggregating 

these technologies was reasonable. In contrast, the agency’s current proposal is based on an 

analysis that includes a broader range of technologies than was considered by NAS in 2001 and 

2002. Also, the extent to which technologies are included in the current analysis is more 

consistent with NAS’ prior “path 3” approach. Therefore, the agency’s current analysis uses 

estimated “synergies” to address the uncertainties mentioned in the 2002 NAS report. 

The Volpe model has been modified to estimate the interactions of technologies using estimates 

of incremental synergies associated with a number of technology pairs identified by NHTSA, 

Volpe Center, and EPA staff. The use of discrete technology pair incremental synergies is 

similar to that in DOE’s National Energy Modeling System (NEMS).49 Inputs to the Volpe 

model incorporate NEMS-identified pairs, as well as additional pairs from the set of technologies 

considered in the Volpe model. However, to maintain an approach that was consistent with the 

 

47 NAS Report, p. 151. 

48 Id.

49 U.S. Department of Energy, Energy Information Administration, Transportation Sector Module of the 

National Energy Modeling System: Model Documentation 2007, May 2007, Washington, DC, DOE/EIAM070(2007), pp. 29-30. 
V-41 

technology sequencing developed by NHTSA, Volpe Center, and EPA staff, new incremental 

synergy estimates for all pairs were obtained from a first-order “lumped parameter” analysis tool 

created by EPA.50 Results of this analysis were generally consistent with those of full-scale 

vehicle simulation modeling performed by Ricardo, Inc.51 NHTSA’s analysis applies these 

incremental synergy values, obtained from the tool using baseline passenger car engine and 

vehicle inputs, to all vehicle classes. 

Incremental synergy values are specified in Volpe model input files in two ways: as part of the 

incremental effectiveness values table (same path technologies) and in a separate incremental 

synergies table (separate path technologies). In the case of same path technologies, each 

technology's incremental effectiveness value was obtained from the technical literature and 

manufacturers’ submitted information, and then the sum of all incremental synergies associated 

with that technology and each technology located higher on the same path was subtracted to 

determine the incremental effectiveness. For example, all engine technologies take into account 

incremental synergy factors of preceding engine technologies; all transmission technologies take 

into account incremental synergy factors of preceding transmission technologies. These factors 

are expressed in the fuel consumption improvement factors in the input files used by the Volpe 

model. 

For applying incremental synergy factors in separate path technologies, the Volpe model uses an 

input table which lists technology pairings and incremental synergy factors associated with those 

pairings, most of which are between engine technologies and transmission technologies. When a 

technology is applied to a vehicle by the Volpe model, all instances of that technology in the 

incremental synergy table which match technologies already applied to the vehicle (either preexisting or previously applied by the Volpe model) are summed and applied to the fuel 

consumption improvement factor of the technology being applied. When the Volpe model 

applies incremental synergies, the fuel consumption improvement factors cannot be reduced 

below zero. 

Incremental synergy values were calculated assuming the prior application (implying succession 

in some cases) of all technologies located higher along both paths than the pair considered. This 

is usually a true reflection of a given vehicle's equipment at any point in the model run and thus 

the method is expected to produce reasonable results in most cases. 

NHTSA considered other methods for estimating interactions between technologies. For 

example, the agency has considered integrating detailed simulation of individual vehicles’ 

performance into the Volpe model.52 However, while application of such simulation techniques 

could provide a useful source of information when developing inputs to the Volpe model, the 

 

50 This tool is a simple spreadsheet model that represents energy consumption in terns of average performance over 

the fuel economy test procedure, rather than explicitly analyzing specific drive cycles. The tool begins with an 

apportionment of fuel consumption across several loss mechanisms, and accounts for the average extent to which 

different technologies affect these loss mechanisms 

51 EPA contracted with Ricardo, Inc. (an independent consulting firm) to study the potential effectiveness of carbon 

dioxide-reducing (and thus, fuel economy-improving) vehicle technologies. The Ricardo study is available in the 

docket for this NPRM. 

52 In other words, having the Volpe model run a full vehicle simulation every time the Volpe model is evaluating the 

potential effect of applying a specific technology to a specific vehicle model. 
V-42 

agency believes that applying detailed simulation when analyzing the entire fleet of future 

vehicles is neither necessary nor feasible. NHTSA is charged with setting standards at the 

maximum feasible level. To understand the potential impacts of its standards, the agency 

analyzes entire fleets of vehicles expected to be produced in the future. Although some expected 

engineering characteristics of these vehicles are available, the level of detail needed for full 

vehicle simulation—a level of detail that would be important if NHTSA were actually designing 

vehicles—is not available. 

As another possible alternative to using “synergy” factors, NHTSA has also considered 

modifying the Volpe model to accept as inputs different measures of efficiency for each engine, 

transmission, and vehicle model in the product plans. For instance, manufacturers could provide 

estimates of mechanical and drivetrain efficiencies. Mechanical efficiency (usually between 70 

and 90 percent) gives an estimate of the amount of fuel consumed by engine friction and 

pumping losses. Drivetrain efficiency (usually between 80 and 90 percent) gives an estimate of 

the amount of fuel consumed by parasitic loads and gearbox friction. From these efficiencies 

along with other inputs such as compression ratio, aerodynamic drag, rolling resistance, and 

vehicle mass, the model could estimate the fuel consumption associated with each loss 

mechanism and enforce a maximum fuel consumption reduction for each vehicle model based on 

those estimates and the technologies applied. Like the use of incremental synergies, this method 

could help the model avoid double counting fuel consumption benefits when applying multiple 

technologies to the same vehicle model.53 The agency believes that this approach, like the use of 

“synergy” factors currently used by the Volpe model, could conceivably provide a means of 

addressing uncertainty in fuel consumption estimation within the context of CAFE analysis. 

However, the agency is not confident that model-by-model estimates of baseline fuel 

consumption partitioning would be available. Also, partitioned estimates of the effects of all the 

technologies considered in the analysis of this proposal were not available. If both of these 

concerns could be addressed, NHTSA believes it would be possible to implement partitioned 

accounting of fuel consumption. However, the agency is unsure whether and, if so, to what 

extent doing so would represent an improvement over our current approach of using incremental 

synergy factors. 

The agency solicits comments on its use of incremental synergy factors to address uncertainty in 

the estimation of the extent to which fuel consumption is reduced by applying technologies. In 

particular, the agency solicits comment on (a) the values of the factors the agency has applied, 

(b) possible variations across the ten categories of vehicles the agency has considered, and (c) 

additional technology pairs that may involve such interactions. The proposal of any additional 

methodologies, such as prototyping and testing, full vehicle simulation, or partitioned 

accounting, should address information and resource requirements, particularly as related to the 

analysis of entire fleets of future vehicles expected to be produced through MY 2015. 

4. Technology cost learning curve 

 

53 This approach was proposed in a paper criticizing NAS’ approach to synergies in the 2001-02 peer-review process 

for the NAS Report. See Patton, et al., “Aggregating Technologies for Reduced Fuel Consumption: A Review of 

the Technical Content in the 2002 National Research Council Report on CAFE”, SAE 2002-01-0628, March 2002. 
V-43 

In past rulemaking analyses, NHTSA did not explicitly account for the cost reductions a 

manufacturer may realize through learning achieved from experience in actually applying a 

given technology. NHTSA understood technology cost-estimates to reflect already the full 

learning costs of technology. EPA felt that for some of the newer, emerging technologies, cost 

estimates did not reflect the full impact of learning. NHTSA tentatively agreed, but is seeking 

comment on the impact of learning on cost and the production volumes where it occurs. NHTSA 

has modified its previous approach in this rulemaking for that reason. In this rulemaking we have 

included a learning factor for some of the technologies. The “learning curve” describes the 

reduction in unit incremental production costs as a function of accumulated production volume 

and small redesigns that reduce costs. 

NHTSA implemented technology learning curves by using three parameters: (1) the initial 

production volume that must be reached before cost reductions begin to be realized (referred to 

as “threshold volume”); (2) the percent reduction in average unit cost that results from each 

successive doubling of cumulative production volume (usually referred to as the “learning rate”); 

and (3) the initial cost of the technology. Section V below describing the Volpe model contains 

additional information on learning curve functions. 

Figure 2 illustrates a learning curve for a vehicle technology with an initial average unit cost of 

$100 and a learning rate of approximately 20 percent. In this hypothetical example, the initial 

production volume before cost reductions begin to be realized is set at 12,000 units and the 

production volume at the cost floor is set at roughly 50,000 units with a cost of $64. 

Figure 2. Typical Experience Curve 

Most studies of the effect of the learning curve on production costs appear to assume that cost 

reductions begin only after some initial volume threshold has been reached, but not all of these 

studies specify what this threshold volume is. The rate at which costs decline beyond the initial 

threshold is usually expressed as the percent reduction in average unit cost that results from each 

successive doubling of cumulative production volume, sometimes referred to as the learning 

rate. Many estimates of learning experience curves do not specify a cumulative production 

volume beyond which cost reductions no longer occur, instead depending on the asymptotic 
V-44 

behavior of the above expression of (CQ) for learning rates below 100 percent to establish a floor 

on costs. 

For this analysis, NHTSA has applied learning curve cost reductions on a manufacturer-specific 

basis, and has assumed that learning-based reductions in technology costs occur at the point that 

a manufacturer applies the given technology to 25,000 cars or trucks, and are repeated a second 

time as it produces another 25,000 cars or trucks for the second learning step (car and truck 

volumes are treated separately for determining these sales volumes). The volumes chosen 

represent our best estimate for where learning would occur. As such, we believe that these 

estimates are better suited to this analysis than a more general approach of a single number for 

the learning curve factor, because each manufacturer would be implementing technologies at its 

own pace in this rule, rather than assuming that all manufacturers implement identical 

technology at the same time. NHTSA is aware that some of the cost estimates that is has relied 

upon were derived from suppliers and has added multipliers so that these costs are reflective of 

what manufacturers would pay for this technology. NHTSA seeks comments on the estimated 

level of price markups that manufacturers pay for technologies purchased from suppliers and 

whether different learning curves should be applied to those types of technologies. 

Ideally, we would know the development production cycle and maturity level for each 

technology so that we could calculate learning curves precisely. Without that knowledge, we 

have to use engineering judgment. After having produced 25,000 cars or trucks with a specific 

part or system, we believe that sufficient learning will have taken place such that costs will be 

lower by 20 percent for some technologies and 10 percent for others. After another 25,000 units, 

its expected that, for some technologies, such as 6-speed AMTs, that another cost reduction will 

have been realized. 

For each of the technologies, we have considered whether we could project future cost 

reductions due to manufacturer learning. In making this determination, we considered whether 

or not the technology was in wide-spread use today or expected to be by the model year 2011-

2012 time frame, in which case no future learning curve would apply because the technology 

would already be in wide-spread production by the automotive industry by that timeframe, e.g., 

on the order of multi-millions of units per year. (Examples of these include 5-speed automatic 

transmissions and intake-cam phasing variable valve timing. These technologies have been in 

production for light-duty vehicles for more than 10 years.) In addition, we carefully considered 

the underlying source data for our cost estimates. If the source data specifically stated that 

manufacturer cost reduction from future learning would occur, we took that information into 

account in determining whether we would apply manufacturer learning in our cost projections. 

Thus, for many of the technologies, we have not applied any future cost reduction learning curve. 

However, there are a number of technologies which are not yet in mass production for which we 

have applied a learning curve. As indicated in Table 7 below, we have applied the learning 

curve beginning in MY 2011 to one set of technologies, and for a number of additional 

technologies we did not apply manufacturer learning until MY 2014. The distinction between 

MYs 2011 and 2014 is due to our source data for our cost estimates. For those technologies 

where we have applied manufacturer learning in MY 2011, the source of our cost estimate did 
V-45 

not rely on manufacturer learning to develop the initial cost estimate we have used – therefore 

we apply the manufacturer learning methodology beginning in MY 2011. 

Table 7. Learning Curve Application to Technologies 

Technology First Year 

of 

Application 

Learning

Factor

Overhead Cam Branch 

Cylinder deactivation 2014 20% 

Continuous VVLT 2014 20% 

Camless valvetrain (electromagnetic) 2011 20% 

GDI – lean burn 2011 20% 

Gasoline HCCI dual-mode 2011 20% 

Turbocharging & downsizing 2014 20% 

Diesel – Lean NOx trap* 2011 10% 

Diesel – urea SCR* 2011 10% 

6-speed AMT 2011 20% 

Stop-Start with 42 volt system 2014 20% 

IMA/ISA/BSG (includes engine downsize) 2014 20% 

2-Mode hybrid electric vehicle 2014 20% 

Power-split hybrid electric vehicle (P-S HEV) 2014 20% 

Plug-in hybrid electric vehicle (PHEV) 2011 20% 

Improved high efficiency alternator & electrification of accessories (42 

volt) 2011 20% 

Secondary axle disconnect (unibody only) 2011 20% 

Weight reduction (1%) – above 6000 lbs only 2011 20% 

Weight reduction (2%) – incremental to 1% 2011 20% 

Weight reduction (3%) – incremental to 2% 2011 20% 

* For diesel technologies, learning is only applied to the cost of the emission control 

equipment, not the cost for the entire diesel system. 

The technologies for which we do not begin applying learning until 2014 all have the same 

reference source, the 2004 NESCCAF study, for which the sub-contractor was The Martec 

Group. In the work done for the 2004 NESCCAF report, Martec relied upon actual price quotes 

from Tier 1 automotive suppliers to develop automotive manufacturer cost estimates. Based on 

information presented by Martec to the National Academy of Sciences (NAS) Committee during 

their January 24, 2008, public meeting in Dearborn, Michigan,54 we understand that the Martec 

cost estimates incorporated some element of manufacturer learning. Martec stated that the Tier 1 

suppliers were specifically requested to provide price quotes which would be valid for three 

years (2009-2011), and that for some components the Tier 1 supplier included cost reductions in 

years two and three which the supplier anticipated could occur, and which they anticipated 

would be necessary in order for their quote to be competitive with other suppliers. Therefore, for 

this analysis, we did not apply any learning curve to any of the Martec-sourced costs for the first 

three years of this proposal (2011-2013). However, the theory of manufacturer learning is that it 

is a continuous process, though the rate of improvement decreases as the number of units 

 

54 “Variable Costs of Fuel Economy Technologies” Martec Group, Inc Report Presented to: Committee to Assess 

Technologies for Improving Light-Duty Vehicle Fuel Economy. Division on Engineering and Physical Systems, 

Board on Energy and Environmental Systems, the National Academy of Sciences, January 24, 2008. 
V-46 

produced increases. While we were not able to gain access to the detailed submissions from Tier 

1 suppliers which Martec relied upon for their estimates, we do believe that additional cost 

reductions will occur in the future for a number of the technologies for which we relied upon the 

Martec cost estimates for the reasons stated above in reference to the general learning curve 

effect. For those technologies we applied a learning curve beginning in 2014. Martec has 

recently submitted a study to the NAS Committee comparing the 2004 NESCCAF study with 

new updated cost information. Given that this study had just been completed, the agency could 

not take it into consideration for the NPRM. However, the agency will review the new study and 

consider its findings in time for the final rule. 

Manufacturers’ actual costs for applying these technologies to specific vehicle models are likely 

to include significant additional outlays for accompanying design or engineering changes to each 

model, development and testing of prototype versions, recalibrating engine operating parameters, 

and integrating the technology with other attributes of the vehicle. Manufacturers may also incur 

additional corporate overhead, marketing, or distribution and selling expenses as a consequence 

of their efforts to improve the fuel economy of individual vehicle models and their overall 

product lines. 

In order to account for these additional costs, NHTSA has applied an indirect cost multiplier of 

1.5 to its estimate of the vehicle manufacturers’ direct costs for producing or acquiring each fuel 

economy-improving technology to arrive at a consumer cost. This estimate was developed by 

Argonne National Laboratory in a recent review of vehicle manufacturers’ indirect costs. The 

Argonne study was specifically intended to improve the accuracy of future cost estimates for 

production of vehicles that achieve high fuel economy by employing many of the same advanced 

technologies considered in the agency’s analysis.55 Thus, its recommendation that a multiplier of 

1.5 be applied to direct manufacturing costs to reflect manufacturers’ increased indirect costs for 

deploying advanced fuel economy technologies appears to be appropriate for use in the current 

analysis. Historically, NHTSA has used almost the exact same multiplier, a multiplier of 1.51, as 

the markup from variable costs or direct manufacturing costs to consumer costs. This markup 

takes into account fixed costs, burden, manufacturer’s profit, and dealers profit. Table VII-2 of 

the PRIA shows the estimated incremental consumer costs for each vehicle type.56

E. Ensuring sufficient lead time 

In analyzing potential technological improvements to the product offerings for each 

manufacturer with a substantial share of the market, NHTSA added technologies based on our 

engineering judgment and expertise about possible adjustments to the detailed product plans 

submitted to NHTSA. Our decision whether and when to add a technology reflected our 

consideration of the practicability of applying a specific technology and the necessity for leadtime in its application. NHTSA recognizes that vehicle manufacturers must have sufficient lead 

time to incorporate changes and new features into their vehicles and hence added technologies in 

a cost-minimizing fashion. That is, we generally added technologies that were most costeffective and took into account the year of availability of the technologies. 

 

55 Vyas, Anant, Dan Santini, and Roy Cuenca, Comparison of Indirect Cost Multipliers for Vehicle Manufacturing, 

Center for Transportation Research, Argonne National Laboratory, April 2000. 

56 PRIA, VII-9. 
V-47 

NHTSA realizes that not all technologies will be available immediately or could be applied 

immediately and that there are different phase-in rates (how rapidly a technology is able to be 

applied across a manufacturer’s fleet of vehicles) applicable to each technology as well as 

windows of opportunities when certain technologies could be applied (i.e., when a product is 

redesigned or refreshed). 

1. Linking to redesign and refresh 

In the automobile industry there are two terms that describe when changes to vehicles occur: 

redesign and refresh. In projecting the technologies that could be applied to specific vehicle 

models, NHTSA tied the application of the majority of the technologies to a vehicle’s 

refresh/redesign cycle. Vehicle redesign usually encompasses changes to a vehicle’s 

appearance, shape, dimensions, and powertrain and is traditionally associated with the 

introduction of “new” vehicles into the market, and often is characterized as the next generation 

of a vehicle. In contrast vehicle refresh usually only encompasses changes to a vehicle’s 

appearance, and may include an upgraded powertrain and is traditionally associated with midcycle cosmetic changes to a vehicle within its current generation to make it appear “fresh.” 

Vehicle refresh traditionally occurs no earlier than two years after a vehicle redesign or at least 

two years before a scheduled redesign. Table 8 below contains a complete list of the 

technologies that were applied and whether NHTSA allowed them to be applied during a 

redesign year, a refresh year or during any model year is shown in the below table. 

Table 8. Technology Refresh and Redesign Application 

Technology Abbr. 

Can be applied 

during redesign 

model year only 

Can be applied 

during a redesign 

or refresh model 

year 

Can be applied 

during any model 

year 

Low Friction Lubricants LUB X X 

Engine Friction Reduction EFR X 

Variable Valve Timing (ICP) VVTI X 

Variable Valve Timing (CCP) VVTC X 

Variable Valve Timing (DCP) VVTD X 

Cylinder Deactivation DISP X 

Variable Valve Lift & Timing (CVVL) VVLTC X 

Variable Valve Lift & Timing (DVVL) VVLTD X 

Cylinder Deactivation on OHV DISPO X 

Variable Valve Timing (CCP) on OHV VVTO X 

Multivalve Overhead Cam with CVVL DOHC X 

Variable Valve Lift & Timing (DVVL) on OHV VVLTO X 

Camless Valve Actuation CVA X 

Stoichiometric GDI SIDI X 

Lean Burn GDI LBDI X 

Turbocharging and Downsizing TURB X 

HCCI HCCI X 

Diesel with LNT DSLL X 
V-48 

Diesel with SCR DSLS X 

5 Speed Automatic Transmission 5SP X 

Aggressive Shift Logic ASL X X 

Early Torque Converter Lockup TORQ X 

6 Speed Automatic Transmission 6SP X 

Automatic Manual Transmission AMT X 

Continuously Variable Transmission CVT X 

6 Speed Manual 6MAN X 

Improved Accessories IACC X 

Electronic Power Steering EPS X 

42-Volt Electrical System 42V X 

Low Rolling Resistance Tires ROLL X 

Low Drag Brakes LDB X 

Secondary Axle Disconnect – Unibody SAXU X 

Secondary Axle Disconnect - Ladder Frame SAXL X 

Aero Drag Reduction AERO X 

Material Substitution (1%) MS1 X 

Material Substitution (2%) MS2 X 

Material Substitution (5%) MS5 X 

ISG with Idle-Off ISGO X 

IMA/ISAD/BSG Hybrid (includes engine 

downsizing) IHYB X 

2-Mode Hybrid 2HYB X 

Power Split Hybrid PHYB X 

As can be seen in the above table, most technologies would only be applied by the Volpe model 

when a specific vehicle was due for a redesign or refresh. However, for a limited set of 

technologies, the model was not restricted to applying them during a refresh/redesign year and 

thus they were made available for application at any time. These specific technologies are: 

• Low Friction Lubricants 

• Improved Accessories 

• Low Rolling Resistance Tires 

• Low Drag Brakes 

All of these technologies are very cost-effective, can apply to multiple vehicle models/platforms 

and can be applied across multiple vehicle models/platforms in one year. Although they can also 

be applied during a refresh/redesign year, they are not restricted to that timeframe because their 

application is not viewed as necessitating a major engineering redesign and testing/calibration. 

There is an additional technology whose application is not tied to refresh/redesign, which is 

Aggressive Shift Logic (ASL). ASL is accomplished through reprogramming the shift points for 

a transmission to be more like a manual transmission. Upgrading a transmission to utilize ASL 

can happen at refresh/redesign, but because it is not a hardware change, it can also occur at other 

points in a vehicle’s design cycle. If a model that is scheduled for refresh/redesign has a 

transmission that is being upgraded to ASL, it is possible that all other vehicles that utilize the 

same transmission (which is usually produced at the same manufacturing plant) could be 
V-49 

upgraded at the same time to incorporate ASL and that ASL could permeate other vehicle 

models in years other than a refresh/redesign year. 

NHTSA based the redesign rates used in the Volpe Model on a combination of the 

manufacturers confidential product plans and on NHTSA’s engineering judgment. In most 

instances, NHTSA has accepted the projected redesign periods from the companies who 

provided them through MY 2013. If companies did not provide product plan date, NHTSA used 

publicly available data about vehicle redesigns to establish the redesign rates for the vehicles 

produced by these companies. 

NHTSA assumes that passenger cars will be redesigned every 5 years, based on the trend over 

the last 10-15 years for passenger cars to be redesigned every 5 years. These trends are reflected 

in the manufacturer production plans that NHTSA received in response to its request for product 

plan information and was confirmed by many automakers in meetings held with NHTSA to 

discuss various issues with manufacturers. 

NHTSA believes that the vehicle design process has progressed and improved rapidly over the 

last decade and these improvements have resulted in the ability of manufacturers to shorten the 

design process and to introduce vehicles more frequently to respond to competitive market 

forces. Almost all passenger cars will be on a 5-year redesign cycle by the end of the decade, 

with the exception being some high performance vehicles and vehicles’ with specific market 

niches. 

Currently, light trucks are redesigned every 5 to 7 years, with some vehicles having longer 

redesign periods (e.g., full-size vans). In the most competitive SUV and crossover vehicle 

segments, the redesign cycle currently averages slightly above 5 years. It is expected that the 

light truck redesign schedule will be shortened in the future due to competitive market forces and 

in response to fuel economy and other regulatory requirements. It is expected that by MY 2014, 

almost all light trucks will be redesigned on a 5-year cycle. Thus, for almost all vehicles 

scheduled for a redesign in model year 2014 and later, NHTSA estimated that all vehicles would 

be redesigned on a 5-year cycle. Exceptions were made for high performance vehicles and other 

vehicles that traditionally had longer than average design cycles (e.g., 2-seater sports cars). For 

those vehicles, NHTSA attempted to preserve the historic redesign cycle rates. 

2. Technology phase-in caps 

 In analyzing potential technological improvements to the product offerings for each 

manufacturer with a substantial share of the market, NHTSA added technologies based on our 

engineering judgment and expertise about possible adjustments to the detailed product plans 

submitted to NHTSA. Our decision whether and when to add a technology reflected our 

consideration of the practicability of applying a specific technology and the necessity for leadtime in its application. 

NHTSA recognizes that vehicle manufacturers must have sufficient lead time to incorporate 

changes and new features into their vehicles and that these changes cannot occur all at once, but 

must be phased in over time. As discussed above, our analysis addresses these realities in part 
V-50 

by timing the estimated application of most technologies to coincide with anticipated vehicle 

redesigns and/or freshenings. We have estimated that future vehicle redesigns can be 

implemented on a 5-year cycle with mid-cycle freshening, except where manufacturers have 

indicated plans for shorter redesign cycles. 

However, the agency further recognizes that engineering, planning and financial constraints 

prohibit most technologies from being applied across an entire fleet of vehicles within a year. 

Thus, as for the analysis supporting its 2006 rulemaking regarding light truck CAFE, the agency 

is employing overall constraints on the rates at which each technology can penetrate a 

manufacturer’s fleet. The Volpe model applies these “phase-in caps” by ceasing to add a given 

technology to a manufacturer’s fleet in a specific model year once it has increased the 

corresponding penetration rate by at least amount of the cap. Having done so, the model 

proceeds to apply other technologies in lieu of the “capped” technology. 

For its regulatory analysis in 2006, NHTSA applied phase-in caps expected to be consistent with 

NAS’ indication in its 2002 report that even existing technologies would require 4 to 8 years to 

achieve widespread penetration of the fleet. The NAS report, which is believed to be the only 

peer-reviewed source which provides phase-in rates, was relied upon for establishing the phasein caps that we used for all technologies, except diesels and hybrids, for which the report didn’t 

include that information. Most of the phase-in caps applied by the agency in 2006 ranged from 

25 percent (4 year introduction) to 17 percent (approximately 6 years, the midpoint of the NAS 

estimate). The agency assumed shorter implementation rates for technologies that did not 

require changes to the manufacturing line. For other technologies (e.g., hybrid and diesel 

powertrains), the agency employed phase-in caps as low as 3 percent, to reflect the major 

redesign efforts and capital investments required to implement these technologies. 

Considerable changes have occurred since NHTSA’s 2006 analysis, and even more since the 

2002 NAS report. Not only have fuel prices increased, but official forecasts of future fuel prices 

have increased, as well. This suggests a market environment in which consumers are more likely 

to demand fuel-saving technologies than previously anticipated, and it suggests a financial 

environment in which investors are more likely to invest in companies developing and producing 

such technologies. Indeed, some technologies have penetrated the marketplace more quickly 

than projected in 2006. Confidential product plan information submitted to NHTSA in 2007 and 

information from suppliers confirm that the rate of technology penetration has increased as 

compared to 2006. 

Also, the statutory environment has changed since 2006. With the enactment of EISA, Congress 

has adopted the specific objectives of increasing new vehicle fuel economy to at least 35 mpg by 

2020 and making ratable progress toward that objective in earlier model years. This reduces 

manufacturers’ uncertainty about the general direction of future fuel economy standards in the 

United States. Moreover, developments in other regions (e.g., Europe) and countries (e.g., 

Canada and China) suggest that the generalized expectation that future vehicles will perform 

well with respect to energy efficiency is not unique to the United States. Discussions with 

manufacturers in late 2007 and early 2008 indicate that the industry is highly sensitive to all of 

these developments and has been anticipating the need to accelerate the rate of technology 

deployment in response to the passage of major energy legislation in the U.S. 
V-51 

Considering these developments, the agency revisited the phase-in caps it had applied in 2006 

and determined that it would be appropriate to relax many of them. In our judgment, most of the 

engine technologies could penetrate the fleet in as quickly as five years—rather than in the six 

we previously estimated—as long as they are applied during redesign. Low friction lubricants 

are already widely used, and our expectation is that they can quickly penetrate the remainder of 

the fleet. Therefore, we relaxed the 25 percent (4-year) phase-in cap to 50 percent (2 years). 

Similarly, product plans indicate that transmissions with 5 or more forward gears will widely 

penetrate the fleet even without the current proposal. Also, given the technology cost and 

effectiveness estimates discussed above, the Volpe model frequently estimates that 

manufacturers will “leapfrog” past 5-speed transmissions to apply more advanced transmissions 

(e.g., 6-speed or AMT). We have therefore increased the phase-in cap for 5-speed transmissions 

from 25 percent (4 years) to 100 percent (1 year). However, in our judgment, phase-in caps of 

17 percent (6 years) are currently still appropriate for most other transmission technologies. 

Although NHTSA has applied phase-in caps of 25 percent (4 years) for most remaining 

technologies, we continue to anticipate that phase-in caps of 3 percent are appropriate for some 

advanced technologies, such as hybrids and diesels. Although engine, vehicle, and exhaust 

aftertreatment manufacturers have, more recently, expressed greater optimism than before 

regarding the outlook for light vehicle diesel engines, our expectation is that the phase-in cap that 

we have chosen is appropriate at this time. We also estimate that a 3 percent rate is appropriate 

for hybrid technologies, which are very complex, require significant engineering resources to 

implement, but are just now starting to penetrate the market. 

Table 9 below presents the phase-in caps applied in the current analysis, with rates from the 

analysis of the 2006 final rule provided for comparison. NHTSA requests comments on the 

phase-in caps shown here, and on whether slower or faster rates would be more appropriate and, 

if so, why. 

Table 9. Phase-in Cap Application 

Technology 

2006 

Final 

Rule 

Current 

NPRM 

Low Friction Lubricants 25% 50% 

Engine Friction Reduction 17% 20% 

Variable Valve Timing (ICP) 17% 20%

Variable Valve Timing (CCP) 17% 20%

Variable Valve Timing (DCP) 17% 20%

Cylinder Deactivation 17% 20%

Variable Valve Lift & Timing (CVVL) 17% 20%

Variable Valve Lift & Timing (DVVL) 17% 20%

Cylinder Deactivation on OHV 17% 20%

Variable Valve Timing (CCP) on OHV 17% 20%

Multivalve Overhead Cam with CVVL 17% 20%

Variable Valve Lift & Timing (DVVL) on OHV 17% 20%

Camless Valve Actuation 10% 20%

Stoichiometric GDI 3% 20% 

Diesel following GDI-S (SIDI) 3% 3% 

Lean Burn GDI 20% 
V-52 

Turbocharging and Downsizing 17% 20% 

Diesel following Turbo D/S 3% 3% 

HCCI 13% 

Diesel following HCCI 3% 3% 

5 Speed Automatic Transmission 17% 100% 

Aggressive Shift Logic 17% 25% 

Early Torque Converter Lockup 25% 

6 Speed Automatic Transmission 17% 17% 

Automated Manual Transmission 17% 17% 

Continuously Variable Transmission 17% 17% 

6 Speed Manual 17% 

Improved Accessories 25% 25% 

Electric Power Steering 17% 25% 

42-Volt Electrical System 17% 25% 

Low Rolling Resistance Tires 25% 25% 

Low Drag Brakes 17% 25% 

Secondary Axle Disconnect – Unibody 17% 17% 

Secondary Axle Disconnect - Ladder Frame 17% 17% 

Aero Drag Reduction 17% 17% 

Material Substitution (1%) 17% 17% 

Material Substitution (2%) 17% 17% 

Material Substitution (5%) 17% 17% 

ISG with Idle-Off 5% 3% 

IMA/ISAD/BSG Hybrid (includes engine downsizing) 5% 3% 

2-Mode Hybrid 5% 3% 

Power Split Hybrid 5% 3% 

Plug-in Hybrid 3% 

B. The Volpe model 

1. What is the Volpe model?

As it did for the development and analysis of the April 2006 light truck final rule, in developing 

this proposal NHTSA made significant use of a peer-reviewed modeling system developed by 

the Department of Transportation’s Volpe National Transportation Systems Center (Volpe 

Center). The CAFE Compliance and Effects Modeling System (referred to herein as the Volpe 

model) serves two fundamental purposes: identifying technologies each manufacturer could 

apply in order to comply with a specified set of CAFE standards, and calculating the costs and 

effects of manufacturers’ application of technologies. 

Before working with the Volpe Center to develop and apply this model, NHTSA had considered 

other options, including other modeling systems. NHTSA was unable to identify any other 

system that could operate at a sufficient level of detail with respect to manufacturers’ future 

products, which involve thousands of unique vehicle models using hundreds of unique engines 

and hundreds of unique transmissions. NHTSA was also unable to identify any other system that 
V-53 

could simulate a range of different possible reforms to CAFE standards. The Volpe model 

provides these and other capabilities, and helps NHTSA examine potential regulatory options. 

2. How does the Volpe model apply technologies to manufacturers’ future fleets?

The Volpe model begins with an “initial state” of the domestic vehicle market, which in this case 

is the market for passenger cars and light trucks to be sold during the period covered by the 

proposed rule. The vehicle market is defined on a model-by-model, engine-by-engine, and 

transmission-by-transmission basis, such that each defined vehicle model refers to a separatelydefined engine and a separately-defined transmission. 

For the model years covered by the current proposal, the light vehicle (passenger car and light 

truck) market forecast included more than 3,000 vehicle models, more than 400 specific engines, 

and nearly 400 specific transmissions.57 This level of detail in the representation of the vehicle 

market is vital to an accurate analysis of manufacturer-specific costs and the analysis of reformed 

CAFE standards, and is much greater than the level of detail used by many other models and 

analyses relevant to light vehicle fuel economy. Because CAFE standards apply to the average 

performance of each manufacturer’s fleets of cars and light trucks, the impact of potential 

standards on individual manufacturers cannot be credibly estimated without analysis of 

manufacturers’ planned fleets. NHTSA has used this level of detail in CAFE analysis 

throughout the history of the program. Furthermore, because required CAFE levels under an 

attribute-based CAFE standard depend on manufacturers’ fleet composition, the stringency of an 

attribute-based standard cannot be predicted without performing analysis at this level of detail. 

Examples of other models and analyses that NHTSA and Volpe Center staff have considered 

include DOE’s NEMS, Oak Ridge National Laboratory’s (ORNL) Transitional Alternative Fuels 

and Vehicles (TAFV) model, and the California Air Resources Board’s (CARB) analysis 

supporting California’s adopted greenhouse gas emissions standards for light vehicles. 

DOE’s NEMS represents the light-duty fleet in terms of four “manufacturers” (domestic cars, 

imported cars, domestic light trucks, and imported light trucks), twelve vehicle market classes 

(e.g., “standard pickup”), and sixteen power train/fuel combinations (e.g., methanol fuel-cell 

vehicle).58 Therefore, as currently structured, NEMS is unable to estimate manufacturer-specific 

implications of attribute-based CAFE standards. 

 

57 The market forecast is an input to the Volpe model developed by NHTSA using product plan information 

provided to the agency by individual vehicle manufacturers in response to NHTSA’s requests. The submitted 

product plans contain confidential business information (CBI), which the agency is prohibited by federal law from 

disclosing. As the agency receives new product plan information in response to future requests, the market forecast 

is updated. 

58 U.S. Department of Energy, “Transportation Sector Module of the National Energy Modeling System: Model 

Documentation 2007,” DOE/EIA-M070, May 2007. Available at

http://tonto.eia.doe.gov/FTPROOT/modeldoc/m070(2007).pdf (last accessed Mar. 12, 2008). NEMS’s 

Manufacturers Technology Choice Submodule (MTCS) is believed to have logical structures similar to those in 

Energy and Environmental Analysis, Inc.’s (EEA’s) Fuel Economy Regulatory Analysis Model (FERAM). 

However, FERAM documentation and source code have not been made available to NHTSA or Volpe Center staff. 
V-54 

TAFV accounts for many power train/fuel combinations, having been originally designed to aid 

understanding of possible transitions to alternative fueled vehicles, but it represents the lightduty fleet as four aggregated (i.e., industry-wide) categories of vehicles: small cars, large cars, 

small light trucks, and large light trucks.59 Thus, again, as currently structure, TAFV is unable to 

estimate manufacturer-specific implications of attribute-based CAFE standards. 

CARB’s analysis of light vehicle GHG emissions standards uses two levels of accounting. First, 

based on a report prepared for Northeast States Center for a Clean Air Future (NESCCAF), 

CARB represents the light-duty fleet in terms of five “representative” vehicles. Use of these 

“representative” vehicles ignores the fact that the engineering characteristics of individual 

vehicle models vary widely both among manufacturers and within manufacturers’ individual 

fleets. For each of these five vehicles, NESCCAF’s report contains the results of full vehicle 

simulation given several pre-specified technology “packages.”60 Second, to evaluate 

manufacturer-specific regulatory costs, CARB essentially reduces each manufacturer’s fleet to 

only two average test weights, one for each of California’s two regulatory classes.61 Even for a 

flat standard such as considered by California, NHTSA would not base its analysis of 

manufacturer-level costs on this level of aggregation. Use of CARB’s methods would not enable 

NHTSA to estimate manufacturer-specific implications of the attribute-based CAFE standards 

proposed today.62

The Volpe model also uses several additional categories of data and estimates provided in 

various external input files: 

One input file specifies the characteristics of fuel-saving technologies to be represented, and 

includes, for each technology, the first year in which the technology is expected to be ready for 

commercial application; upper and lower estimates of the effectiveness and cost (retail price 

equivalent) of the technology; coefficients defining the extent to which costs are expected to 

decline as a result of “learning effects” (discussed below); inclusion or exclusion of the 

technology on up to three technology “paths”; and constraints (“phase-in caps”) on the annual 

rate at which manufacturers are estimated to be able to increase the technology’s penetration 

rate. These technology characteristics and estimates are specified separately for each of the 

following categories of vehicles: small sport/utility vehicles (SUVs), midsize SUVs, large 

SUVs, small pickups, large pickups, minivans, subcompact cars, compact cars, midsize cars, and 

 

59 Greene, David. “TAFV Alternative Fuels and Vehicles Choice Model Documentation,” ORNL//TM—2001//134, 

July 2001. Available at http://www-cta.ornl.gov/cta/Publications/Reports/ORNL_TM_2001_134.pdf (last accessed 

Mar. 12, 2008). 

60 Northeast States Center for a Clean Air Future (NESCCAF), Reducing Greenhouse Gases from Light-Duty 

Vehicles (2004). Available at http://bronze.nescaum.org/committees/mobile/rpt040923ghglightduty.pdf (last 

accessed Mar. 12, 2008). 

61 California Environmental Protection Agency, Air Resources Board, Staff Report: Initial Statement of Reasons 

(CARB ISOR) (2004), at 111-114. Available at http://www.arb.ca.gov/regact/grnhsgas/grnhsgas.htm (scroll down 

to “Public Hearing Notice and Related Material”) (last accessed Sept. 11, 2007). We note that California has 

adopted these standards but is currently unable to enforce them, due to EPA’s February 29, 2008 denial of 

California’s request for waiver of federal preemption under Section 209 of the Clean Air Act. For information on 

EPA’s decision, see http://www.epa.gov/otaq/ca-waiver.htm. California filed a petition in the 9th Circuit Court of 

Appeals challenging EPA’s denial of the waiver on January 2, 2008. 

62 Although CARB’s analysis covered a wider range of model years than does NHTSA’s analysis, this does not 

lessen the importance of a detailed representation of manufacturers’ fleets. 
V-55 

large cars. In addition, the input file defining technology characteristics can (but need not) 

contain specified “synergies” between technologies—that is, differences in a given technology’s 

effect on fuel consumption that result from the presence of other technologies. 

Another input file specifies vehicular emission rates for the following pollutants: carbon 

monoxide (CO), volatile organic compounds (VOCs), nitrogen oxides (NOx), particulate matter 

(PM), and sulfur dioxide (SO2). These rates are defined on a model year-by-model year and 

calendar year-by-calendar year basis, and are used to estimate changes in emissions that result 

from changes in vehicular travel (i.e., vehicle-miles traveled or VMT). 

A third input file specifies a variety of economic and other data and estimates. The model can 

accommodate vehicle survival (i.e., percent of vehicles of a given vintage that remain in service) 

and mileage accumulation (i.e., annual travel by vehicles of a given vintage) rates extending as 

many years beyond the year of sale as for which estimates are available and use those for 

estimating VMT, fuel consumption, and emissions. The model can also accommodate forecasts 

of price and fuel taxation rates for up to seven fuels (e.g., gasoline, diesel) over a similar period. 

The model uses pump prices (i.e., including taxes) to estimate the value manufacturers expect 

vehicle purchasers to place on saved fuel, because they indicate the amount by which the 

manufacturer is expected to consider itself able to increase the retail price of the vehicle based on 

the purchaser’s consideration of the vehicle’s increased fuel economy. However, the model uses 

pretax fuel prices to estimate the monetized societal benefits of reduced fuel consumption, 

because fuel taxes represent transfers of resources from fuel buyers to government agencies 

rather than real resources that are consumed in the process of supplying or using fuel, so their 

value must be deducted from retail fuel prices to determine the value of fuel savings to the U.S. 

economy. 

Other economic inputs include the rebound effect coefficient (i.e., the elasticity of VMT with 

respect to the per-mile cost of fuel); the discount rate; the “payback period” (i.e., the number of 

years manufacturers are estimated to assume vehicle purchasers consider when taking into 

account fuel savings); the “gap” between laboratory and actual fuel economy; the per-vehicle 

value of travel time (in dollars per hour); the economic costs (in dollars per gallon) of petroleum 

consumption; various external costs (all in dollars per mile) associated with changes in vehicle 

use; damage costs (all on a dollar per ton basis) for each of the above-mentioned criteria 

pollutants; and the rate at which noncompliance causes civil penalties. Section V.A.4 below 

describes in much more detail how these inputs are included and used by the model.

The model also accommodates input data and estimates addressing the properties of different 

fuels. These include upstream carbon dioxide and criteria pollutant emission rates (i.e., U.S. 

emissions resulting from the production and distribution of each fuel), density (pounds/gallon), 

energy density (BTU/gallon), carbon content, shares of fuel savings leading to reduced domestic 

refining, and relative shares of different gasoline blends. These fuel properties and related 

estimates are used to calculate changes in domestic upstream emissions resulting from changes 

in fuel consumption. 

Coefficients defining the probability distributions to apply when performing sensitivity analysis 

(i.e., Monte Carlo simulation) are also specified in this input file. These coefficients determine 
V-56 

the likelihood that any given value will be selected when performing this type of analysis (e.g., 

the likelihood that a rebound effect of -0.1 will be tested). High and low fuel price forecasts are 

also specified in this input file for this purpose. 

The final input file contains CAFE scenarios to be examined. The model accommodates a 

baseline (i.e., business-as-usual) scenario and different alternative scenarios. Effects of the 

alternative scenarios are calculated relative to results for the baseline scenario. Each scenario 

defines the coverage, structure, and stringency of CAFE standards for each of the covered model 

years. 

With all of the above input data and estimates, the modeling system develops an estimate of a set 

of technologies each manufacturer could apply in response to each specified CAFE scenario. 

Because manufacturers have many choices regarding how to respond to CAFE standards, it is 

impossible to predict precisely how a given manufacturer would respond to a given set of 

standards. The modeling system begins with the “initial state” (i.e., business-as-usual) of each 

manufacturer’s future vehicles, and accumulates the estimated costs of progressive additions of 

fuel-saving technologies. Within a set of specified constraints, the system adds technologies 

following a cost-minimizing approach, because this is what NHTSA expects a manufacturer 

would do in real life. At each step, the system evaluates the effective cost of applying available 

technologies to individual vehicle models, engines, or transmissions, and selects the application 

of technology that produces the lowest effective cost. The effective cost estimated to be 

considered by the manufacturer is calculated by adding the total incurred technology costs (in 

retail price equivalent or RPE), subtracting the reduction in civil penalties owed for 

noncompliance with the CAFE standard, subtracting the estimated value63 of the reduction in 

fuel costs, and dividing the result by the number of affected vehicles. 

In representing manufacturer decision-making in response to a given CAFE standard, the 

modeling system accounts for the fact that historically some manufacturers have been unwilling 

to pay penalties and some have been willing to do so. Thus, the system applies technologies 

until any of the following conditions are met: the manufacturer no longer owes civil penalties 

for failing to meet the applicable standard, the manufacturer has exhausted technologies expected 

to be available in that model year, or the manufacturer is estimated to be willing to pay civil 

penalties, and doing so is estimated to be less expensive than continuing to add technologies. 

The system then progresses to the next model year (if included in the vehicle market and 

scenario input files), “carrying over” technologies where vehicle models are projected to be 

succeeded by other vehicle models.64

In the modeling system, this “compliance simulation” is constrained in several ways. First, 

technologies are defined as being applicable or not applicable to each of the ten vehicle 

categories listed above. The vehicle market forecast input file may also define some 

 

63 The estimated value of the reduction in fuel costs represents the amount by which the manufacturer is expected to 

consider itself able to increase the retail price of the vehicle based on the purchaser’s consideration of the vehicle’s 

increased fuel economy. This calculation considers the change in the discounted outlays for fuel (and fuel taxes) 

during a “payback period” specified as an input to the model. 64 For example, if Honda is expected to produce the Civic in 2012 and 2013, a version of the Civic estimated to be 

produced in 2013 may carry over technologies from a version of the Civic produced in 2012 if the latter is identified 

as a “predecessor” of the former. 
V-57 

technologies as being already present or not applicable to specific vehicles, engines or 

transmissions. For example, a manufacturer may have indicated it plans to use low-drag brakes 

on some specific vehicle model, or NHTSA may expect that another manufacturer is not likely to 

apply a 7- or 8-speed transmission after it installs a 6-speed transmission on a vehicle. Second, 

some technologies are subject to specific “engineering constraints.” For example, secondaryaxle disconnect can only be applied to vehicles with four-wheel (or all-wheel) drive. Third, 

some technologies (e.g., conversion from pushrod valve actuation to overhead cam actuation) are 

nearly always applied only when the vehicle is expected to be redesigned and others (e.g., 

cylinder deactivation) are applied only when the vehicle is expected to be refreshed or 

redesigned, so the model will only apply them at those particular points. Fourth, once the system 

applies a given technology to a percentage of a given manufacturers’ fleet exceeding a specified 

phase-in cap, the system instead applies other technologies. The third and fourth of these 

constraints are intended to produce results consistent with manufacturers’ product planning 

practices and with limitations on how quickly technologies can penetrate the fleet. 

One important aspect of this compliance simulation is that it does not attempt to account for 

either CAFE credits or intentional over-compliance. In the real world, manufacturers may earn 

CAFE credits by selling flex-fueled vehicles (FFVs) and/or by exceeding CAFE standards, and 

may, within limitations, count those credits toward compliance in future or prior model years. 

However, EPCA and EISA do not allow NHTSA to consider these flexibilities in setting the 

standards. Therefore, the Volpe model does not attempt to account for these flexibilities. 

Another possibility NHTSA and Volpe Center staff have considered, but do not yet know how to 

analyze, is the potential that manufacturers might “pull ahead” the implementation of some 

technologies in response to CAFE standards known to be increasing over time. For example, if a 

manufacturer plans to redesign many vehicles in MY2011 and not in MY2013, but the standard 

in MY2013 is considerably higher in MY2013 than in MY2011, the manufacturer might find it 

less expensive during MY2011-MY2013 (taken together) to apply more technology in MY2011 

than is necessary for compliance with the MY2011 standard. Under some circumstances, doing 

so might make sense even setting aside the potential to earn and bank CAFE credits. 

NHTSA and Volpe Center staff have discussed the potential to represent this type of response, 

but have thus far encountered two challenges. First, NHTSA is not certain that in determining 

the maximum feasible standard in a given model year, it would be appropriate to count on 

manufacturers overcomplying with standards in preceding model years. Second, considering 

other inter-model year dependencies (e.g., technologies that carry over between model years, 

phase-in caps that accumulate across model years, volume-based learning curves), Volpe Center 

staff currently anticipate that some iterative procedure would likely be required. Also, the 

agency wonders whether trying to represent this type of response would require make undue 

implicit assumptions regarding manufacturers’ ability to predict future market conditions. 

Although NHTSA and Volpe Center staff will continue to explore the potential to represent 

inter-model year timing, it is not yet clear that it will be appropriate and feasible to do so in the 

near term. 

The agency requests comment on the appropriateness under EPCA of considering (in the 

standard-setting context) this type of anticipatory application of technology. The agency further 
V-58 

requests comment on appropriate methodologies for representing such decisions by 

manufacturers. 

3. What effects does the Volpe model estimate?

 

Having completed this compliance simulation for all manufacturers and all model years, the 

system calculates the total cost of all applied technologies, as well as a variety of effects of 

changes in fuel economy. The system calculates year-by-year mileage accumulation, taking into 

account any increased driving estimated to result from the rebound effect. Based on the 

calculated mileage accumulation and on fuel economy and the estimated gap between laboratory 

and actual fuel economy, the system calculates year-by-year fuel consumption. Based on 

calculated mileage accumulation and fuel consumption, and on specified emission factors, the 

system calculates future full fuel-cycle domestic carbon dioxide and criteria pollutant emissions. 

The system calculates total discounted and undiscounted national societal costs of year-by-year 

fuel consumption, taking into account estimated future fuel prices (before taxes) and the 

estimated economic externalities of fuel consumption. Based on changes in year-by-year 

mileage accumulation, the system calculates changes in consumer surplus related to additional 

travel, as well as economic externalities related to additional congestion, accidents, and noise 

stemming from additional travel. The system calculates the value of time saved because 

increases in fuel economy produce increases in driving range, thereby reducing the frequency 

with which some vehicles require refueling. The system calculates the monetary value of 

damages resulting from criteria pollutants. Finally, the system accumulates all discounted and 

undiscounted societal benefits of each scenario as compared to the baseline scenario. For each 

model year, the system compares total incurred technology costs to the total present value of 

societal benefits for each model year, calculating net societal benefits (i.e., discounted societal 

benefits minus total incurred technology costs) and the benefit-cost ratio (i.e., discounted societal 

benefits divided by total incurred technology costs). 

One important effect not currently estimated by the Volpe model is the market response to 

CAFE-induced changes in vehicle prices and fuel economy levels. NHTSA and Volpe Center 

staff have considered developing and applying a market share model capable of estimating 

changes in sales of individual vehicle models. Doing so would allow estimation of the feedback 

between market shifts and CAFE requirements. For example, if the relative market share of 

vehicles with small footprints increases, the average required CAFE level under a footprintbased standard will also increase. 

In an early experimental version of the Volpe model, Volpe Center staff included a market share 

model using a nested multinomial logit specification to calculate model-by-model changes in 

sales volumes. This allowed the Volpe model to calculate the resulting changes in 

manufacturers’ required CAFE levels, and to seek iteratively a solution at which prices, fuel 

economy levels, sales volumes, and required CAFE levels converged to stable values. Although 

the market share model appeared to operate properly (and to converge rapidly), Volpe Center 

staff suspended its development because of three challenges: 

First, Volpe Center staff were not successful in calibrating a logically consistent set of 

coefficients for the underlying multinomial logit model. The analysis, performed using 
V-59 

information from a known (2002 model year) fleet, consistently yielded one or more coefficients 

that were either directionally incorrect (e.g., indicating that some attributes actually detract from 

value) or implausibly large (e.g., indicating that some attributes were of overwhelming value). 

Although Volpe Center staff tested many different specifications of the market share model, 

none produced results that appeared to merit further consideration. 

Second, NHTSA and Volpe Center staff are not confident that baseline sales prices for individual 

vehicle models, which would be required by a market share model, can be reliably predicted. 

Although NHTSA requests that manufacturers include planned MSRPs in product plans 

submitted to NHTSA, MSRPs do not include the effect of various sales incentives that can 

change actual selling prices. The availability and dollar value of suchincentives have been 

observed to vary considerably, but not necessarily predictably. 

Finally, before applying a market share model, it would be necessary to estimate how 

manufacturers would allocate compliance costs among vehicle models. Although one obvious 

approach would be to assume that all costs would be passed through in the form of higher prices 

for those vehicle models with improved fuel economy, other approaches are perhaps equally 

plausible. For example, a manufacturer might shift compliance costs toward high-demand 

vehicles in order to better compete in certain market segments. Although the above-mentioned 

experimental version of the Volpe model included a “cost allocation” model that offered several 

different allocation options, NHTSA and Volpe Center staff never achieved confidence that these 

aspects of manufacturer decisions could be reasonably estimated. 

NHTSA and Volpe Center staff are continuing to explore options for including these types of 

effects. At the same time, EPA has contracted with Resources for the Future (RFF) to develop a 

potential market share model. Depending on the extent to which these efforts are successful, the 

Volpe model could at some point be modified to include cost allocation and market share 

models. NHTSA seeks comment on possible methodologies for incorporating market responses 

to CAFE-induced changes in vehicle price and fuel economy in the Volpe model. In particular, 

NHTSA seeks comments addressing the concerns identified above regarding the formulation and 

calibration of a market share model, the estimation of future vehicle prices, and the estimation of 

manufacturers’ decisions regarding the allocation of compliance costs. 

4. How can the Volpe model be used to calibrate and evaluate potential CAFE 

standards?

 

The modeling system can also be applied in a more highly-automated mode whereby the optimal 

shape of an attribute-based CAFE standard may be estimated and its stringency may be set at a 

level that produces a specified total technology cost or average required CAFE level among a 

specified set of manufacturers, or that is estimated to maximize net societal benefits. The first 

step in this operating mode involves identifying manufacturer-by-manufacturer CAFE levels at 

which societal benefits are estimated to be maximized. The second step involves combining the 

resultant fleets and statistically fitting a constrained logistic curve of the following form: 
V-60 

( )

( )

1

1 11

1

FOOTPRINT MIDPOINT WIDTH

FOOTPRINT MIDPOINT WIDTH

UPPER LOWER UPPER

TARGET

e

LIMIT LIMIT LIMIT e

−

−

= ⎛ ⎞

+ − ⎜ ⎟ ⎝ ⎠ +

Here, TARGET is the fuel economy target (in mpg) applicable to vehicles of a given footprint 

(FOOTPRINT, in square feet), LIMITLOWER and LIMITUPPER are the function’s lower and upper 

asymptotes (also in mpg), e is approximately equal to 2.718,65 MIDPOINT is the footprint (in 

square feet) at which the inverse of the fuel economy target falls halfway between the inverses of 

the lower and upper asymptotes, and WIDTH is a parameter (in square feet) that determines how 

gradually the fuel economy target transitions from the upper toward the lower asymptote as the 

footprint increases. Figure V-2 below shows an example of a logistic target function, where 

LIMITLOWER = 20 mpg, LIMITUPPER = 30 mpg, MIDPOINT = 40 square feet, and WIDTH = 5 

square feet: 

Figure V-2. Sample Logistic Curve 

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60 70 80 90 100

Footprint (Square Feet)

Target (Miles per Gallon)

LIMITUPPER

LIMITLOWER

The lower asymptote is determined by calculating the average fuel economy of the largest 

vehicles in the “socially optimized” fleet discussed above, where the percentage of the fleet to 

consider is specified externally. Similarly, the upper asymptote is determined by calculating the 

average fuel economy of the smallest vehicles in the same fleet. Initial values of the other two 

 

65 The number e is one of the most important numbers in mathematics and statistics. The function has a hockey 

stick appearance when plotted. The value of e itself is a never ending number whose first 8 digits equal 2.7182818. 

NHTSA uses it here because it occurs in many natural processes and tends to fit data well. In the last light truck 

rulemaking, NHTSA examined several functional forms that did not rely on e, but they were judged not to provide 

as good a fit for the data. We are using the same conclusion here. 
V-61 

coefficients of the logistic function are determined through a standard statistical technique 

(nonlinear least-square regression), except as discussed in sections V and VI below regarding the 

adjusting of the original curve for the passenger car function. 

Following this initial calibration of the target function, the system adjusts the lower and upper 

asymptotes uniformly (on a gallon per mile basis) until one of the following externally specified 

conditions is met: the average CAFE level required of the included manufacturers 

approximately equals an externally specified goal; net societal benefits (i.e., total benefits minus 

total costs) are maximized, or total benefits are as close as observed (among evaluated stringency 

levels) to total costs. Due to rounding of fuel economy and CAFE levels, the first condition can 

only be satisfied on an approximate basis. 

The modeling system provides another type of higher-level automation—the ability to perform 

uncertainty analysis, also referred to as Monte Carlo simulation. For some input parameters, 

such as technology costs, values can be tested over a specified continuous probability 

distribution. For others, such as fuel prices, discrete scenarios (e.g., high, low, and reference 

cases), each with a specified probability, can be tested. The system performs sensitivity analysis 

by randomly selecting values for parameters to be varied, performing the compliance simulation 

and effects calculations, repeating these results many times and recording results for external 

analysis. This operating mode enables the examination of the uncertainty of high-level results 

(e.g., total costs, fuel savings, or net societal benefits), as well as their sensitivity to variations in 

the model’s input parameters. 

5. How has the Volpe model been updated since the April 2006 light truck CAFE final 

rule?

Several changes were made to the Volpe model between the analysis reported in the April 2006 

light truck final rule and the analysis of the current NPRM. As discussed above, the set of 

technologies represented was updated, the logical sequence for progressing through these 

technologies was changed, methods to account for “synergies” (i.e., interactions) between 

technologies and technology cost reductions associated with a manufacturer’s “learning” were 

added, the effective cost calculation used in the technology application algorithm was modified, 

and the procedure for calibrating a reformed standard was changed, as was the procedure for 

estimating the optimal stringency of a reformed standard. 

As discussed in Section III above, the set of technologies considered by the agency has evolved since 

the previous light truck CAFE rulemaking. The set of technologies now included in the Volpe model 

is shown below in Table V-7, with codes used by the model to refer to each technology. 

Table V-7. Revised Technology Set for Volpe Model 

Technology Code (for Model) 

Low Friction Lubricants LUB 

Engine Friction Reduction EFR 

Variable Valve Timing (Intake Cam Phasing) VVTI 
V-62 

Variable Valve Timing (Coupled Cam Phasing) VVTC 

Variable Valve Timing (Dual Cam Phasing) VVTD 

Cylinder Deactivation DISP 

Variable Valve Lift & Timing (Continuous VVL) VVLTC 

Variable Valve Lift & Timing (Discrete VVL) VVLTD 

Cylinder Deactivation on Overhead Valve (OHV) DISPO 

Variable Valve Timing (CCP) on OHV VVTO 

Multivalve Overhead Cam with CVVL DOHC 

Variable Valve Lift & Timing (DVVL) on OHV VVLTO 

Camless Valve Actuation CVA 

Stoichiometric Gasoline Direct Injection (GDI) SIDI 

Lean Burn GDI LBDI 

Turbocharging and Downsizing TURB 

Homogeneous Charge Compression Ignition HCCI 

Diesel with Lean NOx Trap (LNT) DSLL 

Diesel with Selective Catalytic Reduction (SCR) DSLS 

5 Speed Automatic Transmission 5SP 

Aggressive Shift Logic ASL 

Early Torque Converter Lockup TORQ 

6 Speed Automatic Transmission 6SP 

Automatic Manual Transmission AMT 

Continuously Variable Transmission CVT 

6 Speed Manual 6MAN 

Improved Accessories IACC 

Electronic Power Steering EPS 

42-Volt Electrical System 42V 

Low Rolling Resistance Tires ROLL 

Low Drag Brakes LDB 

Secondary Axle Disconnect – Unibody SAXU 

Secondary Axle Disconnect - Ladder Frame SAXL 

Aero Drag Reduction AERO 

Material Substitution (1%) MS1 

Material Substitution (2%) MS2 

Material Substitution (5%) MS5 

Integrated Starter/Generator (ISG) with Idle-Off ISGO 
V-63 

IMA/ISAD/BSG Hybrid (includes engine downsizin IHYB 

2-Mode Hybrid 2HYB 

Power Split Hybrid PHYB 

Full Diesel Hybrid DHYB 

The logical sequence for progressing between these technologies has also been changed. As in the 

previous version of the Volpe model, technologies are assigned to groups (e.g., engine technologies) 

and the model follows a cost-minimizing approach to selecting technologies. However, the model 

now includes some “branch points” at which it selects from two or more technologies within the same 

group. This enables a more detailed representation of some technologies that have multiple variants 

(e.g., variable valve timing) and, as relevant to the applicability of different technologies, more 

specific differentiation between technologies that have already been applied to vehicles (e.g., single 

versus dual overhead cam engines). This revised logical sequencing is expected to produce results that 

are more realistic in terms of the application of technologies to different vehicle models. For example, 

in this analysis OHV engines and OHC engines were considered separately, and the model was 

generally not allowed to apply multivalve OHC technology to OHV engines (except where continuous 

variable valve timing and lift is applied to OHV engines, in which case the model assumes conversion 

to DOHC valvetrain). 

Figure V-3 below shows the resultant “decision tree” for the group of engine technologies. As an 

example of the “branching” mentioned above, having applied cylinder deactivation and coupled cam 

phasing to an overhead valve engine, the Volpe model selects either discrete valve lift or an engine 

redesign to multivalve overhead cam with continuous variable valve Figure V-4 shows the decision 

tree for transmission technologies, and Figure V-5 shows the decision trees for other technologies. 

Figure V-3. Engine Technology Decision Tree 
V-64 

Low-Friction 

Lubricants

Engine Friction 

Reduction

VVT

(ICP)

Cylinder 

Deactivation

VVT

(Coupled

Cam Phasing)

VVLT

(Continuous VVL)

VVLT

(Discrete VVL)

VVT

(Dual

Cam Phasing)

Stoichiometric

GDI

HCCI

Diesel

Replacing

Turbo SI GDI

Diesel

Replacing

HCCI

OHC

DOHC DOHC

DOHC DOHC

VVT

(Coupled

Cam Phasing)

Cylinder 

Deactivation

OHV

DOHC

with

Continuous VVL

VVLT

(Discrete VVL)

Turbocharging

and

Downsizing

SOHC

SOHC

Diesel

Replacing

NA SI GDI
V-65 

Figure V-4. Transmission Technology Decision Tree 

Automatic

5-Speed

Aggressive

Shift Logic

AMT

6/7/8-Speed

CVT

Early Torque 

Converter Lockup

Unibody

ISG with Idle-Off

IMA/ISAD/BSG

Hybrid

2-Mode

Hybrid

Power Split

Hybrid

Automatic Transmission Only

Unibody

Manual

5-Speed

6/7/8-Speed

Ladder Frame
V-66 

Figure V-5. Decision Trees for Other Technologies 

Improved 

Accessories

42-Volt System

Electric Power 

Steering

Low Rolling 

Resistance Tires

Secondary Axle 

Disconnect

Low Drag Brakes

Materials 

Substitution (1%)

Materials 

Substitution (2%)

Materials 

Substitution (5%)

Aerodynamic Drag 

Reduction

Each time the model applies a technology to a vehicle in the fleet, it considers the next available 

technology on every available path. An available technology is one that is not included in the base 

vehicle, has not been applied by the model, and is not disqualified due to the vehicle’s characteristics 

(discussed below). For a given path, the next available technology is the first available item (if no 

technologies on the path have yet been applied) or the first available item following the most recently 

applied technology on that path. An available path is any path that includes available technologies. 

The engine and transmission paths contain several forks where the model may choose among two or 

more same-path items along with items from other paths. At some of these forks, conditions on the 

connecting arrows require the model to follow a particular branch. These conditions are based on 

previously applied technologies or vehicle characteristics. For example, ladder frame vehicles must 

follow the left branch of the transmission technology path, whereas unibody vehicles can follow either 

the right or left branch. The consequence is that the model considers both aggressive shift logic (ASL) 
V-67 

and CVT for unibody vehicles, but only ASL for ladder frame vehicles. Conditions along the engine 

technologies path are based on valvetrain design (OHV, OHC, SOHC, and DOHC). 

 Other conditions require the model to discontinue considering technologies along a given path. 

For example, 2-Mode Hybrid and Power Split Hybrid drivetrains can be applied only to vehicles 

equipped with automatic transmissions. If the model has already chosen a manual transmission and 

IMA/ISAD/BSG Hybrid drivetrain (or if the base vehicle is equipped with these), the hybrid path 

becomes unavailable and the model must choose subsequent technologies from other paths. 

a. Technology synergies

In some cases, the change in fuel economy achieved by applying a given technology depends 

on what other technologies are already present. The Volpe model has been modified to provide the 

ability to represent such “synergies” between technologies, as discussed above. These effects are 

specified in one of the model’s input files. As shown below in Table V-8, which uses technology 

codes listed in Table V-7 above, most of the synergies represented in the analysis of this proposal are 

negative. In other words, most of the interactions are such that a given technology has a smaller effect 

on fuel economy if some other technologies have already been applied. The inclusion of such effects 

in the model is expected to produce more realistic estimates of the benefit of applying various 

technologies. 
V-68 

Table V-8. "Synergies" from Technology Input File for Volpe Model 

Synergies Synergy Values by Vehicle Class 

Positive values are synergies, negative values are dissynergies. 

Technology A Technology B SUV-Small SUV-Mid SUV-Large Minivan Pickup-Small 

VVTI 5SP -0.50% -0.50% -0.50% -0.50% -0.50%

VVTI ISGO -0.50% -0.50% -0.50% -0.50% -0.50%

VVTC 5SP -0.50% -0.50% -0.50% -0.50% -0.50%

VVTC CVT -0.50% -0.50% -0.50% -0.50% -0.50%

VVTC ASL -0.50% -0.50% -0.50% -0.50% -0.50%

DISP 5SP -1.00% -1.00% -1.00% -1.00% -1.00%

DISP CVT -1.00% -1.00% -1.00% -1.00% -1.00%

DISP ASL -0.50% -0.50% -0.50% -0.50% -0.50%

DISP ISGO -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTC 5SP -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTC CVT -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTC ASL -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTC 6MAN -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTD CVT -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTD 6SP -0.50% -0.50% -0.50% -0.50% -0.50%

DISPO 5SP -1.50% -1.50% -1.50% -1.50% -1.50%

DISPO CVT -1.00% -1.00% -1.00% -1.00% -1.00%

DISPO ASL -0.50% -0.50% -0.50% -0.50% -0.50%

DISPO 6SP -0.50% -0.50% -0.50% -0.50% -0.50%

DISPO ISGO -1.00% -1.00% -1.00% -1.00% -1.00%

VVTO CVT -0.50% -0.50% -0.50% -0.50% -0.50%

VVTO 6MAN 0.50% 0.50% 0.50% 0.50% 0.50%

DOHC 5SP -1.00% -1.00% -1.00% -1.00% -1.00%

DOHC CVT -1.00% -1.00% -1.00% -1.00% -1.00%

DOHC ASL -0.50% -0.50% -0.50% -0.50% -0.50%

DOHC 6SP -0.50% -0.50% -0.50% -0.50% -0.50%

DOHC 6MAN -0.50% -0.50% -0.50% -0.50% -0.50%

DOHC ISGO 0.50% 0.50% 0.50% 0.50% 0.50%

VVLTO 5SP -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTO CVT -0.50% -0.50% -0.50% -0.50% -0.50%

VVLTO 6SP -0.50% -0.50% -0.50% -0.50% -0.50%

 
V-69 

Synergies Synergy Values by Vehicle Class 

Positive values are synergies, negative values are dissynergies. 

