## Final Regulatory Impact Analysis



# Corporate Average Fuel Economy

for MY 2011 Passenger Cars and Light Trucks

Office of Regulatory Analysis and Evaluation National Center for Statistics and Analysis

March 2009TABLE OF CONTENTS

EXECUTIVE SUMMARY ............................................................................................................. i

I. INTRODUCTION ................................................................................................................ I-1

II. NEED OF THE NATION TO CONSERVE ENERGY..................................................... II-1

III. ALTERNATIVES.......................................................................................................... III-1

IV. IMPACT OF OTHER FEDERAL MOTOR VEHICLE STANDARDS ON FUEL

ECONOMY ........................................................................................................................

....... IV-1

V. FUEL ECONOMY ENHANCI NG TECHNOLOGIES AND THE VOLPE MODEL..... V-1

VI. MANUFACTURER SPECIFIC CAFE CAPABILITIES ............................................. VI-1

VII. COST IMPACTS......................................................................................................... VII-1

VIII. BENEFITS.................................................................................................................

. VIII-1

IX. NET BENEFITS AND SE NSITIVITY ANALYSES ................................................... IX-1

X. PROBABILISTIC UNCERTAINTY ANALYSIS............................................................. X-1

XI. REGULATORY FLEXIBILITY ACT AN D UNFUNDED MANDATES REFORM ACT

ANALYSIS.......................................................................................................................

......... XI-1i



### EXECUTIVE SUMMARY

This assessment examines the costs and benef its of improving the fuel economy of passenger cars and light trucks for model year (MY) 2011. 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 othe r societal benefits such as improved energy security and reduced emissions of pollutants and greenhouse gases 1

.

In the previous rulemaking, the agency reform ed the corporate average fuel economy (CAFE) standards for light trucks with a si ze-based standard based on footprint 2 . 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. Individual manufacturers will be required to comply with a single fuel economy level that is based on the distributi on of its production among the footprints of its vehicles. Although the same reformed CAFE scheme is required for both passenger cars and light trucks, they are established with diffe rent continuous mathematical functions specific to their design capabilities.

The final rule is the “Optimized (7%)” alternative. In this alternative the agency uses a 7 percent discount rate to value intra-ge nerational future benefits and costs and sets the required mpg levels where marginal costs equal marginal benefits . It is one of eight alternatives examined in the analysis. We also examined an optimized scenario when discounting intra-generational future benefits and costs at 3 percent “Optimi zed (3%)”. In all of the alternatives, intergenerational 3 benefits from future carbon dioxide reducti ons are discounted at 3 percent. When discussing an alternative we provide the discount rate in parenthesi s afterwards to keep track of
which alternative we are discussi ng. In general order of increasi ng stringency (see Table 1), the
seven scenarios examined are:

1: “25% Below Optimized (7%)”: This alte rnative mirrors the absolute difference in mpg derived from the 25% Above Optimized scenar io in going the same mpg amount below the Optimized 7% alternative 2: “Optimized (7%)”: An incr ease in the standard based upon av ailability of technologies and a marginal cost/benefit analysis. The mpg levels are set using a 7 percent discount rate for
benefits. 3: “25% Above Optimized (7%)”: This altern ative looks at the mpg levels of the Optimized (7%) and the Total Cost Equals Total Benefit (7 %) alternative and picks mpg levels that are 25 percent of that difference.

1 This analysis does not contain NHTSA’s assessment of th e potential environmental impacts of the final rule for purposes of the National Environmental Policy Act (NEPA), 42 U.S.C. 4321-4347.

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 widt h (the distance between the centerline of the tires) of the vehicle (in square feet).

3 Inter-generational benefits, which include reductions in the expected future economic damages caused by increased global temperatures, a rise in sea levels, and other project ed impacts of climate change , are anticipated to extend over a period from approximately fifty to two hundred or more years in the future, and will thus be experienced primarily by generations that are not now living.ii

4: “50% Above Optimized (7%)”: This altern ative looks at the mpg levels of the Optimized (7%) and the Total Cost Equals Total Benefit (7 %) alternative and picks mpg levels that are 50 percent of that difference. 5: “Optimized (3%)”: An incr ease in the standard based upon av ailability of technologies and a marginal cost/benefit anal ysis, except that the mpg levels are set using a 3 percent discount rate
for benefits. 6: “Total Costs Equal Total Benefits (7%)”: An increase in the standard to a point where essentially total costs of the tec hnologies added equals total benefits . In this analysis, for brevity, at times it is labeled “TC = TB (7%)”. 7: “Technology Exhaustion (7%)”: An increase in the standard based upon the maximum usage (based on NHTSA’s perspective) of available tec hnologies, disregarding the cost impacts.

Table 1 shows the agency’s projection of the act ual harmonic average that would be achieved by the manufacturers, assuming those manufacturer s whose plans were above the requirements would achieve those higher levels. Table 1 also shows the estimated required levels. All of the tables in this analysis compare an adjusted baseline to the projected achieved harmonic average.

Benefits : Benefits are determined mainly from fuel savings over the lifetim e of the vehicle, but
also include externalities such as reductions in criteria pollutants. Table 3 provides those estimates on an industry-wide basis.

Costs : Costs were estimated based on the specific technologies that we re applied to improve each manufacturer’s fuel economy up to the leve l required under each alternative. Table 2 provides those cost estimates on an average per-vehicle basi s, and Table 3 provides those
estimates on a fleet-wide basis in millions of dol lars. Most costs are not discounted because they occur at the time of purchase.

Net Benefits : Table 3 compares societal costs and soci etal benefits of each alternative.

Fuel Savings : Table 4 shows the lifetime fuel sa vings in millions of gallons.

Total Benefits are significantly affected by the decision to disc ount future fuel savings by a 7 percent or 3 percent discount ra te. Based on a marginal cost/marginal benefit analysis, the projected achieved levels in Table 1 are 0.3 mpg higher for the Optimized (3%) scenario than the Optimized (7%) scenario for passenger cars and essentia lly the same mpg level for light trucks.iii

Table 1
Alternative CAFE Levels

MY 2011 (in mpg)

Projected Harmonic Average
for the Fleet 4 Estimated Required Average
for the Fleet Passenger Cars 25% Below Optimized (7%) 30.7 29.9 Optimized (7%) 30.7 30.2 25% Above Optimized (7%) 30.8 30.5 50% Above Optimized (7%) 31.0 30.9 Optimized (3%) 31.0 31.2 TC = TB (7%) 31.2 31.5 Technology Exhaustion (7%) 32.4 35.5

Light Trucks 25% Below Optimized (7%) 23.2 24.1 Optimized (7%) 23.2 24.1 25% Above Optimized (7%) 23.2 24.2 50% Above Optimized (7%) 23.2 24.2 Optimized (3%) 23.2 24.1 TC = TB (7%) 23.2 24.3 Technology Exhaustion (7%) 23.7 29.0

4 The values represent weighted mpg values that we predic t will be achieved by the fleet. For most manufacturers, the mpg values represent the higher of the manufacturer’s plans and the alternative level of the standard. Some manufacturers are assumed to pay fines in lieu of achieving compliance with their required level.iv

Table 2 Average Incremental Cost
Per Vehicle

MY 2011 (2007 Dollars)

Passenger Cars Cost per vehicle 25% Below Optimized (7%) 40 Optimized (7%) 64 25% Above Optimized (7%) 120 50% Above Optimized (7%) 193 Optimized (3%) 220 TC = TB (7%) 310 Technology Exhaustion (7%) 1,445

Light Trucks 25% Below Optimized (7%) 126 Optimized (7%) 126 25% Above Optimized (7%) 169 50% Above Optimized (7%) 169 Optimized (3%) 126 TC = TB (7%) 242 Technology Exhaustion (7%) 1,177v

Table 3
Present Value of Lifetime Societal Benefits 5

, Incremental Total Costs by Societal Perspective, and Net Total Benefits by Alternative (Millions of 2007 Dollars)

Passenger Cars Societal Benefits Societal Costs Net Total Benefits 25% Below Optimized (7%) 786 291 496 Optimized (7%) 1,027 496 531 25% Above Optimized (7%) 1,332 1,003 329 50% Above Optimized (7%) 1,773 1,630 143 Optimized (3%) 2,647 1,820 828 TC = TB (7%) 2,487 2,619 (132) Technology Exhaustion (7%) 6,406 11,907 (5,501)

Light Trucks 25% Below Optimized (7%) 921 649 272 Optimized (7%) 921 649 272 25% Above Optimized (7%) 989 915 75 50% Above Optimized (7%) 989 915 75 Optimized (3%) 1,176 649 527 TC = TB (7%) 1,189 1,391 (202) Technology Exhaustion (7%) 2,950 6,214 (3,264)

Passenger Cars and Light Trucks Combined 25% Below Optimized (7%) 1,707 940 767
Optimized (7%) 1,948 1,145 802
25% Above Optimized (7%) 2,321 1,918 403
50% Above Optimized (7%) 2,763 2,545 218
Optimized (3%) 3,824 2,469 1,355
TC = TB (7%) 3,676 4,009 (334)
Technology Exhaustion (7%) 9,356 18,120 (8,765)

5 These benefits are considered from a “societal persp ective” because they include externalities. They are distinguished from a consumer perspective, because cons umers generally would not thin k about the value of carbon dioxide, etc.vi

Table 4 Savings in Millions of Gallons of Fuel
Undiscounted Over the Lifetime of the Model Year

MY 2011

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 352 424 776 Optimized (7%) 463 424 887 25% Above Optimized (7%) 598 456 1,054 50% Above Optimized (7%) 794 456 1,250 Optimized (3%) 946 424 1,371 TC = TB (7%) 1,121 567 1,687 Technology Exhaustion (7%) 2,982 1,420 4,402I-1



### I. INTRODUCTION

The purpose of this study is to analyze the eff ects of changes in the fuel economy standards for passenger cars and for light trucks for MY 2011. 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), setti ng 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. Simila r to this report, a Final Regulatory Impact Analysis accompanied that final rule. 6 Much of the technical and cost information used in the 2006 analysis was taken from the findings in the National Academy of Sciences study 7 published in January 2002.

The new attribute-based Reformed CAFE system is based on the vehicle footprint (wheel base 8 x average wheel track width 9 ). The anticipated advantages of the ne w reformed CAFE system are:

First, the energy-saving potential of the CAFE program was hampered by the original regulatory
structure. Manufacturers who o ffer predominately small vehicles had little or no regulatory incentive to enhance fuel economy, because their vehi cles 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, resp ectively, 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 se gments and their fuel economy performance may reduce the incentive to design vehicles which are functionally similar to passenger cars but are
classified as li ght 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, manu facturers may offer small vehicl es to offset their offerings of large vehicles. The resulting in crease 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 study 10 have suggested that if downweighting were concentrated on the heaviest vehicles in the fleet, there could be a small fl eetwide safety benefit, but downweighting of passenger cars and the lighter light trucks would increase fatalities.

6 “Final Regulatory Impact Analysis, Corporate Average Fuel Economy and CAFE Reform for MY 2008-2011 Light Trucks”, March 2006, Docket No. 24309-5.

7 “Effectiveness and Impact of Corp orate Average Fuel Economy (CAFE) St andards”, National Research Council,

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

8 “Wheel base” is essentially the dist ance between the centers of the axles.

9 “Track width” is the lateral distan ce between the centerline of the tires.

10 “Vehicle Weight, Fatality Risk and Crash Compatibilit y 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 rela tes to the adverse economic impacts that may result from such future increases in the stringe ncy of CAFE standards. Rapid increases in the
level of the CAFE standard could have substa ntial economic consequences on manufacturers, especially those full-line manufacturers with prod uct 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 stri ngent under the or iginal 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 pass enger car CAFE standards for each model year, but sets a default standard of 27.5 mpg. NHTSA ha s 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 equa lly to passenger cars as to light trucks. NHTSA was unwilling to raise the passenger car CA FE standard without also reforming it, because of the same fuel savings, safety, and econo mic concerns that led it to reform the light
truck CAFE standards.

In December 2007, Congress passed the Energy Inde pendence 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 manufact urers 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. EISA additiona lly gives NHTSA authority to reform passenger car CAFE, allowing the agency to set standards fo r those vehicles according to an attribute-based
mathematical function as it curre ntly does for light trucks.

On May 2, 2008, NHTSA published a notice of pr oposed rulemaking (NPR M) in the Federal Register (73 FR 24352) proposing standards for model years (MY) 2011-2015, the maximum number of model years under EISA for which NHTSA can establish st andards in a single rulemaking. A Preliminary Regulatory Impact Analysis (PRIA) accompanied the NPRM. 11 While a large number of alternatives were examined, the proposed required mpg levels (comparable to Table 1) for the proposed al ternative (labeled as Optimized 7%) were:

11 “Preliminary Regulatory Impact Analysis, Corporate Average Fuel Economy for MY 2011-2015 Passenger Cars and Light Trucks” April 2008, NHTSA, (Docket No. 2008-0089-3.1)I-3

Table I-1 Proposed Required Levels

MY 2011 MY 2012 MY 2013 MY 2014 MY 2015

Passenger Cars 31.2 32.8 34 34.8 35.7
Light Trucks 25.0 26.4 27.8 28.2 28.6

These proposed required levels we re higher than the agency estim ated the harmonic level of the fleet would be in those years, since some manufacturers would not be able to achieve those
levels or would choose to not meet those levels and would pay a penalty for not complying. The
lower achievable levels served as the basis for many of the analyses in the PRIA. New vehicle price increases included technology costs and penalt ies for consumers, but benefits only included fuel savings up to the achieved levels.

The dual fuel incentive program, through which manu facturers 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 progr am designed to increase the availability of
alternative fuel vehicles.

Throughout this analysis, unless ot herwise noted, the agency has not considered the ability of
manufacturers to use credits or cr edit trading in achieving the a lternative fuel economy levels.

Throughout this document, confidential inform ation is presented in brackets [ ].

Additionally, by way of background, the agency notes that in mid-October 2008, the agency completed and released a final environmental impact statement in anticipation of issuing standards for those years. Based on its considerat ion of the public comments and other available information, including information on the fina ncial condition of the automotive industry, the agency adjusted its analysis and the standards and prepared a final rule and Final Regulatory Impact Analysis (FRIA) for MYs 2011-2015. On November 14, the Office of Information and Regulatory Affairs (OIRA) of th e Office of Management and Budge t cleared the rule and FRIA
as consistent with the Order. 12 However, issuance of the final rule was held in abeyance. On January 7, 2009, the Department of Transportati on announced that the final rule would not be issued, saying:

The Bush Administration will not fina lize its rulemaking on Corporate Fuel Economy Standards. The recent financial difficulties of the automobile industry will require the next administration to conduct a thorough review of matters affecting the industry, including how to effectively implement the Energy Independence and Security Act of 2007 (EISA). The National Highway Traffic

12 Record of OIRA’s action can be found at http://www. reginfo.gov/public/do/eoHist ReviewSearch (last visited March 8, 2009). To find the report on the clearance of the draft final rule, select “Department of Transportation” under “Economically Significant Reviews Completed” and select “2008” under “Select Calendar Year.”I-4

Safety Administration has done significan t work that will position the next Transportation Secretary to finalize a rule before the April 1, 2009 deadline. 13

In light of the requirement to prescribe st andards for MY 2011 by March 30, 2009 and in order to provide additional time to consider issues concerning the analysis used to determine the appropriate level of standards for MYs 2012 a nd beyond, the President issued a memorandum on January 26, 2009, requesting the Secretary of Transportation and Administrator 14 of the National Highway Traffic Safety Administration NHTSA to di vide the rulemaking into two parts: (1) MY 2011 standards, and (2) sta ndards for MY 2012 and beyond.

The request that the final ru le establishing CAFE standards for MY 2011 passenger cars and light trucks be prescribed by March 30, 2009 was based on several factors. One was the requirement that the final rule regarding fuel economy standards for a given model year must be adopted at least 18 months before the beginning of that model year (49 U.S.C. 32902(g)(2)). The other was that the beginning of MY 2011 is c onsidered for the purposes of CAFE standard setting to be October 1, 2010. As part of that final rule, the Presiden t requested that NHTSA consider whether any provisions regarding preemption are cons istent with the EISA, the Supreme Court's decision in Massachusetts v. EP A and other relevant provisions of law and the policies underlying them.

The President requested that, before promulgati ng a final rule concerni ng the model years after model year 2011, NHTSA

[C]onsider the appropriate legal factor s under the EISA, the comments filed in response to the Notice of Proposed Rule making, the relevant technological and scientific considerations, and to the extent feasible, the forthcoming report by the National Academy of Sciences ma ndated under section 107 of EISA.

In addition, the President requested that NHT SA further consider whether any provisions regarding preemption are appropriate under applicable law and policy.

In keeping with the President’s remarks on Janu ary 26 for new national po licies to address the closely intertwined issues of energy independence, energy security and climate change, and for
the initiation of serious and sustained domestic and international action to address them, NHTSA will develop CAFE standards for MY 2012 and beyond only after collecting new information, conducting a careful review of technical and economic inputs a nd assumptions, and standard setting methodology, and completing new analyses.

For MY 2011, however, time limitations precluded th e adoption of this approach. As noted above, EPCA requires that standards for that mode l year be established by the end of March of this year. Thus, immediate decisions had to be made about the establishment of the MY 2011
standards. There was insufficient time between the issuance of the Pres ident’s memorandum in late January and the end of Marc h to revisit and, if and as appr opriate, revise the extensive and

13 The statement can be found at http://www.dot.gov/affairs/ dot0109.htm (last accessed February 11, 2009).

14 Currently, the National Highway Traffic Safety Administration does not have an Administrator. Ronald L. Medford is the Acting Deputy Administrator.I-5

complex analysis in any substantively significan t way. This is particularly so given the requirement under EPCA to consult with th e Environmental Protection Agency and the Department of Energy on these complicated a nd important technical matters. Decisions regarding those matters potenti ally affect not just NHTSA’s CAFE rulemaking, but also programs of other departments and agencies. Accordingly, the methodologies, economic and technological inputs and decision-ma king criteria used in this rule are necessarily largely those developed by NHTSA in the fall of 2008.

In looking ahead to the next CAFE rulema king, the agency emphasizes that while the methodologies, economic and technological inputs a nd decision-making criteria used in this rule were well-supported choices for the purposes of the MY 2011 rulemaking, they were not the only reasonable choices that the agency could have made for that purpose. Many of the key aspects of this rulemaking reflect decisions am ong several reasonable alternatives. The choices made in the context of last fall may or may not be the choices that will be made in the context of the follow-on rulemaking.

The deferral of action on the CAFE standards for the years after MY 2011 provides the agency with an opportunity to revi ew its approach to CAFE st andard setting, including its methodologies, economic and technological inpu ts, and decision-making criteria. It is reasonable to anticipate that this process may l ead to changes, given the further review and analysis that will be conducted pursuant to the President’s request, and given the steady and potentially substantial evolution in technical and policy factors releva nt to the next CAFE rulemaking. These factors include, but are not limited to, energy and climate change needs and policy choices regarding goals and approaches to achieving them, developments in domestic legislation and international ne gotiations regarding those goals and approaches, the financial health of the industry, technologies for reduci ng fuel consumption, fuel prices, and climate change science and damage valuation.

The goal of the review and re-evaluation will be to ensure that the approach used for MY 2012 and thereafter produces standard s that contribute, to the ma ximum extent possible under EPCA/EISA, to meeting the energy and environm ental challenges and goals outlined by the President. We will seek to craft our program with the goal of creating the maximum incentives for innovation, providing flexibility to the regul ated parties, and meeting the goal of making substantial and continuing reductions in the cons umption of fuel. To that end, we are committed to ensuring that the CAFE program for be yond MY 2011 is based on the best scientific, technical, and economic information available, and that such information is developed in close coordination with other federal agencies and our stakeholders, includi ng the states and the
vehicle manufacturers.

We will also re-examine EPCA, as amende d by EISA, to consider whether additional opportunities exist for achieving the President’s goals. For exampl e, EPCA authorizes, within relatively narrow limits and subjec t to making specified findings, for increasing the amount of civil penalties for violating the CAFE standards. 15 Further, while EPCA prohibits updating the

15 Under 49 USC 32904(c), EPA must “use the same procedures for passenger automobiles the Administrator used for model year 1975 (weighted 55 percent urban cycle and 45 percent highway cycle), or procedures that give comparable results.”I-6

test procedures used for measuring passenger car fuel economy, it places no such limitation on the test procedures for light trucks. 16 If the test procedures used fo r light trucks were revised to provide for the operation of air conditioning during fuel economy testing, vehicle manufacturers would have a regulatory incentive to increase the efficiency and reduce the weight of air conditioning systems, thereby reducing fuel consumption and tailpipe emissions of CO 2

.

In response to the President’s request that NHTSA consider wh ether any provisions regarding preemption are consistent with EISA, the Supr eme Court’s decision in Massachusetts v. EPA and other relevant provisions of law and th e policies underlying them, NHTSA has decided not to include any provisions addressing preemption in the Code of Federal Regulations at this time. The agency will re-examine the issue of preempti on in the content of its forthcoming rulemaking to establish Corporate Average Fuel Econom y standards for 2012 and later model years.

16 49 USC 32912(c).I-7

Response to Docket Comments
Comments to the NPRM were submitted to www.regulations.gov to NHTSA docket 2008-0089. This section summarizes those comments by issu e and provides NHTSA’s response to them. The issues are listed in alphabe tical order (by our re ference method) and the table of contents helps the reader find issues.

Table I-2 Docket Issues and Page Numbers Docket Issue Page # Docket Issue Page # Baseline I-4 Learning Curve I-32 Congestion, Crashes and Noise

Costs I-6 Marginal Cost/Marginal Benefit I-32

Consumer Benefits from Additional Driving I-8 Market Failure I-33

Cost and Effectiveness of Technologies I-9 On-road Fuel Economy Adjustment I-34

Discount Rates I-10 Payback Period I-34 Emissions savings per ton – Value
of Carbon I-19 Price of Gasoline I-36

Emissions Worldwide vs. U.S. I-21 Product Restrictions I-44

Emissions Growth Rate over Time I-22 Rebound Effect I-44

Emissions Values for Criteria
Pollutants I-22 Regulatory Flexibility Analysis I-46

Externalities – Monopsony I-25 Restrict Product Offerings I-46 Externalities – Supply Disrupti on I-25 Retail Price Equivalent Multiplier I-47

Externalities – Military Costs I-26 Sales Impact and Related Employment Impact I-50

Financial Impact I-27 Safety Standards Impact on Weight See Chapter IV Inequality of Impacts on Smaller
Manufacturers I-29 Size/Safety Impacts See Chapter IV Leadtime I-31 Uncertainty Analysis I-52

Baseline

In the NPRM, the agency used an “adjusted” ma nufacturer’s product plans as a baseline. If a manufacturer’s product plans were equal to or above the MY 2010 CAFE requirements, then the manufacturer’s product plans were their baseline and costs and be nefits were estimated as an increment above that level. However, if the manufacturer’s product plan s were below the level of the MY 2010 standard, then te chnologies were added to their plans to bring them up to the level of the MY 2010 standard and this “adjust ed” baseline became their baseline for the analysis.

Comment: Alliance, 2008-0089-0179.1, P7I-8

NHTSA should use as a current baseline MY 2006 us ed by Sierra Research Inc., not a projected baseline. The current baseline has comple te data. Manufacturers who planned for new government mandates are penalized and thei r costs are underestimated. NHTSA has underestimated the increase in vehicle pric es by $260 per car and $920 per truck.

Agency response: NHTSA develops an adjusted baseli ne because the costs and benefits of reaching the MY 2010 standards were already acc ounted for in prior rulemakings, just as the costs and benefits of reaching the MY 2011 st andards are accounted for in the current rulemaking. To avoid double-counting the costs to manufacturers (and the be nefits to society) required to meet the MY 2010 standards, NHTSA develops this adjusted baseline, which the agency then uses in analyzing the MY 2011 standards.

Comment: Alliance, 2008-0089-0179.1, Attachment 2 P4-5

NHTSA should consider a constant model mix, ra ther than the projected changing model mix
from the manufacturers. Model mix creates significant uncertainty. Consumer preference ultimately determines model mix, and since forecasts made 8 years before are inherently unreliable, there is significant uncertainty in the use of manufacturers plans and model mix
estimates.

Agency response: We agree there is uncertainty in th e future model mix, but we are trying to estimate the incremental impact of the fuel economy standards, not the future of the automobile industry sales. The format of the standards, w ith target goals based on footprint, allows the
manufacturer’s standard to float with their sales mix and makes mode l mix less of an issue.

Comment: Union of Concerned Sc ientists, 2008-0089-0201.13, P3

The Union of Concerned Scientists uses a base line scenario correspondin g to laws on the books
at the time.

Agency response: Without the manufacturers’ confidentia l plans, this might be the most reasonable assumption. However, we have the ma nufacturers’ confidential plans and we prefer our approach for purposes of this rulemaking.

Comment: Mercatus Center, George Mason University, 2008-0089-216.1

Raise the baseline forecast of fuel economy of th e vehicle fleet to reflect the recent increase in fuel economy in response to higher fuel prices. The Mercatus Center discusses whether the fuel savings calculated in the CAFÉ model correctly reflect the gains that would come from the proposed regulation. Noting current market fo rces are driving fuel economy higher, the comment argues that NHTSA’s analysis underestim ates the baseline level of future fuel efficiency, and consequently overestimates the am ount of fuel saved by ra ising CAFE standards.

Agency response: The approach suggested by the Mercatus Center could lead to significant speculation and it would be very hard to justif y any particular baseline for the future.

Congestion, Crashes and Noise Costs –I-9

In the NPRM the agency stated that increased vehicle use associated with the fuel economy
rebound effect can also contribute to increased traffic congestion, motor vehicle crashes, and highway noise. In the NPRM, NHTSA relied on estimates developed by the Federal Highway Administration (FHWA) of the increased exte rnal costs of congestion, accidents (property damage and injuries), and noise costs cause d by added driving due to the rebound effect. 17 NHTSA translated these marginal estimates in the tables and then the marginal costs were multiplied by the expected annual increases in automobile and light truck use from the rebound effect to yield the estimated in creases in congestion, accident, a nd noise externality costs during each future year. These estimates are intended to measure the increases in costs due to these externalities caused by automobiles and light truc ks that are borne by persons other than their drivers, or “marginal” external costs. The only new comments were on congestion.

Comment: Alliance, 2008-0089-179.1 The Alliance submitted an analysis by NERA Econom ic Consulting that essentially argued that
NHTSA had underestimated the increased costs fr om congestion, crashes, and noise. The NERA analysis argued that FHWA’s estimate was “based on a value of $12.38 per vehicle hour (in 1994 dollars),” while NHTSA used a value of $ 24 per vehicle hour “to value time savings it estimates would result from fewer fill-ups as a result of higher MPG and increased range for a tank of fuel.” Thus, the NERA analysis c oncluded that NHTSA had overvalued the time savings, which NERA seemed to attribute to its belief that NHTSA does not value time spent in traffic congestion “at least as highly as tim e spent in service stat ions while filling up.” 18 Thus, the NERA analysis argued that congestion costs per mile woul d increase by about 68 percent if NHTSA had updated FHWA’s estimates in a “cons istent” manner with “NHTSA’s valuation of time savings for vehicle occupants in another part of its analysis.”

Agency response: The agency does not intend to imply that time spent during one activity is more valuable than time spent during another activ ity. What has occurred is that in 2003 the Department of Transportation updated its estimat e of the value of time. The 1997 FHWA report does not include the more recent update. However, the agency cannot go back to every reference it relies on and redo those analyses. This is not the only area that the Department or others have updated their estimates. For example, DOT has u pdated its estimate of the value of a statistical life, which affects crash costs. The agency does not have the wherewithal to accomplish such a time consuming task. The typical method is to update the dollars estimates to $2007 by using the
Gross Domestic Product price index.

Comment: The NERA analysis also ar gued that the baseline 1997 congestion values “should be adjusted upward even more to reflect increasing levels of c ongestion between then and now and the further increases likely” within the lifetimes of the vehicles, the basis for NHTSA’s cost analysis. The analysis stated that this was because “With higher baseline congestion, the marginal impact of additional VMT will in crease because congestion, like other queuing phenomena, increases at an increasing rate as capacity utilization grows.”

17 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 April 20, 2008).

18 NERA appears to suggest that time spent in service stati ons while filling up includes the fact that “stops at service stations often serve multiple purposes, not just refueling.” NERA then appears to suggest that people feel similarly about time spent in traffic congestion.I-10

Comment: The Mercatus Center (2008-0089-216.1) focused only on congestion costs, and commented that NHTSA should consider “The possibi lity that the cost of increased congestion, a product of the ‘rebound effect,’ does not take into account likely increasing marginal costs as
considered in NHTSA’s model.” The commente r stated that NHTSA’s estimates “implicitly assume a constant marginal cost of congestion ac ross all possible total quan tities of vehicle miles driven for each vehicle category.” However, it cited the FHWA study as stating that congestion cost impacts are “extremely sensitive” to peak versus off-peak traffic periods. Thus, the commenter argued, if the costs can vary within a day (as during peak and off-peak periods), they must certainly vary across years, if the total amo unt of traffic varies acr oss years as well. In essence, if VMT increases, total congestion an d the marginal cost of congestion must also increase, all other things held constant. However, if all other things are not held constant, e.g. if new roads are built to handle increasing traffic, the commenter argued that “total conges tion does not necessarily increase with increases
in total vehicle miles driven.” The commenter argued that NHTSA should include an estimate of the costs of building additional roads or altering existing ones to mitigate congestion due to the
rebound effect. That estimate should include accounting for “the increasing difficulty of building a new road in an urbani zed area,” which the commenter stated is “probably one of the best examples of an activity that has rapidl y increasing marginal costs,” as well as the environmental costs of building new roads, i.e. costs due to sprawl. Th e commenter asserted that “It is incumbent upon NHTSA and the Environmenta l Protection Agency to produce an inclusive
estimate of the costs of the rebound effect—one th at either includes both increasing marginal cost of congestion and the cost of the new roads that will lead to increased congestion.”

Agency response: The agency does not know the relations hip between potential increases in VMT and congestion. The FHWA margin al costs were projected for future requirements of highways up through year 2000 using the base period of 1993-1995 and a national value of
VMT. There is no other known similar estimate of highway costs beyond 2000. Neither is there an estimate of the relationship between the rebound effect and the amount of congestion for years beyond 2000, i.e. congestion is not assumed to be linear with VMT. Similarly, it is not clear how the additional roads, if built after 2000, would offset conge stion and future year costs. Once again, the agency simply does not have the re sources or time to redo and update these very complicated analyses that could make very minor differences in the level of the standard.

NHTSA believes it is reasonable to assume that additional vehicle use due to the fuel economy rebound effect will be distributed over the day and among locations in much the same way as current travel is distributed. As a consequen ce, the FHWA estimates of congestion costs from increased vehicle use are likely to provide more accurate estimates of the increased congestion costs caused by added rebound-effect driving than are the estimates submitted by commenters, which apply to peak travel periods and locati ons that experience high traffic volumes. Thus, NHTSA has continued to rely upon the FHWA va lues to estimate the increase in congestion costs likely to result from added rebound-effect driving.

Updated to 2007 dollars, FHWA’s “Middle” estim ates for marginal congestion, accident, and noise costs caused by automobile use amount to 5.4 cents, 2.3 cents, and 0.1 cents per vehiclemile (or 7.8 cents per vehicle-mile in total), wh ile costs for light trucks are 4.8 cents, 2.6 cents,I-11

and 0.1 cents per vehicle-mile (7.5 ce nts per vehicle-mile in total). 19 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.

Consumer Benefits from additional driving

In addition to the benefits that drivers rece ive from increased vehi cle use due to the rebound effect, the agency argued in the NPRM that improving the fuel economy of passenger cars and light-duty trucks may also increase their driv ing range before they require refueling. By reducing the frequency with whic h drivers typically refuel thei r vehicles, and by extending the upper limit of the range they can travel before requiring refueling, improv ing fuel economy thus provides some additional benefits to their owners.

Comment: The Alliance 2008-0089-0179.1, P8, P36, Attachment 2 P5, P103-107
, stated that “NHTSA incorrectly assumes that its new fuel economy standards will improve vehicle range and thus reduce the number of times a vehicle owner would have to refill the tank (creating consumer benefits).” The Alliance comments fo cused on two points: one, that analysis by
Sierra Research demonstrates “the complete absence of any relationship between fuel economy and range in the light truck fleet ,” and two, that manufacturers “d esign fuel-storage capacity to achieve the basic range requirements consumer s demand,” and will reduce the space necessary for fuel tanks to keep vehicle ra nges to 300-400 miles in order to de vote it to other uses (such as increasing cargo space) if fuel economy levels rise.

Agency response : As discussed in the PRIA, “...if manufacturers re spond to improved fuel economy by reducing the size of fu el tanks to maintain a consta nt driving range, the resulting cost saving will presumably be reflected in lowe r vehicle sales prices.” Or if a manufacturer decides to increase trunk space, they have implicitly assumed that trunk space is of more value to their consumers than fewer refills. Either way, th e benefit or the opportunity for benefit is there. This implies that NHTSA’s estimate of the value of increased refueling range will underestimate the true benefits from the resulting ch anges in vehicle attributes or prices.

Additionally, there is a relations hip between typical gasoline e ngines and hybrids in terms of vehicles with better fuel economy having more range . It was intuitively believed that the market condition was such that drivers would indeed very much like to have a much lower frequency of visits to fuel stations than every 300-400 miles. A review of current hybr id specifications in Table I-3 shows that higher ranges are provided in these vehicles.

Table I-3 Hybrid Vehicle Range Specifications

Vehicle Specified Range (miles) Rated Fuel Economy (mpg) 2008 Honda Civic Hybrid 650 47/48 2007 Honda Accord Hybrid 600 29/37

19 Id ., at Tables V-22, V-23, and V-24 (last accessed October 5, 2008).I-12

2008 Nissan Altima Hybrid 720 42/36 2008 Toyota Prius 547 46 2008 Toyota Camry Hybrid 585 33/34 2008 Ford Escape Hybrid 510 34/30

2007 Lexus RX Hybrid 530 32/27

2008 Mazda Tribute 544 29/34

Cost and effectiveness of technologies

NHTSA developed detailed estimates for the NPRM of the costs and effectiveness of applying fuel economy-improving technologies to vehicle models for use in analyzing the impacts of the
alternative standards considered in this rulemaking. NHTSA expl ained that the NPRM estimates were based on those reported by the 2002 NAS Report analyzing costs and effectiveness for increasing fuel economy, but NHTSA modified t hose costs and effectiveness estimates for purposes of the PRIA as a result of extensive consultations among engineers from NHTSA, EPA, and the Volpe Center. As part of this proc ess, NHTSA also developed varying cost and effectiveness estimates for applying certain fuel economy technologies to vehicles of different sizes and body styles. NHTSA stated that it may adjust these estimates based on comments
received to the NPRM.

NHTSA explained that the technolo gy cost estimates used in the agency’s analysis are intended to represent manufacturers’ di rect 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 we re fully realized.

Comments: Almost every manufacturer commented th at NHTSA had overestimated the benefits of certain technologies or had underestimated the costs of technologi es. Several provided
confidential information of their estimates. Other commenters indicated that NHTSA had
underestimated the benefits of cer tain technologies. The comments are too numerous to include
in this document. Agency response : The agency hired a contractor (Ricar do) to go through all of the technologies and all of the comments and provide their expert opinion on the appropriate usage of technologies and their costs and benefits. The agency worked in consultation with Ricardo to develop the agency’s estimates of technology costs and effectiveness. Costs do change over time and the cost estimates were based on the prices in effect at the time the estimates were made. The agency intends to monitor commodity prices carefully and will adju st affected technology costs as necessary in future rulemakings. Because costs change over time, the agency re-e xamines costs for each rulemaking. See Chapter
V for more information.

Discount rates

Most of the commenters realized that the discoun t rate has a significant imp act on the level of the
standard. The discount rate is used to determin e the present value of future benefits (e.g. fuelI-13

saved over the lifetime of the vehi cle). The agency used a 7 per cent discount rate to determine the proposed CAFE levels, and asked for commen ts about whether a 3 percent discount rate should be used for standard setting purposes. Based on our marginal cost = marginal benefit methodology, discounting by a lower rate results in higher benefits, which allows more
countermeasures to be cost effectiv e and the standard to be higher.

Almost every commenter expressed an opinion about the discount rate. Some argued that there is an intergenerational discount rate that should be applied to benefits like carbon emission reductions that occur over long time frames, like 100 to 150 years. The intergenerational
discount rate could be different th an the conventional discount rate applied to fuel savings (that occur over the next 36 years in the case of li ght trucks). We will always use the term intergenerational to distinguish this long term discount rate from the conventional discount rate we normally use.

Those favoring a 7 percent discount rate include:

Comment: AIAM, 2008-0089-0205.1, Pg. 6 supports the discount rates used by NHTSA. The NAS report assumed discount rates that bracket those considered by NHTSA.

Comment: National Automobile Dealers Associ ation, 2008-0089-223.1, Pg 6-7 stated that a discount rate of at least seven pe rcent (or higher) should be used to estimate the future costs and benefits of the proposed standards. NHTSA should not use the OMB default calculation of the economy-wide opportunity cost of capital. As NHTSA correctly notes, financing rates on motor
vehicle loans are indicative of appropriate discount rates sinc e they reflect the real-world opportunity costs faced by consumers when buying vehicles having greater fuel economy costs
associated with them.

Those favoring a 5 percent discount rate include:

Comment: Consumer Federation of America, 2008-0089-0183, Pg. 52-53 stated that NHTSA should have used 5% (the average of 3% and 7% ). The rate NHTSA uses fails to reflect the importance of fuel savings.

Those favoring the 3 percent discount rate, saying that the discount rate should be based on the social rate of time preference, include: Attorney General of the States, 2008-0089-0199.1, Pg 11
Union of Concerned Sc ientists, 2008-0089-201.1 Air Resources Board, 2008-0089-0173, Pg. 11 Natural Resources Defense Council, 2008-0089 225.1, Pg. 2 and following

Those discussing a lower rate, but no t identifying that rate included:

Comment: Yohe, 2008-0089-139.1 disagrees with NHTSA’s rationale for relying primarily on a 7% discount rate. Commenter argues that public investment should be based on a low discount rate if it complements private i nvestment, since by doing so public in vestment raises the rate of return to private investment, thereby partly offs etting the effect of reduc ed returns to private investment caused by the corporate profits tax. Commenter contends that mitigating greenhouse gas emissions complements private investment more broadly, while at the same time making adaptation to climate change more productive. Commenter observes that the higher average fuelI-14

economy resulting from applying a lower discount rate indicates that the analysis captures some of the value of this complementarity. Commen ter acknowledges that taxes that support public investment generally affect cons umption, but argues that this e ffect is captured in the cost calculation, and states that mitigation offers a co-benefit because it improves the marginal productivity of other private investments. Comm enter also believes the definition of the social rate of time preference to be stated incorrectly and believes “utility” should be substituted for “consumption.”

Comment: Another discount rate was propos ed by Sierra Research, 2008-0089-0046, Page 74, based on an analysis by NERA they use a 12.4% discount rate for futu re fuel savings.
NERA National Economic Research Associ ation, 2008-0089-050, Page 1-7 uses a 12.4% discount rate based on a range of plausible discount rates to be used in an analysis of the operating cost savings from improvements in automotive fuel economy improvements. When purchasing a car, a rational consumer will consider future operating costs and will discount them to present value usi ng a discount rate that will reflect the risk or uncertainty in the value or future operating costs. Consumers will perform this discounting using his or her own private discount rate. Consumers will not use a so cial discount rate that a government agency might use in doing a cost benefit analysis. Nor will consumers use the rate of a new car loan,
which is a known certain rate. Th e operating costs of a vehicle vary with fuel prices and driving patterns, which are much more uncertain. As such, they would consider consumers private discount rate to be higher than the rate of a new car loan. Empirical economic research has consistently demonstrated that consumers use high discount rates when calculating the present value of future cash flows associated with ope rating costs of durable equipment. One study
addressed the discount rate used by consumer with respect to auto mobile in particular. The appropriate discount rate is th e rate that consumers actuall y use when deciding on vehicle purchases. While the discount rate consumers actually use can not be observed, it can be inferred from consumer behavior. Dreyfus and Viscusi (1995) use a hedonic regression model to estimate consumer value for fuel economy impr ovements and the associated discount rate. Dreyfus, M. and Viscusi, W., (1995) Rates of Time Preference and Consumer Valuations of Automobile Safety and Fuel Efficiency , Journal of Law and Economics. Their estimates of the discount rate range from 10.7 to 17.4 percent, depending upon the specif ication selected. The study was based on 1988 data when interest rates were higher and should be adjusted to today’s economic conditions. The nominal yield on Tr easury bonds in 1988 is 8.9 percent. After adjusting for inflation (4.3%) the real rate of growth in treasury bonds was 4.6 percent. Subtracting 4.6 percent from 10.7 – 17.4 percent leaves 6.1 to 12.8% . And after adjusting for interest rates, adding the 10 y ear Treasury bond yield of 2.9 per cent, the rates are 9.0 to 15.7%, the average is 12.4%.

Comment: The Alliance, 2008-0089-0179.1, Pg. 9, 31 supports the 12.4 percent discount rate.

Those discussing the intergenerat ional discount rate commented:

Comment: Yohe, 2008-0089-139.1 recommends that NHT SA apply a lower discount rate to
benefits from future reductions in CO2.

Comment: Mark Eads, 2008-0089-0165.1I-15

Mr. Eads disagrees with NHTSA choice of 7 perc ent discount, both in terms of the magnitude of
the discount rate and in NHTSA’ rationale. He argues that the choices made primarily involve long-term inter-generational environmental benef its and costs rather th an intra-generational
benefits and costs. He advocat es that NHTSA apply a non-constant declining discount rate that begins at 2.6 percent in year one, declining to 0.6 per cent in year 300.

Comment: Prof. Michael Hanemann, Dept. of Agricu ltural and Resource Economics, University of California, Berkeley, 2008-0089-0188, recommends using a discount rate no higher than 4%,
and a rate as low as 2% for sens itivity analysis. It is not clea r whether these rates are to be applied to benefits from future reductions in CO 2 emissions only or to a ll future benefits from lower fuel consumption (presumably the former). Commenter criticiz es 7% and 4% discount rates used by NHTSA and by Nordhaus and Boyer as unjustified for use in assessing benefits from reducing threat or severity of climate ch ange, and briefly cites some research suggesting
that discount rates below 3% ar e appropriate for discounting futu re climate-related damages.

Comment: Attorney General of the State of California, 2008-0089-0199.4 provides no clear recommendation for action by NHTSA; but provides a detailed presentation from Hanemann to
an unidentified audience.

Comment: Center for Biological Diversit y, 2008-0089-222.1, Pg. 5, 8 stated that NHTSA’s
discount rate value is too hi gh, and NHTSA didn’t use a reasona ble range of values in the sensitivity analysis. Stern (2007) estimates the discoun t rate at lower than 1%. A ny calculations performed under a
selected discount rate for societal benefits mu st be compared to the same calculations under standard inflationary discount, but without discounting societal be nefits to future generations. Stern (2006) notes the discount rate can be negative (in the context of discounting CO2 emissions).

Comment: Environmental Defense Fund, 2008-0089- 224.1, Pg. 1 recommends use of a 3 percent discount rate for standard setting, with a sensitivity an alysis using a 0.5 and 1 percent rate. Use of a high discount rate does not re flect the intergenerational impacts of CAFE implementation. One of the major benefits of the CAFE standards, in addition to increasing energy security and energy efficiency, is sign ificantly reducing global warming pollution from
automobiles. Because the benefits of reduc ing climate change will occur over multiple generations, we recommend that the Agency use a 3 percent discount rate for standard setting, with a sensitivity analysis us ing a 0.5 and 1 percent rate. Th is practice would follow EPA and OMB guidelines for estimating costs or bene fits that affect multiple generations.

Comment : Attorneys General, 2008-0089-0495, Pg. 67-89 Provides a paper by Frank Verboven, “Implicit Intere st Rates in Consumer Durables Purchasing
Decisions – Evidence from Automo biles”, March 1999. The paper examines consumer decisions to purchase 41 pairs of identical cars with the exception being whether they are equipped with diesel or gasoline engines in different European countries. Diesel engine s have a higher initial purchase price but provide future savings in opera ting costs. He infers implicit interest rates given the purchases of gasoline and diesel variants, the differences in initial purchase price, priceI-16

of gasoline and diesel fuel costs per mile and other characteristics. The implicit interest rate that consumers use in making this decision is es timated to range from 5 to 13 percent.

Agency response : Discounting represents the conversion of the economic values of benefits and costs that are expected to occur in the future to their equivalent values to day, or present values.
It is intended to account for the fact that most individuals att ach lower values to economic outcomes that are not expected to occur until some future date th an to equivalent outcomes that are expected to occur sooner. It is particularly important to discount the future values of benefits or costs when they are expected to vary from year to year, or when the ti me profiles of benefits and costs are not expected to be similar. Discou nting enables a consistent comparison of benefits to costs across time periods, and also enables cons istent comparison of costs or benefits that are expected to occur in the future to those that occur in the present.

In establishing the proposed CAFE standards for MYs 2011-2015 that were presented in the NPRM, and whose environmental impacts were ev aluated in the Draft EIS, NHTSA employed a
discount rate of 7% to discount future benefits and costs resul ting from increased fuel economy to their present values. Discounting the value of fu ture fuel savings and othe r benefits that result from higher fuel economy, as well future costs resulting from added driving caused by the fuel economy rebound effect, accounts for the fact that they will occur over the future lifetimes of the
MY 2011-15 vehicles. The discount rate expresses the rate at wh ich the value of these future benefits and costs – as viewed from today’s perspective – declines for each year they are
deferred into the future.

In response to the extensive comments it receiv ed to the NPRM and the DEIS on this issue, NHTSA has carefully reviewed published research and OMB gui dance on appropriate discount rates, including discount rates that should be applied to benefits th at are expected to occur in the distant future and thus be experienced mainly by future generations, and discount rates that buyers of new vehicles apply to savings in fuel costs from higher fuel economy. For purposes of this final rule, the agency has elected to apply se parate discount rates to the benefits resulting
from reduced CO 2 emissions, which are expected to reduc e the rate or intensity of climate change that will occur in the distant future, a nd the economic value of fuel savings and other benefits resulting from lower fuel consumpti on, which will be experienced over the limited lifetimes of newly-purchased vehicles. Speci fically, NHTSA has decide d to discount future benefits from reducing CO 2 emissions using a 3 percent rate, but to discount al l other benefits resulting from higher CAFE standards for MY 2011 cars and light truc ks at 7 percent.

As some commenters pointed out, OMB guidance on discounting pe rmits the use of lower rates to discount benefits that are expected to occur in the distant future, and will thus be experienced by future generations. 20 The main rationale for doing so is that although most individuals demonstrate a strong preference fo r current consumption over consum ption they expect to occur
later within their own lifetimes, it may not be appropriate for society to exercise a similarly strong preference for consumption by current ge nerations over consumption opportunities for future generations, particularly when it is contemplating actions that affect the relative income levels of current and future generations. In a ddition, while market intere st rates provide useful guidance about the rates that should be used to discount future bene fits that will be experienced

20 White House Office of Management and Budget, Circular A-4, September 17, 2003, pp. 35-36.I-17

by current generations, no comparable market rate s are available to guide the choice of rates for discounting benefits that will be r eceived by future generations.

For this final rule, NHTSA has elected to use a ra te of 3 percent to discount the future economic
benefits from reduced emissions of CO 2 that are projected to re sult from decreased fuel production and consumption. These benefits, whic h include reductions in the expected future economic damages caused by increased global temp eratures, a rise in sea levels, and other projected impacts of climate change, are anticipat ed to extend over a period from approximately fifty to two hundred or more years after the im pact of this rule on emissions by MY 2011 cars and light trucks occurs, and will thus be experi enced primarily by generations that are not now living. As indicated previously, studies of the ec onomic cost of GHG emissions select a rate to discount economic damages from in creased emissions. These damage s are typically projected to occur over an extended time span beginning many years after the future date when emissions increase, and the chosen rate is used to discoun t these distant future damages to their present
values as of the date when the increased emissi ons that cause them were assumed to occur.

This procedure yields estimates of the dama ge costs from increased GHG emissions during specific future years, which NHTSA uses to valu e the reductions in emissions that would occur each year over the lifetimes of vehicles affected by higher CAFE standards. For example, higher CAFE standards for MY 2011 cars and light truc ks would reduce GHG emissions each year from 2011 through approximately 2047, and the estimated value of avoiding each ton of emissions rises each year over that span. In turn, the estimated economic values of the reductions in GHG emissions during each of those future years must be discounted to their present values as of today, so that they can be compared with the pr esent values of other benefits from higher CAFE standards, and with vehicle manufacturers’ co sts for meeting higher CAFE standards.

The 3 percent rate is consiste nt with OMB guidance on appropria te discount rates for benefits experienced by future generations, as well as with those used to develop many of the estimates of the economic costs of future climate change that form the basis for NHTSA’s estimate of economic value of reducing CO 2 emissions. 21 Of the 125 peer-reviewed estimates of the social cost of carbon included in Tol’s 2008 survey, wh ich provides the basis for NHTSA’s estimated value of reducing CO 2 emissions, 83 used assumptions that imp ly discount rates of 3 percent or higher.

Moreover, the 3 percent rate is consistent with widely-used estimates in economic analysis of climate change of the appropria te rate of time preference for current versus distant future consumption, expected future growth in real inco mes, and the rate at wh ich the additional utility provided by increased consumption declines as income increases. 22 The Ramsey discounting rule is widely employed in studies of potential economic damages from climate changes in the distant future. The Ramsey rule states that -r = δ + η g, where r is the consumption discount rate,

21 Richard S.J. Tol, The social cost of carbon: trends, outliers, and catastrophes, Economics Discussion Papers , July 23, 2008.

22 EPA notes that “In this inter-generational context, a three percent discount rate is consistent with observed interest rates from long-term intra-generational investments (net of risk premiums) as well as interest rates relevant for monetary estimates of the impacts of climate change that are primarily c onsumption effects.” See U.S. EPA, Technical Support Document on Benefits of Reducing GHG Emissions, June 12, 2008, p. 9.I-18

δ is the pure rate of time preference (or the marginal rate of substitution between current and future consumption under the assumption that th ey are initially equal), g is the expected (percentage) rate of growth in future consumption, and η is the elasticity of the marginal utility of consumption with respect to changes in th e level of consumption itself. Commonly used values of these parameters in climate studies are δ = -1 percent per year, η= −1, and

 g = 2 percent per year, which yield a va lue for r of 3 percent per year. 23

The remaining future benefits and costs anti cipated to result from higher fuel economy are projected to occur within the lifetimes of vehicles affect ed by the CAFE standards for MY 2011, which extend up to a maximum of 35 years from the dates those vehicles that are produced and sold. Because the vehicles originally produced during this model year will gradually be retired from service as they age, and those that remain in service will be driven progressively less, most of these benefits will occur over the peri od from 2011 through approximately 2025. Thus, a conventional or “intra-generati onal” discount rate is appropri ate to use in discounting these benefits and costs to their present value when analyzing the economic impacts of establishing higher CAFE standards. 24

The correct discount rate to appl y to these nearer-ter m benefits and costs depends partly on how costs to vehicle manufacturers for improving fuel economy to comply with higher CAFE standards will ultimately be dist ributed. If manufactur ers are unable to recover their costs for increasing fuel economy in the form of higher sell ing prices for new vehicles, those outlays will displace or alter other produc tive investments that manufacturers could make, and the appropriate discount rate is thei r opportunity cost of capital investment. In contrast, if
manufacturers are able to raise selling prices for new vehicles sufficiently to recover all their costs for improving fuel economy, those costs will ultimately affect private consumption decisions rather than capital i nvestment opportunities. Under this second assumption, economic theory and OMB guidance suggest that a consumption discount ra te, which reflects the time preferences of consumers rather th an those of lenders or investor s, is appropriate for discounting future benefits. Since the time preferences of save rs and investors are probably similar, financial intermediation would be expected to equalize inve stment and consumption di scount rates. In the presence of corporate income taxation, howev er, consumption discount rates are generally thought to be lower than the opportunity cost of investment capital. Finally, if competitive
conditions in the new vehicle market manufact urers and potential buyers’ valuation of higher fuel economy permit manufacturers to recover only part of their costs for meeting higher CAFE standards through higher prices for new vehicles, a rate between an investment discount rate and the lower consumption discount rate may be appr opriate, with the exact rate depending on the distribution of compliance costs between vehicle manufacturers and buyers.

23 See Tol (2008), p. 3.

24 NHTSA acknowledges that using different rates to discount the distant and nearer-term future benefits from higher CFAE standards presents a potential problem of ti me inconsistency, which aris es from the much greater uncertainty that surrounds long-term future rates of growth in investment, economic output, and consumption than is
associated with near-term estimates of these variables. However, the agency believes that this problem is less serious than those that would result from using a single rate to discount benefits that occur over the next 25-35 year sand those that are likely to occu r over a 100-200 year time frame.I-19

OMB estimates that the real befo re-tax rate of return on privat e capital investment in the U.S. economy averages approximately 7 percent per y ear, and generally recommends this figure for use as a real discount rate in cases where the prim ary effect of a regulation is to displace private capital investment. 25 However, this figure represents an economy-wide average estimate of the return on private investment, whic h incorporates no risk premium ot her than that associated with uncertainty about future growth in total econom ic output. As a consequence, it may understate the opportunity cost of capital for corporations facing firm- or ma rket-specific risks on future investment returns. In addition, domestic motor vehicle manufacturers currently have little or no accumulated earnings available to re-invest, and ma y be required to enter private capital markets to finance the investments necessary to allow them to comply with higher CAFE standards. In doing so they are likely to face real interest rates well above the 7 percent opportunity cost of capital estimated by OMB, which may provide a more accurate estimate of the appropriate investment rate for discounting future bene fits resulting from increased fuel economy.

OMB guidance estimates that an appropriate cu rrent value for the cons umer rate of time preference – and thus the discount rate that should be used if the costs of complying with a regulation are borne by consumers – is approximate ly 3 percent. However, this estimate is derived from rates of return demanded by c onsumers on highly liquid investments, and is intended to apply to situations where there is litt le or no risk that consumers will actually realize the future benefits resulting from a proposed re gulation. In the case of CAFE standards, buyers face considerable uncertainty about future fuel pr ices, and thus about the value of fuel savings resulting from higher fuel economy. Uncertainty a bout their future levels of vehicle use and the
actual lifetimes of new vehicles also contribute to buyers’ uncertain ty about the value of future fuel savings that is likely to result from purchasing a vehicl e with higher fuel economy. In addition, buyers’ initial investme nts in higher fuel economy are il liquid, and the extent to which they will be able recover the remaining value of an initial investment in a new vehicle that achieves higher fuel economy in th e used vehicle market is uncerta in. Finally, unlike most of the regulations that OMB Circ ular A-4 is intended to address, mo st (75-80 percent) of the benefits from higher CAFE standards accrue directly to the parties they affect – vehicle buyers – rather than to society at large. Ta ken together, these circumstances may make the use of a riskless consumption discount rate, which is intended for use in discounting the economy-wide effects of a proposed regulation on consumption, inappropria te for discounting the future benefits that result from requiring higher fuel economy.

Empirical studies of the discount rates that new vehicle buyers reveal by trading off the higher purchase prices for more fuel-efficient vehicles ag ainst future savings in fuel costs resulting from higher fuel economy, which capture th e effects of these uncertainties , conclude that buyers apply real discount rates well above the 3 percent ra te recommended by OMB for riskless situations. Dreyfus and Viscusi estimate that, when adjust ed to reflect differences between the current
interest rate environment and ra tes at the time the data for their study were drawn, U.S. buyers apply real discount rates in the range of 12 percent when weighing expected future fuel savings against higher purchase prices. 26 Verboven estimates that Eu ropean buyers’ nominal discount

25 White House Office of Management and Budget, Circular A-4, September 17, 2003, p. 33.

26 See Dreyfus, Mark K. and W. Kip Viscusi. 1995. “Rates of Time Preference and Consumer Valuations of Automobile Safety and Fuel Efficiency.” Journal of Law and Economics. 38: 79 –I-20

rates for fuel savings resulting from buying more fuel-efficient new vehicle models range from 5 to 13 percent, with an averag e estimate of slightly above 10 percent. Verboven’s estimate corresponds to a real disc ount rate of approximately 7 percent when adjusted to reflect current
and recent U.S. inflation rates. 27 These studies may provide more reliable estimates of the appropriate consumption rate for discounting be nefits from higher fuel economy than the 3 percent figure recommended in OMB guidance.

Uncertainty about future developments in the in ternational oil market, the U.S. economy, and the U.S. market for new cars and light trucks make it extremely difficult to anticipate the extent to
which vehicle manufacturers will be able to r ecover costs for comply ing with higher CAFE standards in the form of higher se lling prices for new vehicles. If new vehicle buyers expect fuel prices to remain higher than those used by NHTSA to establish CAFE standards for MY 2011, they may be willing to pay the higher prices necessary for manufacturers to recover their costs for complying with those standards. 28 However, potential buyers w ho expect future fuel prices to be lower than the forecast NHTSA relies upon ar e likely to resist ma nufacturers’ efforts to raise new vehicle prices sufficien tly to recover all of their CAFE compliance costs, since those buyers’ assessment of the value of higher fuel economy will be lowe r than that reflected in the
CAFE standards NHTSA establishes.

From the manufacturer perspectiv e, the current financial conditi on of some car and light truck producers suggests that they are lik ely to find it difficult to absorb the full cost of complying with higher CAFE standards. B ecause CAFE standards apply to all manufacturers, establishing higher standards may provide a ready opportunity fo r all producers to rais e car and light truck prices. However, this opportunity may be restri cted if producers that face very low incremental costs for complying with higher CAFE standards because of higher fuel economy levels in their planned model offerings compete aggressively with others that face significant costs for increasing fuel economy levels in their product pl ans to comply with higher CAFE standards.

After considering the comments received and vari ous arguments about the ultimate incidence of manufacturers’ costs for complying with higher CAFE standards, NHTSA has concluded that the costs for complying with higher MY 2011 CAFE standards are likely to be shared by manufacturers and purchasers of new vehicles, bu t that the exact distribution fraction of these costs between manufacturers and buy ers is extremely difficult to an ticipate. Generally, NHTSA believes that manufacturers are likely to be able to raise prices only to the extent justified by potential buyers’ assessments of th e value of future fuel savings th at will result from higher fuel economy, but the agency recognizes that buyers’ va luations of fuel savings are inherently

98; and the adjustment of discount rates reported in that source discussed in NERA, “Discount Rates for Private Costs,” pp. 4-5, attachment to Alliance of Automobile Manufacturers comment on NPRM, Docket Item NHTSA2008-0089-50.

27 See Verboven, Frank, “Implicit Interest Rates in Consumer Durables Purchasing Decisions – Evidence forAutomobiles,” p. 22, attachment to California Department of Justice, comment on NPRM, Docket Item NHTSA2008-0089-0495.

28 Whether they will be willing to do so, however, depends partly on how the combined value of the economic and
environmental externalities used to determine CAFE standards compares to current fuel taxes. It also depends on whether new vehicle buyers take account of the value of fuel savings resulting from higher fuel economy over the entire expected lifetimes of the vehicles they purchase, or over only some part of that lifetime (such as the period they expect to own new vehicles).I-21

uncertain, and undoubtedly vary widely among indi vidual buyers. As a consequence, price increases for new cars and light tr ucks are likely to allow manufacturers to recoup some fraction of their costs for complying with higher CAFE st andards, while the remainder of those costs are likely to displace other investment opportunities that would otherwise be available to them.

Regardless of the ultimate incidence of costs for complying with higher CAFE standards, however, both manufacturers’ opportunity costs for capital investment and empirical estimates of the discount rates that buyers of new vehicles apply to future fuel savings suggest that a rate in the range of 7 percent is an appropriate rate for discounting the nearer-term benefits from increased fuel economy that will occur over the li fetimes of MY 2011 cars and light trucks. Thus for purposes of establishing the CAFE standards a dopted in this final rule and estimating their economic benefits, NHTSA has continued to employ a 7 percent rate to discount future benefits from higher CAFE standards other than those resulting from reduced CO 2 emissions

. Recognizing the uncertainty surr ounding this assumption, NHTSA has also tested the sensitivity of the level of the optimized CA FE standards and their resulting economic benefits to the use of a 3 percent discount rate for a ll categories of benefits.

NHTSA will consider whether to revise the discount rates used in this analysis when it analyzes the consequences of future CAFE standards. At that time, the agency will consider whether to apply a lower discount rate than 3 percent to the benefits from reducing future emissions of CO 2 and other greenhouse gases, as well as whether to use a rate diffe rent from 7 percent to discount the nearer-term benefits from raising CAFE sta ndards. In making these decisions, the agency will consider guidance on discounting future bene fits – particularly t hose from reducing the threat of climate-related economic damages – issued by OMB, EPA, and other government agencies, and will also consider the discount ra tes used by other federal agencies in similar regulatory proceedings. NHTSA will also consid er recent research on appropriate rates for discounting future benefits from reducing the th reat of climate-related economic damages, as
well as on the discount rate s that buyers of new vehicles appl y to the fuel savings they obtain from purchasing models with higher fuel economy, sin ce such research is particularly relevant to its choice of discount rates. Finally, the agency will consider the financia l situations of vehicle manufacturers and the competitive state of the ne w vehicle market at the time it considers new CAFE standards, as well as their implications fo r the choice of an appropriate discount rate for near-term (or “intra-generational”) economic bene fits that result from higher CAFE standards.

Emissions savings per ton – Value of Carbon

Comment: Air Resources Board, 2008-0089-0173, Pg.3 believes we should use the Phase II European Union Allowances – tradable right to emit one ton of carbon dioxide- market value. They are currently trading at $42 per ton, and th e benchmark contracts have fluctuated between $18 and $42 this year, with Germany Deutsche Bank forecasting EUA prices of $60 for 2008 and EUA prices as high as $100 by 2020

Comment: Prof. Michael Hanemann, 2008-0089-0188 r ecommends that NHTSA use a value of $25 per metric ton of CO2 emissions reduce d, growing at 2.4% annua lly beginning in 2005. Commenter disagrees with NHTSA’s rationale for selecting CO2 damage cost, and argues that
there is no credible evidence to support a lower bound of zero on range of possible damage costs.
Commenter identifies Nordhaus and Boyer’s DICE model as a s ource that NHTSA could insteadI-22

have relied upon for estimates of climate damage s to the U.S. economy, but identifies several key assumptions and parameters that commenter believes cause its estimates of U.S. climate damages to be understated by a factor of two to four. Comment includes a detailed discussion of these key assumptions and parameter values, id entifies why the values employed in the DICE model may be incorrect, and recommends values that he views as more defensible on the basis of recent empirical research.

Comment: Union of Concerned Scientists, 2008-0089- 201.1 states that NHT SA undervalues the cost of global warming and should employ a valu e of at least $45 per metric ton CO2, the value at which CO2 emission permits are currently trading on the European Climate Exchange. The recommended value represents a predicted marg inal cost of achieving the required level of emissions reduction for the EU, and is likely to be a conservative estimate of mitigation benefits.
It is consistent with other recent estimates such as the EP A’s assessment of GHG allowance prices under Lieberman-Warner: $22-40 in 2015 and $28-$51 in 2020.

Comment: American Council for an Energy-E fficient Economy (ACEEE), 2008-0089-211.1 argues that the “NHTSA decision to use Tol’s estimat e of $14 as the upper bound based on the argument that this value includes the worldwide co sts CO2 is flawed and the low estimate of the marginal damage cost of carbon emissions also discounts the high risk as sociated with climate change.” Martin Weitzman says accounting for risk of cata strophe raises marginal damage value further “legislative efforts to implement a carbon regime in which the projected market cost of CO 2 is expected to lie between $20 and $30 – signifi cantly higher than the average damage cost assumed by NHTSA – serves as evidence that the U.S. is now beginning to contemplate the high risk of rising greenhouse gas emissions.”

Comment: Center for Biological Diversity, 200 8-0089-0222.1, Pg. 6-10 states that NHTSA’s
value is too low. NHTSA must consider the hi gh premium associated with achieving dramatic
reductions in CO2 emissions in the near term. The sensitivity analysis must include the range of values in Stern (2007). (Hanse n, 2008) says CO2 will need to be reduced from its current 385 ppm to at most 350 ppm soon to avoid seeding ir reversible catastrophic effects. The Volpe model only calculates the marginal costs and benefits provided to consumers and automakers, not society as a whole. NHTSA doesn’t take in to account the loss of bi odiversity and complex and large-scale ecosystem services. The range of estimates of CO2 $/ton extends much higher than $14; there is no just ification for a value of $0; and si mply splitting the difference between two points is not a defensible methodology. Tol (2005) estimates $95/ton. IPCC estimates at $5-125/ton. The Tol studies date back as much as 18 years, with 25 of them more than 5 years old. IPCC notes that integrated a ssessment models likely underesti mate costs because they do not include significant impacts that have not yet been monetized. IPCC estimates as high as $350/ton. Stern (2002) estimates $25 -30/ton or higher. NHTSA’s lower value of $0 suggests the US might benefit economically by letting other countries bear th e costs of unabated American greenhouse gas emissions. This is unethical a nd unfounded. NHTSA’s para phrasing of Tol that many studies fail to consider potentially bene ficial impact of climate change and don’t adequately account for how future development patterns and adaptations could reduce potential impacts isn’t cited as a finding by Tol and didn ’t contribute to the Tol range of estimates.I-23

Comment: National Automobile Dealers Asso ciation, 2008-0089-223.1, Pg. 8 states that NHTSA should consider incorporating into its anal ysis the $2.97 per metric ton recently paid by the U.S. House of Representatives for carbon offsets. See: http://cao.house.gov/press/cao20080205.shtml

.

Comment: Environmental Defense F und, 2008-0089-0224.1, Pg 1-2 and following EDF recommends that social cost of carbon (SCC) estimates be based on a rigorous metaanalysis
that screens for studies that m eet key quality criteria. In par ticular, included studies should use the same low discount rates (3 percent at maximu m) and should come from recent literature. To the extent possible, the studies should account for a broad range of potential climate impacts and risks of catastrophic impacts from climate cha nge. A risk assessment framework may be more appropriate than a benefit cost anal ysis in light of the inherent unc ertainties in SCC estimates.

Comment: Natural Resources Defense Council, 2008- 0089 225.1 Pg. 2, 27 states that the social cost of carbon used by NHTSA is based on an arbitr ary range of values a nd incorrectly relies on a central estimate of $7 per metric ton of CO2. Unmitigated, costs of dangerous climate change are very likely much higher than estimates in standard literature, and NHTSA must use a reasonable risk premium in its calculati ons. They provide a report entitled The Cost of Climate Change: What We’ll Pay if Global Warming Continues Unchecked . The report was published by NRDC in May 2008. It estimates the potential cost s of climate change for the United States and identifies the most vulnerable regions for specifi c types of climate change effects. The report includes NRDC’s policy recommendations to co mbat climate change, including further increasing fuel economy standards.

Comment: Sierra Club, 2008-0089-0226.1, Pg. 2, 6-8 states that NHTSA’s value is too low and was obtained haphazardly. NHTSA needs to cons ider the costs of adverse impacts of global warming cited by the USDA and NOAA. NHTSA took a low-end carbon study average value and further reduced its validity by cutting it in half. NHT SA’s price barely takes a thumb off the
scale. NHTSA value is far below current estimat es. NHTSA’s decision to average $0 and $14 is flawed. The $14 value is itself an average so cannot be used as the max value. Also the Tol $14
value is in 1995 dollars – the 2005 value would be $19. Tol (2005) ways the max value is in the $55-95 range. NHTSA should not rule out the $95 value. Using $0 as the min is wrong because NHTSA has been chastised by the co urt for doing this in the past and several government reports say the impact of CO2 emissions on the economy is significant. The estimate from (Stern, 2006) is $85. EPA’s recent analysis is that it could be as high as $22- 40. The futures market value in 2011 under the ETS is already up to $45. The cu rrent European Prices for carbon under ETS have been $15-25. The USDA predicts incr easing crop failures, decreased livestock productivity, more forest fires, more drought, st rains on water resources, etc. NOAA predicts more heat waves, more droughts, more intens e hurricanes, more winter storms. Hurricane
Katrina demonstrated that the social and economic costs of extreme weather events can be staggering.

Comment: U.S. Senate, 2008-0089-0454, Pg. 1-4 stated th at NHTSA’s value for SCC is too low.
Also NHTSA should throw out the lower bound estimat e of $0 in determining the value of SCC. NHTSA’s averaging of $0 & $14 is likely to be found arbitrary and cap ricious. NHTSA shouldI-24

use a number higher than $14 for the upper bound in the averaging because the Tol $14 is itself

an average.

Agency response : All of the emissions issues are answer ed together. See Chapter VIII and the preamble to the final rule for our response.

Emissions worldwide versus only U.S. emissions

Comment: Alliance, 2008-0089-0179.1, P9, P34, Att3, S8, states that NHTSA should only account for U.S. CO2 benefits, not globally. NERA uses a 20 percent factor for U.S. versus global. EPCA says when considering maximum feasible, the Secretary of Transportation should
consider the need of the United States to c onserve energy. They ar gue that phrase is an extraterritoriality canon and by la w NHTSA must limit consideration of social costs of carbon to domestic impacts.

Comment: Center for Biological Diversity, 200 8-0089-0222.1, Pg. 7, 11 stated that NHTSA
must take into account the costs of climate ch ange outside the US. NHTSA fails to understand the tremendous threats and challenges posed by gl obal climate change. The air basin for GHG is the global atmosphere. Benefits should be estim ated wherever they are experienced. Not doing so vastly underestimates the true costs of clim ate change. Restricting to the US carries the terrible and arrogant implication that the people of the US believe that people in other countries
should bear the environmental and economic burdens caused by American consumer preferences. Nothing in EPCA, NE PA, or other applicable law allo ws NHTSA to restrict to the US. The impact on the developi ng world is disproportionate.

Comment: National Automobile Dealers Asso ciation, 2008-0089-223.1, Pg 8 stated that NHTSA should only count domestic impacts of reducing the social co sts of motor vehicle CO 2. Air “Pollutants” Criteria pollu tant reduction benefits associ ated with the proposed CAFE standards are overstated as the negative impact of inhibited fleet turnove r was not accounted for. With respect to greenhouse gases, NHTSA should account only for any domestic impacts of reducing the social costs of motor vehicle CO 2 , given that EPCA focuses on U.S. energy security
and all other costs and benefits evaluated with respect to the proposed CAFE standards are domestic only.

Comment: U.S. Senate, 2008-0089-0454, p. 3 stated that NHTSA shouldn’t ignore the
international benefits from GHG reduction. NHTSA’s argument that it should exclude nondomestic benefits for consiste ncy with prior CAFÉ rulemakings is irrelevant because NHTSA has not previously valued SCC. OMB specifically allows for the consid eration of non-domestic benefits. The U.S. is obligated under the 1992 U.N. Framework Convention on Climate Change to consider global impacts. If every nation ignored non-domestic benefits, each would set
emissions standards that are far short of socially optimal. NHTS A’s treatment of SCC would put
the rule at substant ial litigation risk.

Emissions Growth rate in the value of carbon emissions over time

Comment: Center for Biological Diversity, 2008-0089- 0222.1, Pg. 8, states that the growth rate over time is 2-4% per year and cites the IPCC.I-25

Agency response: See Chapter VIII and the preamble to the final rule for our response.

Emission reductions values for Criteria pollutants

(CO, VOC, NOx, fine particulate ma tter (PM), and sulfur dioxide (SO2)

Comment: Mark A. Delucchi, 2008-0089-0025, NHTSA needs to include more externalities. It is not clear what kinds of damages are includ ed in your $/ton estimates (e.g., page 24403). You should include health damages, visibility, cr op damages, materials damages, and naturalecosystem damages. I am fairly sure that the EP A damage estimates do not include all of these. You can find peer-reviewed estimates of damages in most of these categories on my faculty web

page.

Comment: Alliance, 2008-0089-0179.1, Pg. 9 P37, Att 2 P107-108, stated that NHTSA should use published EPA estimates on conventional pollu tants, not ad/hoc EPA/NHTSA estimates. Upstream emissions will not be reduced. NHTSA did not take into account the new source review standards, and otherwise assumed away fede ral and state laws that would have the effect of requiring offsets from the upstr eam refineries that NHTSA attemp ts to claim credit for. The upstream emission factors aren’t realistic. NHTS A needs to consider the fleet-turnover effect. Most criteria pollutants will wo rsen for decades. NHTSA did not consider that consumers will delay purchasing new more fuel efficient vehicles in the curr ent marketplace prior to an expensive new government mandate.

Comment: Ford, 2008-0089-0202.1, Pg. 10 recommended that NHTSA consider using CO2 mitigation cost in their analysis in lieu of em ission damage cost. Although vehicles are often perceived to be the major source of CO2 emissions , in fact, 70 percent of man-made emissions in
the United States come from sources other than transportation. Power generation, home energy use and other industries are just a few. It shoul d also be noted that it would be more cost effective to remove CO2 from the utility sector than the vehicle sector presently. As shown in Chart 4, when it comes to the auto industry, light duty cars and trucks co ntribute only about 20 percent of CO2 emissions in the U.S. And on a gl obal scale, that figure is about 11 percent. No single sector can provide the total so lution. All sectors mu st contribute.

Comment: Center for Biological Diversity, 2008- 0089- 0222.1, Pg. 11, stated that NHTSA must include in its benefits analysis emissions of methane, nitrous oxide, and hydroflourocarbons. They represent large amounts of GHGs. Nitrous oxide emissions are equivalent to 29 million
metric tons of CO2. NHTSA must analyze the impacts of the standard in relation to the emissions scenarios and impacts id entified in Bernstein (2007).

Agency response: In response to Mr. Delucchi’s comment, NHTSA is confident that the damage
cost estimates it used in the NPRM to value re ductions in criteria air pollutants and their chemical precursors include the full ranges of human health impacts known to be associated with exposure to each of these pollutants. Differences between these damage costs and the estimates by OMB cited by commenters reflect the fact th at the estimates provided to NHTSA by EPA apply specifically to emissions by motor vehicles , and include separate costs for emissions from stationary sources such as petr oleum refineries where such differences are appropriate. TheI-26

estimates provided by EPA also reflect more up-to-date knowledge about the human health impacts of exposure to criteria air pollutants and the economic costs associated with those impacts than do the estimates reported by OMB. T hus in the analysis it conducted for this Final Rule, NHTSA has continued to use the damage co st estimates supplied by EPA to determine the economic costs or benefits from changes in emissi ons of criteria air pollu tants that result from higher CAFE standards.

In response to comments provided by NERA on be half of the Alliance, NHTSA acknowledges that it may have overestimated reductions in upst ream emissions of some criteria air pollutants (particularly PM and NOx) resu lting from fuel savings in th e analysis it conducted for the NPRM. NHTSA has taken two steps to remedy this possible overestimation. First, the agency used updated emission factors for vehicles used to tr ansport crude petroleum and refined fuel, including ocean tankers, railroad locomotives, barges, and heavy- duty trucks supplied by EPA to
recalculate the emissions factor s for each stage of fuel producti on and distribution in Argonne’s GREET model. These updated emission factors re flect the effects of recent and pending EPA regulations on vehicle emissions and fuel compositi on, and result in signifi cant reductions in the upstream emission rates for fuel production and distribution estimated using GREET. These lower upstream emission rates reduce NHTSA’s es timates of emissions during fuel production
and distribution under both Baseli ne and alternative CAFE standa rds, and by doing so also lower the reductions in upstream emissi ons projected to result from any increase in CAFE standards
from their Baseline levels.

In addition, NHTSA notes that the estimates of reductions in upstream emissions it reported in the NPRM incorrectly included re ductions in ocean tanker emissi ons for transportation of crude petroleum from overseas to ports or offshore oil terminals in the U.S. Since most of these emissions probably occur outside of the U.S., they should not be included in NHTSA’s estimates of upstream emissions reductions, since thos e are intended to represent changes in domestic emissions of criteria air pollutants. 29 NHTSA has revised its analys is for this Final Rule to
exclude reductions in ocean tanker emissions.

In response to comments by Sierra Research and NERA submitted by the Alliance, NHTSA notes that there are currently two cap-and-tr ade programs governing emissions of criteria pollutants by large stationary sources. The Acid Rain Program seeks to limit NOx and SO 2 emissions, but applies only to electric generating facilities. 30 The NOx Budget Trading Program is also primarily intended to reduce electric ut ility emissions, but does include some other large
industrial sources such as refine ries; however, as of 2003, refineries participating in the program
accounted for less than 5% of total NOx emissions by U.S. refineries. 31 In addition, some

29 Emissions from ocean tankers while in port areas, as well as pipeline or truck emissions occurring during transportation of crude petroleum from import terminals to U. S. refineries, do occur within the U.S., and reductions in these emissions should be included when estimating changes in domestic emissions. However, it is not possible to separate these emissions from those that occur in foreign ports or on the open oceans, so NHTSA’s analysis does not include reductions in them. As a consequence, the analysis may underestimate reductions in upstream emissions occurring within the U.S.

30 For a detailed description of the Acid Rain program . see http://www.epa.gov/airmarkt/progsregs/arp/basic.html#princips (last accessed October 6, 2008).

31 Estimated from EPA, NOx Budget Trading Progra m (SIP Call) 2003 Progre ss Report, Appendix A,I-27

refineries could be included among the sources of NOx emissions that will be controlled under EPA’s Clean Air Interstate Rule, which is sc heduled to take eff ect beginning in 2009. However, refinery NOx emissions could only be affected in states that specifically elect to include sources other than electric generating faci lities in their plans to comp ly with the rule, and EPA has indicated that it expects states to achieve the emissions reductions required by the Clean Air Interstate Rule primarily from the electric power industry. 32 Thus the agency continues to assume that the reduction in domestic gasoline refining estimated to re sult from the adopted
CAFE standard will be reflected in reduced refinery emissions of criteria pollutants.

NHTSA also notes in response to comments by Sierra Research and NERA submitted by the Alliance that emissions occurring during refueling at retail stations are included in the emissions factors estimated using EPA’s MOBILE emissi on factor model, which also accounts for expected future reductions in these emissi ons. Thus NHTSA believes that reductions in refueling emissions were correc tly estimated in its NPRM anal ysis, and has not revised its procedures for doing so.

Finally, in response to comments by the Alli ance and NERA, NHTSA acknowledges that the effect of higher prices for new vehicles on the re tention and use of older vehicles is potentially significant, depending on the magnitude of e xpected price increases. Based on detailed econometric analysis of the effects of new vehicl e prices and other variab les on retirement rates for used vehicles very similar to the analys is conducted by NERA for the Alliance, NHTSA concludes that price increases fo r 2011 cars and light trucks likely to result from higher CAFE standards are unlikely to cause significant or lasting changes in retirement rates for older
vehicles. NHTSA also notes that the vehicles w hose retirement rates would be most affected by increases in prices for model year 2011 passenger cars and light trucks are those that will be 10- 15 years of age at the time when 20 11 vehicles are offered for sale. 33 These include cars and light trucks produced during model years 1996 through 2005, and NHTSA’s analysis of their emission rates at those ages predicted using EPA’s MOBILE6.2 motor vehicle emission factor model suggests that they will not be dramatically higher than em ission rates for comparable new
2011 models. Thus the effect on total motor vehicl e emissions of criteria air pollutants resulting from any reduction in new vehicle sales and acc ompanying increase in use of older vehicles caused by increased prices for new 2011 cars and light trucks is likel y to be modest.

Externalities - Monopsony effect

Comment: Mark A. Delucchi, 2008-0089-0025, recommends use global warming damages in the U.S. only. Your discussion on p. 24414 is correct: if you include Paul Leiby's estimate of the

http://www.epa.gov/airmarkets/cmprpt/nox03/NBP 2003AppendixA.xls, and National Air Quality and Emissions Trends Report 2003, Table A-4, http:// www.epa.gov/air/airtrends/ aqtrnd03/pdfs/a4.pdf

32 The Clean Air Interstate Rule also requires reductions in SO2 emissions and establishes an emissions trading program to achieve them, but only electric generating facilities are included in the rule’s SO2 emissions trading program; see EPA, Clean Air Interstate Rule: Basic Information, http://www.epa.gov/cair/basic.html#timeline (last accessed October 6, 2008) and http://www.epa.gov/cair/pdfs/cair_final_fact.pdf (last accessed October 6, 2008).

33 This conclusion is based on detailed econometric analysis of the effects of new vehicle prices and other variables on retirement rates for used vehicles conducted by the Volpe Center. This analysis concluded that retirement rates for 10-15 year old vehicles are most sensitive to changes in new vehicle prices.I-28

monopsony cost (e.g., p. 24411) -- which in a global accounting is a transfer and not a resource cost -- on the grounds that your c ounting costs and benefits to th e U. S. only, then consistency requires that you count global warming damages in the U. S. only. It is possibl e to estimate U. S. damages only: I have done it in the followi ng report, available on my faculty web page: Summary of the Nonmonetary Externalities of Motor-Vehicle Use. Delucchi, Mark A. ITSDavis. Report #9 in the series: The Annualized So cial Cost of Motor-Veh icle Use in the United States, Based on 1990-1991 Data. October 2004. P ublication No. UCD-ITS-RR-96-3 (9) rev. 1. Revision of report originally published in September 1998.

Agency response: We concur with this comment and include monopsony when counting global warming damages in the U.S. only. See Chapter VIII for more discussion on monopsony.

Externalities - Supply disruption costs

Comment: Union of Concerned Scientists, 2008- 0089-0201.13, Pg. 24, 31 stated that NHTSA’s
value is too low. ORNL assesses the benefits of reduced oil consumption for reducing supply disruption and market price spikes at $14.51 per barrel. This is a conservative assessment as it excludes all military costs and the forei gn policy impact of oil import reliance.

Agency response: We use the same data source, ORNL, but find a much smaller value. See Chapter VIII for more discussi on on supply disruption costs.

Externalities - Military costs

Comment: Air Resources Board, 2008-0089-0173.14, appear s to recommend that reductions in military outlays equivalent to $0.03-0.15 per gallon of fuel saved be included as benefit from fuel savings attributable to higher CAFE standards. Comment c onsists of recent article authored by Mark Delucchi and James Murphy, published in journal Energy Policy (citation: Energy Policy 36 (2008) 2253– 2264). Article attempts to esti mate total U.S. military outlays that are directly attributable to securing flow of oil imports to the U.S. from the Persian Gulf region, and
the fraction of these that are attributable to m eeting U.S. demand for motor vehicle fuel. Authors conclude that these amount to $15 billion a nnually, or $0.03-0.15 per gallon of fuel consumed by
U.S. motor vehicles.

Comment: Mark A. Delucchi, 2008-0089-0025 stated that m ilitary costs should not be zero (p. 24411). I have just published a peer-reviewed articl e in Energy Policy that can serve as one basis for making a non-zero estimate of the cost.

Comment: Public Citizen, 2008-0089-0187, Pg. 4 o bjects to the zero valu ation of military security costs associat ed with oil consumption. NHTSA states “that while costs for U.S. military security may vary over time in response to l ong-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.” 23 NHTSA justifies this claim by stating that ther e are other national security and foreign policy objectives served by military action s in the Middle East. NHTSA u sed similar logic to justify assigning zero value to reducing CO2 emissions in the light truck rule. The Ninth Circuit Court ofI-29

Appeals rejected this justification in Centerfor Biological Diversity v. NHTSA , finding that uncertainty about how to assign a value was not a justificati on for setting the value at zero. 24

Comment: Attorney General of th e States, 2008-0089-0199.1, Pg. 11. It is true that an increase in CAFE standards will not, in and of itself, elim inate these energy security costs. The same could be said as to global warming cost s. It is also the case, however, that the impact of higher CAFE standards on energy security is not zero. Energy security costs are a necessary piece of the puzzle in assessing all of the costs and benefits of a CA FE standard. In fact, a recent peer-reviewed economic analysis did assign values to the mil itary savings attributable to decreased oil imports. See Mark A. DeLucchi & James J. Murphy, US Miliary Expenditures to Protect the Use of Persian Gulf Oil Imports, 36 Energy Policy 2253 (2008) (assigning a cost of between $0.03 and $0.15 per gallon, and referenc ing earlier work on this issue).