Technology A Technology B SUV-Small SUV-Mid SUV-Large Minivan 

PickupSmall 

CVA 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

CVA ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA 6MAN 0.50% 0.50% 0.50% 0.50% 0.50% 

HCCI CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

HCCI 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 5SP -1.00% -1.00% -1.00% -1.00% -1.00% 

TURB CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

TURB ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

ISGO IACC -0.50% -0.50% -0.50% -0.50% -0.50% 

ISGO EPS -1.00% -1.00% -1.00% -1.00% -1.00% 

ISGO 42V -1.00% -1.00% -1.00% -1.00% -1.00% 

DSLT 5SP 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT CVT 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT ASL 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLH 5SP 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLH CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLH 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLH 6MAN 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLH ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLS 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLS CVT -2.50% -2.50% -2.50% -2.50% -2.50% 

DSLS 6SP -1.00% -1.00% -1.00% -1.00% -1.00% 

DSLS 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLS ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 
V-70 

Synergies Synergy Values by Vehicle Class 

Positive values are synergies, negative values are dissynergies. 

Technology A Technology B 

PickupLarge Subcompact Compact Midsize Large 

VVTI 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

VVTI ISGO -0.50% -0.50% -0.50% -0.50% -0.50% 

VVTC 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

VVTC CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

VVTC ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

DISP 5SP -1.00% -1.00% -1.00% -1.00% -1.00% 

DISP CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

DISP ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

DISP ISGO -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTC 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTC CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTC ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTC 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTD CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTD 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DISPO 5SP -1.50% -1.50% -1.50% -1.50% -1.50% 

DISPO CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

DISPO ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

DISPO 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DISPO ISGO -1.00% -1.00% -1.00% -1.00% -1.00% 

VVTO CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

VVTO 6MAN 0.50% 0.50% 0.50% 0.50% 0.50% 

DOHC 5SP -1.00% -1.00% -1.00% -1.00% -1.00% 

DOHC CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

DOHC ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

DOHC 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DOHC 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

DOHC ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

VVLTO 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTO CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

VVLTO 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 
V-71 

Synergies Synergy Values by Vehicle Class 

Positive values are synergies, negative values are dissynergies. 

Technology A Technology B Pickup-Large Subcompact Compact Midsize Large 

CVA 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

CVA ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

CVA 6MAN 0.50% 0.50% 0.50% 0.50% 0.50% 

HCCI CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

HCCI 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 5SP -1.00% -1.00% -1.00% -1.00% -1.00% 

TURB CVT -1.00% -1.00% -1.00% -1.00% -1.00% 

TURB ASL -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

TURB 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

ISGO IACC -0.50% -0.50% -0.50% -0.50% -0.50% 

ISGO EPS -1.00% -1.00% -1.00% -1.00% -1.00% 

ISGO 42V -1.00% -1.00% -1.00% -1.00% -1.00% 

DSLT 5SP 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT CVT 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLT ASL 0.50% 0.00% 0.00% 0.50% 0.50% 

DSLH 5SP 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLH CVT -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLH 6SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLH 6MAN 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLH ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

DSLS 5SP -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLS CVT -2.50% -2.50% -2.50% -2.50% -2.50% 

DSLS 6SP -1.00% -1.00% -1.00% -1.00% -1.00% 

DSLS 6MAN -0.50% -0.50% -0.50% -0.50% -0.50% 

DSLS ISGO 0.50% 0.50% 0.50% 0.50% 0.50% 

b. Technology learning curves

The Volpe model has also been modified to provide the ability to account for cost reductions a 

manufacturer may realize through learning achieved from experience in actually applying a 

given technology. Thus, for some of the technologies, we have included a learning factor. 

Stated another way, the “learning curve” describes the reduction in unit production costs as a 

function of accumulated production volume and small redesigns that reduce costs. 

As explained above, a typical learning curve can be described by three parameters: (1) the initial 

production volume before cost reductions begin to be realized; (2) the rate at which cost 

reductions occur with increases in cumulative production beyond this initial volume (usually 

referred to as the “learning rate”); and (3) the production volume after which costs reach a 
V-72 

“floor,” and further cost reductions no longer occur. Over the region where costs decline with 

accumulating production volume, an experience curve can be expressed as C(Q) = aQ-b, where a

is a constant coefficient, Q represents cumulative production, and b is a coefficient 

corresponding to the assumed learning rate. In turn, the learning rate L, which is usually 

expressed as the percent by which average unit cost declines with a doubling of cumulative 

production, and is related to the value of the coefficient b by L = 100*(1 – 2-b).66

The new learning curves are described in greater detail above in the Proposed Technology 

Assumptions section, III. We seek comment on the new proposed learning curves. 

c. Calibration of reformed CAFE standards

The procedure used by the Volpe model to develop (i.e., calibrate) the initial shape of a reformed 

standard was also modified. In the version of the model used to analyze NHTSA’s April 2006 light 

truck final rule, the asymptotes for the constrained logistic function defining fuel economy targets 

were assigned based on the set of vehicles that would have been assigned to the lowest and highest 

bins defined in that rule’s 2005 NPRM. The Volpe model has been modified to accept specified 

percentages (in terms of either models or sales) of the fleet to include when assigning asymptotes. 

The procedure used by the Volpe model to estimate the “socially optimized” stringency of a reformed 

standard was also modified. In the version of the model used to analyze the 2006 light truck final rule, 

the shape of the function (i.e., the constrained logistic function) defining fuel economy targets was 

recalibrated every model year and then shifted up and down to estimate the stringency at which 

marginal costs begin to exceed marginal benefits or, equivalently, the point at which net societal 

benefits are maximized. However, analysis conducted by the agency to prepare for the current 

rulemaking revealed several opportunities to refine the procedure described above before applying it to 

an action that spans several model years. The first refinement is a method for gradually transforming 

the shape of the continuous function between model years and guarding against erratic fluctuations in 

the shape (though not necessarily the stringency) of the continuous function. The second is the 

implementation of several anti-backsliding measures that prevents the average required CAFE level 

from falling between model years and prevents the continuous function for a given model from 

crossing or falling below that of the preceding model year. The third, applied to passenger cars only, 

is an option to specify a fixed relationship between the function’s midpoint and width coefficients. 

These refinements are discussed in greater detail in Section V.B below. 

6. What manufacturer information does the Volpe model use? 

For purposes of determining and analyzing CAFE standards, NHTSA has historically made 

significant use of detailed product plan information provided to the agency by individual 

manufacturers, supplementing this information where appropriate with information from other 

 

66 See, e.g., Robert H. Williams, “Toward Cost Buydown via Learning-by-Doing for Environmental Energy 

Technologies,” paper presented at Workshop on Learning-by-Doing in Energy Technologies, Resources for the 

Future, Washington, DC, June 17-18, 2003, pp. 1-2. Another common but equivalent formulation of the relationship 

between L and b is (1-L)=2-b, where (1-L) is referred to as the progress ratio; see Richard P. Rumelt, “Note on 

Strategic Cost Dynamics,” POL 2001-1.1, Anderson School of Business, University of California, Los Angeles, 

California, 2001, pp. 4-5. 
V-73 

sources, such as data submitted to the agency in relation to CAFE compliance. Consistent with 

this practice, the Volpe model uses detailed representations of (i.e., model-by-model, linked to 

specific engines and transmissions) the fleets manufacturers are expected to produce for sale in 

the U.S. In preparation for today’s action, the agency issued in the spring of 2006 a request that 

manufacturers provide updated product plans for passenger cars and light trucks. 

NHTSA received product plan information from Chrysler, Ford, GM, Honda, Nissan, 

Mitsubishi, Porsche and Toyota. The agency didn’t receive any product plan information from 

BMW, Ferrari, Hyundai, Mercedes or VW. 

Chrysler, Ford, GM, Honda, Nissan, Mitsubishi, Porsche and Toyota provided information 

covering multiple model years. However, only Chrysler and Mitsubishi provided us with 

product plans that showed differing production quantities, vehicle introductions, vehicle 

redesigns/refreshes changes, without any carryover production quantities, from 2007 to MY 

2015. The agency incorporated their product plan information as part of the input file to the 

model without the need to project or carryover any vehicle production data. 

For the other companies which provided data, the agency carried over production quantities for 

their vehicles, allowing for growth, starting with the year after their product plan data showed 

changes in production quantities or showed the introduction or redesign/refresh of vehicles. 

Product plan information was provided until MY 2013 for Ford and Toyota, thus the first year 

that we started to carry over production quantities for those companies was MY 2014. Product 

plan information was provided until MY 2012 for GM and Nissan, thus the first year that we 

started to carry over production quantities for those companies was MY 2013. Product plan 

information was provided by Honda until MY 2008. Honda asked the agency to carry over those 

plans and also provided data for the last redesign of a vehicle and asked us to carry forward. 

Product plan information was provided until MY 2008 for Porsche, thus the first year that we 

started to carry over production quantities for Porsche was MY 2009. 

For Hyundai, given that it is one of the largest 7 manufacturers, the agency used the mid-year 

2007 data contained in the agency’s CAFE database to establish the baseline models and 

production quantities for their vehicles. For the other manufacturers, because of the time 

constraint the agency was under to meet the statutory deadline, we used the 2005 information 

from our database, which is the latest information used in the current analysis. To the extent 

possible , because, the CAFE database doesn’t capture all of the product plan data that we 

request from companies, we supplemented the CAFE database information with information on 

public websites, from commercial information sources and for Hyundai, from the MY 2008 – 

2011 light truck rule. 

In all cases, manufacturers’ respective sales volumes were normalized to produce passenger car 

and light truck fleets that reflected manufacturers’ MY2006 market shares and to reflect 

passenger car and light truck fleets of projected aggregate volume consistent with forecasts in the 

EIA’s 2007 Annual Energy Outlook. The agency requests comment on whether alternative 

methods should be used to estimate manufacturers’ market shares and the overall sizes of the 

future passenger car and light truck fleets. 
V-74 

In a companion notice, the agency is requesting updated product plan information from all 

companies, and as in previous fuel economy rulemakings, we will be using those plans for the 

final rule. These plans will impact the standards for the final rule. To that end, the agency is 

requesting that these plans be as detailed and as accurate as possible. 

7. What economic information does the Volpe model use? 

NHTSA’s preliminary analysis of alternative CAFE standards for the model years covered by 

this proposed rulemaking relies on a range of information, economic estimates, and input 

parameters. This section describes this information and each assumption and specific parameter 

values, and discusses the rationale for tentatively choosing each one. Similar to the product plan 

information, these economic assumptions play a role in the level of the standards, with some 

having a higher impacts than others. Outside of the cost of technologies and as discussed below, 

the price of gasoline and discount rate used for discounting future benefits account for the 

majority of the impacts. The agency seeks comment on the economic assumptions presented 

below. The agency seeks comment on the economic assumptions presented below. For the 

reader’s reference, Table V-9 below summarizes the values used to calculate the impacts of each 

scenario: 

Table V-9. Economic Values for Benefits Computations (2006$)

Rebound Effect (VMT Elasticity w/respect to Fuel Cost per 

Mile) -0.15 

Discount Rate Applied to Future Benefits 7% 

Payback Period (years) 5.0 

"Gap" between Test and On-Road mpg 20% 

Value of Travel Time per Vehicle ($/hour) $24.00 

Economic Costs of Oil Imports ($/gallon) 

 "Monopsony" Component $0.176 

 Price Shock Component $0.109 

 Military Security Component $ - 

 Total Economic Costs ($/gallon) $0.285 

 Total Economic Costs ($/BBL) $11.97 

External Costs from Additional Automobile Use Due to 

"Rebound" Effect ($/vehicle-mile) 

 Congestion $0.047 

 Accidents $0.025 

 Noise $0.001 

External Costs from Additional Light Truck Use Due to 

"Rebound" Effect ($/vehicle-mile) 

 Congestion $0.052 

 Accidents $0.023 

 Noise $0.001 

Emission Damage Costs 

 Carbon Monoxide ($/ton) $ - 

 Volatile Organic Compounds ($/ton) $1,700 

 Nitrogen Oxides ($/ton) $3,900 
V-75 

 Particulate Matter ($/ton) $164,000 

 Sulfur Dioxide ($/ton) $16,000 

 Carbon Dioxide ($/metric ton) $ 7.00 

 Annual Increase in CO2 Damage Cost 2.4% 

a. Costs of fuel economy technologies 

We developed detailed estimates of the costs of applying fuel economy-improving technologies 

to vehicle models for use in analyzing the impacts of alternative standards considered in this 

rulemaking. The estimates were based on those reported by the 2002 NAS Report analyzing 

costs for increasing fuel economy, but were modified for purposes of this analysis as a result of 

extensive consultations among engineers from NHTSA, EPA, and the Volpe Center. As part of 

this process, the agency also developed varying cost estimates for applying certain fuel economy 

technologies to vehicles of different sizes and body styles. We may adjust these cost estimates 

based on comments received to this NPRM. 

The technology cost estimates used in this analysis are intended to represent manufacturers’ 

direct costs for high-volume production of vehicles with these technologies and sufficient 

experience with their application so that all cost reductions due to “learning curve” effects have 

been fully realized. However, NHTSA recognizes that manufacturers’ actual costs for applying 

these technologies to specific vehicle models are likely to include additional outlays for 

accompanying design or engineering changes to each model, development and testing of 

prototype versions, recalibrating engine operating parameters, and integrating the technology 

with other attributes of the vehicle. Manufacturers may also incur additional corporate overhead, 

marketing, or distribution and selling expenses as a consequence of their efforts to improve the 

fuel economy of individual vehicle models and their overall product lines. 

In order to account for these additional costs, NHTSA applies an indirect cost multiplier of 1.5 to 

the estimate of the vehicle manufacturers’ direct costs for producing or acquiring each fuel 

economy-improving/CO2 emission-reducing technology. Historically, NHTSA has used an 

almost identical multiplier, 1.51, for the markup from variable costs or direct manufacturing 

costs to consumer costs. This markup takes into account fixed costs, burden, manufacturer’s 

profit, and dealers’ profit. NHTSA’s methodology for determining this markup was recently 

peer reviewed.67

This estimate was confirmed by Argonne National Laboratory in a recent review of vehicle 

manufacturers’ indirect costs. The Argonne study was specifically intended to improve the 

accuracy of future cost estimates for production of vehicles that achieve high fuel economy/low 

CO2 emissions by employing many of the same advanced technologies considered in our 

analysis.68 Thus, we believe that its recommendation that a multiplier of 1.5 be applied to direct 

 

67 See Docket No. NHTSA-2007-27454, Item 4. 68 Vyas, Anant, Dan Santini, and Roy Cuenca, Comparison of Indirect Cost Multipliers for Vehicle Manufacturing, 

Center for Transportation Research, Argonne National Laboratory, April 2000. Available at

http://www.transportation.anl.gov/pdfs/TA/57.pdf (last accessed Oct. 23, 2007). 
V-76 

manufacturing costs to reflect manufacturers’ increased indirect costs for deploying advanced 

fuel economy technologies is appropriate for use in the analysis for this rulemaking. 

b. Potential opportunity costs of improved fuel economy 

An important concern is whether achieving the fuel economy improvements required by 

alternative CAFE standards would require manufacturers to compromise the performance, 

carrying capacity, safety, or comfort of their vehicle models. If it did so, the resulting sacrifice 

in the value of these attributes to consumers would represent an additional cost of achieving the 

required improvements in fuel economy, and thus of manufacturers’ compliance with stricter 

CAFE standards. While exact dollar values of these attributes to consumers are difficult to infer 

from vehicle purchase prices, changing vehicle attributes can affect the utility that vehicles 

provide to their owners, and thus their value to potential buyers. 

NHTSA has approached this potential problem by developing tentative cost estimates for fuel 

economy-improving technologies that include any additional manufacturing costs that would be 

necessary to maintain the performance, comfort, capacity, or safety of any light-duty vehicle 

model to which those technologies are applied. In doing so, we primarily followed the precedent 

established by the 2002 NAS Report, although we updated its assumptions as necessary for the 

purposes of the current rulemaking. The NAS study estimated “constant performance and 

utility” costs for fuel economy technologies, and NHTSA has used these as the basis for their 

further efforts to develop the technology costs employed in analyzing manufacturer’s costs for 

complying with alternative light truck standards. 

NHTSA acknowledges the difficulty of estimating technology costs that include costs for the 

accompanying changes in vehicle design that are necessary to maintain performance, capacity, 

and utility. However, we believe that our tentative cost estimates for fuel economy/CO2

emission-reduction technologies should be generally sufficient to prevent significant reductions 

in consumer welfare provided by vehicle models to which manufacturers apply those 

technologies. 

c. The on-road fuel economy “gap” 

Actual fuel economy levels achieved by light-duty vehicles in on-road driving fall somewhat 

short of their levels measured under the laboratory-like test conditions used by EPA to establish 

its published fuel economy ratings for different models. In analyzing the fuel savings from 

alternative CAFE standards, NHTSA has previously adjusted the actual fuel economy 

performance of each light truck model downward from its rated value to reflect the expected size 

of this on-road fuel economy “gap.” On December 27, 2006, EPA adopted changes to its 

regulations on fuel economy labeling, which were intended to bring vehicles’ rated fuel economy 

levels closer to their actual on-road fuel economy levels.69

In its Final Rule, EPA estimated that actual on-road fuel economy for light-duty vehicles 

averages 20 percent lower than published fuel economy levels. For example, if the overall EPA 

fuel economy rating of a light truck is 20 mpg, the on-road fuel economy actually achieved by a 

typical driver of that vehicle is expected to be 16 mpg (20*.80). NHTSA has employed EPA’s 

 

69 71 FR 77871 (Dec. 27, 2006). 
V-77 

revised estimate of this on-road fuel economy gap in its analysis of the fuel savings resulting 

from alternative CAFE standards proposed in this rulemaking.

d. Fuel prices and the value of saving fuel 

Projected future fuel prices are a critical input into the preliminary economic analysis of 

alternative CAFE standards, because they determine the value of fuel savings both to new 

vehicle buyers and to society. NHTSA relied on the most recent fuel price projections from the 

U.S. Energy Information Administration’s (EIA) Annual Energy Outlook (AEO) for this 

analysis. Specifically, we used the AEO 2008 Early Release forecasts of inflation-adjusted 

(constant-dollar) retail gasoline and diesel fuel prices, which represent the EIA’s most up-to-date 

estimate of the most likely course of future prices for petroleum products.70 Federal government 

agencies generally use EIA’s projections in their assessments of future energy-related policies. 

The retail fuel price forecasts presented in AEO 2008 span the period from 2008 through 2030. 

Measured in constant 2006 dollars, the Reference Case forecast of retail gasoline prices during 

calendar year 2020 is $2.30 per gallon, rising gradually to $2.49 by the year 2030. However, 

valuing fuel savings over the 36-year maximum lifetime of light trucks assumed in this analysis 

requires fuel price forecasts that extend through 2050, the last year during which a significant 

number of MY 2015 vehicles will remain in service.71 To obtain fuel price forecasts for the 

years 2031 through 2050, the agency assumes that retail fuel prices forecast in the Reference 

Case for 2030 will remain constant (in 2006 dollars) through 2050. 

The value of fuel savings resulting from improved fuel economy/reduced CO2 emissions to 

buyers of light-duty vehicles is determined by the retail price of fuel, which includes federal, 

state, and any local taxes imposed on fuel sales. Total taxes on gasoline averaged $0.47 per 

gallon during 2006, while those levied on diesel averaged $0.53. State fuel taxes are weighted 

by sales. Because fuel taxes represent transfers of resources from fuel buyers to government 

agencies, however, rather than real resources that are consumed in the process of supplying or 

using fuel, their value must be deducted from retail fuel prices to determine the value of fuel 

savings resulting from more stringent CAFE standards to the U.S. economy as a whole. 

In estimating the economy-wide or “social” value of fuel savings of increasing CAFE/reducing 

CO2 emissions levels, NHTSA assumes that current fuel taxes will remain constant in real or 

inflation-adjusted terms over the lifetimes of the vehicles proposed to be regulated. In effect, 

this assumes that the average value per gallon of taxes on gasoline and diesel fuel levied by all 

levels of government will rise at the rate of inflation over that period. This value is deducted 

from each future year’s forecast of retail gasoline and diesel prices reported in AEO 2008 to 

determine the social value of each gallon of fuel saved during that year as a result of improved 

fuel economy/reduced CO2 emissions. Subtracting fuel taxes results in a projected value for 

saving gasoline of $1.83 per gallon during 2020, rising to $2.02 per gallon by the year 2030. 

 

70 Energy Information Administration, Annual Energy Outlook 2008, Early Release Reference Case Table 12. 

Available at http://www.eia.doe.gov/oiaf/aeo/pdf/aeotab_12.pdf (last accessed Feb. 2, 2008). 71 The agency defines the maximum lifetime of vehicles as the highest age at which more than 2 percent of those 

originally produced during a model year remain in service. In the case of light-duty trucks, for example, this age has 

typically been 36 years for recent model years. 
V-78 

In conducting the preliminary uncertainty analysis of benefits and costs from alternative CAFE 

standards required by OMB, NHTSA also considered higher and lower forecasts of future fuel 

prices. The results of the sensitivity runs can be found in the PRIA. EIA includes “High Price 

Case” and “Low Price Case” in AEO analyses that reflect uncertainties regarding future levels of 

oil production, but those cases are not meant to be probabilistic, and simply illustrate the range of 

uncertainty that exists. Because AEO 2008 Early Release included only a Reference Case of 

forecast of fuel prices and did not include the High and Low Price cases, the agency estimated 

high and low fuel prices corresponding to the AEO 2008 Reference Case forecast by assuming 

that high and low price forecasts would bear the same relationship to the Reference Case forecast 

as reported in AEO 2007.72 These alternative scenarios project retail gasoline prices that range 

from a low of $1.94 per gallon to a high of $3.26 per gallon during 2020, and from $2.03 to 

$3.70 per gallon during 2030. In conjunction with our assumption that fuel taxes will remain 

constant in real or inflation-adjusted terms over this period, these forecasts imply social values of 

saving fuel ranging from $1.47 to $2.79 per gallon during 2020, and from $1.56 to $3.23 per 

gallon in 2030. 

EIA is widely-recognized as an impartial and authoritative source of analysis and forecasts of 

U.S. energy production, consumption, and prices. The agency has published annual forecasts of 

energy prices and consumption levels for the U.S. economy since 1982 in its Annual Energy 

Outlook (AEO), and these forecasts have been widely relied upon by federal agencies for use in 

regulatory analysis and for other purposes. Since 1994, EIA’s annual forecasts have been based 

upon the agency’s National Energy Modeling System (NEMS), which includes detailed 

representation of supply pathways, sources of demand, and their interaction to determine prices 

for different forms of energy. 

From 1982 through 1993, EIA’s forecasts of world oil prices – the primary determinant of prices 

for gasoline, diesel, and other transportation fuels derived from petroleum – consistently 

overestimated actual prices during future years, often very significantly. Of the total of 119 

forecasts of future world oil prices for the years 1985 through 2005 that EIA reported in its 1982-

1993 editions of AEO, 109 overestimated the subsequent actual values for those years, on 

average exceeding their corresponding actual values by 75%. 

Since that time, however, EIA’s forecasts of future world oil prices show a more mixed record 

for accuracy. The 1994-2005 editions of AEO reported 91 separate forecasts of world oil prices 

for the years 1995-2005, of which 33 have subsequently proven too high while the remaining 58 

have underestimated actual prices. The average absolute error (i.e., regardless of its direction) of 

these forecasts has been 21%, but over- and underestimates have tended to offset one another, so 

that on average EIA’s more recent forecasts have underestimated actual world oil prices by 7%. 

Although both its overestimates and underestimates of future world oil prices for recent years 

have often been large, the most recent editions of AEO have significantly underestimated 

petroleum prices during those years for which actual prices are now available. 

 

72 Energy Information Administration, Annual Energy Outlook 2007 High Price Case, Table 12, 

http://www.eia.doe.gov/oiaf/aeo/pdf/aeohptab_12.pdf and Energy Information Administration, Annual Energy 

Outlook 2007 Low Price Case, Table 12, http://www.eia.doe.gov/oiaf/aeo/pdf/aeolptab_12.pdf (last accessed Feb. 2, 

2008). 
V-79 

However, NHTSA does not regard EIA’s recent tendency to underestimate future prices for 

petroleum and refined products or the high level of current fuel prices as adequate justification to 

employ forecasts that differ from the Reference Case forecast presented in EIA’s Annual Energy 

Outlook 2008 Revised Early Release. This is particularly the case because this forecast has been 

revised upward significantly since the initial release of AEO 2008, which in turn represented a 

major upward revision from EIA’s fuel price forecast reported previously in AEO 2007. 

NHTSA also notes that retail gasoline prices across the U.S. have averaged $2.94 per gallon 

(expressed in 2005 dollars) for the first three months of 2008, slightly below EIA’s recently 

revised forecast that gasoline prices will average $2.98 per gallon (also in 2005 dollars) 

throughout 2008. 

Comparing different forecasts of world oil prices also shows that EIA’s Reference Case forecast 

reported in Annual Energy Outlook 2007 (AEO 2007) was actually the highest of all six 

publicly-available forecasts of world oil prices over the 2010-30 time horizon.73 Because world 

petroleum prices are the primary determinant of retail prices for refined petroleum products such 

as transportation fuels, this suggests that the Reference Case forecast of U.S. fuel prices reported 

in AEO 2007 is likely to be the highest of those projected by major forecasting services. Further, 

as indicated above, EIA’s most recent fuel price forecasts have been revised significantly upward 

from those previously projected in AEO 2007. 

e. Consumer valuation of fuel economy and payback period 

In estimating the value of fuel economy improvements that would result from alternative CAFE 

standards to potential vehicle buyers, NHTSA assumes that buyers value the resulting fuel 

savings over only part of the expected lifetime of the vehicles they purchase. Specifically, we 

assume that buyers value fuel savings over the first five years of a new vehicle’s lifetime, and 

that buyers behave as if they do not discount the value of these future fuel savings. The five-year 

figure represents the current average term of consumer loans to finance the purchase of new 

vehicles. We recognize that the period over which individual buyers finance new vehicle 

purchases may not correspond to the time horizons they apply in valuing fuel savings from 

higher fuel economy. However, NHTSA believes that five years represents a reasonable 

estimate of the average period over which buyers who finance their purchases of new vehicle 

receive – and thus must recognize – the monetary value of future fuel savings resulting from 

higher fuel economy.

The value of fuel savings over the first five years of a vehicle model’s lifetime that would result 

under each alternative fuel economy standard is calculated using the projections of retail fuel 

prices described above. It is then deducted from the technology costs incurred by its 

manufacturer to produce the improvement in that model’s fuel economy estimated for each 

alternative standard, to determine the increase in the “effective price” to buyers of that vehicle 

model. The Volpe model uses these estimates of effective costs for increasing the fuel economy 

of each vehicle model to identify the order in which manufacturers would be likely to select 

models for the application of fuel economy-improving technologies in order to comply with 

stricter standards. The average value of the resulting increase in effective cost from each 

 

73 See http://www.eia.doe.gov/oiaf/archive/aeo07/pdf/forecast.pdf, Table 19, p. 106. 
V-80 

manufacturer’s simulated compliance strategy is also used to estimate the impact of alternative 

standards on its total sales for future model years. 

However, it is important to recognize that NHTSA estimates the aggregate value to the U.S. 

economy of fuel savings resulting from alternative standards – or their “social” value – over the 

entire expected lifetimes of vehicles manufactured under those standards, rather than over this 

shorter “payback period” we assume for their buyers. This is discussed directly below in section 

f on “Vehicle survival and use assumptions.” As indicated previously, the maximum vehicle 

lifetimes used to analyze the effects of alternative fuel economy standards are estimated to be 25 

years for automobiles and 36 years for light trucks. 

f. Vehicle survival and use assumptions 

NHTSA’s preliminary analysis of fuel/CO2 emissions savings and related benefits from adopting 

alternative standards for MY 2011-2015 passenger cars and light trucks is based on estimates of 

the resulting changes in fuel use over their entire lifetimes in the U.S. vehicle fleet. The first step 

in estimating lifetime fuel consumption by vehicles produced during a model year is to calculate 

the number that is expected to remain in service during each future year after they are produced 

and sold.74 This number is calculated by multiplying the number of vehicles originally produced 

during a model year by the proportion expected to remain in service at the age they will have 

reached during each subsequent year, often referred to as a “survival rate.” 

The agency relies on projections of the number of passenger cars and light trucks that will be 

produced during future years reported by the EIA in its AEO Reference Case forecast.75 It uses 

updated values of age-specific survival rates for cars and light trucks estimated from yearly 

registration data for vehicles produced during recent model years, to ensure that forecasts of the 

number of vehicles in use reflect recent increases in the durability and expected life spans of cars 

and light trucks.76 

The next step in estimating fuel use is to calculate the total number of miles that the cars and 

light trucks produced in each model year affected by the proposed CAFE standards will be 

driven during each year of their lifetimes. To estimate total miles driven, the number of cars and 

light trucks projected to remain in use during each future year (calculated as described above) is 

 

74 Vehicles are defined to be of age 1 during the calendar year corresponding to the model year in which they are 

produced; thus for example, model year 2000 vehicles are considered to be of age 1 during calendar year 2000, age 

1 during calendar year 2001, and to reach their maximum age of 26 years during calendar year 2025. NHTSA 

considers the maximum lifetime of vehicles to be the age after which less than 2% of the vehicles originally 

produced during a model year remain in service. Applying these conventions to vehicle registration data indicates 

that passenger cars have a maximum age of 26 years, while light trucks have a maximum lifetime of 36 years. See

Lu, S., NHTSA, Regulatory Analysis and Evaluation Division, “Vehicle Survivability and Travel Mileage 

Schedules,” DOT HS 809 952, 8-11 (January 2006). Available at http://www-nrd.nhtsa.dot.gov/pdf/nrd30/NCSA/Rpts/2006/809952.pdf (last accessed Feb. 2, 2008). 75 The most recent edition is Energy Information Administration, Annual Energy Outlook 2008: Early Release. 

Available at http://www.eia.doe.gov/oiaf/aeo/index.html (last accessed Feb. 2, 2008). 76 Lu, S., NHTSA, Regulatory Analysis and Evaluation Division, “Vehicle Survivability and Travel Mileage 

Schedules,” DOT HS 809 952, 8-11 (January 2006). Available at http://www-nrd.nhtsa.dot.gov/pdf/nrd30/NCSA/Rpts/2006/809952.pdf (last accessed Feb. 2, 2008). These updated survival rates suggest that the 

expected lifetimes of recent-model passenger cars and light trucks are 13.8 and 14.5 years. 
V-81 

multiplied by the average number of miles they are expected to be driven at the age they will 

have reached in that year. The agency estimated the average number of miles driven annually by 

cars and light trucks of each age using data from the Federal Highway Administration’s 2001 

National Household Transportation Survey (NHTS).77 

Finally, fuel consumption during each year of a model year’s lifetime is estimated by dividing 

the total number of miles its surviving vehicles are driven by the fuel economy they are expected 

to achieve under each alternative CAFE standard. Each model year’s total lifetime fuel 

consumption is the sum of fuel use by the cars or light trucks produced during that model year 

that are projected to remain in use during each year of their maximum life spans. In turn, the 

savings in a model year’s lifetime fuel use that will result from each alternative CAFE standard 

is the difference between its lifetime fuel use at the fuel economy level it attains under the 

Baseline alternative, and its lifetime fuel use at the higher fuel economy level it is projected to 

achieve under that alternative standard. 

To illustrate these calculations, the most recent edition of the AEO projections that 8.52 million 

light trucks will be produced during 2012, and the agency’s updated survival rates show that 

slightly more than half of these – 50.1 percent, or 4.27 million – are projected to remain in 

service during the year 2027, when they will have reached an age of 14 years. At that age, light 

trucks achieving the fuel economy level required under the Baseline alternative are driven an 

average of about 10,400 miles, so model year 2012 light trucks will be driven a total of 44.4 

billion miles (= 4.27 million surviving vehicles x 10,400 miles per vehicle) during 2027. 

Summing the results of similar calculations for each year of their 36-year maximum lifetime, 

model year 2012 light trucks will be driven a total of 1,502 billion miles under the Baseline 

alternative. Under that alternative, they are projected to achieve a test fuel economy level of 

23.8 mpg, which corresponds to actual on-road fuel economy of 19.0 mpg (= 23.8 mpg x 80%). 

Thus their lifetime fuel use under the Baseline alternative is projected to be 79.0 billion gallons 

(= 1,502 billion miles divided by 19.0 miles per gallon). 

g. Growth in total vehicle use

By assuming that the annual number of miles driven by cars and light trucks at any age will 

remain constant over the future, NHTSA’s procedure for estimating the number of miles driven 

by cars and light trucks over their lifetimes in effect assumes that all future growth in total 

vehicle-miles driven stems from increases in the number of vehicles in service, rather than from 

increases in the average number of miles they are driven each year. Similarly, because the 

survival rates used to estimate the number of cars and light trucks remaining in service to various 

ages are assumed to remain fixed for future model years, growth in the total number of cars and 

light trucks in use is effectively assumed to result only from increasing sales of new vehicles. In 

order to determine the validity of these assumptions, the agency conducted a detailed analysis of 

the causes of recent growth in car and light truck use. 

From 1985 through 2005, the total number of miles driven (usually referred to as vehicle-miles 

traveled, or VMT) by passenger cars increased 35 percent, equivalent to a compound annual 

 

77 For a description of the Survey, see http://nhts.ornl.gov/quickStart.shtml (last accessed Dec. 3, 2007). 
V-82 

growth rate of 1.5 percent.78 During that time, the total number of passenger cars registered for 

in the U.S. grew by about 0.3 percent annually, almost exclusively as a result of increasing sales 

of new cars.79 Thus growth in the average number of miles automobiles are driven each year 

accounted for the remaining 1.2 percent (= 1.5% - 0.3%) annual growth in total automobile use.80 

Over this same period, total VMT by light trucks increased much faster, growing at an annual 

rate of 5.1 percent. In contrast to the causes of growth in automobile use, however, nearly all 

growth in light truck use over these two decades was attributable to rapid increases in the number

of light trucks in use.81 In turn, growth in the size of the nation’s light truck fleet has resulted 

almost exclusively from rising sales of new light trucks, since the fraction of new light trucks 

remaining in service to various ages has remained stable or even declined slightly over the past 

two decades.82 

On the basis of this analysis, the agency tentatively concludes that its projections of future 

growth in light truck VMT account fully for the primary cause of its recent growth, which has 

been the rapid increase in sales of new light trucks during recent model years. However, the 

assumption that average annual use of passenger cars will remain fixed over the future appears to 

ignore an important source of recent growth in their total use, the gradual increase in the average 

number of miles they are driven. To the extent that this factor continues to represent a 

significant source of growth in future passenger car use, the agency’s analysis is likely to 

underestimate the reductions in fuel use and related environmental impacts resulting from stricter 

CAFE standards for passenger cars.83 The agency plans to account explicitly for potential future 

growth in average annual use of both cars and light trucks in the analysis accompanying its Final 

Rule establishing CAFE standards for model years 2011-15. 

h. Accounting for the rebound effect of higher fuel economy 

 

78 Calculated from data reported in FHWA, Highway Statistics, Summary to 1995, Table vm201at 

http://www.fhwa.dot.gov/ohim/summary95/vm201a.xlw, and annual editions 1996-2005, Table VM-1 at 

http://www.fhwa.dot.gov/policy/ohpi/hss/hsspubs.htm (last accessed Feb. 2, 2008). 79 A slight increase in the fraction of new passenger cars remaining in service beyond age 10 has accounted for a 

small share of growth in the U.S. automobile fleet. The fraction of new automobiles remaining in service to various 

ages was computed from R.L. Polk vehicle registration data for 1977 through 2005 by the agency’s Center for 

Statistical Analysis. 

80 See supra note [2 above here] 81 FHWA data show that growth in total miles driven by “Two-axle, four-tire trucks,” a category that includes most 

or all light trucks used as passenger vehicles, averaged 5.1% annually from 1985 through 2005. However, the 

number of miles light trucks are driven each year averaged 11,114 during 2005, almost unchanged from the average 

figure of 11,016 miles during 1985. Id. 82 Unpublished analysis of R.L. Polk vehicle registration data conducted by NHTSA Center for Statistical Analysis, 

2005. 

83 Assuming that average annual miles driven per automobile will continue to increase over the future would 

increase the agency’s estimates of total lifetime mileage for MY 2011-18 passenger cars. Their estimated lifetime 

fuel use would also increase under each alternative standard considered in this analysis, but in inverse relation to 

their fuel economy. Thus lifetime fuel use will increase by more under the No Increase alternative than under any of 

the alternatives that would increase passenger car CAFE standards, and by progressively less for the alternatives that 

impose stricter standards. Taking account of this factor would thus increase the agency’s estimates of fuel savings 

for those alternatives, and omitting it will cause the agency’s analysis to underestimate those fuel savings. 
V-83 

The rebound effect refers to the tendency for owners to increase the number of miles they drive a 

vehicle in response to an increase in its fuel economy, as would result from more stringent fuel 

economy standards. The rebound effect occurs because an increase in a vehicle’s fuel economy 

reduces its owner’s fuel cost for driving each mile, which is typically the largest single 

component of the cost of operating a vehicle. Even with the vehicle’s higher fuel economy, this 

additional driving uses some fuel, so the rebound effect will reduce the net fuel savings that 

result when the fuel economy standards require manufacturers to increase fuel economy. The 

rebound effect is usually expressed as the percentage by which annual vehicle use increases 

when average fuel cost per mile driven decreases in response to a change in the marginal cost of 

driving an extra mile, due either an increase in fuel economy or a reduction in the price of fuel. 

The magnitude of the rebound effect is one of the determinants of the actual fuel savings that are 

likely to result from adopting stricter standards, and thus an important parameter affecting 

NHTSA’s evaluation of alternative standards for future model years. The rebound effect can be 

measured directly by estimating the elasticity of vehicle use with respect to fuel economy itself, 

or indirectly by the elasticity of vehicle use with respect to fuel cost per mile driven.84 When 

expressed as a positive percentage, either of these parameters gives the fraction of fuel savings 

that would otherwise result from adopting stricter standards, but is offset by the increase in fuel 

consumption that results when vehicles with increased fuel economy are driven more. 

Research on the magnitude of the rebound effect in light-duty vehicle use dates to the early 

1980s, and almost unanimously concludes that a statistically significant rebound effect occurs 

when vehicle fuel efficiency improves.85 The most common approach to estimating its 

magnitude has been to analyze statistically household survey data on vehicle use, fuel 

consumption, fuel prices (often obtained from external sources), and other determinants of 

household travel demand to isolate the response of vehicle use to higher fuel economy. Other 

studies have relied on econometric analysis of annual U.S. data on vehicle use, fuel economy, 

fuel prices, and other variables to identify the response of total or average vehicle use to changes 

in fleet-wide average fuel economy and its effect of fuel cost per mile driven. Two recent studies 

analyzed yearly variation in vehicle ownership and use, fuel prices, and fuel economy among 

individual states over an extended time period in order to measure the response of vehicle use to 

changing fuel economy.86 

An important distinction among studies of the rebound effect is whether they assume that the 

effect is constant, or varies over time in response to the absolute levels of fuel costs, personal 

income, or household vehicle ownership. Most studies using aggregate annual data for the U.S. 

assume a constant rebound effect, although some of these studies test whether the effect can vary 

as changes in retail fuel prices or average fuel economy alter fuel cost per mile driven. Many 

 

84 Fuel cost per mile is equal to the price of fuel in dollars per gallon divided by fuel economy in miles per gallon, so 

this figure declines when a vehicle’s fuel economy increases. 

85 Some studies estimate that the long-run rebound effect is significantly larger than the immediate response to 

increased fuel efficiency. Although their estimates of the adjustment period required for the rebound effect to reach 

its long-run magnitude vary, this long-run effect is most appropriate for evaluating the fuel savings and emissions 

reductions resulting from stricter standards that would apply to future model years. 

86 In effect, these studies treat U.S. states as a data “panel” by applying appropriate estimation procedures to data 

consisting of each year’s average values of these variables for the separate states. 
V-84 

studies using household survey data estimate significantly different rebound effects for 

households owning varying numbers of vehicles, although they arrive at differing conclusions 

about whether the rebound effect is larger among households that own more vehicles. One 

recent study using state-level data concludes that the rebound effect varies directly in response to 

changes in personal income and the degree of urbanization of U.S. cities, as well as fuel costs. 

In order to arrive at a preliminary estimate of the rebound effect for use in assessing the fuel 

savings, emissions reductions, and other impacts of alternative standards, NHTSA reviewed 22 

studies of the rebound effect conducted from 1983 through 2005. We then conducted a detailed 

analysis of the 66 separate estimates of the long-run rebound effect reported in these studies, 

which is summarized in the table below.87 As the table indicates, these 66 estimates of the longrun rebound effect range from as low as 7 percent to as high as 75 percent, with a mean value of 

23 percent. 

Limiting the sample to 50 estimates reported in the 17 published studies of the rebound effect 

yields the same range but a slightly higher mean (24 percent), while focusing on the authors’ 

preferred estimates from published studies narrows this range and lowers its average only 

slightly. The median estimate of the rebound effect in all three samples, which is generally 

regarded as a more reliable indicator of their central tendency than the average because it is less 

influenced by unusually small and large estimates, is 22 percent. As Table V-10 indicates, 

approximately two-thirds of all estimates reviewed, of all published estimates, and of authors’ 

preferred estimates fall in the range of 10-30 percent. 

Table V-10. Summary of Rebound Effect Estimates 

Category of Estimates Number of Range Distribution 

Studies 

Number of 

Estimates 

Low High Median Mean Std. Dev.

All Estimates 22 66 7% 75% 22% 23% 14% 

Published Estimates 17 50 7% 75% 22% 24% 14% 

Authors' Preferred Estimates 17 17 9% 75% 22% 22% 15% 

U.S. Time-Series Estimates 7 34 7% 45% 14% 18% 9% 

Household Survey Estimates 13 23 9% 75% 31% 31% 16% 

Pooled U.S. State Estimates 2 9 8% 58% 22% 25% 14% 

Constant Rebound Effect (1) 15 37 7% 75% 20% 23% 16% 

Variable Rebound Effect: (1) 

Reported Estimates 10 29 10% 45% 23% 23% 10% 

Updated to 2006 (2) 10 29 6% 46% 16% 19% 12% 

(1) Three studies estimate both constant and variable rebound effects. 

(2) Reported estimates updated to reflect 2006 values of vehicle use, fuel prices, fleet 

fuel efficiency, household income, and household vehicle ownership. 

 

87 In some cases, NHTSA derived estimates of the overall rebound effect from more detailed results reported in the 

studies. For example, where studies estimated different rebound effects for households owning different numbers 

of vehicles but did not report an overall value, we computed a weighted average of the reported values using the 

distribution of households among vehicle ownership categories. 
V-85 

The type of data used and authors’ assumption about whether the rebound effect varies over time 

have important effects on its estimated magnitude. The 34 estimates derived from analysis of 

U.S. annual time-series data produce a median estimate of 14 percent for the long-run rebound 

effect, while the median of 23 estimates based on household survey data is more than twice as 

large (31 percent), and the median of 9 estimates based on pooled state data matches that of the 

entire sample (22 percent). The 37 estimates assuming a constant rebound effect produce a 

median of 20 percent, while the 29 originally reported estimates of a variable rebound effect 

have a slightly higher median value (23 percent). 

In selecting a single value for the rebound effect to use in analyzing alternative standards for 

future model years, NHTSA tentatively attaches greater significance to studies that allow the 

rebound effect to vary in response to changes in the various factors that have been found to affect 

its magnitude. However, it is also important to update authors’ originally-reported estimates of 

variable rebound effects to reflect current conditions. Recalculating the 29 original estimates of 

variable rebound effects to reflect current (2006) values for retail fuel prices, average fuel 

economy, personal income, and household vehicle ownership reduces their median estimate to 

16 percent.88 NHTSA also tentatively attaches greater significance to the recent study by Small 

and Van Dender (2005), which finds that the rebound effect tends to decline as average fuel 

economy, personal income, and suburbanization of U.S. cities increase, but – in accordance with 

previous studies – rises with increasing fuel prices.89

Considering the empirical evidence on the rebound effect as a whole, but according greater 

importance to the updated estimates from studies allowing the rebound effect to vary – 

particularly the Small and Van Dender study – NHTSA has selected a rebound effect of 15 

percent to evaluate the fuel savings and other effects of alternative standards for the time period 

covered by this rulemaking. However, we do not believe that evidence of the rebound effect’s 

dependence on fuel prices or household income is sufficiently convincing to justify allowing its 

future value to vary in response to forecast changes in these variables. A range extending from 

10 percent to at least 20 percent -- and perhaps as high as 25 percent -- appears to be appropriate 

 

88 As an illustration, Small and Van Dender (2005) allow the rebound effect to vary over time in response to 

changes in real per capita income as well as average fuel cost per mile driven. While their estimate for the entire 

interval (1966-2001) they analyze is 22 percent, updating this estimate using 2006 values of these variables reduces 

the rebound effect to approximately 10 percent. Similarly, updating Greene’s 1992 original estimate of a 15 percent 

rebound effect to reflect 2006 fuel prices and average fuel economy reduces it to 6 percent. See David L. Greene, 

“Vehicle Use and Fuel Economy: How Big is the Rebound Effect?” The Energy Journal, 13:1 (1992), 117-143. In 

contrast, the distribution of households among vehicle ownership categories in the data samples used by Hensher et 

al. (1990) and Greene et al. (1999) are nearly identical to the most recent estimates for the U.S., so updating their 

original estimates to current U.S. conditions changes them very little. See David A. Hensher, Frank W. Milthorpe, 

and Nariida C. Smith, “The Demand for Vehicle Use in the Urban Household Sector: Theory and Empirical 

Evidence,” Journal of Transport Economics and Policy, 24:2 (1990), 119-137; and David L. Greene, James R. Kahn, 

and Robert C. Gibson, “Fuel Economy Rebound Effect for Household Vehicles,” The Energy Journal, 20:3 (1999), 

1-21. 

89 In the most recent light truck CAFE rulemaking, NHTSA chose not to preference the Small and Van Dender study 

over other published estimates of the value of the rebound effect, stating that since it “remains an unpublished 

working paper that has not been subjected to formal peer review, ...the agency does not yet consider the estimates it 

provides to have the same credibility as the published and widely-cited estimates it relied upon.” See 71 FR 17633 

(Apr. 6, 2006). The study has subsequently been published and peer-reviewed, so NHTSA is now prepared to 

“consider it in developing its own estimate of the rebound effect for use in subsequent CAFE rulemakings.” 
V-86 

for the required analysis of the uncertainty surrounding these estimates. While the agency 

selected 15 percent, it also ran sensitivity analyses at 10 and 20 percent. The results are shown in 

the uncertainties analysis. 

i. Benefits from increased vehicle use 

The increase in vehicle use from the rebound effect provides additional benefits to their owners, 

who may make more frequent trips or travel farther to reach more desirable destinations. This 

additional travel provides benefits to drivers and their passengers by improving their access to 

social and economic opportunities away from home. As evidenced by their decisions to make 

more frequent or longer trips when improved fuel economy reduces their costs for driving, the 

benefits from this additional travel exceed the costs drivers and passengers incur in making more 

frequent or longer trips. 

The amount by which the benefits from this additional travel exceed its costs (for fuel and other 

operating expenses) measures the net benefits that drivers receive from the additional travel, 

usually referred to as increased consumer surplus. NHTSA’s analysis estimates the economic 

value of the increased consumer surplus provided by added driving using the conventional 

approximation, which is one half of the product of the decline in vehicle operating costs per 

vehicle-mile and the resulting increase in the annual number of miles driven. The magnitude of 

these benefits represents a small fraction of the total benefits from the alternative fuel economy 

standards considered. 

j. Added costs from congestion, crashes and noise 

Although it provides some benefits to drivers, increased vehicle use associated with the rebound 

effect also contributes to increased traffic congestion, motor vehicle accidents, and highway 

noise. Depending on how the additional travel is distributed over the day and on where it takes 

place, additional vehicle use can contribute to traffic congestion and delays by increasing traffic 

volumes on facilities that are already heavily traveled during peak periods. These added delays 

impose higher costs on drivers and other vehicle occupants in the form of increased travel time 

and operating expenses. Because drivers do not take these added costs into account in deciding 

when and where to travel, they must be accounted for separately as a cost of the added driving 

associated with the rebound effect. 

Increased vehicle use due to the rebound effect may also increase the costs associated with traffic 

accidents. Drivers may take account of the potential costs they (and their passengers) face from 

the possibility of being involved in an accident when they decide to make additional trips. 

However, they probably do not consider all of the potential costs they impose on occupants of 

other vehicles and on pedestrians when accidents occur, so any increase in these “external” 

accident costs must be considered as another cost of additional rebound-effect driving. Like 

increased delay costs, any increase in these external accident costs caused by added driving is 

likely to depend on the traffic conditions under which it takes place, since accidents are more 

frequent in heavier traffic (although their severity may be reduced by the slower speeds at which 

heavier traffic typically moves). 
V-87 

Finally, added vehicle use from the rebound effect may also increase traffic noise. Noise 

generated by vehicles causes inconvenience, irritation, and potentially even discomfort to 

occupants of other vehicles, to pedestrians and other bystanders, and to residents or occupants of 

surrounding property. Because these effects are unlikely to be taken into account by the drivers 

whose vehicles contribute to traffic noise, they represent additional externalities associated with 

motor vehicle use. Although there is considerable uncertainty in measuring their value, any 

increase in the economic costs of traffic noise resulting from added vehicle use must be included 

together with other increased external costs from the rebound effect. 

NHTSA relies on estimates of congestion, accident, and noise costs caused by automobiles and 

light trucks developed by the Federal Highway Administration to estimate the increased external 

costs caused by added driving due to the rebound effect.90 These estimates are intended to 

measure the increases in costs from added congestion, property damages and injuries in traffic 

accidents, and noise levels caused by automobiles and light trucks that are borne by persons 

other than their drivers (or “marginal” external costs). Updated to 2006 dollars, FHWA’s 

“Middle” estimates for marginal congestion, accident, and noise costs caused by automobile use 

amount to 5.2 cents, 2.3 cents, and 0.1 cents per vehicle-mile (for a total of 7.6 cents per mile), 

while those for pickup trucks and vans are 4.7 cents, 2.5 cents, and 0.1 cents per vehicle-mile 

(for a total of 7.3 cents per mile).91, 92 These costs are multiplied by the annual increases in 

automobile and light truck use from the rebound effect to yield the estimated increases in 

congestion, accident, and noise externality costs during each future year. 

k. Petroleum consumption and import externalities 

U.S. consumption and imports of petroleum products also impose costs on the domestic 

economy that are not reflected in the market price for crude petroleum, or in the prices paid by 

consumers of petroleum products such as gasoline. In economics literature on this subject, these 

costs include (1) higher prices for petroleum products resulting from the effect of U.S. oil import 

demand on the world oil price; (2) the risk of disruptions to the U.S. economy caused by sudden 

reductions in the supply of imported oil to the U.S.; and (3) expenses for maintaining a U.S. 

military presence to secure imported oil supplies from unstable regions, and for maintaining the 

strategic petroleum reserve (SPR) to cushion against resulting price increases.93 Higher U.S. 

imports of crude oil or refined petroleum products increase the magnitude of these external 

 

90 These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study; see

http://www.fhwa.dot.gov/policy/hcas/final/index.htm (last accessed Dec. 3, 2007). 

91 See Federal Highway Administration, 1997 Federal Highway Cost Allocation Study, 

http://www.fhwa.dot.gov/policy/hcas/final/index.htm, Tables V-22, V-23, and V-24 (last accessed Dec. 3, 2007). 

92 The Federal Highway Administration’s estimates of these costs agree closely with some other recent estimates. 

For example, recent published research conducted by Resources for the Future (RFF) estimates marginal congestion 

and external accident costs for increased light-duty vehicle use in the U.S. to be 3.5 and 3.0 cents per vehicle-mile in 

year-2002 dollars. See Ian W.H. Parry and Kenneth A. Small, “Does Britain or the U.S. Have the Right Gasoline 

Tax?” Discussion Paper 02-12, Resources for the Future, 19 and Table 1 (March 2002). Available at

http://www.rff.org/rff/Documents/RFF-DP-02-12.pdf (last accessed October 20, 2007). 

93 See, e.g., Bohi, Douglas R. and W. David Montgomery (1982). Oil Prices, Energy Security, and Import Policy 

Washington, DC: Resources for the Future, Johns Hopkins University Press; Bohi, D. R., and M. A. Toman (1993). 

"Energy and Security: Externalities and Policies," Energy Policy 21:1093-1109; and Toman, M. A. (1993). "The 

Economics of Energy Security: Theory, Evidence, Policy," in A. V. Kneese and J. L. Sweeney, eds. (1993). 

Handbook of Natural Resource and Energy Economics, Vol. III. Amsterdam: North-Holland, pp. 1167-1218. 
V-88 

economic costs, thus increasing the true economic cost of supplying transportation fuels above 

the resource costs of producing them. Conversely, reducing U.S. imports of crude petroleum or 

refined fuels or reducing fuel consumption can reduce these external costs. Any reduction in 

their total value that results from improved light truck fuel economy represents an economic 

benefit of setting more stringent CAFE standards in addition to the value of fuel savings and 

emissions reductions itself. 

Increased U.S. oil imports can impose higher costs on all purchasers of petroleum products, 

because the U.S. is a sufficiently large purchaser of foreign oil supplies that changes in U.S. 

demand can affect the world price. The effect of U.S. petroleum imports on world oil prices is 

determined by the degree of OPEC monopoly power over global oil supplies, and the degree of 

monopsony power over world oil demand exerted by the U.S. The combination of these two 

factors means that increases in domestic demand for petroleum products that are met through 

higher oil imports can cause the price of oil in the world market to rise, which imposes economic 

costs on all other purchasers in the global petroleum market in excess of the higher prices paid 

by U.S. consumers.94 Conversely, reducing U.S. oil imports can lower the world petroleum 

price, and thus generate benefits to other oil purchasers by reducing these “monopsony costs.” 

Although the degree of current OPEC monopoly power is subject to debate, the consensus 

appears to be that OPEC remains able to exercise some degree of control over the response of 

world oil supplies to variation in world oil prices, so that the world oil market does not behave 

completely competitively.95 The extent of U.S. monopsony power is determined by a complex 

set of factors including the relative importance of U.S. imports in the world oil market, and the 

sensitivity of petroleum supply and demand to its world price among other participants in the 

international oil market. Most evidence appears to suggest that variation in U.S. demand for 

imported petroleum continues to exert some influence on world oil prices, although this 

influence appears to be limited.96 

The second component of external economic costs imposed by U.S. petroleum imports arises 

partly because an increase in oil prices triggered by a disruption in the supply of imported oil 

reduces the level of output that the U.S. economy can produce. The reduction in potential U.S. 

economic output depends on the extent and duration of the increases in petroleum product prices 

that result from a disruption in the supply of imported oil, as well as on whether and how rapidly 

these prices return to pre-disruption levels. Even if prices for imported oil return completely to 

their original levels, however, economic output will be at least temporarily reduced from the 

level that would have been possible without a disruption in oil supplies. 

 

94 For example, if the U.S. imports 10 million barrels of petroleum per day at a world oil price of $20 per barrel, its 

total daily import bill is $200 million. If increasing imports to 11 million barrels per day causes the world oil price 

to rise to $21 per barrel, the daily U.S. import bill rises to $231 million. The resulting increase of $31 million per 

day ($231 million minus $200 million) is attributable to increasing daily imports by only 1 million barrels. This 

means that the incremental cost of importing each additional barrel is $31, or $10 more than the newly-increased 

world price of $21 per barrel. This additional $10 per barrel represents a cost imposed on all other purchasers in the 

global petroleum market by U.S. buyers, in excess of the price they pay to obtain those additional imports. 

95 For a summary see Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An 

Assessment of Benefits and Costs, ORNL-6851, Oak Ridge National Laboratory, November 1, 1997, 17. Available 

at http://dmses.dot.gov/docimages/pdf93/343894_web.pdf (last accessed Dec. 2, 2007). 96 Id., 18-19. 
V-89 

Because supply disruptions and resulting price increases tend to occur suddenly rather than 

gradually, they can also impose costs on businesses and households for adjusting their use of 

petroleum products more rapidly than if the same price increase had occurred gradually over 

time. These adjustments impose costs because they temporarily reduce economic output even 

below the level that would ultimately be reached once the U.S. economy completely adapted to 

higher petroleum prices. The additional costs to businesses and households reflect their inability 

to adjust prices, output levels, and their use of energy and other resources quickly and smoothly 

in response to rapid changes in prices for petroleum products. 

Since future disruptions in foreign oil supplies are an uncertain prospect, each of these disruption 

costs must be adjusted by the probability that the supply of imported oil to the U.S. will actually 

be disrupted. The “expected value” of these costs – the product of the probability that an oil 

import disruption will occur and the costs of reduced economic output and abrupt adjustment to 

sharply higher petroleum prices – is the appropriate measure of their magnitude. Any reduction 

in these expected disruption costs resulting from a measure that lowers U.S. oil imports 

represents an additional economic benefit beyond the direct value of savings from reduced 

purchases of petroleum products. 

While the vulnerability of the U.S. economy to oil price shocks is widely thought to depend on 

total petroleum consumption rather than on the level of oil imports, variation in imports is still 

likely to have some effect on the magnitude of price increases resulting from a disruption of 

import supply. In addition, changing the quantity of petroleum imported into the U.S. may also 

affect the probability that such a disruption will occur. If either the size of the likely price 

increase or the probability that U.S. oil supplies will be disrupted is affected by oil imports, the 

expected value of the costs from a supply disruption will also depend on the level of imports. 

Businesses and households use a variety of market mechanisms, including oil futures markets, 

energy conservation measures, and technologies that permit rapid fuel switching to “insure” 

against higher petroleum prices and reduce their costs for adjusting to sudden price increases. 

While the availability of these market mechanisms has likely reduced the potential costs of 

disruptions to the supply of imported oil, consumers of petroleum products are unlikely to take 

account of costs they impose on others, so these costs are probably not reflected in the price of 

imported oil. Thus changes in oil import levels probably continue to affect the expected cost to 

the U.S. economy from potential oil supply disruptions, although this component of oil import 

costs is likely to be significantly smaller than estimated by studies conducted in the wake of the 

oil supply disruptions during the 1970s. 

The third component of the external economic costs of importing oil into the U.S. includes 

government outlays for maintaining a military presence to secure the supply of oil imports from 

potentially unstable regions of the world and to protect against their interruption. Some analysts 

also include outlays for maintaining the U.S. Strategic Petroleum Reserve (SPR), which is 

intended to cushion the U.S. economy against the consequences of disruption in the supply of 

imported oil, as additional costs of protecting the U.S. economy from oil supply disruptions. 
V-90 

NHTSA believes that while costs for U.S. military security may vary over time in response to 

long-term changes in the actual level of oil imports into the U.S., these costs are unlikely to 

decline in response to any reduction in U.S. oil imports resulting from raising future CAFE 

standards for passenger cars and light trucks. U.S. military activities in regions that represent 

vital sources of oil imports also serve a broader range of security and foreign policy objectives 

than simply protecting oil supplies, and as a consequence are unlikely to vary significantly in 

response to changes in the level of oil imports prompted by higher standards. 

Similarly, while the optimal size of the SPR from the standpoint of its potential influence on 

domestic oil prices during a supply disruption may be related to the level of U.S. oil consumption 

and imports, its actual size has not appeared to vary in response to recent changes in oil imports. 

Thus while the budgetary costs for maintaining the Reserve are similar to other external costs in 

that they are not likely to be reflected in the market price for imported oil, these costs do not 

appear to have varied in response to changes in oil import levels. 

In analyzing benefits from its recent actions to increase light truck CAFE standards for model 

years 2005-07 and 2008-11, NHTSA relied on a 1997 study by Oak Ridge National Laboratory 

(ORNL) to estimate the value of reduced economic externalities from petroleum consumption 

and imports.97 More recently, ORNL updated its estimates of the value of these externalities, 

using the analytic framework developed in its original 1997 study in conjunction with recent 

estimates of the variables and parameters that determine their value.98 These include world oil 

prices, current and anticipated future levels of OPEC petroleum production, U.S. oil import 

levels, the estimated responsiveness of oil supplies and demands to prices in different regions of 

the world, and the likelihood of oil supply disruptions. ORNL prepared its updated estimates of 

oil import externalities for use by EPA in evaluating the benefits of reductions in U.S. oil 

consumption and imports expected to result from its Renewable Fuel Standard Rule of 2007 

(RFS).99 

The updated ORNL study was subjected to a detailed peer review by experts selected by EPA, 

and its estimates of the value of oil import externalities were subsequently revised to reflect their 

comments and recommendations.100 Specifically, reviewers recommended that ORNL increase 

its estimates of the sensitivity of oil supply by non-OPEC producers and oil demand by nations 

other than the U.S. to changes in the world oil price, as well as reduce its estimate of the 

sensitivity of U.S. gross domestic product (GDP) to potential sudden increases in world oil 

prices. 

After making the revisions recommended by peer reviewers, ORNL’s updated estimates of the 

monopsony cost associated with U.S. oil imports range from $5.22 to $9.68 per barrel, with a 

 

97 Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An Assessment of Benefits and 

Costs, ORNL-6851, Oak Ridge National Laboratory, November 1, 1997. Available at

http://dmses.dot.gov/docimages/pdf93/343894_web.pdf (last accessed Dec. 2, 2007). 

98 Leiby, Paul N. "Estimating the Energy Security Benefits of Reduced U.S. Oil Imports," Oak Ridge National 

Laboratory, ORNL/TM-2007/028, Revised July 23, 2007. Available at http://pzl1.ed.ornl.gov/energysecurity.html 

(click on link below “Oil Imports Costs and Benefits”) (last accessed Sept. 10, 2007). 99 72 FR 23899 (May 1, 2007). 

100 Peer Review Report Summary: Estimating the Energy Security Benefits of Reduced U.S. Oil Imports, 

ICF, Inc., September 2007. 
V-91 

most likely estimate of $7.41 per barrel. These estimates imply that each gallon of fuel saved as 

a result of adopting higher CAFE standards will reduce the monopsony costs of U.S. oil imports 

by $0.124 to $0.230 per gallon, with the actual value most likely to be $0.176 per gallon saved. 

ORNL’s updated and revised estimates of the increase in the expected costs associated with oil 

supply disruptions to the U.S. and the resulting rapid increase in prices for petroleum products 

amount to $4.54 to $5.84 per barrel, although its most likely estimate of $4.59 per barrel is very 

close to the lower end of this range. According to these estimates, each gallon of fuel saved will 

reduce the expected costs disruptions to the U.S. economy by $0.108 to $0.139, with the actual 

value most likely to be $0.109 per gallon. 

The updated and revised ORNL estimates suggest that the combined reduction in monopsony 

costs and expected costs to the U.S. economy from oil supply disruptions resulting from lower 

fuel consumption total $0.232 to $0.370 per gallon, with a most likely estimate of $0.286 per 

gallon. This represents the additional economic benefit likely to result from each gallon of fuel 

saved by higher CAFE standards, beyond the savings in resource costs for producing and 

distributing each gallon of fuel saved. NHTSA employs this midpoint estimate in its analysis of 

the benefits from fuel savings projected to result from alternative CAFE standards for model 

years 2011-15. It also analyzes the effect on these benefits estimates from variation in this value 

over the range from $0.232 to $0.370 per gallon of fuel saved. 

NHTSA’s analysis of benefits from alternative CAFE standards does not include cost savings 

from either reduced outlays for U.S. military operations or maintaining a smaller SPR among the 

external benefits of reducing gasoline consumption and petroleum imports by means of 

tightening future standards. This view concurs with that of both the original ORNL study of 

economic costs from U.S. oil imports and its recent update, which conclude that savings in 

government outlays for these purposes are unlikely to result form reductions in consumption of 

petroleum products and oil imports on the scale of those likely to result from the alternative 

increases in CAFE standards considered for model years 2011-15. 

l. Air pollutant emissions 

(i) Impacts on criteria air pollutant emissions 

This section explains how NHTSA has monetized and modeled air pollutant emissions of criteria 

pollutants and CO2 in developing the proposed standards using the EPCA factors. However, this 

section does not contain NHTSA’s assessment of the potential environmental impacts of the 

proposed standards and reasonable alternatives for purposes of the National Environmental 

Policy Act (NEPA), 42 U.S.C. 4321-4347. On March 28, 2008, NHTSA published a notice of 

intent to prepare an environmental impact statement (EIS) and opened the NEPA scoping 

process (73 FR 16615). NHTSA will consider the potential environmental impacts of the 

proposed standards and reasonable alternatives, including impacts associated with CO2 emissions 

and climate change, through the NEPA process. NHTSA’s NEPA analysis will inform any 

further action on the proposed standards, consistent with NEPA and EPCA. 

While reductions in domestic fuel refining and distribution that result from lower fuel 

consumption will reduce U.S. emissions of criteria pollutants, additional vehicle use associated 

with the rebound effect from higher fuel economy will increase emissions of these pollutants. 
V-92 

Thus the net effect of stricter CAFE standards on emissions of each criteria pollutant depends on 

the relative magnitudes of its reduced emissions in fuel refining and distribution, and increases in 

its emissions from vehicle use. Because the relationship between emission rates (emissions per 

gallon refined of fuel or mile driven) in fuel refining and vehicle use is different for each criteria 

pollutant, the net effect of fuel savings from the proposed standards on total emissions of each 

pollutant is likely to differ. Criteria air pollutants emitted by vehicles and during fuel production 

include carbon monoxide (CO), hydrocarbon compounds (usually referred to as “volatile organic 

compounds,” or VOC), nitrogen oxides (NOx), fine particulate matter (PM2.5), and sulfur oxides 

(SOx). 

The increase in emissions of these pollutants from additional vehicle use due to the rebound 

effect is estimated by multiplying the increase in total miles driven by vehicles of each model 

year and age by age-specific emission rates per vehicle-mile for each pollutant. NHTSA 

developed these emission rates using EPA’s MOBILE6.2 motor vehicle emissions factor 

model.101 Emissions of these pollutants also occur during crude oil extraction and transportation, 

fuel refining, and fuel storage and distribution. The reduction in total emissions from each of 

these sources thus depends on the extent to which fuel savings result in lower imports of refined 

fuel, or in reduced domestic fuel refining. To a lesser extent, they also depend on whether any 

reduction in domestic gasoline refining is translated into reduced imports of crude oil or reduced 

domestic extraction of petroleum. 