Comment: Consumer Federation of America, 2008-0089-0183, Pg, 47-48, 61-62 stated that a zero value is simply wrong. NHTSA should use 30 cents/gallon. The fact that the statute had energy independence and security in its title sh ould have alerted NHTSA to the likelihood that Congress considers the military and st rategic value of oil important.

Comment: Natural Resources Defense Council, 2008-0089 225.1, Pg. 2 and following, the economic value of military security to protect oil supplies should be non-zero and positive. When NHTSA used zero it ignored the U.S. military security-related benefits of reduced oil consumption, such as enhanced flexibility to re spond to supply threats and move the country in the direction of oil being a nonstrategic resour ce. The report also s uggests that NHTSA should
include the benefits from lower oil use that woul d result from the subseque nt marginal decline in the need for military resources protecting a strategic commodity (oil).

Comment: Sierra Club, 2008-0089-0226.1, Pg. 2, 7 stated that NHTSA must recognize the national security costs of oil. The military-rela ted expenses are tremendous. See the 2005 report of the International Center for Technology A ssessment. NHTSA’s decision to ignore military costs is arbitrary and capricious.

Agency response: The Deluchi estimates are clearly identifi ed as savings that would result if demand for petroleum-based fuels by U.S. motor vehicles were completely eliminated. The
article includes little or no discussion of the extent to which military outlays would vary in response to marginal reductions in U.S. fuel cons umption of the scale likely to result from higher
AFE standards or other fuel conservation measur es, indicating only that any reduction in U.S. military outlays would result from policy decisions to be made by Congress. The agency believes at this time that military outlays would not vary depending upon the fuel economy standards and uses $0.00 in the main analysis, with a sensitivity analysis examining the impact of $0.05 per gallon for military outlays.

While NHTSA believes that military expenditure s appropriated by the U.S. Congress are not directly related to changes in domestic petr oleum consumption, the agency recognizes that reductions in petroleum consumption may provide other benefits that are more difficult to quantify, by reducing some constraints on U.S. di plomatic and military action. U.S. foreign policy decisions consider a wide range of U.S. interests, including the maintenance of secure petroleum supplies. Reduced consumption of petroleum might allow the U.S. to moreI-30

vigorously pursue other foreign po licy interests, by reducing concer ns about the implications of pursuing these other interests fo r the availability and continui ty of petroleum imports.

The agency recognizes, however, th at both the effect of reducing U.S. petroleum imports on the flexibility of its foreign policy initiatives and the economic value of such additional flexibility are highly uncertain. Reducing pe troleum consumption is likely to have unpredictable effects on both military actions and diplomatic initiatives, and even if the U.S. government planned and signaled its foreign policy intenti ons under various levels of petr oleum consumption in advance, NHTSA is unaware of any accepted methods for establishing the economic value of increased freedom in designing military or diplomatic ac tions. And because the nation’s foreign policy intentions are not communicated in advance, the agency would need to develop a procedure for anticipating how military and diplomatic actions would respond to future changes in petroleum consumption. Nevertheless, in its future rule making activities, NHTSA will investigate whether practical methods for predicting a nd valuing in economic terms any increased flexibility in U.S. foreign policy that is likely to result from reduced petroleum im ports exist or can be developed.

Financial Impacts of Raising CAFE Standards a nd ability of manufacturers to finance fuel economy improvements

In the PRIA, the agency admitted that the agen cy does not have the capability to predict the capital investment needs of the automobile indus try to install fuel economy technologies, nor the capability to determine the level of capital invest ments available to specific manufacturers in the future. We asked several questions regarding the manufacturers’ financial capabilities in meeting the proposal and the alternatives examined. Specifically we asked:

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

Please discuss whether you anticipate that your firm will to be able to raise the incremental capital investments necessary to m eet the levels predicted in answer to the questions above. If the answer is no, what le vel appears likely to be achievable. What
alternatives are available to raise the incremental capital investments necessary?

Essentially, the agency received no comments about the companies’ abilities to raise capital or finance the capital investments necessary to meet alternative levels of th e standard. Instead, it received comments that the proposal wasn’t feasible or that the standard are inconsistent with those in the European Union or Japan, or that they are currently losing money.

Comment: General Motors, 2008-0089-0162, Pg. 9, st ated that NHTSA assumes that
manufacturers either have the capital or the ab ility to borrow funds to meet the proposed standards. That assumption i gnores the reality facing GM. N one of the supporting studies, nor NHTSA’s modeling process, quantita tively address the real world constraints that exist in terms
of technical and financial resources . The roll-out rate may substa ntially exceed the capability of GM to actually implement. If the future standards cannot be achieved by technology, then compliance can only be achieved by product eliminat ions, plant closings and job losses. TheyI-31

provide in Attachment 6 a section from GM’s 10-K statement, that is a general statement indicating that sales levels in th e industry are projected to declin e in 2008. They have relatively high fixed costs and high unit contribution margins, such that small chan ges in the number of vehicles sold can materially adversely affect their operation and financ ial conditions.

Agency response: GM does not specifically address their potential to finance technology improvements and NHTSA does not have the wherew ithal to know how to determine what level of capital financing will be avai lable to GM in the future.

Comment: The Alliance, 2008-0089-0179.1, Pg. 8, 20, 21, state that NHTSA should account for the industry’s capital constraints. NHTSA r ecognized capital constraints in the 2008-2011 light truck rulemaking. Why has NHTSA ch anged course on that issue?

Rod Lache of Deutsche Bank stated “we do not expect automakers to be able to pass all of these costs along to consumers”. Quote “an agency is arbitrary and caprici ous if the agency ... entirely failed to consider an important aspect of the problem, offered an explanation for its
decision that runs counter to the evidence before the agency ... entirely failed to consider an important aspect of the problem, offered an explan ation for its decision that runs counter to the evidence before the agency, or is so implausible th at it could not be ascr ibed to a difference in view of the product of agency expertise.”

Agency response : The agency did not take into account capital constraints in the 2008-2011 light truck rulemaking. The agency recognizes that vehicle manufacturers must have sufficient lead time to incorporate changes and new features in to their vehicles. In making its lead time determinations, the agency considered the fact that vehicle manufacturers follow design cycles when introducing or significantly modifying a product. We have a pplied the same rationale here. If the market (or regulation) drives manufacturers to make changes, they must do so to sell their vehicles. The Alliance provides no estimate of their own on how to account for capital
constraints.

Comment: Mitsubishi, 2008-0089-0197.1, Pg. 1, 5-6 stated that the NPRM requires extremely expensive and complex adjustment s to product plans to meet very strict standards for cars and trucks in MY 2011. MMC would likely suffer seve re financial difficulties. The NPRM has not considered capital constraints. MMC requests NHT SA consider capital constraints in the final rule. The product development cycle is al ready underway for MY 2011. Retail prices for MMC’s compact vehicles, which comprise the major ity of our overall sales in the US market, are expected to double as a result of the standa rd. In FY 2007, MMC had an operating income deficit of $178M. In 2008, MMC forecasts net sa les in North America will drop by 25.5% and that ordinary income in the US will further decl ine by an additional $92M. We are still in the process of recovery after our alliance with DAG dissolved in 2004. MMC has limited access to additional capital for investments in new technologies.

Agency response: Mitsubishi provides no estimate of their own on how to account for capital
constraints.

See Chapter VII for our general disc ussion of financial impacts.I-32

Inequality of impacts on smaller manufacturers

Comment: BMW, 2008-0089-0146.2, Pg. 2 and 0146.3 Pg. 1 stat ed that the standard is costly to small manufacturers. Niche manufacturers (such as BMW whose vehicles offer extraordinary safety, comfort, and convenience features, and so have a high mass per footprint density) have to fulfill more ambitious requirements. BMW requests an option of not using the footprint, but a standard increase per year.

Comment: Fuji (Subaru), 2008-0089-0157, Pg. 2-4, 6-8 stat ed that the standards aren’t fair to small manufacturers. The passenge r car standard requires virtually nothing of the high volume manufacturers but requires large fuel economy increases among small manufacturers. Small
manufacturers don’t have the same capability to offset targets for smaller footprint vehicles with larger vehicles. Subaru proposes small manufacturer s be provided an option to pay civil penalties based on their target fuel economy, instead of meeting the target.

Comment: Ferrari, 2008-0089-0168, Pg. 3-5 stated that NHTSA’s assertion that its proposal will not have a significant economic impact on sma ll businesses is wrong. NHTSA does not always grant petitions from small manufact urers for alternative standards. Ferrari’s fines will increase significantly. Also the standards aren’t fair to niche manufact urers, specializing in higher performance sport vehicles. The same set of ga s guzzler vehicles can be penalized or not under the standard, depending on whether they are made by a small manufacturer or a large one (who
can offset these with other vehicles exceedi ng the standard). This is discrimination.

Comment: Porsche, 2008-0089-0174.1, Pg. 12-13 stated that the standards result in inequities for smaller limited line manufacturers. The footprint-only attribute assigns to smaller limited line manufacturers targets that are beyond the reach of their vehicle fleets. The only choices for these manufacturers are to leave the market, restrict product or pay exorbitant civil penalties. The car standard requires virtually no improvement by the larger full line manufacturers during the early years. The standards were set using only the 7 largest ma nufacturers. From MY 2007 to MY 2011 Porsche is required to increase its pass enger car fleet an average of nearly 10% per year, over twice the predicte d annual industry average.

Comment: Volkswagen, 2008-0089-0181, Pg. 3 commented that an alternative attribute in addition to footprint should be used to equalize cost burden on all manu facturers. Volkswagen argued that the footprint attribut e alone when applied to the passen ger car fleet creates challenges for some automakers with limited product range and/or limited market segments. For some automakers it appears that their products or fleet mix demonstrate unfavorable correlation to the footprint curves as generated by NHTSA and result in additional burden for those auto makers. NHTSA should consider alternative compliance approaches to alleviate the st ringency applied to limited product line producers. An example of this is the uniform increase concept.

Comment: Mercedes, 2008-0089-0190, Pg. 3-4 stated that the requirements on manufacturers excluded when setting the standa rd are disproportionate to t hose imposed on larger full line
manufacturers. The standard re quires virtually no improvement by the 7 largest manufacturers.I-33

The targets require colossal investment by the ex cluded manufacturers to modify their fleets. Even then, these companies many still be subject to severe civil penalties. Mercedes would need to improve its fleet in MY 2011 by 28% over MY 2007.

Comment: Mitsubishi, 2008-008900197.1, Pg. 2, 5 stated that the standard puts manufacturers with smaller average footprints at a competitive disadvantage. The targets were set using manufacturers that have larger average footprints. These manufacturers face disproportionately burdensome requirement in the early years. It is more difficult for these manufacturers to negotiate supplier contra cts to purchase new components. Large suppliers can negotiate more cost effective supplier contracts and in some instances co-develop or internally develop new components before the market creates an economy of scale. Small and midsize companies are also at a disadvantage in term s of when new components are r eceived from suppliers. The supply of new components is limited due to su pplier capacity and output. The sizable demand for new components from larger manufact ures is fulfilled first by suppliers.

Comment: Ford, 2008-0089-0202.1, Pg. 3 stated the agency should revise the proposal to ensure that all manufacturers have a comparable burden, or at least ensure that whatever differences may exist will not hinder any manufacturer's ability to compete in the marketplace. Given the
manner which NHTSA has chosen to draw the ca r and truck curves, some manufacturers have tasks to improve their fuel economy every model y ear, while others do not. In particular, the proposal gives domestic full-line manufacturers significant tasks relative to their competitors. This is not inevitable; it is a reflection of the particular shapes that NHTSA has chosen for the

curves.

Comment: Association of Intern ational Automobile Manuf acturers (AIAM), 2008-0089-205.1, Pg. 3 stated that the abrupt increase in fuel ec onomy required in the earl y years is particularly severe for smaller companies. Smaller companies face required increases in fuel economy of 17- 88% from 2007 to 2011. Smaller companies tend to have fewer resources to implement major changes on an expedited basis. These companies te nd to produce vehicles that fall in the steep central portion of the car curve. They have a limited range of product offerings, so have fewer options for achieving required fu el economy increases. Redesign cycles may not coincide with
the 2011 start date.

Agency response: For the final rule the agency is includi ng all manufacturers (not just the largest seven producers) in determining the CAFE require ments. We will have one standard that is applicable to all medium to la rge size passenger car manufacturers (very small companies – less than 10,000 sales worldwide - can petition for altern ative standards). While the current form of the standard may cause difficulty for some manufact urers, the standard is designed more to deal with the overall industry than with particular, niche vehicle makers.

For purposes of this rulemaking, the agency is no t interested in providing an alternative flat standard that includes a set ye ar-by-year increase in the CAFE levels. The current CAFE structure is designed to be at tribute-based per legislative mandate. We also have the simultaneous objectives of improving industr y-wide fuel savings, GHG emissions, and preserving safety. NHTSA has an attribute-based approach whic h provides no incentive to build smaller cars just to meet a fleet-wide average, be cause smaller vehicles will be subject to moreI-34

stringent fuel economy standards. The approach is to determine what level of fuel economy can be achieved primarily by new technology.

Leadtime issues

Comments: With the exception of Borg Warner, 2008-0089-0142 Page 1, that stated that leadtime and levels are very aggressive but possible, the remainder of the commenters on leadtime stated that the proposed requirements in the early years were too aggressive or beyond the maximum feasible level for their company. Included in this group were: Fuji (Subaru), 2008-0089-0157, Pg. 2, 5, 7-8 General Motors, 2008-0089-0162, Pg. 2, The Alliance, 2008-0089-0179.1, Pg. 23 Mercedes Benz, 2008-0089-0190.1, Pg. 3 Mitsubishi, 2008-0089-0197.1, Pg. 1-2 AIAM, 2008-0089-0205.1,Pg. 3-5 Toyota, 2008-0089-212, Pg. 2 wants a 3.3% improvement per year, not 4.5%. Mercatus Center, 2008-0089-216.1
National Automobile Dealers A ssociation (NADA), 2008-0089-223.1, Pg. 2 Washington Legal Foundation, 2008-0089 228, Pg. 3,5

Agency response: The costs for technologies and effectiven ess and the leadtime issues were all
addressed in consultation with our contractor. The model y ear 2011 requirements are not as aggressive in the final rule as proposed in the NPRM.

Learning curve In the PRIA for some of the technologies, we included a learning factor. The “learning curve” describes the reduction in unit production cost s as a function of accumulated production volume and small redesigns that reduce costs.

Comment: Borg Warner, 2008-0089-0142, Pg. 1, stated that the learning curve assumptions aren’t correct. Learning curve do not apply to many of their products. Th e technologies are well developed and in high volumes in other parts of the world, so our price/cost estimates already represent higher volumes. In f act, increasing global volumes c ould lead to higher prices if demand for certain raw materials exceeds supply.

Comment: The Alliance, 2008-0089-0179.1, Pg. 6-7 believes the learning curve assumptions are not supported. Martec’s updated 200 8 analysis explains that its corrected and or iginal study both fully accounted for learning effects.

Comment: AIAM, 2008-0089-0205.1-Pg. 5 stated that some of NHTSA’s cost estimates may reflect double counting of the cost learning curv e effect. The learning curve estimates in the 2002 NAS study and the EEA and Martec reports al ready reflect to some degree learning curve
considerations.

Comment: Public Citizen, 2008-0089-0187,Pg. 7 The agency has included “learning curves” to attempt to model the reducti ons in cost of compliance due to economy of scale effects.
Public Citizen observes that eco nomy of scale effects should be accounted for; however, weI-35

wish to point out that again these effects are often estimated incorrectly. In a survey of emission reduction regulations, the author finds: “In all cases except one, the early estimates [of cost of compliance] were at leas t double the later ones, and often much greater.” Inaction based on
inflated estimates of cost of compliance ca nnot be tolerated in the face of an energy crisis and environmental catastrophe.

Comment: Honda, 2008-0089-0191, Pg 6 stated that l earning curve costs sh ould be raised in early years and decreased in later years. The cost estimates provided to NHTSA through NAS, Energy and Environmental Analysis Inc (EEA), and the Martec Group all assume high volume production and th orough product development. Thus, these costs alre ady include substantial amounts of learning. Proper applic ation of learning factors woul d increase costs for early, low volume production of these technologie s, to reflect that they have not yet ac hieved the learning and cost reductions assumed by NAS, EEA, and Martec. Once sales exc eed about 300,000 per year per manufacturer, the learni ng factors could begin to d ecrease the cost estimates from NAS, EEA, and NHTSA. But the learning factors mu st be applied consistently to both raise costs in the early years and decrease them in later years, not just reduce costs.

Agency response: For the final rule, t he learning curve assumptions were all reviewed in
consultation with our contractor(Ricardo). The lear ning curve assumptions have been changed and are addressed in Chapter V.

Marginal cost = Marginal benefit (MC=MB) versus total cost = total benefit (TC=TB) approach in setting final rule

In the NPRM, the agency provi ded alternatives which included both MC=MB and TC=TB. However, the proposal was based on MC=MB.

Comment: The Alliance 2008-0089-0179.1, Att3, P-7 commended NHTSA for using MC=MB, rather than TC=TB stating that TC=TB costs $12.5 billion more, but only yields $7 billion in
benefits.

Comment: Attorney General of the States, 2008-0089-0199.1, Pg. 9 st ated that the standard
should m aximize energy conservation instead of ne t economic benefits. Congress has already made the judgment that energy conservation is the highest priority among the factors for NHTSA
to balance. Center for Biological Diversity , 508 F.3d at 527-28 (discussing Center for Auto Safety v. NHTSA , 793 F.2d 1322 (D.C. Cir. 1986)). To achieve this goal, NHTSA should set the
standards at a level where the to tal costs equal total benefits. 2 From a societal point of view,
there cannot be substantial adve rse consequences if the costs do not outweigh the benefits. We urge NHTSA to set the standard at a leve l where total costs equal total benefits.

Comment : Union of Concerned Scientists, 2008-0089-201.1 and 2008-0089-0201.13 Pg. 3-4, 25-30 recommends against the use of a marginal cost-marginal benefit analysis, and believes
NHTSA should instead use a total cost-total benef it analysis to determine maximum feasible fuel economy standards. The use of a TC=TB analysis would maximize the need to conserve energy while ensuring consumers are as “well off” as th ey are today. An analysis of the recommended form would reduce the impact of any inaccurate monetizing of the benefits of reduced fuel consumption, and would increase the economically practicable fleet av erage between 2.8 and 5.7I-36

miles per gallon. MC=MB is very sensitive to diffe rent valuations of benefits, making it more error prone. An MC=MB analysis that excludes or undervalues even some of the benefits is fundamentally flawed.

Agency response: For purposes of this rulemaking, NHT SA has concluded that the maximum feasible standards are represen ted by the level at which net benefits are maximized. NHTSA recognizes that the overarching purpose of EP CA is energy conservation, and considers the need to conserve energy as part of its balancing of the four statutory factors. However, NHTSA disagrees with the Attorneys General that ther e would be no substantial adverse consequences for purposes of this rulemaking from setting the standards at the level represented by TC = TB. Based on NHTSA’s analysis and given the uniqu e circumstances surrounding this rulemaking, including the economic crisis and the conc urrent burden on manufacturers, NHTSA has concluded that TC = TB would be beyond the maximum feasible level at which the MY 2011 standards could be set. However, the agency wi ll reconsider in future rulemakings whether to
set standards at the level of TC = TB.

Market Failure

Executive Order 12866 requires that all new federal regulations specify the market failure that will be addressed by the rulemaking. The agency state that the Energy Policy and Conservation Act (EPCA) directs the Department to balance th e technological and economic challenges related to fuel economy with the nation's need to cons erve energy. Congress de cided that the market would not balance these challenges in the best in terest of the nation, and that the Department should regulate fuel economy.

Comment: The Consumer Federation of America, 2008-0089-0183 -pp. 37-40 stated that NHTSA’s view of market failure is very narrow, generally admitting only a problem of externalities that are not internalized. We susp ect there are other sources of market failure, like information problems, agency problems, perverse incentives, etc. Moreover the problem is not
limited to the demand side of the market. Ther e are imperfections in the supply side. NHTSA discovers that there are fuel savings technologies that pay for themselves, but have not been
moved into the vehicle fleet. Since this cannot be explained by externalities market failure, there must be other market failures operating.

NHTSA’s pro industry view of the world blames the market failure on the consumer, when in fact the problem is the automakers.

Agency response: NHTSA didn’t present a view of the world, just a statement that Congress requires it to set fuel economy standards.

Comment: The Mercatus Center, 2008-0089-216.1 questio ns whether there is failure in the “market” for fuel economy that needs to be re gulated. To support this assertion they present evidence of recent market forces (e.g. rising fuel costs) driving fuel economy standards above current CAFE standards. They also suggest th at drivers are becoming more willing to demand and pay for fuel economy due to heightened aw areness of environmental externalities (CO2 emissions).I-37

Agency response: We see no need to debate the needs for regulation, since Congress requires us to set fuel economy standards.

On-road fuel economy adjustment – 20 percent

In the NPRM, the agency reduced the EPA test data by 20 percent to account for on-road fuel economy in determining the benefits of the proposal.

Comment: There were two comments on this is sue (Sierra Research 2008-0089-0046, Page 76,
and Air Resource Board 2008-0089-0173.11, p10). Sier ra Research employed a different adjustment factor, adjusting the EPA dynamomete r test results downward by 10% for the city cycle and 22% for the highway cycle to better re flect real world driving (18% reduction used for a hybrid). The Air Resource Board presented a study “Analysis of In-Use Fuel Economy Shortfall Based on Voluntarily Reported MPG Estimates”, by Greene et al., Nov. 2005.

Agency response: The agency will rely on the published EPA final rule guidelines and continue using 20 percent. The report by Greene et al . was completed prior to EPA’s changes to its labeling regulations. Neither commenter suggest ed that NHTSA use these numbers instead of EPA’s for analyzing fuel savings.

Payback Period

In the PRIA, we assume in the sales impact analys is section that consumers will only value fuel savings over a 5 year time horizon.

Comment: Mark A. Delucchi, 2008-0089-0025, states that you should not do a "payback" analysis with a zero discount rate and a 5-ye ar payback period, because there is no economic theory or consumer behavior al evidence to support this.

Agency response: Commenter provides no alternative, other than using a full lifetime payback period. NHTSA disagrees that cons umers think in that long term.

Comment: Sierra Research, 2008-0089-0046, Pg. 77, consid ers 5 years and 20 years, but say that average consumers are more likely to consider the time they own the car to be 5 years.

Comment: Consumer Federation of America, 20 08-0089-0183, Pg. 53-59 state that a simple payback is one of the weaker economic concepts fo r evaluating investment. It is not clear that one must assume a payback for any component of a vehicle purchase, but if one does, the logical connection is between the period of owners hip and the payback, not the loan period.

Most alternative investment oppor tunities available to consumer s do not yield a 5 year payback period. Hybrids, many of which have payback peri ods of ten year or more, are flying off auto dealer lots. There is a logical inconsistency in saying that cons umer decisions to buy vehicles
reflects undiscounted treatment of fuel savings, but auto industry sales reflect discounted fuel savings.I-38

Agency response: We don’t have an inconsistency in our analysis, the consumer decision is in the same section where we estimate the impact on auto industry sales. When we do our MC=MB analysis it is from a societal perspective and full lifetime benefits are calculated.

Comment: Union of Concerned Scientists (UCS ), 2008-0089-201.1 states that NHTSA should modify its resale value estimate. UCS asserts that the agency’s cost-benefit analysis ignores the
fact that fuel efficient vehicles have higher resale values than inefficient vehicles. UCS asserts that NHTSA’s assumed 5-year resale evalua tion timeline is unfounded. Also, citing a CBO study, commenter asserts that the assumption of a fixe d resale value rate ignor es the fact that fuel
efficient vehicles are valued more highly on the used vehicle market

Agency response: Assuming that more fuel efficient vehi cles have a higher resale value would be inconsistent with our assumption that cons umers only think 5 years into the future for a payback period. Essentially we would be assuming th at if a vehicle is sold in 5 years, consumers
think about the fuel that would be saved in years 6 to 10, and how th e next purchasers would
value that and how that would aff ect the resale value. But if c onsumers keep their vehicle, and don’t sell it, they don’ t think about the fuel savi ngs in years 6 to 10.

Comment: National Automobile Dealers Association (NADA), 2008-0089-223.1, Pg. 7

The proposal reasonably assumes that buyers value any fuel savings associ ated with the purchase of a new motor vehicle over a five-year period, rath er than over a vehicle’ s full useful life. Even at high fuel prices, consumers w ho view fuel economy as an impor tant purchase criteria are hard pressed to make the case for buying a more fuel e fficient new vehicle if th e up-front capital costs associated with doing so cannot be recouped in short order. Th us, NHTSA should assume that most prospective purchasers will not invest in fuel economy improvements that do not exhibit a payback of five years or sooner. Of course, for purposes of calculating payback, real-world purchaser finance costs, opportunity costs, a nd additional maintenance costs all should be
accounted for.

Agency response: NADA essentially agrees with out methodology.

Price of Gasoline

Projected future fuel prices are a critical input into the regulatory impact analysis of alternative CAFE standards, because they determine the va lue of fuel savings both to new vehicle buyers and to society. In the PRIA we relied on the mo st recent fuel price proj ections from the U.S. Energy Information Administration’s (EIA) Annual Energy Outlook (AEO) in analyzing the proposed standards. Specifically, the agency used the AEO 2008 Early Release forecasts of the Reference Case inflation-adjusted (constant-dolla r) retail gasoline and diesel fuel prices, which NHTSA stated represent the most up-to-date estimate of the most likely course of future prices for petroleum products. 34 In Jun 2008, EIA released the full AEO 2008 with an updated

34 U.S. Department of Energy, Energy Information Administration, Annual Energy Outlook 2008

, Early Release

, Reference Case Table 12. Available at http://www.eia.doe.gov/o iaf/aeo/pdf/aeotab_12.pdf (last accessed August 29, 2008). EIA released the full AEO 2008 in June 2008, wh ich NHTSA stated in the NPRM it would use in the final rule. EIA explained upon releasing the full AEO 2008 that it had been updated from the Early Release to reflectI-39

Reference Case, a Low Case, and a High Case. Federal government agencies generally use EIA’s projections in their assessments of future energy-related policies. We received a large number of comments indicating th at we should rely on the High Case for the final rule. There were a few comments favoring the reference case or other prices of gasoline. A summary of
their comments are:

Comment: Sierra Research, 2008-0089-0046, Pg. 77,

Do sensitivity analysis on fuel price using $2.50, $3.00, and $3.50

Comment: Consumer Federation of Amer ica, 2008-0089-0183 -pp. 45-46, 49-51

N HTSA’s price is not consistent with the re al world. EIA’s high price seems much more appropriate. EIA’s projections have been consistently low. They have been off by 35% but their projection for 2015 does not reflect this adjustment.

Comment: Environment America, National Wildlif e Federation, National Resources Defense Council, Pew Environment Group, Sierra Club, Union of Concerned Scientists, 2008-089-0119

NHTSA should use a higher price of gas

Comment: Members of Congress (21), 2008-0089-0145.1

NHTSA used EIA’s forecast of fuel prices th at range from $2.42 per gallon in 2016 to $2.51 in 2030. When compared to the prices at the pumps, these numbers are nothing short of absurd. For modeling purposes, NHTSA uses EIA’s higher gasoline price scenario, which ranges from $3.14 in 2016 to $3.74 in 2030 demonstrates that t echnology is available to cost-effectively achieve 35 mpg by 2015. On June 11, 2008, Guy Ca ruso testified before the House Select Committee on Energy Independence and Global Warming that NHT SA should use EIA’s higher gasoline price scenario in setting fuel economy standa rds. They urge us to promulgate final fuel economy standards based on the EIA’s high gasolin e price scenario (whi ch they understand will soon be revised) to comply with the EISA di rective that maximum feasible standards be required.

Comment: Air Resources Board, 2008-0089-0173, Pg 2.

Want NHTSA to use a higher price of fuel, at least the EIA high price case scenario.

NHTSA dramatically underestimated the future price of fuel. They provide several sources indicating higher fuel prices. EIA’s recent prope nsity to hurriedly revise its estimates upward, and EIA’s own recent forecast puts fuel at $3.92 /gallon in 2009, resulting in a significant divergence from their short term and long term forecast.

Comment: Air Resource Board, 2008-0089-0173.6, Pg. 8

EIA’s expectations of the effect of EISA, which was enacted after the Earl y Release was made public. The full
AEO 2008 is a vailable at http://www.eia.doe.gov/oiaf/aeo/pdf/0383(2 008).pdf (last accessed August 29, 2008).I-40

Absent supply disruptions, it wi ll be difficult to sustain oil prices above $100/barrel (2008 dollars) over the next 10 years. This is based on an analysis by the Federal Reserve Bank of Dallas that examined the impacts of expected fu ture demand, geopolitical factors, exchange rate movements, the ability of supp liers to meet demand, and non- conventional oil sources.

Comment: The City of Key West, 2008-0089-0182

Urges NHTSA to use $3.40 per gall on in setting standards.

Comment: Public Citizen, 2008-0089-0187

NHTSA’s sensitivity analysis shows that the level of fuel economy standards is highly sensitive to the price of gasoline. The agency’s estimate for the high pr ice scenario would set the car standard at 37.4 mpg in 2011, almost 20 percent higher than th e agency’s “optimized”
scenario.

Comment: Attorney General of th e States, 2008-0089-0199.1, Pg. 11

NHTSA acknowledges that a signif icant factor in the agency’s an alysis of maximum fuel economy is the price of gasoline. 73 Fed. Reg. at 24,476-1; see also PRIA at IX-1 2 (table IX- 5a). As such, it is important that future gasoline price es timates be the best available estimates. NHTSA used gasoline pric es of between $2.25 and $2.51 per gallon, depending on the future year. PRIA at VIII-20 (table VIII-3). This is startling, given that in June 2008 the national average price for gasoline reached $4.13 per gallon. See Energy Information Administration, Weekly Retail Gasoline and Diesel Prices (downloade d June 25, 2008 and enclosed). Unless NHTSA can provide publicly-available, mainstream docum entation supporting an al most fifty percent drop from current prices, it must substa ntially re-calibrate those estimates.

Comment: Union of Concerned Scie ntists, 2008-0089-0201.13, Pg. 24-25

NHTSA’s value for price of gasoline is too low. A more plausible, yet still conservative, estimate would be to average the past few yea r’s prices. The EIA estimates are too low given current oil prices, the increased global demand for energy from countries such as China and India, and the increased use of market mechanisms (such as emissions trading) to limit carbon
emissions.

Comment: Northeast States for Coordinated Air Use Management (NESCAUM), 2008-0089- 204.1, Pg. 2, Currently, the average price of a gall on of gasoline exceeds $4.00 and the principal reason given is high global demand in a supply constr icted market. There is little expectation that the gap between supply and dema nd will be narrowed in the foreseeable future. Therefore, assuming this reasoning is correct , the price of gasolin e should remain high; certainly well above the mid-$2.00 range. We urge NHTSA to reevaluate the effect of a wider range of gasoline prices to the $4.00 per gallon level and above. We would expect the re sults to show that there are more fuel savings technologies capable of cost-effectively achieving greater overall average fuel economy, even according to NHTSA’s conservativ e “net societal benefit” cost-analysis approach.

Comment: American Council for an Energy-E fficient Economy (ACEEE), 2008-0089-211.1I-41

Work with EIA to produce an up-to-date fuel pr ice projection for purposes of the final rule or, failing that, use the High Price projection from AEO 2008. EIA Administrator’s comments
before the House Select Committee on Energy Independence and Global Warming

“EIA's High Price forecast [does not] necessari ly capture fully current understanding of how high fuel prices are likely to be in the coming decades.”

Comment: State of Wisconsin Department of Natural Resources, 2008-0089-219.1

NHTSA should use the high price fuel scenario from DOE.

Comment: Center for Biological Di versity, 2008-0089-0222.1, Pg. 9-10

NHTSA’s price is too low and impossible to ju stify. NHTSA needs to run the model with today’s average gas price of $4.09/gallon. There is no indication that oil prices will subside in the long term. NHTSA needs to use reality-based inputs. Today’s gas price must be the starting point for the analysis.

Comment: National Automobile Dealer s Association, 2008-0089-223.1, Pg. 7

Fuel Prices Projected future fuel prices are critical to determini ng the value of fuel savings and
the cost beneficial fuel econom y standards for passenger cars a nd light trucks. To this end, NHTSA should continue to rely on the most recent reference case fuel price projections of the U.S. Energy Information Administration’s (EIA ). As demonstrated by the many years where EIA’s projections fell above or below reality, forecasting future fuel prices is by no means an exact science. Despite the inherent volatility or uncertainty of fuel prices, EIA and NHTSA would be remiss if they were to arbitrarily aband on the best models and data available or to use “high” or “low” price case projec tions that are inherently not pr obabilistic. For example, the use of a high price case to justify unduly costly CAFE standards coul d lead to decreased new motor
vehicle sales and a commensurate lower than projected rate of fu el energy savings and greenhouse gas reduction benefits.

Comment: Natural Resources Defense Council, 2008-0089 225.1, Pg. 2 – pp 2 following

NHTSA should use the higher fuel price estimate. NHTSA relies on the Energy Information
Administration’s Reference Case forecast for fuel prices. However, both the Reference and High Case forecasts have consistently underesti mated fuel prices and NHTSA must choose a
reasonable forecast consistent w ith likely pri ce trajectories.

Comment: Sierra Club, 2008-0089-0226.1, Pg. 2, 4-5

NHTSA’s price is too low. At a minimum NHTSA should use th e high EIA forecast. NHTSA should examine other fuel price estimates, such as the oil futures mark et price predictions.

NHTSA’s prices are not consistent with today’s gas prices, futu res market projections or the assessment of the EIA Administrator that higher prices are more appropriate to setting the standards. EIA has vastly underestimated the pr ice in recent years. Secr etary Peters commentedI-42

on the oil price problem. The oil futures market price predictions run consistently above $130 per
barrel.

Comment: U.S. Senate, 2008-0089-0454, Pg. 1, 4

NHTSA’s gas prices are far below what consumer s are paying today, and we do not believe it’s reasonable to assume that the price of gas will drop precipitously, as NHTSA has done. Guy Caruso told Congress that NHTSA should use th e EIA high price. NHTSA’s treatment of gas prices would put the rule at substantial litigation risk.

Agency response: NHTSA has carefully considered av ailable evidence, recent trends in petroleum and fuel prices, and the comments it received on the NPRM analys is. After doing so, NHTSA has decided to use EIA’s High Price Case forecast in its final rule analysis and to determine the MY 2011 CAFE standards. As NHTSA recognized in the NPRM, commenters are correct that projected future fuel prices have the largest effect of all the economic assumptions that NHTSA employs in determining benefits both to new vehicle buyers and to society, and thus on CAFE stringency. This is why it is vital that NHTSA base its fuel price assumptions on what it believes to be the
most accurate forecast available that covers th e expected lifetimes of MY 2011 passenger cars and light trucks, which can extend up to 25-35 ye ars from the date they are produced. The long time horizon of NHTSA’s analysis also makes it cr itical that the agency not rely excessively on current price levels as an indicato r of the prices that ar e likely to prevail over an extended future period. Instead, NHTSA re lies largely on EIA’s professional e xpertise and extensive experience in developing forecasts of future trends in en ergy prices, as do most other federal agencies.

In addition, NHTSA notes that several manufacturer s employed fuel prices consistent with or exceeding the AEO 2008 High Price Case for the time period covered by the rulemaking in their revised product plan estimates of fuel economy a nd sales for individual models. If the agency employs fuel price forecasts that differ from those used by manufacturers, it may incorrectly attribute the fuel savings resu lting from increased market demand for fuel economy to higher CAFE standards, or conversely, underestimate the fuel savings resulting from increased standards by attributing too mu ch of the increase in fuel economy to higher market demand. Given manufacturers’ assumptions about fuel prices, the agency’s estimates of fuel savings and economic benefits resulting from the standards adopted in this final rule are conservative, because they are likely to underestimate fuel savi ngs attributable to the increase in fuel economy
above its market-determined level that CAFE standards will require.

Although some commenters suggested that NHTSA develop its own fuel price forecasts based on then-current pump prices, NHTSA does not believ e that it has the independent capability to provide a more reliable prediction of future fuel pr ices, or that it would have the credibility of
EIA’s forecasts. If NHTSA had assumed that th at fuel prices would remain at their mid-2008 peak levels throughout the lifetim es of MY 2011 cars and light tr ucks, the agency would have
overvalued the benefits attributed to fuel savings, and thus like ly have established excessively stringent standards. While petroleum prices were rising at the time the NPRM was published, eventually reaching nearly $140 pe r barrel, since then global aver age prices for crude oil haveI-43

declined to levels as low as $35 per barrel. 35 The recent extreme volatility in petroleum and fuel prices illustrates the danger in relying on current prices as an indicato r of their likely future levels, and gives NHTSA greater confidence in re lying on EIA’s forecasts of future movements in fuel prices in response to changes in demand and supply conditions in the marketplace. While NHTSA also agrees with the commenters that the sensitivity analysis demonstrates that higher CAFE standards could be established if higher fuel price assumptions were employed, the agency cannot simply choose to employ higher fuel price assumptions becaus e it wishes to raise CAFE levels. Doing so would be inconsistent with the agency’s approach of using what it
concludes is the most reliable estimate of the benefits from conserving fuel when establishing fuel economy standards. NHTSA recognizes that predicting future oil prices is difficult, particularly during periods when world economic conditions are as volatile as they are today. Nevertheless, NHTSA continues to believe that EIA’s fuel price fo recasts as reported in its AEO represent the most reliable estimates of future fu el prices, and thus of the benefits from reducing fuel consumption through higher CAFE standa rds. While NHTSA recognizes that other forecasts exist, the agency believes the EIA for ecasts are preferable for its purposes, since they are the product of an im partial government agency with consid erable and long-standing expertise in this field. Any simple extrap olation of current or recent re tail fuel prices, which commenters recognize have shown extreme volatil ity in recent months, is likely to provide a considerably less reliable forecast of future prices than the cu rrent AEO. Each time EIA issues a new AEO, it considers recent and likely future developments in the world oil market, the effect of the current geopolitical situation on oil s upply and prices, and conditions in the domestic fuel supply industry that affect pump prices. 36

For example, the Overview section to AEO 2008 states that because EISA was passed between the Early Release and the time of publication for AEO 2008, EIA updated th e Reference Case to reflect the impact it expected EISA to have on fu el prices. EIA also updated its projections for
the AEO 2008 Reference Case “to better reflect tr ends that are expected to persist in the economy and in energy markets,” including a lower projection for U.S. economic growth (a key determinant of U.S. energy demand), higher price projections for crude o il and refined petroleum products, slower projected growth in energy demand, higher foreca sts of domestic oil production (particularly in the near term), and slow er projected growth in U.S. oil imports. 37 Thus NHTSA
is confident that EIA is aware of and has accounted reasonably for current political and economic conditions that are likely to affect future trends in fuel supply, demand, and retail prices.

Although a majority of commenters asserted that EIA’s Reference Case forecast is likely to underestimate future fuel prices significantly, an d that NHTSA’s reliance on the Reference Case resulted in insufficiently string ent proposed CAFE standards, th ey did so in an environment

35 Energy Information Administration, World Crude Oil Prices, data for week ended 1/2/2009, available at http://tonto.eia.doe.gov/dnav/pe t/pet_pri_wco_k_w.htm (last acce ssed February 12, 2009).

36 AEO 2008 states as follows with regard to factors which EIA accounts for in developing the Reference Case: As noted in AEO2007, energy markets are changing in response to readily observable factors, which include, among others: higher energy prices; the growing influence of developing countries on worldwide energy requirements; recen tly enacted legislation and regulations in the United States; changing public perceptions on issues related to emissions of air pollu tants and greenhouse gases and the use of alternative fuels and; and the economic viability of various energy technologies.

37 AEO 2008 Overview, at http://www.eia.doe.gov/oia f/aeo/overview.html (last accessed October 10, 2008).I-44

when retail fuel prices were at or above $4.00 per gallon. Many commenter s stated that at a minimum, NHTSA should use EIA’s High Price Case as the source for its fuel price forecasts, primarily because those appeared to be more cons istent with then-current fuel prices. As one illustration, NRDC cited EIA’s own Internat ional Energy Outlook 2008, published the same month as the AEO 2008, which stat ed that given “...current mark et conditions, it appears that world oil prices are on a path that more closel y resembles the projecti on in the high price case
than in the reference case.” 38 Commenters also cited EIA Administrator Caruso’s June 2008 statement that “We’re on the higher price path right now. If you were to ask me today what I would use, I would use the higher price.” NHTSA also notes that several manufacturers in their confidential product plan submissions indicated that they had based their product plans on gas price estimates that were either between EIA’s Reference and High Price Cases, or above even the High Price Case.

The AEO High Price Case is best understood in th e context of its relati onship to the Reference
Case. EIA described the Referen ce Case as follows in AEO 2008:

The reference case represents EIA’s curre nt judgment regard ing exploration and development costs and accessibility of oil resources in non-OPEC countries. It also assumes that OPEC producers will choose to maintain their share of the market and will schedule investments in incremental production capacity so that OP EC’s conventional oil production will represent about 40 percent of the world’s total liquids production. 39

In contrast, EIA describes its Low Price case in the following terms:

The low price case assumes that OPEC count ries will increase their conventional oil production to obtain approximately a 44-percen t share of total world liquids production,
and that conventional oil resources in non-OPEC countries will be more accessible and/or less costly to produce (as a re sult of technology advances, more attractive fiscal regimes, or both) than in the reference case. With these assumptions, non-OPEC conventional oil production is higher in the low pri ce case than in the reference case. 40

Finally, EIA describes its High Price case as follows:

The high price case assumes that OPEC countri es will continue to hold their production at approximately the current rate, sacrificing market shar e as global liquids production
increases. It also assumes that oil resources in non-OPEC countries will be less accessible and/or more costly to produce th an assumed in the reference case. 41

As these descriptions emphasize, EIA’s Low and High Price Cases are based on specific assumptions about the possible behavior of oi l-producing countries and future developments affecting global demand for petroleum energy, a nd how these might differ from the behavior

38 Energy Information Administration (2008) International Energy Outlook 2008: Complete Highlights. June 25.

39 AEO 2008, at 199. Available at http://www.eia.doe .gov/oiaf/aeo/pdf/0 383(2008).pdf (last accessed October 10, 2008).

40 Id

. 41 Id

.I-45

assumed in constructing its Reference Case. Ho wever, this distinction does not necessarily imply that EIA expects either its Low Price or Hi gh Price Case forecast to be more accurate than its Reference Case forecast, since EIA offers no assessment of which set of assumptions underlying its Low Price, Refere nce, and High Price cases it believes is most reliable.