Based on analysis of changes in U.S. gasoline imports and domestic gasoline consumption 

forecast in AEO’s 2008 Early Release, NHTSA tentatively estimates that 50 percent of fuel 

savings resulting from higher CAFE standards will result in reduced imports of refined gasoline, 

while the remaining 50 percent will reduce domestic fuel refining.102 The reduction in domestic 

refining is assumed to leave its sources of crude petroleum unchanged from the mix of 90 

percent imports and 10 percent domestic production projected by AEO. 

NHTSA proposes to estimate reductions in criteria pollutant emissions from gasoline refining 

and distribution using emission rates obtained from Argonne National Laboratories’ Greenhouse 

Gases and Regulated Emissions in Transportation (GREET) model.103 The GREET model 

provides separate estimates of air pollutant emissions that occur in four phases of fuel production 

and distribution: crude oil extraction, crude oil transportation and storage, fuel refining, and fuel 

distribution and storage.104 We tentatively assume that reductions in imports of refined fuel 

 

101 U.S. Environmental Protection Agency, MOBILE6 Vehicle Emission Modeling Software, available at 

http://www.epa.gov/otaq/m6.htm#m60 (last accessed Sept. 10, 2007). 102 Estimates of the response of gasoline imports and domestic refining to fuel savings from stricter standards are 

variable and highly uncertain, but our preliminary analysis indicates that under any reasonable assumption about 

these responses, the magnitude of the net change in criteria pollutant emissions (accounting for both the rebound 

effect and changes in refining emissions) is extremely low relative to their current total. 

103 Argonne National Laboratories, The Greenhouse Gas and Regulated Emissions from Transportation (GREET) 

Model, Version 1.8, June 2007, available at http://www.transportation.anl.gov/software/GREET/index.html (last 

accessed Sept. 10, 2007). 

104 Emissions that occur during vehicle refueling at retail gasoline stations (primarily evaporative emissions of 

volatile organic compounds, or VOCs) are already accounted for in the “tailpipe” emission factors used to estimate 

the emissions generated by increased light truck use. GREET estimates emissions in each phase of gasoline 

production and distribution in mass per unit of gasoline energy content; these factors are then converted to mass per 

gallon of gasoline using the average energy content of gasoline. 
V-93 

would reduce criteria pollutant emissions during fuel storage and distribution only. Reductions 

in domestic fuel refining using imported crude oil as a feedstock are tentatively assumed to 

reduce emissions during crude oil transportation and storage, as well as during gasoline refining, 

distribution, and storage, because less of each of these activities would be occurring. Similarly, 

reduced domestic fuel refining using domestically-produced crude oil is tentatively assumed to 

reduce emissions during all phases of gasoline production and distribution.105

The net changes in emissions of each criteria pollutant are calculated by adding the increases in 

their emissions that result from increased vehicle use and the reductions that result from lower 

domestic fuel refining and distribution. The net change in emissions of each criteria pollutant is 

converted to an economic value using estimates of the economic costs per ton emitted (which 

result primarily from damages to human health) developed by EPA and submitted to the federal 

Office of Management and Budget for review. For certain criteria pollutants, EPA estimates 

different per-ton costs for emissions from vehicle use than for emissions of the same pollutant 

during fuel production, reflecting differences in their typical geographic distributions, 

contributions to ambient pollution levels, and resulting population exposure. 

(ii) Reductions in CO2 emissions 

Fuel savings from stricter CAFE standards also result in lower emissions of carbon dioxide 

(CO2), the main greenhouse gas emitted as a result of refining, distribution, and use of 

transportation fuels.106 Lower fuel consumption reduces carbon dioxide emissions directly, 

because the primary source of transportation-related CO2 emissions is fuel combustion in internal 

combustion engines. NHTSA tentatively estimates reductions in carbon dioxide emissions 

resulting from fuel savings by assuming that the entire carbon content of gasoline, diesel, and 

other fuels is converted to carbon dioxide during the combustion process.107

Reduced fuel consumption also reduces carbon dioxide emissions that result from the use of 

carbon-based energy sources during fuel production and distribution.108 NHTSA currently 

 

105 In effect, this assumes that the distances crude oil travels to U.S. refineries are approximately the same regardless 

of whether it travels from domestic oilfields or import terminals, and that the distances that gasoline travels from 

refineries to retail stations are approximately the same as those from import terminals to gasoline stations. 

106 Carbon dioxide emissions account for more than 97 percent of total greenhouse gas emissions from the refining 

and use of transportation fuels; see U.S. Environmental Protection Agency, Draft Inventory of GHG Emissions and 

Sinks (1990-1999), Tables ES-1 and ES-4. Available at

http://www.epa.gov/globalwarming/publications/emissions/us2001/energy.pdf (last accessed Sept. 10, 2007). 107 This assumption results in a slight overestimate of carbon dioxide emissions, since a small fraction of the carbon 

content of gasoline is emitted in the forms of carbon monoxide and unburned hydrocarbons. However, the 

magnitude of this overestimate is likely to be extremely small. This approach is consistent with the recommendation 

of the Intergovernmental Panel on Climate Change for “Tier 1” national greenhouse gas emissions inventories. Cf.

Intergovernmental Panel on Climate Change, 2006 Guidelines for National Greenhouse Gas Inventories, Volume 2, 

Energy, p. 3.16. 

108 We note that NHTSA did not, for purposes of this proposed rulemaking, attempt to estimate changes in emissions 

of greenhouse gases (GHGs) other than carbon dioxide. This was because carbon dioxide itself accounts for more 

than 95 percent of the total CO2-equivalent emissions of fuel production and use, even with other GHGs that result 

from those activities (principally methane and nitrous oxide) weighted by their higher global warming potentials 

(GWPs) relative to CO2. Calculated from U.S. EPA, Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-

2005, EPA430-R-07-02, April 15, 2007. Available at

http://www.epa.gov/climatechange/emissions/downloads06/07CR.pdf, Table ES-2. 
V-94 

estimates the reductions in CO2 emissions during each phase of fuel production and distribution 

using carbon dioxide emission rates obtained from the GREET model, using the previous 

assumptions about how fuel savings are reflected in reductions in each phase. The total 

reduction in CO2 emissions from the improvement in fuel economy under each alternative CAFE 

standard is the sum of the reductions in emissions from reduced fuel use and from lower fuel 

production and distribution. 

iii) Economic value of reductions in CO2 emissions 

NHTSA has taken the economic benefits of reducing CO2 emission into account in this 

rulemaking, both in developing proposed CAFE standards and in assessing the economic 

benefits of each alternative that was considered. As noted above, the 9th Circuit found in CBD

that NHTSA had been arbitrary and capricious in deciding not to monetize the benefit of 

reducing CO2 emissions, saying that the agency had not substantiated the conclusion in its April 

2006 final rule that the appropriate course was not to monetize (i.e., quantify the value of) carbon 

emissions reduction at all. 

To this end, NHTSA reviewed published estimates of the “social cost of carbon emissions” 

(SCC). The SCC refers to the marginal cost of additional damages caused by the increase in 

expected climate impacts resulting from the emission of each additional metric ton of carbon, 

which is emitted in the form of CO2.

109 It is typically estimated as the net present value of the 

impact over some time period (100 years or longer) of one additional ton of carbon emitted into 

the atmosphere. Because accumulated concentrations of greenhouse gases in the atmosphere and 

the projected impacts on global climate are increasing over time, the economic damages resulting 

from each additional ton of CO2 emissions in future years are believed to be greater as a result. 

Thus estimates of the SCC are typically reported for a specific year, and these estimates are 

generally larger for emissions in more distant future years. 

There is substantial variation among different authors’ estimates of the SCC, much of which can 

be traced to differences in their underlying assumptions about several variables. These include 

the sensitivity of global temperatures and other climate attributes to increasing atmospheric 

concentrations of greenhouse gases, discount rates applied to future economic damages from 

climate change, whether damages sustained by developing regions of the globe should be 

weighted more heavily than damages to developed nations, how long climate changes persist 

once they occur, and the economic valuation of specific climate impacts.110 

Taken as a whole, recent estimates of the SCC may underestimate the true damage costs of 

carbon emissions because they often exclude damages caused by extreme weather events or 

 

109 Carbon itself accounts for 12/44, or about 27%, of the mass of carbon dioxide (12/44 is the ratio of the molecular 

weight of carbon to that of carbon dioxide). Thus each ton of carbon emitted is associated with 44/12, or 3.67, tons 

of carbon dioxide emissions. Estimates of the SCC are typically reported in dollars per ton of carbon, and must be 

divided by 3.67 to determine their equivalent value per ton of carbon dioxide emissions. 

110 For a discussion of these factors, see Yohe, G.W., R.D. Lasco, Q.K. Ahmad, N.W. Arnell, S.J. Cohen, C. Hope, 

A.C. Janetos and R.T. Perez, 2007: Perspectives on climate change and sustainability. Climate Change 2007: 

Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. 

Hanson, Eds., Cambridge University Press, Cambridge, UK, pp. 821-824. 
V-95 

climate response scenarios with low probabilities but potentially extreme impacts, and may 

underestimate the climate impacts and damages that could result from multiple stresses on the 

global climatic system. At the same time, however, many studies fail to consider potentially 

beneficial impacts of climate change, and do not adequately account for how future development 

patterns and adaptations could reduce potential impacts from climate change or the economic 

damages they cause. 

Given the uncertainty surrounding estimates of the SCC, the use of any single study may not be 

advisable since its estimate of the SCC will depend on many assumptions made by its authors. 

The Working Group II’s contribution to the Fourth Assessment Report of the United Nations 

Intergovernmental Panel on Climate Change (IPCC)111 notes that: 

The large ranges of SCC are due in the large part to differences in assumptions 

regarding climate sensitivity, response lags, the treatment of risk and equity, 

economic and non-economic impacts, the inclusion of potentially catastrophic 

losses, and discount rates. 

 Although the IPCC does not recommend a single estimate of the SCC, it does cite the Tol 

(2005) study on four separate occasions (pages 17, 65, 813, 822) as the only available survey of 

the peer-reviewed literature that has itself been subjected to peer review. Tol developed a 

probability function using the SCC estimates of the peer reviewed literature and found estimates 

ranging from less than zero to over $200 per metric ton of carbon. In an effort to resolve some 

of the uncertainty in reported estimates of climate damage costs from carbon emissions, Tol 

(2005) reviewed and summarized one hundred and three estimates of the SCC from 28 published 

studies. He concluded that when only peer-reviewed studies published in recognized journals 

are considered, “...climate change impacts may be very uncertain but is unlikely that the 

marginal damage costs of carbon dioxide emissions exceed $50 per [metric] ton carbon [about 

$14 per metric ton of CO2].” 112 He also concluded that the costs may be less than $14. 

Because of the number of assumptions required by each study, the wide range of uncertainty 

surrounding these assumptions, and their critical influence on the resulting estimates of climate 

damage costs, some studies have undoubtedly produced estimates of the SCC that are 

unrealistically high, while others are likely to have estimated values that are improbably low. 

Using a value for the SCC that reflects the central tendency of estimates drawn from many 

studies reduces the chances of relying on a single estimate that subsequently proves to be biased. 

It is important to note that estimates of the SCC almost invariably include the value of worldwide 

damages from potential climate impacts caused by carbon dioxide emissions, and are not 

confined to damages likely to be suffered within the U.S. In contrast, the other estimates of costs 

and benefits of increasing fuel economy included in this proposal include only the economic 

values of impacts that occur within the U.S. For example, the economic value of reducing 

criteria air pollutant emissions from overseas oil refineries is not counted as a benefit resulting 

 

111 Climate Change 2007 – Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth 

Assessment Report of the IPCC, 17. Available at http://www.ipcc-wg2.org (last accessed <Feb. 4, 2008>). 112 Tol, Richard. The marginal damage costs of carbon dioxide emissions: an assessment of the uncertainties. 

Energy Policy 33 (2005) 2064–2074, 2072. The summary SCC estimates reported by Tol are assumed to be 

denominated in U.S. dollars of the year of publication, 2005. 
V-96 

from this rule, because any reduction in damages to health and property caused by overseas 

emissions are unlikely to be experienced within the U.S. 

In contrast, the reduced value of transfer payments from U.S. oil purchasers to foreign oil 

suppliers that results when lower U.S. oil demand reduces the world price of petroleum (the 

reduced “monopsony effect”) is counted as a benefit of reducing fuel use.113 If the agency’s 

analysis was conducted from a worldwide rather than a U.S. perspective, however, the benefit 

from reducing air pollution overseas would be included, while reduced payments from U.S. oil 

consumers to foreign suppliers would not. 

In order to be consistent with NHTSA’s use of exclusively domestic costs and benefits in prior 

CAFE rulemakings, the appropriate value to be placed on changes climate damages caused by 

carbon emissions should be one that reflects the change in damages to the United States alone. 

Accordingly, NHTSA notes that the value for the benefits of reducing CO2 emissions might be 

restricted to the fraction of those benefits that are likely to be experienced within the United 

States. 

Although no estimates of benefits to the U.S. itself that are likely to result from reducing CO2

emissions are currently available, NHTSA expects that if such values were developed, the 

agency would employ those rather than global benefit estimates in its analysis. NHTSA also 

anticipates that if such values were developed, they would be lower than comparable global 

values, since the U.S. is likely to sustain only a fraction of total global damages resulting from 

climate change. 

 

In the meantime, the agency has elected to use the IPCC estimate of $43 per metric ton of carbon 

as an upper bound on the benefits resulting from reducing each metric ton of U.S. emissions. 114 

This corresponds to approximately $12 per metric ton of CO2 when expressed in 2006 dollars. 

This estimate is based on the 2005 Tol study.115 The Tol study is cited repeatedly as an 

authoritative survey in various IPCC reports, which are widely accepted as representing the 

general consensus in the scientific community on climate change science. Since the IPCC 

estimate includes the worldwide costs of potential damages from carbon dioxide emissions, 

NHTSA has elected to employ it as an upper bound on the estimated value of the reduction in 

U.S. domestic damage costs that is likely to result from lower CO2 emissions.116 

 

113 The reduction in payments from U.S. oil purchasers to domestic petroleum producers is not included as a benefit, 

since it represents a transfer that occurs entirely within the U.S. economy. 114 The estimate of $43 per ton of carbon emissions is reported by Tol (p. 2070) as the mean of the “best” estimates 

reported in peer-reviewed studies (see fn. 4). It thus differs from the mean of all estimates reported in the peerreviewed studies surveyed by Tol. The $43 per ton value is also attributed to Tol by IPCC Working Group II 

(2007), p. 822. 

115 Tol’s more recent (2007) and inclusive survey has been published online with peer-review comments. The 

agency has elected not to rely on the estimates it reports, but will consider doing so in its analysis of the final rule if 

the survey has been published, and will also consider any other newly-published evidence. 

116 For purposes of comparison, we note that in the rulemaking to establish CAFE standards for MY 2008-11 light 

trucks, NRDC recommended a value of $10 to $25 per ton of CO2 emissions reduced by fuel savings and both 

Environmental Defense and Union of Concerned Scientists recommended a value of $50 per ton of carbon 

(equivalent to about $14 per ton of CO2 emissions). 
V-97 

The IPCC Working Group II Fourth Assessment Report (2007, p. 822) further suggests that the 

SCC of carbon is growing at an annual 2.4 percent growth rate, based on estimated increases in 

damages from future emissions reported in published studies. NHTSA has also elected to apply 

this growth rate to Tol’s original 2005 estimate. Thus by 2011, the agency estimates that the 

upper bound on the benefits of reducing CO2 emissions will have reached about $14 per metric 

ton of CO2, and will continue increase by 2.4 percent annually thereafter. 

In setting a lower bound, the agency agrees with the IPCC Working Group II (2007) report that 

“significant warming across the globe and the locations of significant observed changes in many 

systems consistent with warming is very unlikely to be due solely to natural variability of 

temperatures or natural variability of the systems” (pp. 9). Although this finding suggests that 

the global value of economic benefits from reducing carbon dioxide emissions is unlikely to be 

zero, it does not necessarily rule out low or zero values for the benefit to the U.S. itself from 

reducing emissions. 

For most of the analysis it performed to develop this proposal, NHTSA required a single estimate 

for the value of reducing CO2 emissions. The agency thus elected to use the midpoint of the 

range from $0 to $14 (or $7.00) per metric ton of CO2 as the initial value for the year 2011, and 

assumed that this value would grow at 2.4 percent annually thereafter. This estimate is 

employed for the analyses conducted using the Volpe CAFE model to support development of 

the proposed standards. The agency also conducted sensitivity analyses of the benefits from 

reducing CO2 emissions using both the upper ($14 per metric ton) and lower ($0 per metric ton) 

bounds of this range. 

NHTSA seeks comment on its tentative conclusions for the value of the SCC, the use of a 

domestic versus global value for the economic benefit of reducing CO2 emissions, the rate at 

which the value of the SCC grows over time, the desirability of and procedures for incorporating 

benefits from reducing emissions of greenhouse gases other than CO2, and any other aspects of 

developing a reliable SCC value for purposes of establishing CAFE standards. 

m. The value of increased driving range 

Improving vehicles’ fuel economy may also increase their driving range before they require 

refueling. By reducing the frequency with which drivers typically refuel their vehicles, and by 

extending the upper limit of the range they can travel before requiring refueling, improving fuel 

economy thus provides some additional benefits to their owners. (Alternatively, if manufacturers 

respond to improved fuel economy by reducing the size of fuel tanks to maintain a constant 

driving range, the resulting cost saving will presumably be reflected in lower vehicle sales 

prices.) 

No direct estimates of the value of extended vehicle range are readily available, so NHTSA’s 

analysis calculates the reduction in the annual number of required refueling cycles that results 

from improved fuel economy, and applies DOT-recommended values of travel time savings to 

convert the resulting time savings to their economic value.117 As an illustration of how the value 

 

117 See Department of Transportation, Guidance Memorandum, “The Value of Saving Travel Time: Departmental 

Guidance for Conducting Economic Evaluations,” Apr. 9, 1997. Available at
V-98 

of extended refueling range is estimated, a typical small light truck model has an average fuel 

tank size of approximately 20 gallons. Assuming that drivers typically refuel when their tanks 

are 20 percent full (i.e., 4 gallons in reserve), increasing this model’s actual on-road fuel 

economy from 24 to 25 mpg would extend its driving range from 384 miles (= 16 gallons x 24 

mpg) to 400 miles (= 16 gallons x 25 mpg). Assuming that it is driven 12,000 miles/year, this 

reduces the number of times it needs to be refueled each year from 31.3 (= 12,000 miles per year 

/ 384 miles per refueling) to 30.0 (= 12,000 miles per year / 400 miles per refueling), or by 1.3 

refuelings per year. 

Weighted by the nationwide mix of urban (about 2/3) and rural (about 1/3) driving and average 

vehicle occupancy for all driving trips (1.6 persons), the DOT-recommended value of travel time 

per vehicle-hour is $24.00 (in 2006 dollars).118 Assuming that locating a station and filling up 

requires ten minutes, the annual value of time saved as a result of less frequent refueling amounts 

to $5.20 (calculated as 10/60 x 1.3 x $24.00). This calculation is repeated for each future 

calendar year that vehicles of each model year affected by the alternative CAFE standards 

proposed in this rule would remain in service. Like fuel savings and other benefits, however, the 

value of this benefit declines over a model year’s lifetime, because a smaller number of vehicles 

originally produced during that model year remain in service each year, and those remaining in 

service are driven fewer miles. 

n. Discounting future benefits and costs

Discounting future fuel savings and other benefits is intended to account for the reduction in 

their value to society when they are deferred until some future date rather than received 

immediately. The discount rate expresses the percent decline in the value of these benefits – as 

viewed from today’s perspective – for each year they are deferred into the future. NHTSA uses a 

rate of 7 percent per year to discount the value of future fuel savings and other benefits to 

analyze the potential impacts of alternative CAFE standards. However, the agency also performs 

an alternative analysis of benefits from alternative increases in CAFE standards using a 3 percent 

discount rate, and seeks comment on whether the standards should be set using a 3 percent rate 

instead of a 7 percent rate. 

There are several reasons that NHTSA relies primarily on 7 percent as the appropriate rate for 

discounting future benefits from increased CAFE standards. First, OMB Circular A-4 indicates 

that this rate reflects the economy-wide opportunity cost of capital.119 It also states that this “is 

the appropriate discount rate whenever the main effect of a regulation is to displace or alter the 

use of capital in the private sector.”120 We believe that a substantial portion of the cost of this 

 http://ostpxweb.dot.gov/policy/Data/VOT97guid.pdf (last accessed October 20, 2007); update available at

http://ostpxweb.dot.gov/policy/Data/VOTrevision1_2-11-03.pdf (last accessed October 20, 2007). 118 The hourly wage rate during 2006 is estimated to be $24.00. Personal travel (94.4 percent of urban travel) is 

valued at 50 percent of the hourly wage rate. Business travel (5.6 percent or urban travel) is valued at 100 percent of 

the hourly wage rate. For intercity travel, personal travel (87 percent) is valued at 70 percent of the wage rate, while 

business travel (13 percent) is valued at 100 percent of the wage rate. The resulting values of travel time are $12.67 

for urban travel and $17.66 for intercity travel, and must be multiplied by vehicle occupancy (1.6) to obtain the 

estimate value of time per vehicle hour. 

119 Office of Management and Budget, Circular A-4, “Regulatory Analysis,” September 17, 2003, 33. Available at

http://www.whitehouse.gov/omb/circulars/a004/a-4.pdf (last accessed Feb. 14, 2008). 120 Id. 
V-99 

regulation may come at the expense of other investments the auto manufacturers might otherwise 

make. Several large manufacturers are resource-constrained with respect to their engineering 

and product-development capabilities. As a result, other uses of these resources will be foregone 

while they are required to be applied to technologies that improve fuel economy. 

Second, 7 percent also appears to be an appropriate rate to the extent that the costs of the 

regulation come at the expense of consumption as opposed to investment. NHTSA believes that 

financing rates on vehicle loans represent an appropriate discount rate, because they reflect the 

opportunity costs faced by consumers when buying vehicles with greater fuel economy and a 

higher purchase price. Most new and used vehicle purchases are financed, and because most of 

the benefits from higher fuel economy standards accrue to vehicle purchasers in the form of fuel 

savings, the appropriate discount rate is the interest rate buyers pay on loans to finance their 

vehicle purchases.121 

According to the Federal Reserve, the interest rate on new car loans made through commercial 

banks has closely tracked the rate on 10-year treasury notes, but exceeded it by about 3 

percent.122 The official Administration forecast is that real (or inflation-adjusted) interest rates 

on 10-year treasury notes will average about 3 percent through 2016, implying that 6 percent is a 

reasonable forecast for the real interest rate on new car loans.123 In turn, the interest rate on used 

car loans made through automobile financing companies has closely tracked the rate on new car 

loans made through commercial banks, but exceeded it by about 3 percent.124 (We consider rates 

on loans that finance used car purchases, because some of the fuel savings resulting from 

improved fuel economy accrue to used car buyers.) Given the 6 percent estimate for new car 

loans, a reasonable forecast for used car loans is thus 9 percent. 

Because the benefits of fuel economy accrue to both new and used car owners, a discount rate 

between 6 percent and 9 percent is thus appropriate for evaluating future benefits resulting from 

more stringent fuel economy standards. Assuming that new car buyers discount fuel savings at 6 

percent for 5 years (the average duration of a new car loan) 125 and that used car buyers discount 

fuel savings at 9 percent for 5 years (the average duration of a used car loan),126 the single 

constant discount rate that yields equivalent present value fuel savings is very close to 7 percent. 

 

121 Some empirical evidence also demonstrates that used car purchasers are willing to pay higher prices for greater 

fuel economy; see, e.g., James A. Kahn, “Gasoline Price Expectations and the Used Automobile Market: A Rational 

Expectations Asset Price Approach,” Quarterly Journal of Economics, Vol. 101 (May 1986), 323-339. 122 See Federal Reserve Bank, Statistical Release H.15, Selected Interest Rates (Weekly) (click on “Historical Data,” 

then “Treasury constant maturities,” then “10-year, monthly”), available at

http://www.federalreserve.gov/Releases/H15/data/Monthly/H15_TCMNOM_Y10.txt (last accessed February 13, 

2008); and Federal Reserve Bank, Statistical Release G.19, Consumer Credit, (click on “Historical Data,” then 

“Terms of Credit”) available at http://www.federalreserve.gov/releases/g19/hist/cc_hist_tc.html (last accessed 

February 13, 2008). 

123 See The White House, Joint Press Release of the Council of Economic Advisors, the Department of the Treasury, 

and the Office of Management and Budget, November 29, 2007, available at

http://www.whitehouse.gov/news/releases/2007/11/20071129-4.html (last accessed February 13, 2008). 124 See supra [2 above here] and Federal Reserve Bank, Statistical Release G.20, Finance Companies, (click on 

“Historical Data,” then “Terms of Credit”) available at

http://www.federalreserve.gov/releases/g20/hist/fc_hist_tc.html (last accessed February 13, 2008). 125 Id. 126 Id. 
V-100 

However, NHTSA also seeks comment on whether a discount rate of 3 percent would be more 

appropriate for this proposed rulemaking. OMB Circular A-4 also states that when regulation 

primarily and directly affects private consumption (e.g., through higher consumer prices for 

goods and services), instead of primarily affecting the allocation of capital, a lower discount rate 

may be appropriate. The alternative discount rate that is most appropriate in this case is the 

social rate of time preference, which refers to the rate at which society discounts future 

consumption to determine its value at the present time. The rate that savers are willing to accept 

to defer consumption into the future when there is no risk that borrowers will fail to pay them 

back offers one possible measure of the social rate of time preference. As noted above, the real 

rate of return on long-term government debt, which has averaged around 3 percent over the last 

30 years, provides a reasonable estimate of this value. 

In the context of CAFE standards for motor vehicles, the appropriate discount rate depends on 

one’s view of how the costs and benefits of more stringent standards are distributed between 

vehicle manufacturers and consumers. Given that the discount rate plays a big role in the level of 

the standards under a “social optimization” context, NHTSA conducted an analysis of what the 

standards and associated costs and benefits would be if the future benefits are discounted at 3 

percent. 

o. Accounting for uncertainty in benefits and costs 

In analyzing the uncertainty surrounding its estimates of benefits and costs from alternative 

CAFE standards, NHTSA has considered alternative estimates of those assumptions and 

parameters likely to have the largest effect. These include the projected costs of fuel economyimproving technologies and their expected effectiveness in reducing vehicle fuel consumption, 

forecasts of future fuel prices, the magnitude of the rebound effect, the reduction in external 

economic costs resulting from lower U.S. oil imports, the value to the U.S. economy of reducing 

carbon dioxide emissions, and the discount rate applied to future benefits and costs. The range 

for each of these variables employed in the uncertainty analysis is presented in the section of this 

notice discussing each variable. 

The uncertainty analysis was conducted by assuming independent normal probability 

distributions for each of these variables, using the low and high estimates for each variable as the 

values below which 5 percent and 95 percent of observed values are believed to fall. Each trial 

of the uncertainty analysis employed a set of values randomly drawn from each of these 

probability distributions, assuming that the value of each variable is independent of the others. 

Benefits and costs of each alternative standard were estimated using each combination of 

variables. A total of 1,000 trials were used to establish the likely probability distributions of 

estimated benefits and costs for each alternative standard. 

C. How has NHTSA used the Volpe model to select the proposed standards? 

1. Establishing a continuous function standard
V-101 

NHTSA’s analysis supporting determination of the proposed continuous function standard builds 

on the analysis that supported the determination of the standards in NHTSA’s 2006 light truck 

final rule. That process involved three steps.127

In “phase one,” NHTSA added fuel saving technologies to each manufacturer’s fleet, model by 

model, for a model year until the net benefit from doing so reached its maximum value (i.e., until 

the incremental cost of improving its fuel economy further just equals the incremental value of 

fuel savings and other benefits from doing so). This was done for each of the seven largest 

manufacturers. Data points representing each vehicle’s size and “optimized” fuel economy from 

the light truck fleets of those manufacturers were then combined into a single data set. 

In “phase two,” a preliminary continuous function was statistically fitted through these data 

points, subject to constraints at the upper and lower ends of the footprint range. 

Once a preliminary continuous function was statistically fitted to the data for a model year, 

“phase three” was performed. In that phase, the level of the function was adjusted to maximize 

net benefits, that is, the preliminary continuous function was raised or lowered until industrywide (limited to the seven largest manufacturers) benefits were maximized. 

For NHTSA’s 2006 light truck rulemaking, the optimization procedure was applied in its entirety 

only for MY 2011. The levels of the functions for MYs 2008-2010 were set at levels producing 

incremental costs approximately equivalent to those produced by the alternative Unreformed 

CAFE standards promulgated for those model years in the same rulemaking. 

Analysis conducted by NHTSA to prepare for the current proposed rulemaking revealed several 

opportunities to refine the procedure described above before applying it to this action, which 

spans several model years. The resultant procedure is described below. 

2. Calibration of initial continuous function standards

For the optimized standards, the first step in the current procedure involves all three phases 

described above. Separately, for each of the seven largest manufacturers, the agency determined 

the level of additional technology that would maximize net benefits. The agency then combined 

the resultant fleets and used standard statistical analysis procedures to specify a continuous 

function (i.e., a function without abrupt changes) with asymptotes128 set at the average fuel 

economy levels of the smallest and largest vehicles in this “optimized” fleet.129

 

127 See 71 FR 17596-97 (Apr. 6, 2006) for a more complete discussion of this process. 128 Some functions are not bounded. For example, a line that is not flat will increase in one direction without limit 

and will, in the other direction, decrease without limit. The continuous function applied by the agency is of a form 

with upper and lower boundaries. Even as vehicle footprint declines or increases, the function’s value (in mpg or 

grams/mile) will never exceed or fall below a specific value. These upper and lower limits are called asymptotes. 

129 Consistent with EPCA, the passenger car and light truck fleets were analyzed separately. For passenger cars, the 

agency determined the asymptotes of the continuous function by calculating the average fuel economy of the 

smallest 8 percent and the largest 5 percent of the fleet. For light trucks, the agency considered the smallest 11 

percent and the largest 10 percent of the fleet. These cohorts were determined by identifying gaps in the distribution 

of vehicles according to footprint. 
V-102 

In the 2006 Light Truck Rule, NHTSA created an attribute-based fuel economy standard based 

upon a continuous function using a logistic curve. The 2006 rulemaking, and its antecedent 

advanced notice of proposed rulemaking, contains an extended discussion of alternative 

approaches, including a bin-based system and different potential curves.130 As discussed below, 

the rulemaking explains NHTSA’s decision to promulgate a standard based on a logistic (“S 

shaped”) curve with constrained asymptotes (upper and lower limits). 

Although we did not explicitly recognize it in the MY 2008-2011 light truck rulemaking, 

NHTSA now wishes to note that any continuous function with upper and lower asymptotes, as 

was promulgated in the last rulemaking and is proposed in this rulemaking, in fact has an 

absolute lower limit specified by the lower asymptote, which guards against the risk of upsizing 

to a great degree. As vehicle footprint continues to increase, decreases in the corresponding 

target become progressively smaller, such that the target approaches but never reaches the value 

of the lower asymptote. Because the required level of CAFE is the harmonic average of targets 

applicable to a manufacturer’s vehicle models, the value of the standard can approach but will 

never fall to the value of this lower asymptote, no matter how far the manufacturer’s product mix 

shifts toward larger vehicles. This will prevent loss of fuel savings due to manufacturer 

decisions to upsize their vehicles. 

NHTSA has adopted the same approach for this proposed rulemaking. However, while the 

principles underlying the Agency’s decision in 2006 continue to be compelling, the application 

of the logistic curve approach to passenger cars has persuaded us that it may be appropriate to 

reconsider the choice of the logistic curve for setting a continuous function, at least for passenger 

cars. 

NHTSA would prefer to let vehicle data define the shape of the curve used for the continuous 

functions. However, NHTSA must also weigh certain practical public policy considerations in 

establishing the continuous function, including for regions where vehicles are not currently being 

built in significant numbers, but might become available in the future. In establishing footprintbased CAFE standards, the agency’s objective is not to reflect a clear engineering relationship 

between footprint and fuel economy. Other attributes would be more closely correlated with fuel 

economy. The agency’s objective is to make CAFE regulations more consistent with public 

policy goals, in particular (1) a rebalancing of requirements such that full-line manufacturers are 

not disproportionately burdened and (2) the establishment of an incentive that discourages 

manufacturers from responding to CAFE standards in ways that could compromise occupant 

protection and highway safety. While it is helpful that the attribute—in this case footprint—has 

an observed relationship to fuel economy, it is not necessary that this relationship be isolated 

from accompanying relationships (e.g., between weight and fuel economy) that can be better 

related to estimable physical processes. Similarly, it is more important that the functional form 

for the attribute-based standard yield desirable outcomes than that it have a clear foundation in 

estimable physical processes. 

In general, public policy considerations and available vehicle data combine to suggest that the 

fuel economy standard should be generally downward sloping (on a fuel economy basis) with 

respect to NHTSA’s chosen attribute, vehicle footprint. The arguments that favor an attribute-

 

130 FR 
V-103 

based system (maintaining consumer choice, protecting safety, more equitable distribution of 

costs, reducing the cost of regulation) all argue for a downward sloping curve. Larger vehicles 

should, in principle, have higher drag, weigh more, and therefore have greater inertia than 

otherwise identical smaller vehicles. Hence, all other factors remaining equal, larger vehicles 

should have lower fuel economy than smaller vehicles. Therefore, the selection of vehicle 

footprint as the reference attribute should produce downward sloping curves. Also, the tendency 

of larger vehicles to have lower fuel economy than smaller vehicles should provide some 

disincentive to shift to larger vehicles rather than adding technology; although doing so would 

tend to reduce the required CAFE level, it would also tend to reduce the achieved CAFE level. 

However, vehicle data, by itself, does not necessarily define what functional form that the curve 

ought to take. In the 2006 light truck rulemaking, NHTSA considered a linear, quadratic, 

exponential, unconstrained logistic, and constrained logistic functions as possible alternatives. 

For light trucks, the various approaches produced broadly similar standards through the most 

commonly used vehicle sizes, but drastically different standards at the high and low ends of the 

range. 

• Linear functions produced very high fuel economy standards for the smallest 

vehicles, and low standards for the largest vehicles. 

• The quadratic function generated a minimum at about 75 square feet, and then 

perversely turned upward for vehicles with larger footprints. The standard for very 

small vehicles was unreasonably high. 

• The exponential and unconstrained logistic functions produced unreasonably high 

standards for small vehicles, but flattened out for larger vehicles. 

• The constrained logistic function provided a broadly linear downward-sloping 

through the most commonly used vehicle sizes, along with basically flat standards for 

very large and very small vehicles. 

On this basis, NHTSA believed that, while the data did not dictate a particular functional form, 

public policy considerations made the constrained logistic function particularly attractive. The 

considerations include: 

• A relatively flat standard for larger vehicles acts as a de facto ‘backstop’ for the 

standard in the event that future market conditions encourage manufacturers to build 

very large vehicles. Nothing prevents manufacturers from building larger vehicles. 

With a logistic curve, however, vehicles upsizing beyond some limit face a flat 

standard that is increasingly difficult to meet. 

• A constrained logistic curve doesn’t impose unachievable fuel economy standards on 

vehicles that have unusually small footprints, thus continuing to keep manufacturing 

fuel-efficient small vehicles available as a compliance option. 
V-104 

• Infeasible sections of the curve can have may be unimportant for the industry at large 

while having a particular adverse impact on manufacturers that specialize in very 

large or small vehicles, for example, two-seater sports car. 

• The transition from the ‘flat’ portions of the curve to the ‘slope’ portions of the curve 

is smooth and gradual, reducing the incentive for manufacturers to achieve 

compliance through marginal changes in vehicle size. 

• The inflection points are set by the data and can potentially vary from year to year, 

rather than being chosen by NHTSA. 

On the other hand, a constrained logistic curve shares with other functional forms a risk of an 

excessively steep or excessively flat slope. The slope of the compliance curve may be 

considered as ‘too steep’ for public policy purposes when manufacturers can achieve appreciable 

reductions in compliance costs by marginally increasing the size of a vehicle’s footprint—e.g., 

the cost of compliance from upsizing is lower than other cost-effective compliance methods open 

to manufacturers. 

A slope is ‘too flat’ for public policy purposes when it negates the advantages of an attributebased system: where the standard doesn’t meaningfully vary with respect to changes in the 

underlying attribute, it cannot be said to be an attribute-based system within the meaning of the 

statute. 

NHTSA chose footprint as the best attribute for an attribute-based standard in part because we 

believed changing a vehicle’s footprint would involve significant costs for manufacturers, 

probably requiring a redesign of the vehicle. 

While “too steep” or “too flat” inevitably cannot be defined with precision, they need to be kept 

in mind. 

For the proposed standards, the agency defined the continuous function using the following 

formula: 

( )

( )

1

1 11

1

xc d

x c d

T

e

a ba e

−

−

=

⎛ ⎞ + − ⎜ ⎟ ⎝ ⎠ +

where 

 T = the fuel economy target (in mpg) 

a = the maximum fuel economy target (in mpg) 

b = the minimum fuel economy target (in mpg) 
V-105 

c = the footprint value (in square feet) at which the fuel economy target is midway 

between a and b131

d = the parameter (in square feet) defining the rate at which the value of targets 

decline from the largest to smallest values 

e = 2.718132

x = footprint (in square feet, rounded to the nearest tenth) of the vehicle model 

As for analysis of the light truck rule promulgated in 2006, NHTSA constrained this function by 

determining the maximum and minimum targets (a and b) and then holding those targets 

constant while using statistical techniques to fit the other two coefficients (c and d) in this 

equation. 

In the current analysis for passenger cars, the upper and lower asymptotes are based on the smallest 

three percent and largest four percent, respectively, of the fleet. These reflect footprint values defining 

distinct cohorts outside the bulk of the fleet, and correspond to footprint values of less than 39.5 square 

feet (i.e., up to the approximate size of a Honda Fit) and greater than 52.5 square feet (i.e., at least as 

great as the approximate size of a Toyota Avalon), respectively: 

Figure V-6. Passenger Automobile Footprint Distribution 

 

131 That is, the midpoint. 

132 For the purpose of the Reformed CAFE standard, we are carrying e out to only three decimal places. 

0%

5%

10%

15%

20%

25%

<35

35.5-3636.5-3737.5-3838.5-3939.5-4040.5-4141.5-4242.5-4343.5-4444.5-4545.5-4646.5-4747.5-4848.5-4949.5-5050.5-5151.5-5252.5-5353.5-5454.5-5555.5-5656.5-5757.5-5858.5-5959.5-60

Footprint (sf)

Percent of Vehicle Models

smallest 3%

Honda Fit,

[Ford B Car],

and smaller

largest 4%

Toyota 

Avalaon

and larger
V-106 

For light trucks, the upper asymptote (i.e., the highest mpg value of the continuous function defining 

fuel economy targets) is based on the smallest (in terms of footprint) eleven percent of the fleet, and 

the lower asymptote is based on the largest six percent of the fleet. These cohorts correspond to 

footprint values of less than 44.5 square feet (i.e., up to the approximate size of a Honda CR-V) and 

greater than 72.5 square feet (i.e., comprised primarily of extended vans and long-bed pickup trucks), 

respectively: 

Figure V-7. Nonpassenger Automobile Footprint Distribution 

0%

5%

10%

15%

20%

25%

42.5-4343.5-4444.5-4545.5-4646.5-4747.5-4848.5-4949.5-5050.5-5151.5-5252.5-5353.5-5454.5-5555.5-5656.5-5757.5-5858.5-5959.5-6060.5-6161.5-6262.5-6363.5-6464.5-6565.5-6666.5-6767.5-6868.5-6969.5-7070.5-7171.5-7272.5-7373.5-7474.5-7575.5-76

Footprint (sf)

Percent of Vehicle Models

smallest 11%

Honda CRV

GM Colorado/Canyon

and smaller

largest 6%

longbed 

pickups

NHTSA invites comment on the identification of vehicle cohorts for purposes of establishing 

upper and lower limits (asymptotes) bounding the attribute-based standard. After updating its 

baseline market forecast in consideration of new product plan information from manufacturers, 

the agency plans to reevaluate these cohorts for both passenger cars and light trucks before 

promulgating a final rule, and notes that changes in approach could lead to changes in 

stringency. 

Given the above asymptotes, fitting the above functional form to the “optimized” passenger car 

fleet resulted in the following initial continuous functions: 
V-107 

Figure V-8. Initial Continuous Functions (Passenger Cars), Before Optimization 

20

25

30

35

40

45

35 40 45 50 55

Footprint (sf)

Target (mpg)

2011

2012

2013

2014

2015

 

For each model year, NHTSA then raised or lowered the resultant continuous function until net 

benefits were maximized for the seven largest manufacturers (in total). Without subsequent 

recalibrations discussed below, this produced the following continuous functions for passenger 

cars:
V-108 

Figure V-9. Initial Continuous Functions (Passenger Cars), After Optimization 

20

25

30

35

40

45

35 40 45 50 55

Footprint (sf)

Target (mpg)

2011

2012

2013

2014

2015

The agency followed the same procedures for setting light truck standards and doing so resulted 

in the following continuous functions: 
V-109 

Figure V-10 

Initial Continuous Functions (Light Trucks), After Optimization 

20

25

30

35

35 40 45 50 55 60 65 70

Footprint (sf)

Target (mpg)

2011

2012

2013

2014

2015

In fitting the continuous function, NHTSA considered a range of statistical estimation 

techniques. In the 2006 light truck rulemaking, NHTSA estimated the parameters of the logistic 

function using fuel consumption (measured in gallons per mile) for each vehicle produced in a 

particular model year, weighted by sales 

For this rulemaking, we observed that estimated fuel consumption functions for passenger cars 

were significantly affected by several outliers—a small number of popular vehicles that had 

significantly higher fuel economy than the fleet as a whole and, even more so, than vehicles of 

similar footprint. For passenger cars, the function, as estimated by weighted ordinary least 

squares, was exceptionally steep within the range considered. This observation, in turn, led 

NHTSA to consider alternative approaches to statistically fitting the continuous function. 

Among the options considered by NHTSA were the following: dropping the outlying vehicles 

from the estimation process, weighted and unweighted ordinary least squares, and weighted and 

unweighted mean absolute deviation (MAD). MAD is a statistical procedure that has been 

demonstrated to produce more efficient parameter estimates in the presence of significant 

outliers.133 As examples, the following two charts show the MY2015 passenger car and light 

 

133 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 
V-110 

truck fleets after the application of technologies to each manufacturers’ fleet. These charts 

reveal numerous outliers for the passenger car fleet and, to a lesser extent, the light truck fleet: 

Figure V-11. MY2015 Passenger Car Fleet after Technology Application 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

Figure V-12. MY2015 Light Truck Fleet after Technology Application 

 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). 
V-111 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

NHTSA requests comment on the best method for statistically fitting the continuous function. 

There are strong theoretical arguments for using an unweighted (rather than weighted) analysis. 

Although the purpose of the attribute-based standard is to discourage downsizing and more 

equitably distribute compliance burdens among manufacturers, we expect the associated curve to 

be most successful if it is based on the observed physical relationship between vehicle size (i.e., 

footprint) and fuel economy. The curve reflects this relationship by depicting the variety of 

vehicle designs that have been produced in the real world for any given footprint. It is a 

measure of what is possible, not what consumers currently choose to buy. 

Consider a scenario in which there are only 2 vehicle designs with exactly the same footprint, 

both from the same manufacturer. The manufacturer sells 1,000 units of design A and 100 units 

of design B. Either design could be produced in any number (no vehicle-specific resource 

constraint). The difference in sales is due to a variety of marketing considerations including 

vehicle styling, price, performance, fuel economy, etc., that have made one vehicle model more 

popular than the other. To describe the potential fuel economy capability at any given footprint, 

we want to recognize that both vehicles represent equally valid and viable designs. If we weight 

them according to sales, we will set standards that are biased towards existing fleet profiles 

rather than reflecting design potential. 

However, the process by which we select the stringency (as distinct from the form) of the 

standard must consider sales volumes because the standards are based on sales-weighted average 

performance. Therefore, even if we use unweighted analysis develop the form of the standard, 
V-112 

we would continue to evaluate the standard’s stringency (and, therefore, its costs and benefits) 

based on sales-weighted average calculations done on a manufacturer-by-manufacturer basis. 

 

There is already precedent for using unweighted data to produce curves that are descriptive of 

engineering relationships. In NHTSA’s Preliminary Regulatory Impact Analysis for FMVSS 

216 roof crush standards, a series of force-versus-deflection curves were produced for individual 

vehicle models and then averaged together. In that case, the agency was seeking observed 

relationships that reflect engineering possibilities, rather than a profile of the existing sales fleet. 

In terms of relative emphasis on different vehicle models, the distinction between unweighted 

and weighted analysis is profound in the light vehicle market, in part because of the way 

“models” are defined for purposes of CAFE. The highest-selling passenger car model represents 

356,000 units, and the lowest-selling model represents only 5 units. As a group, the five lowestselling models represent only 305 units. Thus, weighted analysis places more than 1,000 times 

the emphasis on the highest-selling model than on the five lowest-selling models, and more than 

70,000 times the emphasis than on the single lowest-selling model. The following histograms 

shows the broader distributions of models and sales with respect to model-level sales (first for 

passenger cars, then for light trucks): 

Figure XX. Passenger Car Model Sales Volumes 

0%

5%

10%

15%

20%

25%

30%

35%

<1,000

1,001 - 2,0002,001 - 5,000

5,001 - 10,000

10,001 - 20,00020,001 - 50,000

50,001 - 100,000

100,001 - 200,000200,001 - 500,000

Annual Sales per Model

Share of Fleet (Models, Sales)

Models

Sales

Figure V-13. Light Truck Model Sales Volumes 
V-113 

0%

5%

10%

15%

20%

25%

30%

35%

<1,000

1,001 - 2,0002,001 - 5,000

5,001 - 10,000

10,001 - 20,00020,001 - 50,000

50,001 - 100,000

100,001 - 200,000200,001 - 500,000

Annual Sales per Model

Share of Fleet (Models, Sales)

Models

Sales

For purposes of setting the stringency of the corporate average fuel economy standard, this is 

vital because enforcement is based on the sales-weighted average. However, for purposes of 

developing a curve intended to represent fuel economy levels achieved at a given footprint, 

weighted analysis effectively ignores many models. 

On the other hand, unweighted estimation is depending on the definition of a “model”. 

Manufacturers will sometimes offer substantially similar vehicles with different badges (i.e., 

Ford Taurus/Mercury Sable) as two different models. The distinction between differing ‘options 

packages’ on a single model and two distinct models is inevitably a bit blurry. When estimating 

fuel economy standards using a sales-weighted regression, this distinction is not material, since 

the estimation process will produce substantially the same results independently of the number of 

distribution of those sales into larger or smaller numbers of models. In unweighted estimation, 

however, dividing a particular vehicle family into a larger number of distinct models give that 

family some extra influence in the analysis. Nonetheless, considering that such parsing into 

similar “models” produces far less weighting disparity than does sales weighting (as illustrated 

by the 70,000-to-1 ratio mentioned above), NHTSA has tentatively concluded that unweighted 

estimation remains preferable to sales-weighted estimation. 

The following charts shows, for MY2015 passenger cars and light trucks, how the use of salesweighted least-squares estimation compares to the proposed approach, which uses unweighted 

mean absolute deviation. For passenger cars, the curve resulting from proposed approach is 

somewhat shallower than the curve resulting from sales-weighted least squares estimation. For 

light trucks, the curve resulting from proposed approach is somewhat steeper: 
V-114 

Figure V-14. Weighted Least Squares Regression Compared to Proposed Curve (Using 

Unweighted Mean Absolute Deviation) for MY2015 Passenger Cars with Technologies 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Using Weighted Least Squares

Figure V-15. Weighted Least Squares Regression Compared to Proposed Curve (Using 

Unweighted Mean Absolute Deviation) for MY2015 Light Trucks with Technologies 
V-115 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

MY2105 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Based on Weighted Least Squares

NHTSA invites comment on the relative merits of unweighted and weighted estimation, as well 

as on the other curve fitting options (e.g., the use of mean absolute deviation) raised here. The 

agency plans to reevaluate curve fitting approaches for both passenger cars and light trucks 

before promulgating a final rule, and notes that changes in approach could lead to changes in 

stringency and impacts on different manufacturers.] 

3. Adjustments to address policy considerations 

NHTSA believes that the resultant curve characteristics discussed above are empirically correct 

in that they correspond to the footprint and fuel economy values of the fleet obtained by adding 

fuel saving technologies to each manufacturer’s fleet until the net benefit from doing so reached 

its maximum value. 

However, there are three issues (described above) which may tend to reduce the effectiveness of 

fuel economy regulation over time. These concerns are: 

• curve crossings; 

• excessive steepness of the passenger car curve; 

• risk of upsizing. 

In this rule, NHTSA proposes a solution to the curve crossing issue, requests comment on 

various methods of reducing the steepness of the passenger car, and examines the potential for 

upsizing generally under the provisions of this proposed rule. 

a. Curve crossings 
V-116 

For both passenger cars and light trucks, NHTSA observed some curve crossings from one 

model year to the next (i.e., for the same footprint, some targets fell below the levels attained in 

the previous model year), as revealed in the above charts. The upper limit of the MY2012 

passenger car curve falls slightly (about 0.1 mpg) below the MY2011 value. For light trucks, the 

lower asymptote in MY2012 is 0.9 mpg below the lower asymptote in MY2011. This was not 

observed during the last round of light truck rulemaking because reformed CAFE was fully 

implemented only in MY 2011. During the transition period (MYs 2008-2010), the standards 

were set at levels equivalent in cost to unreformed CAFE. However, for this rulemaking, 

because the projected fleet composition changes between model years and the fuel economy 

target function is optimized in every model year, the initial continuous functions do not change 

monotonically (i.e., in only one direction—increasing) from year to year at every footprint value. 

Given the availability of lead time and the importance of improving fuel economy, NHTSA has 

decided that, in the setting of the standards, we should ensure that the fuel economy targets do 

not fall from one year to the next at any footprint value. 

To address the year-to-year fluctuations in the functions, which may lead to these curve 

crossings, NHTSA recalibrated each continuous function to prevent it from crossing the 

continuous function from any previous model year. In doing so, the agency attempted to avoid 

continuous functions that would artificially encourage the product mix to approximate that of 

earlier years. Instead, the agency recalibrated by gradually shifting the initial continuous 

functions for each model year toward the initial continuous function determined above for the 

product mix for MY 2015. For both passenger cars and light trucks, the agency adjusted each of 

the four coefficients in the formula determining the continuous function such that regular steps 

were taken year by year between the values determined above for MY 2011 and those for MY 

2015. For example, the inflection point (the coefficient determining the footprint at which the 

target falls halfway between its minimum and maximum values) defining the light truck target 

function was increased by 0.034 square feet annually from 51.9 square feet in MY 2011 to 52.1 

square feet in MY 2015. 

NHTSA also recalibrated the continuous function for each model year by adding, as needed, 

anti-backsliding constraints that prevent the function from either (a) yielding an industry wide 

average level of CAFE lower than that for the preceding model year, (b) for a given footprint, 

having targets that fall below the level of previous year, and (c) having an asymptote lower than 

that of the preceding model year. The “decision tree” for determining for each model year the 

need for each of these constraints is summarized below in Figure 12. 

Figure V-16. Anti-backsliding Decision Tree 
V-117 

Perform 

ManufacturerLevel Optimization

Integrate 

Optimized Fleets

Fit Initial Target 

Function for Each 

Model Year

Shift Target 

Function to 

Maximize Net 

Benefits in Current 

Model Year

Compared to Previous 

Model Year, Has Either 

Asymptote Declined?

Use Initial Target 

Function from 

Previous Model 

Year

Yes

Proceed to Next 

Model Year

No

Does the Curve Cross Any 

Other Curves?

No

Yes

The industry-wide average CAFE is prevented from decreasing between model years in order to 

prevent standards from falling below the level that was determined to be achievable for the 

model year before. To allow the industry-wide CAFE level to fall between successive model 

years would be to promulgate a standard that, notwithstanding maximizing net benefits, falls 

below what the agency has determined to be feasible in previous years. In a model year in which 

simple maximization of net benefits would have caused this to occur, NHTSA shifted the 

resultant curve upward (without changing the curve’s shape) in order to produce an industrywide CAFE equal to that of the preceding model year. 
V-118 

b. Steep curves for passenger cars 

NHTSA has developed a set of attribute-based curves for passenger cars for this proposal 

consistent with the methodology used in the 2008-2011 light duty truck rule. However, unlike 

the relatively gradually sloped curve relating fuel economy to footprint for trucks, our analysis 

for cars when utilizing a constrained logistic curve produces a comparatively steep “S”-shaped 

curve for passenger cars. This occurs primarily because – unlike trucks – current passenger car 

sales include vehicles with a wide range of fuel economy spanning a relatively narrow footprint 

range. Consequently, there is a relatively steep curve applied to the middle range of footprint 

values with a more rapid change of slope in the tails to flatten the curve and thus satisfy the 

constrained logistic functional form. 

In this Rule, NHTSA is proposing a relatively “steep” curve. The agency has considered and 

experimented with several methods of reducing the steepness of the passenger car curve. 

However, each of these approaches has created challenges that may potentially be worse than the 

problem they are trying to cure. 

However, any attempt to ‘fix’ the steepness of the passenger car curve appears to come at a 

price: First, flattening the curve by any particular method will move the curve away from the 

actual vehicle data. Second, flatter curves are generally place greater compliance burdens on 

full-line manufacturers than comparatively stringent (in terms of average require CAFE) 

standards. This tends to increase the overall costs required to achieve a given amount of fuel 

savings and societal benefits, and it increases the risk that NHTSA would need to return to a 

“least capable manufacturer” approach in order to ensure economic practicability. Doing so 

would likely reduce stringency, and reduce fuel savings. In deciding on a particular approach, 

NHTSA must balance the certainty of high costs and lost fuel savings through a less “efficient” 

standard against the risk that the steepness of the curve might stimulate manufacturers to evade 

the standard over time by redesigning their vehicles over time. 

In proposing steep curve for this rule, NHTSA has tentatively decided that the cures that we have 

identified come at too high a price is lost stringency or undesirable side effects. However, 

NHTSA requests comment on these and other potential solutions to reduce the steepness of the 

proposed car curves. 

Some of the approaches considered or tested by NHTSA include: 

Linear standards. When the fuel consumption of vehicles with added technologies is plotted 

against footprint, we note a roughly linear relationship over the existing range of footprint 

values. Hence, a simple alternative to the current constrained logistic function would be to 

estimate a linear form of the curve with the sales data. However, NHTSA is concerned that such 

an approach may result in very low fuel economy standards for the largest footprint vehicles, 

very high fuel economy standards for the smallest vehicles, and loss of the inherent backstop 

properties of the constrained logistic function. 

In addition, the slope of a line estimated through a ‘cloud’ of data may be very sensitive to the 

exact characteristics of vehicles with the largest and smallest footprints. It may turn out that 
V-119 

small changes in vehicle characteristics in the tails could shift the slope of a linear estimate. 

Further, it may be impossible to materially adjust the slope of a linear standard in future years 

without accepting curve crossing. The following two charts compare linear regression results for 

MY2015 to the curves proposed today by NHTSA. The result for passenger cars illustrates the 

concern regarding behavior at large and small footprints. Over the range of footprints in which 

light trucks are expected to be offered in MY2015, the result for light trucks shows less 

difference from the proposed curve. 

Figure V-17. Linear Fit to MY2015 Passenger Cars with Technologies 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Linear Fit

Figure V-18. Linear Fit to MY2015 Light Trucks with Technologies 
V-120 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

MY2105 Fleet

Proposed Curve (Before Optimization)

Linear Fit

 

Constrained linear standards. Another possible approach would be to retain the flattened tails 

proposed today but reduce the steepness of the middle portion by allowing it to directly reflect a 

linear relationship. This approach could be likened to a simplification or linearization of the 

constrained logistic function. The same minima and maxima would be used to bound the vertical 

extent of the linear form. The following two charts suggest that, at least for the MY2015 

passenger car and light truck fleets considered today, a constrained linear standard would, 

compared to the standard proposed today, likely result in a similar distribution of compliance 

burdens among manufacturers (because the stringency at each footprint would be similar): 

Figure V-19. Constrained Linear Fit to MY2015 Passenger Cars with Technologies 
V-121 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Constrained Linear

Figure V-20. Constrained Linear Fit to MY2015 Light Trucks with Technologies 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

MY2105 Fleet

Proposed Curve (Before Optimization)

Constrained Linear
V-122 

However, the agency remains concerned that the slope could exhibit greater year-to-year 

variation than the proposed logistic form (although further analysis would be required in order to 

address this concern). Also, as discussed in the preamble to the 2006 Federal Register notice 

regarding light truck CAFE standards, the agency remains concerned that the upper and lower 

“kinks” in the function could offer unexpected incentives for manufacturers to redesign vehicles 

with footprints close to the kink-point. 

Dual Attribute Approaches. A third possible solution would be to use additional attributebased information to spread out the distribution of passenger cars across the x-axis. In effect, 

this approach uses a second attribute to normalize the footprint-fuel economy relationship. This 

second attribute might be horsepower, weight, or horsepower-to-weight. 

In analyzing the expected passenger car market, NHTSA observes that the ratio of engine 

horsepower to vehicle weight generally increases with increasing footprint. Higher power-toweight ratios tend to imply lower fuel economy, as the engine is typically larger and operating 

less efficiently under driving conditions applicable to certification. Thus, the fuel consumption 

versus footprint curves for passenger cars reflect this relationship. For trucks, there does not 

appear to be a relationship between footprint and the power-to-weight ratio. For passenger cars, 

then, adjusting fuel consumption values to normalize for differences in power-to-weight ratio 

may produce a flatter curve providing less of an upsizing incentive for middle footprint values. 

NHTSA has experimented with normalizing footprint by horsepower-to-weight ratio. The result 

was a nearly flat standard with respect to footprint across the most popular size ranges. This did 

not appear to deliver the benefits of an attribute-based system. In addition, it involves significant 

downward adjustments to the fuel economy of hybrid electric vehicles (such as the Toyota 

Prius), for which the engine is not the sole source of motive power. Also, it involves significant 

upward adjustments to the fuel economy of vehicles with high power-to-weight ratios (such as 

the Chevrolet Corvette). Some of these upward and downward adjustments are large enough to 

suggest radical changes in the nature of the original vehicles. Furthermore, insofar as such 

normalization implies that NHTSA should adopt a two-attributed standard (e.g., in which the 

target depends on footprint and power-to-weight ratio), it may be challenging and time 

consuming to come up with a sufficiently precise vehicle-by-vehicle definition of horsepower or 

horsepower-to-weight to be used for regulatory purposes. 

Figure V-21. Constrained Logistic Curve after Normalization for Differences in Power-toWeight Ratio (MY2015 Passenger Cars with Technologies) 
V-123 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic after Normalization for Power/Weight

Shape Based on Combined Fleet. A fourth possible solution would be to combine the 

passenger car and light truck fleet to determine the shape of the constrained logistic curve, and 

then determine the stringency (i.e., height) of that curve separately for each fleet. On one hand, 

this approach would base the curve’s shape on the widest available range of information. On the 

other, the resultant initial shape for each fleet would be based on vehicles from the other fleet. 

For example, the initial shape applied to passenger cars would be based, in part, on large SUVs 

and pickup trucks, and the initial shape applied to light trucks would be based, in part, on 

subcompact cars. Stringency would still be determined separately for passenger cars and light 

trucks, NHTSA invites comments on the consistency of this approach with the requirement in 

EPCA to establish separate standards for passenger cars and light trucks. 

NHTSA performed a preliminary analysis of this approach. Considering the very wide range of 

fuel consumption levels in the combined fleet, NHTSA developed the asymptotes based on the 

average fuel consumption of all passenger cars and light trucks, respectively, rather than on the 

smallest passenger cars and the largest light trucks. The resultant MY2015 curve, shown below, 

is similar in curvature to the proposed curve for passenger cars and notably steeper than the 

proposed curve for light trucks. 

Figure V-22. Constrained Logistic Curve Based on Combined Fleet (as Compared to MY2015 

Passenger Cars with Technologies) 
V-124 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Based on Combined Fleet

Figure V-23. Constrained Logistic Curve Based on Combined Fleet (as Compared to MY2015 

Light Trucks with Technologies) 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

MY2105 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Based on Combined Fleet
V-125 

Ignoring Outliers. A fifth possible solution would be to ignore outliers. Lacking an objective 

means of classifying specific vehicle models as outliers that should be excluded from the 

analysis, NHTSA explored the possibility of excluding all hybrid electric vehicles (HEVs). The 

Japanese government also excluded HEVs for purposes of developing Japan’s light vehicle 

efficiency standards. However, doing so yield initial curves of shape similar to those proposed, 

but displaced slightly in the direction of lower fuel consumption. The similarity of the shapes of 

these curves suggests that optimization against the full fleet (with HEVs) would produce 

standards of stringency similar to those proposed today. 

Figure V-24. Constrained Logistic Curve Based on MY2015 Passenger Car Fleet with 

Technologies and Excluding HEVs 

0

0.01

0.02

0.03

0.04

0.05

35 40 45 50 55 60

Footprint (sf)

Fuel Consumption (gpm)

MY2015 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Based on no-HEV Fleet

Figure V-25. Constrained Logistic Curve Based on MY2015 Passenger Car Fleet with 

Technologies and Excluding HEVs 
V-126 

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

35 40 45 50 55 60 65 70

Footprint (sf)

Fuel Consumption (gpm)

MY2105 Fleet

Proposed Curve (Before Optimization)

Constrained Logistic Based on no-HEV Fleet

NHTSA invites comments on the importance of addressing the relative steepness of the proposed 

curves for passenger cars, and on the feasibility of, technical basis for, and implications of any 

options for doing so. The agency plans to reevaluate standards for both passenger cars and light 

trucks before promulgating a final rule, and notes that changes in approach—including measures 

to address the steepness of the passenger car curves—could lead to changes in stringency as well 

as different impacts on different manufacturers. 

c. Risk of upsizing 

The steepness of the proposed curve for passenger cars presents a localized risk that 

manufacturers will respond in ways that compromise expected fuel savings. That is, although 

the constrained logistic curve has a steep region, that region does not cover a wide range of 

footprints. However, any attribute-based system involves the broader risk that manufacturers 

will shift toward vehicles with the lowest fuel economy targets. As mentioned above, the 

constrained logistic curve proposed by NHTSA provides an absolute floor. That is, even 

manufacturers discontinue all but the very largest known passenger cars and light trucks, they 

would still be required to meet CAFE standards no lower than the lower asymptote (on an mpg 

basis) of the constrained logistic curve. Also, for domestic passenger cars, EISA establishes a 

floor or “backstop” equal to 92% of the average required CAFE level for passenger cars. This 

backstop is discussed below in Section VI. 

It is difficult to assess the risk that manufacturers may shift the mix of vehicles enough to 

approach the EISA floor for domestic passenger cars, or to approach the lower asymptotes for 

light trucks or imported passenger cars. However, considering the footprint distribution of 

vehicles (as indicated by the various histograms and scatter plots shown above in this section) 
V-127 

expected to be covered by the proposed rule, NHTSA anticipates that manufacturers would not 

be able to approach these reductions in stringency without dramatically altering product mix. 

The agency doubts that manufacturers could do so unless consumer preferences also shift 

dramatically. 

NHTSA also notes that under attribute-based CAFE standards such as the agency is proposing 

today, shifts in consumer preferences could cause manufacturers’ required CAFE levels and, 

therefore, achieved fuel savings (and perhaps costs) to increase. For example, if changes in fuel 

prices combine with demographic and/or other factors to cause market preferences to shift 

significantly toward vehicles with smaller footprints, manufacturers shifting (relative to current 

estimates) in that direction will face higher required CAFE levels than the agency has estimated. 