EIA did recognize that world oil prices at the time the final version of AEO 2008 were above even those forecast in its High Price Case. Howeve r, it attributed this situation to short-term developments, most or all of which were likely to prove transitory, as ev idenced by its statement
in the Overview to AEO 2008:

As a result of recent strong economic grow th worldwide, transitory shortages of experienced personnel, equipment, and cons truction materials in the oil industry, and political instability in some major producing regions, oil pric es currently are above EIA’s estimate of the long-run equilibrium price. 42

This observation is consistent with EIA’s statem ent in IEO 2008 that current market conditions appeared to place world oil prices on a path clos er to the High Price Case than the Reference Case. While EIA clearly expects prices to remain high in the near term, this does not necessarily imply that it expects its High Pr ice Case forecast to be more reliable over the extended time horizon spanned by AEO 2008.

NHTSA has seriously considered the comments it rece ived on the fuel price forecasts used in the NPRM analysis, and paid close attention to recen t developments in the world oil market and in U.S. retail fuel prices. The agen cy has also reviewed forecasts of world oil prices and U.S. fuel prices available from sources other than EIA, as well as the views expressed by petroleum market experts, professional publications, and press reports. 43 The agency notes that although both the views of experts and projections of petroleum prices diffe r widely, the emerging consensus appears to be that world petroleum and U. S. retail fuel prices are likely to remain at
levels that are more consistent with those fo recast in the AEO 2008 High Price Case than with
the Reference Case forecasts over the foreseeable future. 44 Over the period from 2011, when the standard s adopted in this final rule would take effect, and 2030, the outer time horizon of the AE O 2008 forecasts, retail gasoline prices in the

42 Id ., at 5.

43 These include EIA, Short-Term Energy Outlook, various issues, available at http://www.eia.doe.gov/emeu/st eo/pub/contents.html (last accessed Nove mber 13, 2008); International Energy Agency, World Energy Outlook 2008 , summary available at http://www.iea.org/Textbase/npsum/W EO2008SUM.pdf (last accessed Nove mber 13, 2008); AJM Petroleum Consultants, The AJM Price Forecast, available at http://www.ajmpetroleumconsultants.com/index.php?page=priceforecast (last accessed Novemebr 13, 2008); PetroS trategies, Inc, Survey of Oil Price Forecasts, available at http://www.petrostrategi es.org/Graphs/Oil_Pri ce_Forecasts.htm (last accessed Nove mber 13, 2008); International Monetary Fund, World Economic Outlook, October 2008, Chapter 3: Is Inflation Back? Commodity Prices and Inflation, available at http://www.imf.org/external/pubs /ft/weo/2008/02/pdf/c3.pdf (last accessed November 13, 2008); and Federal Reserve Bank of Dallas Economic Letter, Volume 3, No. 5, May 2008, available at http://www.dallasfed .org/research/eclett/2008/e l0805.html (last accessed November 13, 2008).

44 In the AEO High Price Case, prices for imported petroleum are projected to average about $75 per barrel over the next 10 years, while U.S. retail gaso line prices are forecast to average $2.90 per gallon over that same period; see AEO 2008, High Price Case Table 12, available at http://www.eia.doe.gov/oiaf/aeo/excel/aeohptab_12.xls (last accessed October 19, 2008).I-46

AEO 2008 High Price case are projected to rise steadily from $2.95 to $3.62 per gallon, averaging $3.28 per gallon (all prices expres sed in 2007 dollars). For the years 2031 and beyond, the agency’s analysis assumes that retail fuel prices will remain at their forecast values for the year 2030, or $3.62 per gallon. These pri ces are significantly hi gher than the AEO 2008 Revised Early Release Reference Case forecast used in the agency’s NPRM analysis, which averaged $2.34 per gallon (in 2006 dollars) over that same period. 45 After deducting state and federal fuel taxes, this revised forecast results in an average value of $3.08 per gallon of fuel saved over the lifetimes of 2011 passenger cars a nd light trucks. Because of the uncertainty surrounding future gasoline prices, the agency al so conducted sensitivity analyses using EIA’s
Reference and Low Price case fore casts of retail fuel prices. NHTSA is aware that EIA recently released a preliminary version of its Annual Energy Outlook 2009, which appears to confirm then-EIA Administrator Caruso’s testimony before the House Select Committee in June 2008 that the future path of gasoline prices likely more closely resembles the AEO 2008 High Price Case than th e 2008 Reference Case. However, the agency has elected not to use this newly-available forecast of fuel prices, in part because it did not have adequate time to replicate the entire analysis repor ted in this rule using re vised forecasts of fuel prices. 46 Moreover, the forecast of gasoline pric es from AEO 2009 Early Release averages $3.45 over the period from 2009-30, only slightly higher than the comparable figure for the AEO 2008 High Price forecast the agency relied upon in pr eparing this analysis. Thus incorporating EIA’s newest forecast would be unlikely to ha ve an effect on the fuel economy standards adopted in this rule. In its future CAFE rulemaking activities, th e agency will continue to rely on EIA’s Annual Energy Outlook as its primary source for fuel price forecasts. As indicated previously,
NHTSA continues to believe that the for ecasts reported in EIA’ s Annual Energy Outlook represent the most suitable estimates of future fuel prices for the purpose of assessing the economic benefits from reducing fuel consum ption through higher CAFE standards. Under normal conditions, the agency is likely to view EIA’s Reference Case forecast as the most reliable basis for estimating benefits from reduc ing future fuel consumption, although the agency will retain the option of drawing its forecasts from other scenarios presented in AEO if, as here, it deems that circumstances warrant. The agency will also continue to monitor fuel price forecasts available form other forecasts, and to consider their implications for its choice among alternative price scenar ios developed by EIA.

45 The fuel price forecasts reported in EIA’s AEO 2008 Revised Early Re lease and Final Release reflect the estimates effects of various provisions of EISA – including the requirement to achieve a combined CAFE level of 35 mpg by model year 2020 – on the demand for and supply of gasoline and other transportation fuels. Thus the fuel price forecasts reported in these versions of AEO 200 8 may already account for th e reduction in fuel demand expected to result form the CAFE standards adopted in this Final Rule, whereas the agency’s analysis of their effects would ideally use fuel price forecasts that do not assume the adoption of hi gher CAFE standards for model years 2011-20. However, the agency notes that the differen ce between the Reference Case forecasts of retail gasoline prices for 2011-30 between EIA’s Early Release of AEO 2008, which did not incorporate the effects of EISA, and its subsequent Revised Early Release, which did reflect EISA, averaged only $0.0004 ( i.e. , less than one-half cent) per gallon over the period 2011-30, This suggests that accounting for the effect of EISA would have had only a minimal effect on the fuel price forecasts used in this analysis.

46 U.S. Energy Information Administration, Annual Energy Outlook 2009 Earl y Release, available at http://www.eia.doe.gov /oiaf/aeo/index.html (last accessed February 12, 2009).I-47

Product restrictions

Comment: Recreation Vehicle Industry Associ ation (RVIA), 2008-0090 229, Pg. 3-5 wants a 3.2% adjustment in the curve for “heavy tow capa ble” vehicles if its Trailer Weight Rating is equal to or greater than 7,700 lbs. per the SAE J2897 recommended practice. 75% of RVIA product in any year are towable pr oducts, travel trailers, pop-up campers, truck campers, or fifthwheel trailers. In order to safety tow and stop th ese vehicles they need a truck that is properly equipped. An aggressive CAFE st andard will force manufacturers to scale back vehicle power or make weight based changes to SUVs and light tr ucks. If there is a se rious sales impact, there is a serious possibility that to wable RV industry sales will be im pacted. Given that towable RV shipments were 261,000 units and thousands of Am erican workers produce those units, NHTSA cannot overlook the impact of its proposal no RV industry jobs and sales.

Trailers owners will have four choices, retail older tow vehicles, use li ght weight under powered vehicles, purchase larger trucks (over 8,500 lb s. GVWR), or abandon their vehicles.

Agency response: The agency’s methodology for setting th e standards gives appropriate weight to and already accounts for towing needs.

Rebound Effect

Comment: Mark A. Delucchi, 2008-0089-0025 Pg. 1. W ithout giving a specific figure this
commenter stated that the rebound effect coeffi cient should be lower th an the value used by NHTSA because more weight should be given to the Small and Van Dender study. He also noted that Hughes et al. recently found a very low short-run price elasticity of demand for gasoline [The Energy Journal, 29(1), January 2008]. 47

Comment: Sierra Research, 2008-0089-0046-1, Pg. 74. Based on a 1999 paper by Greene of Oak Ridge National Laboratory 48 , the rebound effect is 20%, they use a “conservative” 17%. As Greene explains, it is well documented that increased fuel economy produces a long term rebound effect of 20%. In other words, a 100% improvement in fuel economy induces a 20%
increase in vehicle travel.

Comment: Air Resources Board, 2008-0089-0173-1, P g. 10. The California Air Resources
Board states that NHTSA “declines to adopt two critical findings from previous analysis: 1) the
future decline in value of rebound e ffect as household real income in creases, and 2) as fuel prices

47 2008 Volume 29 Number 1 Evidence of a Shift in the Short-Run Price Elasticity of Gasoline Demand Jonathan E. Hughes*, Christopher R. Knittel** and Daniel Sperling*** Understanding the sensitivity of gasoline demand to changes in prices and income has important implications for policies related to climate change, optimal taxation and national security. The short-run price and income elasticities of gasoline demand in the United States during the 1970s and 1980s have been studied extensively. However, transportation analysts have hypothesized that behavioral an d structural factors over the past several decades have changed the responsiveness of U.S. consumers to change s in gasoline prices. We compare the price and income elasticities of gasoline demand in two periods of similarly high prices from 1975 to 1980 and 2001 to 2006. The short-run price elasticities differ considerably: and range from -0.034 to -0.077 during 2001 to 2006, versus -0.21 to
-0.34 for 1975 to 1980. The estimated short-run income elas ticities range from 0.21 to 0.75 and when estimated with the same models are not significantly different between the two periods.

48 David L. Greene, et al, “Fuel Economy Rebound Effect for U.S. Household Vehicles”, The Energy Journal, Vol. 20, No. 3, 1999.I-48

increase, people are forced to spend a larger sh are of their income on fuel, thus becoming more sensitive to fuel prices. The Air Resources Boar d recommends a rebound effect in the range of a maximum of 10 per cent.

Comment: Air Resources Board, 2008-0089-0173.15. In an additional comment by the Air Resources Board, testimony by Small is cited to show a marked decline in rebound effect for California to 1% for a single year vs. 4.9% in the years 1975- 2001. A number of variables and
additional effects to rebound were modeled and given in Small’s testimony. While no clear recommendation is given for a change in NHTSA’s value for rebound effect, the clear implication is that the valu e should probably be lower.

Comment: Alliance, 2008-0089-0179.1, P9, Att3 S-8. In this attachment to other comments by the Alliance a supporting study by NERA is summ arized. NERA cites four economic effects
which increase external costs and one effect wh ich reduces external costs as being directly impacted by a higher rebound effect. The primary di scussion is on net bene fits with respect to the Volpe model; and NERA provides data which in creases overall costs due to an assumption of a higher rebound effect of 20%.

Comment: Public Citizen, 2008-0089-0187, Pg. 4. This commenter states that NHTSA has “assumed a very high rebound effect – 15 percen t.” Furthermore, it is stated that NHTSA looked at 29 estimates and attempts to reflect the curre nt conditions; however according to the Small and Van Dender study, “most empirical measurements of the rebound effect rely heavily on variations in the fuel price,” which rai ses again the question of whether NHTSA’s assumptions about the rebound effect are colored by the es timates of future fuel price.

Comment: Union of Concerned Scientists 2008-0089-0201. 7, Pg. 1 etc. and Union of Concerned Scientists, 2008-0089-0201.11. These comments fo cus on a paper authored by Kenneth Small and Kurt Van Dender, prepared for the State of California Air Resources Board, the California Environment Protection Agency, a nd the California Energy Commission. The article attempts to estimate the magnitude of rebound effect in th e short-run and long-r un rebound effect using
cross-sectional time series U.S. data from 1966- 2001. For the U.S. as a whole authors estimate a rebound effect of 5.3 % in the short run, and 26% fo r the long run, with the latter estimate very
similar to the consensus from the authors’ litera ture review. The authors also conclude that the
rebound effect declines with incr eases in income. The estimat es of the rebound effect during future years presented in this study are specific to California, in that th ey reflect California household incomes, fuel prices , and fuel economy, and in any case have been superseded by several updates to the original study published by Small and Van Dender, CARB, and EPA.

Comment: Environmental Defense Fund, 2008-0089- 0224.1, Pg. 3. NHTSA selected the rebound effect of 15 per cent based on the re view of studies conducted from 1983 through 2005. However, a recent literature review suggests that many previous studies overestimated the rebound effect because of problems with model speci fication. Also, latest research work suggests
that the rebound effect decrease s over time with rising income.

Agency response: The rebound effect is generally consider ed to be that effect where an improvement in fuel economy induces a percen tage increase in demand for vehicle travel. Considering the empirical evidence on the rebou nd effect as a whole, but according greaterI-49

importance to the updated estimates from st udies allowing the rebound effect to vary – particularly the Small and Van Dender study – NHTSA originally proposed a final rebound value of 15 percent to evaluate the fuel savings and ot her effects of alternativ e standards for the time period covered by this rulemaking.

Of the 7 organizations commenting on the subj ect of rebound effect, 2 recommended a higher
value and 5 recommended a lower value than the 15 per cent used by NHTSA. NHTSA had previously evaluated 22 studies containing 66 estimates cove ring the period 1983 to 2005 to determine the basis for selecting a single value for rebound effect. NHTSA tentatively attached 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. Recently, a review of this by NHTSA with other agencies and co nsultants has determined that in light of previous studies and
the fact that net benefits will be determined on the basis of rebound effect, the value of 15 per cent will be used for the final rule. (See Chapter VIII for more discussion about the rebound effect.)

Regulatory Flexibility Analysis

Comment: National Automobile Dealers Associa tion, 2008-0089-223.1, Pg. 9 stated that a full regulatory flexibility analysis must be undertaken. Many of the nation’s deal erships are directly impacted by the proposal and are small busines ses as defined by the SBA. Moreover, the overwhelming majority of these dealerships have 200 employees or less, that standard established by DOT in a recently published rule th at examined that issu e (72 Federal Register 15614-7 (April 2, 2007). Therefore, a full regulatory flexibility an alysis must be undertaken to examine what modifications may be necessary to lessen the regulation’ s potential impact on motor vehicle dealerships.

Agency response: Dealers are not directly impacted by th e CAFE rules, they are indirectly impacted. Dealers are not a regu lated entity under CAFE.

Retail Price Equivalent Multiplier

Typically cost estimates for technologies, for example when the agency has a cost tear down study for a safety countermeasure, are provided on a variable cost basis. NHTSA applied an indirect cost multiplier in the NPRM of 1.5 to th e estimate of the vehicle manufacturers’ direct costs for producing or acquiri ng each fuel economy-improving/CO 2 emission-reducing technology. Historically for safe ty and fuel economy purposes, NHT SA used an almost identical multiplier, 1.51, for the markup from variable cost s or direct manufacturing costs to consumer costs. The markup takes into account fixed co sts, burden, manufacturer’s profit, and dealers’ profit. NHTSA’s methodology for determining this markup was peer-reviewed. This value is
based on an examination of au to industry financial reports 49

.

Comment: The Alliance 2008-0089-0169.1 cited the Mart ec Cost study and stated that the agency should use a 2.0 Retail Price Equivalent (RPE) markup factor. In order for a company to

49 Spinney, Bruce C., CPA, NHTSA “Advanced Air Bag System Cost Weight and Leadtime Analysis Summary Report” Docket No. 2007-27453-10.I-50

remain financially viable, that Retail Price Equivalent (RPE) markup factor must be at least 2.0. This estimate of RPE was documented by Dr. Winn V. Bussmann in a subm ission that provided a correction to the earlier Jack Faucett study. In addition as part of that submission, Dr. Bussmann
also showed with more recent financial data that an estimate of 2.0 for RPE is still valid. Commodity prices for many of the materials necessary for these technologies ha ve increased dramatically in the last two year s and are at record high s. These prices are significant factors in determining manufacturing variable costs.

The Alliance 2008-0089-0179.1, P6, P17, Attachment 2 P1,

The Alliance believes the retail price equivalent markup should be 2.0, not 1.5, based on

Wynn V. Bussman, “Study of Industry-Average Mark-up Factors to Estimate Retail Price Equivalents”, Jan. 24, 2008, and Attachment 4. Also, Argonne Nati onal Laboratory report recommended 2.0. NHTSA misused the Argon ne report by citing 1.5 RPE for outsourced components. See Sierra Report Attachment at 61.

Agency Response: The agency disagrees with a 2.0 RPE. Commodity prices do not affect the RPE. NHTSA has its own report on mark-up factors ju stifying 1.51 that we rely upon. This report implicitly includes historical levels of outsourced components.

Comment: Alliance, 2008-0089-0195.1, Attachment 4, P1-3

The Jack Faucett Associates (JFA), used by a draft EPA staff report in 2005 (EPA420-R-05-012) analysis that estimates a mar kup factor of 1.26 does not accurate ly account for full costs. The work done by Sierra Research indicates a mark-u p factor of at least 2.0 would be necessary. JFA failed to recognize that research and development and other indirect costs were combined with direct manufacturing costs. JFA also assumed that emission control equipment does not change dealer overhead expenses. The author of the st udy has agreed that the study underestimates the markup factor. Correcting the pr oblems would result in a markup factor of at least 1.7.

The CARB justification for its markup of 1.4 is that it fell between the 1.26 factor and 1.5 suggested in a paper published by Argonne National Laboratory. CARB apparently misinterpreted Argonne’s reference to a 1.5 ma rkup factor, which would be appropriate for certain categories of components, such as batter ies that are developed en tirely by vendors. The same paper makes it clear that the markup for en gines and transmissions primarily developed by
OEMs would be 2.0 to 2.05.

The NRC and NESCCAF markup fact ors of 1.4, are contributed to a consultant Mr. Duleep, who
has since testified that “1.4 might represent the lo w end of the scale of markups” and that markup factors as high as 2.0 would be a ppropriate for certain items.

Pg. 11, Dr. Bussmann estimates inbound and outbound transportation costs at 6% of direct manufacturing costs.

Agency response: NHTSA has used a RPE of 1.51 for y ears and agreed with EPA to use 1.5 for this rulemaking. The commenter does not analyze NHTSA’s methodology.I-51

Comment: The Air Resources Board, 2008-0089-0173, p 8, stated that

NHTSA’s RPE methodology is unsound. The cost to incorporate a tec hnology is the same regardless of vehicle production. NHTSA’s a pproach implies an engineering cost of $35.2 million for a vehicle model with 50,000 unit production, but $352 million for a vehicle model with 500,000 production.

Agency response: The markup is for many other factors than just engineering costs. It includes all fixed costs, manufacturer profit and dealer profit.

Comment: Air Resources Board, 2008-0089-0173.4, P4

ARB objects to Sierra’s RPE of 2.0, and suggest s adjustment to 1.4. They argue that many components are sourced to suppliers. Since th e manufacturer doesn’t be ar the burden of R&D and investment and some level of warranty, a 2.0 markup is not appropriate and should be adjusted to 1.4.

Agency response: NHTSA’s 1.5 RPE includes the histor ical levels of outsourcing.

Comment: Northeast States for Coordinated Air Use Management (NESCAUM), 2008-0089- 204.1, Page 4, All reported costs and benefits, at tributed to NESCCAF by NHTSA, should be reviewed carefully for errors and am ended accordingly, using a 1.4 RPE not 1.5. Information from a 2004 NESCCAF5 study entitled “Reduc ing Greenhouse Gas Emissions from Light-Duty Motor Vehicles” is cited in the NHTSA proposal. Some of this information is reported in a way that is either confusing or inco rrect. For example, NHTSA app lies a 1.5 retail price equivalent (RPE) factor to the manufacturer costs presented in Appendix C of the NESCCAF report, and at other times uses a 1.4 RPE – and presents both costs as NESCCAF costs. In the report, NESCCAF only used a 1.4 RPE. The reporting of costs using the 1.5 multiplier as NESCCAF costs is incorrect and leads to uncertainty as to how the costs were developed. A specific case is the cost of a turbocharger. NHTSA states the NE SCCAF turbocharger cost is $600. In this case, NHTSA applied a 1.5 RPE factor to manufactur er costs presented in Appendix C of the NESCCAF report to arrive at th e $600 cost. This is different from the cost that NESCCAF developed. Conversely, on page 24369 of the Federal Register notice, NHTSA accurately states the NESCCAF cylinder deactivation costs range d from $161 to $210. This cost accurately reflects manufacturer costs presented in Appe ndix C of the NESCCAF report, multiplied by the 1.4 retail price equivalent used by NESCCAF.

Agency response: NHTSA notes that the analysis for this final rule relies on entirely new cost estimates for fuel economy technologies develo ped by the agency in response to comments and in coordination with an international engineeri ng consulting firm, Ricardo, Inc., based on a bill of materials approach and not based on the 2004 NESCCAF study, so the issue of apparent inconsistency in the RPE factor applied to those estimates noted by NESCAUM and CARB is no longer relevant. The agency also notes that both the production and application of fuel economyimproving technologies include se parate engineering cost co mponents. Developing these technologies and readying them for high-vol ume production entails significan t initial investments in product design and engineeri ng, while as the NPRM pointed out, applying individual technologies to speci fic vehicle models can entail significant additional costs forI-52

accompanying engineering changes to its existi ng drive train, development and testing of prototype versions, recalibrat ing engine operating parameters , and integrating the technology
with other attributes of the ve hicle. While design and engine ering costs for developing fuel economy-improving technologies are included in the production cost estimates for individual technologies, additional engineeri ng costs incurred by manufacturers in applying them to specific
vehicle models are included in NHTSA’s estimate of the RPE factor. Fi nally, the agency notes
that its estimate of the RPE factor includes is consistent with high-volume production and application of fuel economy t echnologies, because it assumes that initial design and engineering costs to develop and begin production of thes e technologies will be recovered over large production volumes. Thus, NHTSA believes thatCARB’s concerns about potential doublecounting of engineering costs for developing and applying fuel economy technologies reflect a failure to recognize that engineer ing costs arise in both their de velopment and application. The agency also believes that CARB’s concern a bout whether NHTSA’s RPE factor assumes the spreading of initial design and engineering costs for developing these technologies over insufficiently high production volumes is unfounded.

In response to the concerns expressed by the Alli ance and others that NHTSA ’s RPE factor is too low, the agency notes that the RPE factor of 2.0 reported in the Argonne and Sierra Research studies includes various categor ies of production overhead costs (for product development and engineering, depreciation and amortization of production facilities, a nd warranty) that are included in NHTSA’s estimates of production costs for fuel economy technologies. When applied to technology production co sts defined to include these components, the agency’s RPE factor of 1.5 is thus consistent with full recovery of these cost components. This conclusion is independent of whether overhead costs for de veloping and producing fuel economy technologies are initially borne by equipm ent suppliers or by vehicle manufacturers themselves. Consequently, NHTSA has continued to employ an RP E factor of 1.5 in its analysis for this final
rule.

Comment: National Automobile Deal ers Association, 2008-0089-223.1, P 7

When calculating fuel economy technology costs, NHTSA uses a 1.5 multiplier to account for related additional costs, includi ng “dealer profit.” NHTSA should review whether its estimates
include all dealer costs-of–sales when calculating “deal er profit” and the extent to which it has properly accounted for the finance costs cons umers typically pay when purchasing new automobiles. NADA would be happy to meet with NHTSA staff to discuss these issues further.

Agency response: The dealer markup does not include finan ce costs. Those are not a societal cost but a transfer payment from the purchaser to the lender.

Sales Impacts and Related Employment Impacts

In the NPRM the agency presented an analysis of how sales and employme nt might be affected by higher fuel economy standards. The standards are expected to increase the price of passenger cars and light trucks, while redu cing fuel expenditures in the future. Because the proposed alternative is based on a marginal cost/marginal benefit analysis, sales were estimated to slightly increase under this scenario. In other words, consumers would believe they would save more in fuel economy expenditures in the future than the initial price increase of the vehicle.I-53

Comment: The Alliance 2008-0089-0179.1, P5, P44 (gives table), Att3, S6-7, Att3 S5, 17, A-1-9 presents the results of an analysis by NERA which finds that NHTSA’s proposed standards would reduce the sales of new vehicles by 856,000 and create associated job losses of 82,000.
NERA finds that NHTSA’s sales increase make s no economic sense. Where is the market
failure? NERA has a new vehicle market mode l. If improving fuel economy would increase sales, why haven’t manufacturers included these m easures in their plans? NHTSA has either overestimated benefits or underestimated costs, or both.

Agency response: NHTSA consulted with a contractor to examine benefit and cost estimates. The commenter offers no advice on how to change the NHTSA analysis.

Comment: Ford, 2008-0089-0202.1, pp 5-6 believes that the combination of benefit overestimation, misunderstanding of our curren t technology deployment, and specific technology incompatibilities has led to an over-estimati on of the potential fuel economy improvements on Ford's products. Ford be lieves there will be a l oss of sales due to overe stimation of technology application for benefits.

It is a common practice to use hedonic pricing technique ..[which] determines the price of a vehicle by the characteristics of the car such as towing, cargo volume, performance etc. We recommend that NHTSA modify its analysis to in corporate this technique into its analysis.
NHTSA treated the difference between the techno logy costs (of increasing the fuel economy of each vehicle model) and value of fuel savings as the "effective price" to vehicle buyers. The "effective price" calculated was then assumed to represent consumer valuation of fuel economy. This is conceptually inaccurate. First, it was implicitly assumed that the technology costs incurred by the manufacturers can be fully passe d on to buyers. In the competitive environment of the U.S. automotive market, this is not true. Second, using alte rnative gasoline price assumptions will change the estimates of "effective price". A higher gasoline price assumption will lower the effective price estimates, holding everything else constant. The Sierra Research Inc. (Sierra) analysis, dated June 26, 2008, estimates that a cons umer would not breakeven over a 20 year period unless gas prices are sustained at $4.47 a gallon. Sierra al so concluded that by using a more conservative payback period of 5 years the estimated breakeven gas price would have to be $6.59.

Agency response: The agency does not believe it needs a hedonic pricing technique. We are estimating the incremental costs and benefits to the same make/model by adding fuel economy technologies only. All other parts of the vehicl e are not impacted and we hold the performance of the vehicle at an equivalent level. Inputs to the model (e.g. the price of technology, the price of gasoline, etc.) do change the results. So, wh en Sierra Research assumes higher prices and lower effectiveness for various technologies, it is easy to see how their results would be very different. Assuming that manufacturers cannot pass on price increases to consumers has important implications for the au tomobile manufacturers, but in th is analysis it makes it a better
deal for consumers and sa les should increase.

Comment: The Consumer Federation of Amer ica, 2008-0089-0183-pp. 22, 43 states that NHTSA ignores that pushing the industry to prod uce more fuel efficient cars might improve employment opportunities by better aligning supply and demand. NHTSA has it backwards. ItI-54

is more likely that the absence of significantly increasing fuel ec onomy standards in the past half decade has led to significant sa les losses, than vice versa.

Agency response: From an industry perspective, sales ha ve been at an all-time high in recent years. Only in the last two years when the price of gasoline went up greatly would a better alignment of supply and demand for more fuel efficient vehicles have improved sales.

Comment: The United Auto Workers (UAW) 2008-0089-0226.3, pp 2, is concerned the NPRM could lead to more job loss and threaten health care coverage for retir ees of the Detroit-based mfrs. The CAFÉ increase would impose enormous, separate retooling costs on these companies. In light of the serious economic difficulties already facing these fi rms, this could lead to even more job loss and potentially threaten health care coverage for over half a million retirees and
their families.

Agency response: As discussed by the larger companies, the footprint attribute-based system is an advantage over the flat rate standards. If the American companies do not improve fuel economy and lose market share, the job losses may be even more.

Safety standards impact on vehicle weight, or fuel economy

All of the vehicle weight comments were confidential. S ee Chapter IV.

Size/safety Impacts

See Chapter IV

Uncertainty Analysis

Comment: Alliance, 2008-0089-0179.1, Pg. 40-41 stated that NHTSA should reevaluate its statistical model on uncertainty. Technology changes are more uncer tain the farther the attempts to peer into the future, yet the uncertainty anal ysis shows 100 percent certa inty that the changes
will be cost beneficial for MY 2014 and 2015.

Agency response: Let us consider the effectiveness of a tech nology as an example. It is true that if you consider each individual technology, that the farther you peer into the future, the more uncertain the results. However, we are looking at a group of technologies, some of which could
be more effective than we curren tly predict and some of which could be less effective than we currently predict. While this final rule is limited to one model year, theoretically, one could assume effectiveness is plus or minus ten percen t in the first year, 15 pe rcent in the second year, 20 percent in third year, etc. That would unn ecessarily complicate the model since we believe that the combined range in the la ter years will be close to the co mbined range in the earlier years
of the standard.

We could simply increase the range symmetrical ly by some arbitrary factor, but, assuming the
same normal distribution that is employed for most of the variable s in our uncertainty analysis, increasing the range of both cost s and benefits proportionally woul d be unlikely to significantly impact the conclusions of the uncertainty analys is. Thus, the agency would not increase this range of uncertainty by progressi vely more for successive model years, were this a multi-yearI-55

rulemaking. As it is not, the issue of changi ng levels of uncertainty over time is largely academic for purposes of this rulemaking.II-1



### II. NEED OF THE NATION TO CONSERVE ENERGY

The Energy Policy and Conservati on Act (EPCA) states that:

“When deciding maximum feasible aver age fuel economy ... the Secretary of Transportation shall consider technologica l feasibility, economic practicability, the
effect of other motor vehi cle standards of the Govern ment on fuel economy, and the need of the United States to conserve energy.” 50

Thus, (EPCA) specifically directs the Departme nt to balance the technological and economic challenges related to fuel economy with the nati on's need to conserve energy. The concerns about energy security and the effects of en ergy prices and supply on national economic wellbeing that led to the enactment of EPCA persist today. The demand for petroleum grew in the U.S. up through the year 2005 and is now declin ing slowly averaging approximately 18.5 million barrels per day in 2007 51 . World demand, however, is expect ed to continue to rise until 2030 52

.

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 over $100 per barrel in August
2008 and in June 2008 reached at over $140 per barrel. As recently as 1998, crude prices averaged about $13 per barrel ($15.85 in 2006 dollars). 53 Gasoline prices have more than doubled during this ten year period. 54

• U.S. domestic oil production peaked in 1970 at 9.7 million barrels per day. Between 1970 and 2006, U.S. domestic production declined by 47 percent, while U.S. petroleum consumption increased by 20 percent. Net petroleum imports now account for 73 percent of U.S. domestic petroleum consumption 55

.

• Worldwide oil demand is fairly inelastic: de clining prices do not induce large increases in consumption, while higher prices do not significantly restrain consumption. For

50 49 USC 32902(f)

51 Energy Information Administration , Petroleum Basic Statistics, August, 2008. See http://www.eia.doe.gov/basics/quickoil.html

52 Energy Information Administration , International Petroleum (Oil) Consumption, August, 2008. See http://www.eia.doe.gov/emeu/international/oilconsumption.html

53 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

54 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

55 Energy Information Administration, Annual Energy Review 2006 , Table 5.1, p. 125. See: http://www.eia.doe.gov/eme u/aer/pdf/pages/sec5_5.pdf 0 2 4 6 8 10 12 14 16 18 20

2000 2001 2002 2003 2004 2005 2006 2007

YearMillion barrels/day

Domestic

Production Imports

TotalII-2

example, the price of unleaded regular gasoli ne rose from an average of $2.59 in 2006 to $2.80 in 2007 (an 8.1 percent increase) and ve hicle miles traveled decreased by 0.6 percent. 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 As ia and worldwide in the future resulting in upward oil cost pressure.

• Foreign oil production facilities , refineries, and supply chains have been disrupted from time to time, either by wars, political acti on by oil producers, civil unrest, or natural
disasters.

• High oil prices, sometimes induced by disruptio ns in oil markets, have often coincided with rising inflation and s ubsequent economic recessions.

• Greenhouse gas emissions from the consumption of petroleum have become a subject of increasing public policy con cern, both in the United States and internationally. Greenhouse gases in general and carbon dioxide in particular have not thus far been subject to national regula tion. Studies by multiple sources suggest that rising atmospheric concentrations of greenhous e gases will damage human health and
welfare. 56 There is a direct linkage between the consumption of fossil energy and emissions of the greenhouse gas carbon dioxi de, as essentially a ll of the carbon in hydrocarbon fuels is oxidized into carbon dioxi de when the fuel is combusted. Reducing U.S. fossil petroleum consumption will ge nerally 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 cons umption of petroleum for transportation. Domestic petroleum production ha s 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 e fficiency has benefits for economic growth and the environment, as well as other bene fits, such as reduci ng pollution and improving security of energy supply. More specificall y, reducing total petroleum use decreases our economy’s vulnerability to oil price shocks . Reducing dependence on oil imports from regions with uncertain conditi ons enhances our energy securi ty and can reduce the flow of oil profits to certain stat es now hostile to the U.S.

56 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). A vailable at http://www.ipcc.ch/

, .II-3

This reformed CAFE final rule encourages c onservation of petroleum for transportation by the application of broader use of fu el saving technologies, resulting in more fuel-efficient vehicles, i.e. vehicles requiring less fu el consumption per unit mile.

Table II-1

Petroleum Production and Supply

(millions of barrels per day) 57

Domestic
Petroleum
Production Net
Petroleum

Imports U.S.
Petroleum

Supply World
Petroleum Consumption Import
Share of

U.S. Supply

1975 8.4 6.1 14.4 52.8 42%
1985 9.0 5.1 14.0 54.0 36%
1995 6.6 8.8 15.4 62.4 57%

2005 5.2 13.7 18.9 84.3 73%

DOE
Predictions

2015 6.2 9.9 16.0 95.7 62%

2025 6.0 10.1 16.1 106.5 63%

2030 5.6 11.0 16.6 112.5 66%

Table II-2

Transportation Consumption by Mode (thousands of barrels per day) 58

Passenger
Cars Light
Trucks Total Light
Vehicles Total Transportation Light
Vehicles as
% of Trans.

1975 4,842 1,087 6,081 8,474 72%
1985 4,665 1,785 6,450 9,552 68%
1995 4,440 2,975 7,415 11,347 65%

2005 5,050 3,840 8,890 13,537 66%

57 “ 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

58 Transportation Energy Data Book, Table 1.14. http://cta.ornl.gov/data/chapter1.shtml

.III-1



### III. ALTERNATIVES

In developing the proposed alternatives for the NPRM, the agency considered the four statutory factors underlying maximum feasibi lity as defined in EPCA (technological feasibility, economic practicability, the effect of othe r standards of the Government on fuel economy, and the need of the nation to conserve energy) as well as other relevant consider ations such as safety. NHTSA assessed what fuel saving tec hnologies would be available, ho w effective they are, and how quickly they could be introduced. This asse ssment considered tec hnological feasibility, economic practicability and associated energy cons ervation. We also cons idered other standards to the extent captured by EPCA 59 and environmental and safety c oncerns. This information was factored into the computer model used by NHTSA for applying technologies to particular vehicle
models.

In developing its proposed standards, the agency used a net benefit-maximizing analysis that placed monetary values on relevant external ities (both energy security and environmental externalities, including the benefits of reductions in CO 2 emissions) and produced what is called the “optimized scenario.” The optimized standards reflect levels such that 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 ne t benefits to assure
that the results made sense in terms of bala ncing EPCA’s statutory factors and in meeting EISA’s requirements for improved fuel economy.

The agency proposed the “Optimized (7%)” alternative. In this alternative the agency used a 7 percent discount rate to value benefits and set the proposed m pg levels where marginal costs equal marginal benefits. It is one of six altern atives examined in the analysis using a 7 percent discount rate. We also examined a second optim ized scenario when discounting benefits at 3 percent “Optimized (3%). In general order of increasing severity (s ee Table 1), the seven
scenarios examined are:

1: “25% Below Optimized”: This alternativ e mirrors the absolute difference in mpg derived from the 25% Above Optimized scenario in goi ng the same mpg amount below the Optimized
7% alternative 2: “Optimized (7%) An increase in the standa rd 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 perc ent 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 alterna tive and picks mpg levels that are 25 percent of
that difference. 4: “50% Above Optimized”: This alternative looks at the mpg levels of the Optimized (7%) and the Total Cost Equals Total Benefit alterna tive and picks mpg levels that are 50 percent of
that difference. 5: “Optimized (3%) An increase in the standa rd 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.

59 71 Fed. Reg. 17566, 17669-70; April 6, 2006.III-2

6: “Total Costs Equal Total Benefits”: An incr ease in the standard to a point where essentially total costs of the technologies adde d equals total benefits. In this analysis, for brevity, at times it
is labeled “TC = TB”. 60 7: “Technology Exhaustion”: An increase in the standard based upon the maximum usage (based on NHTSA’s perspective) of availabl e technologies, disregar ding the cost impacts. 61

Table III-1
NPRM Alternative CAFE Levels Projected Harmonic Average for the Fleet 62 (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

For the final rule, the agency considered the same seven alternatives: When discussing an alternative we provide the di scount rate in parenthesi s afterwards to keep track of which alternative we are discussing. Th ere is one notable difference between the NPRM

60 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 cons ider 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 CO 2

. 61 This was accomplished by determin ing the stringency at which a reform ed standard would require every manufacturer to apply every technology estimated to be po tentially 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 po tential availability of technologies at the individual
manufacturer level.

62 The values represent the higher of the manufacturer’s plans and the alternative level of the standard.III-3

and final rule in terms of discount rate. For al l of the alternatives below, a 3 percent discount
rate is used for the social cost of carbon and th e intergenerational benefits. In general order of increasing severity, the seven scenarios examined are:

1: “25% Below Optimized (7%)”: This alte rnative mirrors the absolute difference in mpg derived from the 25% Above Optimized scenar io in going the same mpg amount below the Optimized 7% alternative 2: “Optimized (7%)”: An incr ease in the standard based upon av ailability of technologies and a marginal cost/benefit analysis. The mpg levels are set using a 7 percent discount rate for
benefits. 3: “25% Above Optimized (7%)”: This altern ative looks at the mpg levels of the Optimized (7%) and the Total Cost Equals Total Benefit (7 %) alternative and picks mpg levels that are 25 percent of that difference. 4: “50% Above Optimized (7%)”: This altern ative looks at the mpg levels of the Optimized (7%) and the Total Cost Equals Total Benefit (7 %) alternative and picks mpg levels that are 50 percent of that difference. 5: “Optimized (3%)”: An increase in the sta ndard based upon availability of technologies and a marginal cost/benefit anal ysis, except that the mpg levels are set using a 3 percent discount rate
for benefits. 6: “Total Costs Equal Total Benefits (7%)”: An increase in the standard to a point where essentially total costs of the tec hnologies added equals total benefits . In this analysis, for brevity, at times it is labeled “TC = TB (7%)”. 7: “Technology Exhaustion (7%)”: An increase in the standard based upon the maximum usage (based on NHTSA’s perspective) of available tec hnologies, disregarding the cost impacts.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 fu el economy standards be
set at the maximum feasible level after ta king into account the fo llowing criteria: (1) technological feasibility, (2) economic practi cability, (3) the impact of other Government Standards on fuel economy, and (4) the need of the Nation to conserve energy. Using MY 2010 as a baseline, or the manufacturers’ plans alr eady provided to NHTSA on specific rulemakings,
this section discusses the effects of other government regulations on model year (MY) 2011 passenger car and light truck fuel economy.

The Impact on Weight of Safety Standa rds 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. Th e 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 manuf acturers’ fleets. NHTSA requested and various manufacturers provided estimates of increases in weight resulting from safety improvements.

We have broken down our analysis of the impact of safety standards that might affect the MY 2011 fleets into three parts: 1) those NHTSA final rule s with known effective dates, 2) proposed rules or soon to be proposed rules by NHTSA, without final effective dates, and 3) currently voluntary safety improvements pl anned by the manufacturers.

Weight Impacts of Required Sa fety Standards (Final Rules) The National Highway Traffic Safety Administ ration (NHTSA) has issued two final rules on safety standards that become effective for passe nger cars and light trucks for MY 2011. These have been analyzed for their potential impact on passenger car and light truck weights, using manufacturers’ voluntary plans as a baseline.

1. FMVSS 126, Electronic Stability Control

2. FMVSS 214, Side Impact Oblique Pole TestIV-2

FMVSS 126, Electronic Stability Control The phase-in schedule for vehicle manufacturers is:

Table IV-1

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

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 manu facturers’ plans for vol untary installation of ESC, 85 percent of passenger cars in MY 2010 would have AB S and 52 percent would have ESC. Thus, the total incremental added wei ght over manufacturers’ plans in MY 2011 for passenger cars would be about 1.8 lbs. (0.10*10. 7 + 0.43*1.8). Light truc ks 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 incr emental weight impacts of adding ESC would be 0.4 lbs. (0.21*1.8) in MY 2011.

FMVSS 214, Oblique Pole Side Impact Test The phase-in requirements for the side impact test are as shown below in Table IV-2:

Table IV-2
FMVSS 214 Final Rule Phase-In Schedule
Phase-in Date Percent of each manufacturer’s li ght vehicles that must comply during the production period September 1, 2010 to August 31, 2011 20 percent (excluding vehicles GVWR > 8,500 lbs.)

September 1, 2011 to August 31, 2012 40 percent vehicles (excluding vehicles GVWR > 8,500 lbs.)

September 1, 2012 to August 31, 2013 60 percent vehicles (excluding vehicles GVWR > 8,500 lbs.)

September 1, 2013 to August 31, 2014 80 percent vehicles (excluding vehicles GVWR > 8,500 lbs.)

On or after September 1, 2014 All vehicles including limited line vehicles, except vehicles with GVWR > 8,500 lbs., alterers, and multi-stage manufacturers
On or after September 1, 2015 All vehicles, including vehicl es with GVWR > 8,500 lbs., excluding alterers and mu lti-stage manufacturers
On or after September 1, 2016 All vehicles, including vehicles with GVWR > 8,500 lbs., alterers and multi-stage manufacturersIV-3

A teardown study of 5 thorax air bags resulted in an average weight incr ease per vehicle of 4.77 pounds (2.17 kg). 63 A second study 64 performed teardowns of 5 window curtain systems. One of the window curtain systems was very hea vy (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.

Based on manufacturers’ plans to voluntarily provide window cu rtains and torso bags, we estimate that 90 percent of passe nger cars and light trucks would have window curtains for MY 2010 and 72 percent would have torso bags. A ve ry similar percentage is estimated for MY 2011. Thus, the final rule requiring 20 percent comp liance is not likely to impact manufacturers’ weights in MY 2011.

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 weight 65 . 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. A Supplemental NPRM was published by the agency in January 2008, asking for public comment on a number of issues that may a ffect the content of the final rule, including possible variations in the proposed requirements. In the PRIA, the average passenger car weight was estimated to increase by 4.0 pounds and the av erage 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 likel y to increase. However, the agency does not yet have an estimate for the final rule. Regardless, the final rule will not be effective for MY 2011
vehicles.

Planned NHTSA initiative on Ejection Mitigation The agency is planning on issu ing a proposal on ejection mitiga tion. The likely result of the planned proposal is for window curtain side air bags (likely to be used to meet the FMVSS 214 oblique pole test in all vehicles) to be larger and for a rollove r sensor to be installed. Preliminary agency estimates are that current curtain bags need be widened by 28% to fully cover the window opening area. According to a cost & weight analysis ( DOT HS 809 842), head air bags (loomed cloth) installed in a vehicle weigh 2.59 lbs and the inflators weigh 4.73 lbs. Thus, the incremental weight would be about 2 lbs. (2.59 lbs + 4.73 lbs) x 0.28 = 2 lbs. However, this analysis is not complete at this time and will not be effective fo r MY 2011 vehicles.

Summary – Overview of An ticipated Weight Increases

63 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.

64 Ludtke & Associates, “Perform Cost and Weight Analysis, Head Protection Air Bag Systems, FMVSS 201”, page 4-3 to 4-5, DOT HS 809 842.

65 See 70 FR 53753, the PRIA is in Docket No. 22143, en try #2 “Preliminary Regulatory Impact Analysis, FMVSS 216, Roof Crush Resistance,” August 2005.IV-4

Table IV-3 summarizes estimates made by NHT SA regarding the weight added by the above discussed standards or likely rulemakings. NHT SA estimates that weight additions required by final rules and likely NHTSA regulations effec tive in MY 2011, compared to the MY 2010 fleet and manufacturers’ plans, will increase passenger car weight by at least 10.4 lbs. and light truck weight by at least 10.6 lbs.

Table IV-3

NHTSA Estimates of Weight Additions Due to Final Rules or Likely NHTSA Regulations for MY 2011 Compared to Manufacturers’ Plans

Standard 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 – ESC 1.8 0.8 0.4 0.2

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. T hus, the agency’s estimate of the safety/weight effects for cars is 0.006 mpg or less and for light tr ucks is 0.001 mpg or less 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 a bout fuel economy plans and capabilities for the future, the agency also requested information on we ight increases that could occur due to safety improvements. Several manufact urers provided confidential inform ation about plans they had to meet final rules, proposed safety standards, or to voluntarily increase safety for the years 2011- 2015. Several of these plans were to meet IIHS offset fr ontal and side impact testing. Most of these improvements will be installed on vehicles by MY 2011. [ ] The areas covered above and the regu latory areas described as fina l, proposed, and voluntary safety
initiatives from manufacturers that have confid ential increases for the period after MY 2010 are shown in the following tables.IV-5

[ Table IV-4
Confidential Submissions of Weight Impacts After MY 2010

Ford
Car MY Light Truck MY

Final Rules20112012201320142015

Total20112012201320142015

Total

126 ESC
214 Side Impact

Total Final Rule

Increments
Proposed Rules

216 Roof Crush

226 Ejection Mitigation

Total Proposed Rule
Increments

Voluntary and Other
Rules

202a Head Restraints

TBD Ped. Protection

TBD Public Domain ratings (TBD for finer details) EDR part 563 N/A Voluntary

N/A Other

Total Voluntary and
Other Rule Increments
Total by YearIV-6

Chrysler
Car MY Light Truck MY

Final Rules20112012201320142015

Total20112012201320142015

Total

126 ESC
214 Side Impact

Total Final Rule

Increments
Proposed Rules

216 Roof Crush

226 Ejection Mitigation

Total Proposed Rule
Increments

Voluntary and Other
Rules

202a Head Restraints

TBD Ped. Protection

TBD Public Domain ratings (TBD for finer details) EDR part 563 N/A Voluntary

N/A Other

Total Voluntary and
Other Rule Increments
Total by YearIV-7

GM
Car MY Light Truck MY

Final Rules20112012201320142015

Total20112012201320142015

Total

126 ESC
214 Side Impact

Total Final Rule

Increments
Proposed Rules

216 Roof Crush

226 Ejection Mitigation

Total Proposed Rule
Increments

Voluntary and Other
Rules

202a Head Restraints

TBD Ped. Protection

TBD Public Domain ratings (TBD for finer details) EDR part 563 N/A Voluntary

N/A Other

Total Voluntary and
Other Rule Increments
Total by Year

]IV-8

Vehicle Weight, Size and Safety For many years there has been a controversy over th e effect of vehicle si ze and weight on vehicle safety. With each fuel economy rulemaking, the debate continues. The following discussion provides NHTSA’s point of view, the most se rious comments on the issue, and NHTSA’s response to those comments.

NHTSA believes that an attribute based Reform ed CAFE system removes the incentive to
downsize that is inherent in the traditiona l 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 bei ng equal, smaller vehicles provide less protection to their occupants in the event of a crash because there is less ve hicle mass to absorb the crash energy and less interior space to buffer occupant s 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. When you h it a tree, more weight helps you knock that tree down and reduce your delta V, and more interior space allows you to ride down the crash safer. In multi-vehicle crashes, both individual vehi cle size and the relative size of the involved vehicles play a role in determining the injury outcome of occupants of both vehicles. Generally, larger vehicles will provide better protection, but often at the expense of occupants of smaller vehicles. If larger vehicles were to be redu ced in size, it would likel y decrease the chance of injury in crashes with smaller vehicles, but it w ould also likely increase the chance of injury for the occupants of the larger vehicles. The makeup of any future mix-shifts in vehicle sales ispurely speculative and the overall impact on injuries in multi-vehicle crashes of any future mixshifts in vehicle size is unknown. However, downsizing is likely to increase the crash risk for vehicle occupants in single vehicle crashes, wh ich make up 30% of all crashes and 57% of all fatalities. An attribute based system will requi re improvements in fuel economy for all vehicle sizes, and will thus minimize incentives to downsize vehicles. There may be other incentives for consumers to demand smaller vehicles (for exampl e, an increase in the price of gasoline), but
those external factors would not be influenced by the fi nal rule structure.

We would like to clarify that our analysis does not mandate we ight reduction, or any specific technology application for that matter. Our anal ysis relied exclusivel y 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 co mply with the fuel economy levels without the need for what NHT SA believes are potentia lly unsafe compliance

measures.

We first present a recent historical perspective of the debate: The NAS study (2002) The 2002 National Academy of Sciences (NAS) 66 report made explicit links between weight and vehicle safety. The NAS study conclusions we re divided, with 11 of 13 committee members

66 “ Effectiveness and Impact of Corp orate Average Fuel Economy (CAFE) Standards”, National Research Council, 2002. The link for the NAS report is http://www.nap.edu/books/0309076013/html/IV-9

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 a nd 26,000 serious injuries in 1993. The proportion of these
casualties attributable to CAFE standards is uncer tain. It is not clear that significant weight
reduction can be achieved in the future withou t some downsizing, and similar downsizing would be expected to produce similar results. Ev en if weight reduction occurred without any downsizing, casualties would be expe cted to increase. Thus, any increase in CAFE as currently structured could produce additiona l road casualties, unless it is specifically targeted at the largest, heaviest light trucks.” ... “Some might argue that this impr oving safety picture means that there is room to improve fuel economy without adverse safety consequences. Ho wever, 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 wei ght 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 improve the safety of vehicles of all sizes does not mean that downsizing to achieve fuel ec onomy 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 sm all cars, some additional traffic fatalities would be expected. Without a thoughtful restructuring of the program, th at would be the trade-off that must be made
if CAFE standards are increas ed 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 certain ty 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 importa nt safety issue. Safety benefits should be possible if the weight distri bution of light-duty vehicles could be made more uniform, and economic gains might result from ev en partly correcting th e negative externality that encourages individuals to tr ansfer safety risks to others by buying ever larger and heavier
vehicles. Finally, it appears that in certain kinds of acci dents, reducing weight will increase safety risk, while in others it may reduce it. Reducing the weights of light-dut y vehicles will neither benefit nor harm all highway users, there will be winners and losers....”

The Kahane Study (NHTSA - 2003) The Kahane study 67 estimates the effect of 100-pound reducti ons 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 be tween vehicle types, given drivers of the same

67 “Vehicle Weight, Fatality Risk and Crash Compatib ility of Model Year 1991-99 Passenger Cars and Light Trucks”, Charles J. Kahane, Ph. D., NHTSA, October 2003, DOT HS 809-662.IV-10

age/gender, etc. In this analysis , the effect of “weight reduction” is not limited to the effect of

mass per se but includes all the factors that were na turally or historically confounded with mass in 1991-1999 cars, such as length, width, stru ctural strength and si ze of the occupant compartment. The rationale here is that when you add length, width or strength to a car, you will also make it heavier. The one exception could be a sweeping replacement of existing materials with light, high-strength components. But when you are looking at historical data – at cars of a certain era (namely, 1991-1999), they tend to be bu ilt in similar ways, and there is essentially a continuum from lighter and smaller cars to heavier, bigger and stronger cars.

Some of its findings are: “Heavy vehicles had lower fatal ity rates per billion miles of travel than lighter vehicles of the same general type. When two vehicles coll ide, the laws of physics favor the occupants on the heavier vehicle (momentum conservation). Furt hermore, 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 directio nal stability. They were less rollover-prone and easier for the average driv er 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 th e laws of physics, but were neve rtheless characteristic of the MY 1991-99 fleet. Offsetting those a dvantages, heavier vehicles tende d 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-vehicl e crashes with heavy truck, light trucks, and passenger cars). Summing all these crash mode s together, the net a nnual 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 fatali ties increased with a reduction in wei ght. However, further analysis of the Kahane study found that the ne t safety effect of removing 100 pounds from a light truck is zero for the group of all light trucks with a cu rb weight greater than 3,900 lbs. 68 Given the significant statistical uncertainty around that figure, we determin ed that there is a crossover weight, which occurs somewhere between 4,264 and 6,121 pounds, with a point estimate at 5,085 pounds, above which there is no safety pena lty for reducing vehicle weight. This is
because the added harm for other road users from the additional weight exceeds any benefits for the occupants of the vehicles. NHTSA embodi ed this finding in its CAFE rulemaking by restricting materials substitution in its developmen t of stringency levels to vehicles over 5,000 pounds and used 5,000 lbs. as the threshold for cons idering weight reducti on of specific models

. In the MY 2008-2011 light truck final rule, NHT SA included weight reduction as a fuel improving technology for light trucks over 5,000 lbs. curb weight where we determined that

68 Kahane, Charles J., PhD, Vehicle Weight, Fatality Ri sk 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)IV-11

weight reduction would not reduce overall safety and would be a cost-effective choice. We are applying the same methodology in this final rule , weight reduction is considered a technology that can be applied to light truc ks over 5,000 lbs. curb weight.

The agency believes a number of conclu sions can be drawn from these studies:

• Heavier vehicles are more cr ashworthy and less crash prone. 69

• The net impacts on safety, considering the six different crash modes, of reducing weight are negative for all but the larg er light trucks. However, th is type of analysis can not examine extreme cases. For example, if th ere 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 manuf acturer’s plans suggests a dr astic change in the mix of vehicles, nor is there any incentive, in our opinion, for such a change based on NHTSA’s
attribute based final rule 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 almo st split between rollovers (29 percent) and fixed or non-fixed objects (28 percent).

• Reducing weight increases the likelihood of ro lling over. When you are sliding sideways and digging into mud or grass or hit a curb, a ll things being equal, the lighter vehicle is more prone to rolling over. Increasing track width (part of the f ootprint calculation) reduces the likelihood of rolling over. Track width is more important than weight for rollovers. Rollover is the only area in which track width is the most important factor. Weight is more important than track width or wheelbase in the other five crash modes investigated. 70

• Reducing weight increases the likelihood of being killed in a fixed or non-fixed object crash. If you run into a tree, you are safe r if you knock that tree down than if the tree stops your vehicle. A heavier vehicle has a better chance of knocki ng the tree down.

The Kahane report also examined the total fatal ity 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:

69 See Kahane study, page xiv Table 3 for prorated fatal crash involvements per billion miles.

70 See Kahane (Docket No. 2003-16318-16)IV-12

TABLE IV-5

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 lowe r societal fatal crash rates than SUVs that weighed considerably more. Large cars and minivans had the lowest rates.

The DRI Studies (2003, 2004, 2005) Honda sponsored DRI to complete several reports, which it asserted dem onstrated that limited weight reductions would not reduce safety and c ould possibly decrease overall fatalities. Honda stated that the 2003 study by DR I found that reducing weight without reducing size slightly decreased fatalities, and that this was confirmed in a 2004 study by DRI 71 that assessed new data and methodology changes in the 2003 Kahane Study. Honda asserted that the DRI results tend to confirm “that curb weight reducti on would be expected to decrease the overall number of
fatalities.”

DRI submitted an additional st udy, 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 footpr int 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 in fluence than track width or wheelbase on the fatality risk of pass enger cars in non-rollover crashes.

71 See Docket Nos. 2003-16318-2, 2003-16318-3, 2003-16318-7, and 2003-16318-17.IV-13

NHTSA disagrees with the numerical findings of the DRI reports on the safety effects of mass, track width and wheelbase. As a consequence, we also cannot endorse the inferences by Honda and others, based on those reports, that mass reduc tions in small cars are harmless as long as we
maintain wheelbase and track width or even as long as we limit the reductions to material substitution (although we agree those seem to be the least harmful ways to lose mass).

DRI has over the years issued variou s analyses of historic fatal cras h rates with thr ee measures of cars size – curb weight, track widt h and wheelbase – treated as if they were three independent
variables. 72 In general, the results are that re ductions in track widt h and wheelbase are associated with substantial increases in fatal crash risk, whereas reduction in mass per se , if track
width and wheelbase are held consta nt, is associated with reducti ons in risk. Based in part on these analyses, Honda and various others have inferred that future mass reductions, while track width and wheelbase remained unchanged – by substi tuting lighter materials of equal strength or by other means – would apparently benefit safety. 73

NHTSA is generally skeptical of analyses that include mass, track width and wheelbase as separate independent variables. Although it is true that, for any given curb weight, there may be
some variations in the track widths and wheelba ses of make-models at th at curb weight, these variations are not, as it were, random but are us ually confounded with other factors such as the vehicle’s design or market class. Specifically, sporty 2-door coupes such as Ford Mustang and Chevrolet Camaro have exceptionally short wheelbase for their mass. They also have exceptionally high fatal crash rates. Inclusion of sporty 2-door c oupes in the analysis produces a finding that higher wheelbase increases safety bu t higher mass decreases safety. These findings are spurious unless you sincerely believe either: (a) the high fa tality rates of Mustang and
Camaro are due to their short wheelbases and ha ve nothing to do with their drivers’ speeding, drinking and risk-taking – or (b) it is the short wheelbases of Mu stangs and Camaros that impels their drivers to drink, speed a nd take risks, and if you transp lanted these drivers to Grand Marquis and LeSabres they would b ecome safe, prudent, and sober.

Therefore, NHTSA restated in its response to public comments 74 on its 2003 weight-safety report that it is imperative that analyses be limited to a set of make-models that do not vary greatly in style and market class, but rath er represent a gradually varying continuum of lighter to heavier cars used for similar purposes – namely, 4-door se dans or station wagons excluding police cars.

In their most recent, 2005 analysis, DRI agreed , at least for comparison purposes, to limit some of their analyses to 4-do or cars excluding police cars. 75 DRI further claimed that they could now mimic NHTSA’s logistic regression approach fo r an analysis of MY 1991-1998 4-door cars in CY 1995-1999 crashes. DRI claimed this new analys is still showed results directionally similar
to their earlier work – increased risk for lower track width and wheelbase, reduced risk for lower mass – although the wheelbase and mass effects were no longer statistically significant after removing the 2-door cars from the analysis.

72 Docket No. NHTSA-2003-16318-7, Docket No. NHTSA-2003-16318-17.

73 http://www.arb.ca.gov/cc/ccms/meetings/0 42108/4_21_current_techn_4_german.pdf

74 Docket No. NHTSA-2003-16318-16.

75 Docket No. NHTSA-2003-16318-17.IV-14



### The actual numbers – DRI vs. NHTSA

In MY 1991-1998, the average car weighing N+1 00 pounds had .34 inches larger track width and 1.01 inches longer wheelbase than the average car weighing N pounds. Thus, you might say the “typical” or “historical” 100-pound weight reduction would have been accompanied by a .34 inch track-width reduction and a 1.01 inch wheelbase reduction. But if you disassociate these three measures and treat them as independent parameters, DRI’s logist ic regression of MY 1991- 1998 4-door cars excluding poli ce cars attributes the following effects:

DRI Reduce mass by 100 pounds 379 fewer fatalities Reduce track width by .34 inches 1000 more fatalities Reduce wheelbase by 1.01 inches 207 more fatalities Reduce mass by 100 lb., track by .34” and WB by 1.01” 828 more fatalities

Now, DRI may claim to have mimicked our databa se and analysis method, but clearly their data are not the same as NHTSA’s or their analysis is not the same. Because if you apply NHTSA’s logisitic regression analyses to NHTSA’s database , exactly as described in the agency’s response to comments on its 2003 report, 76 except for limiting the data to MY 1991-1998 (instead of 1991-1999), just as DRI did, the eff ects are not at all like DRI’s:

NHTSA Reduce mass by 100 pounds 485 more fatalities Reduce track width by .34 inches 334 more fatalities Reduce wheelbase by 1.01 inches 9 more fatalities Reduce mass by 100 lb., track by .34” and WB by 1.01” 828 more fatalities

That is the principal reason we cannot accept DRI’s results or the inferences that Honda or anybody else makes from DRI’s results: we get quite different results when we apply our analysis to our database, even when we make the analysis as similar to DRI’s as possible. DRI may have tried to mimic our results, but th ey’re obviously doing something differently.

Intuitively, weight reductions th at (1) hold track width and wheel base constant and (2) are the
result of materials substitution are likely to be less harmful to sa fety than other types of weight reductions. But because we disagree with DRI’s numerical results, we cannot conclude at this point that such weight reductions would be intrinsically harmless, let alone beneficial, if applied
to small cars.

Even though our analyses continue to attribute a much larger effect for mass than for track width or wheelbase in small cars, we still do not claim that mass per se is the “magic bullet”
that increases or decreases fa tality risk in non-rollover cras hes. There might not be any single magic bullet, but rather mass and a variety of other factors histor ically correlated with mass. The importance of our analyses is th at they do not corroborate the “easy way out” offered by DRI: that track width and wheelbase explain the entire size-safety effect and then some, and that mass can be reduced without any harm and maybe even with a benefit. Our

76 Docket No. NHTSA-2003-16318-16.IV-15

results show, until we have a better understanding of all the size-related factors that affect safety, we cannot assume that mass reductions in small cars are harmless as long as we
maintain wheelbase and track width or even as long as we limit the reductions to material substitution (although we agree those seem to be the least harmful ways to lose mass).

While NHTSA agrees that limited weight reduction to heavier vehi cles will not reduce safety, we disagree with DRI’s overall conclusion, cited by Honda, that weight re ductions while holding footprint constant would significan tly benefit safety in lighter ve hicles. NHTSA’s analyses of the relationships between fata lity risk, mass, track width and wheelbase in 4-door 1991-1999 passenger cars (Docket No. 2003-16318-16) found a st rong relationship betw een track width and the rollover fatality ra te, but only a modest (although signi ficant) relationship between track width and fatality rate in non-ro llover crashes. Even controllin g 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 rate s in the NHTSA analysis. By contrast, the DRI study of May 20, 2005 analyzed 4-door cars and f ound a strong relationship between track width and fatality risk, and non-signi ficant 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.

The agency continues to believe that weight reduction in lighter vehicles would reduce safety. However, we also believe that weight reducti ons 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 footpr int 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 th at weight is unimportant coul d only be true for material substitution, because under present circumstan ce weight reduction usually also means size reduction, and DRI agrees with NHTSA that a re duction in footprint is harmful to safety.

Important Comments to Previous Dockets General Motors (Docket No. 2005-22223-1493) and the Alliance (Docket No. 2005-22223-1642) were more explicit in their concerns over the safe ty 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 coun terparts with equivale nt safety designs and equipment. General Motors agreed that impr ovements in material st rength, flexibility, and vehicle design have helped improve overall vehi cle 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 inten tionally 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 conclusi on is inconsistent with the sensitivity analysisIV-16

performed by William E. Wecker Associates, Inc. 77 and submitted to the ANPRM docket.
General Motors stated that the inflection point on the Wecker re port’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.

Additionally, General Motors stated that the NP RM did not acknowledge or respond to the main point of the Wecker report, which was that Dr . Kahane’s “analysis al one does not support the proposition that a crossover wei ght 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 th e 5,085 lbs. crossover weight (where the safety
effect of mass reduction in a ve hicle weighing exactly 5,085 lbs., is zero) with the breakeven point, 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 pe rfectly accurate, we would be c onfident that weight reductions in vehicles down to 3,900 pounds would not result in net harm to safety. However, there is considerable uncertainty about th e crossover weight and also the breakeven point. Therefore, in our analysis, we limited weight reduction to ve hicles with a curb weight greater than 5,000 pounds. We believe that the 5,000 lbs. limit is suffici ent so that we can be confident that such weight reductions will not have net harm on safety.

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 disaggreg ated, “weight reductions without corresponding reductions in vehicle wheelba se length and track widt h could be expected to produce net benefits in reducing occupant crash ri sks.” This is essentially the DRI argument.

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 accoun ts for 29 percent of all light vehicle occupant traffic fataliti es. Track width is one of the tw o vehicle properties that define Static Stability Factor (SSF). SSF was used as a single predominant fact or 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 al so factors in a road maneuver test. Wheelbase
does not have a direct effect on rollover resist ance. However, there are hypotheses that an
increase in wheelbase could reduc e loss-of-control crashes by maki ng the vehicle react slower in yaw and thereby reduce the number of single-vehi cle pavement departure crashes that produce most rollovers. Currently, the agency does not have any data to substantiate this theory. 78

Environmental Defense (Docket No. 2005-22223-1805) commented that by limiting the use of weight reduction to heavier vehicles, the agen cy disregarded the like lihood that manufacturers would rely on weight reduction in smaller, li ghter vehicles. Environmental Defense suggested that the improved baselines should refl ect this weight reduction strategy.

77 Docket No. 2003-16128-1112

78 See Kahane (Docket No. 2003-16318-16)IV-17

Environmental Defense asserted that weight reduction is am ong the most common and costeffective options available to manufacturers fo r improving vehicle fuel economy across the light
truck fleet. Environmental De fense referenced estimates pres ented in DeCicco (2005) that suggest that the cost per pound of weight reduced through us e of high-strength steel and advanced engineering techniques ha s been as low as, or lower th an, 31 cents per pound reduced.

Moreover, Environmental Defense stated, the ex clusion of mass reduction in NHTSA’s analysis bears no relation to what will actually ha ppen in the marketplace when standards are implemented. Environmental Defense argued that absent safety regulations prohibiting the use of mass reductions, manufacturers are likely to choos e this compliance alternative in vehicles of all weights as a cost-effective way to comply w ith CAFE. Environmental Defense stated that NHTSA should consider the poten tial 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 co mpliance alternative for all light vehicles. However, one of NHTSA’s considerations in setting fuel economy st andards is to set standards that will not force the manufacturers to reduce safety. The standard s set by the agency are those capable of being achieved by the manufacturers without the need to re duce safety. If the agency were to consider weight reduction as a compliance option, we are concerned that th e resulting increased stringency would force uns afe 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 Live s: Increasing Fuel Economy Without Sacrificing Safety.” 79 NHTSA agrees with two of th e three ICCT report findings. We agree that fuel economy technologies exist that don’t aff ect safety. We agree that redu cing weight (on vehicles over 5, 000 lbs) can make certain vehicl es less aggressive and reduce their weight and probably improve safety. Many, but not all of th e 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 comp romising functionality”. We continue to believe, until someone demonstrates to the cont rary with some kind of rigorous, scientific analysis, that reducing weight on smaller lighter ve hicles 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 an d Pickup Trucks of Traffic Safety”, Michelle J. White, University of California San Diego, Journal of Law and Econo mics, 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 invo lve deaths of car occupants, pedestrians, bicyclists, or motorcyclists.”

79 See www.theicct.org/documents/ICCT_Sipping FuelFull_2007.pdfIV-18

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 occurred. However, it does not control for VMT (likelihoo d of a crash given a mile of dr iving). Furthermore, the study does not address the safety of big cars vs. sma ll 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 – “T he Fatality Risks of S ports Utility Vehicles, Vans, and Pickups Relative to Cars”, Ted Gayer, Georgetown Universit y, The Journal of Risk and Uncertainty, 28-2, 103-133, 2004. This study finds that “Using a cross-se ctional 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 po se substantially dominates the risk from cars. Indeed a world of light trucks would lead to th ree 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. Kaha ne’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. Th e table above from the Kahane study does not show light trucks having substantially higher fatality rates than pass enger cars.

A 2001 study by Dr. Leonard Evans, 80 modeled the risk of driver fa tality in car 1 in a head-on collision with car 2. The equations in the report indicate that reducing th e curb weight of car 1
would increase the risk to the driver of car 1, while reducing th e curb weight of car 2 would
decrease the risk to the driver of car 1. Howeve r, the equations also in dicate that reducing the
wheelbase of either car increases the total risk to both drivers.

In a 2004 SAE paper, Dr. Evans claimed that incr easing the amount of light weight materials in vehicle design can provide reduced occupant risk both in two-vehicle and single-vehicle crashes,
and also reduce risk for o ccupants in other vehicles 81 . However, he produced no analysis using real world data of vehicles with lightwei ght material to substantiate that claim 82

.

In an amicus brief, the Insura nce Institute for Highway Safety 83 stated “Crash safety should be a
consideration in how the balance is struck be tween programs to improve air quality and our efforts to protect people in cras hes. Physics dictates that ve hicle weight and size will always matter in a crash. Research in the private, public, and nonprofit sectors have demonstrated the

80 Evans, L., “Causal Influence of Car Mass and Size on Driver Fa tality Risk”, American Journal of Public Health, Vol. 91, No

. 7, July 2001, pp 1076-1081.

81 Evans, L., “How to make a car lighter and safer,” SAE 2004-01-1 172, Society of Automotive Engineers, 11
March 2004.

82 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.

83 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-19

relationship between vehicle si ze and weight and crash injuri es. Simply put, Vermont’s regulation encourages production of smaller, lighter vehicles which will lead to increased traffic
fatalities.” IIHS discusses re search by NHTSA and IIHS that ha ve 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.” IIH S calculated the vehicle death rates by make model using driver deaths pe r million registered vehicle years, presented this data, and ranked them. “None of the 15 vehicles w ith the lowest driver d eath 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 patte rn is unmistakable. There is an inverse relationship between driver death ra tes and vehicle size...”

Comments to the NPRM Docket In this section we present and discuss th e comments to the NPRM Docket (2008-0089).

Comment: Insurance Institute for Highway Safety (IIHS) 2008-0089-220.1, P1-2 IIHS was concerned that a manufacturer may incr ease footprint rather than add technology, or they could reduce mass, while keeping same footpr int. The use of vehicl e footprint will mitigate much of the potential for automakers to downw eight or downsize vehicles to improve fuel economy and, hence, will help maintain the safety be nefits associated with those attributes. IIHS believe that weight is a better discriminator (m ore direct approach) th an footprint and that reducing vehicle mass typically reduces crashw orthiness. Automakers could use lighter materials, maintaining the same size and struct ural performance, thus limiting the safety

consequences.

Agency Response: We agree with most of IIHS’s statements except that we believe footprint is a
better attribute than we ight for setting the MY 2011 CAFE standards.

Comment: Air Resources Board , (2008-0089-0173), pp 6-7
The Air Resource Board state that NHTSA shoul d expand the use of weight reductions to vehicles under 5,000 pounds. They were struck by apparent dichotom y between adopting size attribute to promote vehicle safety, but yet re strict weight reducti on to vehicles under 5,000 pounds. NHTSA relies on the Kahane study (which assumes that weight and size are completely correlated), but ignores more recent studies by Dynamic Research Inc. that have shown otherwise. Pg. 2 - Expert report by David Greene (Ahmad and Greene 2005) concludes that there has been no relationship between fuel econo my and traffic fatalitie s and there should be
none in the future.

Agency Response: The relationship is entirely too comple x to examine by a macro analysis as was completed by Ahmad and Greene. This re port is a long-term (1966-2002) time-series analysis of the annual number of crash fatalities in the United States, the average fuel economy
of the vehicles on the road that year, and some other factors such as the price of fuel, the national speed limit, population, and annual vehicle miles tr aveled. The conclusion is that national fatalities did not increase, in fact tended to decrease, from the early 1970s forward, while fuel economy improved. Therefore, fuel economy has not had an adverse effect on safety. Suffice it to say that this is an exceed ingly “macro” level to examine the relationships between fuelIV-20

economy and fatality risk. Long-term time-series an alyses are unlikely to se parate the effects of downsizing for the other demographic, economic, and technological trends that have had an impact on fatality rates over the period. For inst ance, seat belt use has risen from 14 percent to 82 percent, many life-saving safety features ( e.g. , front and side airbags) have been added to vehicles, impaired driving is not as accepted, and so forth. It is general knowledge that traffic fatalities are now lower than 1970, primarily as a result of the major safety advances just mentioned. But the relevant question in the sa fety/fuel economy context is, “Would fatalities
have been even lower if cars had not been downs ized?” To analyze that relationship accurately, it would be necessary to compare the fatality risk of small and large vehicles , not just the trend in total fatalities, over this long period.

. Comment: P3, States that Kahane’s finding that the increase in single vehicle crashes and rollover crashes was surprising and there was no cl ear and compelling scien tific law that would predict that result.

Agency Response: There is a compelling logical example to explain the results. In a single vehicle crash, you’d rather knock a tree down than be stopped by the tree. More weight helps you knock the tree down. Lighter cars roll over at a much higher rate than heavier cars. It is easier for a lighter car to be tripped and roll over.

Comment: P3, Examined NHTSA frontal crash test data and found no correlation between vehicle weight and occupant protection.

Agency Response: Frontal crash test data is the wrong data to analyze for this comparison,
because the vehicle strikes a ri gid barrier, which is like a vehicle striking its own twin.

Comment: P3, Examined NHTSA data on rollover propensity and found that rollover risk increased with weight. This is entirely due to a greater propensity for light trucks to roll over. For passenger cars, there was no correlation be tween rollover propensity and weight, the same held within class of light trucks. This led them to suspect that it was not the vehicles themselves, but the drivers and the environment in which they were operated.

Agency Response: The Kahane study shows a direct co rrelation between size/weight of passenger cars and rollover propens ity. Smaller cars rollover mu ch more frequently. Kahane’s study specifically controlled by the driver and environm ent characteristics.

Comment: Greene reiterates a principal argument from his dissent to the 2002 NAS report, namely that mass per se , intuitively, should not have any safe ty effect other than on the relative
risk of two vehicles that coll ide with each other. Therefore, all the empirical data showing higher fatality rates for lighter vehicles in si ngle-vehicle crashes and elsewhere are due to something other than mass. Therefore, we may reduce mass without harming safety.

Agency response: Although mass per se, strictly speaking, may have little direct causal effect on fatality risk in most types of crashes, there are many other parameters that are naturally and historically highly correla ted with mass, such as size, rigi dity, structural integrity, and the driver’s perception of maneuverabil ity, that affect the frequency a nd severity of crashes. Unless we can determine exactly what these paramete rs are and demonstrate ways to reduce massIV-21

without affecting any of these other parameters , we cannot simply ignore the empirical data showing higher fatality ra tes for lighter vehicles.

.

Comment : The Wenzel/Ross studies show that fatality risk has less to do w ith a vehicle’s weight than with the type of drivers who choose that ve hicle. Luxury imports have low fatality risk because they have good drivers, etc.

Agency response: See our critique of the Wenzel/Ross st udy in our response to public comments on the 2003 report. Specifically, the analysis di d not control for driver age/gender and other factors such as urbanization and region of the c ountry. After controlling for these, most of the difference between luxury cars a nd other cars disappears.

Comment: Noland and Ahmad/Greene’s long-term (1966- 2002) time-series analyses show little correlation between downsizing and trends in fata lities. The roads are safer now than in 1966, despite downsizing during the 1970s.

Agency response: Long-term time-series analyses are unl ikely to tease out the effect of downsizing from the numerous other demographic, economic and technological trends that have an impact on fatality rates.

Comment: Alliance, 2008-0089-0179.1 P10 Weight and safety are correla ted, as NHTSA has recognized.

Comment: Lawrence Berkley National Laboratory (2008-0089-0194.1) pp. 4-7, 9 They disagree with NHTSA that larger or heavier vehicles are inherently safer than smaller or lighter vehicles. Kahane’s analysis has flaw s. Through careful design and material substitution,
vehicle mass can be reduced w ithout compromising safety. The risk to persons other than the driver imposed by crossover SUVs decreases as size increases.
There is no consistent relationshi p between driver fatality risk and car size for frontal crashes with another car or object. The additional protec tion that size provides to drivers of light trucks comes at a cost to the drivers of the cars they cr ash into. Driving behavior tends to be worse in subcompact and compact cars, which tends to overstat e the fatality risk in smaller cars. There is no strong relationship between vehicle mass and fatal ity risk to drivers in a front crash with an object. They also argue that Ka hane’s regression analysis w ould likely change if updated to today’s vehicles, due to advances in safety devices such as ESC and the increased prevalence of

crossover SUVs.

Agency response: The commenter provides and opinion with no analysis to back it up. We don’t believe they are considering the big pictur e – fatality increase comes from single vehicle and rollover crashes, or the incremental picture – ESC affects everyone and doesn’t discriminate by weight, and lighter crossovers will be less safe than heavier crossovers.

Comment: Mercatus Center ( 2008-0089-0216.1) Mercatus argues that NHTSA has not fully accounted for the decline in vehicle safety as a result of implementing fuel saving technologies, such as lighter vehicles that could result in higher death and injury rates.IV-22

Agency response: We believe that manufacturers can m eet the CAFE requirements without making lighter vehicles, however nothing prevents them from doing so. It would be impossible for us to predict how the manufacturers might react to our requirements and market forces, thus we would have no confidence in a prediction that tr ied to account for a decline in safety.

Comment: Center for Biological Diversity (2008-0089-0222.1), pp. 12 NHTSA misrepresented the 2002 NAS findings. NHTSA fails to consider th e potential benefits of lower vehicle weight. NAS found that weight reduction fo r vehicles over 4,000 lbs would result in a safety benefit.

Agency response: We have updated the Kahane report a nd the 4,000 lbs., which is what the NAS findings were based upon. See the pr evious discussion about 5,000 lbs.

Comment: Sierra Club (2008-0089-0226.1), pp. 3, 13-15 NHTSA’s analysis of the relationship between ve hicle weight and safety is flawed. NHTSA should revise its policy position on the weight/safet y issue to take into account new materials and vehicle design options that can impr ove safety while reducing weight. The industry is already demonstrating that weight reduction is a safe and effective strategy for improving fuel economy. The disparity in weight s of vehicles is much more important to occupant safety than the average weight of ve hicles. Specific design features play a more important role than weight. The disparity in vehicle weight has decreased dramatically, eliminating the most severe weight disparity crashes. NHTSA has not taken into account improvements in structural integrity and safe ty technology, such as light-weight high-strength materials. William Haddon said size is more importa nt than weight for safety. The safety of small cars continues to improve. NHTSA recognizes the retrospective nature of the Kahane study yet continues to use it to c onstraint future fuel economy.

Agency response: They provide no proof that their theory is correct. We have discussed all of
these issues above.



### Comment: Aluminum Association of America (2008-0089-184)

NHTSA’s weight-safety study was re trospective, looking at 1990s ve hicles, and not predictive. In the future, there could be ex tensive use of new materials, ne w designs enabled by the use of these materials, and new crash-avoidance technologi es that will change the distribution of crash
types.

Agency response: We agree this study is based on a group of vehicles manufactured from similar materials (steel), where weight was highly correlated with si ze and structural strength. Relationships might conceivably be different in a future fleet where a wide variety of materials is used to build cars. We should caution, though, that the use of new materials is still at an early stage and will be for some years. NHTSA also agrees that, intuitively, substitution of strong, lightweight materials would be a less harmful to down-weight than reducing the size of the vehicles. But there is not yet sufficient eviden ce to conclude that material substitution is harmless, let alone beneficial to safety.IV-23



### Comment: Public Citizen (2008-0089-0187)

NHTSA’s 2003 study obfuscates findings which show that reducing weight from only the heaviest vehicles actually improves safety and overlooks the relationshi p between the difference in vehicle weight.

Agency response: The 2003 estimates do include the benefi ts of improved fleet compatibility when the heaviest vehicles are reduced in weight . Compatibility is a safety concern that NHTSA has been investigating for some time now. Th e commenters’ point that any compatibility benefits should be weighed against any disbenef its associated with dow nweighting is logically correct. However, NHTSA research on compa tibility has shown that compatibility is substantially influenced by factor s other than mass, including ve hicle geometry, stiffness, and crush space. While we do not know th e precise effect of these factors, it is fair to say that simply downweighting heavier vehicles would not effectively address the compatibility issue. Thus, there are no currently available analyses that would allow NHTSA or anyone to quantify the compatibility benefits simply from weight reduction.



### Comment: Natural Resources Defense Council (2008-0089-225.1)

They discuss information from the We nzel and Ross study. NHTSA’s own 2003 study demonstrates that safety would have improved if drivers had shifted from LTVs to passenger
cars. Crossover SUVs have lower fa tality risk than truck-based SUVs.

Agency response: This appears to be correct, based on fatal crashes per million registration years. However, the statistics presented by Wenzel a nd Ross should be viewed with caution because they have not been adjusted for differences in driver age and gender, urbanization and geographical region, and average miles driven per year. The unadjusted da ta certainly tends to favor the lighter cars while making pickup trucks look worse. It may also favor crossover SUVs if they are more popular with female drivers in urban areas of low-fatal ity States (relative to truck-based SUVs).

Comment: The “crossover weight” for LTVs, estimated at 5,084 pounds in NHTSA’s 2003 study, will decrease over time as crash-avoidance measures such as ESC reduce single-vehicle crashes (where weight and size helps) relative to multivehicle crashes (where weight and size in the big LTV increases harm in the vehicles hit by that LTV). By restrict ing weight reduction to vehicles weighing 5,000 pounds or more, NHTSA is limiting the cost-effective measures that manufacturers can use to improve fuel economy.

Agency response: Wenzel and Ross’ argument appears to be directionally co rrect. We should note, however, that weight reducti on is not restricted to any pa rticular group of vehicles. Manufacturers may reduce weight in any vehicles th ey want, and will be more inclined to do so if ESC reduces hazards associated with instability of lighter vehicles. The PRIA only uses the 5,000 pound criterion to determine where NHTSA be lieves standards can and should be more stringent than what can be achieved by cost-e ffective weight-neutral technologies alone.IV-24

Comment: Wenzel and Ross question the relationship between weight and safety in NHTSA’s 2003 report. NHTSA’s computation of the 5,000 pound crossover weight for LTVs is based on existing vehicles, and does not take into acc ount future down-weight ing, without downsizing, using lightweight high-strength materials.

Agency response: This argument appears to be directi onally correct. Material substitution would presumably have less effect in single-vehi cle crashes than traditio nal downsizing, and that could shift the crossover weight downwar d. But that has yet to be proven.



### Comment: Sierra Club (2008-0089-0226.1)

Weight reduction across all vehi cles is a safe and effective strategy for improving fuel economy.

Agency response: This is a persistent misconception. Fatality risk will increase in single-vehicle crashes if a given vehicle is redu ced in weight, regardless what happens to other vehicles on the road. In multivehicle crashes, there is some im provement in compatibility if vehicle weights are more uniform, but there is also an overall increas e in crash risk when weights are reduced across
the board.

Comment: The relationship between weight and fata lity risk in the 2003 report, based on the actual fatality rates of 1991-1999 vehicles across the spectrum from light to heavy, overstates the harm if weight is reduced by substituti on of strong, lightwe ight materials.