C. Penetration of Technologies by Alternative 

Tables V-11a through V-11g show the penetration of technologies by year for passenger cars and 

Tables V-12a through V-12g show the penetration of technologies by year for light trucks for the 

alternatives. These tables are for the whole fleet combined, not by specific manufacturers. They allow 

the reader to see the progression of technologies applied as the standards get stricter. The baseline 

shown here is the adjusted baseline for MY 2011. 
V-128 

Table V-11a 

Penetration Rate of New Technologies to Passenger Cars – 25% Below Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 81% 100% 100% 100% 100% 

2. EFR 14% 20% 26% 38% 58% 71% 

3. VVTI 80% 80% 83% 88% 89% 91% 

4. VVTC 8% 9% 10% 13% 19% 28% 

5. VVTD 27% 26% 29% 31% 32% 34% 

6. DISP 4% 4% 7% 10% 15% 16% 

7. VVLTC 1% 1% 2% 5% 6% 9% 

8. VVLTD 12% 15% 18% 22% 22% 24% 

9. DISPO 2% 2% 2% 2% 3% 3% 

10. VVTO 6% 6% 6% 5% 5% 5% 

11. DOHC 6% 6% 5% 6% 7% 7% 

12. VVLTO 0% 0% 0% 0% 0% 0% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 13% 15% 18% 19% 21% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 8% 9% 9% 9% 11% 

18. DSLT 1% 3% 2% 2% 3% 5% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 22% 23% 21% 20% 18% 

22. ASL 7% 12% 21% 25% 22% 26% 

23. TORQ 4% 5% 6% 10% 16% 14% 

24. 6SP 26% 26% 26% 27% 22% 20% 

25. AMT 9% 9% 15% 19% 25% 30% 

26. CVT 11% 11% 10% 10% 10% 10% 

27. 6MAN 7% 8% 8% 8% 9% 9% 

28. IACC 20% 27% 27% 38% 39% 44% 

29. EPS 14% 16% 20% 27% 28% 34% 

30. 42V 0% 2% 1% 1% 2% 8% 

31. ROLL 5% 18% 29% 51% 62% 63% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 1% 1% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 12% 20% 31% 42% 47% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 2% 3% 3% 8% 10% 

40. IHYB 1% 1% 1% 1% 1% 2% 

41. 2HYB 0% 0% 0% 0% 1% 1% 

42. PHYB 3% 3% 3% 3% 3% 3% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-129 

Table V-11b 

Penetration Rate of New Technologies to Passenger Cars – Optimized 7% 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 27% 49% 69% 82% 82% 

3. VVTI 80% 80% 86% 91% 92% 91% 

4. VVTC 8% 9% 20% 28% 34% 34% 

5. VVTD 27% 27% 30% 34% 35% 36% 

6. DISP 4% 6% 11% 15% 20% 20% 

7. VVLTC 1% 1% 1% 4% 7% 15% 

8. VVLTD 12% 18% 27% 33% 34% 36% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 5% 5% 

11. DOHC 6% 6% 5% 6% 7% 7% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 15% 21% 24% 25% 28% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 10% 13% 14% 15% 19% 

18. DSLT 1% 3% 3% 3% 3% 4% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 21% 22% 19% 16% 15% 

22. ASL 7% 17% 29% 29% 21% 19% 

23. TORQ 4% 6% 9% 16% 15% 8% 

24. 6SP 26% 23% 21% 22% 17% 9% 

25. AMT 9% 13% 22% 27% 34% 43% 

26. CVT 11% 11% 12% 11% 12% 12% 

27. 6MAN 7% 8% 8% 8% 9% 9% 

28. IACC 20% 36% 41% 48% 51% 64% 

29. EPS 14% 21% 33% 41% 44% 51% 

30. 42V 0% 7% 14% 15% 19% 26% 

31. ROLL 5% 23% 42% 57% 62% 74% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 1% 1% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 18% 31% 40% 52% 56% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 3% 4% 5% 8% 11% 

40. IHYB 1% 1% 1% 1% 1% 2% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 3% 4% 3% 3% 4% 4% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-130 

Table V-11c 

Penetration Rate of New Technologies to Passenger Cars – 25% Above Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 33% 55% 73% 85% 87% 

3. VVTI 80% 79% 84% 88% 88% 87% 

4. VVTC 8% 14% 27% 37% 40% 41% 

5. VVTD 27% 27% 29% 33% 36% 36% 

6. DISP 4% 9% 15% 19% 23% 23% 

7. VVLTC 1% 1% 1% 4% 7% 13% 

8. VVLTD 12% 19% 29% 36% 38% 38% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 4% 4% 

11. DOHC 6% 6% 6% 7% 8% 8% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 14% 25% 29% 32% 34% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 12% 23% 27% 30% 31% 

18. DSLT 1% 5% 6% 6% 8% 9% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 19% 16% 14% 13% 13% 

22. ASL 7% 22% 31% 33% 24% 12% 

23. TORQ 4% 10% 14% 23% 21% 9% 

24. 6SP 26% 26% 25% 25% 18% 5% 

25. AMT 9% 14% 27% 29% 38% 50% 

26. CVT 11% 13% 13% 12% 12% 12% 

27. 6MAN 7% 8% 9% 9% 9% 10% 

28. IACC 20% 42% 56% 59% 60% 74% 

29. EPS 14% 24% 44% 51% 56% 59% 

30. 42V 0% 9% 22% 26% 32% 39% 

31. ROLL 5% 23% 48% 63% 86% 88% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 2% 2% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 18% 34% 45% 57% 68% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 1% 3% 3% 6% 9% 

40. IHYB 1% 1% 1% 1% 2% 2% 

41. 2HYB 0% 2% 4% 3% 4% 4% 

42. PHYB 3% 5% 5% 6% 7% 7% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-131 

Table V-11d 

Penetration Rate of New Technologies to Passenger Cars – 50% Above Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 33% 63% 83% 91% 91% 

3. VVTI 80% 79% 81% 84% 83% 82% 

4. VVTC 8% 17% 29% 37% 42% 41% 

5. VVTD 27% 26% 26% 30% 34% 34% 

6. DISP 4% 9% 17% 21% 25% 25% 

7. VVLTC 1% 1% 2% 5% 8% 21% 

8. VVLTD 12% 19% 29% 35% 37% 37% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 4% 4% 

11. DOHC 6% 6% 5% 5% 6% 7% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 15% 26% 31% 35% 44% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 12% 24% 27% 31% 38% 

18. DSLT 1% 5% 9% 10% 13% 14% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 19% 15% 9% 5% 5% 

22. ASL 7% 20% 29% 30% 18% 16% 

23. TORQ 4% 8% 12% 21% 18% 5% 

24. 6SP 26% 24% 23% 28% 19% 7% 

25. AMT 9% 16% 28% 32% 44% 56% 

26. CVT 11% 13% 12% 11% 10% 11% 

27. 6MAN 7% 8% 9% 9% 10% 10% 

28. IACC 20% 45% 64% 71% 72% 74% 

29. EPS 14% 26% 50% 62% 66% 67% 

30. 42V 0% 10% 26% 30% 38% 54% 

31. ROLL 5% 23% 56% 79% 85% 88% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 2% 2% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 22% 43% 53% 64% 67% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 1% 2% 2% 5% 7% 

40. IHYB 1% 1% 2% 2% 2% 3% 

41. 2HYB 0% 2% 4% 4% 5% 5% 

42. PHYB 3% 6% 8% 8% 12% 13% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-132 

 Table V-11e 

Penetration Rate of New Technologies to Passenger Cars – Optimized (3%) 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 37% 62% 81% 89% 89% 

3. VVTI 80% 77% 81% 84% 83% 82% 

4. VVTC 8% 19% 31% 38% 42% 42% 

5. VVTD 27% 26% 27% 30% 34% 34% 

6. DISP 4% 10% 18% 21% 25% 25% 

7. VVLTC 1% 1% 2% 5% 12% 25% 

8. VVLTD 12% 18% 31% 36% 38% 38% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 4% 4% 

11. DOHC 6% 6% 5% 5% 6% 7% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 20% 33% 37% 41% 52% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 16% 29% 34% 37% 49% 

18. DSLT 1% 7% 9% 11% 13% 14% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 12% 5% 3% 1% 1% 

22. ASL 7% 33% 30% 32% 17% 4% 

23. TORQ 4% 14% 17% 23% 14% 2% 

24. 6SP 26% 30% 27% 28% 15% 2% 

25. AMT 9% 17% 36% 39% 54% 67% 

26. CVT 11% 14% 14% 12% 12% 12% 

27. 6MAN 7% 8% 9% 9% 10% 10% 

28. IACC 20% 51% 62% 68% 75% 77% 

29. EPS 14% 30% 54% 62% 66% 67% 

30. 42V 0% 14% 32% 35% 45% 60% 

31. ROLL 5% 33% 56% 74% 88% 88% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 2% 2% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 26% 41% 50% 58% 61% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 2% 4% 4% 6% 8% 

40. IHYB 1% 1% 2% 2% 2% 3% 

41. 2HYB 0% 3% 5% 5% 6% 8% 

42. PHYB 3% 6% 8% 8% 12% 13% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-133 

Table V-11f 

Penetration Rate of New Technologies to Passenger Cars – TC = TB 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 37% 62% 81% 89% 89% 

3. VVTI 80% 77% 81% 84% 83% 82% 

4. VVTC 8% 19% 31% 38% 42% 42% 

5. VVTD 27% 26% 27% 30% 34% 34% 

6. DISP 4% 10% 18% 21% 25% 25% 

7. VVLTC 1% 1% 2% 5% 12% 25% 

8. VVLTD 12% 18% 31% 36% 38% 38% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 4% 4% 

11. DOHC 6% 6% 5% 5% 6% 7% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 20% 33% 37% 41% 52% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 16% 29% 34% 37% 49% 

18. DSLT 1% 7% 9% 11% 13% 14% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 12% 5% 3% 1% 1% 

22. ASL 7% 33% 30% 32% 17% 4% 

23. TORQ 4% 14% 17% 23% 14% 2% 

24. 6SP 26% 30% 27% 28% 15% 2% 

25. AMT 9% 17% 36% 39% 54% 67% 

26. CVT 11% 14% 14% 12% 12% 12% 

27. 6MAN 7% 8% 9% 9% 10% 10% 

28. IACC 20% 51% 62% 68% 75% 77% 

29. EPS 14% 30% 54% 62% 66% 67% 

30. 42V 0% 14% 32% 35% 45% 60% 

31. ROLL 5% 33% 56% 74% 88% 88% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 0% 1% 2% 2% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 26% 41% 50% 58% 61% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 2% 4% 4% 6% 8% 

40. IHYB 1% 1% 2% 2% 2% 3% 

41. 2HYB 0% 3% 5% 5% 6% 8% 

42. PHYB 3% 6% 8% 8% 12% 13% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-134 

 Table V-11g 

Penetration Rate of New Technologies to Passenger Cars – Tech exhaustion 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 78% 93% 100% 100% 100% 100% 

2. EFR 14% 37% 66% 88% 96% 96% 

3. VVTI 80% 76% 77% 79% 74% 72% 

4. VVTC 8% 18% 29% 37% 36% 35% 

5. VVTD 27% 26% 26% 29% 33% 34% 

6. DISP 4% 10% 18% 22% 26% 27% 

7. VVLTC 1% 1% 2% 5% 8% 22% 

8. VVLTD 12% 17% 33% 40% 41% 43% 

9. DISPO 2% 3% 4% 3% 3% 3% 

10. VVTO 6% 6% 6% 5% 4% 4% 

11. DOHC 6% 6% 5% 5% 5% 7% 

12. VVLTO 0% 1% 2% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 11% 18% 36% 42% 50% 61% 

15. DSLS 0% 0% 0% 0% 0% 0% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 8% 15% 32% 38% 46% 58% 

18. DSLT 1% 9% 13% 15% 22% 24% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 22% 12% 5% 2% 0% 0% 

22. ASL 7% 33% 30% 30% 15% 2% 

23. TORQ 4% 14% 17% 24% 15% 2% 

24. 6SP 26% 30% 27% 28% 15% 2% 

25. AMT 9% 17% 36% 40% 56% 69% 

26. CVT 11% 13% 13% 11% 11% 11% 

27. 6MAN 7% 8% 10% 10% 12% 12% 

28. IACC 20% 59% 75% 84% 88% 88% 

29. EPS 14% 34% 66% 76% 87% 88% 

30. 42V 0% 14% 40% 46% 65% 81% 

31. ROLL 5% 33% 57% 80% 88% 88% 

32. LDB 21% 21% 21% 21% 21% 21% 

33. SAXU 0% 0% 1% 2% 3% 3% 

34. SAXL 0% 0% 0% 0% 0% 0% 

35. AERO 7% 26% 41% 53% 60% 69% 

36. MS1 0% 0% 0% 0% 0% 0% 

37. MS2 0% 0% 0% 0% 0% 0% 

38. MS5 0% 0% 0% 0% 0% 0% 

39. ISGO 0% 1% 1% 1% 2% 4% 

40. IHYB 1% 1% 2% 2% 3% 3% 

41. 2HYB 0% 3% 9% 9% 11% 12% 

42. PHYB 3% 7% 11% 11% 16% 19% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-135 

Table V-12a 

Penetration Rate of New Technologies to Light Trucks – 25% Below Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 93% 92% 90% 

3. VVTI 63% 66% 69% 71% 72% 73% 

4. VVTC 6% 14% 30% 39% 36% 35% 

5. VVTD 17% 18% 20% 25% 30% 30% 

6. DISP 13% 19% 31% 43% 44% 45% 

7. VVLTC 0% 0% 0% 2% 2% 3% 

8. VVLTD 10% 11% 14% 20% 20% 21% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 9% 13% 19% 18% 17% 

11. DOHC 11% 11% 18% 19% 21% 22% 

12. VVLTO 1% 1% 1% 1% 1% 1% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 12% 19% 23% 26% 30% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 10% 19% 21% 21% 21% 

18. DSLT 0% 0% 0% 0% 0% 0%

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0%

21. 5SP 34% 24% 13% 10% 12% 11% 

22. ASL 25% 41% 43% 44% 46% 47% 

23. TORQ 2% 11% 19% 26% 28% 26% 

24. 6SP 36% 40% 40% 36% 36% 38% 

25. AMT 11% 19% 33% 47% 45% 44% 

26. CVT 4% 4% 3% 3% 3% 3% 

27. 6MAN 1% 1% 2% 2% 2% 2% 

28. IACC 28% 50% 63% 71% 71% 71% 

29. EPS 10% 16% 36% 58% 58% 57% 

30. 42V 5% 5% 14% 27% 29% 29% 

31. ROLL 7% 28% 31% 34% 34% 34% 

32. LDB 26% 32% 35% 36% 36% 36% 

33. SAXU 0% 0% 1% 3% 3% 3% 

34. SAXL 1% 1% 8% 12% 12% 12% 

35. AERO 10% 18% 38% 62% 60% 62% 

36. MS1 1% 1% 6% 6% 6% 6% 

37. MS2 1% 1% 6% 6% 6% 6% 

38. MS5 1% 1% 6% 6% 6% 6% 

39. ISGO 2% 2% 3% 5% 5% 5% 

40. IHYB 1% 3% 5% 7% 7% 7% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 3% 3% 3% 3% 3% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-136 

Table V-12b 

Penetration Rate of New Technologies to Light Trucks – Optimized 7% 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 92% 91% 93% 

3. VVTI 63% 66% 69% 71% 71% 73% 

4. VVTC 6% 15% 31% 39% 35% 38% 

5. VVTD 17% 18% 22% 26% 30% 31% 

6. DISP 13% 22% 35% 46% 47% 49% 

7. VVLTC 0% 0% 0% 2% 2% 3% 

8. VVLTD 10% 11% 15% 23% 23% 23% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 10% 13% 19% 18% 17% 

11. DOHC 11% 11% 18% 19% 21% 22% 

12. VVLTO 1% 1% 1% 1% 1% 1% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 12% 24% 32% 34% 39% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 10% 22% 30% 30% 30% 

18. DSLT 0% 0% 0% 0% 0% 0% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 10% 12% 9% 

22. ASL 25% 41% 42% 43% 39% 36% 

23. TORQ 2% 11% 24% 33% 29% 29% 

24. 6SP 36% 40% 38% 36% 29% 28% 

25. AMT 11% 19% 36% 48% 53% 57% 

26. CVT 4% 4% 3% 3% 3% 3% 

27. 6MAN 1% 1% 2% 2% 2% 2% 

28. IACC 28% 57% 70% 80% 84% 86% 

29. EPS 10% 22% 43% 66% 69% 74% 

30. 42V 5% 8% 23% 44% 48% 50% 

31. ROLL 7% 28% 31% 34% 34% 34% 

32. LDB 26% 35% 37% 37% 37% 37% 

33. SAXU 0% 0% 1% 3% 3% 3% 

34. SAXL 1% 1% 9% 12% 13% 14% 

35. AERO 10% 18% 38% 60% 68% 80% 

36. MS1 1% 2% 7% 13% 13% 14% 

37. MS2 1% 2% 7% 10% 11% 11% 

38. MS5 1% 1% 6% 6% 7% 7% 

39. ISGO 2% 2% 3% 4% 5% 7% 

40. IHYB 1% 3% 5% 8% 11% 15% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 3% 3% 3% 4% 4% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-137 

Table V-12c 

Penetration Rate of New Technologies to Light Trucks – 25% Above Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 93% 92% 90% 

3. VVTI 63% 66% 69% 71% 72% 73% 

4. VVTC 6% 14% 30% 39% 36% 35% 

5. VVTD 17% 18% 20% 25% 30% 30% 

6. DISP 13% 19% 31% 43% 44% 45% 

7. VVLTC 0% 0% 0% 2% 2% 3% 

8. VVLTD 10% 11% 14% 20% 20% 21% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 9% 13% 19% 18% 17% 

11. DOHC 11% 11% 18% 19% 21% 22% 

12. VVLTO 1% 1% 1% 1% 1% 1% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 12% 19% 23% 26% 30% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 10% 19% 21% 21% 21% 

18. DSLT 0% 0% 0% 0% 0% 0% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 10% 12% 11% 

22. ASL 25% 41% 43% 44% 46% 47% 

23. TORQ 2% 11% 19% 26% 28% 26% 

24. 6SP 36% 40% 40% 36% 36% 38% 

25. AMT 11% 19% 33% 47% 45% 44% 

26. CVT 4% 4% 3% 3% 3% 3% 

27. 6MAN 1% 1% 2% 2% 2% 2% 

28. IACC 28% 50% 63% 71% 71% 71% 

29. EPS 10% 16% 36% 58% 58% 57% 

30. 42V 5% 5% 14% 27% 29% 29% 

31. ROLL 7% 28% 31% 34% 34% 34% 

32. LDB 26% 32% 35% 36% 36% 36% 

33. SAXU 0% 0% 1% 3% 3% 3% 

34. SAXL 1% 1% 8% 12% 12% 12% 

35. AERO 10% 18% 38% 62% 60% 62% 

36. MS1 1% 1% 6% 6% 6% 6% 

37. MS2 1% 1% 6% 6% 6% 6% 

38. MS5 1% 1% 6% 6% 6% 6% 

39. ISGO 2% 2% 3% 5% 5% 5% 

40. IHYB 1% 3% 5% 7% 7% 7% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 3% 3% 3% 3% 3% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-138 

Table V-12d 

Penetration Rate of New Technologies to Light Trucks – 50% Above Optimized 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 89% 89% 91% 

3. VVTI 63% 66% 65% 67% 65% 62% 

4. VVTC 6% 15% 30% 33% 29% 34% 

5. VVTD 17% 19% 21% 22% 26% 25% 

6. DISP 13% 22% 36% 44% 46% 50% 

7. VVLTC 0% 3% 2% 5% 6% 5% 

8. VVLTD 10% 11% 13% 23% 23% 24% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 10% 13% 19% 18% 17% 

11. DOHC 11% 11% 18% 19% 22% 21% 

12. VVLTO 1% 1% 1% 3% 3% 3% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 16% 25% 36% 38% 41% 

15. DSLS 3% 5% 6% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 10% 22% 32% 33% 37% 

18. DSLT 0% 0% 4% 5% 8% 13% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 11% 12% 7% 

22. ASL 25% 41% 41% 41% 40% 33% 

23. TORQ 2% 11% 22% 28% 22% 23% 

24. 6SP 36% 40% 37% 37% 28% 26% 

25. AMT 11% 19% 37% 45% 53% 60% 

26. CVT 4% 4% 3% 3% 3% 2% 

27. 6MAN 1% 1% 2% 2% 2% 2% 

28. IACC 28% 61% 78% 85% 96% 97% 

29. EPS 10% 26% 53% 73% 78% 86% 

30. 42V 5% 12% 30% 51% 62% 71% 

31. ROLL 7% 28% 31% 33% 34% 34% 

32. LDB 26% 36% 38% 39% 39% 39% 

33. SAXU 0% 0% 4% 11% 14% 17% 

34. SAXL 1% 3% 10% 14% 14% 14% 

35. AERO 10% 18% 38% 56% 64% 79% 

36. MS1 1% 3% 8% 13% 17% 17% 

37. MS2 1% 2% 7% 13% 17% 17% 

38. MS5 1% 2% 7% 13% 14% 15% 

39. ISGO 2% 2% 3% 4% 5% 6% 

40. IHYB 1% 3% 7% 9% 12% 13% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 3% 4% 4% 7% 10% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-139 

Table V-12e 

Penetration Rate of New Technologies to Light Trucks – Optimized (3%) 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 95% 94% 95% 

3. VVTI 63% 66% 69% 71% 71% 72% 

4. VVTC 6% 15% 32% 39% 36% 38% 

5. VVTD 17% 19% 23% 26% 31% 31% 

6. DISP 13% 22% 36% 49% 50% 53% 

7. VVLTC 0% 0% 0% 2% 2% 3% 

8. VVLTD 10% 11% 15% 24% 24% 28% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 10% 13% 19% 18% 17% 

11. DOHC 11% 11% 18% 18% 20% 21% 

12. VVLTO 1% 1% 1% 2% 2% 2% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 12% 23% 33% 35% 41% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 10% 20% 29% 29% 34% 

18. DSLT 0% 0% 0% 1% 3% 4% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 10% 12% 7% 

22. ASL 25% 41% 42% 42% 37% 30% 

23. TORQ 2% 11% 24% 31% 27% 23% 

24. 6SP 36% 40% 38% 33% 26% 24% 

25. AMT 11% 19% 36% 50% 56% 63% 

26. CVT 4% 4% 3% 3% 3% 2% 

27. 6MAN 1% 1% 2% 2% 2% 2% 

28. IACC 28% 57% 70% 80% 87% 90% 

29. EPS 10% 22% 43% 68% 71% 79% 

30. 42V 5% 8% 23% 45% 49% 57% 

31. ROLL 7% 28% 31% 34% 34% 34% 

32. LDB 26% 35% 37% 37% 38% 38% 

33. SAXU 0% 0% 1% 8% 9% 9% 

34. SAXL 1% 1% 9% 12% 13% 14% 

35. AERO 10% 18% 38% 60% 68% 82% 

36. MS1 1% 2% 7% 13% 13% 14% 

37. MS2 1% 2% 7% 13% 13% 14% 

38. MS5 1% 1% 6% 12% 12% 13% 

39. ISGO 2% 2% 3% 4% 5% 7% 

40. IHYB 1% 3% 5% 8% 12% 14% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 3% 3% 3% 4% 4% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-140 

Table V-12f 

Penetration Rate of New Technologies to Light Trucks – TC = TB 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 93% 94% 94% 

3. VVTI 63% 61% 59% 61% 58% 56% 

4. VVTC 6% 13% 27% 30% 24% 26% 

5. VVTD 17% 16% 19% 22% 25% 27% 

6. DISP 13% 23% 37% 43% 44% 48% 

7. VVLTC 0% 1% 3% 7% 8% 11% 

8. VVLTD 10% 11% 16% 25% 25% 26% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 10% 13% 19% 18% 17% 

11. DOHC 11% 8% 16% 23% 27% 30% 

12. VVLTO 1% 1% 1% 3% 3% 3% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 15% 27% 45% 50% 58% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 13% 27% 43% 46% 53% 

18. DSLT 0% 4% 10% 12% 16% 19% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 11% 12% 7% 

22. ASL 25% 41% 41% 41% 41% 33% 

23. TORQ 2% 11% 22% 29% 22% 22% 

24. 6SP 36% 40% 37% 37% 29% 25% 

25. AMT 11% 19% 37% 45% 53% 61% 

26. CVT 4% 4% 3% 3% 3% 2% 

27. 6MAN 1% 1% 2% 2% 3% 3% 

28. IACC 28% 63% 79% 85% 99% 99% 

29. EPS 10% 28% 55% 76% 79% 89% 

30. 42V 5% 14% 34% 54% 67% 79% 

31. ROLL 7% 28% 31% 33% 34% 34% 

32. LDB 26% 36% 38% 39% 39% 39% 

33. SAXU 0% 0% 7% 15% 20% 22% 

34. SAXL 1% 3% 10% 14% 14% 14% 

35. AERO 10% 18% 38% 56% 64% 79% 

36. MS1 1% 3% 8% 13% 17% 17% 

37. MS2 1% 3% 8% 13% 17% 17% 

38. MS5 1% 3% 8% 13% 17% 17% 

39. ISGO 2% 2% 2% 2% 3% 5% 

40. IHYB 1% 3% 4% 5% 5% 5% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 4% 8% 10% 16% 20% 

43. PLUG 0% 0% 0% 0% 0% 0% 
V-141 

Table V-12g 

Penetration Rate of New Technologies to Light Trucks – Tech exhaustion 

 Baseline MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

1. LUB 73% 85% 100% 100% 100% 100% 

2. EFR 59% 71% 79% 95% 96% 95% 

3. VVTI 63% 61% 59% 58% 56% 55% 

4. VVTC 6% 13% 27% 33% 29% 28% 

5. VVTD 17% 16% 19% 22% 25% 27% 

6. DISP 13% 23% 37% 51% 52% 55% 

7. VVLTC 0% 1% 3% 9% 11% 14% 

8. VVLTD 10% 11% 16% 27% 26% 27% 

9. DISPO 14% 16% 14% 19% 18% 17% 

10. VVTO 9% 10% 13% 19% 18% 17% 

11. DOHC 11% 8% 16% 23% 27% 30% 

12. VVLTO 1% 1% 1% 3% 3% 3% 

13. CVA 0% 0% 0% 0% 0% 0% 

14. SIDI 12% 15% 27% 52% 58% 67% 

15. DSLS 3% 5% 5% 5% 5% 5% 

16. LBDI 0% 0% 0% 0% 0% 0% 

17. TURB 10% 13% 27% 51% 56% 63% 

18. DSLT 0% 4% 10% 15% 18% 20% 

19. HCCI 0% 0% 0% 0% 0% 0% 

20. DSLH 0% 0% 0% 0% 0% 0% 

21. 5SP 34% 24% 13% 5% 6% 3% 

22. ASL 25% 41% 41% 38% 31% 23% 

23. TORQ 2% 11% 22% 31% 25% 20% 

24. 6SP 36% 40% 37% 34% 26% 21% 

25. AMT 11% 19% 37% 55% 63% 71% 

26. CVT 4% 4% 3% 2% 2% 2% 

27. 6MAN 1% 1% 2% 3% 3% 3% 

28. IACC 28% 63% 79% 92% 99% 99% 

29. EPS 10% 28% 55% 88% 92% 98% 

30. 42V 5% 14% 34% 68% 81% 93% 

31. ROLL 7% 28% 31% 34% 34% 34% 

32. LDB 26% 36% 38% 39% 39% 39% 

33. SAXU 0% 0% 7% 17% 21% 22% 

34. SAXL 1% 3% 10% 15% 15% 15% 

35. AERO 10% 18% 38% 61% 68% 83% 

36. MS1 1% 3% 8% 17% 21% 21% 

37. MS2 1% 3% 8% 17% 21% 21% 

38. MS5 1% 3% 8% 17% 21% 21% 

39. ISGO 2% 2% 2% 2% 2% 3% 

40. IHYB 1% 3% 4% 5% 5% 7% 

41. 2HYB 0% 1% 1% 1% 1% 1% 

42. PHYB 2% 5% 9% 12% 16% 20% 

43. PLUG 0% 0% 0% 0% 0% 0% 
VI-1

VI. MANUFACTURER SPECIFIC CAFE CAPABILITIES 

Table VI-1a for passenger cars and Table VI-2a for light trucks shows the CAFE product plans 

for each of the manufacturers, based on the manufacturer’s plans without taking into account any 

alternative or dual fuel vehicle attributes. 

Table VI-1b for passenger cars and Table VI-2b for light trucks shows the ADJUSTED 

BASELINE. Note that when we do cost and benefit analyses, we use the ADJUSTED 

BASELINE throughout the analysis. The adjusted baseline assumes for the analysis that each 

manufacturer, below the MY 2010 standard applicable to that manufacturer, (except Ferrari, 

Lotus, Maserati, Mercedes, Porsche and Volkswagen) would apply technology to achieve the 

MY 2010 standard. Those mpg levels of those manufacturers with product plans above the MY 

2010 standard, or above their required reform level standard in any model year, are retained for 

the adjusted baseline. Our rationale for this adjustment of the baseline is that the costs and 

benefits of achieving MY 2010 mpg levels for light trucks have already been analyzed and 

estimated in previous analyses. The methodology in this analysis is to apply technologies to the 

manufacturers’ plans and increase them to the adjusted baseline. The costs of these technologies 

are estimated, but they are not considered part of this rule. We then estimate the costs and 

benefits of going from the adjusted baseline to the level of the alternatives.134 

The required standard levels for only the proposal are shown in Table VI-1d for passenger cars 

and VI-2d for light trucks. For the other tables in the group from Tables VI-1c through VI-1j for 

passenger cars and Tables VI-2c through VI-2j for light trucks shows what we believe the 

manufacturers’ fuel economy could be for “meeting” the alternative levels analyzed in this 

analysis. They include in some cases manufacturers’ plans at levels higher than the alternative 

standards would require. Note that not all manufacturers are assumed to attempt to “meet” the 

alternatives. We assume that Ferrari, Lotus, Maserati, Mercedes, Porsche and Volkswagen 

would not meet these levels because, for them, the cost of meeting these levels is more than the 

cost of paying penalties. These manufacturers have shown, in the past, the willingness to pay 

penalties rather than spend more money to improve the fuel economy of their products. 

The agency has performed an analysis of how manufacturers could respond to changes in the 

proposed CAFE levels. The “Technology Application Analysis” (or the “Volpe Analysis”) uses 

a technology application algorithm to systematically apply consistent cost and performance 

assumptions to the entire industry, as well as consistent assumptions regarding economic 

decision-making by manufacturers. The resulting computer model (the CAFE Compliance and 

Effects Model), developed by technical staff of the DOT Volpe National Transportation Systems 

Center in consultation with NHTSA staff, is used to help estimate the overall economic impact of 

the alternative CAFE standards. The Volpe analysis shows the economic impact of the standards 

in terms of increases in new vehicle prices on a manufacturer-wide, industry-wide, and average 

per-vehicle basis. Based on these estimates and corresponding estimates of net economic and 

 

134 Some manufacturer’s plans are above the level of the standard already and are assumed to remain at that level. 

Some manufacturer’s levels go slightly above the proposed mark for them since some technologies are applied to all 

models of a particular manufacturer so that the exact level for each manufacturer may be slightly higher than the 

level of the standard and costs and benefits are estimated to that level. 
VI-2

other benefits, the agency is able to consider alternatives that are economically practicable and 

technologically feasible. 

We note that the Volpe model has been updated and refined with respect to its representation of 

some fuel-saving technologies, but the model remains fundamentally unchanged. The model has 

been peer reviewed. The model documentation, including a description of the input assumptions 

and process, as well as peer review reports, was made available in the rulemaking docket for the 

August 2005 NPRM.135

Our analyses of the potential effects of alternative CAFE standards were founded on two major 

elements: (1) projections of the technical characteristics and sales volumes of future product 

offerings and (2) estimates of the applicability and incremental cost and fuel savings associated 

with different hardware changes—technologies—that might be utilized in response to alternative 

CAFE standards. 

 

 

135 See Docket Nos. NHTSA-20005-22223-3, 4, 5. 
VI-3

Table VI-1a 

Manufacturers Production Plans 

Estimated mpg 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

26.9 

 

26.9 

 

26.9 

 

26.9 

 

26.9 

Chrysler 

 

28.2 

 

28.2 

 

31.3 

 

31.2 

 

31.3 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

28.2 

 

30.5 

 

30.5 

 

30.5 

 

30.5 

Fuji (Subaru) 

 

27.1 

 

27.1 

 

27.1 

 

27.1 

 

27.1 

General Motors 

 

28.2 

 

27.8 

 

27.8 

 

27.8 

 

27.8 

Honda 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

Hyundai 

 

32.7 

 

32.7 

 

32.7 

 

32.7 

 

32.7 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

25.1 

 

25.1 

 

25.1 

 

25.1 

 

25.1 

Mitsubishi 

 

29.8 

 

30.2 

 

30.4 

 

30.6 

 

30.6 

Nissan 

 

30.6 

 

31.2 

 

31.2 

 

31.2 

 

31.2 

Porsche 

 

24.5 

 

24.5 

 

24.5 

 

24.5 

 

24.5 

Suzuki 

 

29.6 

 

29.6 

 

29.6 

 

29.6 

 

29.6 

Toyota 

 

34.3 

 

34.3 

 

34.4 

 

34.4 

 

34.4 

Volkswagen 

 

28.8 

 

28.8 

 

28.8 

 

28.8 

 

28.8 

Total/Average 

 

30.0 

 

30.3 

 

30.5 

 

30.5 

 

30.6 
VI-4

Table VI-1b 

Adjusted Baseline 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

27.5 

 

27.5 

 

27.5 

 

27.5 

 

27.5 

Chrysler 

 

28.2 

 

28.2 

 

31.3 

 

31.2 

 

31.3 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

28.2 

 

30.5 

 

30.5 

 

30.5 

 

30.5 

Fuji (Subaru) 

 

27.6 

 

27.6 

 

27.6 

 

27.6 

 

27.6 

General Motors 

 

28.2 

 

27.8 

 

27.8 

 

27.8 

 

27.8 

Honda 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

Hyundai 

 

32.7 

 

32.7 

 

32.7 

 

32.7 

 

32.7 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

27.5 

 

27.5 

Mitsubishi 

 

29.8 

 

30.2 

 

30.4 

 

30.6 

 

30.6 

Nissan 

 

30.6 

 

31.2 

 

31.2 

 

31.2 

 

31.2 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

29.6 

 

29.6 

 

29.6 

 

29.6 

 

29.6 

Toyota 

 

34.3 

 

34.3 

 

34.4 

 

34.4 

 

34.4 

Volkswagen 

 

28.8 

 

28.8 

 

28.8 

 

28.8 

 

28.8 

Total/Average 

 

30.1 

 

30.4 

 

30.7 

 

30.7 

 

30.7 
VI-5

Table VI-1c 

Estimated Achievable Fuel Economy Levels 

25% Below Optimized 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

28.2 

 

28.2 

 

31.3 

 

31.2 

 

32.0 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.4 

 

31.4 

 

31.5 

 

32.5 

 

33.7 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

28.6 

 

29.5 

 

30.4 

 

31.9 

 

33.0 

Honda 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

 

34.8 

Hyundai 

 

32.7 

 

32.7 

 

33.5 

 

34.5 

 

35.6 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

31.2 

 

32.2 

 

33.4 

 

34.7 

 

35.8 

Nissan 

 

30.6 

 

31.2 

 

31.9 

 

32.9 

 

34.0 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

39.4 

Toyota 

 

34.3 

 

34.3 

 

34.4 

 

34.4 

 

34.4 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

30.5 

 

31.2 

 

31.9 

 

32.8 

 

33.5 
VI-6

Table VI-1d 

Required Fuel Economy Levels 

Proposed Optimized (7%) Standard 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

33.3 

 

35.0 

 

36.0 

 

36.8 

 

37.7 

Chrysler 

 

28.7 

 

29.3 

 

32.2 

 

32.6 

 

33.6 

Ferrari 

 

30.4 

 

32.0 

 

33.1 

 

33.9 

 

34.9 

Ford 

 

31.0 

 

32.7 

 

33.7 

 

34.5 

 

35.5 

Fuji (Subaru) 

 

36.9 

 

38.7 

 

39.6 

 

40.1 

 

40.8 

General Motors 

 

30.0 

 

31.7 

 

32.8 

 

33.7 

 

34.7 

Honda 

 

32.1 

 

33.8 

 

34.8 

 

35.5 

 

36.4 

Hyundai 

 

33.4 

 

35.1 

 

36.0 

 

36.7 

 

37.5 

Lotus 

 

38.1 

 

40.0 

 

40.8 

 

41.2 

 

41.7 

Maserati 

 

28.9 

 

30.6 

 

31.8 

 

32.8 

 

34.0 

Mercedes 

 

31.7 

 

33.3 

 

34.4 

 

35.3 

 

36.2 

Mitsubishi 

 

33.0 

 

35.1 

 

35.9 

 

37.0 

 

37.9 

Nissan 

 

31.2 

 

33.2 

 

34.2 

 

35.0 

 

35.9 

Porsche 

 

37.6 

 

39.4 

 

40.3 

 

40.7 

 

41.3 

Suzuki 

 

37.3 

 

39.2 

 

40.1 

 

40.6 

 

41.2 

Toyota 

 

30.1 

 

31.5 

 

32.7 

 

33.6 

 

34.6 

Volkswagen 

 

35.4 

 

37.2 

 

38.2 

 

38.8 

 

39.5 

Total/Average 

 

31.2 

 

32.8 

 

34.0 

 

34.8 

 

35.7 
VI-7

 Table VI-1e 

Estimated Achievable Fuel Economy Levels 

Proposed Optimized (7%) Standard 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

28.7 

 

29.3 

 

32.3 

 

32.6 

 

33.1 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

32.7 

 

33.7 

 

34.5 

 

35.6 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General Motors 

 

30.0 

 

31.7 

 

32.3 

 

33.7 

 

34.7 

Honda 

 

34.8 

 

34.8 

 

34.8 

 

35.5 

 

36.4 

Hyundai 

 

33.4 

 

35.1 

 

36.0 

 

36.7 

 

37.1 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

33.5 

 

35.1 

 

35.9 

 

37.0 

 

37.9 

Nissan 

 

31.2 

 

33.2 

 

34.2 

 

35.0 

 

35.9 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

41.8 

Toyota 

 

34.3 

 

34.3 

 

34.4 

 

34.4 

 

34.6 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

31.0 

 

32.3 

 

33.1 

 

33.9 

 

34.7 
VI-8

Table VI-1f 

Estimated Achievable Fuel Economy Levels 

25% Above Optimized 

Passenger Cars 

(mpg) 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

30.2 

 

31.4 

 

34.2 

 

34.4 

 

34.1 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

33.1 

 

34.3 

 

35.8 

 

37.3 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

30.4 

 

32.9 

 

33.6 

 

35.6 

 

36.4 

Honda 

 

34.8 

 

36.4 

 

37.0 

 

37.7 

 

38.3 

Hyundai 

 

35.6 

 

37.9 

 

38.5 

 

39.0 

 

39.3 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

34.3 

 

37.3 

 

38.6 

 

39.3 

 

39.6 

Nissan 

 

32.8 

 

35.7 

 

36.5 

 

37.0 

 

37.7 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

45.2 

Toyota 

 

34.3 

 

34.3 

 

34.6 

 

35.5 

 

36.3 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

31.5 

 

33.3 

 

34.2 

 

35.3 

 

36.1 
VI-9

Table VI-1g 

Estimated Achievable Fuel Economy Levels 

50% Above Optimized 

Passenger Cars 

 (mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

31.0 

 

33.3 

 

36.0 

 

36.1 

 

35.2 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

33.1 

 

34.3 

 

35.8 

 

39.2 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

30.4 

 

32.9 

 

33.6 

 

35.9 

 

37.4 

Honda 

 

35.5 

 

38.2 

 

39.2 

 

40.6 

 

40.8 

Hyundai 

 

37.0 

 

41.2 

 

41.5 

 

42.0 

 

42.4 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

34.3 

 

37.3 

 

41.1 

 

41.3 

 

41.9 

Nissan 

 

32.9 

 

35.9 

 

38.0 

 

39.4 

 

40.0 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

49.8 

Toyota 

 

34.3 

 

36.1 

 

36.7 

 

37.1 

 

37.7 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

31.7 

 

34.0 

 

35.1 

 

36.4 

 

37.6 
VI-10

Table VI-1h 

Estimated Achievable Fuel Economy Levels 

 Optimized (3%) 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

31.0 

 

34.1 

 

36.7 

 

37.6 

 

36.4 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

33.1 

 

34.3 

 

35.8 

 

39.8 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

30.4 

 

32.9 

 

33.6 

 

35.9 

 

37.4 

Honda 

 

38.5 

 

40.3 

 

40.6 

 

41.9 

 

42.0 

Hyundai 

 

39.6 

 

42.5 

 

42.5 

 

43.5 

 

43.7 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

34.3 

 

37.3 

 

41.1 

 

41.3 

 

41.9 

Nissan 

 

32.9 

 

35.9 

 

38.0 

 

39.9 

 

40.5 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

49.8 

Toyota 

 

35.6 

 

37.7 

 

37.9 

 

39.0 

 

39.2 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

32.2 

 

34.5 

 

35.5 

 

37.0 

 

38.2 
VI-11

Table VI-1i 

Estimated Achievable Fuel Economy Levels 

 Total Cost = Total Benefit 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

31.0 

 

34.4 

 

38.0 

 

38.4 

 

36.8 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

33.1 

 

34.3 

 

35.8 

 

39.8 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

30.4 

 

32.9 

 

33.6 

 

35.9 

 

37.4 

Honda 

 

39.0 

 

40.6 

 

41.0 

 

43.7 

 

43.8 

Hyundai 

 

39.6 

 

44.2 

 

45.0 

 

47.6 

 

47.6 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

34.3 

 

37.3 

 

41.1 

 

41.3 

 

41.9 

Nissan 

 

32.9 

 

35.9 

 

38.0 

 

39.9 

 

40.5 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

51.6 

Toyota 

 

36.0 

 

40.7 

 

40.9 

 

40.9 

 

41.0 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

32.3 

 

35.0 

 

36.1 

 

37.6 

 

38.8 
VI-12

Table VI-1j 

Estimated Achievable Fuel Economy Levels 

 Technology Exhaustion 

Passenger Cars 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.7 

 

29.0 

 

29.6 

 

30.1 

 

30.1 

Chrysler 

 

31.0 

 

34.4 

 

38.0 

 

38.4 

 

36.8 

Ferrari 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

 

14.6 

Ford 

 

29.5 

 

33.1 

 

34.3 

 

35.8 

 

39.8 

Fuji (Subaru) 

 

28.6 

 

28.7 

 

29.8 

 

34.1 

 

37.5 

General 

Motors 

 

30.4 

 

32.9 

 

33.6 

 

35.9 

 

37.4 

Honda 

 

39.7 

 

41.4 

 

41.7 

 

44.5 

 

44.7 

Hyundai 

 

39.6 

 

44.2 

 

45.0 

 

48.5 

 

48.7 

Lotus 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

 

29.2 

Maserati 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

 

15.9 

Mercedes 

 

26.2 

 

27.0 

 

27.4 

 

29.8 

 

30.1 

Mitsubishi 

 

34.3 

 

37.3 

 

41.1 

 

41.3 

 

41.9 

Nissan 

 

32.9 

 

35.9 

 

38.0 

 

39.9 

 

40.5 

Porsche 

 

25.4 

 

25.5 

 

25.5 

 

26.5 

 

26.5 

Suzuki 

 

31.3 

 

34.8 

 

34.8 

 

37.6 

 

51.6 

Toyota 

 

36.0 

 

42.0 

 

44.5 

 

46.9 

 

48.7 

Volkswagen 

 

29.5 

 

29.7 

 

31.2 

 

31.3 

 

32.3 

Total/Average 

 

32.3 

 

35.2 

 

36.6 

 

38.5 

 

39.9 
VI-13

Table VI-2a 

Manufacturers Production Plans 

Estimated mpg 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

21.3 

 

21.3 

 

21.3 

 

21.3 

 

21.3 

Chrysler 

 

23.5 

 

23.8 

 

24.4 

 

25.0 

 

25.4 

Ferrari 

Ford 

 

23.6 

 

24.1 

 

25.3 

 

25.3 

 

25.3 

Fuji (Subaru) 

 

27.1 

 

27.1 

 

27.1 

 

27.1 

 

27.0 

General Motors 

 

21.6 

 

21.8 

 

21.8 

 

21.8 

 

21.8 

Honda 

 

25.0 

 

25.0 

 

25.0 

 

25.0 

 

25.0 

Hyundai 

 

24.5 

 

24.5 

 

24.5 

 

24.5 

 

24.5 

Lotus 

Maserati 

Mercedes 

 

18.7 

 

18.7 

 

18.7 

 

18.7 

 

18.7 

Mitsubishi 

 

24.9 

 

23.8 

 

26.6 

 

26.7 

 

26.7 

Nissan 

 

20.9 

 

21.0 

 

21.0 

 

21.0 

 

21.0 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

22.8 

 

22.8 

 

22.8 

 

22.8 

 

22.8 

Toyota 

 

23.3 

 

23.1 

 

23.4 

 

23.4 

 

23.4 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

22.9 

 

23.1 

 

23.5 

 

23.6 

 

23.7 
VI-14

Table VI-2b 

Adjusted Baseline 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

23.6 

 

23.9 

 

24.5 

 

25.1 

 

25.6 

Ferrari 

Ford 

 

23.6 

 

24.1 

 

25.3 

 

25.3 

 

25.3 

Fuji (Subaru) 

 

27.5 

 

27.5 

 

27.5 

 

27.5 

 

27.5 

General Motors 

 

22.9 

 

23.0 

 

23.0 

 

23.0 

 

23.0 

Honda 

 

25.0 

 

25.0 

 

25.0 

 

25.0 

 

25.0 

Hyundai 

 

25.2 

 

25.2 

 

25.2 

 

25.2 

 

25.2 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

26.7 

 

29.8 

 

29.9 

 

29.9 

Nissan 

 

23.7 

 

24.5 

 

24.5 

 

24.5 

 

24.5 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

28.3 

Toyota 

 

23.4 

 

23.2 

 

23.5 

 

23.5 

 

23.5 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

23.5 

 

23.7 

 

24.2 

 

24.3 

 

24.4 
VI-15

Table VI-2c 

Estimated Achievable Fuel Economy Levels 

25% Below Optimized 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.0 

 

25.6 

 

27.7 

 

27.8 

 

28.0 

Ferrari 

Ford 

 

24.6 

 

25.7 

 

27.7 

 

27.7 

 

27.7 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

32.6 

 

32.8 

General 

Motors 

 

23.0 

 

24.7 

 

26.3 

 

26.3 

 

26.3 

Honda 

 

26.0 

 

27.2 

 

28.6 

 

28.6 

 

28.6 

Hyundai 

 

26.1 

 

28.7 

 

30.0 

 

30.0 

 

30.3 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

33.1 

 

36.9 

 

37.1 

 

37.2 

Nissan 

 

23.8 

 

25.8 

 

27.1 

 

27.1 

 

27.1 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

33.6 

Toyota 

 

24.7 

 

25.6 

 

26.9 

 

26.9 

 

26.9 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.3 

 

25.5 

 

27.3 

 

27.3 

 

27.4 
VI-16

Table VI-2d 

Required Fuel Economy Levels 

Proposed Optimized (7%) Standard 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

28.2 

 

29.9 

 

31.2 

 

31.4 

 

31.7 

Chrysler 

 

25.2 

 

26.6 

 

28.0 

 

28.5 

 

29.1 

Ferrari 

Ford 

 

24.7 

 

26.1 

 

28.0 

 

28.3 

 

28.8 

Fuji (Subaru) 

 

30.0 

 

31.7 

 

33.1 

 

33.2 

 

33.4 

General Motors 

 

23.9 

 

25.4 

 

26.5 

 

27.0 

 

27.4 

Honda 

 

26.1 

 

27.7 

 

28.9 

 

29.2 

 

29.6 

Hyundai 

 

27.5 

 

29.1 

 

30.4 

 

30.6 

 

31.0 

Lotus 

Maserati 

Mercedes 

 

28.4 

 

30.1 

 

31.4 

 

31.6 

 

31.9 

Mitsubishi 

 

29.4 

 

30.8 

 

32.2 

 

32.3 

 

32.6 

Nissan 

 

24.9 

 

26.2 

 

27.3 

 

27.7 

 

28.2 

Porsche 

 

25.9 

 

27.4 

 

28.7 

 

29.0 

 

29.4 

Suzuki 

 

30.3 

 

32.1 

 

33.5 

 

33.5 

 

33.7 

Toyota 

 

24.9 

 

26.0 

 

27.2 

 

27.6 

 

28.0 

Volkswagen 

 

26.2 

 

27.8 

 

29.0 

 

29.3 

 

29.7 

Total/Average 

 

25.0 

 

26.4 

 

27.8 

 

28.2 

 

28.6 
VI-17

Table VI-2e 

Estimated Achievable Fuel Economy Levels 

Proposed Optimized (7%) Standard 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.2 

 

25.7 

 

28.0 

 

28.7 

 

29.1 

Ferrari 

Ford 

 

24.7 

 

26.1 

 

28.0 

 

28.3 

 

28.8 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

33.2 

 

33.5 

General Motors 

 

23.0 

 

24.7 

 

26.5 

 

27.0 

 

27.4 

Honda 

 

26.1 

 

27.7 

 

28.9 

 

29.2 

 

29.6 

Hyundai 

 

26.1 

 

29.1 

 

30.4 

 

30.5 

 

31.0 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

33.1 

 

36.9 

 

37.1 

 

37.2 

Nissan 

 

23.8 

 

26.2 

 

27.6 

 

27.7 

 

28.2 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

24.9 

 

26.0 

 

27.2 

 

27.6 

 

28.0 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.4 

 

25.8 

 

27.5 

 

28.0 

 

28.4 
VI-18

Table VI-2f 

Estimated Achievable Fuel Economy Levels 

25% Above Optimized 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.3 

 

25.8 

 

28.2 

 

29.2 

 

30.3 

Ferrari 

Ford 

 

24.8 

 

26.6 

 

28.2 

 

29.1 

 

29.9 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

35.1 

 

35.1 

General 

Motors 

 

23.0 

 

24.7 

 

26.8 

 

27.4 

 

28.2 

Honda 

 

26.3 

 

29.1 

 

29.1 

 

29.9 

 

30.9 

Hyundai 

 

26.1 

 

30.2 

 

30.7 

 

30.8 

 

32.4 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

32.9 

 

36.6 

 

36.7 

 

36.7 

Nissan 

 

23.8 

 

26.5 

 

27.9 

 

28.1 

 

29.1 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

25.0 

 

26.5 

 

27.4 

 

27.9 

 

29.2 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.4 

 

26.1 

 

27.8 

 

28.5 

 

29.5 
VI-19

Table VI-2g 

Estimated Achievable Fuel Economy Levels 

50% Above Optimized 

Light Trucks 

 (mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.4 

 

25.9 

 

28.6 

 

29.9 

 

30.6 

Ferrari 

Ford 

 

25.0 

 

27.0 

 

28.5 

 

29.7 

 

30.5 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

35.0 

 

36.5 

General 

Motors 

 

23.0 

 

24.7 

 

27.0 

 

27.6 

 

28.4 

Honda 

 

26.3 

 

29.2 

 

29.6 

 

30.7 

 

32.6 

Hyundai 

 

26.1 

 

30.2 

 

31.0 

 

31.1 

 

34.0 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

33.1 

 

36.9 

 

37.1 

 

37.2 

Nissan 

 

23.8 

 

27.1 

 

27.9 

 

28.1 

 

29.2 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

25.3 

 

26.9 

 

27.7 

 

28.1 

 

29.8 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.6 

 

26.3 

 

28.0 

 

28.9 

 

30.0 
VI-20

Table VI-2h 

Estimated Achievable Fuel Economy Levels 

 Optimized (3%) 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.2 

 

25.7 

 

28.2 

 

28.9 

 

29.5 

Ferrari 

Ford 

 

24.7 

 

26.1 

 

28.2 

 

28.7 

 

29.2 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

33.6 

 

33.9 

General 

Motors 

 

23.0 

 

24.7 

 

26.7 

 

27.2 

 

27.7 

Honda 

 

26.2 

 

27.7 

 

29.1 

 

29.6 

 

30.1 

Hyundai 

 

26.1 

 

29.2 

 

30.3 

 

30.4 

 

31.7 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

33.1 

 

36.9 

 

37.1 

 

37.2 

Nissan 

 

23.8 

 

26.2 

 

27.6 

 

27.7 

 

28.7 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

24.9 

 

26.0 

 

27.5 

 

27.9 

 

28.5 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.4 

 

25.8 

 

27.7 

 

28.2 

 

28.8 
VI-21

Table VI-2i 

Estimated Achievable Fuel Economy Levels 

 Total Cost = Total Benefit 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.8 

 

26.2 

 

29.1 

 

30.8 

 

31.0 

Ferrari 

Ford 

 

25.1 

 

27.6 

 

29.0 

 

30.4 

 

31.0 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

36.1 

 

40.9 

General 

Motors 

 

23.0 

 

24.7 

 

27.1 

 

27.7 

 

28.5 

Honda 

 

26.3 

 

30.0 

 

30.0 

 

32.1 

 

34.5 

Hyundai 

 

26.1 

 

30.3 

 

31.5 

 

31.6 

 

34.6 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

34.4 

 

38.5 

 

38.6 

 

38.7 

Nissan 

 

23.8 

 

27.4 

 

28.9 

 

29.1 

 

30.2 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

25.4 

 

26.9 

 

28.2 

 

28.7 

 

30.0 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.7 

 

26.5 

 

28.5 

 

29.5 

 

30.5 
VI-22

Table VI-2j 

Estimated Achievable Fuel Economy Levels 

 Technology Exhaustion 

Light Trucks 

(mpg) 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

22.4 

 

23.8 

 

23.8 

 

23.8 

 

23.8 

Chrysler 

 

25.8 

 

26.3 

 

29.1 

 

30.8 

 

31.0 

Ferrari 

Ford 

 

25.1 

 

27.6 

 

31.1 

 

31.9 

 

32.6 

Fuji (Subaru) 

 

27.8 

 

29.0 

 

32.7 

 

36.1 

 

40.9 

General 

Motors 

 

23.0 

 

24.7 

 

27.1 

 

27.7 

 

28.5 

Honda 

 

26.3 

 

30.0 

 

32.5 

 

34.7 

 

36.9 

Hyundai 

 

26.1 

 

30.3 

 

31.5 

 

31.6 

 

34.6 

Lotus 

Maserati 

Mercedes 

 

19.1 

 

19.6 

 

23.4 

 

23.4 

 

23.4 

Mitsubishi 

 

25.5 

 

34.4 

 

38.5 

 

38.7 

 

39.0 

Nissan 

 

23.8 

 

27.4 

 

29.1 

 

29.3 

 

30.4 

Porsche 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

 

17.3 

Suzuki 

 

23.4 

 

23.7 

 

26.4 

 

26.6 

 

34.8 

Toyota 

 

25.4 

 

26.9 

 

31.1 

 

31.4 

 

32.5 

Volkswagen 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

 

20.1 

Total/Average 

 

24.7 

 

26.6 

 

29.4 

 

30.3 

 

31.3 
VI-23
VII-1

VII. COST IMPACTS 

Technology Costs 

Table V-1 provides the technology cost estimates used in this analysis. These are meant to 

represent consumer costs for high-volume production of these technologies after sufficient 

experience with their application have resulted in all “learning curve” effects being fully 

realized. The method taken to get to this consumer cost estimate starts with an initial estimate of 

the incremental manufacturers’ direct costs (or variable costs) for high-volume production of 

these technologies. In the case of some very new technologies, the agency may have only had 

cost estimates from low volume products and has assumed that the products have not matured in 

the development production cycle and that a “learning curve” will result in a reduction in the 

variable cost of the product by 20 percent. The technologies to which the learning curve factors 

were applied are shown in Table V-3. The variable costs are marked up by a factor of 1.5 to take 

into account fixed costs of R&D, burden, manufacturer’s profits, and dealer’s profits. The final 

results are shown in Table V-1. 

The variable costs are incremental costs in material, labor, and variable burden for the product. 

For example, if a vehicle already has a 4-speed automatic transmission, the cost of applying a 5-

speed transmission is assumed to be the incremental cost, calculated as the cost of applying a 5-

speed transmission less the cost of applying the previously applied 4-speed automatic 

transmission. 

The learning curve

For some of the technologies, we have included a learning factor. The “learning curve” 

describes the reduction in unit production costs as a function of accumulated production volume 

and small redesigns that reduce costs. 

A typical learning curve can be described by three parameters: (1) the initial production volume 

before cost reductions begin to be realized; (2) the rate at which cost reductions occur with 

increases in cumulative production beyond this initial volume (usually referred to as the 

“learning rate”); and (3) the production volume after which costs reach a “floor,” and further cost 

reductions no longer occur. Over the region where costs decline with accumulating production 

volume, an experience curve can be expressed as C(Q) = aQ-b, where a is a constant coefficient, 

Q represents cumulative production, and b is a coefficient corresponding to the assumed learning 

rate. In turn, the learning rate L, which is usually expressed as the percent by which average 

unit cost declines with a doubling of cumulative production, and is related to the value of the 

coefficient b by L = 100*(1 – 2-b)

136.

Figure VII-1 illustrates a learning curve for a vehicle technology with an initial average unit cost 

of $100 and a learning rate of approximately 20 percent. In this hypothetical example, the initial 

 

136 See, for example, Robert H. Williams, “Toward Cost Buydown via Learning-by-Doing for Environmental 

Energy Technologies,” paper presented at Workshop on Learning-by-Doing in Energy Technologies, Resources for 

the Future, Washington, D.C., June 17-18, 2003, pp. 1-2. Another common but equivalent formulation of the 

relationship between L and b is (1-L)=2-b, where (1-L) is referred to as the progress ratio; see Richard P. Rumelt, 

“Note on Strategic Cost Dynamics,” POL 2001-1.1, Anderson School of Business, University of California, Los 

Angeles, California, 2001, pp. 4-5. 
VII-2

production volume before cost reductions begin to be realized is set at 12,000 units and the 

production volume at the cost floor is set at roughly 50,000 units. 

$-

$20

$40

$60

$80

$100

$120

0 20000 40000 60000 80000 100000 120000 140000

Cumulative Volume

Cost

Figure VII-1 Typical Experience Curve 

 

Most studies of the effect of the learning curve on production costs appear to assume that cost 

reductions begin only after some initial volume threshold has been reached, but not all of these 

studies specify the threshold volume. The rate at which costs decline beyond the initial threshold 

is usually expressed as the percent reduction in average unit cost that results from each 

successive doubling of cumulative production volume, sometimes referred to as the learning rate. 

Many estimates of learning experience curves do not specify a cumulative production volume 

beyond which cost reductions no longer occur, instead depending on the asymptotic behavior of 

the above expression of (CQ) for learning rates below 100 percent to establish a floor on costs. 
VII-3

Table VII-1 summarizes estimates of learning rates derived from studies of production costs for 

various products.137 

Table VII-1 

Estimated Learning Rates and Associated Volumes for Various Products 

Product(s) Costs Affected Threshold Volume Learning Rate

Photovoltaic cells Total costs Not reported 20% 

Wind turbines Total costs 100 MW 20% 

Gas turbines Total costs 100 MW 10% 

Semiconductors Total costs Not reported 13-24% 

Automobile assembly Assembly labor Not reported 16% 

Truck manufacturing Total costs Not reported 10% 

Battery-electric LDV Total costs 10,000 units 10% 

Fuel cell hybrid LDV Total costs 10,000 units 16% 

Fuel cell LDV powertrain Total costs 10,000 units 19% 

In past rulemaking analyses, EPA has used a learning curve factor of 20 percent for each 

doubling of production volume. For this analysis, however, NHTSA has applied learning curve 

cost reductions on a manufacturer-specific basis, and have assumed that learning-based 

reductions in technology costs occur once during the time that a manufacturer applies the given 

technology to 25,000 cars or trucks, and are repeated a second time as it produces another 25,000 

cars or trucks for the second learning step (car and truck volumes are treated separately for 

determining these sales volumes). The volumes chosen represent our best estimate for where 

learning would occur. As such, NHTSA believes that these estimates are better suited to this 

analysis than the more general approach used by EPA in past rules, because each manufacturer 

would be implementing technologies at its own pace in this rule, rather than assuming that all 

manufacturers implement each identical technology at the same time. The volumes chosen 

represent our best estimate for where learning would occur. 

For this analysis, the agency has used engineering judgment to estimate the development 

production cycle and maturity level for each technology. After having produced 25,000 cars or 

trucks with a specific part or system, we believe that sufficient learning will have taken place 

such that costs will be lower by 20 percent for some technologies and 10 percent for others. 

After another 25,000 units for some technologies, another cost reduction will have been realized. 

When we applied a learning curve, we applied a 20 percent learning factor for all newly applied 

technologies except for diesel engines. We have applied a 10 percent factor for diesel costs here 

because we believe that the diesel technologies being considered are reaching their “learned” 

limit and, therefore, less learning reductions are available.138

 

137 Adapted from Williams, Figure 1, p. 14; Rumelt, Exhibit 5, p. 5; Linda Argote and Dennis Epple, “Learning 

Curves in Manufacturing,” Science, Vol. 247 (1990), pp. 920-924; and Philip Auerswald et al., “The Production 

Recipes Approach to Modeling Technological Innovation: An Application to Learning by Doing,” Journal of 

Economic Dynamics and Control, Vol. 24 (2000), pp. 389-450. 

138 Importantly, diesel technologies can still be considered to have some learning left given recent announcements by 

General Motors stating potential cost savings associated with their new 4.5 liter Duramax diesel V8 engine (see 

Automotive News, September 24, 2007). 
VII-4

For each of the technologies, we have considered whether we could project future cost 

reductions due to manufacturer learning. In making this determination, we considered whether 

or not the technology was in wide-spread use today or expected to be by the model year 2011 

time frame, in which case no future learning curve would apply because the technology is 

already in wide-spread production by the automotive industry today, e.g., on the order of multimillions of units per year. (Examples of these include 5-speed automatic transmissions and 

intake-cam phasing variable valve timing. These technologies have been in production for lightduty vehicles for more than 10 years.) In addition, we carefully considered the underlying 

source data for our cost estimate. If the source data specifically stated that manufacturer cost 

reduction from future learning would occur, we took that information into account in 

determining whether we would apply manufacturer learning in our cost projections. Thus, for 

many of the technologies, we have not applied any future cost reduction learning curve. 

However, there are a number of technologies which are not yet in mass production for which we 

have estimated the initial cost will be reduced in the time frame of this rule due to manufacturer 

production learning. As indicated in Table V-3, we have applied the learning curve beginning in 

2011 to one set of technologies, and for a number of additional technologies we did not apply 

manufacturer learning until 2014. The distinction between 2011 and 2014 is due to our source 

data for our cost estimates. For those technologies where we have applied manufacturer learning 

in 2011, the source of our cost estimate did not rely on manufacturer learning to develop the 

initial cost estimate we have used – therefore we apply the manufacturer learning methodology 

beginning in 2011. 

The technologies for which we do not begin applying learning until 2014 all have the same 

reference source, the 2004 NESCCAF study, for which the sub-contractor was The Martec 

Group. In the work done for the 2004 NESCCAF report, Martec relied upon actual price quotes 

from Tier 1 automotive suppliers to develop automotive manufacturer cost estimates. Based on 

information presented by Martec to the National Academy of Sciences (NAS) Committee during 

their January 24, 2008 public meeting in Dearborn, Michigan[1], the agency understands that the 

Martec cost estimates done for the NESCCAF report incorporated some element of manufacturer 

learning. Martec informed stated that the Tier 1 suppliers were specifically requested to provide 

price quotes which would be valid for three years (2009-2011), and that for some components 

the Tier 1 supplier included cost reductions in years two and three which the supplier anticipated 

could occur, and which they anticipated would be necessary in order for their quote to be 

competitive with other suppliers. Therefore, for this analysis, we did not apply any learning 

curve to any of the Martec-sourced costs for the first three years of this proposal (2011-2013). 

However, the theory of manufacturer learning is that it is a continuous process, though the rate of 

improvement decreases as the number of units produced increases. While we were not able to 

gain access to the detailed submissions from Tier 1 suppliers which Martec relied upon for their 

estimates, we do believe that additional cost reductions will occur in the future for a number of 

the technologies for which we relied upon the Martec cost estimates for the reasons stated above 

in reference to the general learning curve effect. For those technologies we applied a learning 

 

[1] “Variable Costs of Fuel Economy Technologies” Martec Group, Inc Report Presented to: Committee to Assess 

Technologies for Improving Light-Duty Vehicle Fuel Economy. Division on Engineering and Physical Systems, 

Board on Energy and Environmental Systems, the National Academy of Sciences, January 24, 2008. 
VII-5

curve beginning in 2014. Martec has recently submitted a study to the NAS Committee 

comparing the 2004 NESCAF study with new updated cost information. Given that this study 

had just been completely, the agency could not take it into consideration for the NPRM. 

However, the agency will review the new study and consider its findings in time for the final 

rule. 

Manufacturers’ actual costs for applying these technologies to specific vehicle models are likely 

to include significant additional outlays for accompanying design or engineering changes to each 

model, development and testing of prototype versions, recalibrating engine operating parameters, 

and integrating the technology with other attributes of the vehicle. Manufacturers may also incur 

additional corporate overhead, marketing, or distribution and selling expenses as a consequence 

of their efforts to improve the fuel economy of individual vehicle models and their overall 

product lines. 

In order to account for these additional costs, the agency applies an indirect cost multiplier of 1.5 

to its estimate of the vehicle manufacturers’ direct costs for producing or acquiring each fuel 

economy-improving technology to arrive at a consumer cost. This estimate was developed by 

Argonne National Laboratory in a recent review of vehicle manufacturers’ indirect costs. The 

Argonne study was specifically intended to improve the accuracy of future cost estimates for 

production of vehicles that achieve high fuel economy by employing many of the same advanced 

technologies considered in the agency’s analysis.139 Thus, its recommendation that a multiplier 

of 1.5 be applied to direct manufacturing costs to reflect manufacturers’ increased indirect costs 

for deploying advanced fuel economy technologies appears to be appropriate for use in the 

agency’s current analysis. Historically, NHTSA has used almost the exact same multiplier, a 

multiplier of 1.51, as the markup from variable costs or direct manufacturing costs to consumer 

costs. This markup takes into account fixed costs, burden, manufacturer’s profit, and dealers 

profit. NHTSA’s methodology for developing this markup factor was recently peer reviewed 

(see Docket No.27453-4). 

Potential opportunity costs of improved fuel economy 

An important concern is whether achieving the fuel economy improvements required by 

alternative CAFE standards would require manufacturers to compromise the performance, 

carrying capacity, safety, or comfort of their vehicles. If it did so, the resulting sacrifice in the 

value of these attributes to vehicle buyers would represent an additional cost of achieving the 

required improvements in fuel economy, and thus of manufacturers’ compliance with stricter 

CAFE standards. While exact dollar values of these attributes to buyers are extremely difficult 

to infer from vehicle purchase prices, it is nevertheless clear that changes in these attributes can 

affect the utility that vehicle provide to their owners, and thus their value to potential buyers. 

The agency has approached this potential problem by developing cost estimates for fuel 

economy-improving technologies that include any additional manufacturing costs that would be 

necessary to maintain the performance, comfort, capacity, or safety of any vehicle to which those 

technologies are applied. In doing so, the agency followed the precedent established by NAS in 

 

139 Vyas, Anant, Dan Santini, and Roy Cuenca, Comparison of Indirect Cost Multipliers for Vehicle 

Manufacturing, Center for Transportation Research, Argonne National Laboratory, April 2000. 
VII-6

its 2002 analysis of the costs and benefits of improving fuel economy by raising CAFE 

standards.140 The NAS study estimated “constant performance and utility” costs for fuel 

economy technologies, and the agency has used these as the basis for developing the technology 

costs it employed in analyzing manufacturer’s costs for complying with alternative standards. 

NHTSA fully acknowledges the difficulty of estimating technology costs that include costs for 

the accompanying changes in vehicle design that are necessary to maintain performance, 

capacity, and utility. However, the agency believes its cost estimates for fuel economy 

technologies are generally sufficient to prevent significant reductions in consumer welfare. 

The technology application algorithm implemented with the Volpe model was used as the basis 

for estimating costs for the fleet. We applied the technology application algorithm described in 

Chapter VI. 

 

The agency did estimate the costs or fines to bring passenger car manufacturers up to the 27.5 

mpg level in place for MY 2010 as shown in Table VII-2. Table VII-3 shows the estimates for 

those light truck manufacturers that are not planning on meeting the CAFE reform level for MY 

2011, without using fuel economy adjustments for alternative fueled vehicles, up to the level 

required for them for MY 2011. These costs have been estimated, but they are not considered to 

be part of the costs of meeting the proposed requirements. Those costs, and commensurate 

benefits, are considered part of the costs and benefits of complying with previously issued rules. 