Agency response: This argument appears to be directi onally correct. Material substitution would presumably have less effect in single-ve hicle crashes than wei ght reduction achieved by downsizing. However, we cannot quantify this futu re effect, because we have no crash data yet
on these future vehicles. We should also note that one of the reasons for higher fatality rates in lighter cars is that they are more crash-prone , even in non-rollover cr ashes. We do not yet understand why this is, and therefore we cannot conc lude that weight redu ction through material
substitution will be less harmful than other forms of weight reduction in this regard.

Views of Other Government Agencies After our proposal was published an d after the comment period had closed for the proposal, EPA published an Advance Notice of Proposed Ru lemaking (ANPRM) on regulating greenhouse gas
emissions under the Clean Air Act. 84 The ANPRM was accompanied by a Vehicle Technical Support Document – Mobile Source. 85 The Technical Support Docu ment contains a discussion on pp. 15 -17 of the safety issues. EPA provide d a brief summary of the issues involved and
cited no new work in that area.

Agency response: The work cited by EPA has already been addressed by NHTSA within the Regulatory Impact Analysis discussion of th e 2002 NAS study and within NHTSA’s responses to other comments to the NPRM docket regarding the Wenzel and Ross study.

84 73 FR 44354 (July 30, 2008).

85 Docket No. EPA-HQ-OAR-2008-0318-0084.IV-25

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 be cause 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 c ontinuous function would minimize incentives for design changes that woul d reduce motor vehicle safety. In a weightbased system, a manufacturer can add weight to a vehicle in or der 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 li ght trucks. A manufactur er 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 maintain ing 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.
Dr. Kahane wrote: ”The objective of the NHTSA study was to calibrate the historical (MY 1991-99) relationships of vehicle mass and fatality ri sk, after controlling fo r driver age/gender, geographical location, and vehicle equipment. In this type of analysis, “vehicle mass” incorporates not only the effect s of mass per se but also the effects of many other size attributes that are historically and/or causally related to ma ss, such as wheelbase, track width and structural integrity. (As vehicles get longer and wi der, they almost always get heavier.)

The study does not claim that mass per se is th e specific factor that increases or decreases fatality risk (except in its role in determin ing the relative Delta V of two vehicles that collide). On the contrary , Chapter 5 of the NHTSA re port shows that certain 4,000- pound SUVs have significantly higher fata l-crash rates than 3,500-pound cars. The study only shows the historical relationship between mass – taking into ac count all the other size attributes that have typica lly varied with mass – and fatal ity risk, for vehicles of the same type. If hist orical 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 si milar changes in fatality risk. (However, the increased use of advanced restraint system s and sophisticated crash avoidance safety devices in recent and future production vehi cles could have a no ticeable impact on the historical relationship between vehicle mass and fa tality risk in future vehicle fleets.)IV-26

In that sense, it is irrelevant whether mass, wheelbase, track width or some other attribute is the principal causal factor on fatality ris k. If you decrease mass, you will also tend to reduce wheelbase, track width and other dimensi ons of size. If manuf acturers respond to this proposal by building lighter vehicles of constant size, the historical relationship between mass and safety w ould gradually weaken.”

Changes in technology could infl uence the relationship between weight and size. There is emerging evidence that vehicle weight can be re duced without reductions in size or safety through the use of high strength, lightweight ma terials. Currently, we do not observe many vehicles built with lightweight materials in the historical data and ther efore cannot separate the impact of size versus weight when lightweight ma terials are utilized. However, the impact of weight, whether it comes from reducing size or ma terial substitution, will be the same for single vehicle impacts (rollovers and fixed and non-fixed object impacts).

Attribute-based standards eliminate the incen tive for manufacturers to respond to CAFE standards in ways harmful to safety. 86 Because each vehicle model has its own target (based on the attribute chosen), attribute- based standards provide no incen tive to build smaller vehicles simply to meet a fleet-wide average, because the smaller vehicles wi ll be subject to more stringent fuel economy and emissions targets.

86 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 standa rds 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”) National Academy Press, Washington, DC (2002), 5, finding 12. Available at http://www.nap.edu/ope nbook.php?record_id=1017 2&page=R1 (last accessed Dec. 2, 2007).IV-27

Fuel Economy Impacts of Other Government Emission Standards

Federal Motor Vehicle Emissions Standards As discussed above, because the addition of weight to a vehicle is only relevant to its ability to
achieve the MY 2011 CAFE standa rds if it occurs in that timeframe, NHTSA only considers
Federal motor vehicle emissions standards th at become effective during the timeframe.

In the NPRM, NHTSA explained that on December 27, 2007, EPA published a final rule for fuel economy labeling that 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 c onditioning operation and cold temp eratures into each vehicle’s fuel economy label. 87 The rule took effect starting w ith MY 2008, and will not impact CAFE standards or test procedures, or add weight to a vehicle or di rectly impact a manufacturer’s ability to meet the CAFE standards. It will, how ever, allow for the collection of appropriate fuel economy data to ensure that exis ting test procedures better re present real-world conditions, and provide consumers with a more accurate estimate of fuel economy based on more comprehensive factors reflecting real-world driving use.

CARB commented that the NPRM had not addre ssed certain federal and California emissions regulations that NHTSA had analyzed in previo us rulemakings, and stated that “NHTSA must analyze the potential effect of these emissions regulations on its propo sed standards.” CARB further stated that “the NPRM must analyze th e impact of California’s ZEV regulations through at least MY 2011,” which the comme nter stated would “r equire NHTSA to consider the impact of rapidly shifting technologies that manuf acturers will apply to meet a combination of government mandates and market conditions, most notably the electrif ication of vehicle
drivetrains.” 88

In response, NHTSA reiterates that emissions sta ndards that are completely phased in before MY 2011 are already accounted for in the agency’s baseline for this rulemaking. EPA’s “Tier 2” standards, which apply to all vehicles currently subject to CAFE and are designed to focus on reducing the emissions most responsible for the ozone and particulate matter (PM) impact from these vehicles, are scheduled to be completely phased in by 2009. 89 EPA’s onboard vapor recovery (ORVR) system standards, which apply to all passenger cars and light trucks below 8,500 pounds GVWR, were completely phased in by MY 2008. 90 Thus, there is no additional effect of these emissions regulations on MY 2011 vehicles for NHTSA to analyze, beyond what manufacturers have already incl uded in their product plans in order to comply with these regulations, which NHTSA already accounts for. 91

NHTSA agrees with CARB, however, that portions of the ZEV standards come into effect during MY 2011, although compliance with these standa rds is also already accounted for in

87 See 71 FR 77872 (Dec. 27, 2006).

88 CARB comments at 10-11, Docket No. NHTSA-2008-0089-0173.

89 See 65 FR 6698 (Feb. 10, 2000).

90 See 59 FR 16262 (Apr. 6, 1994).

91 Additionally, in calculating criteria pollutant emissions factors for analyzing air quality impacts, MOBILE6.2 accounted for EPA’s emission control requ irements for passenger cars and light trucks, including exhaust (tailpipe) emissions, evaporative emissions, and the Tier 2 program. See FEIS § 3.3.2.IV-28

manufacturers’ product plans and thus forms part of NHTSA’s base line analysis. The State of California has established several emission requi rements under section 209(b) of the Clean Air Act as part of its Low Emission Vehicle (LEV) program. California init ially promulgated these section 209(b) standards in its LEV I standards, and has subse quently adopted more stringent LEV II standards, also under section 209(b). The relevant LEV II regulations have been completely phased in for passenger car s and light trucks as of MY 2007.

The LEV II Program has requirements for “zero emission vehicles” (ZEV s) that apply to passenger cars and light trucks up to 3,750 pounds loaded vehicle weight (LVW) beginning in MY 2005, while trucks between 3,750 and 8,500 pounds are phased in to the ZEV regulation from 2007-2012. The ZEV requirements begin at 10 percent of vehicles sold by a manufacturer in California in 2005, and ramp up to 16 percent for 2018 under different paths. California will allow the 16 percent requirement to be met by greater numbers of “partial ZEVs” until 2018, which include ultra-clean gasolin e-engine vehicles and hybrids.

Compliance with the ZEV requirements is most often achieved through more sophisticated combustion management, frequently involving some of the technologies considered by NHTSA in its analysis. The associated improvements and refinement in engine controls generally improve fuel efficiency and have a positive impact on fuel economy. 92 However, such gains may be diminished because the advanced techno logies required by the program can affect the impact of other fuel economy improvements, prim arily due to increased weight. The agency has considered this potential impact in our evaluatio n of manufacturer product plans, many of which voluntarily identified particular models as ZEV or PZEV-compliant. Th is indicates to NHTSA that the manufacturers have already included co mpliance with these stan dards in their product plans, which in turn indicates that compliance with th ese standards is alre ady accounted for in the agency’s baseline.

92 NESCAUM, “White Paper: Comparing the Emissions Reductions of the LEV II Program to the Tier 2 Program,” October, 2003.V-1



### V. FUEL ECONOMY ENHANCING TECHNOLOGIES AND THE
VOLPE MODEL

A. The Volpe Model In developing today’s final CAFE standards, NHTSA has made significant use of results produced by the CAFE Compliance and Effect s Model (commonly referred to as the Volpe model), which DOT’s Volpe National Transportation Systems Center developed specifically to support NHTSA’s CAFE rulemakings.

As discussed above, the agency has used the Volpe model to estimate the extent to which manufacturers could attempt to comply with a given CAFE standard by adding technology to fleets that the agency anticipates they will produce in future model years.
This exercise constitutes a simulation of ma nufacturers’ decisions regarding compliance
with CAFE standards.

The model also calculates the costs, effects, and benefits of technologies it estimates could be added in response to a given CAFE standard. It calculate s costs by applying the cost estimation techniques discussed above and by accounting for the number of affected
vehicles. It accounts for effects such as ch anges in vehicle travel, changes in fuel consumption, and changes in greenhouse gas and criteria pollutant emissions. It does so by applying the fuel consumption estimation t echniques, the vehicle survival and mileage accumulation forecasts, the rebound effect estim ate and the fuel properties and emission factors. Considering cha nges in travel demand and fuel consumption, the model estimates the monetized value of accompanyi ng benefits to society, as discussed in Chapter VIII. The model cal culates both the current ( i.e. , undiscounted) and present ( i.e.

, discounted) value of these benefits.

The Volpe model has other capabilities that facilitate the development of a CAFE
standard. It can be used to fit a mathemati cal function forming the basis for an attributebased CAFE standard, following the steps described below. It can also be used to evaluate many (e.g. , 200 per model year) potential leve ls of stringency sequentially, and identify the stringency at which specific crite ria are met. For example, it can identify the stringency at which net benefits to soci ety are maximized, the stringency at which a specified total cost is reache d, or the stringency at which a given average required fuel economy level is attained. The model can also be used to perform uncertainty analysis ( i.e. , Monte Carlo simulation), in which input estimates are varied randomly according to specified probability distributions, such that the uncertainty of key measures ( e.g. , fuel consumption, costs, benefits) can be evaluated.

Nothing in EPCA requires NHTSA to use the Volpe model. In principle, NHTSA could perform all of these tasks through other mean s. For example, in developing the MY 2011 standards promulgated today, the agency di d not use the Volpe model’s curve fitting routines, because they could not be modified in time to implement the changes discussed below to this aspect of the agency’s analysis . In general, though, these model capabilities greatly increase the agency’s ability to ra pidly, systematically, a nd reproducibly conduct key analyses relevant to the formulati on and evaluation of new CAFE standards.V-2

NHTSA received comments from the Allia nce and CARB encouraging NHTSA to
examine the usefulness of other models. Exam ples of other models and analyses that NHTSA and Volpe Center staff have consider ed for the final rule include DOE’s NEMS, Oak Ridge National Laboratory’s (ORNL) Transitional Alternative Fuels and Vehicles (TAFV) model, Sierra Re search’s VEHSIM model and the California Air Resources Board’s (CARB) analysis supporting Calif ornia’s adopted greenhouse gas emissions standards for light vehicles.

DOE’s NEMS represents the lig ht-duty fleet in terms of fi ve car “manufacturers” and four truck “manufacturers,” twel ve vehicle market classes ( e.g. , “standard pickup”), and sixteen powertrain/fuel combinations ( e.g. , methanol fuel-cell vehicle). Therefore, as currently structured, NEMS is unable to es timate manufacturer-specific implications of attribute-based CAFE standards. The analysis of manufacturer-specific implications is useful in setting the standard, because any gi ven standard will have differential impacts on individual manufacturers, depending on the composition of their ve hicle fleets. In
order to balance national-level costs and benefits, assessment of individual manufacturer’s costs and complia nce strategies is appropriate. 93

TAFV accounts for many powertrain/fuel combin ations, having been originally designed to aid understanding of possible transitions to alternative fueled vehicles, but it also represents the light duty fl eet as four aggregated ( i.e. , industry-wide) categories of vehicles: small cars, large cars, small light tr ucks, and large light tr ucks. Thus, again, as currently structured, TAFV is unable to esti mate manufacturer-specific implications of
attribute-based CAFE standards.

Sierra Research’s vehicle simulation model, VEHSIM, which was originally developed by General Motors, calculates the fuel ec onomy for a specified vehicle design over a specified driving cycle. Despite theoretical advantages in terms of explicit representation of physical phenomena underlying fuel c onsumption, VEHSIM has significant shortcomings as a tool for model-by-model evaluation of the entire future light vehicle fleet. Although submitted after the close of the comment period specified in the NPRM, comments by several state Attorneys General and other state and local official questioned
the need and merits of full vehicle simula tion within the context of CAFE analysis, stating that Computer simulation models such as VEHSIM are not practical except perhaps during vehicle development to determine the performance of specific vehicle models where all ve hicle engineering parameters are known and can be accounted for in the inputs to the model. Such an exercise is extremely data intensive, and extending it to the entire fleet

93 In principle, if all manufactur ers freely traded fuel economy cr edits among themselves, fleetwide estimates of compliance costs and benefits would approximate the sum of individual manufacturer costs and benefits. However, major manufacturers have repeatedly indicated that they do not intend to trade credits, and statutory language prohibits NHTSA from considering the benefits of trading in setting
standards.V-3

makes it subject to multiple errors un less the specific parameters for each vehicle model are known and accounted for in the model inputs. 94

Nevertheless, the Volpe model could, in prin ciple, be modified to use VEHSIM or any
other vehicle simulation tool to estimate fuel consumption. However, in practice, NHTSA and Volpe Center staff are skeptical that doing so will be either feasible or meaningful as long as CAFE analysis continue s to be informed by forecasts of the future vehicle market—forecasts that, though deta iled, will not foreseeably contain the extensive information needed to perform full vehicle simulation. The information required for full vehicle simulation is not only exponentially gr eater than NHTSA currently requests of manufactur ers, but for future vehicles, the information may not yet exist, as manufacturers may not have comp leted the design of future vehicles.

CARB’s analysis of light vehicle GHG em issions standards uses two levels of accounting. First, based on a re port prepared for NESCCAF, CARB represents the lightduty fleet in terms of five “representativ e” vehicles, each with engineering properties estimated by CARB to meaningf ully typify the engineering ch aracteristics of a given type of vehicle ( e.g. , small cars). NHTSA is concerned th at such a limited a number of such vehicles does not reasonably represent the engineering properties of individual vehicle models that vary widely bot h among manufacturers and within manufacturers’ individual
fleets. This concern was reflected in comme nts by the Alliance. For each of these five vehicles, NESCCAF’s report contains the resu lts of full vehicle simulation given several pre-specified technology “packages.” S econd, to evaluate manufacturer-specific regulatory costs, CARB represents each manufac turer’s fleet as two average test weights, one for each of California’s two proposed regul atory classes. Even for a flat standard such as that considered by California, NHTSA is concerned that this level of aggregation
would hinder reasonable estimation of compliance costs faced by individual manufacturers. Further, use of CARB’s methods would not enable NHTSA to estimate manufacturer-specific implications of the at tribute-based CAFE standards. Under an attribute-based standard, the CAFE level requ ired of a given manuf acturer depends on the specific mix of vehicles sold by that manufacturer, not th e average properties of that manufacturers’ fleet. As noted above, it is useful to estimate national level costs and benefits of a standard applied at the level of individual manufacturer ’s fleets by assessing
individual manufacturer’s cost s and compliance strategies.

On the other hand, NHTSA recognizes that a more aggregated representation of the
fleet—such as CARB’s five-veh icle approach—may be the only way that full vehicle simulation could be integrated into CAFE analysis. Alt hough NHTSA has not yet been able to conduct an analysis with the adva ntages of both detail ed representation of

94 Attorneys General of the States of California, Ar izona, Connecticut, Illinois, Maryland, Massachusetts, New Jersey, New Mexico, Oregon, and Vermont, the Ex ecutive Officer of the California Air Resources Board, the Commissioner of the New Jersey Department of Environmental Protecti on, the Secretary of the New Mexico Environment Department, the Secretary of the Commonwealth of Pennsylvania Department of Environmental Protection, and the Corporation Counsel of the City of New York, Supplemental Comments Regarding Alliance of Au tomobile Manufacturers Comments , Docket No. NHTSA-2008-0089- 0495, October 8, 2008, p. 3.V-4

manufacturers’ fleets and full integration of full vehicle simulation, the agency cannot rule out the possibility of such an analysis in the future.

Although the Volpe model has limitations, having considered other t ools and analytical approaches, NHTSA concludes that for this final rule, the Volpe model is a sound and reliable tool available for the development a nd evaluation of potential CAFE standards. However, the agency will continue to cons ider other methods for evaluating potential
CAFE standards in the future as well as to examine ways to improve the Volpe model.

NHTSA notes that some commenters questioned the transparency of the Volpe model,
which Public Citizen and the Center for Bi ological Diversity (CBD) referred to as a “black box.” In response to these comments, the agency notes that model documentation, which is publicly available in the rulemaking docket, explains how the model is installed, how the model inputs (all of which, except for manufacturers’ confidential product plans, are available to the public) and outputs are structured, and how the model is used. The model can be used on any Windows-based pers onal computer with Microsoft Office 2003 and the Microsoft .NET framework installed (t he latter available without charge from Microsoft). The executable ve rsion of the model is availa ble upon request, and has been provided to manufacturers, consulting firm s, academic institutions, governmental and nongovernmental organizations, research institut es, foreign government officials, and a variety of other organizations. The current version of the model was developed using Microsoft Development Environment 2003, and ev ery line of computer code (primarily in C#.NET) has been made available to indi viduals who have requested the code. With the code, anyone is capable of running the model using market forecast data that they obtain or estimate on their own. Given the comprehensive disclosure of information about the Volpe model and the fact that many entities and individuals have made use of it, the characterization of the Volpe model as a “black box” is not accurate.

Although NHTSA currently uses the Volpe model as a tool to inform its consideration of potential CAFE standards, contrary to the assertions of some commenters, the Volpe
model does not determine the CA FE standards NHTSA proposes or promulgates as final regulations. The results it produces are co mpletely dependent on inputs selected by NHTSA, based on the best available informa tion and data available in the agency’s
estimation at the time standards are set. In addition to identifying the input assumptions underlying its decisions, NHTSA provides the ra tionale and justification for selecting those inputs. NHTSA also determines whet her to use the model to estimate at what stringency net benefits are maximized, or to es timate other stringency levels, such as the point where total costs equal total benefits. NHTSA also determines whether to use the
model to evaluate the costs and effects of stri ngencies that fall out side of the scope of maximum feasible. For example, the st andards for the “Technology Exhaustion” Alternative examined by NHTSA and discusse d later in this section, were estimated outside the model, which was subsequently used to estimate corresponding costs and
effects. 95 Finally, NHTSA is guided by the statut ory requirements of EPCA as amended by EISA in the ultimate selection of a CAFE standard.

95 By definition, the “maximum technology” scenario far exceeds the maximum feasible CAFE standard.V-5

NHTSA does not agree with Pub lic Citizen that the agency “does not establish what is technologically feasible a nd economically practicable based on an independent
assessment of the current vehicle fleet and th e available technology to improve the fleet, but rather accepts industry inputs, which are run through the black box of the Volpe model and a variety of ‘optimization’ factors, which are tied to maximizing industry-wide benefits.” The manufacturers’ plans ar e only the starting point for the agency’s
determination of how much t echnology can and should be requ ired consistent with the statutory factors, and the Volpe model is often tested using in puts developed without reliance on manufacturers’ produ ct plans. NHTSA considers the results of analyses conducted by the Volpe model and analyses conducted outside of the Volpe model, including analysis of the impacts of carbon dioxide and criteria pollutant emissions, analysis of technologies that may be avai lable in the long term and whether NHTSA could expedite their entry into the market th rough these standards, and analysis of the extent to which changes in vehicle pri ces and fuel economy might affect vehicle production and sales. Using all of this in formation—not solely that from the Volpe model—the agency considers th e governing statutory factor s, along with environmental
issues and other relevant societal issues such as safety, and pr omulgates the maximum feasible standards based on its best judg ment on how to balance these factors.

This is why the agency cons idered seven regulatory alte rnatives, only one of which maximizes net benefits based on the agency’s determination and assumptions. The others
assess alternative standards that in many cases exceed the poin t at which net benefits are maximized. These comprehensive analyses, whic h also included scenarios with different economic input assumptions as presented in th e FEIS and FRIA, are intended to inform and contribute to the agency’s consideration of the “need of the United States to conserve energy,” as well as the other statutory factor s. 49 U.S.C. § 32902(f). Additionally, the agency’s analysis considers the need of th e nation to conserve energy by accounting for economic externalities of petroleum consumption and monetizing the economic costs of
incremental CO 2 emissions in the social cost of carbon. As mentioned above, NHTSA will continue to consider other methods for determining future CAFE standards in future rulemakings.

NHTSA retained the constrained logistic func tion for the final rule. The considerations
included:

• A relatively flat standard for larger ve hicles acts as a de facto ‘backstop’
for the standard in the event that future market cond itions encourage manufacturers to build very large vehi cles. 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, th us continuing to keep manufacturing fuel-efficient small vehicles available as a compliance option. Infeasible sections of the c urve may be unimportant for the industry at large while having a particular adverse impact on manufacturers thatV-6

specialize in very large or small vehi cles, for example, two-seater sports car.

• The transition from the ‘fla t’ 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 da ta and can potentiall y vary from year to year, rather than being chosen by NHTSA.

NHTSA retained footprint as the attribute for p urposes of this ru lemaking’s attributebased standards in part because we believed changing a vehi cle’s footprint would involve significant costs for manufacturers, probably requiring a redesign of the vehicle. Congress recently mandated that NHTSA set attribute-based fuel economy standards “and express each standard in the form of a mathematical function.” 96 NHTSA uses a continuous, constrained logistic function for expressing the passenger car and light truck standards, which takes the form of an S-curve, and is defined according to the following formula:

( )

( ) 1

1 11

1 FOOTPRINT c d

FOOTPRINT c d TARGET

e
a ba e −

− = ⎛ ⎞

+ −

⎜ ⎟

+ ⎝ ⎠

Here, TARGET is the fuel economy target (in mpg) applicable to vehicles of a given footprint ( FOOTPRINT , in square feet), b and a are the function’s lower and upper asymptotes (also in mpg), e is approximately equal to 2.718, 97 c is the footprint (in square feet) at which the inverse of the fuel econom y target falls halfway between the inverses of the lower and upper asymptotes, and d 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-1 below shows an example of a logistic target function, where b = 20 mpg, a = 30 mpg, c = 40 square feet, and d = 5 square feet:

96 49 U.S.C. § 32902(a)(3)(A).

97 e is the irrational number for which the slope of the function y = number x is equal to 1 when x is equal to zero. The first 8 digits of e are 2.7182818.V-7

Figure V-1. Sample Logistic Curve

Continuous function : NHTSA explained in the NPRM that it exam ined the relative merits of both step
functions and continuous functions in its rulemaking for MY 2008-2011 light trucks, and described the agency’s rationale for c hoosing a continuous function for the CAFE program. A step function, in the CAFE contex t, would separate the vehicle models along the spectrum of attribute magnitudes into discrete groups, and each group would be assigned a single fuel economy target, so th at the average of the groups would be the average fleet fuel economy. A continuous function, in contrast, would assign each vehicle model (and indeed, any vehicle mode l at any point along the spectrum) its own unique fuel economy target, based on its pa rticular attribute ma gnitude. Thus, two vehicles models built by different manufact urers could have the same fuel economy target, but only if they had identical magnit udes of the attribute. In other words, a
continuous function is a mathematical function that defines attribut e-based targets across the entire range of possible attribute values. These targ ets are then applied through a harmonically-weighted formula to derive re gulatory obligations for fleet averages.

The agency fit the fuel economy curves for this final rule for MY 2011 according to the following four step procedure:

In Step 1, NHTSA determined the fuel ec onomies obtained by exhausting available technologies on each vehicle in the MY 2011 updated product plans of the seventeen manufacturers to which the standards appl y (BMW, Chrysler, Daimler, Ferrari, Ford, General Motors, Honda, Hyundai, Maserati, Mits ubishi, Nissan, Porsche, Subaru, Suzuki, 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) L IMIT
UPPER

L

IMI T
L OWERV-8

Tata, Toyota, Volkswagen). In exhausting tec hnologies, the agency has focused this Step on the engineering aspects of available tec hnologies, essentially setting aside economic
considerations.

In Step 2, NHTSA determined initial values for parameters A and B for each vehicle type (passenger car and light truck) as follows. (The values of these parameters will be revised in Step 4.) For pa ssenger cars (respectively, light tr ucks), NHTSA set the initial value of the parameter A to be the harmonic average fuel economy among the vehicles of the given vehicle type (produced by the seve nteen manufacturers used Step 1) comprising the lower tenth (respectively, tenth) percentile of footprint values. NHTSA set the initial
value of B to be the harmonic average fuel eco nomy among the vehicles of the given vehicle type (produced by the seventeen manufacturers) comprising the upper ninth (respectively, sixth) percentile of footprint values. NHTSA set A and B in this manner, rather than fitting them, for example, through regression, in order to ensure that the upper and lower fuel economy values reflect the sm allest and largest models in the fleet. NHTSA chose the percentile values it used by examining the fuel economies of the largest and smallest car and truck models , and determining its best assessment of appropriate cohorts, acknowledging th at there are no canonical choices.

Figure V-2 Distribution of Passenger Car Footprint Values

0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10%<3535.5-3636.5-3737.5-3838.5-3939.5-4040.5-4141.5-4242.5-4343.5-4444.5-4545.5-4646.5-4747.5-4848.5-4949.5-5050.5-5151.5-5252.5-5353.5-5454.5-5555.5-5656.5-5757.5-5858.5-5959.5-60

Footprint (sf)Percent of Vehicle Models smallest 10%

Volkswagen Jetta

and smaller largest 9%

Jeep Wrangler 4-Doo r and largerV-9

Figure V-3 Distribution of Light Truck Footprint Values

0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10%42.5-4344-44.545.5-4647-47.548.5-4950-50.551.5-5253-53.554.5-5556-56.557.5-5859-59.560.5-6162-62.563.5-6465-65.566.5-6768-68.569.5-7071-71.572.5-7374-74.575.5-76

Footprint (sf)Percent of Vehicle Models smallest 10% Hyundai Santa Fe

and smaller largest 6%

Toyota Tundra and larger

In Step 3, NHTSA determined initial values for parameters C and D for each vehicle type as follows. For a given vehicle type , NHTSA set the initial values of C and D to be the values for which the average (equivalently, sum) of the absolute values of the differences between the optimized fuel consumption from Step 1 for the given vehicle type and the values obtained by applying the following function
( )

( ) D C x D C x

e e

A B A x f
/ /

1 1 1 1 ) (

− −

+ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

− + =

to the corresponding vehicle footprints is minimal, where the values of A and B are taken from those determined in Step 2 and where e denotes the base of the natural logarithm (which is approximately equal to 2.71828). That is, NHTSA determined C and D by minimizing the average absolute residual, commonly known as the MAD (Mean Absolute Deviation) approach, of the corres ponding constrained logi stic curve. NHTSA fit the curve in fuel consumption space ra ther than fuel economy space because the manufacturer targets are in te rms of the harmonic average fuel economy, and so it is more important that the curve fit the fuel consum ption data well than that it fit the fuel economy data well. NHTSA uses MAD in this Step instead of minimizing the sum of the square errors (another common approach in curve fitting) in order to lessen the influence of outliers. NHTSA believes that it is more appropriate to use unweighted data in fitting the curve rather than weighting the data by sales because of large variations in model
sales and because each vehicle model contri butes an equal amount of information to understanding the underlying relationship be tween fuel economy and footprint.V-10

For passenger cars, this pro cedure yielded a curve with the following coefficients: A = 37.82 mpg, B = 27.70 mpg, C = 51.41 square feet, D = 1.91 square feet. This curve, shown below on a fuel consumption ( i.e. , gpm) basis, produced an average absolute difference of 18 percent.

Figure V-4 Fitted Curve for Passenger Cars

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

30 35 40 45 50 55 60 65 70

Footprint (sf)Fuel Consumption (gpm)

For light trucks, the same procedure yielde d a curve with the following coefficients: A = 36.43 mpg, B = 26.43 mpg, C = 56.41 square feet, and D = 4.28 square feet. This curve, shown below on a fuel consumption ( i.e. , gpm) basis, produced an average absolute difference of 14 percent.V-11

Figure V-5 Fitted Curve for Light Trucks

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

30 35 40 45 50 55 60 65 70 75 80

Footprint (sf)Fuel Consumption (gpm)

In Step 4, NHTSA determined for each model year and vehicle class the integer value of

t that maximized the societal net benefits (considering the seve nteen manufacturers to which the standards apply) achieved by a fuel economy standard under which fuel consumption targets were defined by the function
( )

( ) /

/ 1 11 ( ) 0.0001 1 xC D

xC D e gx t A BA e −

− ⎛ ⎞

=+ − + ⎜ ⎟

+ ⎝ ⎠
using the values of A and B determined in Step 2, and the values of C and D determined in Step 3. 98 NHTSA reset the values of 1/ A and 1/ B to be 1/ A + 0.0001 t and 1/ B +
0.0001 t , respectively. That is, NHTSA set the stringency of the curves to maximize
societal net benefits.

Parameter Values of the Fuel Econ omy Curves in This Final Rule
Parameter Values for Passenger Cars Parameter Values for Light Trucks

Model A B C D A B C D

2011 31.20 24.00 51.41 1.91 27.10 21.10 56.41 4.28

The corresponding target functi ons are presented below graphically, and on a mile per gallon basis, for both passe nger cars and light trucks:

98 This procedure uniformly shifts the upward and downward (depending on whether t is positive or negative), but on the same gallon per mile basis corresponding to the harmonic averaging of fuel economy
values.V-12V-13

Figure V-6. Final Passenger Car Target Functions

2011

20 25 30 35 40 45

35 40 45 50 55 60 65 70

Footprint (sf)Target (mpg) 2011V-14

Figure V-7. Final Light Truck Target Functions

2011

20 25 30 35 40 45

35 40 45 50 55 60 65 70

Footprint (sf)Target (mpg) 2011

B. Technologies – Costs and Effectiveness

Fuel economy-improving technologies As explained above, pursuant to the Presiden t’s January 26, 2009 memorandum, this final rule establishes passenger ca r and light truck CAFE standards for one year, MY 2011. Although this final rule estab lishes standards for that year alone, the agency undertook a comprehensive analysis of fuel economy-i mproving technologies with a time horizon
similar to the one considered in the 2002 National Academ y of Sciences (NAS) CAFE report. Like NAS, the agency considered tech nologies that are readily available, well known and could be incorporated into vehicl es once production decisions are made (these are referred to as “production intent” tec hnologies). Other tec hnologies considered, called “emerging”, are beyond the research ph ase and under development, but are not widely used at this time. The agency did not consider technologies in the research stage because their costs and/or performa nce are not presently well known.V-15

The agency has elected to include the full analys is in this final rule for several reasons. First, it supplements the an alysis of fuel saving tec hnology released by the 2002 NAS study. Second, it places in meaningful context the portion of the analysis that relates directly to MY 2011, showing whic h technologies are not availa ble for that year and why. The agency typically evaluates technologies w ithin a time context spanning more than a single model year, even if the rulemaking itsel f addresses only a single year as in the current rulemaking, because when manufacturer s add technologies to vehicle models in order to meet CAFE standards, they tend to phase them in over several model years,
consistent with vehicle rede sign and refresh schedules, supp lier contract procedures, the need for testing and validation of new technol ogies, and so forth. Consequently, although
the final rule estab lishes standards for MY 2011 only, NHT SA believes that including the entire technology analysis will increase public understanding of the agency’s estimates for MY 2011 of technology costs, effectiveness, and availability, as well as manufacturer vehicle freshening and redesign cycles.

With that in mind, the following section deta ils the cost and effectiveness estimates completed for technologies in the produc tion intent or emerging technology phase
timeline The estimates are drawn from an an alysis conducted in the summer of 2008. It relied as much as possible on published st udies and confidential product plan data submitted by manufacturers on July 1, 2008 in re sponse to the agency’s NPRM request for comments published May 2, 2008. The anal ysis was conducted by engineers from DOT and Ricardo, an international consulti ng firm that specializes in automotive engineering consulting (discusse d below). The engineering team used all data available at that time, along with their expert opinion to derive cost and effectiveness estimates for technologies either in production or in the emerging stage of production for purposes of this rulemaking.

The agency believes that th e resulting estimates are th e best available for MY 2011, given the information that existed at the time. NHTSA recognizes, however, that the analysis of and public debate over the cost and effectiveness of the various fuel saving technologies is an ongoing one. It recognizes to o that aspects of its technology analysis will likely require updating or otherwise mer it revision for the next CAFE rulemaking. As time progresses, new research occurs, ne w studies become available and product plan information changes. As with all CAFE rulemakings and pursuant to the President’s memorandum, the agency will take a fresh look at all of its technology-related assumptions for the purpose of future rulemakings.

A. NHTSA analyzes what technologies can be applied beyond those in the manufacturers’ product plans One of the key statutory factor s that NHTSA must consider in setting maximum feasible CAFE standards for each model year is the av ailability and feasibility of fuel saving technologies. When manuf acturers submit their product pl ans to NHTSA, they identify the technologies they are planning for each vehicle model in each model year. They also provide their assessments of the costs and eff ectiveness of those fuel saving technologies. The agency uses the manufacturers’ product plan data to asce rtain the “baseline” capabilities and average fuel economy of each manufacturer. Given the agency’s need toV-16

consider economic practicability in determ ining how quickly a dditional fuel saving technologies can be added to the manufactur ers’ vehicle planned fleets, the agency researches and develops, based on the best available informati on and data, its own list of technologies that it believes will be ready for implementation during the model years covered by the rulemaking. This includes developing estimates of the costs and effectiveness of each technology and lead time needs. The resultant technology assumptions form an input into the Volpe model. The model simulates how manufacturers can comply with a given CA FE level by adding technologies beyond those they planned in a systematic, efficient and reproducible manner. The following sections describe NHTSA’s fuel-saving technology assumptions and methodology for estimating them, and their applicability to MY 2011 vehicles.

B How NHTSA decides which technologies to include
1. How NHTSA did this histor ically, and how for the NPRM In the agency’s last two CAFE rulemaki ngs, which established light truck CAFE
standards for MYs 2005-2007 and MYs 2008- 2011, NHTSA relied on the 2002 National Academy of Sciences’ report, “Effectivene ss and Impact of Corporate Average Fuel Economy Standards” 99 (“the 2002 NAS Report”) for estimating potential fuel economy
effectiveness values and associated retail co sts of applying combina tions of technologies in 10 classes of production vehicles. Th e NAS study was commissioned by the agency, at the direction of Congress, in order to pr ovide independent and peer reviewed estimates
of cost and effectiveness numbers. The NAS list was determined by a panel of experts formed by the National Academy of Sciences, and was then peer-reviewed by individuals chosen for their diverse perspectives a nd technical expertise in accordance with procedures approved by the Report Review Committee of the National Research.

In the NPRM for the MY 2011-2015 CAFE sta ndards, NHTSA explained that there has
been substantial advancement in fuel-s aving automotive technologies since the publication of the 2002 NAS Report. New technologies, i.e. , ones that were not assessed in the NAS report, have appeared in the mark et place or are expected to appear in the timeframe of the proposed rulemaking. Als o, new studies have been conducted and reports issued by several other organizations providing new or different information regarding the fuel economy t echnologies that will be available and their costs and effectiveness values. To aid the agency in assessing these developments, NHTSA contracted with the NAS to update the fuel economy section, Chapter 3, of the 2002 NAS Report. However, as NHTSA explained, the NAS update was not available in time for this rulemaking.

Accordingly, NHTSA worked with EPA sta ff to update the technology assumptions, and
used the results as a basis for its NPRM . EPA staff published a related report and
submitted it to the NAS committee. 100

99 National Research Council, “Effectiveness and Imp act of Corporate Averag e Fuel Economy (CAFE) Standards,” National Academy Press, Washington, DC (2002). Available at http://www.nap.edu/openbook.p hp?isbn=0309076013 (last acce ssed October 11, 2008).

100 EPA Staff Technical Report: Cost and Effectiven ess Estimates of Technologies Used to Reduce LightDuty Vehicle Carbon Dioxide Emissions, EPA 420-R-08-008, March 2008.V-17

2. NHTSA’s contract with Ricardo for the final rule NHTSA specifically sought comment on the es timates, which it had developed jointly with EPA, of the availability, applicabili ty, cost, and effectiveness of fuel-saving technologies, and the order in whic h the technologies were applied. See 73 FR 24352, 24367. To aid the agency in analyzing those comments and increasing the accuracy, clarity and transparency of its technology assumptions and methodologies employed in developing them, it hired an international c onsulting firm, Ricardo, which specializes in automotive engineering consul ting. Ricardo, which describes itself as an eco-innovation technology company, is a leading inde pendent provider of technology, product innovation, engineering solutions, software and strategic consulting. Its skill base
includes the state-of-the-art in low emissi ons and fuel-efficient powertrain and vehicle technology. Its customers include government agencies here and abroad and the world’s automotive, transport and new-energy industries. 101 For example, it has provided technical consulting on low CO 2 strategies to the UK Depa rtment for Transport (DfT). 102 Additionally, in December 2007, Ricardo completed an important study for EPA titled “A Study of Potential Effectiveness of Carbon Dioxide Reducing Vehicle Technologies.” 103

Ricardo’s role was as a technical advisor to NHTSA staff. In this capacity, Ricardo helped NHTSA undertake a comprehensive review of the NPRM technology assumptions and all comments received on those assumpti ons, based on both old and new public and
confidential manufacturer information. NHTSA and Ricardo staff reviewed and compared comments on the availability and a pplicability of technologies, and the logical progression between them. NH TSA also reviewed and compared the methodologies used for determining the costs and effectiveness of the technologies as well as the specific estimates provided. Relying on the technica l expertise of Ricardo and taking into
consideration all the information availabl e, NHTSA revised its estimates of the availability and applicability of many technologies, and revi sed its estimate of the order in which the technologies were applied and how they are differentiated by vehicle class,
as well as the costs and effectiveness estimates and used the revised numbers in analyzing alternative levels of stringency.

While NHTSA sought Ricardo’s expertise and re lied significantly on their assistance as a neutral expert in developing its technical assumptions, it re tained responsibility for the final estimates. The agency believes that the representation of technologies for MY 2011—that is, estimates of the availability, appl icability, cost, and effectiveness of fuelsaving technologies, and the order in which the technologies were applied—used in this

101 More information about Ricardo’s work is availa ble at their website, http://www.ricardo.com (last accessed September 20, 2008). Its 2007 Annual Report provides a comprehensive view of some of its
current work. See http://www.ricardo.com/investors/downlo ad/annualreport2007 .pdf (last accessed September 22, 2008).

102 Ricardo UK Ltd., “Understanding manufacturers’ re sponses to policy measures to incentivise fuel efficiency,” Oct. 5, 2007. Available at http://www.dft.gov.uk/consul tations/closed/co2emissions/ricardorepo rt.pdf (last accessed Oct. 4, 2008).

103 A slightly updated (June 2008) version of Ricardo’s study for EPA is available on EPA’s website, at http://www.epa.gov/otaq/technol ogy/420r08004a.pdf (last acce ssed September 20, 2008).V-18

rulemaking is more accurate than that used in the NPRM, and is the best available for purposes of this rulemaking.

C. What technology assumptions ha s NHTSA used for the final rule? 1. How do NHTSA’s technology assumptions in the final rule differ from those
used in the NPRM?
This final rule uses the same basic fram ework as the NPRM. However, NHTSA made several changes to its technology assumpti ons based on comments and information received during the rulemaking. As in the NPRM and the MY 2008-2011 light truck rule, the agency relied on the Volpe m odel CAFE Compliance and Effects Modeling System which was developed by the Depart ment or Transportation’s Volpe National Transportation Systems Center (Volpe Center ) to apply technologies. The model, known as the Volpe model, is the primary tool th e agency has used in conducting a “compliance analysis” of various CAFE stringencies. The Volpe model relied on the same types of technology related inputs as in previous rule s, including market data files, technology cost and effectiveness estimates by vehicle classification, technology synergies, phase-in rates, learning curve adjustments, and technology decision trees.

Regarding the decision trees, both the stru cture of the trees and ordering of the technologies were revised. The decision trees have been expanded so that NHTSA is
better able to track the incremental and net/ cumulative cost and effectiveness of each technology, which substantially improves the “a ccounting” of costs and effectiveness for
the final rule. 104 The revised decision trees also ha ve improved integration, accuracy, and technology representations.

In revising the decision trees, NHTSA updated, combined, split and/or renamed technologies. Several technol ogies were added, while others were deleted. The three technologies that were deleted because they do not appear in either public or confidential data and are primarily in the research phase of development are: Camless Valve Actuation, Lean-Burn Gasoline Direct-Inje ction and Homogenous Charge Compression

104 In addition to the (simplified) decision trees, as published in this document, NHTSA also utilized “expanded” decision trees in the final rule analysis. Expanded decision trees graphically represent each unique path, considering the branch points available to the Volpe model, which can be utilized for applying fuel saving technologies. For instance, the engine decision tree shown in this document has 20 boxes representing engine technologies, whereas the expanded en gine decision tree requires a total of 45 boxes to accurately represent all available application varian ts. Expanded decision trees presented a significant improvement, compared to the NPRM analysis, in the overall assessment and tracking of applied technologies since they allowed NHTSA staff to accur ately view and assess both the incremental and the accumulated, or net cost and effectiv eness at any stage of technology application in a decision tree. Because of the large format of th e expanded decision trees, they co uld not be included in the Federal Register, so NHTSA refers the reader to Docket No . NHTSA-2008-0177. Expanded decision trees for the engine, electrification/transmission/hybridization, and the vehicle technologies (three separate decision trees) were developed for each of th e 12 vehicle technology applicati on classes and the three expanded decision trees for the Large Car subclass have been placed in the docket as an example for the reader’s
information.V-19

Ignition. 105 NHTSA also added three advanced technologies based on confidential
manufacturer submissions which showed these technologies as being emerging and currently under development. These technol ogies are: Combustion Restart, Exhaust Gas Recirculation Boost, and Plug-in Hybrids.