Tables VII-4a through 4n for passenger cars and Tables VII-5a through 5n show the costs for 

light trucks (on an average cost-per-vehicle basis and on a total cost basis) of applying 

technology necessary to move each manufacturer’s planned fuel economy levels up to the level 

of the alternative. Thus, if a manufacturer’s product plans resulted in a fuel economy level of 

22.2 mpg during each model year, the cost represents the cumulative cost of technologies 

necessary to bring that manufacturer’s fleet average up to the levels of the alternative. The costs 

for several manufacturers are the fines that these manufacturers would have to pay on an average 

vehicle basis. We assume that the costs of fines will be passed on to consumers. The second 

part of each of these tables shows the estimated total manufacturer costs in millions of dollars. 

Fines are not included in the second part of these tables, since these are transfer payments and 

not technology costs. 

 

140 National Academy of Sciences, Costs and Effectiveness of Increasing Corporate Average Fuel Economy 

Standards, 2002. 
VII-7

Table VII-2 

Estimated Incremental Costs or Fines over Manufacturer’s Plans 

To get to Adjusted Baseline - Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW 

 

58 

 

59 

 

60 

 

61 

 

61 

Chrysler 

 

- 

 

- 

 

- 

 

- 

 

- 

Ferrari 

 

710 

 

710 

 

710 

 

710 

 

710 

Ford 

 

- 

 

- 

 

- 

 

- 

 

- 

Fuji (Subaru) 

 

39 

 

40 

 

40 

 

41 

 

41 

General Motors 

 

- 

 

- 

 

- 

 

- 

 

- 

Honda 

 

- 

 

- 

 

- 

 

- 

 

- 

Hyundai 

 

- 

 

- 

 

- 

 

- 

 

- 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

638 

 

638 

 

638 

 

638 

 

638 

Mercedes 

 

255 

 

323 

 

328 

 

356 

 

359 

Mitsubishi 

 

- 

 

- 

 

- 

 

- 

 

- 

Nissan 

 

- 

 

- 

 

- 

 

- 

 

- 

Porsche 

 

334 

 

353 

 

355 

 

454 

 

458) 

Suzuki 

 

- 

 

- 

 

- 

 

- 

 

- 

Toyota 

 

- 

 

- 

 

- 

 

- 

 

- 

Volkswagen 

 

- 

 

- 

 

- 

 

- 

 

- 

Total/Average 

 

11 

 

13 

 

13 

 

14 

 

14 
VII-8

Table VII-3 

Estimated Incremental Costs or Fines over Manufacturer’s Plans 

To get to Adjusted Baseline - Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW 

 

499 

 

761 

 

745 

 

727 

 

720 

Chrysler 

 

9 

 

9 

 

9 

 

9 

 

9 

Ferrari 

Ford 

 

- 

 

- 

 

- 

 

- 

 

- 

Fuji (Subaru) 

 

35 

 

34 

 

33 

 

32 

 

32 

General Motors 

 

647 

 

645 

 

630 

 

612 

 

606 

Honda 

 

- 

 

- 

 

- 

 

- 

 

- 

Hyundai 

 

106 

 

103 

 

101 

 

98 

 

97 

Lotus 

Maserati 

Mercedes 

 

433 

 

586 

 

1,152 

 

1,124 

 

1,113 

Mitsubishi 

 

153 

 

444 

 

419 

 

408 

 

403 

Nissan 

 

1,105 

 

1,181 

 

1,147 

 

1,111 

 

1,097 

Porsche 

 

363 

 

363 

 

363 

 

363 

 

363 

Suzuki 

 

321 

 

377 

 

1,081 

 

1,070 

 

1,101 

Toyota 

 

6 

 

5 

 

5 

 

5 

 

5 

Volkswagen 

 

220 

 

220 

 

220 

 

220 

 

220 

Total/Average 

 

240 

 

244 

 

248 

 

241 

 

239 
VII-9

Table VII-4a 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Below Optimized 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

456 

 

513 

 

611 

 

710 

 

781 

Chrysler 

 

- 

 

- 

 

- 

 

- 

 

109 

Ferrari 

 

77 

 

116 

 

193 

 

248 

 

314 

Ford 

 

439 

 

240 

 

239 

 

312 

 

411 

Fuji (Subaru) 

 

509 

 

537 

 

912 

 

2,825 

 

3,764 

General 

Motors 

 

42 

 

150 

 

323 

 

453 

 

750 

Honda 

 

- 

 

- 

 

- 

 

- 

 

- 

Hyundai 

 

- 

 

- 

 

45 

 

92 

 

173 

Lotus 

 

363 

 

391 

 

462 

 

506 

 

556 

Maserati 

 

6 

 

50 

 

127 

 

193 

 

264 

Mercedes 

 

138 

 

176 

 

253 

 

439 

 

528 

Mitsubishi 

 

109 

 

159 

 

290 

 

533 

 

1,127 

Nissan 

 

- 

 

- 

 

24 

 

116 

 

219 

Porsche 

 

435 

 

457 

 

528 

 

578 

 

627 

Suzuki 

 

416 

 

615 

 

697 

 

2,087 

 

2,160 

Toyota 

 

- 

 

- 

 

- 

 

- 

 

- 

Volkswagen 

 

299 

 

332 

 

440 

 

489 

 

614 

Total/Average 

 

126 

 

126 

 

187 

 

294 

 

428 
VII-10

Table VII-4b 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Below Optimized 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

- 

 

- 

 

- 

 

- 

 

61.2 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

570.2 

 

307.9 

 

304.6 

 

390.5 

 

509.1 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

75.9 

 

270.7 

 

548.2 

 

795.4 

 

1,305.7 

Honda 

 

- 

 

- 

 

- 

 

- 

 

- 

Hyundai 

 

- 

 

- 

 

23.6 

 

47.2 

 

88.0 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

12.5 

 

18.0 

 

32.7 

 

58.9 

 

122.7 

Nissan 

 

- 

 

- 

 

16.4 

 

79.1 

 

147.6 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

162.9 

Toyota 

 

- 

 

- 

 

- 

 

- 

 

- 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

834.8 

 

818.4 

 

1,253.3 

 

2,152.6 

 

3,208.7 
VII-11

Table VII-4c 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Proposed Optimized (7%) 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

555 

 

672 

 

748 

 

831 

 

891 

Chrysler 

 

29 

 

135 

 

151 

 

228 

 

401 

Ferrari 

 

160 

 

248 

 

308 

 

352 

 

407 

Ford 

 

782 

 

560 

 

627 

 

691 

 

790 

Fuji (Subaru) 

 

630 

 

730 

 

1,077 

 

2,968 

 

3,890 

General Motors 

 

338 

 

535 

 

644 

 

767 

 

988 

Honda 

 

- 

 

- 

 

- 

 

23 

 

55 

Hyundai 

 

21 

 

175 

 

390 

 

442 

 

530 

Lotus 

 

490 

 

594 

 

638 

 

660 

 

688 

Maserati 

 

77 

 

171 

 

237 

 

292 

 

358 

Mercedes 

 

231 

 

319 

 

380 

 

554 

 

627 

Mitsubishi 

 

1,113 

 

1,585 

 

1,589 

 

1,850 

 

2,303 

Nissan 

 

37 

 

164 

 

259 

 

331 

 

575 

Porsche 

 

556 

 

655 

 

704 

 

726 

 

759 

Suzuki 

 

537 

 

813 

 

868 

 

2,236 

 

2,521 

Toyota 

 

- 

 

- 

 

- 

 

- 

 

5 

Volkswagen 

 

409 

 

508 

 

594 

 

627 

 

735 

Total/Average 

 

276 

 

334 

 

404 

 

512 

 

649 
VII-12

Table VII-4d 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Proposed Optimized (7%) 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

16.8 

 

78.5 

 

87.1 

 

129.0 

 

209.1 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

719.3 

 

798.5 

 

863.9 

 

978.9 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General Motors 

 

617.6 

 

965.9 

 

1,103.2 

 

1,346.4 

 

1,720.2 

Honda 

 

- 

 

- 

 

- 

 

20.5 

 

48.6 

Hyundai 

 

11.2 

 

92.5 

 

204.1 

 

226.8 

 

258.3 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

127.7 

 

179.9 

 

178.9 

 

204.3 

 

252.1 

Nissan 

 

26.1 

 

114.9 

 

179.6 

 

225.2 

 

387.6 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

190.1 

Toyota 

 

- 

 

- 

 

- 

 

- 

 

5.9 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

1,884.4 

 

2,372.6 

 

2,879.1 

 

3,797.5 

 

4,862.2 
VII-13

Table VII-4e 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Above Optimized 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

654 

 

832 

 

886 

 

958 

 

1,001 

Chrysler 

 

328 

 

462 

 

738 

 

849 

 

753 

Ferrari 

 

248 

 

380 

 

418 

 

462 

 

501 

Ford 

 

870 

 

942 

 

1,103 

 

1,492 

 

1,539 

Fuji (Subaru) 

 

751 

 

922 

 

1,242 

 

3,122 

 

4,022 

General 

Motors 

 

814 

 

1,510 

 

1,594 

 

1,913 

 

2,028 

Honda 

 

- 

 

115 

 

148 

 

193 

 

357 

Hyundai 

 

245 

 

513 

 

673 

 

704 

 

742 

Lotus 

 

622 

 

798 

 

814 

 

820 

 

825 

Maserati 

 

154 

 

286 

 

336 

 

391 

 

446 

Mercedes 

 

319 

 

462 

 

501 

 

670 

 

732 

Mitsubishi 

 

2,091 

 

3,326 

 

3,307 

 

3,633 

 

3,847 

Nissan 

 

520 

 

1,065 

 

1,142 

 

1,195 

 

1,394 

Porsche 

 

682 

 

858 

 

875 

 

886 

 

891 

Suzuki 

 

664 

 

1,011 

 

1,033 

 

2,390 

 

3,945 

Toyota 

 

- 

 

- 

 

7 

 

42 

 

83 

Volkswagen 

 

525 

 

690 

 

743 

 

764 

 

856 

Total/Average 

 

494 

 

778 

 

871 

 

1,078 

 

1,185 
VII-14

Table VII-4f 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Above Optimized 

Total Cost in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

192.2 

 

268.0 

 

424.4 

 

479.1 

 

384.7 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

1,062.3 

 

1,300.5 

 

1,817.6 

 

1,907.6 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

1,374.8 

 

2,606.9 

 

2,734.2 

 

3,359.4 

 

3,530.5 

Honda 

 

- 

 

105.4 

 

133.6 

 

171.3 

 

315.0 

Hyundai 

 

130.7 

 

270.9 

 

351.8 

 

361.5 

 

371.7 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

236.7 

 

373.2 

 

372.1 

 

401.2 

 

418.7 

Nissan 

 

367.3 

 

744.8 

 

791.4 

 

812.9 

 

939.8 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

297.4 

Toyota 

 

- 

 

- 

 

9.4 

 

54.9 

 

107.0 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

3,386.6 

 

5,653.1 

 

6,445.3 

 

8,239.5 

 

9,083.9 
VII-15

Table VII-4g 

Estimated Incremental Costs or Fines over Adjusted Baseline 

50% Above Optimized 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

753 

 

991 

 

1,051 

 

1,117 

 

1,166 

Chrysler 

 

1,045 

 

1,478 

 

1,475 

 

1,442 

 

1,137 

Ferrari 

 

325 

 

512 

 

539 

 

561 

 

594 

Ford 

 

952 

 

1,079 

 

1,230 

 

1,608 

 

2,009 

Fuji (Subaru) 

 

872 

 

1,120 

 

1,468 

 

3,364 

 

4,297 

General 

Motors 

 

891 

 

1,636 

 

1,709 

 

2,152 

 

2,505 

Honda 

 

19 

 

769 

 

880 

 

946 

 

981 

Hyundai 

 

421 

 

1,895 

 

1,916 

 

1,971 

 

2,035 

Lotus 

 

754 

 

1,012 

 

1,062 

 

1,100 

 

1,155 

Maserati 

 

226 

 

407 

 

435 

 

451 

 

484 

Mercedes 

 

407 

 

605 

 

638 

 

791 

 

847 

Mitsubishi 

 

2,184 

 

3,485 

 

4,115 

 

4,466 

 

4,765 

Nissan 

 

753 

 

1,492 

 

2,005 

 

2,343 

 

2,498 

Porsche 

 

814 

 

1,067 

 

1,111 

 

1,150 

 

1,205 

Suzuki 

 

790 

 

1,215 

 

1,269 

 

2,648 

 

5,019 

Toyota 

 

- 

 

115 

 

138 

 

172 

 

223 

Volkswagen 

 

635 

 

871 

 

941 

 

973 

 

1,092 

Total/Average 

 

620 

 

1,133 

 

1,251 

 

1,501 

 

1,694 
VII-16

Table VII-4h 

Estimated Incremental Costs or Fines over Adjusted Baseline 

50% Above Optimized 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

593.5 

 

857.9 

 

848.6 

 

813.9 

 

611.4 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

1,062.3 

 

1,300.5 

 

1,817.6 

 

2,489.5 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

1,374.8 

 

2,606.9 

 

2,734.2 

 

3,634.7 

 

4,313.3 

Honda 

 

17.9 

 

657.7 

 

772.0 

 

840.9 

 

864.4 

Hyundai 

 

224.6 

 

999.7 

 

1,002.0 

 

1,011.6 

 

1,026.8 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

236.7 

 

373.2 

 

461.8 

 

487.1 

 

513.2 

Nissan 

 

478.1 

 

951.1 

 

1,355.5 

 

1,593.9 

 

1,684.4 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

378.4 

Toyota 

 

- 

 

154.4 

 

183.8 

 

225.5 

 

288.5 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

4,010.5 

 

7,884.7 

 

8,986.1 

 

11,206.8 

 

12,981.4 
VII-17

Table VII-4i 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Optimized (3%) 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

923 

 

1,068 

 

1,089 

 

1,200 

 

1,215 

Chrysler 

 

1,182 

 

1,684 

 

1,753 

 

1,982 

 

1,611 

Ferrari 

 

473 

 

589 

 

589 

 

671 

 

677 

Ford 

 

1,095 

 

1,156 

 

1,274 

 

1,707 

 

2,328 

Fuji (Subaru) 

 

1,092 

 

1,225 

 

1,523 

 

3,414 

 

4,308 

General 

Motors 

 

1,028 

 

1,708 

 

1,753 

 

2,256 

 

2,593 

Honda 

 

667 

 

1,198 

 

1,229 

 

1,298 

 

1,336 

Hyundai 

 

1,875 

 

2,287 

 

2,308 

 

2,401 

 

2,429 

Lotus 

 

963 

 

1,095 

 

1,095 

 

1,111 

 

1,122 

Maserati 

 

363 

 

457 

 

468 

 

572 

 

583 

Mercedes 

 

561 

 

682 

 

682 

 

890 

 

924 

Mitsubishi 

 

2,371 

 

3,584 

 

4,176 

 

4,560 

 

4,826 

Nissan 

 

907 

 

1,574 

 

2,054 

 

2,661 

 

2,824 

Porsche 

 

1,018 

 

1,150 

 

1,150 

 

1,172 

 

1,183 

Suzuki 

 

1,010 

 

1,314 

 

1,319 

 

2,687 

 

5,019 

Toyota 

 

78 

 

232 

 

234 

 

350 

 

373 

Volkswagen 

 

844 

 

970 

 

1,001 

 

1,039 

 

1,120 

Total/Average 

 

896 

 

1,284 

 

1,376 

 

1,706 

 

1,915 
VII-18

Table VII-4j 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Optimized 3% 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

593.5 

 

977.3 

 

1,008.6 

 

1,116.0 

 

861.3 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

1,062.3 

 

1,300.5 

 

1,817.6 

 

2,831.4 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

1,374.8 

 

2,606.9 

 

2,734.2 

 

3,634.7 

 

4,313.3 

Honda 

 

616.0 

 

1,079.8 

 

1,113.3 

 

1,154.4 

 

1,177.7 

Hyundai 

 

976.4 

 

1,206.9 

 

1,206.9 

 

1,232.4 

 

1,235.9 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

236.7 

 

373.2 

 

461.8 

 

487.1 

 

513.2 

Nissan 

 

478.1 

 

951.1 

 

1,355.5 

 

1,765.4 

 

1,878.4 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

378.4 

Toyota 

 

106.3 

 

312.3 

 

312.2 

 

458.0 

 

483.4 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

5,466.7 

 

8,791.5 

 

9,820.9 

 

12,447.1 

 

14,484.5 
VII-19

Table VII-4k 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Total Cost = Total Benefit 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

956 

 

1,310 

 

1,331 

 

1,381 

 

1,402 

Chrysler 

 

1,204 

 

2,062 

 

2,734 

 

2,766 

 

2,299 

Ferrari 

 

490 

 

765 

 

765 

 

776 

 

781 

Ford 

 

1,123 

 

1,349 

 

1,466 

 

1,828 

 

2,449 

Fuji (Subaru) 

 

1,136 

 

1,538 

 

1,836 

 

3,711 

 

4,611 

General 

Motors 

 

1,050 

 

1,889 

 

1,935 

 

2,355 

 

2,692 

Honda 

 

978 

 

1,548 

 

1,594 

 

2,071 

 

2,115 

Hyundai 

 

1,891 

 

3,371 

 

3,529 

 

4,003 

 

4,039 

Lotus 

 

1,040 

 

1,463 

 

1,463 

 

1,480 

 

1,496 

Maserati 

 

385 

 

633 

 

649 

 

660 

 

666 

Mercedes 

 

583 

 

886 

 

886 

 

1,022 

 

1,056 

Mitsubishi 

 

2,382 

 

3,804 

 

4,396 

 

4,741 

 

5,013 

Nissan 

 

929 

 

1,772 

 

2,252 

 

2,793 

 

2,961 

Porsche 

 

1,089 

 

1,502 

 

1,502 

 

1,518 

 

1,529 

Suzuki 

 

1,060 

 

1,644 

 

1,649 

 

3,006 

 

6,030 

Toyota 

 

195 

 

1,143 

 

1,152 

 

1,174 

 

1,187 

Volkswagen 

 

871 

 

1,245 

 

1,276 

 

1,287 

 

1,373 

Total/Average 

 

966 

 

1,685 

 

1,829 

 

2,159 

 

2,367 
VII-20

Table VII-4l 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Total Cost = Total Benefit 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

593.5 

 

1,113.5 

 

1,515.9 

 

1,527.5 

 

1,200.0 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

1,062.3 

 

1,300.5 

 

1,817.6 

 

2,831.4 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

1,374.8 

 

2,606.9 

 

2,734.2 

 

3,634.7 

 

4,313.3 

Honda 

 

903.8 

 

1,224.0 

 

1,274.4 

 

1,797.9 

 

1,815.9 

Hyundai 

 

976.4 

 

1,706.0 

 

1,796.7 

 

2,054.8 

 

2,054.8 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

236.7 

 

373.2 

 

461.8 

 

487.1 

 

513.2 

Nissan 

 

478.1 

 

951.1 

 

1,355.5 

 

1,765.4 

 

1,878.4 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

440.9 

Toyota 

 

265.1 

 

1,537.1 

 

1,535.9 

 

1,535.9 

 

1,538.2 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

5,913.2 

 

10,795.8 

 

12,302.7 

 

15,402.5 

 

17,397.6 
VII-21

Table VII-4m 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Technology Exhaustion 

Average Cost per Vehicle (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

1,017 

 

1,475 

 

1,683 

 

1,788 

 

1,969 

Chrysler 

 

1,254 

 

2,155 

 

3,026 

 

3,102 

 

2,739 

Ferrari 

 

556 

 

919 

 

1,084 

 

1,155 

 

1,287 

Ford 

 

1,172 

 

1,503 

 

1,791 

 

2,213 

 

2,961 

Fuji (Subaru) 

 

1,213 

 

1,758 

 

2,260 

 

4,156 

 

5,265 

General 

Motors 

 

1,105 

 

2,027 

 

2,243 

 

2,735 

 

3,187 

Honda 

 

1,180 

 

1,855 

 

2,083 

 

2,605 

 

2,788 

Hyundai 

 

1,968 

 

3,558 

 

3,892 

 

4,728 

 

4,934 

Lotus 

 

1,089 

 

1,661 

 

1,870 

 

1,892 

 

2,134 

Maserati 

 

435 

 

743 

 

919 

 

1,012 

 

1,133 

Mercedes 

 

644 

 

1,045 

 

1,227 

 

1,423 

 

1,595 

Mitsubishi 

 

2,470 

 

4,008 

 

4,770 

 

5,165 

 

5,607 

Nissan 

 

990 

 

1,932 

 

2,582 

 

3,183 

 

3,484 

Porsche 

 

1,139 

 

1,700 

 

1,903 

 

1,936 

 

2,167 

Suzuki 

 

1,131 

 

1,864 

 

2,072 

 

3,446 

 

6,684 

Toyota 

 

239 

 

2,408 

 

2,913 

 

3,487 

 

3,825 

Volkswagen 

 

948 

 

1,449 

 

1,678 

 

1,721 

 

1,994 

Total/Average 

 

1,038 

 

2,032 

 

2,406 

 

2,889 

 

3,264 
VII-22

Table VII-4n 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Technology Exhaustion 

Total Incremental Costs in Millions (2006$) 

Passenger Cars 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

104.6 

 

117.3 

 

134.8 

 

154.4 

 

156.3 

Chrysler 

 

593.5 

 

1,113.5 

 

1,515.9 

 

1,527.5 

 

1,200.0 

Ferrari 

 

- 

 

- 

 

- 

 

- 

 

- 

Ford 

 

908.5 

 

1,062.3 

 

1,300.5 

 

1,817.6 

 

2,831.4 

Fuji (Subaru) 

 

23.1 

 

23.8 

 

70.5 

 

339.2 

 

472.6 

General 

Motors 

 

1,374.8 

 

2,606.9 

 

2,734.2 

 

3,634.7 

 

4,313.3 

Honda 

 

1,069.9 

 

1,389.2 

 

1,444.0 

 

1,964.1 

 

1,982.1 

Hyundai 

 

976.4 

 

1,706.0 

 

1,796.7 

 

2,263.1 

 

2,266.7 

Lotus 

 

- 

 

- 

 

- 

 

- 

 

- 

Maserati 

 

- 

 

- 

 

- 

 

- 

 

- 

Mercedes 

 

- 

 

- 

 

- 

 

52.1 

 

59.8 

Mitsubishi 

 

236.7 

 

373.2 

 

461.8 

 

487.1 

 

513.2 

Nissan 

 

478.1 

 

951.1 

 

1,355.5 

 

1,765.4 

 

1,878.4 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

16.4 

 

44.7 

 

44.7 

 

157.5 

 

440.9 

Toyota 

 

265.1 

 

3,171.3 

 

3,764.8 

 

4,517.6 

 

4,872.6 

Volkswagen 

 

32.2 

 

36.1 

 

77.8 

 

78.3 

 

122.7 

Total/Average 

 

6,079.4 

 

12,595.2 

 

14,701.1 

 

18,758.8 

 

21,110.1 
VII-23
VII-24

Table VII-5a 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Below Optimized 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW 149 220 303 297 303 

Chrysler 251 396 682 599 563 

Ferrari 

Ford 147 218 281 273 270 

Fuji (Subaru) 160 618 2,088 2,031 2,016 

General Motors 113 1,030 1,205 1,173 1,160 

Honda 141 271 492 478 473 

Hyundai 664 898 1,101 1,066 1,067 

Lotus 

Maserati 

Mercedes 149 220 303 297 303 

Mitsubishi 149 2,838 2,630 2,558 2,530 

Nissan 177 340 1,049 1,016 1,003 

Porsche 99 171 248 242 248 

Suzuki 121 198 286 281 2,877 

Toyota 202 367 477 464 459 

Volkswagen 110 182 253 253 253 

Total/Average 185 526 738 705 708 
VII-25

Table VII-5b 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Below Optimized 

Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 417 618 1,193 1,077 1,023 

Ferrari 

Ford 230 351 463 463 463 

Fuji (Subaru) 5 54 232 232 232 

General 

Motors 140 2,124 2,589 2,589 2,589 

Honda 103 204 379 379 379 

Hyundai 157 243 304 304 308 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 107 101 101 101 

Nissan 57 149 474 474 474 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 163 

Toyota 239 447 594 594 594 

Volkswagen 0 0 0 0 0 

Total/Average 1,349 4,296 6,329 6,212 6,326 
VII-26
VII-27

Table VII-5c 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Proposed Optimized (7%) 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

154 

 

248 

 

319 

 

330 

 

347 

Chrysler 

 

329 

 

439 

 

905 

 

838 

 

815 

Ferrari 

Ford 

 

195 

 

288 

 

332 

 

365 

 

425 

Fuji (Subaru) 

 

171 

 

646 

 

2,110 

 

2,061 

 

2,108 

General Motors 

 

118 

 

1,052 

 

1,276 

 

1,453 

 

1,487 

Honda 

 

175 

 

512 

 

668 

 

700 

 

769 

Hyundai 

 

675 

 

1,082 

 

1,243 

 

1,270 

 

1,293 

Lotus 

Maserati 

Mercedes 

 

154 

 

248 

 

319 

 

330 

 

347 

Mitsubishi 

 

160 

 

2,838 

 

2,630 

 

2,558 

 

2,530 

Nissan 

 

182 

 

596 

 

1,283 

 

1,251 

 

1,307 

Porsche 

 

110 

 

193 

 

264 

 

281 

 

303 

Suzuki 

 

132 

 

231 

 

308 

 

308 

 

3,977 

Toyota 

 

262 

 

522 

 

603 

 

774 

 

815 

Volkswagen 

 

116 

 

204 

 

270 

 

286 

 

308 

Total/Average 

 

224 

 

617 

 

861 

 

924 

 

979 
VII-28

Table VII-5d 

Proposed Optimized (7%) 

 Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

- 

 

- 

 

- 

 

- 

 

- 

Chrysler 

 

546.1 

 

663.6 

 

1,583.3 

 

1,507.1 

 

1,481.1 

Ferrari 

Ford 

 

305.2 

 

463.5 

 

546.8 

 

618.1 

 

728.7 

Fuji (Subaru) 

 

5.2 

 

53.8 

 

231.5 

 

235.0 

 

242.9 

General Motors 

 

140.4 

 

2,123.6 

 

2,739.4 

 

3,207.7 

 

3,319.3 

Honda 

 

128.2 

 

384.5 

 

514.4 

 

554.3 

 

615.6 

Hyundai 

 

157.4 

 

293.1 

 

344.9 

 

360.9 

 

373.1 

Lotus 

Maserati 

Mercedes 

 

- 

 

- 

 

- 

 

- 

 

- 

Mitsubishi 

 

- 

 

106.8 

 

101.5 

 

101.5 

 

101.5 

Nissan 

 

57.0 

 

261.4 

 

579.5 

 

583.6 

 

617.3 

Porsche 

 

- 

 

- 

 

- 

 

- 

 

- 

Suzuki 

 

- 

 

- 

 

- 

 

- 

 

224.7 

Toyota 

 

309.6 

 

635.3 

 

752.1 

 

991.8 

 

1,056.5 

Volkswagen 

 

- 

 

- 

 

- 

 

- 

 

- 

Total/Average 

 

1,649.3 

 

4,985.5 

 

7,393.6 

 

8,159.9 

 

8,760.6 
VII-29

Table VII-5e 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Above Optimized 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

171 

 

286 

 

336 

 

374 

 

429 

Chrysler 

 

490 

 

610 

 

1,162 

 

1,173 

 

1,541 

Ferrari 

Ford 

 

233 

 

459 

 

451 

 

797 

 

1,079 

Fuji (Subaru) 

 

187 

 

690 

 

2,126 

 

3,316 

 

3,280 

General 

Motors 

 

129 

 

1,080 

 

1,512 

 

1,831 

 

2,125 

Honda 

 

228 

 

1,307 

 

1,275 

 

1,306 

 

1,400 

Hyundai 

 

686 

 

1,750 

 

1,749 

 

1,804 

 

1,927 

Lotus 

Maserati 

Mercedes 

 

171 

 

286 

 

336 

 

374 

 

429 

Mitsubishi 

 

176 

 

3,173 

 

2,880 

 

2,801 

 

2,771 

Nissan 

 

193 

 

882 

 

1,551 

 

1,529 

 

1,995 

Porsche 

 

121 

 

226 

 

275 

 

319 

 

374 

Suzuki 

 

149 

 

275 

 

325 

 

363 

 

4,010 

Toyota 

 

312 

 

1,020 

 

1,028 

 

1,335 

 

1,628 

Volkswagen 

 

127 

 

237 

 

286 

 

330 

 

380 

Total/Average 

 

279 

 

873 

 

1,141 

 

1,352 

 

1,655 
VII-30

Table VII-5f 

Estimated Incremental Costs or Fines over Adjusted Baseline 

25% Above Optimized 

Total Cost in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 813 919 2,032 2,109 2,800 

Ferrari 

Ford 364 739 744 1,351 1,839 

Fuji (Subaru) 5 54 232 378 378 

General 

Motors 140 2,124 3,246 4,018 4,705 

Honda 167 982 982 1,035 1,122 

Hyundai 157 474 485 505 556 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 119 111 111 111 

Nissan 57 382 700 705 937 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 225 

Toyota 369 1,241 1,282 1,690 2,109 

Volkswagen 0 0 0 0 0 

Total/Average 2,072 7,034 9,815 11,903 14,781 
VII-31

Table VII-5g 

Estimated Incremental Costs or Fines over Adjusted Baseline 

50% Above Optimized 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

176 

 

314 

 

358 

 

424 

 

501 

Chrysler 

 

597 

 

731 

 

1,408 

 

1,657 

 

1,932 

Ferrari 

Ford 

 

462 

 

770 

 

639 

 

1,144 

 

1,418 

Fuji (Subaru) 

 

193 

 

723 

 

2,148 

 

2,982 

 

3,376 

General 

Motors 

 

135 

 

1,102 

 

1,875 

 

2,206 

 

2,518 

Honda 

 

257 

 

1,329 

 

1,325 

 

1,506 

 

2,197 

Hyundai 

 

691 

 

1,750 

 

1,784 

 

1,866 

 

2,439 

Lotus 

Maserati 

Mercedes 

 

176 

 

314 

 

358 

 

424 

 

501 

Mitsubishi 

 

182 

 

2,838 

 

2,630 

 

2,558 

 

2,530 

Nissan 

 

199 

 

1,028 

 

1,337 

 

1,355 

 

1,963 

Porsche 

 

127 

 

248 

 

292 

 

358 

 

435 

Suzuki 

 

154 

 

308 

 

352 

 

418 

 

4,092 

Toyota 

 

563 

 

1,279 

 

1,276 

 

1,535 

 

2,033 

Volkswagen 

 

132 

 

259 

 

303 

 

369 

 

446 

Total/Average 

 

385 

 

1,008 

 

1,347 

 

1,644 

 

2,041 
VII-32

Table VII-5h 

Estimated Incremental Costs or Fines over Adjusted Baseline 

50% Above Optimized 

Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 990 1,097 2,463 2,979 3,432 

Ferrari 

Ford 723 1,237 1,053 1,939 2,372 

Fuji (Subaru) 5 54 232 340 389 

General 

Motors 140 2,124 4,026 4,798 5,485 

Honda 184 999 1,021 1,193 1,760 

Hyundai 157 474 495 515 704 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 107 101 101 101 

Nissan 57 451 604 609 896 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 225 

Toyota 666 1,555 1,591 1,911 2,605 

Volkswagen 0 0 0 0 0 

Total/Average 2,922 8,098 11,586 14,386 17,969 
VII-33

Table VII-5i 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Optimized (3%) 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

160 

 

253 

 

336 

 

363 

 

380 

Chrysler 

 

329 

 

439 

 

1,092 

 

1,022 

 

1,095 

Ferrari 

Ford 

 

195 

 

288 

 

344 

 

398 

 

468 

Fuji (Subaru) 

 

176 

 

651 

 

2,121 

 

2,326 

 

2,362 

General 

Motors 

 

124 

 

1,052 

 

1,435 

 

1,609 

 

1,720 

Honda 

 

192 

 

497 

 

711 

 

775 

 

803 

Hyundai 

 

675 

 

1,078 

 

1,249 

 

1,288 

 

1,356 

Lotus 

Maserati 

Mercedes 

 

160 

 

253 

 

336 

 

363 

 

380 

Mitsubishi 

 

165 

 

2,838 

 

2,630 

 

2,558 

 

2,530 

Nissan 

 

182 

 

596 

 

1,283 

 

1,276 

 

1,765 

Porsche 

 

110 

 

198 

 

275 

 

303 

 

325 

Suzuki 

 

138 

 

237 

 

319 

 

336 

 

3,977 

Toyota 

 

262 

 

522 

 

668 

 

837 

 

891 

Volkswagen 

 

121 

 

204 

 

281 

 

308 

 

336 

Total/Average 

 

227 

 

616 

 

955 

 

1,028 

 

1,145 
VII-34

Table VII-5j 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Optimized 3% 

Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 546 664 1,909 1,837 1,991 

Ferrari 

Ford 305 463 567 675 801 

Fuji (Subaru) 5 54 232 265 272 

General 

Motors 140 2,124 3,081 3,552 3,840 

Honda 141 374 548 614 644 

Hyundai 157 292 341 357 391 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 107 101 101 101 

Nissan 57 261 580 585 834 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 225 

Toyota 310 635 832 1,072 1,154 

Volkswagen 0 0 0 0 0 

Total/Average 1,662 4,974 8,190 9,058 10,253 
VII-35

Table VII-5k 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Total Cost = Total Benefit 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

198 

 

369 

 

391 

 

512 

 

649 

Chrysler 

 

857 

 

1,012 

 

1,880 

 

2,348 

 

2,225 

Ferrari 

Ford 

 

647 

 

1,388 

 

1,201 

 

1,772 

 

1,965 

Fuji (Subaru) 

 

215 

 

789 

 

2,187 

 

3,884 

 

5,451 

General 

Motors 

 

151 

 

1,140 

 

2,178 

 

2,475 

 

2,834 

Honda 

 

279 

 

2,295 

 

2,238 

 

2,850 

 

3,630 

Hyundai 

 

713 

 

1,907 

 

1,984 

 

2,096 

 

2,929 

Lotus 

Maserati 

Mercedes 

 

198 

 

374 

 

391 

 

512 

 

655 

Mitsubishi 

 

204 

 

3,743 

 

3,513 

 

3,417 

 

3,380 

Nissan 

 

215 

 

1,352 

 

1,977 

 

1,992 

 

2,517 

Porsche 

 

143 

 

297 

 

325 

 

435 

 

567 

Suzuki 

 

182 

 

374 

 

385 

 

517 

 

4,263 

Toyota 

 

705 

 

1,407 

 

1,415 

 

1,700 

 

2,174 

Volkswagen 

 

154 

 

308 

 

330 

 

446 

 

578 

Total/Average 

 

501 

 

1,325 

 

1,770 

 

2,171 

 

2,509 
VII-36

Table VII-5l 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Total Cost = Total Benefit 

Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 1,422 1,529 3,288 4,182 3,773 

Ferrari 

Ford 995 2,213 1,979 2,948 3,150 

Fuji (Subaru) 5 54 232 438 628 

General 

Motors 140 2,124 4,631 5,258 5,944 

Honda 184 1,725 1,725 2,258 2,907 

Hyundai 157 502 549 564 818 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 141 136 136 136 

Nissan 57 581 893 898 1,129 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 225 

Toyota 828 1,657 1,764 2,080 2,653 

Volkswagen 0 0 0 0 0 

Total/Average 3,788 10,525 15,196 18,762 21,364 
VII-37

Table VII-5m 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Technology Exhaustion 

Average Cost per Vehicle (2006$) 

Light Trucks 

Manufacturer 

 MY 

2011 

 MY 

2012 

 MY 

2013 

 MY 

2014 

 MY 

2015 

BMW 

 

220 

 

407 

 

638 

 

704 

 

781 

Chrysler 

 

961 

 

1,119 

 

2,093 

 

2,479 

 

2,348 

Ferrari 

Ford 

 

664 

 

1,410 

 

1,912 

 

2,127 

 

2,299 

Fuji (Subaru) 

 

242 

 

827 

 

2,467 

 

4,109 

 

5,511 

General 

Motors 

 

168 

 

1,162 

 

2,349 

 

2,585 

 

2,905 

Honda 

 

301 

 

2,300 

 

3,049 

 

3,499 

 

4,076 

Hyundai 

 

735 

 

1,940 

 

2,220 

 

2,266 

 

3,045 

Lotus 

Maserati 

Mercedes 

 

220 

 

413 

 

644 

 

710 

 

787 

Mitsubishi 

 

231 

 

3,743 

 

3,513 

 

3,505 

 

3,755 

Nissan 

 

237 

 

1,380 

 

2,287 

 

2,263 

 

2,743 

Porsche 

 

165 

 

325 

 

528 

 

578 

 

660 

Suzuki 

 

209 

 

413 

 

671 

 

743 

 

4,400 

Toyota 

 

722 

 

1,429 

 

2,519 

 

2,595 

 

2,930 

Volkswagen 

 

176 

 

341 

 

545 

 

594 

 

677 

Total/Average 

 

536 

 

1,364 

 

2,255 

 

2,507 

 

2,785 
VII-38

Table VII-5n 

Estimated Incremental Costs or Fines over Adjusted Baseline 

Technology Exhaustion 

Total Incremental Costs in Millions (2006$) 

Light Trucks 

Manufacturer 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

BMW 0 0 0 0 0 

Chrysler 1,567 1,674 3,323 4,180 3,827 

Ferrari 

Ford 995 2,213 3,025 3,465 3,721 

Fuji (Subaru) 5 54 232 438 628 

General 

Motors 140 2,124 4,631 5,258 5,944 

Honda 184 1,725 2,299 2,773 3,264 

Hyundai 157 502 549 564 818 

Lotus 

Maserati 

Mercedes 0 0 0 0 0 

Mitsubishi 0 141 136 137 146 

Nissan 57 581 968 973 1,202 

Porsche 0 0 0 0 0 

Suzuki 0 0 0 0 225 

Toyota 828 1,657 3,113 3,263 3,703 

Volkswagen 0 0 0 0 0 

Total/Average 3,933 10,670 18,275 21,051 23,479 
VII-39
VII-40

Financial Impacts of Raising CAFE Standards 

The agency does not have the capability to predict the capital investment needs of the automobile 

industry to install fuel economy technologies, nor the capability to determine the level of capital 

investments available to specific manufacturers in the future. The analysis estimates the price 

increases in total for each manufacturer, under the assumption that prices would be increased and 

the manufacturer would get back that investment when the vehicles are sold. However, that 

methodology does not determine whether automobile manufacturers can pay for research and 

development, plant changes, and tooling necessary to get the technology into the vehicles in the 

first place. In essence this is a cash flow question. Do they have the cash reserves or can they 

borrow enough money to fund this process? The implicit assumption in the analysis is yes. 

A significant portion of the capital needs will fall upon suppliers to the automobile 

manufacturers, those companies that develop and sell engines, transmissions, and other fuel 

economy technologies. So, the capital needs are spread out to both the suppliers and original 

equipment manufacturers. 

The agency would like to have a more informed opinion on the ability of manufacturers to 

provide the capital investment needs for the various alternatives. In light of these unknowns, the 

agency is seeking information regarding the manufacturers financial capabilities in meeting this 

proposal and the alternatives examined. Specific questions are as follows: 

 

QUESTIONS FOR VEHICLE MANUFACTURERS AND SUPPLIERS 

1. For each of the model years 2011-2015, please provide the best possible estimate of the 

incremental capital investments required for your company to comply with the 

alternatives discussed in this analysis (25% Below Optimized, Optimized (7%), 25% 

Above Optimized, 50% Above Optimized, Optimized (3%), TC = TB, and Technology 

Exhaustion. Capital investments are defined here by asset class and consist of outlays for 

property, plant, machinery, equipment, and special tools used in the production process 

by vehicle manufacturers and suppliers. Incremental investments are defined as those 

directly attributed to the fuel economy improvements and would not be incurred in the 

absence of the new requirements. 

2. To the degree possible, please provide the above utilizing the elements below for each 

model year presenting passenger cars and LTV’S separately (suppliers can supply data by 

model year). NHTSA understands that the adoption of flexible assembly in which 

production of passenger cars and many LTV’S are integrated onto the same line may 

make such distinctions infeasible, particularly in the out-years. In such cases, a combined 

PC/ LTV estimate for each element below will suffice. The agency further acknowledges 

that estimates of capital requirements for the out-years must contain, by nature, a high 

degree of uncertainty. 
VII-41

Asset Classification Capital Investment Write-off Period 

 (Incremental) 

New Property $- In years 

Plant $- In years 

Machinery& Equipment $- In years 

Special Tooling $- In years 

3. Please discuss whether you anticipate that your firm will to be able to raise the incremental 

capital investments necessary to meet the levels predicted in answer to the questions above. If 

the answer is no, what level appears likely to be achievable. What alternatives are available to 

raise the incremental capital investments necessary? 

The Impact of Higher Prices on Sales 

Higher fuel economy standards are expected to increase the price of passenger cars and light 

trucks. The potential impact of higher vehicle prices on sales was examined on a manufacturerspecific basis, since the estimated cost of improving fuel economy and the fuel economy 

improvement is different for each manufacturer. There is a broad consensus in the economic 

literature that the price elasticity for demand for automobiles is approximately –1.0.141,142,143

Thus, every one percent increase in the price of the vehicle would reduce sales by one percent. 

Elasticity estimates assume no perceived change in the quality of the product. However, in this 

case, vehicle price increases result from adding technologies that improve fuel economy. If 

consumers do not value improved fuel economy at all, and consider nothing but the increase in 

price in their purchase decisions, then the estimated impact on sales from price elasticity could 

be applied directly. However, we believe that consumers do value improved fuel economy, 

because they reduce the operating cost of the vehicles. We also believe that consumers consider 

other factors that affect their costs and have included these in the analysis. 

To estimate the average value consumers place on fuel savings at the time of purchase, we 

assume that the average purchaser considers the fuel savings they would receive over a 5 year 

timeframe. We chose 5 years because this is the average length of time of a financing 

agreement. 144 The present values of these savings were calculated using a 3 percent discount 

rate, which is more consistent with the real (after-inflation) rate that consumers receive from 

their own personal savings in banks, etc, than the 7 percent discount factor. We used a fuel 

price forecast (see Table VIII-3) that included taxes, because this is what consumers must pay. 

Fuel savings were calculated over the first 5 years and discounted back to a present value. 

 

141 Kleit, A.N. (1990). “The Effect of Annual Changes in Automobile Fuel Economy Standards.” Journal of Regulatory 

Economics, vol. 2, pp 151-172. 142 Bordley, R. (1994). “An Overlapping Choice Set Model of Automotive Price Elasticities,” Transportation Research B, vol 

28B, no 6, pp 401-408. 

143 McCarthy , P.S. (1996). “Market Price and Income Elasticities of New Vehicle Demands,” The Review of 

Economics and Statistics, vol. LXXVII, no. 3, pp. 543-547. 144 National average financing terms for automobile loans are available from the Board of Governors of the Federal 

Reserve System G.19 “Consumer Finance” release. See: http://www.federalreserve.gov/releases/g19/ 
VII-42

The agency believes that consumers may consider several other factors over the 5 year horizon 

when contemplating the purchase of a new vehicle. The agency added these factors into the 

calculation to represent how an increase in technology costs might affect consumers’ buying 

considerations. 

First, consumers might consider the sales taxes they have to pay at the time of purchasing the 

vehicle. We took sales taxes in 2007 by state and weighted them by population by state to 

determine a national weighted-average sales tax of 5.5 percent. 

Second, we considered insurance costs over the 5 year period. More expensive vehicles will 

require more expensive collision and comprehensive (e.g., theft) car insurance. According to the 

National Association of Insurance Commissioners (NAIC) the national average premium for 

collision + comprehensive insurance in 2000 was $389 while the average new car transaction 

price was $20,600. If we assume that this premium is proportional to the new car price, it 

represents about 1.9 percent of the new car price and insurance is paid each year for the five year 

period we are considering for payback. Discounting that stream of insurance costs back to 

present value using a 3 percent discount rate suggests that the present value of the component of 

insurance costs that vary with vehicle price is equal to about 8.0 percent of the vehicle’s price. 

Third, we considered that 70 percent of new vehicle purchasers take out loans to finance their 

purchase. The average new vehicle loan is for 5 years at a 6 percent rate145. At these terms the 

average person taking a loan will pay 16 percent more for their vehicle over the 5 years than a 

consumer paying cash for the vehicle at the time of purchase146. Discounting the additional 3.2 

percent (16 percent / 5 years) per year over the 5 years using a 3 percent mid-year discount 

rate147 results in a discounted present value of 14.87 percent higher for those taking a loan. 

Multiplying that by the 70 percent that take a loan, means that the average consumer would pay 

10.4 percent more than the retail price for loans. 

Fourth, we considered the residual value (or resale value) of the vehicle after 5 years and 

expressed this as a percentage of the new vehicle price. In other words, if the price of the vehicle 

increases due to fuel economy technologies, the resale value of the vehicle will go up 

proportionately. To estimate that value, we looked at 138 model year 2002 vehicles to compare 

their original MSRP values (based on www.nadaguides.com) to their current trade-in values (5 

years later in 2007 based on www.edmunds.com). The sales weighted average residual value for 

this group of vehicles was 37.5 percent. Discounting the residual value back 5 years using a 3 

percent discount rate (37.5 percent * .8755) gives an effective residual value at new of 32.8 

percent. 

These four factors together, the consumer considering he could get 32.8 percent back upon resale 

in 5 years, but will pay 10.4 percent more for loans, 5.5 percent more for taxes and 8.0 percent 

 

145 New car loan rates in 2007 average about 7.8 percent at commercial banks and 4.5 percent at auto finance 

companies, so their average is close to 7 percent 

146 Based on www.bankrate.com auto loan calculator for a 5 year loan at 6 percent. 147 The summation of 3.2 percent x 0.9853 in year one, 3.2 x 0.9566 in year two, 3.2 x 0.9288 in year three, 3.2 x 

0.9017 in year 4, and 3.2 x 0.8755 in year five. 
VII-43

more in insurance, results in a 8.9 percent return on the increase in price for fuel economy 

technology (32.8 percent – 10.4 percent - 5.5 percent – 8.0 percent). Thus, the increase in price 

per vehicle is multiplied by 0.911 (1 – 0.089) before subtracting the fuel savings to determine the 

overall net consumer valuation the increase of costs on his purchase decision. 

Using sales volumes from Automotive News and the Automotive News 2006 Market Data Book 

for base vehicle average prices for MY 2006, we determined an average passenger car and an 

average light truck price per manufacturer. The average base price for all passenger cars using 

this method was $22,857 and for all light trucks was $26,090. While this method does not give 

an exact price, the results are reasonable and specific to individual manufacturers148. These 

prices are in 2006 dollars. Average prices and estimated sales volumes are needed because price 

elasticity is an estimate of how a percent increase in price affects the percent decrease in sales. 

A sample calculation for Ford passenger cars under the Optimized 7% alternative in MY 2011 is 

an estimated retail price increase of $782, which is multiplied by 0.911 to get a residual price 

increase of $712. The estimated fuel savings over the 5 years of $281 at a 3 percent discount rate 

results in a net cost to consumers of $431. Comparing that to the $21,821 average price is 2.39 

percent price increase. Ford sales were estimated to be about 1,300,000 passenger cars for MY 

2011. With a price elasticity of –1.0, a 2.39 percent increase in sales could result in an estimated 

loss in sales of 3,104 passenger cars at a 3 percent discount rate. 

Sales increases occur when the value of improved fuel economy exceeds the consumer cost of 

added technology. Overall, the 25% Below Optimized and the proposed Optimized (7%) 

alternatives result in a gain in sales, while the other alternatives result in almost progressively 

larger losses in sales. Tables VII-6a through 6g show the estimated impact on sales for 

passenger cars and light trucks combined. 

Our projections indicate that CAFE standards will result in sales increases for some 

manufacturers under some scenarios. These results rest on several assumptions about consumer 

behavior, in particular, how consumers value fuel economy increases. If consumers are 

completely unable to perceive any increases in fuel economy, then they would treat the vehicle 

price increases resulting from CAFE standards as pure price increases without any corresponding 

quality increase. Under those circumstances, one would expect vehicle sales to fall in 

accordance with the price elasticity of demand discussed earlier. Our projections of sales 

increases rest on the assumption that consumers will correctly perceive at least some of the 

increase in fuel economy and therefore be willing to pay somewhat more for a vehicle with 

greater fuel economy. Even if consumers value only a portion of the resulting fuel savings, there 

are instances where those fuel savings are nonetheless projected to be large enough to exceed the 

increased vehicle price, thus leading to an increase in sales. However, this assumption raises the 

following question: If some fraction of fuel economy improvements (as perceived and valued by 

vehicle purchasers) is large enough to exceed the increased vehicle cost (and result in an increase 

in vehicle sales), then what would be the nature of the market failure such that those levels of 

fuel economy would not exist but for a CAFE mandate? To better understand this issue, NHTSA 

 

148 The base price does not include the more expensive lines of a model or purchased optional equipment; nor does 

it count discounts given. Thus, it is not an average light truck purchase transaction price, but a price that we can 

track. 
VII-44

seeks comment on the following questions: What evidence or data exist that indicate the extent 

to which consumers undervalue fuel economy improvements? Under what circumstances is it 

reasonable to expect that a mandated increase in fuel economy would lead to an increase in 

vehicle sales? 

Note that there is no feedback loop between this sales analysis and the Volpe model. These sales 

estimates are not used to determine additional or less mileage traveled or fuel consumed. Also, 

see the earlier discussion about a market share model in Chapter V. 
VII-45

Table VII-6a 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

25% Below Optimized 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -1,408 -1,528 -1,520 -1,497 -2,038 

Chrysler 17,429 14,748 20,295 12,675 8,732 

Ferrari -5 -8 -13 -17 -21 

Ford 10,813 16,693 24,406 25,835 26,704 

Fuji (Subaru) -1,913 -2,454 -5,948 -11,872 -14,118 

General Motors -3,797 -10,067 12,302 23,018 16,005 

Honda 4,820 10,573 14,410 14,877 15,049 

Hyundai -4,103 1,475 4,404 7,216 9,698 

Lotus -32 -34 -40 -43 -46 

Maserati 0 -3 -7 -11 -14 

Mercedes -864 -1,159 -1,645 -222 -328 

Mitsubishi 29 -1,468 -1,456 -1,537 -2,044 

Nissan -2,089 1,330 132 2,673 5,279 

Porsche -512 -543 -631 -675 -725 

Suzuki -321 -50 -373 -1,497 -4,764 

Toyota 11,977 20,734 26,551 27,361 27,659 

Volkswagen -2,195 -1,979 912 329 980 

Total/Average 27,828 46,262 91,779 96,615 86,009 
VII-46

Table VII-6b 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

Proposed Optimized (7%) Alternative 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -2,258 -2,910 -2,691 -2,540 -3,000 

Chrysler 17,331 14,665 10,741 13,423 9,536 

Ferrari -11 -17 -21 -24 -27 

Ford 8,551 19,365 26,032 29,032 33,226 

Fuji (Subaru) -2,629 -3,623 -6,938 -12,359 -14,611 

General Motors -2,230 -8,057 14,642 17,547 17,554 

Honda 4,764 7,891 11,720 16,296 20,396 

Hyundai -2,120 5,283 4,690 5,361 5,893 

Lotus -43 -51 -55 -55 -57 

Maserati -4 -10 -13 -16 -20 

Mercedes -1,290 -1,837 -2,228 -779 -831 

Mitsubishi -719 -2,662 -2,588 -2,751 -3,134 

Nissan 230 5,842 3,615 5,338 2,525 

Porsche -652 -771 -831 -845 -878 

Suzuki -485 -349 -616 -1,726 -6,925 

Toyota 12,245 19,544 24,826 22,455 26,886 

Volkswagen -3,840 -4,587 -1,350 -1,659 -763 

Total/Average 26,839 47,716 78,935 86,698 85,769 
VII-47

Table VII-6c 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

25% Supra Alternative 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -3,123 -4,309 -3,862 -3,644 -4,025 

Chrysler 9,912 6,334 -6,223 -6,195 -24,075 

Ferrari -17 -26 -29 -31 -33 

Ford 7,370 16,682 19,573 12,529 7,087 

Fuji (Subaru) -3,367 -4,857 -7,907 -16,928 -19,038 

General Motors -30,508 -61,856 -45,558 -58,594 -66,337 

Honda 4,722 1,920 3,970 9,350 9,244 

Hyundai 1,088 1,979 830 612 2,889 

Lotus -54 -69 -70 -69 -69 

Maserati -9 -16 -19 -21 -24 

Mercedes -1,711 -2,535 -2,786 -1,355 -1,428 

Mitsubishi -1,815 -4,997 -4,703 -5,029 -5,234 

Nissan -5,783 -13,221 -16,419 -15,875 -22,833 

Porsche -799 -1,006 -1,025 -1,027 -1,033 

Suzuki -666 -672 -840 -2,024 -8,197 

Toyota 11,809 5,470 10,213 10,327 16,675 

Volkswagen -5,569 -7,281 -3,531 -3,651 -2,513 

Total/Average -18,519 -68,461 -58,385 -81,627 -118,944 
VII-48

Table VII-6d 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

50% Supra Alternative 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -3,972 -5,691 -5,271 -5,028 -5,478 

Chrysler -558 -7,331 -20,508 -31,632 -49,142 

Ferrari -23 -35 -37 -38 -39 

Ford -1,342 4,579 12,174 -1,025 -7,272 

Fuji (Subaru) -4,062 -6,079 -9,228 -16,956 -19,945 

General Motors -36,279 -72,169 -75,782 -95,110 -114,136 

Honda 8,507 -14,076 -12,017 -6,609 -15,842 

Hyundai 1,587 -19,379 -18,338 -19,135 -19,963 

Lotus -66 -87 -91 -92 -96 

Maserati -13 -23 -24 -25 -26 

Mercedes -2,113 -3,214 -3,427 -1,965 -2,052 

Mitsubishi -1,943 -4,681 -4,943 -5,341 -5,587 

Nissan -12,560 -25,212 -34,257 -39,264 -47,405 

Porsche -951 -1,247 -1,293 -1,324 -1,386 

Suzuki -824 -977 -1,170 -2,439 -9,160 

Toyota 6,218 11,832 16,778 11,296 8,569 

Volkswagen -7,214 -9,970 -6,437 -6,670 -5,907 

Total/Average -55,606 -153,761 -163,872 -221,357 -294,866 

 
VII-49

Table VII-6e 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

Optimized (3%) 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -5,396 -6,246 -5,557 -5,605 -5,683 

Chrysler 10,327 7,841 -7,235 -6,240 -10,436 

Ferrari -33 -41 -40 -45 -45 

Ford 6,495 16,042 25,196 27,749 30,897 

Fuji (Subaru) -5,227 -6,376 -9,419 -15,516 -17,566 

General Motors -45,165 -73,656 -53,602 -66,812 -74,776 

Honda 37 -9,614 -6,242 -2,122 -840 

Hyundai -22,801 -20,020 -20,005 -20,067 -17,556 

Lotus -84 -95 -94 -93 -93 

Maserati -21 -26 -26 -31 -32 

Mercedes -2,772 -3,449 -3,581 -2,279 -2,156 

Mitsubishi -2,161 -4,807 -5,020 -5,457 -5,661 

Nissan -17,337 -25,420 -36,520 -47,914 -54,454 

Porsche -1,182 -1,333 -1,334 -1,340 -1,344 

Suzuki -1,043 -933 -1,151 -2,291 -8,889 

Toyota 21,822 41,006 46,381 44,740 49,292 

Volkswagen -10,333 -11,415 -7,316 -7,598 -6,260 

Total/Average -74,873 -98,542 -85,566 -110,920 -125,605 
VII-50

Table VII-6f 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

Total Costs = Total Benefit Alternative 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -5,733 -8,456 -7,659 -7,327 -7,635 

Chrysler -10,937 -23,499 -54,877 -75,745 -73,164 

Ferrari -34 -53 -52 -52 -52 

Ford -9,599 -21,475 -14,836 -30,982 -35,388 

Fuji (Subaru) -5,618 -8,643 -11,398 -21,785 -27,766 

General Motors -48,581 -92,408 -109,370 -126,542 -148,076 

Honda -10,825 -53,233 -53,413 -66,008 -77,005 

Hyundai -23,599 -46,485 -46,833 -53,290 -57,145 

Lotus -91 -126 -125 -124 -125 

Maserati -22 -36 -36 -36 -36 

Mercedes -2,935 -4,557 -4,569 -3,118 -3,226 

Mitsubishi -2,226 -5,991 -6,195 -6,590 -6,807 

Nissan -18,595 -37,982 -48,329 -58,123 -65,615 

Porsche -1,269 -1,746 -1,737 -1,742 -1,761 

Suzuki -1,194 -1,612 -1,674 -3,066 -10,532 

Toyota 6,846 -26,703 -20,917 -30,747 -38,504 

Volkswagen -10,754 -15,514 -11,362 -11,204 -9,951 

Total/Average -145,167 -348,520 -393,382 -496,484 -562,788 
VII-51

Table VII-6g 

Potential Impact on Sales by Manufacturer 

Passenger Cars and Light Trucks Combined 

Technology Exhaustion Alternative 

Manufacturer MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

BMW -6,280 -9,901 -10,977 -10,963 -12,440 

Chrysler -16,765 -30,229 -71,831 -89,064 -85,899 

Ferrari -39 -63 -74 -77 -85 

Ford -10,835 -23,723 -30,037 -35,235 -38,953 

Fuji (Subaru) -6,152 -10,007 -14,838 -25,105 -31,500 

General Motors -53,560 -103,483 -142,788 -160,265 -186,507 

Honda -16,012 -62,105 -76,863 -88,495 -101,441 

Hyundai -25,559 -50,981 -57,543 -69,209 -75,562 

Lotus -95 -144 -160 -159 -178 

Maserati -25 -42 -52 -56 -62 

Mercedes -3,242 -5,328 -6,511 -5,204 -5,764 

Mitsubishi -2,376 -6,250 -6,667 -7,222 -8,018 

Nissan -20,935 -43,571 -63,048 -74,077 -84,875 

Porsche -1,328 -1,975 -2,219 -2,226 -2,474 

Suzuki -1,335 -1,948 -2,798 -4,077 -11,575 

Toyota 2,665 -115,685 -147,858 -175,571 -195,117 

Volkswagen -11,912 -18,533 -17,317 -17,503 -18,843 

Total/Average -173,784 -483,968 -651,580 -764,510 -859,291 
VII-52

Table VII-6h 

Potential Impact on Sales 

Passenger Cars versus Light Trucks by Alternative 

MY 2015 

 Passenger Cars Light Trucks Total 

25% Below Optimized 22,237 63,773 86,009 

Optimized (7%) 21,482 64,288 85,769 

25% Above Optimized -48,921 -70,024 -118,944 

50% Above Optimized -138,449 -156,417 -294,866 

Optimized (3%) -170,031 44,426 -125,605 

TC = TB -293,326 -269,462 -562,788 

Technology Exhaustion -557,905 -301,386 -859,291 
VII-53

Potential Impact on Employment 

There are three potential areas of employment that fuel economy standards could impact. The 

first is the hiring of additional engineers by automobile companies and their suppliers to do 

research and development and testing on new technologies to determine their capabilities, 

durability, platform introduction, etc. The agency does not anticipate a huge number of 

incremental jobs in the engineering field. Often people would be diverted from one area to 

another and the incremental number of jobs might be a few thousand. 

The second area is the impact that new technologies would have on the production line. Again, 

we don’t anticipate a large number of incremental workers, as for the most part you are replacing 

one engine with another or one transmission with another. In some instances the technology is 

more complex, requiring more parts and there would be a small increase in the number of 

production employees, but we don’t anticipate a large change. 

The third area is the potential impact that sales gains or losses could have on production 

employment. This area is potentially much more sensitive to change than the first two areas 

discussed above. In the past, the agency and others have made estimates of the impact of sales 

losses on employment. In the final rule reducing the light truck fuel economy standard for MY 

1985, the agency concluded that sales losses of 100,000 to 180,000 would result in employment 

losses of 12,000 to 23,000 (49 FR 41252, October 22, 1984).149 In the final rule reducing the 

MY 1986 passenger car fuel economy standard, the agency concluded that while it was difficult 

to precisely estimate the impacts, “there would be a likelihood of sales losses well into the 

hundreds of thousands of units and job losses well into the tens of thousands. Sales and 

employment losses of these magnitudes would have significant adverse effects on the economy 

... ” (50 FR 40538, October 4, 1985). In the final rule amending the passenger car standards for 

MY 1987 and 1988, the agency said that “... domestic car production may fall by more than 

900,000 units. The short employment effects are substantial: over 130,000 jobs...” (51 FR 

35598, October 6, 1986). These estimates imply a ratio between the number of vehicles sales 

lost and the number of employees laid off in the 1980s of between 6.9 (900,000/130,000) and 8.3 

(100,000/12,000). 

Certainly productivity has increased since that time. In order to get an estimate of potential job 

losses per sales loss, we examined more recent U.S. employment (original equipment 

manufacturers and suppliers) and U.S. production. Total employment in 2000 reached a peak in 

the Motor Vehicle and Equipment Manufacturing sector of the economy at 1,313,600. Since 

then there has been a decline to 1,108,000 in 2003 and to 1,098,000 in 2005150. Averaging those 

three years, the average U.S. domestic employee produces 10.5 vehicles. Thus, one could 

assume that projected sales loss divided by 10.5 would give an estimate of the potential 

employment loss. 

 

149 The agency’s decision to lower standards based on that amount of impacts identified in the 1985 rule was upheld 

by the DC Circuit in Public Citizen v. NHTSA, 848 F.2d 256. 

150 Based on “U.S. Automotive Industry Employment Trends”, Office of Aerospace and Automotive Industries, U.S. 

Department of Commerce, March 30, 2005, and Ward’s Automotive Yearbook, 2006, pgs. 215, 222, and 270. 
VII-54

Table VII-7 

U.S. Light Duty Vehicle Production and Employment 

U.S. Light Vehicle 

Production U.S. Employment 

Production per 

Employee 

2000 12,773,714 1,313,600 9.7 

2003 12,087,028 1,108,000 10.9 

2005 11,946,653 1,098,000 10.9 

Total/Average 36,807,396 3,519,600 10.5 

 

At this time, the agency considers these effects to occur in the short to medium term (meaning up 

to 5 years). Over the next few years, consumers can elect to defer vehicle purchases by 

continuing to operate existing vehicles. Eventually, however, the rising maintenance costs for 

aging vehicles will make replacements look more attractive. 

However, vehicle owners may also react to persistently higher vehicle costs by permanently 

owning fewer vehicles, and keeping existing vehicles in service for somewhat longer. In this 

case, the possibility exists that there may be permanent sales losses, compared with a situation in 

which vehicle prices are lower. 

The 25% Sub Optimizes and the proposed Optimized (7%) alternative would have positive 

impacts on employment. The other alternatives have negative impacts on employment. 

Combining the sales effect on passenger cars and light trucks, the impact on employment is 

estimated in the following table. 
VII-55

Table VII-8 

Impact on Auto Industry Employment by Alternative 

(Jobs) 

Passenger Cars 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

25% Below 

Optimized -409 1,151 1,835 2,632 2,118

Optimized (7%) -327 1,941 2,148 2,689 2,046

25% Above 

Optimized -25,822 -33,273 -31,777 -31,082 -32,614

50% Above 

Optimized -5,407 -10,527 -10,782 -11,887 -13,186

Optimized (3%) -9,972 -12,054 -12,381 -14,919 -16,193

TC = TB -11,760 -22,413 -23,420 -26,578 -27,936

Technology 

Exhaustion -13,587 -34,289 -40,892 -47,829 -53,134

 

Light Trucks 

25% Below 

Optimized 3,059 3,255 6,906 6,569 6,074

Optimized (7%) 2,883 2,604 5,370 5,568 6,123

25% Above 

Optimized 1,925 -1,767 -1,021 -3,334 -6,669

50% Above 

Optimized 111 -4,117 -4,825 -9,195 -14,897

Optimized (3%) 2,841 2,669 4,232 4,356 4,231

TC = TB -2,066 -10,779 -14,045 -20,706 -25,663

Technology 

Exhaustion -2,964 -11,803 -21,163 -24,982 -28,703

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 2,650 4,406 8,741 -9,201 8,191

Optimized (7%) 2,556 4,544 7,518 -8,257 8,169

25% Above 

Optimized -1,764 -6,520 -5,561 7,774 -11,328

50% Above 

Optimized -5,296 -14,644 -15,607 21,082 -28,082

Optimized (3%) -7,131 -9,385 -8,149 10,564 -11,962

TC = TB -13,825 -33,192 -37,465 47,284 -53,599

Technology 

Exhaustion -16,551 -46,092 -62,055 72,810 -81,837
VII-56

Table VII-9 provides further information relating to the stringency of the different alternatives. 

It looks at the largest 7 manufacturers and examines whether or not they run out of technologies 

that the agency believes they have available. As the alternatives get more stringent, more 

manufacturers run out of technologies. 

Table VII-9 

Number of Manufacturers That Run out of Technology 

 Cars: Number of Manufacturers Exhausting Technology 

 2011 2012 2013 2014 2015 

-25% 0 0 1 0 0 

MC=MB 1 0 1 0 2 

+25% 2 2 2 1 2 

+50% 4 4 4 2 3 

TC=TB 5 6 6 5 5 

Technology 

Exhaustion 

6 6 6 6 7 

 Trucks: Number of Manufacturers Exhausting Technology 

 2011 2012 2013 2014 2015 

-25% 3 2 0 1 0 

MC=MB 3 2 0 1 0 

+25% 3 3 0 4 3 

+50% 4 3 0 4 5 

TC=TB 6 6 2 6 6 

Technology 

Exhaustion 

7 6 6 6 6 
VIII-1

VIII. BENEFITS

Economic Impacts from Higher CAFE Standards 

Economic impacts from adopting a more stringent CAFE standard for passenger cars and light 

trucks were estimated separately for each model year over the lifespan of those vehicles in the 

U.S. vehicle fleet, extending from the initial year when a model is offered for sale through the 

year when nearly all vehicles from that model year have been retired or scrapped (assumed to be 

26 years for passenger cars and 36 years for light trucks in this analysis). The principal source of 

the economic and environmental impacts considered in this analysis is the reduction in gasoline 

use resulting from the improvement in fuel economy of new light-duty vehicles produced. 

Reducing gasoline consumption provides consumer benefits through decreased fuel costs, 

through reduced costs for externalities such as demand price inflation, economic disruption, and 

military security, through reduced economic and health impacts from criteria pollutants and 

green house gas emissions, through increased driving ranges for vehicles, and through consumer 

surplus from added driving. Offsetting a part of these benefits are added costs from congestion, 

crashes, and noise, as well as some offset to fuel consumption and pollution savings, all due to an 

increase in driving that results from lower driving costs (the rebound effect). Each of these 

impacts is measured by comparing their value under each alternative approach to their value 

under the adjusted baseline. Future impacts are estimated after discounting to the year the 

vehicle is sold to determine their present value.151 

Basic Inputs for Analysis of Economic Impacts 

The variety of impacts discussed above are a function of basic factors which determine their 

magnitude and define their value. These include the discount rate, the level of vehicle sales, the 

magnitude of the rebound effect, and the relationship between EPA measured fuel efficiency and 

actual on-road fuel efficiency. 

The Discount Rate

Discounting future fuel savings and other benefits is intended to account for the reduction in their value to 

society when they are deferred until some future date rather than received immediately. The discount rate 

expresses the percent decline in the value of these benefits – as viewed from today’s perspective – for 

each year they are deferred into the future. Discount rates are used in a variety of analyses that address 

different aspects of benefit valuation. These include: 1) selecting a set of standards 2) analyzing the 

impact of those standards 3) examining the impact of uncertainty surrounding our choice of rates used to 

analyze impacts, and 4) determining the sensitivity of standards selection to the discount rate. However, 

the agency must select one specific rate to set the standards. The agency uses a rate of 7 percent per year 

to discount the value of future fuel savings and other benefits when it analyzes the potential impacts of 

alternative passenger car and light truck CAFE standards. OMB Circular A-4 requires that the agency 

examine costs and benefits of proposed standards using discount rates of both 3 percent and 7 percent. 

The 3 percent rate generally represents the consumer rate of time preference while the 7 percent rate 

generally represents the economy-wide opportunity cost of capital. Benefits based on both of these rates 

are presented to value the benefits that are associated with the standards set in this proposal. The agency 

 

151 Discounting to the year when each model year was produced allows future economic benefits from improving 

each model year’s fuel economy to be compared to added production costs for making those vehicles more fuelefficient, which are assumed to be incurred at the time those vehicles are manufactured. 
VIII-2

uses discount rates ranging from 3 percent to 10 percent per year to analyze the uncertainty surrounding 

the future impacts of alternative standards. 

There are several reasons for the agency’s choice of 7 percent as the appropriate discount rate to 

determine the standards. First, OMB Circular A-4 indicates that this rate reflects the economywide opportunity cost of capital. The agency believes that a substantial portion of the cost of this 

regulation may come at the expense of other investments the auto manufacturers might otherwise 

make. Several large manufacturers are resource-constrained with respect to their engineering 

and product-development capabilities. As a result, other uses of these resources will be foregone 

while they are required to be applied to technologies that improve fuel economy. 

Second, 7 percent also appears to be an appropriate rate to the extent that the costs of the 

regulation come at the expense of consumption as opposed to investment. The agency believes 

that financing rates on vehicle loans represent an appropriate discount rate, because they reflect 

the opportunity costs faced by consumers when buying vehicles with greater fuel economy and a 

higher purchase price. Most new and used vehicle purchases are financed, and because most of 

the benefits from higher fuel economy standards accrue to vehicle purchasers in the form of fuel 

savings, the appropriate discount rate is the interest rate buyers pay on loans to finance their 

vehicle purchases.152 

According to the Federal Reserve, the interest rate on new car loans made through commercial 

banks has closely tracked the rate on 10-year treasury notes, but exceeded it by about 3 

percent.153 The official Administration forecast is that real interest rates on 10-year treasury 

notes will average about 3 percent through 2016, implying that 6 percent is a reasonable forecast 

for the real interest rate on new car loans.154 In turn, the interest rate on used car loans made 

through automobile financing companies has closely tracked the rate on new car loans made 

through commercial banks, but exceeded it by about 3 percent.155 (The agency believes it is 

important to consider rates on loans that finance used car purchases, because some of the fuel 

savings resulting from improved fuel economy accrue to used car buyers.) Given the 6 percent 

estimate for new car loans, a reasonable forecast for used car loans is thus 9 percent. 

Because the benefits of fuel economy accrue to both new and used car owners, a discount rate 

between 6 percent and 9 percent is thus appropriate for evaluating future benefits resulting from 

higher fuel economy. Assuming that new car buyers discount fuel savings at 6 percent for 5 

years (the average duration of a new car loan) 156 and that used car buyers discount fuel savings 

at 9 percent for 5 years (the average duration of a used car loan)157, the single constant discount 

rate that yields equivalent present value fuel savings is very close to 7 percent. 

 

152 Empirical evidence also demonstrates that used car purchasers do pay for greater fuel economy (Kahn, Quarterly 

Journal of Economics, 1986). 

153 See, http://www.federalreserve.gov/releases/g20/hist/fc_hist_tc.txt. 

154 See, http://www.federalreserve.gov/releases/h15/data/Monthly/H15_TCMNOM_Y10.txt. 

155 See, http://www.federalreserve.gov/releases/g20/hist/fc_hist_tc.txt. 

156 Id. 

157 Id. 
VIII-3

However, the Agency recognizes that there are arguments for using 3 percent as well. Namely 

that OMB requests benefits to be estimated at both 3 percent as well as 7 percent and that the 

official Administration forecast is that real interest rates on 10-year treasury notes will average 

about 3 percent through 2016. Although the agency feels that the arguments for 7% are stronger, 

we have calculated results under both 3% and 7% to demonstrate the impact of the lower 

discount rate on the resulting standards. 

Sales Projections

A critical variable affecting the total economic benefits from improving light truck fuel economy 

is the number of vehicles likely to be produced under stricter fuel economy. Projections of total 

passenger cars and light truck sales for future years (see Table VIII-1a and VIII-1b) were 

obtained from the Energy Information Administration’s (EIA) Annual Energy Outlook 2007 

(AEO 2007), a standard government reference for projections of energy production and 

consumption in different sectors of the U.S. economy.158 NHTSA estimated the sales by 

manufacturer, based on their market shares in the NHTSA MY2006 CAFE data base. These 

values will be used as multipliers to estimate the overall impacts (both costs and benefits) of 

changes in fuel economy standards. 

 

158 U.S. Department of Energy, Energy Information Administration, Annual Energy Outlook 2007, Supplemental 

Table 47, http://www.eia.doe.gov/oiaf/aeo/supplement/suptab_47.xls. 
VIII-4

Table VIII-1a 

Sales Projections – Passenger Cars 

(1,000s of vehicles) 

2011 2012 2013 2014 2015 

BMW 

 

187.2 

 

185.2 

 

183.6 

 

180.2 

 

178.6 

Mercedes 

 

184.9 

 

182.9 

 

181.3 

 

177.9 

 

176.3 

Chrysler 

 

571.9 

 

551.9 

 

569.0 

 

554.0 

 

546.7 

Ferrari 

 

1.7 

 

1.7 

 

1.7 

 

1.7 

 

1.6 

Ford 

 

1,430.5 

 

1,415.3 

 

1,402.9 

 

1,376.8 

 

1,364.7 

Fuji 

(Subaru) 

 

137.3 

 

135.8 

 

134.7 

 

132.2 

 

131.0 

General 

Motors 

 

2,014.0 

 

2,000.9 

 

1,985.3 

 

1,951.0 

 

1,935.0 

Honda 

 

916.6 

 

906.8 

 

898.9 

 

882.2 

 

874.4 

Hyundai/Kia 

 

477.5 

 

472.4 

 

468.3 

 

459.6 

 

455.5 

Lotus 

 

3.7 

 

3.6 

 

3.6 

 

3.5 

 

3.5 

Maserati 

 

2.3 

 

2.3 

 

2.3 

 

2.2 

 

2.2 

Mitsubishi 

 

75.7 

 

74.9 

 

74.2 

 

72.8 

 

72.2 

Nissan 

 

721.6 

 

713.9 

 

707.7 

 

694.5 

 

688.4 

Porsche 

 

16.1 

 

15.9 

 

15.7 

 

15.5 

 

15.3 

Suzuki 

 

64.5 

 

63.8 

 

63.2 

 

62.0 

 

61.5 

Toyota 

 

1,500.4 

 

1,483.3 

 

1,470.3 

 

1,443.0 

 

1,430.2 

Volkswagen 

 

274.0 

 

271.1 

 

268.7 

 

263.7 

 

261.4 

Total 8,579.6 8,481.7 8,431.2 8,272.8 8,198.5 
VIII-5

Table VIII-1b 

Sales Projections – Light Trucks 

 (1,000s of vehicles) 

2011 2012 2013 2014 2015 

BMW 66.5 

 

68.4 

 

70.1 

 

72.1 

 

72.9 

Mercedes 21.4 

 

22.0 

 

22.6 

 

23.2 

 

23.5 

Chrysler 1899.9 

 

1,953.4 

 

2,002.6 

 

2,058.9 

 

2,081.3 

Ford 1559.6 

 

1,644.6 

 

1,686.0 

 

1,733.4 

 

1,752.3 

Fuji (Subaru) 84.6 

 

86.9 

 

89.0 

 

91.4 

 

92.4 

General Motors 2159.2 

 

2,213.6 

 

2,269.3 

 

2,333.0 

 

2,358.4 

Honda 570.7 

 

586.8 

 

601.5 

 

618.4 

 

625.2 

Hyundai 298.5 

 

306.9 

 

314.6 

 

323.5 

 

327.0 

Mitsubishi 40.4 

 

41.5 

 

42.5 

 

43.7 

 

44.2 

Nissan 446.3 

 

417.3 

 

429.6 

 

443.6 

 

449.2 

Porsche 14.6 

 

15.0 

 

15.4 

 

15.9 

 

16.0 

Suzuki 25.0 

 

25.7 

 

26.3 

 

27.1 

 

27.3 

Toyota 963.1 

 

990.2 

 

1,015.2 

 

1,043.7 

 

1,055.1 

Volkswagen 23.4 

 

24.0 

 

24.6 

 

25.3 

 

25.6 

 

Total 8213.1 8,396.4 8,609.4 8,853.2 8,950.3 

The “Rebound Effect” 

The rebound effect refers to the tendency for owners to increase the number of miles they drive a 

vehicle in response to an increase in its fuel economy, as would result from more stringent fuel 

economy standards. The rebound effect occurs because an increase in a vehicle’s fuel economy 

reduces its owner’s fuel cost for driving each mile, which is typically the largest single 

component of the cost of operating a vehicle. Even with the vehicle’s higher fuel economy, this 

additional driving uses some fuel, so the rebound effect will reduce the net fuel savings that 

result when the fuel economy standards require manufacturers to increase fuel economy. The 

rebound effect is usually expressed as the percentage by which annual vehicle use increases 

when average fuel cost per mile driven decreases in response to a change in the marginal cost of 

driving an extra mile, due either an increase in fuel economy or a reduction in the price of fuel. 
VIII-6

The magnitude of the rebound effect is one of the determinants of the actual fuel savings that are 

likely to result from adopting stricter standards, and thus an important parameter affecting 

NHTSA’s evaluation of alternative standards for future model years. The rebound effect can be 

measured directly by estimating the elasticity of vehicle use with respect to fuel economy itself, 

or indirectly by the elasticity of vehicle use with respect to fuel cost per mile driven.159 When 

expressed as a positive percentage, either of these parameters gives the fraction of fuel savings 

that would otherwise result from adopting stricter standards, but is offset by the increase in fuel 

consumption that results when vehicles with increased fuel economy are driven more. 

Research on the magnitude of the rebound effect in light-duty vehicle use dates to the early 

1980s, and almost unanimously concludes that a statistically significant rebound effect occurs 

when vehicle fuel efficiency improves.160 The most common approach to estimating its 

magnitude has been to analyze statistically household survey data on vehicle use, fuel 

consumption, fuel prices (often obtained from external sources), and other determinants of 

household travel demand to isolate the response of vehicle use to higher fuel economy. Other 

studies have relied on econometric analysis of annual U.S. data on vehicle use, fuel economy, 

fuel prices, and other variables to identify the response of total or average vehicle use to changes 

in fleet-wide average fuel economy and its effect of fuel cost per mile driven. Two recent studies 

analyzed yearly variation in vehicle ownership and use, fuel prices, and fuel economy among 

individual states over an extended time period in order to measure the response of vehicle use to 

changing fuel economy.161 

An important distinction among studies of the rebound effect is whether they assume that the 

effect is constant, or varies over time in response to the absolute levels of fuel costs, personal 

income, or household vehicle ownership. Most studies using aggregate annual data for the U.S. 

assume a constant rebound effect, although some of these studies test whether the effect can vary 

as changes in retail fuel prices or average fuel economy alter fuel cost per mile driven. Many 

studies using household survey data estimate significantly different rebound effects for 

households owning varying numbers of vehicles, although they arrive at differing conclusions 

about whether the rebound effect is larger among households that own more vehicles. One 

recent study using state-level data concludes that the rebound effect varies directly in response to 

changes in personal income and the degree of urbanization of U.S. cities, as well as fuel costs. 

In order to arrive at a preliminary estimate of the rebound effect for use in assessing the fuel 

savings, emissions reductions, and other impacts of alternative standards, NHTSA reviewed 22 

studies of the rebound effect conducted from 1983 through 2005. We then conducted a detailed 

analysis of the 66 separate estimates of the long-run rebound effect reported in these studies, 

 

159 Fuel cost per mile is equal to the price of fuel in dollars per gallon divided by fuel economy in miles per gallon, 

so this figure declines when a vehicle’s fuel economy increases. 

160 Some studies estimate that the long-run rebound effect is significantly larger than the immediate response to 

increased fuel efficiency. Although their estimates of the adjustment period required for the rebound effect to reach 

its long-run magnitude vary, this long-run effect is most appropriate for evaluating the fuel savings and emissions 

reductions resulting from stricter standards that would apply to future model years. 

161 In effect, these studies treat U.S. states as a data “panel” by applying appropriate estimation procedures to data 

consisting of each year’s average values of these variables for the separate states. 
VIII-7

which is summarized in the table below.162 As the table indicates, these 66 estimates of the longrun rebound effect range from as low as 7 percent to as high as 75 percent, with a mean value of 

23 percent. 

Limiting the sample to 50 estimates reported in the 17 published studies of the rebound effect 

yields the same range but a slightly higher mean (24 percent), while focusing on the authors’ 

preferred estimates from published studies narrows this range and lowers its average only 

slightly. The median estimate of the rebound effect in all three samples, which is generally 

regarded as a more reliable indicator of their central tendency than the average because it is less 

influenced by unusually small and large estimates, is 22 percent. As Table 13 indicates, 

approximately two-thirds of all estimates reviewed, of all published estimates, and of authors’ 

preferred estimates fall in the range of 10-30 percent. 

Table VIII-1c 

Summary of Rebound Effect Estimates 

Category of Estimates Number of Range Distribution 

Studies 

Number of 

Estimates 

Low High Median Mean Std. Dev.

All Estimates 22 66 7% 75% 22% 23% 14% 

Published Estimates 17 50 7% 75% 22% 24% 14% 

Authors' Preferred Estimates 17 17 9% 75% 22% 22% 15% 

U.S. Time-Series Estimates 7 34 7% 45% 14% 18% 9% 

Household Survey Estimates 13 23 9% 75% 31% 31% 16% 

Pooled U.S. State Estimates 2 9 8% 58% 22% 25% 14% 

Constant Rebound Effect (1) 15 37 7% 75% 20% 23% 16% 

Variable Rebound Effect: (1) 

Reported Estimates 10 29 10% 45% 23% 23% 10% 

Updated to 2006 (2) 10 29 6% 46% 16% 19% 12% 

(3) Three studies estimate both constant and variable rebound effects. 

(4) Reported estimates updated to reflect 2006 values of vehicle use, fuel prices, fleet 

fuel efficiency, household income, and household vehicle ownership. 

The type of data used and authors’ assumption about whether the rebound effect varies over time 

have important effects on its estimated magnitude. The 34 estimates derived from analysis of 

U.S. annual time-series data produce a median estimate of 14 percent for the long-run rebound 

effect, while the median of 23 estimates based on household survey data is more than twice as 

large (31 percent), and the median of 9 estimates based on pooled state data matches that of the 

entire sample (22 percent). The 37 estimates assuming a constant rebound effect produce a 

median of 20 percent, while the 29 originally reported estimates of a variable rebound effect 

have a slightly higher median value (23 percent). 

 

162 In some cases, NHTSA derived estimates of the overall rebound effect from more detailed results reported in the 

studies. For example, where studies estimated different rebound effects for households owning different numbers 

of vehicles but did not report an overall value, we computed a weighted average of the reported values using the 

distribution of households among vehicle ownership categories. 
VIII-8

In selecting a single value for the rebound effect to use in analyzing alternative standards for 

future model years, NHTSA tentatively attaches greater significance to studies that allow the 

rebound effect to vary in response to changes in the various factors that have been found to affect 

its magnitude. However, it is also important to update authors’ originally-reported estimates of 

variable rebound effects to reflect current conditions. Recalculating the 29 original estimates of 

variable rebound effects to reflect current (2006) values for retail fuel prices, average fuel 

economy, personal income, and household vehicle ownership reduces their median estimate to 

16 percent.163 NHTSA also tentatively attaches greater significance to the recent study by Small 

and Van Dender (2005), which finds that the rebound effect tends to decline as average fuel 

economy, personal income, and suburbanization of U.S. cities increase, but – in accordance with 

previous studies – rises with increasing fuel prices.164

Considering the empirical evidence on the rebound effect as a whole, but according greater 

importance to the updated estimates from studies allowing the rebound effect to vary – 

particularly the Small and Van Dender study – NHTSA has selected a rebound effect of 15 

percent to evaluate the fuel savings and other effects of alternative standards for the time period 

covered by this rulemaking. However, we do not believe that evidence of the rebound effect’s 

dependence on fuel prices or household income is sufficiently convincing to justify allowing its 

future value to vary in response to forecast changes in these variables. A range extending from 

10 percent to at least 20 percent -- and perhaps as high as 25 percent -- appears to be appropriate 

for the required analysis of the uncertainty surrounding these estimates. 

On-Road Fuel Economy Adjustment

Actual fuel economy levels achieved by vehicles in on-road driving fall significantly short of 

their levels measured under the laboratory-like test conditions used by EPA to establish its 

 

163 As an illustration, Small and Van Dender (2005) allow the rebound effect to vary over time in response to 

changes in real per capita income as well as average fuel cost per mile driven. While their estimate for the entire 

interval (1966-2001) they analyze is 22 percent, updating this estimate using 2006 values of these variables reduces 

the rebound effect to approximately 10 percent. Similarly, updating Greene’s 1992 original estimate of a 15 percent 

rebound effect to reflect 2006 fuel prices and average fuel economy reduces it to 6 percent. See David L. Greene, 

“Vehicle Use and Fuel Economy: How Big is the Rebound Effect?” The Energy Journal, 13:1 (1992), 117-143. In 

contrast, the distribution of households among vehicle ownership categories in the data samples used by Hensher et 

al. (1990) and Greene et al. (1999) are nearly identical to the most recent estimates for the U.S., so updating their 

original estimates to current U.S. conditions changes them very little. See David A. Hensher, Frank W. Milthorpe, 

and Nariida C. Smith, “The Demand for Vehicle Use in the Urban Household Sector: Theory and Empirical 

Evidence,” Journal of Transport Economics and Policy, 24:2 (1990), 119-137; and David L. Greene, James R. Kahn, 

and Robert C. Gibson, “Fuel Economy Rebound Effect for Household Vehicles,” The Energy Journal, 20:3 (1999), 

1-21. 

164 In the most recent light truck CAFE rulemaking, NHTSA chose not to preference the Small and Van Dender 

study over other published estimates of the value of the rebound effect, stating that since it “remains an unpublished 

working paper that has not been subjected to formal peer review, ...the agency does not yet consider the estimates it 

provides to have the same credibility as the published and widely-cited estimates it relied upon.” See 71 FR 17633 

(Apr. 6, 2006). The study has subsequently been published and peer-reviewed, so NHTSA is now prepared to 

“consider it in developing its own estimate of the rebound effect for use in subsequent CAFE rulemakings.” 
VIII-9

published fuel economy ratings for different models. In analyzing the fuel savings from 

alternative passenger car and light truck CAFE standards, the agency adjusts the actual fuel 

economy performance of each passenger car and light truck model downward from its rated 

value to reflect the expected size of this on-road fuel economy “gap.” In December 2006, EPA 

adopted changes to its regulations on fuel economy labeling, which were intended to bring 

vehicles’ rated fuel economy levels closer to their actual on-road fuel economy levels.165 

Supplemental analysis reported by EPA as part of its Final Rule indicates that actual on-road fuel 

economy for light-duty vehicles averages 20 percent lower than published fuel economy 

levels.166 For example, if the overall EPA fuel economy rating of a light truck is 20 mpg, the onroad fuel economy actually achieved by a typical driver of that vehicle is expected to be 16 mpg 

(20*.80). The agency has employed EPA’s revised estimate of this on-road fuel economy gap in 

its analysis of the fuel savings resulting from alternative CAFE standards for MY 2011-2018 

passenger cars and MY 2012-18 light trucks. 

Benefits from Fuel Savings 

The main source of economic benefits from a fuel economy standard is the value of the resulting 

fuel savings over the lifetimes of vehicles that are required to comply with the stricter standards. 

These fuel savings for each scenario are measured by the difference between the adjusted 

baseline fuel economy for each model year and the fuel economy levels corresponding to that 

alternative. The sum of these annual fuel savings over each calendar year that a vehicle remains 

in service represents the cumulative fuel savings resulting from applying the alternative to 

vehicles produced during that model year. 

As previously noted, actual fuel economy levels achieved by vehicles in on-road driving fall 

significantly short of their levels measured under the laboratory-like test conditions used by EPA 

to establish its published fuel economy ratings for different models. In analyzing the fuel 

savings from alternative passenger car and light truck CAFE standards, the agency adjusts the 

actual fuel economy performance of each passenger car and light truck model downward from its 

rated value to reflect the expected size of this on-road fuel economy “gap.” In December 2006, 

EPA adopted changes to its regulations on fuel economy labeling, which were intended to bring 

vehicles’ rated fuel economy levels closer to their actual on-road fuel economy levels.167 

Supplemental analysis reported by EPA as part of its Final Rule indicates that actual on-road fuel 

economy for light-duty vehicles averages 20 percent lower than published fuel economy 

 

165 EPA, Fuel Economy Labeling of Motor Vehicles: Revisions To Improve Calculation of Fuel Economy Estimates; Final Rule, 40 CFR Parts 

86 and 600, Federal Register, December 27, 2006, pp. 77872-77969, http://www.epa.gov/fedrgstr/EPA-AIR/2006/December/Day27/a9749.pdf. 

166 EPA, Final Technical Support Document: Fuel Economy Labeling of Motor Vehicle Revisions to Improve 

Calculation of Fuel Economy Estimates, Office of Transportation and Air Quality EPA420-R-06-017 December 

2006, Chapter II, http://www.epa.gov/fueleconomy/420r06017.pdf. 167 EPA, Fuel Economy Labeling of Motor Vehicles: Revisions To Improve Calculation of Fuel Economy Estimates; Final Rule, 40 CFR Parts 

86 and 600, Federal Register, December 27, 2006, pp. 77872-77969, http://www.epa.gov/fedrgstr/EPA-AIR/2006/December/Day27/a9749.pdf. 
VIII-10

levels.168 The agency has employed EPA’s revised estimate of this on-road fuel economy gap in 

its analysis of the fuel savings resulting from alternative CAFE standards for MY 2011-2018 

passenger cars and MY 2012-18 light trucks. 

The number of light vehicles manufactured during each model year that remains in service 

during each subsequent calendar year is estimated by multiplying the estimated proportions of 

vehicles expected to survive to each age up to 26 years for passenger cars (Table VIII-2a) and 36 

years for light trucks (Table VIII-2b) by the number of cars and light trucks forecast to be 

produced during each year. These “survival rates,” which are estimated from experience with 

recent model-year vehicles, are slightly different than the survival rates used in past NHTSA 

analyses since they reflect recent increases in durability and usage of more recent passenger car 

and light truck models.169 Updated estimates of average annual miles driven by vehicle age were 

developed from the Federal Highway Administration’s 2001 National Household Transportation 

Survey, and these also differ from the estimates of annual mileage employed in past NHTSA 

analyses.170 The total number of miles driven by vehicles of a single model year during each 

year of its life span in the fleet in effect is estimated by multiplying these age-specific estimates 

of annual miles driven per vehicle by the number of vehicles projected to remain in service at 

each age. 

Table VIII-2a and VIII-2b provide the new schedules of vehicle miles traveled and survivability 

based on updated analyses performed by NHTSA. These were developed from registration data 

for 1977 through 2003, and from a 2001 survey of household vehicle use. In this analysis, the 

maximum vehicle age was defined as the age when the number remaining in service has declined 

to approximately two percent of the vehicles originally produced. Based on and examination of 

recent registration data for older model years, typical maximum ages appear to be 26 years for 

passenger cars and 36 years for light trucks. Using the 36-year estimate of the maximum 

lifetimes of light trucks results in survival-weighted or “expected” lifetime mileage of 190,066 

miles. Fuel savings and other benefits resulting from higher light truck CAFE standards are 

calculated over this expected 36 year lifetime and total mileage. In contrast, NHTSA’s previous 

estimate of lifetime VMT in the 2006 final rule was 179,954 miles over a 36-year lifetime for 

light trucks. The resulting survival-weighted mileage over the 26-year maximum lifetime of 

passenger cars is 161,847 miles, and fuel savings and other benefits resulting from higher 

passenger car CAFE standards are calculated over this 26-year lifetime and total mileage. It 

should be noted, however, that survival-weighted VMT is extremely low (less than 1,000 miles 

per year) after age 20 for cars and age 25 for light trucks, and thus has little impact on lifetime 

fuel savings or other benefits from higher fuel economy, particularly after discounting those 

benefits to their present values. 

 

168 EPA, Final Technical Support Document: Fuel Economy Labeling of Motor Vehicle Revisions to Improve 

Calculation of Fuel Economy Estimates, Office of Transportation and Air Quality EPA420-R-06-017 December 

2006, Chapter II, http://www.epa.gov/fueleconomy/420r06017.pdf. 169 The survival rates were calculated from R.L. Polk, National Vehicle Population Profile, 1977-2003; see NHTSA, 

“Vehicle Survivability and Travel Mileage Schedules,” Office of Regulatory Analysis and Evaluation, NCSA, 

January 2006, pp. 9-11, Docket No. 22223-2218. 170 See also NHTSA, “Vehicle Survivability and Travel Mileage Schedules,” Office of Regulatory Analysis and 

Evaluation, January 2006, pp. 15-17. 
VIII-11

The primary source of data for determining vehicles in operation is the National Vehicle 

Population Profile (NVPP) compiled by R.L. Polk and Company. The NVPP is an annual 

census, as of July 1 of each year, of passenger cars and light trucks registered for on-road 

operation in the United States. NVPP registration data was used from vehicle model years 1977 

to 2003. Survival rates were averaged for the five most recent model years for vehicles up to 20 

years old, and regression models were fitted to these data to develop smooth relationships 

between age and the proportion of cars or light trucks surviving to that age. The survival rates 

predicted by these models are used to develop the estimates of annual mileage and fuel 

consumption used to calculate fuel savings and other impacts of higher fuel economy. 

The 2001 National Household Travel Survey (NHTS) sponsored by the Federal Highway 

Administration, Bureau of Transportation Statistics, and the National Highway Traffic Safety 

Administration attempted to develop up-to-date information on household vehicle ownership and 

use. The NHTS is the integration of two previous national travel surveys: the Federal Highway 

Administration-sponsored Nationwide Personal Transportation Survey (NPTS) and the Bureau 

of Transportation Statistics-sponsored American Travel Survey (ATS).171 The 2001 NHTS was 

the source of updated information on annual miles driven by age for passenger cars and light 

trucks. 

Finally, it should be noted that the estimates of average annual miles driven by passenger cars and 

light trucks, while new for NHTSA, are based on data collected during 2001-2002, and reflect the 

historically low gasoline prices that prevailed at the time the survey was conducted. To account for 

the effect on vehicle use of subsequent increases in fuel prices, the estimates of annual vehicle use 

derived from the NHTS are adjusted to reflect projected future gasoline prices using the rebound 

effect, which is discussed in detail later in this chapter. Two factors affect the cost of gasoline per 

mile driven - fuel prices per gallon, and fuel economy in miles-per-gallon. Because the intensity of 

vehicle use depends partly on the cost per mile of driving, the estimates of vehicle use developed from 

NHTS data reflect both fuel prices and fuel economy levels that prevailed during 2001 and 2002, when 

the survey was conducted. In analyzing the final rule, the agency adjusted the annual usage estimates 

derived from the NHTS data to reflect the effect of the higher EIA fuel prices that are forecast over the 

covered vehicles’ expected lifetimes, which exceed those that existed during 2001-2002. 

Specifically, the adjustment accounted for the difference between the average price per gallon of fuel 

forecast over the expected lifetimes of model year 2011-2015 passenger cars and light trucks and the 

average price that prevailed during 2000 and 2001. When expressed in percentage terms, this 

difference was assumed to represent the percent increase in fuel cost per mile driven between the time 

the survey was conducted and the time period when model year 2011-2015 passenger cars and light 

trucks would be in service. 

The same elasticity of annual vehicle use with respect to fuel cost per mile that was used to estimate 

the increase in vehicle use resulting from improved fuel economy (see detailed discussion of the 

“rebound effect” earlier in this chapter), assumed to be –0.15, was applied to this percent difference to 

adjust the estimates of vehicle use derived from the survey to reflect the effect of higher future fuel 

prices. In contrast, this adjustment reduces model year 2011-2015 passenger cars’ and light trucks’ 

average annual usage at each age to account for the fact that fuel cost per mile driven is expected to be 

 

171 For details on survey coverage and procedures, see http://nhts.ornl.gov/quickStart.shtml. 
VIII-12

higher throughout their expected lifetimes than at the time the NHTS was conducted. The results of 

this adjustment are shown in Table VIII-2c for passenger cars and in Table VIII-2d for light trucks. 

The unadjusted average lifetime mileage is estimated to be 161,847 for passenger cars and 190,066 for 

light trucks. After adjusting for the rebound effect, the average lifetime mileage is estimated to be 

152,274 for passenger cars and 178,824 for light trucks. 
VIII-13

Table VIII-2a 

Survival Rates and Unadjusted Annual Vehicle-Miles Traveled (VMT) 

by Age for Passenger Cars 

Vehicle Age 

Estimated 

Survivability

(1977 to 2002 NVPP)

Estimated VMT 

(2001 NHTS) 

Weighted Yearly 

Travel Miles 

1 0.9950 14,231 14,160 

2 0.9900 13,961 13,821 

3 0.9831 13,669 13,438 

4 0.9731 13,357 12,998 

5 0.9593 13,028 12,497 

6 0.9413 12,683 11,938 

7 0.9188 12,325 11,324 

8 0.8918 11,956 10,662 

9 0.5604 11,578 9,961 

10 0.8252 11,193 9,237 

11 0.7866 10,804 8,499 

12 0.7170 10,413 7,466 

13 0.6125 10,022 6,138 

14 0.5094 9,633 4,907 

15 0.4142 9,249 3,831 

16 0.3308 8,871 2,934 

17 0.2604 8,502 2,214 

18 0.2028 8,144 1,652 

19 0.1565 7,799 1,220 

20 0.1200 7,469 896 

21 0.0916 7,157 656 

22 0.0696 6,866 478 

23 0.0527 6,596 348 

24 0.0399 6,350 253 

25 0.0301 6,131 185 

26 0.0227 5,940 135 

 

Estimated Passenger Car Lifetime VMT 161,847 
VIII-14

Table VIII-2b 

Survival Rates and Unadjusted Annual Vehicle-Miles Traveled (VMT) 

by Age for Light Trucks 

Vehicle Age 

Estimated 

Survivability

(1977 to 2002 NVPP)

Estimated VMT 

(2001 NHTS) 

Weighted Yearly 

Travel Miles 

1 0.9950 16,085 16,004 

2 0.9741 15,782 15,374 

3 0.9603 15,442 14,829 

4 0.9420 15,069 14,195 

5 0.9190 14,667 13,479 

6 0.8913 14,239 12,691 

7 0.8590 13,790 11,845 

8 0.8226 13,323 10,960 

9 0.7827 12,844 10,053 

10 0.7401 12,356 9,145 

11 0.6956 11,863 8,252 

12 0.6501 11,369 7,391 

13 0.6042 10,879 6,573 

14 0.5517 10,396 5,735 

15 0.5009 9,924 4,971 

16 0.4522 9,468 4,281 

17 0.4062 9,032 3,669 

18 0.3633 8,619 3,131 

19 0.3236 8,234 2,665 

20 0.2873 7,881 2,264 

21 0.2542 7,565 1,923 

22 0.2244 7,288 1,635 

23 0.1975 7,055 1,393 

24 0.1735 6,871 1,192 

25 0.1522 6,739 1,026 

26 0.1332 6,663 887 

27 0.1165 6,648 774 

28 0.1017 6,648 676 

29 0.0887 6,648 590 

30 0.0773 6,648 514 

31 0.0673 6,648 447 

32 0.0586 6,648 390 

33 0.0509 6,648 338 

34 0.0443 6,648 294 

35 0.0385 6,648 256 

36 0.0334 6,648 222 

 

Estimated Lifetime Light Truck VMT 190,066 
VIII-15

Table VIII-2c 

Survival Rates and Adjusted Annual Vehicle-Miles Traveled (VMT) 

by Age for Passenger Cars 

Vehicle Age Estimated 

Survivability Adjusted VMT Weighted Yearly Travel Miles 

1 0.9950 13,389 13,322 

2 0.9900 13,135 13,004 

3 0.9831 12,860 12,643 

4 0.9731 12,567 12,229 

5 0.9593 12,257 11,758 

6 0.9413 11,933 11,232 

7 0.9188 11,596 10,654 

8 0.8918 11,248 10,031 

9 0.5604 10,893 9,372 

10 0.8252 10,531 8,690 

11 0.7866 10,165 7,996 

12 0.7170 9,797 7,025 

13 0.6125 9,429 5,775 

14 0.5094 9,063 4,617 

15 0.4142 8,702 3,604 

16 0.3308 8,346 2,761 

17 0.2604 7,999 2,083 

18 0.2028 7,662 1,554 

19 0.1565 7,337 1,148 

20 0.1200 7,028 843 

21 0.0916 6,734 617 

22 0.0696 6,459 450 

23 0.0527 6,206 327 

24 0.0399 5,974 238 

25 0.0301 5,768 174 

26 0.0227 5,589 127 

Adjusted Lifetime Passenger Car VMT 152,274 
VIII-16

Table VIII-2d 

Survival Rates and Adjusted Annual Vehicle-Miles Traveled (VMT) 

by Age for Light Trucks 

Vehicle Age Estimated 

Survivability Adjusted VMT Weighted Yearly Travel Miles 

1 0.9950 15,133 15,058 

2 0.9741 14,849 14,464 

3 0.9603 14,529 13,952 

4 0.9420 14,178 13,356 

5 0.9190 13,799 12,681 

6 0.8913 13,396 11,940 

7 0.8590 12,974 11,145 

8 0.8226 12,535 10,312 

9 0.7827 12,084 9,458 

10 0.7401 11,625 8,604 

11 0.6956 11,161 7,764 

12 0.6501 10,697 6,954 

13 0.6042 10,235 6,184 

14 0.5517 9,781 5,396 

15 0.5009 9,337 4,677 

16 0.4522 8,908 4,028 

17 0.4062 8,498 3,452 

18 0.3633 8,109 2,946 

19 0.3236 7,747 2,507 

20 0.2873 7,415 2,130 

21 0.2542 7,117 1,809 

22 0.2244 6,857 1,539 

23 0.1975 6,638 1,311 

24 0.1735 6,464 1,122 

25 0.1522 6,340 965 

26 0.1332 6,269 835 

27 0.1165 6,254 729 

28 0.1017 6,254 636 

29 0.0887 6,254 555 

30 0.0773 6,254 483 

31 0.0673 6,254 421 

32 0.0586 6,254 367 

33 0.0509 6,254 318 

34 0.0443 6,254 277 

35 0.0385 6,254 241 

36 0.0334 6,254 209 

 

Adjusted Lifetime Light Truck VMT 178,824 
VIII-17

In interpreting the survivability and annual mileage estimates reported in Tables VIII-2a through 

VIII-2d, it is important to understand that vehicles are considered to be of age 1 during the 

calendar year that coincides with their model year Thus for example, model year 2010 vehicles 

will be considered to be of age 1 during calendar year 2010. This convention is used in order to 

account for the fact that vehicles produced during a model year typical are first offered for sale in 

June through September of the preceding calendar year (for example, sales of a model year 

typically begin in June through September of the previous calendar year, depending on 

manufacturer). Thus virtually all of the vehicles produced during a model year will be in use for 

some or all of the calendar year coinciding with their model year, and they are considered to be 

of age 1 during that year.172 As an illustration, virtually the entire production of model year 2008 

vehicles will have been sold and placed in service by the end of calendar year 2008, so model 

year 2008 vehicles are defined to be of age 1 during calendar year 2008.Model year 2008 

vehicles are subsequently defined to be of age 2 during calendar year 2009, age 3 during 

calendar year 2010, and so on, until they reach their maximum age of 36 years in calendar year 

2043 (2008 + 35 = 2043). 

To determine the impact of improved CAFE standards, fuel consumption is calculated using both 

current and revised CAFE levels. The difference between these estimates represents the net 

savings from increased CAFE standards. With the current CAFE standard assumed to remain in 

effect, total fuel consumption by each model year’s vehicles during each calendar year they 

remain in service is calculated by dividing the total number of miles they are driven during that 

year by the average on-road fuel economy level they would achieve under the higher of either the 

manufacturer-specific standard or their production plans. With the final rule in effect, total fuel 

consumption by each model year’s vehicles during each future calendar year is calculated by 

dividing the total number of miles they are driven by the higher on-road fuel economy level 

associated with that stricter CAFE standard. The total number of miles that vehicles are driven 

each year is different under the final rule than with the current standards remaining in effect as a 

result of the fuel economy “rebound effect,” which is discussed in detail later in this chapter. 

The economic benefits to vehicle owners that result from future fuel savings are valued in this 

analysis over the complete expected lifetimes of the vehicles affected by the final rule. This 

reflects the assumption that while the purchaser and first owner of a new vehicle might not 

realize the full lifetime benefits of improved fuel economy, subsequent owners of that same 

vehicle will continue to experience the resulting fuel savings until the vehicle is retired from 

service. It is important to note, however, that not all vehicles produced during a model year 

remain in service for the complete lifetime (26-year for passenger cars or 36 –year for light 

trucks) of each model year assumed in this analysis. Due to the pattern of vehicle retirement 

over this period, the expected or average lifetime of a representative vehicle is approximately 

half of that figure. 

CAFE’s most immediate impacts are on individual consumers, but regulating fuel economy also 

has a broader societal impact that must be considered. The agency believes that CAFE standards 

should reflect the true economic value of resources that are saved when less fuel is produced and 

 

172 One complication arises because registration data are typically collected for July 1 of each calendar year, so not 

all vehicles produced during a model year will appear in registration data until the calendar year when they have 

reached age 2 (and sometimes age 3) under this convention. 
VIII-18

consumed, higher vehicle prices, and, to the extent possible, any externalities that impact the 

broader society. Consumers’ perceptions of these values may differ from their actual impacts, 

but they will nonetheless experience the full value of actual fuel savings just as they will pay the 

full increased cost when the vehicle is purchased. 

Moreover, the first and any subsequent owners of a vehicle will together realize these savings 

throughout its entire on-road lifetime. While a vehicle’s buyer may only experience fuel savings 

for the limited time he or she typically owns that vehicle, any subsequent purchasers and owners 

of that used vehicle will continue to experience the fuel savings resulting from its higher fuel 

economy throughout the remainder of its useful life. The agency restricts its analysis of the sales 

impacts of higher new vehicle prices to the length of time the buyers of new vehicles typically 

own the vehicles they purchase, under the assumption that their purchase decisions will be 

influenced only by the benefits they receive during the time they expect to own the vehicles they 

purchase new. The agency estimates the length of this period using the average term of new car 

loans, which has recently averaged almost exactly 5 years.173 However, the agency believes that 

the value of fuel savings resulting from more efficient operation over the entire lifetime of 

vehicles should be reflected in its analysis of the societal impacts that will determine fuel 

economy standards. 

The economic value of fuel savings resulting from the final rule is estimated by applying the 

forecast of future fuel prices from the Reference Case of the Energy Information 

Administration’s Annual Energy Outlook 2008 Early Release to each future year’s estimated 

fuel savings.174 (The uncertainty analysis reported in Chapter X uses fuel price forecasts from 

the High and Low Oil Price Scenarios included in AEO 2007 to examine the effects a range of 

possible fuel price scenarios, since High and Low Oil Price Scenario forecasts for AEO 2008 

were not available at the time this analysis was conducted.) The AEO 2008 Early Release 

forecast of future fuel prices, which is reported in Table VIII-3, represents retail prices per gallon 

of fuel, which including Federal, State, and any applicable local taxes. While the retail price of 

fuel is the proper measure for valuing fuel savings from the perspective of vehicle owners, two 

adjustments to the retail price are necessary in order to reflect the economic value of fuel savings 

to society as a whole. 

First, Federal and State taxes are excluded from the social value of fuel savings because these do 

not reflect costs of resources used in fuel production, and thus do not reflect resource savings 

that would result from reducing fuel consumption. Instead, fuel taxes simply represent resources 

that are transferred from one segment of the population to another. Any reduction in State and 

Federal fuel tax payments by consumers will reduce government revenues by the same amount, 

thus ultimately reducing the value of government-financed services by approximately that same 

amount. The benefit derived from lower taxes to individuals is thus likely to be offset exactly by 

a reduction in the value of services provided to society. 

 

173 This estimate is derived from Federal Reserve Board, Federal Reserve Statistical Release G. 19: Consumer 

Credit, November 7, 2007, http://www.federalreserve.gov/releases/g19/Current/. 174 U.S. Department of Energy, Energy Information Administration, Annual Energy Outlook 2008 Early Release, 

Reference Case Table 12, http://www.eia.doe.gov/oiaf/aeo/excel/aeotab_12.xls. 
VIII-19

Second, the economic cost of externalities generated by imports and consumption of petroleum 

products will be reduced in proportion to gasoline savings resulting from the final rule. The 

estimated economic value of these externalities is converted into its per-gallon equivalent and 

added to the pre-tax price of gasoline in order to measure this additional benefit to society for 

each gallon of fuel saved. This also allows the magnitude of these externalities to be easily 

compared to the value of the resources saved from reduced fuel production and use, which 

represents the most important component of the social benefits from saving gasoline. A 

discussion of these externality values is included in the next section of this chapter 

Table VIII-3 illustrates the adjustment of forecast retail fuel prices to remove the value of fuel 

taxes and add the value of economic externalities from petroleum imports and use. The 

derivation of the estimated value of reduced economic externalities from petroleum use shown in 

the table is explained in detail in the following section. While the Reference Case fuel price 

forecasts reported in AEO 2008 Early Release extend through 2030, the agency’s analysis of the 

value of fuel savings over the 26-year maximum lifetimes of MY 2011-15 passenger cars and 

36-year maximum lifetimes MY 2011-15 light trucks requires forecasts extending through 

calendar year 2050. The agency assumes that retail fuel prices will remain at the 2030 forecast 

values reported in the AEO 2008 Reference Case forecast over the period from 2030 through 

2052 (in constant-dollar terms). As Table VIII-3 shows, the projected retail price of gasoline 

expressed in 2006 dollars varies over the forecast period, declining from $2.69 in 2008 to $2.20 

in 2016, and then increasing to $2.49 by 2030 and as assumed previously, remaining at that level 

through 2052. 

Since gasoline taxes are a transfer payment and not a societal cost, the value of gasoline taxes is 

subtracted from the estimated gasoline price to estimate the value to society of saving gasoline. 

The agency has updated its estimates of gasoline taxes, using updated State tax rates reported for 

January 1, 2006. Expressed in 2006 dollars, Federal gasoline taxes are currently $0.172, while 

State and local gasoline taxes together average $0.262 per gallon, for a total tax burden of $0.434 

per gallon. 

Following the assumptions used by EIA in its National Energy Modeling System (NEMS), state 

and local gasoline taxes are assumed to keep pace with inflation in nominal terms, and thus to 

remain constant when expressed in constant 2006 dollars. In contrast, federal gasoline taxes are 

assumed to remain unchanged in nominal terms, and thus to decline throughout the forecast 

period when expressed in constant 2006 dollars. These differing assumptions about the likely 

future behavior of federal and state/local fuel taxes are consistent with recent historical 

experience, and reflect the fact that Federal motor fuel taxes and most State taxes are specified 

on a cents-per-gallon basis (some State taxes are levied as a percentage of the wholesale price of 

fuel), and typically require legislation to change. 

 

Actual fuel economy levels achieved by light-duty vehicles in on-road driving fall somewhat 

short of their levels measured under the laboratory-like test conditions used by EPA to establish 

its published fuel economy ratings for different models. In analyzing the fuel savings from 

alternative CAFE standards, NHTSA has previously adjusted the actual fuel economy 

performance of each light truck model downward from its rated value to reflect the expected size 

of this on-road fuel economy “gap.” On December 27, 2006, EPA adopted changes to its 
VIII-20

regulations on fuel economy labeling, which were intended to bring vehicles’ rated fuel economy 

levels closer to their actual on-road fuel economy levels.175

In its Final Rule, EPA estimated that actual on-road fuel economy for light-duty vehicles 

averages 20 percent lower than published fuel economy levels. For example, if the overall EPA 

fuel economy rating of a light truck is 20 mpg, the on-road fuel economy actually achieved by a 

typical driver of that vehicle is expected to be 16 mpg (20*.80). NHTSA has employed EPA’s 

revised estimate of this on-road fuel economy gap in this analysis of the fuel savings resulting 

from alternative CAFE standards proposed in this rulemaking. 

Table VIII-3 

Adjustment of Forecast Retail Gasoline Price to Reflect Social Value of Fuel Savings 

Year 

AE0 2008 Forecast of 

Retail Gasoline Price 

(2006 $/gallon) 

Estimated Federal 

and State Taxes 

(2006 $/gallon) 

Forecast Gasoline Price 

Excluding Taxes 

(2006 $/gallon) 

Forecast Gasoline Price 

Including Externalities

(2006 $/gallon) 

2011 $2.553 $0.420 $2.133 $2.428 

2012 $2.477 $0.416 $2.061 $2.356 

2013 $2.405 $0.412 $1.993 $2.288 

2014 $2.389 $0.409 $1.980 $2.275 

2015 $2.316 $0.405 $1.911 $2.206 

2016 $2.255 $0.402 $1.853 $2.148 

2017 $2.267 $0.399 $1.868 $2.163 

2018 $2.293 $0.395 $1.898 $2.193 

2019 $2.362 $0.392 $1.970 $2.265 

2020 $2.420 $0.388 $2.032 $2.327 

2021 $2.386 $0.385 $2.001 $2.296 

2022 $2.406 $0.381 $2.025 $2.320 

2023 $2.414 $0.378 $2.036 $2.331 

2024 $2.409 $0.374 $.2.035 $2.330 

2025 $2.425 $0.371 $2.054 $2.349 

2026 $2.438 $0.371 $2.067 $2.362 

2027 $2.451 $0.371 $2.080 $2.375 

2028 $2.474 $0.371 $2.103 $2.398 

2029 $2.498 $0.371 $2.127 $2.422 

2030-2052 $2.514 $0.371 $2.143 $2.438 

 

175 71 FR 77871 (Dec. 27, 2006). 
VIII-21

Other Economic Benefits from Reducing Petroleum Use 

The agency believes that assessing the economic case for increasing the stringency of fuel 

economy standards requires a comprehensive analysis of the resulting benefits and costs to the 

U.S economy, rather than simply comparing the direct costs associated with petroleum use and 

fuel production to current fuel taxes. The benefits of more stringent fuel economy standards 

include the market value of the savings in resources from producing less fuel, together with the 

resulting reductions in the costs of economic externalities associated with petroleum 

consumption, and of environmental externalities caused by fuel consumption and production. 

Environmental externalities include adverse health impacts associated with criteria pollutants and 

environmental damage associated with greenhouse gases. The costs imposed on the U.S. 

economy by more stringent fuel economy regulation include those costs for manufacturing more 

fuel-efficient vehicles, as well as the increased external costs of congestion, crashes, noise and 

pollution from added driving caused by the rebound effect. 

Vehicle buyers value improved fuel economy using retail fuel prices and miles per gallon, but 

may consider fuel savings only over the time they expect to own a vehicle, while the value to the 

U.S. economy of saving fuel is measured by its pre-tax price, and includes fuel savings over the 

entire lifetime of vehicles. Thus, it cannot simply be assumed that the interaction of 

manufacturers’ costs and vehicle buyers’ demands in the private marketplace will determine 

optimal fuel economy levels, and that these levels should only be adjusted by Federal regulation 

if the external costs of fuel production and use exceed current fuel taxes. 

The Agency’s analysis estimates the value of each category of benefits and costs separately, and 

it compares the total benefits resulting from each alternative level to its total costs in order to 

assess its desirability. This more complete accounting of benefits and costs to the U.S. economy 

from reducing fuel use is necessary to assess the case for fuel economy regulation generally, and 

for increasing the stringency of the current passenger car and light truck fuel economy standards 

in particular. 

U.S. consumption and imports of petroleum products also impose costs on the domestic 

economy that are not reflected in the market price for crude petroleum, or in the prices paid by 

consumers of petroleum products such as gasoline. These costs include (1) higher prices for 

petroleum products resulting from the effect of U.S. oil import demand on the world oil price; (2) 

the risk of disruptions to the U.S. economy caused by sudden reductions in the supply of 

imported oil to the U.S.; and (3) expenses for maintaining a U.S. military presence to secure 

imported oil supplies from unstable regions, and for maintaining the strategic petroleum reserve 

(SPR) to cushion against resulting price increases. Higher U.S. imports of crude oil or refined 

petroleum products raise the magnitude of these external economic costs, thus increasing the true 

economic cost of supplying transportation fuels above the resource costs of producing them. 

Conversely, reducing U.S. imports of crude petroleum or refined fuels or reducing fuel 

consumption can reduce these external costs. Any reduction in their total value that results from 

improved vehicle fuel economy represents an economic benefit of raising fuel economy 

standards in addition to the value of fuel savings and emissions reductions itself. 
VIII-22

Demand Costs

Increased U.S. oil imports can impose higher costs on all purchasers of petroleum products, 

because the U.S. is a sufficiently large purchaser of foreign oil supplies that changes in U.S. 

demand can affect the world price. The effect of U.S. petroleum imports on world oil prices is 

determined by the degree of OPEC monopoly power over global oil supplies, and the degree of 

monopsony power over world oil demand exerted by the U.S. The combination of these two 

factors means that increases in domestic demand for petroleum products that are met through 

higher oil imports can cause the price of oil in the world market to rise, which imposes economic 

costs on all other purchasers in the global petroleum market in excess of the higher prices paid 

by U.S. consumers.176 Conversely, reducing U.S. oil imports can lower the world petroleum 

price, and thus generate benefits to other oil purchasers by reducing these “monopsony costs.” 

Although the degree of current OPEC monopoly power is subject to considerable debate, the 

consensus appears to be that OPEC remains able to exercise some degree of control over the 

response of world oil supplies to variation in world oil prices, so that the world oil market does 

not behave competitively.177 The extent of U.S. monopsony power is determined by a complex 

set of factors including the relative importance of U.S. imports in the world oil market, and the 

sensitivity of petroleum supply and demand to its world price among other participants in the 

international oil market. Most evidence appears to suggest that variation in U.S. demand for 

imported petroleum continues to exert some influence on world oil prices, although this 

influence appears to be limited.178 

In analyzing benefits from its recent actions to increase light truck CAFE standards for model 

years 2005-07 and 2008-11, NHTSA relied on a 1997 study by Oak Ridge National Laboratories 

(ORNL) to estimate the value of reduced economic externalities from petroleum consumption 

and imports.179 More recently, ORNL updated its estimates of the value of these externalities, 

using the analytic framework developed in its original 1997 study in conjunction with recent 

estimates of the variables and parameters that determine their value. 180 These include world oil 

prices, current and anticipated future levels of OPEC petroleum production, U.S. oil import 

 

176 For example, if the U.S. imports 10 million barrels of petroleum per day at a world oil price of $80 per barrel, its 

total daily import bill is $800 million. If increasing imports to 11 million barrels per day causes the world oil price 

to rise to $81 per barrel, the daily U.S. import bill rises to $891 million. The resulting increase of $91 million per 

day ($891 minus $800 million) is attributable to increasing daily imports by only 1 million barrels. This means that 

the incremental cost of importing each additional barrel is $91, or $10 more than the newly-increased world price of 

$81 per barrel. This additional $10 per barrel represents a cost imposed on all other purchasers in the global 

petroleum market by U.S. buyers, in excess of the price they pay to obtain those additional imports. 

177 For a summary see Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An 

Assessment of Benefits and Costs, ORNL-6851, Oak Ridge National Laboratory, November 1, 1997, at 17. 

Available at http://dmses.dot.gov/docimages/pdf93/343894_web.pdf (last accessed Dec. 2, 2007). 178 Id., at 18-19. 

179 Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An Assessment of Benefits 

and Costs, ORNL-6851, Oak Ridge National Laboratory, November 1, 1997. Available at

http://dmses.dot.gov/docimages/pdf93/343894_web.pdf (last accessed Dec. 2, 2007). 

180 Leiby, Paul N. "Estimating the Energy Security Benefits of Reduced U.S. Oil Imports," Oak Ridge National 

Laboratory, ORNL/TM-2007/028, Revised July 23, 2007. Available at http://pzl1.ed.ornl.gov/energysecurity.html 

(click on link below “Oil Imports Costs and Benefits”) (last accessed Sept. 10, 2007). 
VIII-23

levels, the estimated responsiveness of oil supplies and demands to prices in different regions of 

the world, and the likelihood of oil supply disruptions. ORNL’s prepared its updated estimates 

of oil import externalities were for use by EPA in evaluating the benefits of reductions in U.S. oil 

consumption and imports expected to result from its recently-issued Renewable Fuel Standard 

Rule of 2007 (RFS)181. 

The updated ORNL study was subjected to a detailed peer review and its estimates of the value 

of oil import externalities were subsequently revised to reflect their comments and 

recommendations. 182 Specifically, reviewers recommended that ORNL increase its estimates of 

the sensitivity of oil supply by non-OPEC producers and oil demand by nations other than the 

U.S. to changes in the world oil price, as well as reduce its estimate of the sensitivity of U.S. 

gross domestic product (GDP) to potential sudden increases in world oil prices. After making 

the revisions recommended by peer reviewers, ORNL’s updated estimates of the monopsony 

cost associated with U.S. oil imports range from $5.22 to $9.68 per barrel, with a most likely 

estimate of $7.41 per barrel. These estimates imply that each gallon of fuel saved as a result of 

adopting higher CAFE standards will reduce the monopsony costs of U.S. oil imports by $0.124 

to $0.230 per gallon, with the actual value most likely to be $0.176 per gallon saved. This 

represents an economic benefit in addition to the value of savings in fuel production costs that 

would result from improving fuel economy. 

Disruption and Adjustment Costs

The second component of external economic costs imposed by U.S. petroleum imports arises 

partly because an increase in oil prices triggered by a disruption in the supply of imported oil 

reduces the level of output that the U.S. economy can produce. The reduction in potential U.S. 

economic output depends on the extent and duration of the increases in petroleum product prices 

that result from a disruption in the supply of imported oil, as well as on whether and how rapidly 

these prices return to pre-disruption levels. Even if prices for imported oil return completely to 

their original levels, however, economic output will be at least temporarily reduced from the 

level that would have been possible without a disruption in oil supplies. 

Because supply disruptions and resulting price increases tend to occur suddenly rather than 

gradually, they can also impose costs on businesses and households for adjusting their use of 

petroleum products more rapidly than if the same price increase had occurred gradually over 

time. These adjustments impose costs because they temporarily reduce economic output even 

below the level that would ultimately be reached once the U.S. economy completely adapted to 

higher petroleum prices. The additional costs to businesses and households reflect their inability 

to adjust prices, output levels, and their use of energy and other resources quickly and smoothly 

in response to rapid changes in prices for petroleum products. 

Since future disruptions in foreign oil supplies are an uncertain prospect, each of these disruption 

costs must be adjusted by the probability that the supply of imported oil to the U.S. will actually 

be disrupted. The “expected value” of these costs – the product of the probability that an oil 

import disruption will occur and the costs of reduced economic output and abrupt adjustment to 

 

181 Federal Register Vol.72, #83, May 1, 2007 pp.23,900-24,014 

182 Peer Review Report Summary: Estimating the Energy Security Benefits of Reduced U.S. Oil Imports, 

ICF, Inc., September 2007. 
VIII-24

sharply higher petroleum prices – is the appropriate measure of their magnitude. Any reduction 

in these expected disruption costs resulting from a measure that lowers U.S. oil imports 

represents an additional economic benefit beyond the direct value of savings from reduced 

purchases of petroleum products. 

While the vulnerability of the U.S. economy to oil price shocks is widely thought to depend on 

total petroleum consumption rather than on the level of oil imports, variation in imports is still 

likely to have some effect on the magnitude of price increases resulting from a disruption of 

import supply. In addition, changing the quantity of petroleum imported into the U.S. may also 

affect the probability that such a disruption will occur. If either the size of the likely price 

increase or the probability that U.S. oil supplies will be disrupted is affected by oil imports, the 

expected value of the costs from a supply disruption will also depend on the level of imports. 

Businesses and households use a variety of market mechanisms, including oil futures markets, 

energy conservation measures, and technologies that permit rapid fuel switching to “insure” 

against higher petroleum prices and reduce their costs for adjusting to sudden price increases. 

While the availability of these market mechanisms has likely reduced the potential costs of 

disruptions to the supply of imported oil, consumers of petroleum products are unlikely to take 

account of costs they impose on others, so these costs are probably not reflected in the price of 

imported oil. Thus changes in oil import levels probably continue to affect the expected cost to 

the U.S. economy from potential oil supply disruptions, although this component of oil import 

costs is likely to be significantly smaller than estimated by studies conducted in the wake of the 

oil supply disruptions during the 1970s. 

ORNL’s updated and revised estimates of the increase in the expected costs associated with oil 

supply disruptions to the U.S. and the resulting rapid increase in prices for petroleum products 

amount to $4.54 to $5.84 per barrel, although its most likely estimate of $4.59 per barrel is very 

close to the lower end of this range. According to these estimates, each gallon of fuel saved will 

reduce the expected costs disruptions to the U.S. economy by $0.108 to $0.139, with the actual 

value most likely to be $0.109 per gallon. Like the reduction in monopsony costs, the reduction 

in expected disruption costs represents an economic benefit in addition to the value of savings in 

fuel production costs that would result from improving fuel economy. 

Military Security and Strategic Petroleum Reserve Costs

The third component of the external economic costs of importing oil into the U.S. includes 

government outlays for maintaining a military presence to secure the supply of oil imports from 

potentially unstable regions of the world and to protect against their interruption. Some analysts 

also include outlays for maintaining the U.S. Strategic Petroleum Reserve (SPR), which is 

intended to cushion the U.S. economy against the consequences of disruption in the supply of 

imported oil, as additional costs of protecting the U.S. economy from oil supply disruptions. 

NHTSA believes that while costs for U.S. military security may vary over time in response to 

long-term changes in the actual level of oil imports into the U.S., these costs are unlikely to 

decline in response to any reduction in U.S. oil imports resulting from raising future CAFE 

standards for light-duty vehicles. U.S. military activities in regions that represent vital sources of 

oil imports also serve a broader range of security and foreign policy objectives than simply 
VIII-25

protecting oil supplies, and as a consequence are unlikely to vary significantly in response to 

changes in the level of oil imports prompted by higher standards. 

Similarly, while the optimal size of the SPR from the standpoint of its potential influence on 

domestic oil prices during a supply disruption may be related to the level of U.S. oil consumption 

and imports, its actual size has not appeared to vary in response to recent changes in oil imports. 

Thus while the budgetary costs for maintaining the Reserve are similar to other external costs in 

that they are not likely to be reflected in the market price for imported oil, these costs do not 

appear to have varied in response to changes in oil import levels. As a result, the agencies’ 

tentative analysis of benefits from alternative CAFE standards does not include cost savings 

from either reduced outlays for U.S. military operations or maintaining a smaller SPR among the 

external benefits of reducing gasoline consumption and petroleum imports by means of 

tightening future standards. This view concurs with that of the recent ORNL study of economic 

costs from U.S. oil imports, which concludes that savings in government outlays for these 

purposes are unlikely to result form modest reductions in consumption of petroleum products 

and oil imports. 

Thus NHTSA has tentatively included only the likely reductions in monopsony and disruption 

costs from lower U.S. petroleum imports in its estimate of the savings in external economic costs 

from reducing fuel consumption. The updated and revised ORNL estimates suggest that the 

combined reduction in monopsony costs and expected costs to the U.S. economy from oil supply 

disruptions resulting from lower fuel consumption total $0.232 to $0.370 per gallon, with a most 

likely estimate of $0.286 per gallon. This represents the additional economic benefit likely to 

result from each gallon of fuel saved by higher CAFE standards, beyond the savings in resource 

costs for producing and distributing each gallon of fuel saved. NHTSA tentatively employs this 

midpoint estimate in its analysis of the benefits from fuel savings projected to result from 

alternative CAFE standards for model years 2011-15. It also analyzes the effect on these 

benefits estimates from variation in this value over the range from $0.232 to $0.370 per gallon of 

fuel saved. 

The Effect of Fuel Savings on Fuel Supply

Based on a detailed analysis of differences in fuel consumption, petroleum imports, and imports 

of refined petroleum products among the Reference Case, High Economic Growth, and Low 

Economic Growth Scenarios presented in the Energy Information Administration’s Annual 

Energy Outlook 2007, the agency estimates that approximately 50 percent of the reduction in 

fuel consumption resulting from adopting higher CAFE standards is likely to be reflected in 

reduced U.S. imports of refined fuel, while the remaining 50 percent would be expected to be 

reflected in reduced domestic fuel refining. Of this latter figure, 90 percent is anticipated to 

reduce U.S. imports of crude petroleum for use as a refinery feedstock, while the remaining 10 

percent is expected to reduce U.S. domestic production of crude petroleum. Thus on balance, 

each gallon of fuel saved as a consequence of higher CAFE standards is anticipated to reduce 

total U.S. imports of crude petroleum or refined fuel by 0.95 gallons.183 

 

183 This figure is calculated as 0.50 + 0.50*0.9 = 0.50 + 0.45 = 0.95. 
VIII-26

Emissions Reductions Resulting from Fuel Savings 

NHTSA has estimated emissions reductions resulting from fuel savings for purposes of this 

PRIA. However, as indicated previously, NHTSA will consider the potential environmental 

impacts of the proposed standards and reasonable alternatives for purposes of NEPA through the 

NEPA process. 

Criteria Pollutants

While reductions in domestic fuel refining and distribution that result from lower fuel 

consumption will reduce emissions of criteria pollutants, additional vehicle use associated with 

the rebound effect of higher fuel economy will increase emissions of these pollutants (see 

detailed discussion of the Rebound Effect earlier in this chapter). The net effect of stricter 

standards depends on the relative magnitudes of reduced emissions in fuel refining and 

distribution, and increased emissions from vehicle use. Because the relationship between 

emission rates (emissions per gallon refined of fuel or mile driven) from fuel refining and vehicle 

use differs for each specific criteria pollutant, the net effect of fuel savings from the proposed 

standards on total emissions of each pollutant is likely to differ. Predominant criteria pollutants 

emitted in fuel production and use include carbon monoxide (CO), hydrocarbon compounds 

(usually referred to as “volatile organic compounds,” or VOC), nitrogen oxides (NOx), fine 

particulate matter (PM), and sulfur dioxide (SO2). 

For purposes of NHTSA’s PRIA, the increase in emissions of these pollutants from additional 

vehicle use due to the rebound effect is tentatively estimated by multiplying the increase in total 

miles driven by vehicles of each model year and age during future calendar years by age-specific 

emission rates per vehicle-mile for each pollutant. The agencies developed these emission rates 

using EPA’s MOBILE6.2 motor vehicle emissions factor model, with updated vehicle emission 

factors for some pollutants.184 Emissions of these pollutants also occur during crude oil 

extraction and transportation, gasoline refining, and gasoline storage and distribution. The 

reduction in total emissions from each of these sources thus depends on the extent to which fuel 

savings result in lower imports of refined gasoline, or in reduced domestic gasoline refining.185

Based on analysis of changes in U.S. gasoline imports and domestic gasoline consumption 

forecast in AEO 2007, NHTSA tentatively estimates that 50 percent of fuel savings resulting 

from higher CAFE standards will result in reduced imports of refined gasoline, while the 

remaining 50 percent will reduce domestic refining.186 The reduction in domestic refining is 

assumed to leave its sources of crude petroleum unchanged from the mix of 90 percent imports 

and 10 percent domestic production projected by AEO 2007. 

 

184 U.S. Environmental Protection Agency, MOBILE6 Vehicle Emission Modeling Software, available at 

http://www.epa.gov/otaq/m6.htm#m60 (last accessed Sept. 10, 2007). 185 To a lesser extent, they also depend on whether any reduction in domestic gasoline refining is translated into 

reduced imports of crude oil or reduced domestic extraction of petroleum. 

186 Estimates of the response of gasoline imports and domestic refining to fuel savings from stricter standards are 

variable and highly uncertain, but our preliminary analysis indicates that under any reasonable assumption about 

these responses, the magnitude of the net change in criteria pollutant emissions (accounting for both the rebound 

effect and changes in refining emissions) is extremely low relative to their current total. 
VIII-27

NHTSA proposes to estimate reductions in criteria pollutant emissions from gasoline refining 

and distribution using emission rates obtained from Argonne National Laboratories’ Greenhouse 

Gases and Regulated Emissions in Transportation (GREET) model.187 The GREET model 

provides separate estimates of air pollutant emissions that occur in four phases of fuel production 

and distribution: crude oil extraction, crude oil transportation and storage, fuel refining, and fuel 

distribution and storage.188 We tentatively assume that reductions in imports of refined fuel 

would reduce criteria pollutant emissions during fuel storage and distribution only. Reductions 

in domestic fuel refining using imported crude oil as a feedstock are tentatively assumed to 

reduce emissions during crude oil transportation and storage, as well as during gasoline refining, 

distribution, and storage, simply because less of it would be occurring. Similarly, reduced 

domestic fuel refining using domestically-produced crude oil is tentatively assumed to reduce 

emissions during all phases of gasoline production and distribution.189

The net changes in emissions of each criteria pollutant are calculated by comparing the increases 

in their emissions that result from increased vehicle use to the reductions that result from lower 

domestic fuel refining and distribution. The net change in emissions of each criteria pollutant is 

converted to an economic value using estimates of the economic costs per ton emitted (which 

result primarily from damages to human health) developed by EPA and submitted to the federal 

Office of Management and Budget for review. For certain criteria pollutants, EPA estimates 

different per-ton costs for increases in emissions from vehicle use than for reductions in 

emissions from fuel refining, reflecting differences in their typical geographic distributions, 

contributions to ambient pollution levels, and resulting population exposure. The per unit costs 

for each criteria pollutant is summarized in Table VIII-B. 