The Volpe model was modified to allow a non- linear phase-in rate across the five model years, rather than a constant phase-in rate as was used in the NPRM and in previous rules. Most technology applications have tighter pha se-in caps in the early years to provide for
additional lead time.

In the NPRM, NHTSA applied volume-based learning factors to technology costs for the first time. These learning factors were developed using the parameters of learning threshold, learning rate (decremented over two cy cles), and the initial (unlearned) cost. In the NPRM, NHTSA applied a learning rate discount of 20 percent each time a technology was projected for use on 25,000 vehi cles per manufacturer, which was the threshold volume for learning rate discounts. The discounts were only taken twice, at 25,000 and 50,000 vehicles. A technology was view ed as being fully learned out at 100,000 units.

The agency also reconsidered volume-ba sed learning factors and made significant revisions. First, the volume learning is now applied on an industry basis as opposed to a
manufacturer basis. This take s into account the fact that the automobile industry shares best practices and that manufact urers learn from that sharing to produce their vehicles at
lower costs. For the final ru le, the revised learning thresh old is set to 300,000 vehicles per year by the automobile industry. This number was developed based on comments indicating that many of the publicly available technology co st estimates are based on production quantities of 900,000 to 1.5 million vehi cles by at least 3 manufacturers. The agency notes, however, that none of the technologies applie d in MY 2011 receive volume-based learning, due to the time frame applicable.

For the technologies applied in the final rule , a time-based learning factor was used in response to public comments from Ford and othe rs. This learning f actor was not applied in the NPRM. Time-based learning is applie d to widely available, high volume, stable and mature technologies typically purcha sed under negotiated multi-year contractual agreement with suppliers. This type of an agreement is typical of most supplier-provided fuel saving technologies. With time-based le arning, the initial cost of a technology is reduced by a fixed amount in its second and subs equent year of availa bility. A fixed rate 3 percent year-over-year cost reduction is applied up to a maximum of 12 percent cost
reduction.

In the NPRM NHTSA divided vehicles into ten subclasses based on technology applicability: four for cars and six for truc ks. NHTSA assigned passenger cars into one of the following subclasses: Subcompact, Co mpact, Midsize, or Large Car. NHTSA

105 We note that GM included lean burn HCCI in its restructuring plans submitted to Congress, but the restructuring plans were submitted too late for the ag ency to consider them in its technology analysis, among other reasons. GM Restructuring Plan, p. 22.V-20

assigned light trucks into one of the follo wing subclasses: Minivan, Small SUV, Medium SUV, Large SUV, Small Pickup Truck, or Large Pickup Truck. In its 2008 NPRM for MY 2011-2015, NHTSA included some differentiati on in cost and effectiveness numbers
between the various classes to account for differences in technology costs and
effectiveness that are observed when technologies are applie d on to different classes and
subclasses of vehicles.

For the final rule, NHTSA, working with Ricardo, increased the accuracy of its technology assumptions by reexamining the subclasses developed for the purpose of modeling technology application. For passe nger cars, NHTSA divided vehicles into eight subclasses based on technology applicab ility by creating a performance class under each of the four subclasses. For trucks, NHT SA established four subclasses, including a minivan subclass, and small, midsize and large SUV/Pickup/Van subclasses. NHTSA also provided more differentiation in the costs and effectiveness values by vehicle subclass. The agency found it important to ma ke that differentiation because the agency estimated that some technologies would have different implications for large vehicles
than for smaller vehicles.

In summary, the revisions to NHTSA’s me thodology for technology application and cost and effectiveness estimates are designed to respond to comments, many of which focused
on various inaccuracies and l ack of clarity in the NPRM. NHTSA believes that the methodology for the final rule, as compared to the NPRM methodology, is much clearer, more accurate, and more representative of likely manufacturer behavior, although, of course, manufacturers are free to respond to the CAFE standards with whatever application of technology they choose. The revised techno logy related assumptions help substantially ensure the technological feasib ility and economic prac ticability of the MY 2011 CAFE standards promulga ted in this final rule.

2. How are the technologies applied in the model? For the final rule, as in the NPRM, NHTSA made significant use of the CAFE Volpe
model as discussed above. The NPRM c ontained a detailed discussion of the Volpe model and specifically stated its two primar y objectives as 1) identifying technologies that manufacturers could apply in order to comply with a specified CAFE standard, and 2) calculating the cost and eff ects of manufacturers’ technol ogy applications. The NPRM also discussed other modeling systems and approaches that NHTSA considered to accomplish these same objectives, and also discusses why ultimately the agency chose to use the Volpe model (see 79 FR 24352, 24391). However, having done so for this final rule does not limit the agency’s ability to use another approach for future CAFE rulemakings, and NHTSA will continue to consider other methods for estimating the costs and effects of adding technolog ies to manufacturers’ future fleets.

The Volpe model relies on several inputs and data files to conduct the compliance analysis, and each of these are discussed in detail in the NPRM. Many of these inputs
contain economic and environmen tal data required for the full CAFE analysis. However, for the purposes of applying technologies, th e subject of this se ction, the Volpe model primarily uses three data files, one that contains data on th e vehicles being manufactured,V-21

one that identifies the appropr iate stage within the vehicl e’s life-cycle for the technology to be applied, and one that contains data/p arameters regarding the available technologies the model can apply. These inputs are discussed below.

The Volpe model begins with an “initial stat e” of the domestic vehicle market, which in this case is the market for passenger cars a nd light trucks to be sold during the period covered by the final rule. The vehicle mark et is defined on a model, engine, and transmission basis, such that each defined ve hicle model refers to a separately-defined engine and a separately-defined transmission. For the final rule, this represented roughly 5,500 cars and trucks, 700 engines, and 600 tr ansmissions. The information, which is
stored in a file called the “v ehicle market forecast,” is informed significantly by product plans provided to NHTSA by vehicle manufacturers. 106 However, the Volpe model does not require that the market forecast be base d on confidential product plans, and the model is often tested using input files devel oped using only publicly- and commerciallyavailable information. EPCA does not require NHTSA to use manufacturers’ confidential product plans as a basis for setting future CAFE standards, and the agency
will continue to base its market forecasts on wh atever it determines is the best available information, whether from public, commercia lly-available, or confidential sources.

In addition to containing data about each ve hicle, engine, and tran smission, this file contains information for each technology under c onsideration as it pertains to the specific vehicle (whether the vehicle is equipped with it or not), th e model year the vehicle is undergoing redesign, and information about th e vehicle’s subclass for purposes of technology application.

The market forecast file provides NHTSA the ability to identify, on a technology by technology basis, which technologies may already be present (manufactured) on a particular vehicle, engine, or transmission, or which technolo gies are not applicable (due to technical considerations) to a particular vehicle, engi ne, or transmission. These identifications are made on a model-by-mode l, engine-by-engine, and transmission-bytransmission basis. For example, if Manuf acturer X advises NHTSA that Vehicle Y will be manufactured with Technology Z, then fo r this vehicle Technology Z will be shown as used. Or alternatively, NHTSA might conclu de based on its own assessment that for a given four cylinder engine, Manufacturer A ca nnot utilize a particular Technology C due to an engineering issue that prohibits it. In this case, NHTSA would, in the market forecast file, indicate that Technology C should not be applied to this particular engine ( i.e. , is unavailable). Since multiple vehicle models may be equipped with this engine, this may affect multiple models. In using th is aspect of the market forecast file, NHTSA ensures the Volpe model only app lies technologies in an appr opriate manner, since before any application of a technology can occur, the model checks the market forecast to see if it is either already pr esent or unavailable.

106 The market forecast is developed by NHTSA using th e 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 agen cy is prohibited by federal law from disclosing.V-22

Manufacturers typically plan vehicle changes to coincide with certain stages of a vehicle’s life cycle that are appropriate for the change, or in this case the technology being applied. For instance, some technologies ( e.g. , those that require significant revision) are nearly always a pplied only when the vehicle is expected to be redesigned. Other technologies can be appl ied only when the vehicle is expected to be refreshed or redesigned and some others can be applied at any time, regardless of whether a refresh or redesign event is conducted. Accordingly, th e model will only appl y a technology at the particular point deemed suitable. These constraints are intended to produce results consistent with manufacturers’ product planning practices. For each technology under consideration, NHTSA stipulates whether it can be applied a ny time, at refresh/redesign, or only at redesign. The data forms another input to the Volpe mode l, as discussed in detail below, called the Technology Refresh and Redesign Application table. Each manufacturer identifies its pla nned redesign model year for each of its vehicles, and this
data is also stored in the market forecast file.

NHTSA assigns one of 12 subclasses to each vehicle manufactured in the rulemaking period. The vehicle subclass data is used for the purposes of technology application.
Each vehicle’s class is stored in the mark et forecast file. When conducting a compliance analysis, if the Volpe model seeks to apply technology to a particular vehicle, it checks the market forecast to see if the technology is available and if the re fresh/redesign criteria are met. If these conditions are satisfied, the model determines the vehicle’s subclass,
which it then uses to reference anothe r input called the technology input file.

In the technology input file, NHTSA has de veloped a separate set of technology data
variables for each of the twelve vehicle subclasses. Each set of variables is referred to as an “input sheet,” so for example, the subc ompact input sheet holds the technology data that is appropriate for the subcompact subc lass. Each input sheet contains a list of technologies available for members of the pa rticular vehicle subclass. The following items are provided for each technology: a br ief description, its a bbreviation, the decision
tree with which it is associat ed, the (first) year in which it is available, the upper and lower cost and effectiveness (fuel consump tion reduction) estimates, the learning type and rate, the cost basis, its appl icability, and the phase-in values.

The input sheets are another method NHTSA uses to determine how to properly apply, or in some cases constrain, a technology’s applic ation, as well as to establish the costs and fuel consumption changes that occur as it is applied. Examples of how technologies are applied (or constrained) include the “Applicability” variable: if it is set to “TRUE,” then the technology can be applie d to all members of the ve hicle subclass (a value of “FALSE” would prevent the Volpe model from applying the technology to any member). Another example would be the “Year Availabl e” variable, which if set to “2012” means the model can apply it to MY 2012 and later members, but cannot apply the technology to MY 2011 models. The “Learning Type” a nd “Learning Rate” defi ne reductions in technology costs, if any are appropriate, th at the Volpe model may apply under certain conditions, as discussed in the Learning Curv e section below. “Phase-in Values” are
intended to address the various constraints th at limit a manufacturer’s ability to apply technologies within a short period of time. For phase-ins, once the model applies a givenV-23

technology to a percentage of a given manufacturers’ fleet up to a specified phase-in cap, the model then ceases to apply it further instead applying other technologies.

Perhaps the most important data containe d in the input sheets are the cost and
effectiveness information associated with each technology. One important concept to
understand about the cost and e ffectiveness values is that they are “incremental” in nature, meaning that the estimates are “referen ced” to some prior t echnology state in the decision tree in which the applied technol ogy is represented, typi cally the preceding technology. Therefore, when considering valu es shown in the input sheet, the reader
must understand that in all but a few cases they cannot fully deduce the accumulated or “NET” cost and effectiveness, refere nced back to the base condition ( i.e. , start of the decision tree), without performing a more de tailed analysis. The method for conducting this analysis, and a brief exam ple of how it is done, is di scussed in the Decision Tree
section below. For the fina l rule, to help readers bette r understand Volpe model net or accumulated costs and fuel consumption reductions, NHTSA has published net values to key technology locations on the decision trees ( e.g. , to diesel engine conversion, or a strong hybrid). See the Tables showi ng Approximate Net Technology Costs and Approximate Net Technology Effectiveness. Th e tables have been produced for each of
the four vehicle subclasses in the passenger car, performance passenger car, and light truck vehicle groups.

The incremental costs of some technologies are dependent on certain factors specific to the vehicle to which they are applied. For instance, when the Material Substitution technology is applied, the cost of application is based on a co st per unit weight reduction, in dollars per pound, since the weight removed is a percentage of the curb weight of the vehicle (which differs from one vehicle to the next). Similarly, some engine technologies
need to be calculated on a co st per cylinder basis, or a cost per c onfiguration basis ( i.e. , a cost per bank basis, so that a V-configured en gine would cost twice as much as an in-line, single bank engine). For each technology, the input sheet also contains a Cost Basis
variable which indicates whether the costs need to be adjusted in this manner. This functionality, some of which is new for the final rule, allows NHTSA to estimate more accurately the costs of tec hnology application, since in th e NPRM the vehicles in a subclass were assumed to have common cyli nder counts and configurations (thus the
costs were underestimated for some ve hicles and overestimated for others).

Lastly for the technology input file, the term “synergy” as it applies to the Volpe modeling process refers to the condition that occurs when two or more technologies are applied to a vehicle and their e ffects interact with each other, resulting in a different net
effect than the combination of the indivi dual technologies. The term synergy usually connotes a positive interaction ( e.g. , 1 + 1 is more than 2), but as used here it also includes negative interactions ( e.g. , 1 + 1 is less than 2). Synergies are discussed in greater detail below, and the values for the synergy factors NHTSA us ed in the final rule are stored in the technology input file.

In some cases more than one decision tree path can lead to a subsequently applied technology. For example, the power split hybri d technology can be reached from one ofV-24

two prior transmission technologies (CVT or DCTAM). Accordingly the incremental cost and effectiveness for applying the tec hnology may vary depending on the path and the modifications made in the prior technology. To ensure accurate tracking of net costs and effectiveness, the Volpe model utilizes path correction factors, as discussed further in
the decision tree discussion below. This functio nality is an improvement to the final rule, and the specific factors used are stored in th e technology input sheets. A copy of the final rule input sheets, titled “2011-2015_LV_ CAFE_FinalRuleIn putSheets20081019.pdf,”
can be obtained from the final rule docket.

One additional concept to understand about how the Volpe model functions is called an “engineering constraint,” a programmatic me thod of controlling t echnology application that is independent of those discussed above. NHTSA has determined that some technologies are only suitable or unsuitable wh en certain vehicle, e ngine, or transmission conditions exist. For example, secondary axle disconnect is only suitable for 4WD vehicles, and cylinder deactivation is unsu itable for any engine with fewer than 6 cylinders, while material substitution is onl y available for vehicles with curb weights greater than 5,000 pounds. Additionally, in response to comments received, an engineering constraint was a dded for purposes of the final rule to prevent the cylinder deactivation technology from being applie d to vehicles equipped with manual transmissions, due primarily to drivea bility and NVH concerns documented by the commenter. Where appropriate and requi red, NHTSA has utilized engineering constraints to ensure accurate applic ation of the fuel saving technologies.

3. Technology application decision trees Several changes were made to the Volpe m odel between the analysis reported in the NPRM and the final rule. This section will discuss two of those changes: first, the updates to the set of tech nologies; and second, the update s to the logical sequence for progressing through these technologies, which NHTSA describes as “decision

trees.”

As discussed above, the set of technologies considered by the agency has evolved since the NPRM. The set of technologies now included in the Volpe model is shown below in Table V-1, with abbreviations used by the model to refer to each technology in the interest of brevity.V-25

Table V-1. Revised Final Rule Technology Set for Volpe Model Technology Abbreviation
Low Friction Lubricants LUB Engine Friction Reduction EFR VVT - Coupled Cam Phasing (CCP) on SOHC CCPS

Discrete Variable Valve Lift (DVVL) on SOHC DVVLS Cylinder Deactivation on SOHC DEACS VVT - Intake Cam Phasing (ICP) ICP VVT - Dual Cam Phasing (DCP) DCP

Discrete Variable Valv e Lift (DVVL) on DOHC DVVLD Continuously Variable Va lve Lift (CVVL) CVVL Cylinder Deactivation on DOHC DEACD Cylinder Deactivation on OHV DEACO VVT - Coupled Cam Phasing (CCP) on OHV CCPO

Discrete Variable Valv e Lift (DVVL) on OHV DVVLO

Conversion to DOHC with DCP CDOHC

Stoichiometric Gasoline Di rect Injection (GDI) SGDI

Combustion Restart CBRST Turbocharging and Downsizing TRBDS Exhaust Gas Recirculation (EGR) Boost EGRB

Conversion to Diesel (from CBRST) DSLC

Conversion to Diesel (from TRBDS) DSLT Electric Power Steering EPS Improved Accessories IACC 12V Micro-Hybrid MHEV Higher Voltage/Improved Alternator HVIA Integrated Starter Generator ISG 6-Speed Manual/Improved Internals 6MAN Improved Auto. Trans. Controls/Externals IATC Continuously Variable Transmission CVT 6/7/8-Speed Auto. Trans w ith Improved Internals NAUTO

Dual Clutch or Automated Manual Transmission DCTAM Power Split Hybrid PSHEV 2-Mode Hybrid 2MHEV Plug-in Hybrid PHEV Material Substitution (1%) MS1 Material Substitution (2%) MS2 Material Substitution (5%) MS5 Low Rolling Resistance Tires ROLL Low Drag Brakes LDB Secondary Axle Disconnect SAX Aero Drag Reduction (10%) AEROV-26

As in the NPRM, each technology is assigned to one of the five following categories based on the system it affects or impacts: e ngine, transmission, electrification/accessory, hybrid or vehicle. Each of these categories has its own decision tree that the Volpe model uses to apply technologies sequentia lly during the compliance analysis. The decision trees were designed and configured to allow the Volpe model to apply technologies in a cost-effective, logical order that also cons iders ease of implementation. For example, effective software or cont rol logic changes are implemented before replacing a component or system with a comp letely redesigned one, which is typically a much more expensive option.

Each technology within the decision trees ha s an incremental cost and an incremental effectiveness estimate associated with it, a nd the estimates are speci fic to a particular vehicle subclass. Each technology’s incremen tal estimate takes into account its position in the decision tree path. If a technology is located further down the decision tree, the
estimates for the costs and effectiveness values attributed to that technology are influenced by the incremental estimates of costs and effectiveness values for prior technology applications. In essence, this approach accounts for “in-path” effectiveness synergies and cost effects that occur between the technologies in the same path. When comparing cost and effectiveness estimates from various sources and those provided by commenters, it is vital that the estimates are ev aluated in the proper context, especially as concerns their likely positi on in the decision trees and ot her technologies that may be present or missing. Not all estimates provi ded by commenters can be considered an “apples-to-apples” comparison with those used by the Volpe model, since in some cases the order of application, or included technology c ontent, is inconsistent with that assumed
in the decision tree.

For the final rule, significant revisions have been made to the sequence of technology applications within the decision trees, and in some cases the paths themselves have been modified and additional paths have been adde d. The additional pa ths allow for a more accurate application of technology, insofar as the model now considers the existing configuration of the vehicle when applying technology. In this analysis, single overhead camshaft (SOHC), dual overhead camshaf t (DOHC) and overhead valve (OHV) configured engines now have separate pa ths that allow for unique path-dependent versions of certain engine technologies. Thus, the cylinder deactivation technology (DEAC) now consists of three unique versions that depend on whet her the engine being evaluated is an SOHC, DOHC or OHV desi gn; these technologies are designated by the abbreviations DEACS, DEACD and DEACO, respectively, to designate which engine path they are located on. Similarly the la st letter for the Coupled Cam Phasing (CCP) and Discrete Variable Valve Lift (DVVL) abbr eviations are used to identify which path the technology is applicable to.

Use of separate valvetrain paths and unique path-dependent tec hnology variations also
ensures that the incremental cost and e ffectiveness estimates properly account for technology effects so as not to “double-coun t.” For example, in the SOHC path, the incremental effectiveness estimate for DVVLS assumes that some pumping loss reductions have already been accomplishe d by the preceding technology, CCPS, whichV-27

reduces or diminishes the effectiveness estimate for DVVLS because part of the efficiency gain associated with the reduc tion of the pumping loss mechanism has already occurred. Commenters pointed out seve ral instances in the NPRM where doublecounting appeared to have occurred, and the accounting approach used in the final rule
resolves these concerns.

In reviewing NPRM comments, NHTSA noted several questions rega rding the retention of previously applied technologies when more advanced technologies ( i.e. , those further down the decision tree) were applied. In re sponse, NHTSA has clarified the final rule
discussions on this issue. In both the NPRM and final rule, as appr opriate and feasible, previously-applied technologies are retain ed in combination with the new technology being applied, but this is not always the case. For instance, one exception to this would be the application of diesel technology, where the entire engine is assumed to be replaced, so gasoline engine technologies canno t carry over. This exception for diesels, along with a few other technologies, is docum ented below in the detailed discussion of changes to each decision tr ee and corresponding technologies.

As the Volpe model steps through the decision trees and applies technologies, it
accumulates total or “NET” cost and effec tiveness values. Net costs are accumulated using an additive approach while net effectiveness estimates are accumulated multiplicatively. To help readers better understand the accumulation process, and in response to comments expressing confusion on this subject, the following examples demonstrate how the Volpe model calculates net values.

Accumulation of net cost is explained first as this is the simpler process. This example uses the Electrification/Accessory decisi on tree sequentially appl ying the EPS, IACC, MHEV, HVIA and ISG technologies to a s ubcompact vehicle using the cost and effectiveness estimates from its input sheet. As seen in Table V-2 below, the input sheet
cost estimates have a lower and upper value which may be the same or a different value ( i.e. , a single value or a range) as shown in columns two and three. The Volpe model first averages the values (column 4), and then sums the average values to calculate the net cost of applying each technology (column 5). Accordingly, the net cost to apply the MHEV technology for example would be ($112.50 + $192.00 + $372.00 = $676.50). Net
costs are calculated in a similar manner for all the decision trees.V-28

Table V-2. Sample Volpe Model Net Cost Calculation

Tech. Abrev. Lower INCR

Cost Upper INCR

Cost Av g . INCR

Cost NET Cost

EPS 105.00 $ 120.00 $ 112.50 $ 112.50 $

IACC 173.00 $ 211.00 $ 192.00 $ 304.50 $

MHEV 372.00 $ 372.00 $ 372.00 $ 676.50 $

HVIA 84.00 $ 84.00 $ 84.00 $ 760.50 $
ISG 1,713.00 $ 1,713.00 $ 1,713.00 $ 2,473.50 $ 

### Example Net Cost Calculation: Elect./Acc. Path, Subcompact Vehicle Subclass

The same decision tree, technologies, and vehi cle are used for the example demonstrating
the model’s net effectiveness calculation. Table V-3 below shows average incremental effectiveness estimates in column two; this value is calculated in the same manner as the cost estimates above (average of lower and upper value taken from the input sheet). To calculate the change in fuel consumption due to application of the EPS technology with incremental effectiveness of 1.5 percent (o r 0.015 in decimal form, column 3), when applied multiplicatively, means that the vehicl e’s current fuel consumption ‘X’ would be reduced by a factor of (1 – 0.015) = 0.985, 107 or mathematically 0.985*X. To represent the changed fuel consumption in the normal fa shion (as a percentage change), this value is subtracted from 1 (or 100%) to show the net effectiveness in column 5.

As the IACC technology is applied, the vehicle’ s fuel consumption is already reduced to 0.985 of its original value. Therefore th e reduction for an additional incremental 1.5 percent results in a new fuel consum ption value of 0.9702, or a net 2.98 percent effectiveness, as shown in the table. Net effectiveness is calculated in a similar manner
for the all decision trees. It should be noted that all incr emental effectiveness estimates were derived with this multiplicative approach in mind; calculating the net effectiveness using an additive approach will yield a different and incorrect net effectiveness.

107 A decrease in fuel consumption (FC) means the fuel economy (FE) will be increased since fuel consumption and economy are related by the equation FC = 1/FE.V-29

Table V-3. Sample Volpe Model Net Effectiveness Calculation

Tech.

Abrev. Av g

. INCR

Eff. % Av g . INCR

Eff. (decimal) Multiplicative FC Reduction Current FC * (1-Avg INCR) Net

Effect. (1 - Red) EPS 1.50% 0.0150 1 * (1 - 0.015) = 0.985 1.50% IACC 1.50% 0.0150 0.985 * (1 - 0.015) = 0.9702 2.98% MHEV 1.95% 0.0195 0.9702 * (1 - 0.0195) = 0.9513 4.87% HVIA 0.55% 0.0055 0.9513 * (1 - 0.0055) = 0.9461 5.39%

ISG 6.10% 0.0610 0.9461 * (1 - 0.061) = 0.8884 11.16% 

### Example Net Effectiveness Calculation: Elect./Acc. Path, Subcompact Vehicle Subclass

To improve the accuracy of accumulating net cost and effectiveness estimates for the final rule, “path-dependent corrections” we re employed. The NPRM analysis had the potential to either overestim ate or underestimate net cost and effectiveness depending on which decision tree path the Volpe model fo llowed when applying the technologies. For example, if in the NPRM analysis a diesel technology was applied to a vehicle that followed the OHV path, the net cost and effec tiveness could be diffe rent from the net
estimates for a vehicle that followed the OHC path even though the intention was to have
the same net cost and effectiveness. In order to correct this issue, the final rule analysis has added path-dependent correction tables to the input sheets. The model uses these tables to correct net cost and effectiveness estimate differences that occur when multiple paths lead into a single te chnology that is intended to have the same net cost and effectiveness no matter which path was followed. 108 Path-dependent corrections were used when applying cylinder deactivation (on the DOHC path), turbocharging and downsizing, diesel and strong hybrids. This is essentially an a ccounting issue and the path-dependent corrections are meant to remedy the accuracy issues reported in the NPRM comment responses.

The following paragraphs explain, in greater de tail, the revisions to the decision trees and technologies from the NPRM to the final ru le. Revisions were made in response to comments received and pursuant to NHTSA’s an alysis, and were made to improve the accuracy of the Volpe compliance analysis, or to correct other concerns from the NPRM analysis.

Engine Technology Decision Tree Figure V-8 below shows the final rule decision tree for the engine technology

108 The correction tables are used for path deviations within the same decision tree. However, there is one exception to this rule, specifically that the tables are used to keep the model fr om double-counting cost and
effectiveness estimates when both the CBRST and MH EV are applied to the same vehicle. Both technologies try to accomplish the same goal of reduc ing fuel consumption, by limiting idle time, but through different means. If either of these technologies exists on a ve hicle and the Volpe model applies the other, the correction tables are used to remove the cost and effectiveness estimates for CBRST, thus ensuring that double-counting does not occur.V-30

category. For the final rule, NHTSA removed camless valve actuation (CVA), leanburn GDI (LBDI), and homogenous charge compression ignition (HCCI) from the decision trees because these technologies were determined to be st ill in the research phase of development. NHTSA did not receive any new information or comments that suggested these technologies are unde r development, so NHTSA removed them from the decision trees. At the top of the engine decision tree Lo w Friction Lubricants (LUB) and Engine Friction Reduction (EFR) te chnologies are retained as utilized in
the NPRM.

As stated above, SOHC, DOHC and OHV engines have separate paths, whereas as the NPRM only made the distinction between OHC and OHV engines. The separation of SOHC and DOHC engines allowed the model to more accurately apply unique pathdependent valvetrain technologies includi ng variations of Variable Valve Timing (VVT), Variable Valve Lift (VVL) and cylinde r deactivation that are tailored to either SOHC or DOHC engines. This separation also allowed for a more accurate method of accounting for net cost and effectiveness compared to the NPRM. For both the SOHC and DOHC paths, VVL technologies were m oved upstream of cylinder deactivation in response to comments from the Alliance, additional confidential manufacturer comments and submitted product plan trends , and NHTSA’s analysis. Confidential comments stated that applying cylinder d eactivation to an OHC engine is more complex and expensive than applying it to an OHV engine. The Alliance additionally stated that cylinder deactivation is very a pplication-dependent, and is more effective when applied to vehicles with high power-t o-weight ratios. Taking in account the application-specific nature of cylinder deactivation and th e fact the VVL technologies are more suitable to a broader range of applications, NHTSA moved VVL technologies “upstream” of cylinder deact ivation on the SOHC and DOHC to more accurately represent how a manufactu rer might apply these technologies.V-31

Figure V-8. Engine Technology (EngMod) Decision TreeV-32

On the OHV path, the ordering of cylinde r deactivation (DEACO) then Coupled Cam Phasing (CCPO), which is opposite the or der of the SOHC and DOHC paths, was retained as defined in the NPRM. This ordering depicts most accurately how manufacturers would actually implement thes e technologies and was reflected in the submitted product plans for OHV engines, which are largely used on trucks with high power-to-weight ratios. Af ter the application of CCPO on the OHV decision tree, the
model chooses between Discrete Variable Valve Lift (DVVLO) a nd the conversion to a dual overhead camshaft engine (CDOHC). This conversion now includes Dual Cam Phasing (DCP) instead of Continuously Vari able Valve Lift (CVVL) because it is assumed that DCP, with its higher applicati on rates, would more likely be applied than CVVL, with its lower applic ation rates.

At this stage, and similar to the NPRM , the decision tree paths all converge into
Stoichiometric Gasoline Dir ect Injection (SGDI). All pr eviously applied technologies are retained with the assumption that SGDI is applied in addition to the pre-existing engine technologies. After SGDI, a ne wly defined technology, Combustion Restart (CBRST), has been added.

The “branch point” after CBRST has been lim ited to two paths instead of the three paths in NPRM. This is due to the removal of HCCI from the fina l rule decision trees. The final rule engine decision tree allowed the model to apply either Turbocharging and Downsizing (TRBDS) or the conversion to diesel (DSLC). TRBDS is considered to be a completely new engine that ha s been converted to DOHC, if not already converted, with only LUB, EFR, DCP, SGDI and CBRST applied.

The conversion to diesel is also consider ed to be a completely new engine that replaces the gasoline engine (although it carries over the LUB and EFR technologies).
If the model chooses to follow the TRBD S path, the next t echnology that can be applied is another newly-added technol ogy, EGR Boost (EGRB). After EGRB, the model is allowed to then convert the engine to diesel (DSLT). It should be noted that the path-dependent variations of diesel, (DSLC) and (DSLT) , result in the exact same technology. The net cost and effectivene ss estimates are the same for both but
DSLT’s incremental cost and effectiveness es timates are slightly lower to account for the TRBDS and EGRB technologies th at have already been applied.

Electrification/Accessory T echnology Decision Tree This path, shown in Figure V-9, was named simply “Accessory Technology” in the NPRM. Electric Power Steering (EPS) is now the first technology in this decision tree, since it is a primary enabler for both mild and strong hybrids. Improved Accessories (IACC) has been redefined to include only an intelligent cooling system and follows EPS (in the NPRM, IACC was the first technology in the tree). The 42-volt Electrical System (42V) technology has been removed because it is no longer viewed as the voltage of choice by manufactures and is being replaced by higher voltage systems. Micro-Hybrid (MHEV), which follows IACC, has been adde d as a 12-volt stop/start system to replace Integrated Starter/Generator with Idle-Off (ISGO), which was on the “Transmission/Hybrid Technology” decision tree in the NPRM. Higher Voltage /V-33

Improved Alternator (HVIA), a higher efficien cy alternator that can incorporate higher voltages (greater than 42V) follows MHEV. Integrated Starter Generator Hybrid (ISG) replaced IMA/ISAD/BSG Hybrid (which was also on the Transmission/Hybrid Technology decision tree in the NPRM) as a hi gher voltage hybrid system with limited regenerative capability. ISG takes in to account all the previously applied Electrification/Accessory technologies and is th e final step necessary in order to convert the vehicle to a (full) strong hybrid. All Electrification/A ccessory technologies can be applied to both automatic and manual transmission vehicles.

Transmission Technology Decision Tree This decision tree, shown in Figure V-9, contains two paths: one for automatic
transmissions and one for manual transmissions . On the automatic path, the Aggressive Shift Logic (ASL) and Early Torque Convert er Lockup (TORQ) technologies from the NPRM have been combined into an Improve d Auto Trans Controls/Externals (IATC) technology, as both these techno logies typically include onl y software or calibrationrelated transmission modificati ons. This technology was move d to the top of the decision
tree since it was deemed to be easier and less expensive to implement than a major redesign of the existing transmission. Th e 5-Speed Automatic Transmission (5SP) technology from the NPRM has been deleted du e to several factors. First, the updated decision tree logic seeks to optimize the curren t hardware as an initial step, instead of applying an expensive redesign technology. Second, NHTSA determined an industry trend of 4-speed automatics going directly to 6-speed automatics, as reflected in the submitted product plans. And finally, confiden tial manufacturer comments indicated that in some cases 5-speed transmissions offere d little or no fuel economy improvement over 4-speed transmissions (primarily due to highe r internal mechanical and hydraulic losses, and increased rotating mass), making the te chnology less attractive from a cost and effectiveness perspective. In the fina l rule, both 4-speed a nd 5-speed automatic transmissions get the IATC t echnology applied first, before progressing through the rest
of the transmission decision tree.

After IATC the decision tr ee splits into a “Unibody only” and “Unibody or Ladder Frame” paths, which is identical to the NRPM version of the decision tree. Both of these paths represent a conversion to new and fully optimized designs. The Unibody only path contains the Continuously Variable Transm ission (CVT) technology, while the Unibody or Ladder Frame path has the 6-Speed Au tomatic Transmission (6SP) technology being replaced by 6/7/8-Speed Automatic Transm ission with Improved Internals (NAUTO). The NAUTO technology represents a new generation of automa tics with lower internal losses from gears and hydraulic systems.

The NPRM technology “Automated Manual Tr ansmission (AMT)” has been renamed
Dual Clutch Transmission/Automated Manual Transmission (DCTAM) to more accurately reflect the true intent of this technology to be a Dual Clutch Transmission (DCT). The NPRM’s use of the abbreviation “AMT” was confusing to many commenters, including the Alliance, BorgWarner, Chrysler, Ford and General Motors, and appeared to indicate that the NPRM analysis applied true automated manual transmissions, which exhibit a torque interr upt characteristic that many in the industryV-34

feel will not be customer acceptable. DCT doe s not have the torque interrupt concern. The technology DCTAM for the final rule assu mes the use of a DCT type transmission only.

The manual transmission path only has one technology applica tion, like the NPRM. However, the technology being applied has been defined as conve rsion to a 6-Speed Manual with Improved Internals (6MAN) in stead of a conversion to a 6/7/8-Speed
Manual Transmission as defined in the NR PM. Extremely limited use of manual transmissions with more than 6 speeds is in dicated in the updated product plans, so
NHTSA believes this is a more accurate option for replacing a 4 or 5-speed manual
transmission.

Hybrid Technology Decision Tree The strong hybrid options, 2-Mode (2MHEV) and Power Split (PSHEV), are no longer sequential as defined in the NPRM’s Transm ission/Hybrid decision tree. For the final rule, the model only applies strong h ybrid technologies when both the Electrification/Accessory and Transmission (aut omatic transmissions only) technologies have been fully added to the vehicle, as seen in Figure V-9. The final rule analysis and logic ensures that the model does not double-count the cost and effectiveness estimates for previously applied technologies that are included ( e.g. , EPS) or replaced ( e.g. , transmission) by strong hybrid systems, whic h is responsive to General Motors’ comment stating that the NPRM analysis had the poten tial to double-count effectiveness estimates when applying strong hybrids. For the final rule analysis, when the Volpe model applies strong hybrids it now takes into account that some of the fuel consumption reductions have already been accounted for when technologies like EPS or IACC have been previously applied. Once all the Elec trification/Accessory and Transmission technologies have been applie d, the model is allowed to c hoose between the application of 2MHEV, PSHEV and the newly added Plug- in Hybrid Vehicle (PHEV). The NPRM decision tree required the Volpe model to step through 2MHEV in order to apply PSHEV. This updated final rule decision tree is a more real istic representation of how manufacturers might apply strong hybrids, and allows the Volpe model to choose the strong hybrid that is most appropriate for each vehicle based on its vehicle subclass or the most cost-effective technology application. The PHEV technology was added to the
decision tree in the final rule based upon information in the public domain and submitted product plans showing that limited quantities of these vehicles will be available from
some manufacturers in this timeframe.V-35

Figure V-9. Electrification/Accessory, Tr ansmission and Hybrid Technology
Decision Tree

Vehicle Technology Decision Tree Material Substitution (MS1), (MS2) and (MS5) are now located on dedicated material substitution path in the Vehicle Technology Decision Tree, shown in Figure V-10. Low Rolling Resistance Tires (ROLL), Low Drag Brakes (LDB) and Secondary Axle Disconnect (SAX) now reside as a separate path, due to the relocation of material substitution technologies. Secondary Axle Di sconnect has been redefined for the final rule to apply to 4WD vehicles only to more accu rately reflect feasible applications of this technology. Aerodynamic Drag Re duction (AERO) remains a se parate tree, and is now a 10 percent reduction for both car and truck classes (excludi ng performance cars, which are exempt).V-36

Figure V-10. Vehicle Technology Decision TreeV-37

4. Division of vehicles into subclasses based on technology applicability, cost and effectiveness In assessing the feasibility of technologies under consideration, th e agency evaluated whether each of these technologies could be implemented on all types and sizes of
vehicles and whether some differentiation is necessary with respect to the potential to apply certain technologies to ce rtain types and sizes of vehicl es, and with respect to the cost incurred and fuel consumption ach ieved when doing so. The 2002 NAS Report differentiated technology applica tion using ten vehicle classes (4 cars classes and 6 truck classes, including subcompact cars, compact cars, midsize cars, large cars, small SUVs, midsize SUVs, large SUVs, small pickups, la rge pickups, and minivans), but did not
determine how cost and effectiveness values differ from “class” to “class.” NAS’s purpose in separating vehicles into these “classes” was to create groups of “like” vehicles, i.e., vehicles similar in size, pow ertrain configuration, weight, and consumer use, and for which similar technologies are a pplicable. This vehicle differentiation is done solely for the purpose of applying tec hnologies to vehicles and assessing their incremental costs and effectiveness, and s hould not be confused with, the regulatory classifications pursuant to 49 CFR Pa rt 523 discussed in Chapter XI.

The Volpe model, which NHTSA has used to perform analysis supporting today’s notice,
divides the vehicle fleet into subclasses based on model i nputs, and applies subclassspecific estimates, also from model inputs, of the applicability, cost , and effectiveness of each fuel-saving technology. Therefore, the m odel’s estimates of the cost to improve the fuel economy of each vehicle model depend upon the subclass to which the vehicle model is assigned.

In its MY 2005-2007 and MY 2008-2011 light truc k CAFE standards as well as NPRM, NHTSA performed analysis using the same vehicle classes defined by NAS in its 2002 Report. In its 2008 NPRM for MY 2011-2015, NHT SA included some differentiation in
cost and effectiveness numbers between the va rious classes to account for differences in technology costs and effectivene ss that are observed when technologies are applied on to
different classes and subclasses of vehicles. The agency found it important to make that differentiation because the agency estimated th at, for example, engine turbocharging and downsizing would have different implications for large vehicles than for smaller vehicles. For the final rule, NHTSA, working with Ricardo, increased the accuracy of its technology assumptions by reexaming the s ubclasses developed for the purpose of modeling technology application and by providing more differen tiation in the costs and
effectiveness values by vehicle subclass.

In the request for comments accompanying the NPRM, NHTSA asked manufacturers to identify the style of each vehicles model th ey submit in their product plans from eight possible groupings (convertible, coupe, ha tchback, pickup, sedan, sport utility, van, or wagon) or sixteen possible market segments (cargo van, compact car, large car, large pickup, large station wagon, mids ize car, midsize station wa gon, mini-compact, minivan, passenger van, small pickup, small station wa gon, special purpose, sport utility truck, subcompact car, and two-seat car). NHTSA al so requested that manufacturers identify many specific characteristics rele vant to each vehicle model, such as the number ofV-38

cylinders of the vehicle’s engine and other engine, transmission and vehicle
characteristics. This information was ev aluated by NHTSA staff, entered in NHTSA’s market data file, and used by NHTSA to assess how to divide the vehicles into subclasses for purposes of differentiating the applicability, effectiveness, and cost of available technologies.

In response to the NPRM, the Alliance comm ented that NHTSA’s classification approach is not robust enough. With regard to subclass es of cars, the Allianc e stated that NHTSA did not distinguish high-performance and s ports cars which cannot accommodate certain technologies without changing the purpose and co nfiguration of the vehicle. With regard to subclasses of trucks, the Alliance argued th at SUVs were not adequately distinguished by size. The Alliance further stated the classification used by Sierra Research in its report to distinguish groups of like vehicles for technol ogy application purposes was more realistic and representative of diffe rences in market segments than NHTSA’s classification. The Alliance suggested that NHTSA consider the classes identified by
Sierra Research in the final rule.

NHTSA is not adopting Sierra’s approach to classification for the following reasons. First, Sierra’s classification scheme is t oo dependent on vehicle characteristics for which NHTSA often did not receive complete inform ation from manufacturers. For example, although NHTSA requested that manufacturer s provide estimates of the aerodynamic drag coefficient of each vehicle model planned for MY2011-2015, the agency received no estimates for many vehicles. NHTSA be lieves manufacturers are too far from production on many vehicles to confidently provide such estimates. Second, Sierra’s classification scheme is, for NHTSA’s purpos es, excessively fine-grained. Sierra’s analysis relied on 25 subclasses in total, 13 fo r cars and 12 for trucks. While their report provided tables comparing their classes to those of NHTSA’s and cited product examples for each class, it did not provide a reason fo r why this detailed differentiation would significantly improve the outcome . NHTSA’s review of the Si erra report did not reveal many differences in technology- application between these s ubclasses. In addition, the agency does not believe that the effort required by the agency to create a more detailed yet more complex modeling structure based on 25 subclasses would result in significant improvement in the accuracy of the results . Sierra may have found this additional differentiation important for the full vehicl e simulation approach that the Alliance claimed should be used throughout NHTSA’s an alysis. However, as discussed below, NHTSA has concluded that this approach is neither necessary nor practical for CAFE analysis.