Greenhouse Gases

NHTSA has taken the economic benefits of reducing CO2 emission into account in this 

rulemaking, both in developing proposed CAFE standards and in assessing the economic 

benefits of each alternative that was considered. As noted above, the 9th Circuit found in CBD

that NHTSA had been arbitrary and capricious in deciding not to monetize the benefit of 

reducing CO2 emissions, saying that the agency had not substantiated the conclusion in its April 

2006 final rule that the appropriate course was not to monetize (i.e., quantify the value of) carbon 

emissions reduction at all. 

To this end, NHTSA reviewed published estimates of the “social cost of carbon emissions” 

(SCC). The SCC refers to the marginal cost of additional damages caused by the increase in 

expected climate impacts resulting from the emission of each additional metric ton of carbon, 

 

187 Argonne National Laboratories, The Greenhouse Gas and Regulated Emissions from Transportation (GREET) 

Model, Version 1.6, April 2005, available at http://www.transportation.anl.gov/software/GREET/index.html (last 

accessed Sept. 10, 2007). 

188 Emissions that occur during vehicle refueling at retail gasoline stations (primarily evaporative emissions of 

volatile organic compounds, or VOCs) are already accounted for in the “tailpipe” emission factors used to estimate 

the emissions generated by increased light truck use. GREET estimates emissions in each phase of gasoline 

production and distribution in mass per unit of gasoline energy content; these factors are then converted to mass per 

gallon of gasoline using the average energy content of gasoline. 

189 In effect, this assumes that the distances crude oil travels to U.S. refineries are approximately the same regardless 

of whether it travels from domestic oilfields or import terminals, and that the distances that gasoline travels from 

refineries to retail stations are approximately the same as those from import terminals to gasoline stations. 
VIII-28

which is emitted in the form of CO2.

190 It is typically estimated as the net present value of the 

impact over some time period (100 years or longer) of one additional ton of carbon emitted into 

the atmosphere. Because accumulated concentrations of greenhouse gases in the atmosphere and 

the projected impacts on global climate are increasing over time, the economic damages resulting 

from each additional ton of CO2 emissions in future years are believed to be greater as a result. 

Thus estimates of the SCC are typically reported for a specific year, and these estimates are 

generally larger for emissions in more distant future years. 

There is substantial variation among different authors’ estimates of the SCC, much of which can 

be traced to differences in their underlying assumptions about several variables. These include 

the sensitivity of global temperatures and other climate attributes to increasing atmospheric 

concentrations of greenhouse gases, discount rates applied to future economic damages from 

climate change, whether damages sustained by developing regions of the globe should be 

weighted more heavily than damages to developed nations, how long climate changes persist 

once they occur, and the economic valuation of specific climate impacts.191 

Taken as a whole, recent estimates of the SCC may underestimate the true damage costs of 

carbon emissions because they often exclude damages caused by extreme weather events or 

climate response scenarios with low probabilities but potentially extreme impacts, and may 

underestimate the climate impacts and damages that could result from multiple stresses on the 

global climatic system. At the same time, however, many studies fail to consider potentially 

beneficial impacts of climate change, and do not adequately account for how future development 

patterns and adaptations could reduce potential impacts from climate change or the economic 

damages they cause. 

Given the uncertainty surrounding estimates of the SCC, the use of any single study may not be 

advisable since its estimate of the SCC will depend on many assumptions made by its authors. 

The Working Group II’s contribution to the Fourth Assessment Report of the United Nations 

Intergovernmental Panel on Climate Change (IPCC)192 notes that: 

The large ranges of SCC are due in the large part to differences in assumptions 

regarding climate sensitivity, response lags, the treatment of risk and equity, 

economic and non-economic impacts, the inclusion of potentially catastrophic 

losses, and discount rates. 

 Although the IPCC does not recommend a single estimate of the SCC, it does cite the Tol 

(2005) study on four separate occasions (pages 17, 65, 813, 822) as the only available survey of 

the peer-reviewed literature that has itself been subjected to peer review. Tol developed a 

 

190 Carbon itself accounts for 12/44, or about 27%, of the mass of carbon dioxide (12/44 is the ratio of the molecular 

weight of carbon to that of carbon dioxide). Thus each ton of carbon emitted is associated with 44/12, or 3.67, tons 

of carbon dioxide emissions. Estimates of the SCC are typically reported in dollars per ton of carbon, and must be 

divided by 3.67 to determine their equivalent value per ton of carbon dioxide emissions. 

191 For a discussion of these factors, see Yohe, G.W., R.D. Lasco, Q.K. Ahmad, N.W. Arnell, S.J. Cohen, C. Hope, 

A.C. Janetos and R.T. Perez, 2007: Perspectives on climate change and sustainability. Climate Change 2007: 

Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. 

Hanson, Eds., Cambridge University Press, Cambridge, UK, pp. 821-824. 

192 Climate Change 2007 – Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth 

Assessment Report of the IPCC, 17. Available at http://www.ipcc-wg2.org (last accessed <Feb. 4, 2008>). 
VIII-29

probability function using the SCC estimates of the peer reviewed literature and found estimates 

ranging from less than zero to over $200 per metric ton of carbon. In an effort to resolve some 

of the uncertainty in reported estimates of climate damage costs from carbon emissions, Tol 

(2005) reviewed and summarized one hundred and three estimates of the SCC from 28 published 

studies. He concluded that when only peer-reviewed studies published in recognized journals 

are considered, “...climate change impacts may be very uncertain but is unlikely that the 

marginal damage costs of carbon dioxide emissions exceed $50 per [metric] ton carbon [about 

$14 per metric ton of CO2].” 193 He also concluded that the costs may be less than $14. 

Because of the number of assumptions required by each study, the wide range of uncertainty 

surrounding these assumptions, and their critical influence on the resulting estimates of climate 

damage costs, some studies have undoubtedly produced estimates of the SCC that are 

unrealistically high, while others are likely to have estimated values that are improbably low. 

Using a value for the SCC that reflects the central tendency of estimates drawn from many 

studies reduces the chances of relying on a single estimate that subsequently proves to be biased. 

It is important to note that estimates of the SCC almost invariably include the value of worldwide 

damages from potential climate impacts caused by carbon dioxide emissions, and are not 

confined to damages likely to be suffered within the U.S. In contrast, the other estimates of costs 

and benefits of increasing fuel economy included in this proposal include only the economic 

values of impacts that occur within the U.S. For example, the economic value of reducing 

criteria air pollutant emissions from overseas oil refineries is not counted as a benefit resulting 

from this rule, because any reduction in damages to health and property caused by overseas 

emissions are unlikely to be experienced within the U.S. 

In contrast, the reduced value of transfer payments from U.S. oil purchasers to foreign oil 

suppliers that results when lower U.S. oil demand reduces the world price of petroleum (the 

reduced “monopsony effect”) is counted as a benefit of reducing fuel use.194 If the agency’s 

analysis was conducted from a worldwide rather than a U.S. perspective, however, the benefit 

from reducing air pollution overseas would be included, while reduced payments from U.S. oil 

consumers to foreign suppliers would not. 

In order to be consistent with NHTSA’s use of exclusively domestic costs and benefits in prior 

CAFE rulemakings, the appropriate value to be placed on changes climate damages caused by 

carbon emissions should be one that reflects the change in damages to the United States alone. 

Accordingly, NHTSA notes that the value for the benefits of reducing CO2 emissions might be 

restricted to the fraction of those benefits that are likely to be experienced within the United 

States. 

Although no estimates of benefits to the U.S. itself that are likely to result from reducing CO2

emissions are currently available, NHTSA expects that if such values were developed, the 

 

193 Tol, Richard. The marginal damage costs of carbon dioxide emissions: an assessment of the uncertainties. 

Energy Policy 33 (2005) 2064–2074, 2072. The summary SCC estimates reported by Tol are assumed to be 

denominated in U.S. dollars of the year of publication, 2005. 

194 The reduction in payments from U.S. oil purchasers to domestic petroleum producers is not included as a benefit, 

since it represents a transfer that occurs entirely within the U.S. economy. 
VIII-30

agency would employ those rather than global benefit estimates in its analysis. NHTSA also 

anticipates that if such values were developed, they would be lower than comparable global 

values, since the U.S. is likely to sustain only a fraction of total global damages resulting from 

climate change. 

 

In the meantime, the agency has elected to use the IPCC estimate of $43 per metric ton of carbon 

as an upper bound on the benefits resulting from reducing each metric ton of U.S. emissions. 195 

This corresponds to approximately $12 per metric ton of CO2 when expressed in 2006 dollars. 

This estimate is based on the 2005 Tol study.196 The Tol study is cited repeatedly as an 

authoritative survey in various IPCC reports, which are widely accepted as representing the 

general consensus in the scientific community on climate change science. Since the IPCC 

estimate includes the worldwide costs of potential damages from carbon dioxide emissions, 

NHTSA has elected to employ it as an upper bound on the estimated value of the reduction in 

U.S. domestic damage costs that is likely to result from lower CO2 emissions.197 

The IPCC Working Group II Fourth Assessment Report (2007, p. 822) further suggests that the 

SCC of carbon is growing at an annual 2.4 percent growth rate, based on estimated increases in 

damages from future emissions reported in published studies. NHTSA has also elected to apply 

this growth rate to Tol’s original 2005 estimate. Thus by 2011, the agency estimates that the 

upper bound on the benefits of reducing CO2 emissions will have reached about $14 per metric 

ton of CO2, and will continue increase by 2.4 percent annually thereafter. 

In setting a lower bound, the agency agrees with the IPCC Working Group II (2007) report that 

“significant warming across the globe and the locations of significant observed changes in many 

systems consistent with warming is very unlikely to be due solely to natural variability of 

temperatures or natural variability of the systems” (pp. 9). Although this finding suggests that 

the global value of economic benefits from reducing carbon dioxide emissions is unlikely to be 

zero, it does not necessarily rule out low or zero values for the benefit to the U.S. itself from 

reducing emissions. 

For most of the analysis it performed to develop this proposal, NHTSA required a single estimate 

for the value of reducing CO2 emissions. The agency thus elected to use the midpoint of the 

range from $0 to $14 (or $7.00) per metric ton of CO2 as the initial value for the year 2011, and 

assumed that this value would grow at 2.4 percent annually thereafter. This estimate is 

employed for the analyses conducted using the Volpe CAFE model to support development of 

the proposed standards. The agency also conducted sensitivity analyses of the benefits from 

 

195 The estimate of $43 per ton of carbon emissions is reported by Tol (p. 2070) as the mean of the “best” estimates 

reported in peer-reviewed studies (see fn. 4). It thus differs from the mean of all estimates reported in the peerreviewed studies surveyed by Tol. The $43 per ton value is also attributed to Tol by IPCC Working Group II 

(2007), p. 822. 

196 Tol’s more recent (2007) and inclusive survey has been published online with peer-review comments. The 

agency has elected not to rely on the estimates it reports, but will consider doing so in its analysis of the final rule if 

the survey has been published, and will also consider any other newly-published evidence. 

197 For purposes of comparison, we note that in the rulemaking to establish CAFE standards for MY 2008-11 light 

trucks, NRDC recommended a value of $10 to $25 per ton of CO2 emissions reduced by fuel savings and both 

Environmental Defense and Union of Concerned Scientists recommended a value of $50 per ton of carbon 

(equivalent to about $14 per ton of CO2 emissions). 
VIII-31

reducing CO2 emissions using both the upper ($14 per metric ton) and lower ($0 per metric ton) 

bounds of this range. 

NHTSA seeks comment on its tentative conclusions for the value of the SCC, the use of a 

domestic versus global value for the economic benefit of reducing CO2 emissions, the rate at 

which the value of the SCC grows over time, the desirability of and procedures for incorporating 

benefits from reducing emissions of greenhouse gases other than CO2, and any other aspects of 

developing a reliable SCC value for purposes of establishing CAFE standards. 

Consumer Benefits from Additional Driving

The increase in travel associated with the rebound effect produces additional benefits to vehicle 

owners, which reflect the value to drivers and other vehicle occupants of the added (or more 

desirable) social and economic opportunities that become accessible with additional travel. As 

evidenced by the fact that they elect to make more frequent or longer trips when the cost of 

driving declines, the benefits from this added travel are at least as large as drivers’ added costs 

for the fuel it consumes (measured at the improved level of fuel economy resulting from stricter 

CAFE standards).198 The benefits from additional rebound effect travel also include the 

consumer surplus received by vehicle buyers who value the opportunities that increased travel 

makes available to them at more than the fuel cost of the additional driving. Because it depends 

on the improvement in fuel economy, the value of benefits from increased vehicle use changes 

by model year and alternative CAFE standard, and is shown in Tables VIII-5 through VIII-9. 

Added Costs from Congestion, Crashes, and Noise

While it provides some benefits to drivers, increased vehicle use associated with the fuel 

economy rebound effect can also contribute to increased traffic congestion, motor vehicle 

crashes, and highway noise. Additional vehicle use can contribute to traffic congestion and 

delays by increasing recurring congestion on heavily-traveled roadways during peak travel 

periods, depending on how the additional travel is distributed over the day and on where it 

occurs. By increasing the number of crashes and disabled vehicles, added driving can also 

increase the delays that often result from these incidents, although the extent to which it actually 

does so again depends on when and where the added travel occurs. In either case, any added 

delays impose higher costs on drivers and other vehicle occupants in the form of increased travel 

time and operating expenses, and these should be considered as an additional economic cost 

associated with the rebound effect. Because drivers do not take these added costs into account in 

deciding when to make trips or where they travel, they must be accounted for separately as a cost 

of the added driving associated with the rebound effect. 

Increased passenger car and light truck use due to the rebound effect may also increase the costs 

associated with traffic crashes. Drivers presumably take account of the potential costs they (and 

the other occupants of their vehicles) face from the possibility of being involved in a crash when 

they decide to make additional trips. However, they probably do not consider all of the potential 

costs they impose on occupants of other vehicles and on pedestrians when crashes occur, so any 

increase in these “external” crash costs must be considered as another cost of additional reboundeffect driving. Like increased delay costs, any increase in these external crash costs caused by 

 

198 These benefits are included in the value of fuel savings reported in Tables VIII-5 through VIII-9. 
VIII-32

added driving is likely to depend on the traffic conditions under which it takes place, since 

crashes are more frequent in heavier traffic, but their severity may be reduced by the slower 

speeds at which heavier traffic typically moves. Thus estimates of the increase in external crash 

costs from the rebound effect also need to account for when and where the added driving occurs. 

Finally, added vehicle use from the rebound effect may also increase traffic noise. Noise 

generated by vehicles causes inconvenience, irritation, and potentially even discomfort to 

occupants of other vehicles, to pedestrians and other bystanders, and to residents or occupants of 

surrounding property. Because none of these effects are likely to be taken into account by the 

drivers whose vehicles contribute to traffic noise, they represent additional externalities 

associated with motor vehicle use. Although there is considerable uncertainty in estimating its 

value, the added inconvenience and irritation caused by increased traffic noise imposes economic 

costs on those it affects, and these added costs are unlikely to be taken into account by drivers of 

the vehicles that cause it. Thus any increase in noise costs resulting from added vehicle use must 

be included together with other increased external costs from the rebound effect. 

Our analysis uses estimates of the congestion costs, crash costs, and noise costs for pickup trucks 

and vans developed by the Federal Highway Administration to estimate the increased external 

costs caused by added light truck use from the rebound effect.199 These estimates are intended to 

measure the increases in external costs – that is, the marginal external costs – from added 

congestion, property damages and injuries in traffic crashes, and noise levels caused by 

additional usage of light trucks that are borne by persons other than their drivers. FHWA’s 

“Middle” estimates for congestion, crash, and noise costs imposed by passenger cars are 5.22 

cents, 2.26 cents and 0.07 cents per vehicle mile when expressed in 2006 dollars.200 For pickup 

trucks and vans these costs are 4.66 cents, 2.51 cents, and 0.07 cents per vehicle-mile. These 

costs are multiplied by the estimated increases in passenger car and light truck use from the 

rebound effect during each year of the affected model years’ lifetimes in the fleet to yield the 

estimated increases in congestion, crash, and noise externality costs during that year. The 

resulting estimates are discounted to their present values as of the date each model year is sold 

and summed to obtain their total values. 

The Federal Highway Administration’s estimates of these costs agree closely with some other 

recent estimates. For example, recent published research conducted by Resources for the Future 

(RFF) estimates marginal congestion and external crash costs for increased light-duty vehicle use 

in the U.S. to be 3.9 and 3.4 cents per vehicle-mile when converted to 2006 dollars.201 These 

estimates incorporate careful adjustments of congestion and crash costs that are intended to 

reflect the traffic conditions under which additional driving is likely to take place, as well as its 

likely effects on both the frequency and severity of motor vehicle crashes. 

 

199 These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study. 

 

200 Federal Highway Administration, 1997 Federal Highway Cost Allocation Study, Tables V-22, V-23, and V-24, 

http://www.fhwa.dot.gov/policy/hcas/final/index.htm. The higher congestion cost for automobiles than for light 

trucks reflects the larger fraction of auto than of light truck use that occurs within congested urban areas. 

201 Ian W.H. Parry and Kenneth A. Small, “Does Britain or the U.S. Have the Right Gasoline Tax?” Discussion 

Paper 02-12, Resources for the Future, March 2002, pp. 19 and Table 1, http://www.rff.org/rff/Documents/RFF-DP02-12.pdf. 
VIII-33

Costs from Increased Air Pollutant Emissions 

Finally, as noted previously under Emissions Reductions Resulting from Fuel Savings, additional 

passenger car and light truck use associated with the rebound effect will increase emissions of air 

pollutants that occur as motor vehicles are driven. Predominant air pollutants emitted by motor 

vehicles include hydrocarbon compounds (usually referred to as “volatile organic compounds,” 

or VOC), nitrogen oxides (NOx), fine particulate matter (PM), and sulfur dioxide (SO2). The 

increased use of passenger cars and light trucks that occurs through the rebound effect causes 

higher emissions of these “criteria” pollutants, since Federal standards limit their permissible 

emissions by motor vehicles on a per-mile basis. The increase in emissions of these pollutants 

from additional vehicle use is estimated by multiplying the increase in total miles driven by 

vehicles of each model year and age during a calendar year by age-specific emission rates per 

vehicle-mile developed using the U.S. Environmental Protection Agency’s MOBILE6.2 motor 

vehicle emissions factor model202. The monetized value of changes in criteria pollutant emissions 

(fine PM, NOx, SO2, VOCs andCO) are derived from EPA estimates of the value of health and welfarerelated damages (incurred or avoided). These estimates, expressed as dollars per ton, are based on the 

benefits associated with recently-adopted regulations that limit emissions of air pollutants from mobile 

sources, a category that includes passenger cars, light trucks, and other highway vehicles.

203 

The Value of Increased Driving Range 

 Improving the fuel economy of passenger cars and light-duty trucks may also increase their 

driving range before they require refueling. By reducing the frequency with which drivers 

typically refuel their vehicles, and by extending the upper limit of the range they can travel 

before requiring refueling, improving fuel economy thus provides some additional benefits to 

their owners. (Alternatively, if manufacturers respond to improved fuel economy by reducing 

the size of fuel tanks to maintain a constant driving range, the resulting cost saving will 

presumably be reflected in lower vehicle sales prices.) 

No direct estimates of the value of extended vehicle range are readily available, so the agency’s 

analysis calculates the reduction in the annual number of required refueling cycles that results 

from improved fuel economy, and applies DOT-recommended values of travel time savings to 

convert the resulting time savings to their economic value.204 As an illustration of how the value 

of extended refueling range is estimated, a typical small light truck model has an average fuel 

tank size of approximately 20 gallons. Assuming that drivers typically refuel when their tanks 

are 20 percent full (i.e., 4 gallons in reserve), increasing this model’s actual on-road fuel 

economy from 24 to 25 mpg would extend its driving range from 384 miles (= 16 gallons x 24 

mpg) to 400 miles (= 16 gallons x 25 mpg). Assuming that it is driven 12,000 miles/year, this 

reduces the number of times it needs to be refueled each year from 31.3 (= 12,000 miles per year 

/ 384 miles per refueling) to 30.0 (= 12,000 miles per year / 400 miles per refueling), or by 1.3 

refuelings per year. 

 

202 U.S. Environmental Protection Agency, MOBILE6 Vehicle Emission Modeling Software, 

http://www.epa.gov/otaq/m6.htm#m60 

203 EPA, “Mobile Source $ per Ton Estimates,” document provided to NHTSA by EPA Office of Transportation and 

Air Quality staff, June 26, 2007. 

204 See http://ostpxweb.dot.gov/policy/Data/VOT97guid.pdf and 

http://ostpxweb.dot.gov/policy/Data/VOTrevision1_2-11-03.pdf
VIII-34

Weighted by the nationwide mix of urban (about 2/3) and rural (about 1/3) driving and average 

vehicle occupancy for all driving trips (1.6 persons), the DOT-recommended value of travel time 

per vehicle-hour is $24.00 (in 2006 dollars).205 Assuming that locating a station and filling up 

requires ten minutes, the annual value of time saved as a result of less frequent refueling amounts 

to $5.20 (calculated as 10/60 x 1.3 x $24.00). This calculation is repeated for each future 

calendar year that light trucks of each model year affected by the alternative CAFE standards 

considered in this rule would remain in service. Like fuel savings and other benefits, however, 

the value of this benefit declines over a model year’s lifetime, because a smaller number of 

vehicles originally produced during that model year remain in service each year, and those 

remaining in service are driven fewer miles. 

The following Table summarizes the values used to calculate the impacts of each scenario. 

Table VIII-B 

Economic Values for Benefits Computations (2006$) 

 

Rebound Effect (VMT Elasticity) -0.15 

Discount Rate Applied to Future Benefits 7% 

Payback Period (years) 5.0 

"Gap" between Test and On-Road MPG 20% 

Value of Travel Time per Vehicle ($/hour) $24.00 

Economic Costs of Oil Imports ($/gallon) 

"Monopsony" Component $0.182 

Price Shock Component $0.113 

Military Security Component $ - 

Total Economic Costs ($/gallon) $0.295 

Total Economic Costs ($/BBL) $12.38 

External Costs from Additional Automobile Use 

Due to "Rebound" Effect ($/vehicle-mile) 

Congestion $0.052 

Accidents $0.023 

Noise $0.001 

External Costs from Additional Light Truck Use 

Due to "Rebound" Effect ($/vehicle-mile) 

Congestion $0.047 

Accidents $0.025 

Noise $0.001 

Emission Damage Costs 

Carbon Monoxide ($/ton) $ - 

Volatile Organic Compounds ($/ton) $1,700 

 

205 The hourly wage rate during 2006 is estimated to be $24.00. Personal travel (94.4% of urban travel) is valued at 

50 percent of the hourly wage rate. Business travel (5.6% or urban travel) is valued at 100 percent of the hourly 

wage rate. For intercity travel, personal travel (87%) is valued at 70 percent of the wage rate, while business travel 

(13%) is valued at 100 percent of the wage rate. The resulting values of travel time are $12.67 for urban travel and 

$17.66 for intercity travel, and must be multiplied by vehicle occupancy (1.6) to obtain the estimate value of time 

per vehicle hour. 
VIII-35

Nitrogen Oxides ($/ton) $3,900 

Particulate Matter ($/ton) $164,000 

Sulfur Dioxide ($/ton) $16,000 

Carbon Dioxide ($/metric ton) $ 7.00 

Annual Increase in CO2 Damage Cost 2.4% 
VIII-36

Summary of Benefits 

Benefits were calculated separately for passenger cars and light trucks under each alternative 

CAFE requirement for each model year covered by this proposal. In Tables VIII-5 through VIII9, the societal impacts for passenger car CAFE standards under the proposed Optimized Net 

Benefits alternative is shown over the 2011 through 2015 model years. Table VIII-10 

summarizes the impacts for passenger cars across all 5 model years. In Tables VIII-11 through 

VIII-15 the societal impacts for light truck CAFE standards under the Optimized Net Benefits 

alternative is shown over the 2011 through 2015 model years. Table VIII-16 summarizes the 

impacts for light trucks across all 5 model years. Table VIII-17 summarizes the impacts across 

both the passenger car and light truck fleets for the 5 model years combined. These tables 

include undiscounted values as well as present value calculations at 3 percent and 7 percent. 

They also show changes in the physical units of measure that produced these values. Negative 

values in these tables reflect net reductions in fuel consumption or emissions and their resulting 

economic impacts, which represent benefits from the proposal, while positive values represent 

increasing emissions, congestion, noise or crash severity and their added costs. The net social 

benefit from these societal impacts is shown on the Total line in each table. 

The proposed standards for passenger cars would save approximately 19 billion gallons of fuel 

and prevent 178 million metric tons of tailpipe CO2 emissions over the lifetime of the passenger 

cars sold during those model years, compared to the fuel savings and emissions reductions that 

would occur if the standards remained at the adjusted baseline (i.e., the higher of manufacturer’s 

plans or the manufacturer’s required level of average fuel economy for MY 2010). 

The total value of societal benefits of the proposed passenger car standards would be 

approximately $31 billion206 over the lifetime of the 5 model years combined. This estimate of 

societal benefits includes direct impacts from lower fuel consumption as well as externalities, 

and also reflects offsetting societal costs resulting from the rebound effect. Direct benefits to 

consumers, including fuel savings, account for 85% ($29.5 billion) of the roughly $35 billion in 

gross consumer benefits207 resulting from increased passenger car CAFE. Petroleum market 

externalities account for roughly 10% ($3.6 billion). Environmental externalities, i.e., reduction 

of air pollutants accounts for roughly 5% ($1.8 billion). Over half of this $1.8 billion is the 

result of greenhouse gas (primarily CO2) reduction ($1.0 billion). Increased congestion, noise 

and accidents from increased driving will offset roughly $3.8 billion of the $35 billion in gross 

consumer benefits, leaving total consumer benefits of $31 billion. 

The proposed standards for light trucks would save approximately 36 billion gallons of fuel and 

prevent 343 million metric tons of tailpipe CO2 emissions over the lifetime of the light trucks 

sold during those model years, compared to the fuel savings and emissions reductions that would 

 

206 The $31 billion estimate is based on a 7% discount rate for valuing future impacts. NHTSA estimated benefits 

using both 7% and 3% discount rates. Under a 3% rate, net consumer benefits for passenger car CAFE 

improvements total $36 billion. 

207 Gross consumer benefits are benefits measured prior to accounting for the negative impacts of the rebound effect. 

They include fuel savings, consumer surplus from additional driving, reduced refueling time, reduced criteria 

pollutants, and reduced greenhouse gas production. Negative impacts from the rebound effect include added 

congestion, noise, and crash costs due to additional driving. 
VIII-37

occur if the standards remained at the adjusted baseline (i.e., the higher of manufacturer’s plans 

or the manufacturer’s required level of average fuel economy for MY 2010). 

The total value of societal benefits of the proposed light truck standards would be approximately 

$57 billion208 over the lifetime of the 5 model years combined. This estimate of societal benefits 

includes direct impacts from lower fuel consumption as well as externalities, and also reflects 

offsetting societal costs resulting from the rebound effect. Direct benefits to consumers, 

including fuel savings, account for 84% ($52.7 billion) of the roughly $63 billion in gross

consumer benefits resulting from increased light truck CAFE. Petroleum market externalities 

account for roughly 10% ($6.5 billion). Environmental externalities, i.e., reduction of air 

pollutants accounts for roughly 6% ($3.5 billion). Over half of this $3.5 billion is the result of 

greenhouse gas (primarily CO2) reduction ($1.9 billion). Increased congestion, noise and 

accidents from increased driving will offset roughly $5.4 billion of the $63 billion in gross 

consumer benefits, leaving total consumer benefits of $57 billion. 

Tables VIII-18, 19, and 20 summarize the fuel savings from all alternatives over model years 

2011-2015 for passenger cars and light trucks. Each table reports total fuel savings (in millions 

of gallons) over the lifetime of vehicles manufactured during each model year that are projected 

to occur under each scenario. As the tables indicate, there is a steady increase in fuel savings for 

both passenger cars and light trucks with each successive model year under all 7 scenarios. As 

would be expected, benefit levels parallel the increasing stringency of the various alternatives 

that were examined. The two Optimized scenarios pushes technology up to the point where is 

ceases to be cost effective, but the 3% based scenario produces more benefits than the 7% based 

scenario because it places a higher value on benefits experienced in the future. The TC=TB 

scenario produces benefits that exceed the Optimized scenario because it allows benefits that 

accrue from cost-beneficial technologies to offset costs that accrue from technologies that are not 

cost-beneficial. As might be expected, the High Technology scenario, which assumes the 

maximum use of all available technologies in all vehicles regardless of cost, produces higher 

savings than any of the 6 other scenarios in all model years. The 25% Below Optimized, 25% 

Above Optimized, and 50% Above Optimized scenarios were designed to produce results 

relative to the Optimized scenario, and their benefits accordingly reflect this. 

Tables VIII-21, 22, 23, 24, 25 and 26 summarize the total social benefits from all alternatives 

over the 2011-2015 model years for passenger cars and light trucks at both 3 percent and 7 

percent discount rates. These tables summarize the value of net consumer benefits over the 

lifetime of the vehicles manufactured during each model year and scenario. There is a steady 

increase in the social value of fuel savings and other benefits with each model year under all 7 

scenarios, which mirrors the trends in fuel savings noted above. Likewise, the value of societal 

benefits mirrors the trends in stringency across alternative scenarios. 

 

208 The $57 billion estimate is based on a 7% discount rate for valuing future impacts. NHTSA estimated benefits 

using both 7% and 3% discount rates. Under a 3% rate, net consumer benefits for light truck CAFE improvements 

total $72 billion. 
VIII-38

 

Table VIII-5 

 Lifetime Monetized Societal Impacts, Optimized CAFE, MY 2011, 

 Passenger Cars 

 

Societal 

Effect 

Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted 

Value @ 3% 

Present 

Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -1,563,348(kgal) -3,082,877 -2,538,092 -2,074,331 

Consumer 

Surplus from 

Additional 

Driving 6,154,197(kmiles) -382,541 -320,292 -261,888 

Refueling 

Time Value -8,064,500 

(hours) -193,548 

-161,963 

-132,232 

Petroleum 

Market 

Externalities -1,563,348(kgal) -437,683 -366,257 -299,025 

Congestion 

Costs 

6,154,197 

(kmiles) 321,249 268,824 219,478 

Noise Costs 6,154,197 

(kmiles) 4,308 3,605 2,943 

Crash Costs 6,154,197 

(kmiles) 139,085 116,387 95,023 

CO2 -15 (mmT) -119,479 -98,360 -78,834 

CO 281,949(tons) 0 0 0 

VOC -4,589 (tons) -7,801 5,801 -4,102 

NOX -7,728 (tons) -30,141 -23,583 -17,773 

PM -191 (tons) -31,401 -25,396 -20,088 

SOX -2,261(tons) -36,178 -30,274 -24,717 

Total -3,807,007 -3,181,201 -2,595,546 

 
VIII-39

 Table VIII-6 

Lifetime Monetized Societal Impacts, 

Optimized CAFE, MY 2012, Passenger Cars 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present Discounted 

Value @ 3% 

Present 

Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -2,967,962 (k gal) -5,819,490 -4,859,768 -3,961,065 

Consumer Surplus 

from Additional 

Driving 11,771,196(kmiles) -721,598 -603,190 -492,159 

Refueling Time 

Value 14,848,833 (hours) -356,372 -298,216 -243,474 

Petroleum Market 

Externalities -2,967,962 (k gal) -830,928 -695,329 -567,691 

Congestion Costs 11,771,196 (kmiles) 614,456 514,183 419,797 

Noise Costs 11,771,196 (kmiles) 8,240 6,895 5,629 

Crash Costs 11,771,196 (kmiles) 266,029 222,616 181,751 

CO2 -28 (mmT) -238,466 -196,315 -157,343 

CO 86,340(tons) 0 0 0 

VOC 1,086 (tons) 1,851 1,300 840 

NOX -6,044 (tons) -23,570 -20,210 -16,942 

PM -513(tons) -84,176 -70,096 -56,968 

SOX -4,158 (tons) -66,522 -55,667 -45,448 

Total -7,250,243 -6,053,796 -4,933,071 

 
VIII-40

Table VIII-7 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2013, Passenger Cars 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present 

Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -3,716,507 (k gal) -7,272,841 -6,064,046 -4,932,346 

Consumer 

Surplus from 

Additional 

Driving 14,947,099 (kmiles) -902,219 -753,173 -613,455 

Refueling Time 

Value -18,783,958 (hours) -450,815 -377,246 -307,997 

Petroleum 

Market 

Externalities -3,716,507 (k gal) -1,040,492 -870,693 -710,865 

Congestion 

Costs 14,947,099 (kmiles) 780,239 652,911 533,060 

Noise Costs 14,947,099 (kmiles) 10,463 8,756 7,148 

Crash Costs 14,947,099 (kmiles) 337,804 282,678 230,788 

CO2 -36 (mmT) -305,686 -251,653 -201,695 

CO 104,544 (tons) 0 0 0 

VOC -1,946 (tons) -3,308 -2,545 -1,882 

NOX -10,551 (tons) -41,151 -33,835 -27,078 

PM -605 (tons) -99,250 -81,737 -65,701 

SOX -5,271 (tons) -84,335 -70,572 -57,618 

Total -9,071,590 -7,561,156 -6,147,651 
VIII-41

 Table VIII-8 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2014, Passenger Cars 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present Discounted 

Value @ 3% 

Present 

Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -4,771,444(k gal) -9,340,878 -7,780,728 -6,319,874 

Consumer 

Surplus from 

Additional 

Driving 18,970,569 (miles) -1,145,324 -955,266 -777,109 

Refueling Time 

Value 24,182,292 (hours) -580,375 -485,663 -396,513 

Petroleum 

Market 

Externalities -4,771,444(k gal) -1,335,837 -1,117,841 -912,645 

Congestion 

Costs 18,970,569 (miles) 990,264 828,662 676,549 

Noise Costs 18,970,569 (miles) 13,279 11,112 9,072 

Crash Costs 18,970,569 (miles) 428,735 358,769 292,912 

CO2 -46 (mmT) -401,009 -330,127 -264,593 

CO -147,821 (tons) 0 0 0 

VOC -2,690 (tons) -4,573 -3,520 -2,603 

NOX -13,709 (tons) -53,464 -43,909 -35,090 

PM -793 (tons) -130,021 -106,690 -85,396 

SOX -6,764 (tons) -108,229 -90,567 -73,942 

Total -11,667,432 -9,715,770 -7,889,231 
VIII-42

 Table VIII-9 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2015, Passenger Cars 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -5,716,339(k gal) -11,171,665 -9,298,183 -7,542,913 

Consumer 

Surplus from 

Additional 

Driving 

22,781,264 

(kmiles) -1,363,084 -1,135,944 -922,974 

Refueling Time 

Value 

28,938,083 (hours) -694,514 -581,176 -474,492 

Petroleum 

Market 

Externalities -5,716,339 (k gal) -1,600,375 -1,339,209 -1,093,378 

Congestion 

Costs 

22,781,264 

(kmiles) 1,189,182 995,119 812,450 

Noise Costs 22,781,264 

(kmiles) 15,947 13,345 10,895 

Crash Costs 22,781,264 

(kmiles) 517,857 430,847 351,751 

CO2 -54 (mmT) -488,493 -402,147 -322,314 

CO -273,604 (tons) 0 0 0 

VOC -4,634 (tons) -7,878 -6,026 -4,412 

NOX -17,657 (tons) -68,864 -56,138 -44,462 

PM -958 (tons) -157,158 -127,963 -101,508 

SOX -8,104 (tons) -129,669 -108,508 -88,590 

Total -13,961,714 -11,615,995 -9,419,948 
VIII-43

 Table VIII-10 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2011- 2015, Passenger Cars 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -18,735,610 (kgal) -36,637,752 -28,459,291 -24,830,539

Consumer 

Surplus from 

Additional 

Driving 74,624,325 (kmiles) -4,514,765 -3,507,694 -3,067,584

Refueling Time 

Value -94,817,655 (hours) -2,275,624 -1,774,730 -1,554,709

Petroleum 

Market 

Externalities -18,735,610 (kgal) -5,245,315 -4,090,602 -3,583,605

Congestion 

Costs 74,624,325 (kmiles) 3,895,390 3,038,066 2,661,335

Noise Costs 74,624,325 (kmiles) 52,237 40,740 35,688

Crash Costs 74,624,325 (kmiles) 1,686,510 1,315,331 1,152,225

CO2 -178 (mmT) -1,553,133 -1,190,956 -1,024,777

CO -721,578 (tons) 0 0 0

VOC -12,770 (tons) -21,709 -15,625 -12,160

NOX -55,689 (tons) -217,189 -165,746 -141,345

PM -3,061 (tons) -502,006 -385,311 -329,661

SOX -26,558 (tons) -424,934 -331,395 -290,316

Total -45,758,291 -35,527,213 -30,985,447

 
VIII-44

 Table VIII-11 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2011, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -2,403,611 (kgal) -4,811,383 -3,883,226 -3,087,364

Consumer 

Surplus from 

Additional 

Driving 7,666,300 (kmiles) -595,411 -481,267 -383,161

Refueling Time 

Value -9,383,882 (hours) -225,213 -182,196 -144,998

Petroleum 

Market 

Externalities -2,403,611 (kgal) -672,927 -544,395 -433,248

Congestion 

Costs 7,666,300 (kmiles) 357,250 289,013 230,007

Noise Costs 7,666,300 (kmiles) 5,366 4,341 3,455

Crash Costs 7,666,300 (kmiles) 192,424 155,670 123,888

CO2 -23 (mmT) -199,178 -156,241 -120,625

CO 84,710 (tons) 0 0 0

VOC 1,859 (tons) 3,161 2,062 1,256

NOX -3,552 (tons) -13,852 -12,277 -10,642

PM -500 (tons) -81,980 -66,292 -52,737

SOX -3,382 (tons) -54,105 -43,771 -34,834

Total -6,095,848 -4,918,579 -3,909,004
VIII-45

 Table VIII-12 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2012, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -5,478,272 (kgal) -10,868,471 -8,754,164 -6,941,594

Consumer 

Surplus from 

Additional 

Driving 17,399,527 (kmiles) -1,327,696 -1,071,130 -850,722

Refueling Time 

Value -20,525,226 (hours) -492,605 -398,516 -317,152

Petroleum 

Market 

Externalities -5,478,272 (kgal) -1,533,724 -1,240,776 -987,452

Congestion 

Costs 17,399,527 (kmiles) 810,818 655,948 522,026

Noise Costs 17,399,527 (kmiles) 12,180 9,853 7,842

Crash Costs 17,399,527 (kmiles) 436,728 353,311 281,177

CO2 -53 (mmT) -461,762 -362,219 -279,649

CO 761,706 (tons) 0 0 0

VOC 18,561 (tons) 31,554 21,119 13,250

NOX 17,083 (tons) 66,622 37,737 16,756

PM -1,523 (tons) -249,839 -201,709 -160,269

SOX -8,040 (tons) -128,642 -104,069 -82,820

Total -13,704,838 -11,054,616 -8,778,608
VIII-46

 Table VIII-13 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2013, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -8,508,804 (kgal) -16,796,650 -13,508,492 -10,688,849

Consumer 

Surplus from 

Additional 

Driving 27,188,329 (kmiles) -2,054,826 -1,655,395 -1,312,269

Refueling Time 

Value -32,253,023 (hours) -774,073 -626,221 -498,368

Petroleum 

Market 

Externalities -8,508,804 (kgal) -2,382,167 -1,927,162 -1,533,702

Congestion 

Costs 27,188,329 (kmiles) 1,266,976 1,024,978 815,712

Noise Costs 27,188,329 (kmiles) 19,032 15,397 12,253

Crash Costs 27,188,329 (kmiles) 682,427 552,080 439,364

CO2 -82 (mmt) -730,569 -573,079 -442,442

CO 734,617 (tons) 0 0 0

VOC 17,081 (tons) 29,037 19,409 12,103

NOX 9,106 (tons) 35,513 13,286 -2,256

PM -2,232 (tons) -366,080 -295,685 -235,000

SOX -12,319 (tons) -197,096 -159,448 -126,893

Total -21,268,476 -17,120,333 -13,560,347
VIII-47

 Table VIII-14 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2014, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -9,391,857 (kgal) -18,376,166 -14,768,243 -11,671,696

Consumer 

Surplus from 

Additional 

Driving 30,130,353 (kmiles) -2,265,105 -1,823,071 -1,443,287

Refueling Time 

Value -35,503,043 (hours) -852,073 -689,323 -548,587

Petroleum 

Market 

Externalities -9,391,857 (kgal) -2,629,391 -2,127,165 -1,692,871

Congestion 

Costs 30,130,353 (kmiles) 1,404,074 1,135,890 903,980

Noise Costs 30,130,353 (kmiles) 21,091 17,063 13,579

Crash Costs 30,130,353 (kmiles) 756,272 611,820 486,908

CO2 -89 (mmT) -812,842 -637,617 -492,268

CO -5,658 (tons) 0 0 0

VOC -1,090 (tons) -1,853 -2,068 -2,182

NOX -9,088 (tons) -35,445 -36,431 -35,546

PM -2,786 tons) -456,882 -367,050 -290,218

SOX -13,876 (tons) -222,024 -179,614 -142,941

Total -23,470,345 -18,865,810 -14,915,129
VIII-48

 Table VIII-15 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2015, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -10,195,498 (kgal) -19,973,909 -16,040,212 -12,660,941

Consumer 

Surplus from 

Additional 

Driving 32,977,172 (kmiles) -2,454,647 -1,974,101 -1,560,979

Refueling Time 

Value -38,972,327 (hours) -935,336 -756,682 -602,194

Petroleum 

Market 

Externalities -10,195,498 (kgal) -2,854,383 -2,309,182 -1,837,726

Congestion 

Costs 32,977,172 (kmiles) 1,536,736 1,243,213 989,391

Noise Costs 32,977,172 (kmiles) 23,084 18,675 14,862

Crash Costs 32,977,172 (kmiles) 827,727 669,627 532,912

CO2 -96 (mmT) -902,032 -707,580 -546,283

CO -99,460 (tons) 0 0 0

VOC -3,380 (tons) -5,745 -4,895 -4,158

NOX -13,408 (tons) -52,290 -48,866 -44,507

PM -3,048 (tons) -499,947 -401,659 -317,517

SOX -15,050 (tons) -240,797 -194,802 -155,028

Total -25,531,539 -20,506,465 -16,192,169
VIII-49

 Table VIII-16 

 Lifetime Monetized Societal Impacts, 

 Optimized CAFE, MY 2011-2015, Light Trucks 

 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -35,978,042 (kgal) -70,826,579 -56,954,337 -45,050,444

Consumer 

Surplus from 

Additional 

Driving 115,361,681 (kmiles) -8,697,686 -7,004,965 -5,550,419

Refueling Time 

Value -136,637,500 (hours) -3,279,300 -2,652,939 -2,111,299

Petroleum 

Market 

Externalities -35,978,042 (kgal) -10,072,593 -8,148,681 -6,485,000

Congestion 

Costs 115,361,681 (kmiles) 5,375,854 4,349,041 3,461,116

Noise Costs 115,361,681 (kmiles) 80,753 65,329 51,991

Crash Costs 115,361,681 (kmiles) 2,895,578 2,342,509 1,864,249

CO2 -343 (mmT) -3,106,382 -2,436,737 -1,881,267

CO 1,475,915 (tons) 0 0 0

VOC 33,031 (tons) 56,154 35,627 20,269

NOX 141 (tons) 548 -46,551 -76,195

PM -10,090 (tons) -1,654,728 -1,332,395 -1,055,741

SOX -52,667 (tons) -842,664 -681,704 -542,517

Total -90,071,046 -72,465,802 -57,355,257
VIII-50

Table VIII-17 

 Lifetime Monetized Societal Impacts, 

Optimized CAFE, MY 2011-2015, Passenger Cars and Light Trucks 

Societal Effect Physical 

Units 

Undiscounted 

Value (2006$ k) 

Present 

Discounted Value 

@ 3% 

Present Discounted 

Value @ 7% 

Lifetime Fuel 

Expenditures -54,713,652 (kgal) -107,464,331 -85,413,628 -69,880,983

Consumer 

Surplus from 

Additional 

Driving 189,986,006 (kmiles) -13,212,451 -10,512,659 -8,618,003

Refueling Time 

Value -231,455,155 (hours) -5,554,924 -4,427,668 -3,666,008

Petroleum 

Market 

Externalities -54,713,652 (kgal) -15,317,908 -12,239,283 -10,068,605

Congestion 

Costs 189,986,006 (kmiles) 9,271,244 7,387,107 6,122,451

Noise Costs 189,986,006 (kmiles) 132,990 106,069 87,679

Crash Costs 189,986,006 (kmiles) 4,582,088 3,657,841 3,016,475

CO2 -521 (mmT) -4,659,516 -3,627,693 -2,906,044

CO 754,337 (tons) 0 0 0

VOC 20,261 (tons) 34,444 20,001 8,109

NOX -55,549 (tons) -216,641 -212,298 -217,540

PM -13,151 (tons) -2,156,735 -1,717,706 -1,385,402

SOX -79,225 (tons) -1,267,599 -1,013,099 -832,832

Total -135,829,336 -107,993,015 -88,340,704
VIII-51

Table VIII-18 

Savings in Millions of Gallons of Fuel 

Undiscounted, over the Lifetime of the Model Year Fleet 

Passenger Cars 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

708 1261 1946 3135 4151 11201 

Optimized Net 

Impact -7% 

1563 2968 3717 4771 5716 18735 

25% Above 

Optimized 

2313 4480 5221 6601 7476 26091 

50% Above 

Optimized 

2641 5523 6422 7913 9121 31620 

Optimized Net 

Impact -3% 

3463 6197 6905 8587 9784 34936 

TC=TB 3599 6860 7676 9320 10461 37916 

Technology 

Exhaustion 

3677 7143 8261 10233 11562 40876 

Table VIII-19 

Savings in Millions of Gallons of Fuel 

Undiscounted, over the Lifetime of the Model Year Fleet 

Light Trucks 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

2157 4933 7902 7799 7808 30599 

Optimized Net 

Impact -7% 

2404 5478 8509 9392 10195 35978 

25% Above 

Optimized 

2585 6339 9070 10592 12534 41120 

50% Above 

Optimized 

2909 6780 9697 11458 13584 44428 

Optimized Net 

Impact -3% 

2414 5488 8978 9959 11127 37966 

TC = TB 3228 7471 10640 12778 14602 48719 

Technology 

Exhaustion 

3263 7506 12659 14448 16147 54023 
VIII-52

Table VIII-20 

Savings in Millions of Gallons of Fuel 

Undiscounted, over the Lifetime of the Model Year Fleet 

Passenger Cars and Light Trucks 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

2865 6194 9848 10934 11959 41800 

Optimized Net 

Impact -7% 

3967 8446 12226 14163 15911 54713 

25% Above 

Optimized 

4898 10819 14291 17193 20010 67211 

50% Above 

Optimized 

5550 12303 16119 19371 22705 76048 

Optimized Net 

Impact -3% 

5877 11685 15883 18546 20911 72902 

TC = TB 6827 14331 18316 22098 25063 86635 

Technology 

Exhaustion 

6940 14649 20920 24681 27709 94899 

Table VIII-21 

Present Value @3% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Passenger Cars 

 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

1418 2581 3977 6399 8387 22762 

Optimized Net 

Impact-7% 

3181 6054 7561 9716 11616 38128 

25% Above 

Optimized 

4604 8939 10403 13109 14907 51962 

50% Above 

Optimized 

5241 10842 12571 15503 17893 62050 

Optimized Net 

Impact -3% 

6798 12188 13519 16833 19216 68554 

TC = TB 7075 13366 14881 18059 20364 73745 

Technology 

Exhaustion 

7156 13865 15967 19654 22312 78954 
VIII-53

Table VIII-22 

Present Value @3% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Light Trucks 

 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

4414 9959 15910 15715 15745 61743 

Optimized Net 

Impact -7% 

4919 11055 17120 18866 20506 72466 

25% Above 

Optimized 

5286 12599 17972 20984 24662 81503 

50% Above 

Optimized 

5848 13249 18955 22375 26475 86902 

Optimized Net 

Impact -3% 

4939 11075 17976 19902 22246 76138 

TC = TB 6343 14452 20631 24704 28352 94482 

Technology 

Exhaustion 

6420 14528 24517 27951 31387 104803 

Table VIII-23 

Present Value @3% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Passenger Cars and Light Trucks 

 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

5832 12540 19887 22114 24132 84505 

Optimized Net 

Impact -7% 

8100 17109 24681 28582 32122 110594 

25% Above 

Optimized 

9890 21538 28375 34093 39569 133465 

50% Above 

Optimized 

11089 24091 31526 37878 44368 148952 

Optimized Net 

Impact -3% 

11737 23263 31495 36735 41462 144692 

TC = TB 13418 27818 35512 42763 48716 168227 

Technology 

Exhaustion 

13576 28393 40484 47605 53699 183757 
VIII-54

Table VIII-24 

Present Value @7% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Passenger Cars 

 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

1156 2104 3235 5197 6799 18491 

Optimized Net 

Impact -7% 

2596 4933 6148 7889 9420 30986 

25% Above 

Optimized 

3755 7280 8454 10638 12083 42210 

50% Above 

Optimized 

4274 8825 10213 12576 14495 50383 

Optimized Net 

Impact -3% 

5543 9922 10983 13654 15569 55671 

TC=TB 5769 10878 12087 14644 16492 59870 

Technology 

Exhaustion 

5834 11282 12968 15930 18061 64075 

Table VIII-25 

Present Value @7% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Light Trucks 

 

MY 

2011

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

3508 7910 12603 12432 12441 48894 

Optimized Net 

Impact - 7% 

3909 8779 13560 14915 16192 57355 

25% Above 

Optimized 

4201 9990 14236 16587 19457 64471 

50% Above 

Optimized 

4642 10507 15011 17687 20892 68739 

Optimized Net 

Impact -3% 

3926 8794 14251 15752 17589 60312 

TC = TB 5027 11453 16330 19515 22367 74692 

Technology 

Exhaustion 

5088 11513 19395 22074 24759 82829 
VIII-55

Table VIII-26 

Present Value @7% Discount Rate of Lifetime Social Benefits 

(Millions of 2006 Dollars), Passenger Cars and Light Trucks 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

All 5 

MYs 

25% Below 

Optimized 

4664 10014 15838 17629 19240 67385 

Optimized Net 

Impact -7% 

6505 13712 19708 22804 25612 88341 

25% Above 

Optimized 

7956 17270 22690 27225 31540 106681 

50% Above 

Optimized 

8916 19332 25224 30263 35387 119122 

Optimized Net 

Impact -3% 

9469 18716 25234 29406 33158 115983 

TC = TB 10796 22331 28417 34159 38859 134562 

Technology 

Exhaustion 

10922 22795 32363 38004 42820 146904 
VIII-56

References 

Argonne National Laboratories, The Greenhouse Gas and Regulated Emissions from 

Transportation (GREET) Model, Version 1.6, February 2002. 

Greene, David L., “Vehicle Use and Fuel Economy: How Big is the Rebound Effect?” The 

Energy Journal, 13:1 (1992), 117-143. 

Greene, David L., Donald W. Jones, and Paul N. Leiby, The Outlook for U.S. Oil Dependence, 

ORNL-6873, Oak Ridge National Laboratory, May 11, 1995. 

Greene, David L., James R. Kahn, and Robert C. Gibson, “Fuel Economy Rebound Effect for 

Household Vehicles,” The Energy Journal, 20:3 (1999), 1-31. 

Greene, David L., and Nataliya I. Tishchishyna, Costs of Oil Dependence: A 2000 Update, 

ORNL/TM-2000/152, Oak Ridge National Laboratory, May 2000. 

Haughton, Jonathan, and Soumodip Sarkar, “Gasoline Tax as a Corrective Tax: Estimates for the 

United States,” The Energy Journal, 17:2, 103-126. 

Jones, Clifton T., “Another Look at U.S. Passenger Vehicle Use and the ‘Rebound’ Effect from 

Improved Fuel Efficiency, The Energy Journal, 14:4 (1993), 99-110. 

Leiby, Paul N., Donald W. Jones, T. Randall Curlee, and Russell Lee, Oil Imports: An 

Assessment of Benefits and Costs, ORNL-6851, Oak Ridge National Laboratory, November 1, 

1997. 

Pickrell, Don H., “Description of VMT Forecasting Procedure for ‘Car Talk’ Base line 

Forecasts,” manuscript, Volpe National Transportation Systems Center, U.S. Department of 

Transportation, 1994. 

Puller, S.L., and L.A. Greening, “Household Adjustment to Gasoline Price Changes: An 

Analysis Using Nine Years of U.S. Survey Data,” Energy Economics, 21:1, pp. 37-52. 

Small, K.A. and VanDender, K. (2005) “A Study to Evaluate the Effect of Reduced Greenhouse 

Gas Emissions on Vehicle Miles Traveled”, State of California Air Resources Board, California 

Environmental Protection Agency, and the California Energy Commission. 

U.S. Department of Energy, Program Analysis Methodology Office of Transportation 

Technology: Quality Metrics 2002, Final Report, Office of Transportation Technologies, May 9, 

2001. 

U.S. Environmental Protection Agency, MOBILE Motor Vehicle Emission Factor Model, 

version 6.2, November 2002. 
IX-1

IX. NET BENEFITS AND SENSITIVITY ANALYSES 

This chapter compares the costs of technologies needed to make improvements in fuel economy 

to meet the alternatives with the potential benefits, expressed in total costs (millions of dollars) 

for each model year. The costs do not include fines, since these are transfer payments. Thus, 

the total costs shown in this section do not match the total costs shown in Chapter VII. The 

following tables combine the estimated costs and benefits from a societal perspective. These are 

incremental costs and benefits compared to an adjusted baseline of manufacturers’ production 

plans. Tables utilizing a 3 percent and 7 percent discount rate for benefits are presented. 

Sensitivity analyses are also performed on some of the assumptions made in this analysis. 

Finally, a payback period is calculated, from the consumer’s perspective. 

Table IX-1 provides the total incremental costs (in millions of dollars) from a societal 

perspective. Table IX-2a and Table IX-2b provide the total benefits at a 3 percent and 7 percent 

discount rate from a societal perspective for all vehicles produced during each model year to 

which the standard is applicable. Table IX-3a and Table IX-3b show the total net benefits in 

millions of dollars at a 3 percent and 7 percent discount rate for the projected fleet of sales for 

each model year. 
IX-2

Table IX-1 

Incremental Total Cost (excludes fines) 

(Millions of 2006 Dollars) 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Total 5 

years 

Passenger 

Cars 

25% Below 

Optimized 835 818 1,253 2,153 3,209 8,268 

Optimized 

(7%) 1,884 2,373 2,879 3,798 4,862 15,796 

25% Above 

Optimized 3,387 5,653 6,445 8,240 9,084 32,808 

50% Above 

Optimized 4,010 7,885 8,986 11,207 12,981 45,070 

Optimized 

(3%) 5,467 8,791 9,821 12,447 14,484 51,011 

TC = TB 5,913 10,796 12,303 15,403 17,398 61,812 

Technology 

Exhaustion 6,079 12,595 14,701 18,759 21,110 73,245 

 

Light Trucks 

25% Below 

Optimized 1,349 4,296 6,329 6,212 6,326 24,512 

Optimized 

(7%) 1,649 4,986 7,394 8,160 8,761 30,949 

25% Above 

Optimized 2,072 7,034 9,815 11,903 14,781 45,606 

50% Above 

Optimized 2,922 8,098 11,586 14,386 17,969 54,961 

Optimized 

(3%) 1,662 4,974 8,190 9,058 10,253 34,136 

TC = TB 3,788 10,525 15,196 18,762 21,364 69,635 

Technology 

Exhaustion 3,933 10,670 18,275 21,051 23,479 77,408 

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 2,184 5,114 7,582 8,365 9,534 32,780 

Optimized 

(7%) 3,534 7,358 10,273 11,957 13,623 46,745 

25% Above 

Optimized 5,459 12,687 16,261 20,143 23,865 78,414 

50% Above 

Optimized 6,932 15,983 20,572 25,593 30,950 100,030 

Optimized 

(3%) 7,128 13,765 18,011 21,505 24,737 85,147 

TC = TB 9,702 21,321 27,499 34,164 38,761 131,447 

Technology 

Exhaustion 10,013 23,266 32,976 39,810 44,589 150,653 
IX-3

Total costs follow a predictable pattern with costs rising to reflect the more expensive 

technologies that manufacturers must apply in order to achieve the CAFE levels that are required 

under the more aggressive alternatives, with the exception of the Optimized (3%) for light trucks. 

For the combined fleet, total compliance costs for the Total Cost = Total Benefit alternative is 

roughly 2.8 times those for the Optimized (7%) alternative over the 5 model years. Relative to 

the proposed Optimized (7%) alternative, Technology exhaustion produces costs that are 3.2 

times the Optimized cost levels. 
IX-4

Table IX-2a 

Present Value of Lifetime Societal Benefits by Alternative 

(Millions of 2006 Dollars) 

 (Discounted 3%) 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Total 5 

years 

Passenger 

Cars 

25% Below 

Optimized 

1,418 2,581 3,977 6,399 8,387 

22,762 

Optimized 

(7%) 

3,181 6,054 7,561 9,716 11,616 

38,128 

25% Above 

Optimized 

4,604 8,939 10,403 13,109 14,907 

51,962 

50% Above 

Optimized 

5,241 10,842 12,571 15,503 17,893 

62,050 

Optimized 

(3%) 

6,798 12,188 13,519 16,833 19,216 

68,554 

TC = TB 7,075 13,366 14,881 18,059 20,364 73,745 

Technology 

Exhaustion 

7,156 13,865 15,967 19,654 22,312 

78,954 

 

Light Trucks 

25% Below 

Optimized 

4,414 9,959 15,910 15,715 15,745 

61,743 

Optimized 

(7%) 

4,919 11,055 17,120 18,866 20,506 

72,466 

25% Above 

Optimized 

5,286 12,599 17,972 20,984 24,662 

81,503 

50% Above 

Optimized 

5,848 13,249 18,955 22,375 26,475 

86,902 

Optimized 

(3%) 

4,939 11,075 17,976 19,902 22,246 

76,138 

TC = TB 6,343 14,452 20,631 24,704 28,352 94,482 

Technology 

Exhaustion 

6,420 14,528 24,517 27,951 31,387 

104,803 

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 5,832 12,540 19,887 22,114 24,132 84,505 

Optimized 

(7%) 8,100 17,109 24,681 28,582 32,122 110,594 

25% Above 

Optimized 9,890 21,538 28,375 34,093 39,569 133,465 

50% Above 

Optimized 11,089 24,091 31,526 37,878 44,368 148,952 

Optimized 

(3%) 11,737 23,263 31,495 36,735 41,462 144,692 

TC = TB 13,418 27,818 35,512 42,763 48,716 168,227 

Technology 

Exhaustion 13,576 28,393 40,484 47,605 53,699 183,757 
IX-5

From Table IX-2a, lifetime societal benefits follow a similar predictable pattern, with higher 

benefits associated with the more expensive technologies that are enabled under the more 

aggressive alternatives. For the combined fleet, the TC=TB alternative produces gross benefits 

roughly 1.5 times as high as the Optimized (7%) alternative, and the Technology exhaustion 

alternative produces gross benefits that are 1.7 times the Optimized (7%) alternative. 

Similar results occur for benefits discounted at the 7% rate (Table IX-2b). However, while the 

pattern for benefits is directionally similar to the pattern for costs, the more aggressive 

technology scenarios do not increase benefits by as high a ratio as they do for costs. For 

example, the TC=TB alternative increases total benefits by $46 billion over the Optimized (7%) 

alternative, but it also increases total costs by $85 billion, a net loss to society of $39 billion. 

This is a function of the more aggressive alternatives relatively unrestrained functions. While 

the Optimized (7%) alternative adds technology until the marginal cost to society begins to 

exceed the marginal benefit, the TC=TB scenario and the Technology exhaustion scenario allow 

for continued investment in technology despite its negative net return. Thus, while both costs 

and benefits continue to rise with more aggressive technologies, the costs rapidly begin to exceed 

the benefits that society derives from the added investment. 
IX-6

 Table IX-2b 

Present Value of Lifetime Societal Benefits by Alternative 

(Millions of 2006 Dollars) 

 (Discounted 7%) 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Total 5 

years 

Passenger 

Car 

 

25% Below 

Optimized 

1,156 2,104 3,235 5,197 6,799 

18,491 

Optimized 

(7%) 

2,596 4,933 6,148 7,889 9,420 

30,986 

25% Above 

Optimized 

3,755 7,280 8,454 10,638 12,083 

42,210 

50% Above 

Optimized 

4,274 8,825 10,213 12,576 14,495 

50,383 

Optimized 

(3%) 

5,543 9,922 10,983 13,654 15,569 

55,671 

TC = TB 5,769 10,878 12,087 14,644 16,492 59,870 

Technology 

Exhaustion 

5,834 11,282 12,968 15,930 18,061 

64,075 

 

Light Trucks 

25% Below 

Optimized 

3,508 7,910 12,603 12,432 12,441 

48,894 

Optimized 

(7%) 

3,909 8,779 13,560 14,915 16,192 

57,355 

25% Above 

Optimized 

4,201 9,990 14,236 16,587 19,457 

64,471 

50% Above 

Optimized 

4,642 10,507 15,011 17,687 20,892 

68,739 

Optimized 

(3%) 

3,926 8,794 14,251 15,752 17,589 

60,312 

TC = TB 5,027 11,453 16,330 19,515 22,367 74,692 

Technology 

Exhaustion 

5,088 11,513 19,395 22,074 24,759 

82,829 

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 4,664 10,014 15,838 17,629 19,240 67,385 

Optimized 

(7%) 6,505 13,712 19,708 22,804 25,612 88,341 

25% Above 

Optimized 7,956 17,270 22,690 27,225 31,540 106,681 

50% Above 

Optimized 8,916 19,332 25,224 30,263 35,387 119,122 

Optimized 

(3%) 9,469 18,716 25,234 29,406 33,158 115,983 

TC = TB 10,796 22,331 28,417 34,159 38,859 134,562 

Technology 

Exhaustion 10,922 22,795 32,363 38,004 42,820 146,904 
IX-7

Table IX-3a 

Net Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

(Millions of 2006 Dollars)* 

(Discounted 3%) 

Passenger 

Cars 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Total 5 

years 

25% Below 

Optimized 583 1,763 2,724 4,246 5,178 14,494 

Optimized 

(7%) 1,297 3,681 4,682 5,918 6,754 22,332 

25% Above 

Optimized 1,217 3,286 3,958 4,869 5,823 19,154 

50% Above 

Optimized 1,231 2,957 3,585 4,296 4,912 16,980 

Optimized 

(3%) 1,331 3,397 3,698 4,386 4,732 17,543 

TC = TB 1,162 2,570 2,578 2,656 2,966 11,933 

Technology 

Exhaustion 1,077 1,270 1,266 895 1,202 5,709 

 

Light Trucks 

25% Below 

Optimized 3,065 5,663 9,581 9,503 9,419 37,231 

Optimized 

(7%) 3,270 6,069 9,726 10,706 11,745 41,517 

25% Above 

Optimized 3,214 5,565 8,157 9,081 9,881 35,897 

50% Above 

Optimized 2,926 5,151 7,369 7,989 8,506 31,941 

Optimized 

(3%) 3,277 6,101 9,786 10,844 11,993 42,002 

TC = TB 2,555 3,927 5,435 5,942 6,988 24,847 

Technology 

Exhaustion 2,487 3,858 6,242 6,900 7,908 27,395 

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 3,648 7,426 12,305 13,749 14,598 51,725 

Optimized 

(7%) 4,566 9,751 14,408 16,625 18,499 63,849 

25% Above 

Optimized 4,431 8,851 12,114 13,950 15,704 55,051 

50% Above 

Optimized 4,157 8,108 10,954 12,285 13,418 48,922 

Optimized 

(3%) 4,609 9,498 13,484 15,230 16,725 59,545 

TC = TB 3,716 6,497 8,013 8,599 9,955 36,780 

Technology 

Exhaustion 3,563 5,127 7,508 7,795 9,110 33,104 
IX-8

 

The impact of the relatively unrestricted technology application that is enabled by the more 

aggressive scenarios is apparent from Tables IX-3a and IX-3b, which show net total lifetime 

societal benefits under each alternative. Across all 5 model years the Optimized (7%) or the 

Optimized (3%) alternative produces the highest net total benefits to society, as would be 

expected. Under a 3% discount rate, net benefits produced by the Optimized (7%) alternative 

exceed those produced by the TC = TB alternative by an extra $27 billion, and exceed those 

produced under the Technology Exhaustion alternative by $30 billion. Under the 7% discount 

rate, the Technology exhaustion alternative produces a net loss to society of over $3.7 billion. 
IX-9

 Table IX-3b 

Net Total Benefits 

Over the Vehicle’s Lifetime – Present Value 

(Millions of 2006 Dollars) 

(Discounted 7%) 

Passenger 

Cars 

MY 

2011 

MY 

2012 

MY 

2013 

MY 

2014 

MY 

2015 

Total 5 

years 

25% Below 

Optimized 321 1,286 1,982 3,044 3,590 10,223 

Optimized 

(7%) 712 2,560 3,269 4,091 4,558 15,190 

25% Above 

Optimized 368 1,627 2,009 2,398 2,999 9,402 

50% Above 

Optimized 264 940 1,227 1,369 1,514 5,313 

Optimized 

(3%) 76 1,131 1,162 1,207 1,085 4,660 

TC = TB -144 82 -216 -759 -906 -1,942 

Technology 

Exhaustion -245 -1,313 -1,733 -2,829 -3,049 -9,170 

 

Light Trucks 

25% Below 

Optimized 2,159 3,614 6,274 6,220 6,115 24,382 

Optimized 

(7%) 2,260 3,793 6,166 6,755 7,431 26,406 

25% Above 

Optimized 2,129 2,956 4,421 4,684 4,676 18,865 

50% Above 

Optimized 1,720 2,409 3,425 3,301 2,923 13,778 

Optimized 

(3%) 2,264 3,820 6,061 6,694 7,336 26,176 

TC = TB 1,239 928 1,134 753 1,003 5,057 

Technology 

Exhaustion 1,155 843 1,120 1,023 1,280 5,421 

 

Passenger Cars and Light Trucks Combined 

25% Below 

Optimized 2,480 4,900 8,256 9,264 9,706 34,605 

Optimized 

(7%) 2,971 6,354 9,435 10,847 11,989 41,596 

25% Above 

Optimized 2,497 4,583 6,429 7,082 7,675 28,267 

50% Above 

Optimized 1,984 3,349 4,652 4,670 4,437 19,092 

Optimized 

(3%) 2,341 4,951 7,223 7,901 8,421 30,836 

TC = TB 1,094 1,010 918 -5 98 3,115 

Technology 

Exhaustion 909 -471 -613 -1,806 -1,769 -3,749 
IX-10

Sensitivity Analyses 

The agency has performed several sensitivity analyses to examine important assumptions. The 

analyses include: 

1) The value of CO2. We examined a range from $0 per metric ton to $14 per metric ton, 

with the main analysis using a value of $7.50 per metric ton. These values can be 

translated into a value for carbon by multiplying by a factor of 3.66, or can be translated 

into cents per gallon by multiplying by 0.0089209, as shown below: 

$7.50 per ton CO2 = $7.50*3.667 = $27.50 per ton C = $7.50*0.0089 = $0.06675 per gallon 

$14.00 per ton CO2 = $14.00*3.667 = $51.34 per ton C = $14.00*0.0089 = $0.1246 per gallon 

2) The value of externalities. The main analysis uses $0.295 per gallon for externalities. 

The sensitivity analysis examines $0.120 and $0.504 per gallon. 

3) The price of gasoline. The main analysis uses the AEO 2008 reference case estimate for 

the price of gasoline. The preliminary AEO 2008 estimate does not contain a high price 

or low price of gasoline case. We assumed for this analysis an estimate of the AEO 2008 

high price and low price for gasoline (based on applying the percentage increase between 

the high price estimate and the reference case estimate in the AEO 2007 forecast to the 

AEO 2008 reference case estimate). 

4) The rebound effect. The main analysis uses a rebound effect of 15 percent. The 

sensitivity analysis examines rebound effects of 10 percent and 20 percent. 

Sensitivity analyses were performed on just the optimized (7%) alternative. Presented are 

information on the average mpg expected by model year, the price per vehicle increase for MY 

2015, total benefits for MY 2015 vehicles, the total cost increase for MY 2015, the total fuel 

saved (all 5 model years combined) and the total CO2 emissions reduction (all 5 model years 

combined). 

The results of the sensitivity analyses indicate that the value of CO2, the value of externalities, 

and the value of the rebound effect have almost no impact on the level of the standards. 

Assuming a higher price of gasoline has the largest impact of the sensitivity analyses examined 

(raising the MY 2015 passenger car standard level by 6.7 mpg and the light truck level by 0.8 

mpg). It appears that the light truck levels are not as sensitive as the passenger car levels to 

changes in the estimated benefits. This can occur because the technologies that have not been 

used under the Optimized alternative, and are still available for light trucks, are not that close to 

being cost effective and it takes a larger increase in benefits to bring them over the cost-benefit 

threshold. 

 

209 The molecular weight of Carbon (C) is 12, the molecular weight of Oxygen (O) is 16, thus the molecular weight of 

CO2 is 44. One ton of C = 44/12 tons CO2 = 3.67 tons CO2. 1 gallon of gas weighs 2,819 grams, of that 2,433 grams 

are carbon. $1.00 CO2 = $3.67 C and 

$3.67/ton * ton/1000kg * kg/1000g * 2433g/gallon = (3.67 * 2433) / 1000 * 1000 = $0.0089/gallon 
IX-11

Note that there are some slight inconsistencies in the relationships one would expect when 

comparing the required mpg levels for corresponding model years in the various sensitivity 

analyses to those under the proposed CAFE standards. For example, the level of the standard 

should increase when CO2 is assigned a higher value, because this increases the benefit of each 

gallon of fuel saved, but the optimized standards for some model years are actually lower with 

the high CO2 value than under the proposal. Problems such as this arise when making slight 

changes in parameter values used by the CAFE model, since the model derives a relationship 

between net benefits and the stringency level of standards for each model year, and minor 

changes in parameter values can affect the exact shapes and positions of those curves. In any 

case, the seemingly anomalous results are mostly small (0.1 mpg or less), and are sometimes the 

result of rounding. When larger variations are made to the model’s parameters or other inputs, 

such as substituting EIA’s High gasoline price forecast for the Reference Case forecast, the 

sensitivity analysis invariable produces the anticipated result. 
IX-12

Table IX-5a 

Passenger Car Sensitivity Analyses 

(mpg) 

Optimized MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

Proposal 31.2 32.8 34.0 34.8 35.7 

Low CO2 31.2 32.7 33.8 34.7 35.3 

High CO2 31.2 32.7 33.8 34.6 35.7 

Low 

Externalities 

31.2 32.8 33.9 34.7 35.4 

High 

Externalities 

31.1 32.7 34.1 34.9 36.0 

Low Fuel 

Price 

31.1 32.8 33.8 34.7 35.9 

High Fuel 

Price 

37.4 38.9 40.4 41.3 42.4 

10% Rebound 31.1 32.7 33.9 34.6 36.0 

20% Rebound 31.2 32.8 33.8 34.8 35.7 

Optimized MY 2015 MY 2015 MY 2015 

Per Vehicle 

Cost Total Benefits Total Cost 

Total Fuel 

Saved 

Total CO2 

Emissions 

Reduced 

 ($) ($ Mill.) ($ Mill.) (Bill. Gal.) (mmt) 

Proposal 649 9,420 4,862 18.736 178 

Low CO2 571 8,583 4,263 18.129 173 

High CO2 633 9,655 4,731 18.351 174 

Low 

Externalities 

596 8,340 4,458 18.307 175 

High 

Externalities 

715 10,660 5,367 19.276 182 

Low Fuel 

Price 

675 8,273 5,014 18.446 171 

High Fuel 

Price 

2,081 24,622 15,477 36.686 319 

10% Rebound 714 10,343 5,346 19.730 186 

20% Rebound 644 8,833 4,811 17.738 169 
IX-13

Table IX-5b 

Light Truck Sensitivity Analyses 

(mpg) 

Optimized MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

Proposal 25.0 26.4 27.8 28.2 28.6 

Low CO2 25.0 26.4 27.7 28.2 28.6 

High CO2 25.0 26.4 27.7 28.1 28.6 

Low 

Externalities 

25.1 25.4 27.2 27.9 28.2 

High 

Externalities 

25.0 26.4 27.8 28.2 28.8 

Low Fuel 

Price 

25.1 25.2 26.9 27.6 28.2 

High Fuel 

Price 

25.1 26.7 28.1 28.6 29.4 

10% Rebound 25.0 26.4 27.7 28.1 28.6 

20% Rebound 25.0 26.4 27.8 28.2 28.7 

Optimized MY 2015 MY 2015 MY 2015 

Per Vehicle 

Cost Total Benefits Total Cost 

Total Fuel 

Saved 

Total CO2 

Emissions 

Reduced 

 ($) ($ Mill.) ($ Mill.) (Bill. Gal.) (mmt) 

Proposal 979 16,192 8,761 35.978 343 

Low CO2 966 15,543 8,646 35.752 340 

High CO2 943 16,587 8,434 35.564 339 

Low 

Externalities 

775 13,874 6,927 31.927 304 

High 

Externalities 

1,025 18,001 9,172 36.331 346 

Low Fuel 

Price 

789 12,887 7,054 30.054 285 

High Fuel 

Price 

1,393 27,647 12,468 40.115 376 

10% Rebound 943 16,839 8,434 37.262 355 

20% Rebound 997 15,603 8,924 34.403 327 
IX-14

Payback Period 

The “payback period” represents the length of time required for a vehicle buyer to recoup, 

through savings in fuel use, the higher cost of purchasing a more fuel-efficient vehicle. Thus, 

only these two factors are considered (purchase price and fuel savings). When a higher CAFE 

standard requires a manufacturer to improve the fuel economy of some of its vehicle models, the 

manufacturer’s added costs for doing so are reflected in higher prices for these models. While 

buyers of these models pay higher prices to purchase these vehicles, their improved fuel 

economy lowers the consumer’s costs for purchasing fuel to operate them. Over time, buyers 

may recoup the higher purchase prices they pay for these vehicles in the form of savings in 

outlays for fuel. The length of time required to repay the higher cost of buying a more fuelefficient vehicle is referred to as the buyer’s payback period. 

The length of this payback period depends on the initial increase in a vehicle’s purchase price, 

the improvement in its fuel economy, the number of miles it is driven each year, and the retail 

price of fuel. We calculated payback periods using the fuel economy improvement and average 

price increase estimated to result from the standard, the future retail gasoline prices, and 

estimates of the number of miles vehicles are driven each year as they age. These calculations 

are taken from a consumer’s perspective, not a societal perspective. Thus, only gasoline savings 

are included on the benefits side of the equation. The price of gasoline includes fuel taxes and 

future savings are not discounted to present value, since consumers generally only consider and 

respond to what they pay at the pump. The payback periods was estimated for only MY 2015 

vehicles and an average of all manufacturers for the different alternatives. The payback periods 

for MY 2015 are shown in Table IX-10. 

Table IX-10 

Payback Period for MY 2015 Average Vehicles 

(in years) 

 

Passenger 

Cars 

Light 

Trucks 

25% Below 

Optimized 4.3 3.9

Optimized 

(7%) 4.7 4.2

25% Above 

Optimized 6.7 6.0

50% Above 

Optimized 8.3 7.0

Optimized 

(3%) 8.8 4.5

TC = TB 10.4 8.3

Technology 

Exhaustion Never 8.3
X-1

X. PROBABILISTIC UNCERTAINTY ANALYSIS 

OMB Circular A-4 requires formal probabilistic uncertainty analysis of complex rules where 

there are large, multiple uncertainties whose analysis raises technical challenges or where effects 

cascade and where the impacts of the rule exceed $1 billion. CAFE meets all of these criteria. 

This chapter identifies and quantifies the major uncertainties in the preliminary regulatory impact 

analysis and estimates the probability distribution of the benefits, costs, and net benefits of the 

compliance options selected for the proposed rule for MY 2011-2015 passenger car and light 

truck CAFE standards. Throughout the course of the main analysis, input values were selected 

from a variety of often conflicting sources. Best estimates were selected based on the 

preponderance of data and analyses available, but there is inevitably a level of uncertainty in 

these selections. Some of these inputs contributed less to the overall variations of the outcomes, 

and, thus, are less significant. Some inputs depend on others or are closely related (e.g. oil 

import externalities), and thus can be combined. With the vast number of uncertainties 

imbedded in this regulatory analysis, this uncertainty analysis identifies only the major 

independent uncertainty factors having appreciable variability and impact on the end results and 

quantifies them by their probability distributions. These newly defined values are then randomly 

selected and fed back into the model to determine the net benefits using the Monte Carlo 

statistical simulation technique.210 The simulation technique induces the probabilistic outcomes 

accompanied with degrees of probability or plausibility. This facilitates a more informed 

decision-making process. 

The analysis is based on the actual processes used to derive net benefits as described in the 

previous chapters. Each variable (e.g., cost of technology) in the mathematical model represents 

an uncertainty factor that would potentially alter the modeling outcomes if its value was 

changed. We assume that these variables are independent of each other. The confidence 

intervals around the costs and benefits of technologies reflect independent levels of uncertainty 

regarding costs and benefits, rather than linked probabilities dependent on higher or lower 

quality versions of a specific technology. By contrast, there is reason to believe that monopsony 

costs may be dependent on fuel prices. However, monopsony costs are only one of several oil 

import externalities, and the range of monopsony costs is quite narrow. The potential for 

significant error due to an assumption of independence for monopsony costs is thus quite low. 

Given this, the agency has elected to treat monopsony costs as an independent variable. 

 The uncertainties of these variables are described by appropriate probability distribution 

functions based on available data. If data are not sufficient or not available, professional 

judgments are used to estimate the probability distributions of these uncertainty factors. A 

complete description of the formulas and methods used in the CAFE model is available in the 

public docket.211 

 

210 See, for example, Morgan, MG, Henrion, M, and Small M, “Uncertainty: A Guide to Dealing with Uncertainty in 

Quantitative Risk and Policy Analysis”, Cambridge University Press, 1990. 211 CAFE Compliance and Effects Modeling System Documentation, Volpe Center, U.S. Dept. of Transportation, 

July 2005, pp. 27-46 and C-22 to C-35. Docket No. NHTSA 21974-2.
X-2

After defining and quantifying the major uncertainty factors, the next step is to simulate the 

model to obtain probabilistic results rather than single-value estimates. In the uncertainty 

analysis, CAFE levels were kept constant; in other words, we did not change the CAFE 

standards for each run based on net benefits. The simulation process was run repeatedly for 

20,000 trials under each discount rate scenario. Each complete run is a trial. For each trial, the 

simulation first randomly selects a value for each of the uncertainty factors based on their 

probability distributions. The selected values are then fit into the models to forecast results. In 

addition to the simulation results, the program also estimates the degree of certainty (or 

confidence, credibility). The degree of certainty provides the decision-maker with an additional 

piece of important information with which to evaluate the forecast results. 

Simulation Models and Uncertainty Factors 

A Monte Carlo simulation was conducted using the CAFE modeling system that was developed 

to estimate the impacts of higher CAFE requirements described in previous chapters. The focus 

of the simulation model was variation around the chosen uncertainty parameters and their 

resulting impact on the key output parameters, fuel savings, and net benefits. Net benefits 

measure the difference between (1) the total dollar value that would be saved in fuel and other 

benefits and (2) the total costs of the rule. 

The agency reviewed the inputs and relationships that drive the CAFE model to determine the 

factors that are the major sources of uncertainty. Five factors were identified as contributing the 

most uncertainty to the estimated impacts of higher CAFE standards: 

(1) Technology costs; 

(2) Technology effectiveness; 

(3) Fuel prices; 

(4) The value of oil consumption externalities; and 

(5) The rebound effect. 

Technology Costs 

The costs incurred by manufacturers to modify their vehicles to meet new CAFE levels are 

assumed to be passed on to consumers in the form of higher new car prices. These technology 

costs are the primary determinant of the overall cost of improving fuel economy. 

Forty-one different technologies were examined as possible methods to comply with higher 

CAFE standards. These technologies were summarized in Chapter V earlier in this analysis. 

Chapter V also summarizes the estimated range of costs for these technologies. The expected 

values (mid-range values) were used in the main analysis. For the uncertainty analysis, the full 

range of NAS cost estimates is used. The uncertainty model assumes a normal distribution for 

these costs, with each end of the range being three standard deviations from the mean (or 

expected) value. Figure X-1 graphically demonstrates the distributions of a hypothetical sample 

of three of the technologies. 
X-3

Figure X-1 

Normal Distributions for 3 Different Technologies 

-

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0 50 100 150 200 250 300

Retail Price Equivalent Increase ($)

Probability Density

Aero. Drag Reduction ($0-146)

Cylinder Deactivation ($116-262)

Engine Acc. Improvement ($87-116)

Technology Effectiveness 

The modifications adopted by manufacturers to enable their vehicles to meet new CAFE levels 

will improve fuel efficiency and reduce the cost of operating the more efficient vehicles. The 

effectiveness of each technology determines how large an impact it will have towards enabling 

manufacturers to meet the higher CAFE standards, and will thus determine how much additional 

improvement is needed and which additional technologies will be required to achieve full 

compliance. In selecting the likely path that manufacturers will choose to meet CAFE, the 

CAFE model tests the interaction of technology costs and effectiveness to achieve an optimal 

(cost-minimizing) technological solution. Technology effectiveness is thus a primary 

determinant of the overall cost and benefit of improving fuel economy. 

As noted above, forty-one different technologies were examined as possible methods to comply 

with higher CAFE standards. These technologies were summarized in Chapter V earlier in this 

analysis. Chapter V also summarizes the estimated range of effectiveness for these technologies. 

The expected values (mid-range values) were used in the main analysis. For the uncertainty 

analysis, the full range of effectiveness estimates is used. The uncertainties model assumes a 

normal distribution for these values, with each end of the range being three standard deviations 

from the mean (or expected) value. 
X-4

Fuel Prices 

Higher CAFE standards will result in reduced gasoline consumption, which will translate into 

lower vehicle operating costs for consumers. The value of this reduced fuel consumption is a 

direct function of fuel prices. Fuel prices are thus a primary determinant of the overall social 

benefit that will result from improving fuel economy. 

The analysis attempts to measure impacts that occur as much as 40 years in the future and 

estimating gasoline prices this far in advance is an uncertain process. In the main analysis, the 

agency utilized predicted fuel prices from the Energy Information Administration’s (EIA) 

publication Annual Energy Outlook 2008 (AEO) Revised Early Release. The main analysis is 

based on the AEO Reference Case scenario, which represents EIA’s best estimate of future fuel 

prices. For the uncertainty analysis, the Agency examined two other AEO scenarios, the Low 

Oil Price scenario (LOP) and the High Oil Price scenario (HOP). The AEO 2008 Early Release 

did not contain LOP and HOP estimates. The agency therefore estimated these levels by 

adjusting the 2008 Reference case proportionately to these cases in the AEO 2007 report. The 

LOP scenario was chosen to allow for the possibility that the EIA’s Reference Case predictions 

could overestimate the price of gasoline in the future. However, recent escalation in the price of 

gasoline has resulted in prices that have at times exceeded those estimated by EIA for their 

reference case. It is unclear whether this just reflects a temporary spike in price levels or 

whether it is an indication of permanently higher price levels. To reflect the possibility of 

significantly higher prices, the Agency selected the HOP case, which among the AEO 2008 

scenarios comes closest to matching the highest prices seen during the recent gasoline price 

surge, and which gives the highest gasoline price forecasts among all AEO 2008 scenarios 

 

Each of these scenarios was applied as a discrete input (i.e., draws were not made from among 

the three scenarios separately for each future year). Rather, for each draw, one of the three 

scenarios was chosen and applied across the full vehicle life for each model year. The 

probability of selection for each of the three scenarios was modeled using discrete weights of 50 

percent for the Reference Case, and 25 percent for both the LOP and HOP cases. Table X-1 lists 

the AEO gasoline price forecasts under each scenario. These same prices are demonstrated 

graphically (in 2006 economics) in Figure X-2. Note that these prices include Federal, State, and 

local fuel taxes. For the uncertainty analysis, taxes were removed because they are viewed as 

transfer payments (see discussion in Chapter VIII). Estimated retail prices are shown here 

because they are a better reference point for most readers. 

 

 
X-5

Table X-1 

AEO 2008 Gasoline Price Scenarios 

 Low Forecast High 

2011 $2.302 $2.553 $3.056 

2012 $2.151 $2.477 $3.068 

2013 $2.069 $2.405 $3.082 

2014 $2.076 $2.389 $3.189 

2015 $1.986 $2.316 $3.194 

2016 $1.931 $2.255 $3.139 

2017 $1.892 $2.267 $3.162 

2018 $1.940 $2.293 $3.237 

2019 $1.991 $2.362 $3.320 

2020 $2.047 $2.420 $3.430 

2021 $2.027 $2.386 $3.410 

2022 $2.021 $2.406 $3.418 

2023 $2.057 $2.414 $3.467 

2024 $2.039 $2.409 $3.452 

2025 $2.040 $2.425 $3.486 

2026 $2.057 $2.438 $3.577 

2027 $2.031 $2.451 $3.609 

2028 $2.029 $2.474 $3.641 

2029 $2.040 $2.498 $3.712 

2030 $2.052 $2.514 $3.736 

2031 $2.052 $2.514 $3.736 

2032 $2.052 $2.514 $3.736 

2033 $2.052 $2.514 $3.736 

2034 $2.052 $2.514 $3.736 

2035 $2.052 $2.514 $3.736 

2036 $2.052 $2.514 $3.736 

2037 $2.052 $2.514 $3.736 

2038 $2.052 $2.514 $3.736 

2039 $2.052 $2.514 $3.736 

2040 $2.052 $2.514 $3.736 

2041 $2.052 $2.514 $3.736 

2042 $2.052 $2.514 $3.736 

2043 $2.052 $2.514 $3.736 

2044 $2.052 $2.514 $3.736 

2045 $2.052 $2.514 $3.736 

2046 $2.052 $2.514 $3.736 

2047 $2.052 $2.514 $3.736 

 
X-6

Figure X-2 

AEO Gasoline Price Forecasts

$0.000

$0.500

$1.000

$1.500

$2.000

$2.500

$3.000

$3.500

$4.000

2011201420172020202320262029203220352038204120442047

Year

Retail Price

Low

Forecast

 High

 

Oil Consumption Externalities 

Reduced fuel consumption can benefit society by lowering the world market price for oil, 

reducing the threat of petroleum supply disruptions, and reducing the cost of maintaining 

military security in oil producing regions and operating the strategic petroleum reserve. These 

benefits are called “externalities” because they are not reflected directly in the market price of 

fuel. A full description of these externalities is included in Chapter VIII under “Other Economic 

Benefits from Reducing Petroleum Use.” These factors increase the net social benefits from 

reduced fuel consumption. Although they represent a relatively small portion of overall social 

benefits, there is a significant level of uncertainty as to their values. For this reason, they were 

examined in the uncertainty analysis. 

Table X-3 lists the range of values that were examined for oil consumption externalities. The 

expected values were used in the main analysis. Both the value of reducing U.S. demand on the 

world market price for oil and the value of reduced threat of supply disruptions were derived 

from a study by Leiby (2008) (see Chapter VIII). For reasons noted in Chapter VIII, military 

security is not specifically valued in this analysis. A normal distribution was assumed for the 

range of values for oil consumption externalities with the low and high values assumed to be two 

standard deviations from the mean, based on the Leiby estimates. 

Table X-3 

Uncertainty Ranges for Oil Consumption Externalities ($/gallon) 

 

Low Expected High 

For reducing U.S. demand on world 

market price 

$0.028 $0.182 $0.336 

For reducing the threat of supply 

disruptions 

$0.035 $0.113 $0.191 
X-7

The Rebound Effect 

By reducing the amount of gasoline used and, thus, the cost of operating a vehicle, higher CAFE 

standards are expected to result in a slight increase in annual miles driven per vehicle. This 

“rebound effect” impacts net societal benefits because the increase in miles driven offsets a 

portion of the gasoline savings that results from more fuel-efficient vehicles. Although 

consumers derive some value from this extra driving, it also leads to increases in crash, 

congestion, noise, and pollution costs associated with driving. Most recent estimates of the 

magnitude of the rebound effect for light duty vehicles fall in the range of 10-20 percent (i.e., 

increasing vehicle use will offset 10-20 percent of the fuel savings resulting from an 

improvement in fuel economy). A more complete discussion of the rebound effect is included in 

Chapter VIII. The agency employed a rebound effect of 15 percent in the main analysis. For 

the uncertainty analysis, a range of 10 to 20 percent is used and employed in a skewed Beta 

distribution which produced a mean of approximately 14 percent. The skewed distribution 

reflects the agency’s belief that the more credible studies that differ from the 15 percent value 

chosen for the main analysis fall below this value and differ by more substantial margins than the 

upper range of credible values. Table X-3 Summarizes the economic parameters used in the 

uncertainty analysis. 

Table X-3 

Monte-Carlo Specific Parameters 

 

Alternative Discount Rates (%) 0.03 

Rebound Randomization Parameters 

Rebound Alpha Shape 6.0 

Rebound Beta Shape 2.7 

Rebound Scale -0.20 

Rebound Base -0.05 

Monopsony Randomization Parameters 

Monopsony Mean $0.182 

Monopsony Standard Deviation $0.077 

Price Shock Randomization Parameters 

Price Shock Mean $0.113 

Price Shock Standard Deviation $0.039 

Military Security Randomization Parameters 

Military Security Mean $0.000 

Military Security Standard Deviation $0.000 

Total Economic Costs of Petroleum Randomization Parameters 

(Specified in $/gallon) 

Total Economic Costs Alpha Shape 4 

Total Economic Costs Beta Shape 2.4118 

Total Economic Costs Scale 0.46 

Total Economic Costs Base 0.05 

Carbon Dioxide Randomization Parameters 

CO-2 Mean $7.00 

CO-2 Standard Deviation $3.25 

Default Cost and FC Variations 

Cost Variation % 0.37 

FC Variation % 0.31 
X-8

Modeling Results – Trial Draws 

Because of the complexity of the CAFE model, the computer time required to perform the 

uncertainty analysis was significant. The uncertainty analysis conducted a total of 40,000 trials 

(20,000 for each discount rate) Figures X- 3 through X-14 graphically illustrate the draw results 

for a sample of the 85 variables (41 technology effectiveness rates, 41 technology costs, the fuel 

price scenario, oil import externalities, the rebound effect, and CO2.) that were examined. 

Tables X-3 through X-7 list the draw results for each economic input, technology cost, and 

technology effectiveness. 

 

Figure X-3 

Monte Carlo Draw Profile, Passenger Car Costs 

Turbocharging and Downsizing

0

200

400

600

800

1000

1200

1400

1600

1800

207.600 283.600 359.600 435.600 511.600

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %
X-9

Figure X-4 

Monte Carlo Draw Profile, Passenger Car Effectiveness 

Turbocharging and Downsizing

0

200

400

600

800

1000

1200

1400

1600

1800

0.014 0.019 0.023 0.027 0.031

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-5 

Monte Carlo Draw Profile, Passenger Cars, Costs 

Diesel following HCCI

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1,017.20 1,439.20 1,861.20 2,283.20 2,705.20

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %
X-10

Figure X-6 

Monte Carlo Draw Profile, Passenger Cars, Effectiveness 

Diesel following HCCI

0

500

1000

1500

2000

2500

0.05 0.06 0.08 0.10 0.11

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-7 

Monte Carlo Draw Profile, Passenger Cars, Costs 

Automatic Manual Transmission

0

200

400

600

800

1000

1200

1400

1600

1800

67.800 95.800 123.800 151.800 179.800

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %
X-11

Figure X-8 

Monte Carlo Draw Profile, Passenger Cars, Effectiveness

Automatic Manual Transmission

0

200

400

600

800

1000

1200

1400

1600

1800

0.041 0.049 0.057 0.065 0.073

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-9 

Monte Carlo Draw Profile

Pretax Fuel Price Path 

0%

10%

20%

30%

40%

50%

60%

Low Mid High

Relative Frequency

 
X-12

Figure X-10 

Monte Carlo Draw Profile

CO2 Costs

0

200

400

600

800

1000

1200

1400

0.400 3.600 6.800 10.000 13.200 16.400 19.600

Number of trials

0%

25%

50%

75%

100%

125%

Cumulative % Frequency

Figure X-11

Monte Carlo Draw Profile

Monopsony Cost

0

200

400

600

800

1000

1200

1400

1600

0.000 0.082 0.163 0.245 0.327 0.408 0.490

Number of trials

0%

25%

50%

75%

100%

125%

Cumulative % Frequency
X-13

Figure X-12 

Monte Carlo Draw Profile 

Rebound Effect

0

200

400

600

800

1000

1200

1400

-0.20 -0.15 -0.10 -0.05

Number of trials

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-13 

Monte Carlo Draw Profile

Price Shock Cost

0

200

400

600

800

1000

1200

1400

1600

0.005 0.049 0.092 0.135 0.178 0.221 0.265

Number of trials

0%

25%

50%

75%

100%

125%

Cumulative % Frequency
X-14

Figure X-14 

Monte Carlo Draw Profile

Total Economic Costs

0

200

400

600

800

1000

1200

1400

0.011 0.099 0.187 0.275 0.363 0.451 0.539

Number of trials

0%

25%

50%

75%

100%

125%

Cumulative % Frequency

 Table X-3 

 Monte Carlo Draw Results, Economic Inputs 

Economic Inputs Minimum Maximum Mean StdDev 

 

Rebound Effect -0.200 -0.050 -0.139 0.031

Monopsony Cost 2.08E-05 0.4758454 0.184348 0.075127

Price Cost Shock 0.000587 0.2694044 0.112852 0.038933

Total Economic Costs 0.051902 0.508969 0.328306 0.087728

CO2 Costs 0.003939 19.552248 7.150228 3.110129
X-15

 Table X-4 

 Monte Carlo Draw Results, Passenger Car Technology Costs 

Passenger Car Technology Costs Minimum Maximum Mean StdDev 

Low Friction Lubricants $1.49 $4.74 $3.00 $0.37

Engine Friction Reduction $0.33 $119.10 $52.78 $17.42

Variable Valve Timing (ICP) $46.16 $142.36 $89.60 $11.00

Variable Valve Timing (CCP) $0.00 $0.00 $0.00 $0.00

Variable Valve Timing (DCP) $29.90 $93.84 $60.68 $7.50

Cylinder Deactivation $53.49 $165.05 $103.36 $12.82

Variable Valve Lift & Timing (CVVL) $180.04 $553.92 $361.94 $44.52

Variable Valve Lift & Timing (DVVL) $103.16 $327.22 $208.04 $25.65

Cylinder Deactivation on OHV $54.85 $152.41 $103.52 $12.78

Variable Valve Timing (CCP) on OHV $29.20 $94.35 $59.33 $7.33

Multivalve Overhead Cam with CVVL $469.56 $1,444.80 $936.29 $114.36

Variable Valve Lift & Timing (DVVL) on OHV $103.30 $307.42 $208.46 $25.57

Camless Valve Actuation $0.00 $0.00 $0.00 $0.00

Stoichiometric GDI $123.72 $536.56 $318.20 $48.03

Diesel following GDI-S (SIDI) $1,235.43 $3,339.62 $2,219.62 $275.52

Lean Burn GDI $0.00 $0.00 $0.00 $0.00

Turbocharging and Downsizing $204.72 $577.86 $399.36 $49.36

Diesel following Turbo D/S $946.96 $2,877.83 $1,822.07 $224.84

HCCI $145.97 $440.72 $289.76 $35.85

Diesel following HCCI $991.05 $3,075.29 $1,932.76 $238.19

5 Speed Automatic Transmission $59.29 $180.41 $121.75 $15.09

Aggressive Shift Logic $18.76 $55.53 $38.05 $4.68

Early Torque Converter Lockup $15.13 $47.27 $30.01 $3.68

6 Speed Automatic Transmission $0.00 $0.00 $0.00 $0.00

Continuously Variable Transmission $65.89 $187.47 $120.00 $14.91

6 Speed Manual $54.50 $168.33 $106.43 $13.08

Improved Accessories $116.76 $174.09 $145.25 $6.90

Electronic Power Steering $103.77 $214.40 $157.73 $13.06

42-Volt Electrical System $184.50 $267.97 $226.75 $10.75

Low Rolling Resistance Tires $3.25 $8.69 $6.00 $0.74

Low Drag Brakes $0.00 $0.00 $0.00 $0.00

Secondary Axle Disconnect - Unibody $633.60 $721.41 $675.69 $11.88

Secondary Axle Disconnect - Ladder Frame $0.00 $0.00 $0.00 $0.00

Aero Drag Reduction $0.19 $84.64 $37.59 $12.40

Material Substitution (1%) $0.00 $0.00 $0.00 $0.00

Material Substitution (2%) $0.00 $0.00 $0.00 $0.00

Material Substitution (5%) $0.00 $0.00 $0.00 $0.00

ISG with Idle-Off $299.07 $858.05 $581.96 $71.76

IMA/ISAD/BSG Hybrid (includes engine 

downsizing $967.35 $3,068.39 $1,958.43 $242.67

2-Mode Hybrid $391.09 $1,163.87 $764.67 $94.39

Power Split Hybrid $309.05 $960.34 $627.41 $76.93
X-16

 Table X-5 

 Monte Carlo Draw Results, Passenger Car Fuel Economy Improvement Rates 

Passenger Car Fuel Economy Improvement 

Rates Minimum Maximum Mean StdDev 

Low Friction Lubricants 0.002908 0.0073035 0.004997 0.000518

Engine Friction Reduction 0.004595 0.0329195 0.01996 0.003341

Variable Valve Timing (ICP) 0.009356 0.0206904 0.014895 0.001545

Variable Valve Timing (CCP) 0.011859 0.0281932 0.020186 0.002083

Variable Valve Timing (DCP) 0.011895 0.0280668 0.02018 0.002085

Cylinder Deactivation 0.013563 0.0348619 0.022915 0.00237

Variable Valve Lift & Timing (CVVL) 0.023194 0.0522346 0.037476 0.003869

Variable Valve Lift & Timing (DVVL) 0.013216 0.0318864 0.022365 0.002324

Cylinder Deactivation on OHV 0.018306 0.044046 0.030546 0.003144

Variable Valve Timing (CCP) on OHV 0.017041 0.0407676 0.027473 0.00283

Multivalve Overhead Cam with CVVL 0.017591 0.0444581 0.030094 0.003111

Variable Valve Lift & Timing (DVVL) on OHV 0.008878 0.0223505 0.014976 0.001546

Camless Valve Actuation 0 0 0 0

Stoichiometric GDI 0.007243 0.0217997 0.014994 0.001682

Diesel following GDI-S (SIDI) 0.094756 0.2441063 0.160479 0.01659

Lean Burn GDI 0.023047 0.0549808 0.037155 0.003851

Turbocharging and Downsizing 0.014385 0.0345359 0.024998 0.002575

Diesel following Turbo D/S 0.078206 0.1893723 0.135461 0.013972

HCCI 0.044389 0.1117523 0.075102 0.007783

Diesel following HCCI 0.049223 0.1261183 0.085368 0.008877

5 Speed Automatic Transmission 0.015092 0.0344635 0.024962 0.002575

Aggressive Shift Logic 0.007926 0.0215958 0.015003 0.001683

Early Torque Converter Lockup 0.002939 0.0074048 0.004999 0.000518

6 Speed Automatic Transmission 0.000918 0.0281055 0.01499 0.003332

Continuously Variable Transmission 0.020615 0.0505527 0.034988 0.003622

6 Speed Manual 0.002992 0.0069901 0.005 0.000518

Improved Accessories 0.007504 0.0212326 0.015009 0.001664

Electronic Power Steering 0.015584 0.0168713 0.016271 0.000147

42-Volt Electrical System 0.008567 0.0217223 0.014992 0.001662

Low Rolling Resistance Tires 0.008928 0.0218487 0.014998 0.001664

Low Drag Brakes 0 0 0 0

Secondary Axle Disconnect - Unibody 0.005908 0.0144799 0.009997 0.001032

Secondary Axle Disconnect - Ladder Frame 0 0 0 0

Aero Drag Reduction 0.017873 0.041923 0.029955 0.003111

Material Substitution (1%) 0.005713 0.0071391 0.006498 0.000168

Material Substitution (2%) 0.00586 0.0071669 0.0065 0.000167

Material Substitution (5%) 0.016592 0.0214113 0.019248 0.000582

ISG with Idle-Off 0.044364 0.1094447 0.075005 0.0078

IMA/ISAD/BSG Hybrid (includes engine 

downsizing) 0.03486 0.083258 0.059502 0.006136

2-Mode Hybrid 0.010524 0.0267755 0.017813 0.001832

Power Split Hybrid 0.03312 0.0822965 0.057607 0.00598
X-17

 Table X-6 

 Monte Carlo Draw Results, Light Truck Technology Costs 

Light Truck Technology Costs Minimum Maximum Mean StdDev 

Low Friction Lubricants $1.49 $4.74 $3.00 $0.37

Engine Friction Reduction $0.42 $155.39 $68.86 $22.73

Variable Valve Timing (ICP) $61.18 $188.69 $118.76 $14.58

Variable Valve Timing (CCP) $0.00 $0.00 $0.00 $0.00

Variable Valve Timing (DCP) $44.25 $138.87 $89.81 $11.10

Cylinder Deactivation $108.70 $335.40 $210.04 $26.04

Variable Valve Lift & Timing (CVVL) $237.53 $730.81 $477.52 $58.74

Variable Valve Lift & Timing (DVVL) $132.02 $418.79 $266.26 $32.82

Cylinder Deactivation on OHV $111.47 $309.70 $210.37 $25.96

Variable Valve Timing (CCP) on OHV $29.20 $94.35 $59.33 $7.33

Multivalve Overhead Cam with CVVL $648.92 $1,996.67 $1,293.93 $158.04

Variable Valve Lift & Timing (DVVL) on OHV $132.21 $393.45 $266.80 $32.73

Camless Valve Actuation $0.00 $0.00 $0.00 $0.00

Stoichiometric GDI $142.88 $619.65 $367.48 $55.47

Diesel following GDI-S (SIDI) $1,470.51 $3,975.08 $2,641.97 $327.94

Lean Burn GDI $0.00 $0.00 $0.00 $0.00

Turbocharging and Downsizing $157.93 $445.79 $308.09 $38.08

Diesel following Turbo D/S $1,214.16 $3,689.84 $2,336.19 $288.28

HCCI $209.73 $633.21 $416.31 $51.51

Diesel following HCCI $1,143.01 $3,546.83 $2,229.12 $274.71

5 Speed Automatic Transmission $59.29 $180.41 $121.75 $15.09

Aggressive Shift Logic $18.76 $55.53 $38.05 $4.68

Early Torque Converter Lockup $15.13 $47.27 $30.01 $3.68

6 Speed Automatic Transmission $0.00 $0.00 $0.00 $0.00

Continuously Variable Transmission $8.78 $24.99 $16.00 $1.99

6 Speed Manual $54.50 $168.33 $106.43 $13.08

Improved Accessories $116.76 $174.09 $145.25 $6.90

Electronic Power Steering $103.77 $214.40 $157.73 $13.06

42-Volt Electrical System $184.50 $267.97 $226.75 $10.75

Low Rolling Resistance Tires $2.36 $6.31 $4.36 $0.54

Low Drag Brakes $38.97 $122.58 $77.27 $9.63

Secondary Axle Disconnect - Unibody $580.10 $660.49 $618.63 $10.87

Secondary Axle Disconnect - Ladder Frame $55.77 $159.17 $100.75 $12.41

Aero Drag Reduction $0.19 $84.64 $37.59 $12.40

Material Substitution (1%) $0.26 $0.73 $0.50 $0.06

Material Substitution (2%) $0.37 $0.98 $0.67 $0.08

Material Substitution (5%) $0.46 $1.23 $0.83 $0.10

ISG with Idle-Off $308.54 $885.22 $600.39 $74.03

IMA/ISAD/BSG Hybrid (includes engine 

downsizing $0.00 $0.00 $0.00 $0.00

2-Mode Hybrid $2,121.66 $6,314.06 $4,148.37 $512.05

Power Split Hybrid $0.00 $0.00 $0.00 $0.00
X-18

 Table X-7 

 Monte Carlo Draw Results, Light Truck Fuel Economy Improvement Rates

Light Truck Technology Improvement Rates Minimum Maximum Mean StdDev 

Low Friction Lubricants 0.002908 0.007303 0.004997 0.000518

Engine Friction Reduction 0.004595 0.03292 0.01996 0.003341

Variable Valve Timing (ICP) 0.007989 0.017667 0.012718 0.001319

Variable Valve Timing (CCP) 0.008747 0.020794 0.014888 0.001536

Variable Valve Timing (DCP) 0.007505 0.01771 0.012733 0.001315

Cylinder Deactivation 0.02665 0.068502 0.045026 0.004656

Variable Valve Lift & Timing (CVVL) 0.012312 0.027728 0.019894 0.002054

Variable Valve Lift & Timing (DVVL) 0.00584 0.014089 0.009882 0.001027

Cylinder Deactivation on OHV 0.03597 0.086549 0.060021 0.006178

Variable Valve Timing (CCP) on OHV 0.00783 0.018731 0.012623 0.001301

Multivalve Overhead Cam with CVVL 0.011624 0.029378 0.019886 0.002056

Variable Valve Lift & Timing (DVVL) on OHV 0.005849 0.014726 0.009867 0.001019

Camless Valve Actuation 0 0 0 0

Stoichiometric GDI 0.007243 0.0218 0.014994 0.001682

Diesel following GDI-S (SIDI) 0.106364 0.274009 0.180138 0.018622

Lean Burn GDI 0 0 0 0

Turbocharging and Downsizing 0.014385 0.034536 0.024998 0.002575

Diesel following Turbo D/S 0.089555 0.216855 0.155119 0.015999

HCCI 0.044389 0.111752 0.075102 0.007783

Diesel following HCCI 0.06055 0.155142 0.105014 0.01092

5 Speed Automatic Transmission 0.015092 0.034464 0.024962 0.002575

Aggressive Shift Logic 0.007926 0.021596 0.015003 0.001683

Early Torque Converter Lockup 0.002939 0.007405 0.004999 0.000518

6 Speed Automatic Transmission 0.000918 0.028105 0.01499 0.003332

Continuously Variable Transmission 0.010549 0.025869 0.017904 0.001853

6 Speed Manual 0.002992 0.00699 0.005 0.000518

Improved Accessories 0.007504 0.021233 0.015009 0.001664

Electronic Power Steering 0.019155 0.020736 0.019999 0.000181

42-Volt Electrical System 0.008567 0.021722 0.014992 0.001662

Low Rolling Resistance Tires 0.006489 0.015879 0.010901 0.00121

Low Drag Brakes 0.002886 0.00734 0.004883 0.000504

Secondary Axle Disconnect - Unibody 0.004294 0.010524 0.007266 0.00075

Secondary Axle Disconnect - Ladder Frame 0.004331 0.010856 0.007326 0.000759

Aero Drag Reduction 0.014964 0.0351 0.02508 0.002605

Material Substitution (1%) 0.005713 0.007139 0.006498 0.000168

Material Substitution (2%) 0.00586 0.007167 0.0065 0.000167

Material Substitution (5%) 0.016592 0.021411 0.019248 0.000582

ISG with Idle-Off 0.044364 0.109445 0.075005 0.0078

IMA/ISAD/BSG Hybrid (includes engine 

downsizing) 0 0 0 0

2-Mode Hybrid 0.035708 0.090851 0.06044 0.006215

Power Split Hybrid 0.027148 0.067457 0.047219 0.004901
X-19

Modeling Results – Output 

Tables X-8 and X-9 summarize the modeling results for fuel saved, total costs, societal benefits, 

and net benefits for passenger cars and trucks respectively under a 7% discount rate. They also 

indicate the probability that net benefits exceed zero. Tables X-10 and X-11 summarize these 

same results under a 3% discount rate. These results are also illustrated in Figures X-15 

through X-18 for passenger cars under Optimized CAFE at 7 percent for MY 2015. Although 

not shown here, the general shape of the resulting output distributions are similar for the light 

trucks, the 3 percent discount rate, and for other model years as well. The humped shape that 

occurs for both social benefits and net benefits reflects the three different gasoline price 

scenarios. About half of all draws were selected from the AEO Reference Case, while about one 

quarter were drawn from the Low Oil Price scenario and one quarter were drawn from the High 

Oil Price scenario. This produces three separate humps which reflect the increasing impact on 

benefits from the three progressively higher oil price scenarios. The Low Oil scenario is close 

enough to the Forecast scenario that the 2 humps visually begin to merge. However, the 

difference between the High Oil Price scenario and the Forecast is typically more than double the 

difference between the Forecast and the Low Oil price scenario, which results in a separate 

distribution further up the x axis. The following discussions summarize the range of results 

presented in these tables for the combined passenger car and light truck across both the 7 percent 

(typically the lower range) and 3 percent (typically upper range) discount rates212. 

Fuel Savings: The analysis indicates that MY 2011 vehicles (both passenger cars and light 

trucks) will experience between 3,370 million and 4,735 million gallons of fuel savings over 

their useful lifespan. MY 2012 vehicles will experience between 7,476 million and 9,639 

million gallons of fuel savings over their useful lifespan. MY 2013 vehicles will experience 

between 10,863 million and 13,763 million gallons of fuel savings over their useful lifespan. 

MY 2014 vehicles will experience between 12,568 and 15,664 million gallons of fuel savings 

over their useful lifespan. MY 2015 vehicles will experience between 14,188 and 17,659 million 

gallons of fuel savings over their useful lifespan. Over the combined lifespan of the five model 

years, between 48.5 billion and 61.4 billion gallons of fuel will be saved. 

Total Costs: The analysis indicates that owners of MY 2011 passenger cars and light trucks will 

pay between $2,447 million and $5,256 million in higher vehicle prices to purchase vehicles with 

improved fuel efficiency. MY 2012 owners will pay between $5,817 million and $10,427 

million more. MY 2013 owners will pay between $7,942 million and $15,288 million more. 

MY 2014 owners will pay between $9,338 million and $17,189 million more. MY 2015 owners 

will pay between $10,940 million and $19,842 million more. Owners of all five model years 

vehicles combined will pay between $36.5 billion and $67.9 billion in higher vehicle prices to 

purchase vehicles with improved fuel efficiency. 

 

212 In a few cases the upper range results were obtained from the 7% rate and the lower range results were obtained 

from the 3% rate. While this may seem counterintuitive, it results from the random selection process that is inherent 

in the Monte Carlo technique. 
X-20

Societal Benefits: The analysis indicates that changes to MY 2011 passenger cars and light 

trucks to meet the proposed CAFE standards will produce overall societal benefits valued 

between $4,375 million and $13,041 million. MY 2012 vehicles will produce benefits valued 

between $9,363 million and $28,214 million. MY 2013 vehicles will produce benefits valued 

between $13,370 million and $41,027 million. MY 2014 vehicles will produce benefits valued 

between $15,586 million and $47,087 million. MY 2015 vehicles will produce benefits valued 

between $17,486 million and $53,708 million. Over the combined lifespan of the five model 

years, societal benefits valued between $60.1 billion and $183.1 billion will be produced. 

Net Benefits: The uncertainty analysis indicates that the net impact of the higher CAFE 

requirements for MY 2011 passenger cars and light trucks will be a net benefit of between $937 

million and $9,678 million. There is at least a 99.3 percent certainty that changes made to MY 

2011 vehicles to achieve the higher CAFE standards will produce a net benefit. The net impact 

of the higher CAFE requirements for MY 2012 will be a net benefit of between $283 million and 

a net benefit of $21,139 million. There is at least a 99.6 percent certainty that changes made to 

MY 2012 vehicles to achieve the CAFE standards will produce a net benefit. The net impact of 

the higher CAFE requirements for MY 2013 will be a net benefit of between $494 million and a 

net benefit of $31,311 million. There is at least a 99.6 percent certainty that changes made to 

MY 2013 vehicles to achieve the higher CAFE standards will produce a net benefit. The net 

impact of the higher CAFE requirements for MY 2014 will be a net benefit of between $711 

million and $35,746 million. There is 100 percent certainty that changes made to MY 2014 

vehicles to achieve the CAFE standards will produce a net benefit. The net impact of the higher 

CAFE requirements for MY 2015 will be a net benefit of between $654 million and $40,703 

million. There is 100 percent certainty that changes made to MY 2015 vehicles to achieve the 

CAFE standards will produce a net benefit. Over all five model years, the higher CAFE 

standards will produce net benefits ranging from $3.1 billion to $138.6 billion. There is at least a 

99.3 percent certainty that higher CAFE standards will produce a net societal benefit in each of 

the model years covered by this final rule. In most years, this probability is 100%. 
X-21

Table X-8 

Uncertainty Analysis Results, Passenger Cars 

(7% Discount Rate) 

MY 2011 Mean Low High 

Fuel Saved (mill. gall.) 1487 1285 1813 

Total Cost ($mill.) 1760 1291 2302 

Societal Benefits ($mill.) 2605 1723 4201 

Net Benefits ($mill.) 845 435 2574 

% Certainty Net Ben. > 0 99.3% 

 

MY 2012 

Fuel Saved (mill. gall.) 2870 2618 3403 

Total Cost ($mill.) 2271 1676 3237 

Societal Benefits ($mill.) 5023 3296 8127 

Net Benefits ($mill.) 2753 404 6009 

% Certainty Net Ben. > 0 100% 

 

MY 2013 

Fuel Saved (mill. gall.) 3585 3237 4283 

Total Cost ($mill.) 2769 2021 3970 

Societal Benefits ($mill.) 6280 4071 10388 

Net Benefits ($mill.) 3511 493 7666 

% Certainty Net Ben. > 0 100% 

 

MY 2014 

Fuel Saved (mill. gall.) 4613 4200 5372 

Total Cost ($mill.) 3707 2793 5109 

Societal Benefits ($mill.) 8113 5262 12996 

Net Benefits ($mill.) 4407 589 9669 

% Certainty Net Ben. > 0 100% 

 

MY 2015 

Fuel Saved (mill. gall.) 5513 5025 6389 

Total Cost ($mill.) 4713 3773 6339 

Societal Benefits ($mill.) 9703 6296 15668 

Net Benefits ($mill.) 4989 445 11413 

% Certainty Net Ben. > 0 100% 
X-22

Table X-9 

Uncertainty Analysis Results, Light Trucks 

(7% Discount Rate) 

MY 2011 Mean Low High 

Fuel Saved (mill. gall.) 2312 2085 2922 

Total Cost ($mill.) 1696 1156 2954 

Societal Benefits ($mill.) 3968 2652 6131 

Net Benefits ($mill.) 2272 502 4491 

% Certainty Net Ben. > 0 100.0 

 

MY 2012 

Fuel Saved (mill. gall.) 5373 4858 6236 

Total Cost ($mill.) 5213 4141 7190 

Societal Benefits ($mill.) 9128 6067 14300 

Net Benefits ($mill.) 3915 -121 9273 

% Certainty Net Ben. > 0 99.6% 

 

MY 2013 

Fuel Saved (mill. gall.) 8270 7626 9453 

Total Cost ($mill.) 7501 5921 11318 

Societal Benefits ($mill.) 14053 9299 21967 

Net Benefits ($mill.) 6552 -29 15031 

% Certainty Net Ben. > 0 99.6 

 

MY 2014 

Fuel Saved (mill. gall.) 9071 8381 10258 

Total Cost ($mill.) 8216 6545 12080 

Societal Benefits ($mill.) 15489 10324 24311 

Net Benefits ($mill.) 7273 122 16549 

% Certainty Net Ben. > 0 100.0% 

 

MY 2015 

Fuel Saved (mill. gall.) 9942 9163 11270 

Total Cost ($mill.) 8996 7167 13435 

Societal Benefits ($mill.) 17013 11190 26862 

Net Benefits ($mill.) 8018 209 18321 

% Certainty Net Ben. > 0 100% 
X-23

Table X-10 

Uncertainty Analysis Results, Passenger Cars 

(3% Discount Rate) 

MY 2011 Mean Low High 

Fuel Saved (mill. gall.) 1503 1285 1798 

Total Cost ($mill.) 1782 1309 2295 

Societal Benefits ($mill.) 3235 2142 5087 

Net Benefits ($mill.) 1454 -29 3544 

% Certainty Net Ben. > 0 100% 

 

MY 2012 

Fuel Saved (mill. gall.) 2889 2621 3392 

Total Cost ($mill.) 2299 1695 3286 

Societal Benefits ($mill.) 6215 4050 10036 

Net Benefits ($mill.) 3916 1180 7953 

% Certainty Net Ben. > 0 100% 

 

MY 2013 

Fuel Saved (mill. gall.) 3611 3245 4284 

Total Cost ($mill.) 2807 2086 3990 

Societal Benefits ($mill.) 7789 5002 12868 

Net Benefits ($mill.) 4982 1468 10164 

% Certainty Net Ben. > 0 100% 

 

MY 2014 

Fuel Saved (mill. gall.) 4639 4220 5374 

Total Cost ($mill.) 3754 2877 5050 

Societal Benefits ($mill.) 10053 6475 16285 

Net Benefits ($mill.) 6299 1847 12783 

% Certainty Net Ben. > 0 100% 

 

MY 2015 

Fuel Saved (mill. gall.) 5538 5047 6389 

Total Cost ($mill.) 4764 3730 6298 

Societal Benefits ($mill.) 12025 7770 19419 

Net Benefits ($mill.) 7262 1956 15167 

% Certainty Net Ben. > 0 100% 

Table X-11 
X-24

Uncertainty Analysis Results, Light Trucks 

(3% Discount Rate) 

MY 2011 Mean Low High 

Fuel Saved (mill. gall.) 2324 2090 2836 

Total Cost ($mill.) 1721 1190 2922 

Societal Benefits ($mill.) 5031 3359 7954 

Net Benefits ($mill.) 3311 1324 6134 

% Certainty Net Ben. > 0 100% 

 

MY 2012 

Fuel Saved (mill. gall.) 5371 4855 6234 

Total Cost ($mill.) 5212 4200 7046 

Societal Benefits ($mill.) 11522 7622 18178 

Net Benefits ($mill.) 6310 1853 13186 

% Certainty Net Ben. > 0 100% 

 

MY 2013 

Fuel Saved (mill. gall.) 8278 7640 9479 

Total Cost ($mill.) 7517 6049 11122 

Societal Benefits ($mill.) 17791 11729 28159 

Net Benefits ($mill.) 10274 2736 21147 

% Certainty Net Ben. > 0 100% 

 

MY 2014 

Fuel Saved (mill. gall.) 9074 8348 1029 

Total Cost ($mill.) 8227 6567 11945 

Societal Benefits ($mill.) 19618 12966 30802 

Net Benefits ($mill.) 11391 3169 22963 

% Certainty Net Ben. > 0 100% 

 

MY 2015 

Fuel Saved (mill. gall.) 9942 9175 11264 

Total Cost ($mill.) 9008 7297 13544 

Societal Benefits ($mill.) 21567 14121 34289 

Net Benefits ($mill.) 12559 3551 25536 

% Certainty Net Ben. > 0 100% 
X-25

Figure X-13 

 Model Output Profile 

Cars: Fuel Savings for "Optimized Reformed 

Standards" (2015) at 7% Discount Rate

0

200

400

600

800

1000

1200

1400

1600

5,052,314

5,188,708

5,325,103

5,461,497

5,597,892

5,734,286

5,870,681

6,007,075

6,143,470

6,279,864

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-14 

Model Output Profile 

Cars: Societal Benefits for "Optimized Reformed 

Standards" (2015) at 7% Discount Rate

0

200

400

600

800

1000

1200

1400

1600

1800

2000

6,483 7,420 8,358 9,295 10,233 11,17012,108 13,04513,983 14,920

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %
X-26

Figure X-15 

Model Output Profile 

Cars: Total Cost for "Optimized Reformed Standards" 

(2015) at 7% Discount Rate

0

200

400

600

800

1000

1200

1400

1600

1800

2000

3,821 4,078 4,335 4,592 4,849 5,106 5,363 5,620 5,877 6,134

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %

Figure X-16 

Model Output Profile 

Cars: Net Benefits for "Optimized Reformed 

Standards" (2015) at 7% Discount Rate

0

200

400

600

800

1000

1200

1400

1600

1800

2000

660 1,757 2,855 3,952 5,050 6,147 7,245 8,342 9,440 10,537

0%

20%

40%

60%

80%

100%

120%

Frequency Cumulative %
 XI-1 

XI. REGULATORY FLEXIBILITY ACT AND UNFUNDED MANDATES REFORM 

ACT ANALYSIS 

A. REGULATORY FLEXIBILITY ACT

The Regulatory Flexibility Act of 1980 (5 U.S.C §601 et seq.) requires agencies to evaluate the 

potential effects of their proposed and final rules on small business, small organizations and 

small Government jurisdictions. 

5 U.S.C §603 requires agencies to prepare and make available for public comments initial and 

final regulatory flexibility analysis (RFA) describing the impact of proposed and final rules on 

small entities. Section 603(b) of the Act specifies the content of a RFA. Each RFA must 

contain: 

1. A description of the reasons why action by the agency is being considered; 

2. A succinct statement of the objectives of, and legal basis for a final rule; 

3. A description of and, where feasible, an estimate of the number of small entities to which 

the final rule will apply; 

4. A description of the projected reporting, recording keeping and other compliance 

requirements of a final rule including an estimate of the classes of small entities which 

will be subject to the requirement and the type of professional skills necessary for 

preparation of the report or record; 

5. An identification, to the extent practicable, of all relevant Federal rules which may 

duplicate, overlap or conflict with the final rule; 

6. Each final regulatory flexibility analysis shall also contain a description of any significant 

alternatives to the final rule which accomplish the stated objectives of applicable statutes 

and which minimize any significant economic impact of the final rule on small entities. 

1. Description of the reason why action by the agency is being considered

NHTSA is proposing this action to improve vehicle fuel economy. 

2. Objectives of, and legal basis for, the final rule

The Energy Policy and Conservation Act requires the agency to set light truck fuel economy 

standards every year and allows the agency to update passenger car fuel economy standards. The 

Energy Independence and Security Act (EISA) mandates the setting of separate standards for 

passenger cars and for light trucks at levels sufficient to ensure that the average fuel economy of 

the combined fleet of all passenger cars and light trucks sold by all manufacturers in the U.S. in 

model year 2020 equals or exceeds 35 miles per gallon. 

 

3. Description and estimate of the number of small entities to which the final rule will apply

The proposal will affect motor vehicle manufacturers. There are no light truck manufacturers 

that are small businesses. However, there are four domestically owned small passenger car 

manufacturers. 

 

Business entities are defined as small business using the North American Industry Classification 

System (NAICS) code, for the purpose of receiving Small Business Administration assistance. 
 XI-2 

One of the criteria for determining size, as stated in 13 CFR 121.201, is the number of employees 

in the firm. For establishments primarily engaged in manufacturing or assembling automobiles, 

light and heavy duty trucks, buses, motor homes, or motor vehicle body manufacturing, the firm 

must have less than 1,000 employees to be classified as a small business. 

We believe that the rulemaking would not have a significant economic impact on the small 

vehicle manufacturers because under Part 525, passenger car manufacturer making less than 

10,000 vehicles per year can petition NHTSA to have alternative standards set for those 

manufacturers. These manufacturers currently don’t meet the 27.5 mpg standard and must 

already petition the agency for relief. If the standard is raised, it has no meaningful impact on 

these manufacturers, they still must go through the same process and petition for relief. 

Currently, there are four small passenger car motor vehicle manufacturers in the United States. 

Table X1-1 provides information about the 4 small domestic manufacturers in MY 2004. All are 

small manufacturers, having much less than 1,000 employees. 

Table XI-1 

Small Vehicle Manufacturers 

Manufacturer Employees Estimated Sales Sale Price Range Est. Revenues* 

Avanti 22 13 $25,000 to $63,000 $572,000 

Panoz 50 150 $90,000 to $125,000 $16,125,000 

Saleen 150 1,000 $39,000 to $59,000 $49,000,000 

Shelby 44 60 $42,000 to $135,000 $5,310,000 

* Assuming an average sales price from the sales price range. 

The agency has not analyzed the impact of the proposal on these small manufacturers. However, 

assuming they would petition the agency, rather than meet the proposal, the cost is not expected 

to be substantial. 

4. A description of the projected reporting, record keeping and other compliance requirements of 

a final rule including an estimate of the classes of small entities which will be subject to the 

requirement and the type of professional skills necessary for preparation of the report or record. 

This proposal includes no new requirements for reporting, record keeping of other compliance 

requirements. 

5. An identification, to the extent practicable, of all relevant Federal rules which may duplicate, 

overlap, or conflict with the final rule 

We know of no Federal rules which duplicate, overlap, or conflict with the final rule. 

6. A description of any significant alternatives to the final rule which accomplish the stated 

objectives of applicable statutes and which minimize any significant economic impact of the 

final rule on small entities.

There are no other alternatives that can achieve the stated objectives without installing fuel 

economy technologies into the vehicle. 
 XI-3 

B. Unfunded Mandates Reform Act 

The Unfunded Mandates Reform Act of 1995 (Public Law 104-4) requires agencies to prepare a 

written assessment of the costs, benefits, and other effects of proposed or final rules that include 

a Federal mandate likely to result in the expenditures by States, local or tribal governments, in 

the aggregate, or by the private sector, of more than $100 million annually (adjusted annually for 

inflation with base year of 1995). Adjusting this amount by the implicit gross domestic product 

price deflator for 2006 results in $126 million (116.043/92.106 = 1.26). The assessment may be 

included in conjunction with other assessments, as it is here. 

C. Market Failure or Other Specific Problem 

Executive Order 12866 requires that all new federal regulations specify the market failure or 

other specific problem that will be addressed by the rulemaking. A market failure occurs when 

the market fails to allocate scarce resources to their highest-valued uses. This can occur for 

several reasons, such as market power, externalities, or information problems. (OMB Circular 

A-4 describes each of these in detail. See http://www.whitehouse.gov/omb/circulars/a004/a4.pdf). Normally in competitive markets, exchanges between self-interested buyers and sellers 

will allocate resources to their highest valued uses. 

The Energy Policy and Conservation Act (EPCA) directs the Department to balance the 

technological and economic challenges related to fuel economy with the nation's need to 

conserve energy. Congress decided that the market would not balance these challenges in the 

best interest of the nation, and that the Department should regulate fuel economy. 
 A-1 

APPENDIX A. Required MPG Levels 

Table A-1 shows the required levels for the alternatives, along with the harmonically weighted 

average mpg. The Act requires that the agency set standards that achieve at least an average 35 

mpg standard for MY 2020. These tables show the progress toward that requirement for each of 

the alternatives. The TC = TB and Technology Exhaustion alternatives already meet 35 mpg by 

MY 2015. The 2% increase alternative makes some progress toward the 35 mpg requirement, 

but you need an average annual increase of 4.5 percent to reach 35 mpg by MY 2020. The 

optimized alternative makes good progress toward the requirement and needs an average yearly 

increase of 2.3 percent to reach 35 mpg by MY 2020. 

Table A-2 shows the incremental percentage increase in the required levels, each year compared 

to the previous year. The MY 2010 baseline for passenger cars is 27.5 mpg, and the MY 2010 

baseline for light truck is the unreformed standard for MY 2010 of 23.5 mpg. The MY 2010 

combined harmonically average baseline for passenger cars and light trucks is 25.34314 mpg, 

based on a 50/50 split for passenger car and light truck sales for MY 2010. The five year 

increase is the average yearly increase. In a formula it is (regulation mpg/baseline mpg)^(1/5). 

In simple terms, for the Optimized (7%) alternative, taking the MY 2010 passenger car baseline 

of 27.5 * 1.054 * 1.054* 1.054* 1.054* 1.054 = 35.77, the mpg needed to be achieved in MY 

2015. 
 A-2 

Table A-1 

Required mpg Levels by Alternative 

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

25% Below Optimized 29.6 30.3 31.7 32.7 33.9 

Optimized (7%) 31.2 32.8 34 34.8 35.7 

25% Above Optimized 32.8 35.3 36.1 36.8 37.5 

50% Above Optimized 34.3 37.8 38.5 38.9 39.5 

Optimized (3%) 37.1 39.1 39.3 40.7 40.9 

TC = TB 37.5 42.7 43 43.1 43.3 

Technology Exhaustion 38.6 45.4 48.9 50.1 52.6 

 

Light Trucks 

25% Below Optimized 24.9 26 27.5 27.5 27.5 

Optimized (7%) 25 26.4 27.8 28.2 28.6 

25% Above Optimized 25.1 26.9 28 28.8 29.8 

50% Above Optimized 25.3 27.3 28.3 29.5 30.9 

Optimized (3%) 25 26.4 28 28.5 29 

TC = TB 25.6 28.1 28.8 30.8 33.1 

Technology Exhaustion 25.9 28.6 32.2 33.1 34.7 

Harmonic Average mpg 

PC+LT MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 

25% Below Optimized 27.1 28.0 29.4 29.8 30.2 

Optimized (7%) 27.8 29.3 30.6 31.0 31.6 

25% Above Optimized 28.5 30.6 31.5 32.2 33.0 

50% Above Optimized 29.2 31.7 32.6 33.4 34.5 

Optimized (3%) 30.0 31.5 32.6 33.3 33.7 

TC = TB 30.6 33.9 34.4 35.7 37.3 

Technology Exhaustion 31.1 35.1 38.7 39.6 41.4 
 A-3 

Table A-2 

Year by Year Percentage Increase 

In Required mpg and 5 Year Annual Average213

Passenger Cars MY 2011 MY 2012 MY 2013 MY 2014 MY 2015 5 years 

25% Below Optimized 7.6% 2.4% 4.6% 3.2% 3.7% 4.3%

Optimized (7%) 13.5% 5.1% 3.7% 2.4% 2.6% 5.4%

25% Above Optimized 19.3% 7.6% 2.3% 1.9% 1.9% 6.4%

50% Above Optimized 24.7% 10.2% 1.9% 1.0% 1.5% 7.5%

Optimized (3%) 34.9% 5.4% 0.5% 3.6% 0.5% 8.3%

TC = TB 36.4% 13.9% 0.7% 0.2% 0.5% 9.5%

Technology Exhaustion 40.4% 17.6% 7.7% 2.5% 5.0% 13.8%

 

Light Trucks 

25% Below Optimized 6.0% 4.4% 5.8% 0.0% 0.0% 3.2% 

Optimized (7%) 6.4% 5.6% 5.3% 1.4% 1.4% 4.0% 

25% Above Optimized 6.8% 7.2% 4.1% 2.9% 3.5% 4.9% 

50% Above Optimized 7.7% 7.9% 3.7% 4.2% 4.7% 5.6% 

Optimized (3%) 6.4% 5.6% 6.1% 1.8% 1.8% 4.3% 

TC = TB 8.9% 9.8% 2.5% 6.9% 7.5% 7.1% 

Technology Exhaustion 10.2% 10.4% 12.6% 2.8% 4.8% 8.1% 

 

PC+LT 

25% Below Optimized 6.9% 3.3% 5.1% 1.2% 1.5% 3.6% 

Optimized (7%) 9.8% 5.2% 4.4% 1.6% 1.8% 4.5% 

25% Above Optimized 12.5% 7.1% 3.1% 2.2% 2.7% 5.4% 

50% Above Optimized 15.3% 8.6% 2.6% 2.5% 3.3% 6.4% 

Optimized (3%) 18.4% 5.2% 3.5% 2.1% 1.1% 5.9% 

TC = TB 20.6% 11.1% 1.5% 3.8% 4.4% 8.0% 

Technology Exhaustion 22.8% 12.8% 10.3% 2.2% 4.7% 10.3% 

 

213 The Baseline mpg levels for MY 2010 are assumed to be 27.5 mpg for passenger cars, 23.5 mpg for light trucks 

and a harmonic average of 25.34314 mpg for the combined fleet, assuming a 50/50 split in sales between passenger 

cars and light trucks for MY 2010.