The agency agrees with the Alliance, however, that some refinement in the classification approach used by NHTSA in the NPRM is merite d in order to ensure the practicability of technologies being added. The agency also believes that the limited differentiation in costs and effectiveness values by vehicle clas s needs to be expande d in order to better account for fuel savings and costs.

For the final rule, NHTSA first reexamined the Volpe model technology output files from the NPRM to identify where and why technologies may have been inappropriatelyV-39

applied by the model. Where this reexamina tion revealed logical e rrors, the Volpe model was revised accordingly. However, the revi ew revealed that most of the observed
inaccuracies resulted from the manner in whic h vehicles were assigned to subclasses for the purpose of technology applic ations. NHTSA also reviewed the confidential vehicle
level information received from manufactur ers, how manufacturers classified their vehicles by style or market segment groupi ngs requested by NHTSA and the specific engine, transmission and other vehicle charac teristics identified by the manufacturers for
each vehicle model. This conclusion was among those that led NHTSA to assign more staff to perform quality control when review ing and integrating manufacturers’ product plans.

In order to improve the accuracy of tec hnology application modeling, NHTSA examined at the car and truck segments separately. Fi rst, for the car segment, NHTSA plotted the footprint distribution of vehicl es in the product plans and di vided that distribution into four equivalent footprint range segments. The footprint ranges were named Subcompact, Compact, Midsize, and Large classes in ascendi ng order. Cars were then assigned to one of these classes based on their specific footpr int size. Vehicles in each range were then manually reviewed by NHTSA staff to evaluate and confirm that they represented a fairly reasonable homogeneity of size, weight, powertrains, consumer use, etc. However, as the Alliance pointed out, some vehicles in each group were sports or high-performance models. Since different technologies and cost and effectiveness estimates are appropriate for these vehicles, NHTSA created a perfor mance subclass within each car class to maximize the accuracy of technology application. To determine which cars would be assigned to the performance subclasses, NHTSA graphed (in ascending rank order) the power-to-weight ratio for each vehicle in a cl ass. An example of the Compact subclass plot is shown below. The subpopulation was then manually reviewed by NHTSA staff to determine an appropriate transition point between “performance” and “non-performance”
models within each class.

Compact Subclass - P/W Ratio in Ascending Order

0 0.02 0.04 0.06 0.08

0.1 0.12 0.14 0.16 0.18

0.2Power (HP) / Curb Wght. (Lbs) Compact

Transition Area

High Perf. Normal Perf.V-40

A total of eight classes (including performa nce subclasses) were identified for the car segment: Subcompact, Subcompact Performance, Compact, Compact Performance, Midsize, Midsize Performance, Large, Large Performance. In total, the number of cars that were ultimately assigned to a performa nce subclass was less th an 10 percent. The
table below shows the difference in the clas sification between the NPRM and Final Rule and provides examples of the type s of vehicles assigned to each.

NPRM Car Subclasses Class Example vehicles Subcompact Chevy Aveo, Chevy Corvette, Ford Mustang (V8), Honda Civic, Mazda Miata, Saturn Sky Compact Audi S4 Quattro, Chevy Camaro (V6), Chevy Cobalt, Daimler CL600, Mazda RX8, Nissan
Sentra
Midsize Bentley Arnage, Cadillac CTS, Honda Accord, Nissan Altima & G37 Coupe, Toyota Camry Large Audi A8, Cadillac DTS, Hyundai Azera

Final Rule Car Subclasses Class Example vehicles Subcompact Chevy Aveo, Honda Civic Subcompact Performance Mazda Miata, Saturn Sky Compact Chevy Cobalt, Nissan Sentra and Altima Compact Performance Audi S4 Quattro, Mazda RX8
Midsize Chevy Camaro (V6), Toyota Camry, Honda Accord, Hyundai Azera
Midsize Performance Chevy Corvette, Ford Mustang (V8), Nissan G37 Coupe Large Audi A8, Cadillac CTS and DTS Large Performance Bentley Arnage, Daimler CL600

For light trucks, in reviewing the upda ted manufacturer product plans and in reconsidering how to divide trucks into classes and subclasses based on technology applicability, NHTSA found less of a distinction between S UVs and pickup trucks than appeared to exist in earlier rulemakings. Manufacturers appear to be planning fewer ladder-frame and more unibody pickups, and many pickups will share common powertrains with SUVs. Consequently, NHT SA condensed the classes available to trucks, such that SUVs and pickups are no longer divided. Re cognizing structural differences between various types of “V ans,” NHTSA revisited how it assigned thedifferent types of “Vans.” Instead of merging minivans, cargo vans, utility and multipassenger type vans under the same class, as it did for the NPRM and in previous rules, NHTSA formed a separate minivan class, because minivans ( e.g. , the Honda Odyssey) are expected to remain closer in terms of st ructural and other engi neering characteristicsV-41

than vans (e.g. , Ford’s E-Series—also known as Econoline—vans) intended for more passengers and/or heavier cargo.

The remaining vehicles (other vans, pickups, and SUVs) were then segregated into three footprint ranges and assigne d a class of Small Truck/SUV, Midsize Truck/SUV, and Large Truck/SUV based on their footprints. NHTSA staff then manually reviewed each population for inconsistent vehicles based on engine cylinder count, weight (curb and/or gross), or intended usage, since these ar e important considerations for technology application, and reassigned vehi cles to classes as appropriate . This system produced four truck segment classes—minivans and small, medium, and large SUVs/Pickups/Vans. The
table below shows the difference in the clas sification between the NPRM and Final Rule
NPRM Truck Subclasses Class Example vehicles

Minivans Dodge Caravan, Ford Econoline, Toyota Sienna
Small Truck Chevy Colorado, Toyota Tacoma, Ford Ranger Large Truck Chevy Silverado
Small SUV Ford Escape, Nissan Rouge
Midsize SUV Jeep Wrangler 4-door, Volvo XC70 Large SUV Toyota Sequoia

Final Rule Truck Subclasses Class Example vehicles

Minivans Dodge Caravan, Toyota Sienna
Small SUV/Pickup/Van Ford Escape & Ranger, Nissan Rogue,

Midsize SUV/Pickup/Van Chevy Colorado, Jeep Wrangler 4-door, Volvo XC70, Toyota Tacoma Large SUV/Pickup/Van Chevy Silverado, Ford Econoline, Toyota Sequoia

Based on a close review of detailed output from the Volpe model, NHTSA has concluded
that its revised classifica tion for purposes of technology applicability substantially improves the overall accuracy of the results as compared to the system employed in the NPRM. The new method uses footprint as a first indicator for bot h the car and truck segments, and all are then manually reviewed for the types of technologies applicable to them and revised by NHTSA to ensure that they have been properly assigned. The addition of the performance subclasses in th e car segment and the condensing of classes in the truck segment further refine the syst em. The new method increases the accuracy of technology application without overly complicat ing the Volpe modeling process, and the revisions address comments received in response to the NPRM.

5. How did NHTSA develop technology cost and effectiveness estimates for the
final rule?V-42

In the NPRM, NHTSA employed technology cost and effectiveness estimates developed in consultation with EPA. They represente d NHTSA and EPA staff’s best assessment of the costs for each technology considered base d on the available public and confidential information and data sources that the agen cies had back in 2007 when the rulemaking was initiated. EPA also published a repor t and submitted it to the NRC committee on fuel economy of light-duty vehicles. 109

Public comments on the NPRM’s technology cost estimates generally fell into four categories: (1) that costs are underestimat ed because NHTSA did not account for all changes/costs required to apply a technology or because although NHTSA correctly identified all the changes requi red, it did not cost those ch anges appropriately; (2) that
costs are underestimated because the Retail Price Equivalent (RPE) factors have been applied incorrectly to technol ogies; (3) that costs are eith er over- or underestimated because learning curves have been applied in correctly to technologies ; and (4) that cost assumptions are overly simplified as applied to the full range of fleet vehicles and do not properly account for the differences in cost impacts across vehicle and engine types ( e.g. , technologies applied to a sub-compact car will be unique to those same technologies applied to a large SUV). Many commenters also stated that they found it difficult to
understand how NHTSA and EPA had derived the cost estimates. In addition to commenting on NHTSA’s methodology, many commen ters, particularly manufacturers,
also submitted their own cost estimates for each technology and requested that NHTSA
consider them for the final rule.

As explained above, NHTSA contracted with Ri cardo to aid the agency in analyzing the comments on the technology assumptions used in the NPRM, and relied considerably on Ricardo’s expertise in developi ng the final technology cost and effectiveness estimates based on that analysis. For every tec hnology included in NHTSA’s analysis of technology costs and effectiveness, Ricar do and NHTSA engineers reviewed the comments thoroughly and exercised their expe rtise in assessing the merits of the comments, and in resolving the differences and determining which estimates should be
used for the final rule.

For each technology, NHTSA relied on Ricardo’s experience with “bill of materials” (BOM) costing. Some commenters criticized NHTSA for not using a BOM as the basis for its cost analysis. The 2008 Martec report, 110 which updated the Martec report on which the 2004 NESCCAF study was based, was submitted by auto industry commenters to NHTSA’s NPRM docket for the agency’s consideration. This report provides cost estimates developed on a “bill of materi als” basis and met hodology. NHTSA, with Ricardo’s assistance, reviewed the “bill of ma terials” methodology in the Martec report and found it to be, compared to the methodol ogy used in the NPRM, a more defensible and transparent basis for evaluating the costs of applicable technologies.

109 EPA Staff Technical Report: Cost and Effectiven ess Estimates of Technologies Used to Reduce LightDuty Vehicle Carbon Dioxide Emissions. EPA420-R-08-008, March 2008.

110 Martec, “Variable Costs of Fuel Economy Technologies,” June 1, 2008.V-43

A bill of materials in a general sense is a list of components that make up a system—in this case, an item of fuel economy-improving technology. In order to determine what a system costs, one of the first steps is to de termine its components and what they cost. In cases in which it was not practicable for the agency and Ricardo to estimate the cost of each component on a BOM basis because there was a shift to a more advanced technology and or because of difficulty in ac counting for the sum of costs of all added components less the sum of cost s of all deleted components ( e.g. , in the transition from a gas engine to a diesel engine), incremental costs were estimated to be those of the entire new technology platform (in this example, the diesel engine) less those of the entire old technology platform (in this example, the gas engine). This “net difference” process was only used where developing a ground-up de scription of all component changes necessitated by the incremental technology was deemed to be impracticable.

With that framework in mind, Ricardo and NHT SA engineers proceeded with reviewing cost information for each major component of each technology. They compared the multiple sources available in the docket and assessed their validity. While NHTSA and Ricardo engineers relied considerably on the 200 8 Martec Report for costing contents of some technologies, they did not do so for all. When relevant publicly available information and data sets, including the 2008 Martec report, were determined to be incomplete or non-existent, NHTSA looked to prior published data, including the NPRM, or to values provided to NHTSA by commenter s familiar with the material costs of the described technologies.

Generally, whenever cost information fo r a technology component existed in a nonconfidential and publicly avai lable report submitted to the NPRM docket and that information agreed with Ricardo’s independe nt review of cost estimates based on
Ricardo’s historical institutio nal knowledge, Ricardo and NHTSA cited that information.
Ricardo and NHTSA were able to take that approach freque ntly, as is evident in the explanation of the cost figures of each technology. When that approach was not possible,
but there was confidential manufacturer data that had been submitted to NHTSA in response to the NPRM, and those costs were consistent with Ricardo’s independentlyreviewed cost estimates, NHTSA and Ri cardo cited those data. When multiple
confidential data sources diffe red greatly and conflicted with the Martec valuation or when the technical assumptions described by NHTSA for purposes of this rulemaking did not match exactly with the content costed by either Martec or other commenters, NHTSA and Ricardo engineers used component-level data to build up a partial cost, substituting Ricardo’s institutional knowledge for the remaining gaps in component level data.

Occasionally, NHTSA and Ricardo found that some cost information submitted by the public was either not very clearly described or revealed a lack of knowledge on the part of the commenter about NHTSA’s methodology. In those cases, and in cases for which no cost data (either public or confidential) was available, NHTSA worked with Ricardo either to confirm the estimates it used in the NPRM, or to revise and update them.V-44

In several cases, values described in the NP RM were simply adjusted from 2006 dollars to 2007 dollars, using a ratio of GDP valu es for the associated calendar years. 111 In many instances, an RPE factor of 1.5 was determined to have been omitted from the cost estimates provided in the NPRM, so NHTSA applied the multiplier where necessary to calculate the price to the consumer.

Finally, in response to comments stating that cost estimates for individual technologies should be varied, based on the type and size of vehicle to which they are applied, NHTSA
worked with Ricardo to account for that. Addi tionally, application of some technologies might be more or less expensive, depending on content ( e.g. , with or without a noise attenuation package), for particular vehi cles. In these cases, NHTSA and Ricardo described a range of costs for this technology, and referred to sources that indicate the appropriate boundaries of that range.

The agency notes that several technologies cons idered in the final rule have been updated with substantially different cost estimates re lative to those costs described in the NPRM. For example, RPE estimates for turboc harging and downsizing (TRBDS), diesel technologies (DSLT) and hybrid technologies (like IS G) are much higher than the costs cited in the NPRM for those technologies. Th is is due in large pa rt to the updated cost estimates of the 2008 Martec Report and others, referenced in the final rule, which reflect the dramatic rise of global costs for raw materials associated with the above technologies since the 2004 Martec report and ot her prior referenced cost estimates were conducted. The NPRM costs were not updated to reflect that rise in commodities prices. As described in the 2008 Martec Report, adva nced battery technologi es with substantial copper, nickel or lithium content, and engine technologies employing high temperature steels or catalysts with consid erable platinum group metals usage, have experienced tremendous inflation of raw material prices since the cost studies referenced
in the NPRM were conducted. As of the time the sources were developed, prices of nickel, platinum, lithium, copper, dysprosium and rhodium had demonstrated cost inflation amounting to between 300 and 750 percen t of global prices at the time of the original NESCCAF study 112 and this is reflected in the higher costs descri bed in the 2008 Martec report, and thus in the final rule. NHTSA is aware that commodity prices, like those for steel and platinum group metals described above, have dropped over the last several months. However, there is little information in the record to determine how prices of components used in MY 2011 could be impacted by the prices of metals and other commodities over the last few years. It is not clear wh ether the prices of components built and used in MY 2011 are mo re likely to reflect the high price of commodities in the years prior to 2008, the curr ent low prices of commodities, the prices of commodities closer to MY 2011, or some mi xture of these. The agency notes, though, as mentioned above, that manufacturers’ product plans were submitted along with manufacturers’ indications that these plans we re generally informed by expectations that relatively high commodity prices would prev ail in the future. Therefore, in the expectation that economic conditions will im prove by MY 2011, the agency relies on the

111 NHTSA examined the use of the CPI multiplier instead of GDP for adjusting these dollar values, but found the difference to be exceedingly small – only $0.14 over $100.

112 2008 Martec report, at 13-20.V-45

commodity prices reflected in, for exampl e, the 2008 Martec report. However, the agency further notes that these decisions are limited to the MY 2011 rulemaking. We intend to monitor commodity prices carefully and will adjust affected technology costs as appropriate in future rulemakings.

Some commenters referenced the price differential between vehicles with advanced technologies and more standard versions as evidence of those advanced technologies’ costs, and argued that NHTSA should consider these price differentials in its cost estimation process. In response, NHTSA be lieves that the “bottom-up, material cost based” cost estimation methodology employed for the final rule is preferable to estimating costs based on manufacturer price differentials between versions of vehicle models. Wherever possible, technologies were costed based on the es timation of variable material cost impacts to vehicle manufactur ers at a fixed point in time (in 2007 dollar terms) for a prescribed set of component changes anticipated to be required in implementing the technology on a particular platform ( e.g. , wastegate turbo, increased high nickel alloyed exhaust manifolds, air ch arge cooler, etc. for TRBDS). The content assumptions are modified or scaled to account for differences across the range of vehicle sizes and functional requirements and associat ed material cost impacts are adjusted to
account for the revised content. The material cost impacts to the vehicle manufacturers are then summed and converted to retail pr ice equivalent impacts by multiplying by 1.5
to account for fixed costs and other overhead s incurred in the implementation of new vehicle technologies but not contained in th e variable material price impacts to the
manufacturers.

In employing this methodology, NHTSA relied on information provided to NHTSA by the suppliers and vehicle manufacturers th emselves. Though this estimation process relies on often confidential data and empl oys a simplifying assumption in relating all
variable material costs to retail impacts through the use of a consistent 1.5 RPE, the methodology is preferable to a “top-down, retail price base d” methodology as might be used by comparing retail price differences of vehicles with different technologies. The “bottom-up” approach offers the benefits of providing a consistent and reasonable assessment of true, total costs for all technolog ies independent of geographic, or strategic pricing policies by vehicle manu facturers that could result in selling products at substandard or even negative margins. Fo r many vehicle manufacturers, contribution to corporate profit varies dramatically across vehi cle segment. Given that vehicle pricing is often decoupled from true costs and will vary with sales cycle, product maturity, geography, vehicle class, and marque, a “top -down” approach, while offering improved data transparency, is inherently limited in providing a consistent means of cost estimation. As such, NHTSA has adopted th e described “bottom-up” cost estimation approach and has attempted to mitigate transparency issues with a reliance on Martec 2008 (where in agreement with other provided co st data), because it provides a detailed description of the costed c ontent. Fundamentally, NHTSA believes that a “bottom-up” cost estimation methodology with a common RPE adjustment fact or offers an intuitive, consistent process across all technologies, wh ether mature or otherw ise, that avoids the pitfalls of reliance on significantly more variable and volatile pricing policies.V-46

Regarding estimates for technology effectiv eness, NHTSA, working with Ricardo, also
reexamined its NPRM estimates and t hose in the EPA Staff Technical Report, 113 which largely mirrored NHTSA’s NPRM estimates. We compared these estimates to estimates provided in comments, reports and confidentia l data received in response to our NPRM. Comments on the NPRM’s effectiveness estimates generally fell into three categories: (1) that NHTSA did not account sufficiently for fuel economy or performance impacts because it used the Volpe model approach rather than full vehicle simulation; (2) that the synergy values used did not properly account for technology inter actions; and (3) that
NHTSA made errors when usi ng estimates provided by manufacturers. In addition to commenting on NHTSA’s methodology, many commen ters, particularly manufacturers, also submitted their own fuel consumpti on reduction estimates for each technology and requested that NHTSA consider them for the final rule.

For each technology, NHTSA also relied on Ricardo’s experience with “bill of materials” (BOM) technology descriptions. Some commenters argued that the same BOM used as the basis for the cost analysis could and shoul d be used to define the technologies being studied for effectiveness. In fact, Rica rdo’s methodology for cost and effectiveness
estimates for this rule was to define a ve hicle class-specific BOM or BOMs, depending upon the number of variants possible within a class and within a decision tree. These BOMs were defined for the baseline configuration for each class and then for each incremental step in the decision tree. Us e of a consistently-defined BOM is very important to estimating the impacts of technol ogies accurately, as it helps to ensure that technologies are not applied to baseline vehicles that alr eady contain the technology (with the exception of items that ar e not well-defined such as aerodynamic drag reduction, reduced rolling resistance tires, weight re duction, and engine fr iction reduction.)

In defining these BOMs, Ricardo relied on its experience worki ng with industry over many years and its recent experience preparing the December 2007 study for EPA. Ricardo built on its vehicle simulation work for EPA to help NHTSA evaluate appropriate effectiveness values for individu al fuel-saving technologies. In considering the comments, NHTSA and Ricardo evaluated th e 10 “vehicle subclasses” used in the NPRM for applicability of t echnologies and determined that the cost and effectiveness estimates could be more accurate by revising th e “vehicle subclasses” as described above so that they better represented the parameters of the vehicles they included. This, in turn, enabled NHTSA and Ricardo to distinguish more clearly the differences in fuel consumption reduction occurring when a techno logy is added to different vehicles.

Then, with the BOM framework applied to mo re precisely-defined vehicle subclasses, NHTSA and Ricardo engineers reviewed effec tiveness information from multiple sources for each technology. Together, they compared the multiple sources available in the docket and assessed their validity, taking care to ensure that common BOM definitions and other vehicle attributes such as perfor mance, refinement, and drivability were not compromised.

113 EPA Staff Technical Report: Cost and Effectiven ess Estimates of Technologies Used to Reduce LightDuty Vehicle Carbon Dioxide Emissions. EPA420-R-08-008, March 2008.V-47

Generally, whenever relevant effectivene ss information for a technology component existed in a non-confidential and publicly-a vailable report submitted to the NPRM docket, and that information agreed with Ricardo’s independent review of estimates
based on Ricardo’s historical institutiona l knowledge, NHTSA and Ricardo cited that
information. NHTSA and Ricardo were able to take that approach frequently, as is evident in the explanation of the effectiven ess for each technology. When that approach was not possible, but there was confidential manufacturer data that had been submitted to NHTSA in response to the NPRM, and those values were consistent with Ricardo’s independently-reviewed estimates, NHTSA and Ricardo cited those data. When multiple confidential data sources differed greatly or when the technical assumptions described by NHTSA for purposes of this rulemaking did not match the content in cluded in Ricardo’s study for EPA or in other comments, NHTSA and Ricardo engineers relied on Ricardo’s experience and an understanding of the maxi mum theoretical losses that could be eliminated by particular technologies to build up an effectiveness estimate, substituting Ricardo’s institutional knowledge for the remaining gaps in data.

Occasionally, NHTSA and Ricardo found that some fuel consumption reduction information submitted by the public was either not very clearly described or revealed a lack of knowledge on the part of the co mmenter about NHTSA’ methodology. In those cases, and in cases for which no effectiveness data (either public or confidential) was available, NHTSA worked with Ricardo either to confirm the estimates it used in the NPRM, or to revise and enhance them. In other cases, the commenters appeared unsure
how to evaluate the data from the NPRM , and so NHTSA and Ricardo provided more detailed explanations on the proce ss used or the components involved.

In response to comments stating that estimat es for individual technologies should be varied based on the type and size of vehicl e to which they are applied, NHTSA worked
with Ricardo to account for those differences mostly through the refined vehicle subclass definitions. However, even after making these adjustments, there are still some classes that require spanning different engine architectures and perfor mance thresholds. Just as the application of some technologies might be more or less expensive, depending on content ( e.g. , with or without a noise attenua tion package), particular vehicle technologies may have more or less im pact between classes where maintaining equivalent performance led to a reduced effectiveness. In these cases, NHTSA and Ricardo described a range of effectiveness values for this tec hnology, and referred to sources that indicate the appr opriate boundaries of that range.

With Ricardo’s assistance, the technology cost and effectiveness es timates for the final rule were developed consistently, using this systematic approach. While NHTSA still believes that the ideal estimates for the final rule would be those that have been through a peer-reviewed process such as that used fo r the 2002 NAS Report, and will continue to work with NAS, as required by EISA, to upda te the technology cost and effectiveness estimates for subsequent CAFE rulemakings , this approach, combined with the BOM methodology for cost and effectiveness, expanded number and types of vehicle subclasses and the changes to the synergistic effects described belo w, not only help to address the concerns raised by commente rs, but also represent a considerableV-48

improvement in terms of accuracy and transp arency over the approach used to develop
the cost and effectiveness estimates in the NPRM.

6. Learning curves As explained in the NPRM, historically NHTSA did not explicitly account for the cost reductions a manufacturer might realize th rough learning achieved from experience in actually applying a technology. However, base d on its work with EPA, in the NPRM NHTSA employed a learning factor for cer tain newer, emerging 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. The NPRM implemented technology learning cu rves 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 cumu lative production volume (usually referred to as the “learning rate”); a nd (3) the initial cost of th e technology. The majority of technologies considered in the NPRM did not have learning cost reductions applied to
them.

NHTSA assumed that learning-based reductions in technology costs occur at the point that a manufacturer applies the given technol ogy to the first 25,000 car s or trucks, and are repeated a second time as it produces anot her 25,000 cars or trucks for the second learning step. 114 NHTSA explained that the volumes chosen represented the agency’s best estimate for where learning would occur, and that they were better suited to NHTSA’s analysis than using a single number for the learning curve factor, because each manufacturer would implement technologies at its own pace in the rule, rather than assuming that all manufacturers implement identical technology at the same time.

NHTSA further assumed that after having produc ed 25,000 cars or trucks with a specific part or system, sufficient lear ning will have taken place such that costs will be lower by 20 percent for some technologies and 10 per cent for others. For those technologies, NHTSA additionally assumed that another cost reduction would be realized after another 25,000 units. If a technology was already in widespread use ( e.g. , on the order of several million units per year) or expected to be so by the MY 2011-2012 time frame, NHTSA assumed that the technology was “learned out,” and that no more cost reductions were
available for additional volume increases. If a technology was not estimated to be available until later in the rulemaking pe riod at that time, like MY 2014-2015, NHTSA did not apply learning for thos e technologies until those model years. Most of the technologies for which learning was applie d after MY 2014 were adopted from the 2004 NESCCAF study, which was completed by Martec . Whenever source data, like the 2004 NESCCAF study, indicated that manufacturer cost reduction from future learning would occur, NHTSA took that information into account.

Comments received regarding NHT SA’s approach to technology cost reductions due to manufacturer learning generally disagreed with the agency’s method. The Alliance, AIAM, Honda, GM, and Chrysler all commented that NHTSA had substantially

114 NHTSA treated car and truck volumes separa tely for determining those sales volumes.V-49

overestimated, and essentially “double-count ed,” learning effect s by applying learning reductions to component costs, specifically Martec estimates, which were already at high
volume. The Alliance submitted the 2008 Martec Report, which stated that NHTSA had “misstated” Martec’s approach to cost re ductions due to learning in the NPRM. As Martec explained, Martec did not ask suppliers to quote pri ces that would be valid for three years,
and Martec did not receive cost reductions from suppliers for some components in years two and three. Rather, industry res pondents were asked to establish mature component pricing on a forward basis gi ven the following conditions: at least three (3) manufacturers demanding 500,000 units per year and at least three (3) globally-capable suppliers available to supply the needs of each manufacturer. In no case did Martec ask industry responde nts to provide low volume, launch or transition costs for fuel consumption/CO 2 reducing technologies. Martec specifically designed the economic parameters in order to capture the effects of learning which is a reality in the low margin, high capital cost, high volume, highly competitive global automotive i ndustry. Applying additional reductions attributable to “learning” based on 25,000 unit improvements in cumulative volume after production launch (as desc ribed on pages 118-125 of the NHTSA NPRM) on top of Martec’s mature costs is an error. Martec’s costs are based on 1.5-2.0 equivalent modules of powertr ain capacity (500,000 units/year) so 25,000 unit incremental changes in cumulative production, as defined by NHTSA, will
have no effect on costs.

The 2008 Martec Report also stated that cu rrent industry practice consists of using competitive bidding based on long-term, high-volum e contracts that are negotiated before technology implementation decisions are made. Ma rtec stated that this practice considers the effects of volume, learning, and capital depr eciation. Martec also indicated that most of the technologies evaluated in the st udy are in high volume production in the global automotive industry today, and thus this forms a solid basis from which to estimate future

costs.

Honda also commented on NHTSA’s 25,000 unit (per manufacturer per year) volume threshold stating that, in their experience, costs were only likely to decrease due to learning at volumes exceeding about 300,000 uni ts per year per manufacturer. GM agreed, stating that suppliers do not respond t o, change processes, or change contract terms for relatively small volume changes like NHTSA’s 25,000 unit increment, thus volume changes of this magnitude have no effect on component pricing. GM also commented that its learning cycles are ba sed on time, not volume, and agreed with
Martec’s assessment that contracts with s uppliers typically specify volumes and costs over a period, which are usually equal to a pr oduct life cycle, a 4- to 5-year period.

Ford commented that base costs in the au tomotive industry are determined by a target setting process, where manuf acturers develop pricing with suppliers for a set period, and
manufacturers receive cost re ductions from the suppliers due to learning as time passes, apparently at a set amount year over year for several years. Ford also commented that NHTSA’s approach to learning curves had not accounted for current economic factors,V-50

like increases in commodity and energy prices, and cited the example of costs of batteries for hybrids and PHEVs which Ford stated “ar e not likely to depend solely on experience learned, but, to a large extent, on the additi onal energy and material costs they incur
relative to the vehicles w ithout the new technology.” Ford commented that NHTSA should account for these costs, and the factor of declining vehicle sales, in its learning curve approach.

BorgWarner, a components supplier, commented that learning-relate d costs savings are valid for technologies that “ start at low volume” (commenter’s emphasis). BorgWarner argued, however, that NHTSA’s assumed l earning curve would not apply to the technologies it supplies to manufacturers, 115 since these components are well-developed and in high volume use already, and are thus al ready “learned out.” BorgWarner further
commented that an increase in demand could in fact lead to higher prices if demand for raw materials exceeded supply.

UCS, in contrast, commented that NHTSA had not accounted for enough cost reductions due to learning. UCS stated that NHTSA should have provided “source data” for manufacturer-specific learning curves, and argued that NHTSA’s approach was “fundamentally flawed” for two primary r easons: first, because NHTSA had not
considered the fact that manufacturers e ngage in joint ventures to develop new technologies, and second, because manufact urers may also lear n from one another “through the standard practice of tearing dow n competitors’ products.” UCS argued that NHTSA’s learning-based cost reductions shoul d account for these methods of learning.
UCS further stated that NHTSA should not “treat[] car and truck sales volumes separately when estimating learning curves” be cause there may be much overlap in terms of technology application, esp ecially for vehicles like crossovers which may be either
cars or trucks. UCS conclude d that NHTSA should use EPA’ s suggested learning factor of 20 percent, citing EPA’s Staff Technical Report.

Public Citizen agreed that NHTSA should accoun t for economies of scale, but argued that
NHTSA should not have relied on initial cost estimates from industry, which the
commenter stated were “often overestimated.” Public Citizen cite d a 1997 briefing paper by the Economic Policy Institut e in support of this point, a nd argued that compliance cost
estimates were often much lower than actua l costs. Public Citizen concluded that NHTSA’s use of learning curve factors “imp edes transparency” in NHTSA’s analysis.

Agency response: Based on the comments received and on its work with Ricardo, NHTSA has revised its approach to accounting for technology cost reductions due to manufacturer learning. The me thod of learning used in the NPRM has been retained, but
the threshold volume has been revised a nd is now calculated on an industry-wide production basis. However, learning of th is type, which NHTSA now refers to as “volume-based” learning, is not appli cable to any technologies for MY 2011. Additionally, NHTSA has adopted a fixed rate , year-over-year (YOY) cost reduction for

115 BorgWarner manufacturers and supplies turbochargers, dual clutch transmissions, variable valve timing systems, diesel engine components (EGR and starting), aggressive shif t logic and early torque convertor lockup systems.V-51

widely-available, high-volume, mature technologies, in resp onse to comments from Ford and others. NHTSA refers to this type cost reduction as “time-based” learning. For each technology, if learning is applic able, only one type of learni ng would be applied, either volume-based or time-based ( i.e. , the types are independent of each other). These
revisions are discussed below.

For volume-based learning, NHTSA considered comments from UCS and decided to
revise the method used to calculate the thre shold volume from a per-manufacturer to an industry-wide production volume basis. NHTSA agreed with UCS’ comment that cars and trucks may share common components—this is true acr oss many makes and models which share common engines, transmissions , accessory systems, and mild or strong hybrid systems, all of which can potentially ut ilize the technologies under consideration. These systems are often manufactured by supplie rs who contract with multiple OEMs, all of whom benefit (in the form of cost reductions for the technology) from the supplier’s learning. The 2008 Martec Report and the Bo rgWarner comments additionally both
indicated that when manufacturers demand components in high volumes, suppliers are able to pass on learning-based savings to al l manufacturers with wh om they contract. Thus, it made sense to NHTSA to revise its method of determining whether the threshold volume has been achieved from an annual pe r-manufacturer to an annual industry-wide production volume basis.

NHTSA also changed the threshold volum e for volume-based learning from 25,000 to 300,000 units. The 2008 Martec Report and comments from multiple manufacturers indicated that 25,000 units was far too small a production volume to affect component costs. In response, NHTSA began with the Martec estimate that technologies were fully learned-out at 1.5 million units of production (which met the production needs of three manufacturers, according to that report). NHTSA then applied two cycles of learning in a
reverse direction to determine what the proper thres hold volume would be for these conditions. One cycle would be applied at 750,000 units (1.5 million divided by 2, which would represent the second volume doubli ng) and one at 375,000 units (750,000 divided by 2, which would represent the first volume dou bling). NHTSA thus estimated that the Martec analysis would suggest a thres hold volume of 375,000 units. However, the agency notes that Martec stated that it chose the 1.5 million units number specifically because Martec knew it was well beyond the poi nt where learning is a factor, which means that 1.5 million was beyond the cusp of the learning threshold. NHTSA therefore concluded that 375,000 units should represen t the upper bound for th e threshold volume for Martec’s analysis.

Having determined this, NHTSA sought to establish a lower bound for the threshold volume. The 2008 Martec report indicated that production efficiencies are maximized at 250,000-350,000 units (which averages to 300,0 00 units), and that manufacturers consequently target this range when pla nning and developing ma nufacturing operations. Honda also cited this produc tion volume. Thus, for thr ee manufacturers, the annual volume requirement would be 900,000 units. 116 NHTSA concluded this could also

116 An industry volume of 900,000 would imply a threshold volume of 225,000 units according to NHTSA’s analysis. This is still nine times the value used at the NPRM.V-52

represent high volume where learned costs could be available, and considered it as a lower bound estimate. With the upper and lo wer values established, and given that Martec specifically indicated that 1.5 million did not represent the cusp of the learning threshold, NHTSA chose the mid-point of 1.2 mi llion units as the best estimate of annual industry volumes where learned costs woul d be experienced. For proper forward learning, this would mean the first learni ng cycle would occur at 300,000 and the second at 600,000. Accordingly NHTSA has established the threshold volume for the final rule at 300,000 industry units per year.

Having established the threshold volume, NHTSA next considered which technologies to apply volume learning to. Comments confir med that NHTSA had been correct in the NPRM to assume that learning would be applicable to low-volume, emerging technologies that could benefit from ec onomies of scale, so NHTSA consulted confidential product plans to determine the volumes of technologies to be applied by manufacturers during the rule making period. If the product plans indicated that the technologies would be in high-volume use ( i.e. , above 600,000 units produced annually for cars and trucks by all manufact urers) at the beginning of its first year of availability, then volume-based learning was not considered applicable, since at this volume the technology would be available at learned cost. If the volume was below 600,000 units annually, then NHTSA also look ed at the Volpe model’s app lication of the technology. If the model applied more than 600,000 units w ithin the first year of availability, NHTSA did not apply volume-based learning. If ne ither manufacturers nor the model applied more than 600,000 units within the first year, then volume learning was applied to the technology.

Based on this analysis, NHTSA determined that volume-based learning would be applicable to three technologies for purposes of the final rule: integrated starter generator, 2-mode hybrid, a nd plug-in hybrid. For these three technologies, and where the agency’s initial co st estimates reflected full learni ng, NHTSA reverse-learned the cost by dividing the estimate by the learning rate twice to properly offset the learned cost estimate. NHTSA used a 20 percent learning rate in the NPRM for these technologies, and concluded that that rate was still applicab le for the final rule. This learning rate wasvalidated using manufacturer-submitted current and forecast cost data for advancedbattery hybrid vehicle technology, and accepted i ndustry forecasts for U.S. sales volumes of these same vehicles. This limited study indicated that cost efficiencies were approximately 20 percent for a doubling of U. S. market annual sales of a particular advanced battery technology, and the learning rate was thus used as a proxy for other advanced vehicle technologies.

Commenters also indicated that learning-rela ted cost reductions could occur not only as a result of production volume changes, but also as a function of time. For example, Ford stated that technology cost reductions were negotiated as part of the contractual agreement to purchase components from supp liers, a target-setting process which Ford
described as common in the automotive industr y. In this arrangement suppliers agree to reduce costs on a fixed percentage year over year according to negotiated terms. GM described a cost reduction pro cess that occurs over the cour se of a product life cycle,V-53

typically no less than 4-5 years, where co sts are reduced as production experience
increases. GM stated th at its cost reductions incl uded engineering, manufacturing, investment, and material costs, and were al so defined through s upplier contracts that anticipate volume and costs over the whol e period. The components involved are assumed to be high volume, mature tec hnologies being used in current vehicle production. These are the types of components that would typi cally be subject to “costdown” 117 efforts that target savings through small, incremental design, manufacturing, assembly, and material changes on a recurring or periodic basis.

In response to these comments, NHTSA has adopted this approach as an additional type of learning related cost reduc tion, referring to it as “time- based” learning. For purposes of the final rule, time-based learning is applied to high-volume, mature technologies likely to be purchased by OEMs on a long-term contractual basis. This would include most of the fuel-saving technologies unde r consideration, except those where volumebased learning is applied, or those wher e components might consist of commodity materials, such as oil or rubber, where pric ing fluctuations prevent long-term or fixed value contracts. NHTSA has used a 3 pe rcent reduction rate for time-based learning,
based on confidential manufacturer informa tion and NHTSA’s understanding of current industry practice. Thus, if time-based learning is deemed applicable, then in year two of a technology’s application, and in each subseque nt year (if any), the in itial cost is reduced by 3 percent. This approach is respon sive to comments about compliance costs estimation, and improves the accuracy of projecting future costs compared to the NPRM.

With regard to the comments from UCS, NHTSA recognizes that joint-venture collaboration and competitor tear-downs are methods used by manufacturers for designing and developing new pr oducts and components, but notes that these methods are used prior to the manufacturing stage, and t hus are not considered manufacturing costs. NHTSA has received no specific manufacturer learning curve-related data, and thus has
no “source data” to disclose. NHTSA continue s to use a 20 percent learning factor for volume-based learning, which is consistent with EPA’s learning factor recommended by
UCS for NHTSA’s use.

With regard to the comments from Public Citizen, although NHTSA reviewed the paper cited by the commenter, the agency found its analysis largely irre levant to NHTSA’s
estimation of cost reduction factors due to automobile manufacturer learning, and thus declines to adopt its findings.

Table V-4 below shows the applicability and ty pe of learning applied in the final rule.

117 Cost-down efforts are a common practice in competitive manufacturing environments like the automotive industry.V-54

Table V-4—Application of learning-relat ed cost reductions for technologies

Technology Abbr. Learning Type Learning

Rate

Low Friction Lubricants LUB Engine Friction Reduction EFR VVT - Coupled Cam Phasing (CCP) on SOHC CCPS TIME 3% Discrete Variable Valve Lift (DVVL) on SOHC DVVLS TIME 3% Cylinder Deactivation on SOHC DEACS TIME 3% VVT - Intake Cam Phasing (ICP) ICP TIME 3% VVT - Dual Cam Phasing (DCP) DCP TIME 3% Discrete Variable Valve Lift (DVVL) on DOHC DVVLD TIME 3% Continuously Variable Valve Lift (CVVL) CVVL TIME 3% Cylinder Deactivation on DOHC DEACD TIME 3% Cylinder Deactivation on OHV DEACO TIME 3% VVT - Coupled Cam Phasing (CCP) on OHV CCPO TIME 3% Discrete Variable Valve Lift (DVVL) on OHV DVVLO TIME 3%

Conversion to DOHC wi th DCP CDOHC TIME 3% Stoichiometric Gasoline Direct Injection (GDI) SGDI TIME 3%

Combustion Restart CBRST TIME 3% Turbocharging and Downsizing TRBDS TIME 3% Exhaust Gas Recirculation (EGR) Boost EGRB TIME 3% Conversion to Diesel following CBRST DSLC TIME 3% Conversion to Diesel following TRBDS DSLT TIME 3% Electric Power Steering EPS TIME 3% Improved Accessories IACC TIME 3% 12V Micro-Hybrid MHEV TIME 3% Higher Voltage/Improved Alternator HVIA TIME 3% Integrated Starter Generator ISG VOLUME 20% 6-Speed Manual/Improved Internals 6MAN TIME 3% Improved Auto. Trans. Controls/Externals IATC TIME 3% Continuously Variable Transmission CVT TIME 3% 6/7/8-Speed Auto. Trans with Improved Internals NAUTO TIME 3%

Dual Clutch or Automated Manual Transmission DCTAM TIME 3% Power Split Hybrid PSHEV TIME 3% 2-Mode Hybrid 2MHEV VOLUME 20% Plug-in Hybrid PHEV VOLUME 20% Material Substitution (1%) MS1 Material Substitution (2%) MS2 Material Substitution (5%) MS5 Low Rolling Resistance Tires ROLL Low Drag Brakes LDB TIME 3% Secondary Axle Disconnect – 4WD SAX TIME 3% Aero Drag Reduction AERO TIME 3%V-55

7. Technology synergies When two or more technologies are added to a particular vehicle model to improve its fuel efficiency, the resultant fuel consum ption reduction may sometimes be higher or lower than the product of the individual effectiveness values for those items. 118 This may occur because one or more technologies applie d to the same vehicle partially address the same source or sources of engine, drivetrain or vehicle losses. Alternately, this effect may be seen when one technology shifts th e 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 in dividual effectiveness values in that set is referred to for purposes of this rulemaking as a “synergy.” Synergies may be positive (increased fuel consumption reduction compared to the product of the individual effects) or negative (dec reased fuel consumption reduction).

For the NPRM, the Volpe model was modified to estimate the interactions of technologies using estimates of incremental synergies associated with a number of technology pairs identified by NHTSA. The us e of discrete technology pair incremental synergies is similar to that in DOE’s National Energy Modeling System (NEMS). 119 Inputs to the Volpe model incorporate NEMS-ide ntified pairs, as we ll as additional pairs for the final rule from the set of technologies considered in the Volpe model. However, to maintain an approach that was consiste nt with the technology sequencing developed by NHTSA, new incremental synergy estimates for all pairs were obtained from a first-order “lumped parameter” analysis tool created by EPA. 120

The lumped parameter tool is a spreadsheet model that represents energy consumption in terms 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 lo ss mechanisms using estimates of engine,
drivetrain and vehicle charac teristics that are averaged over the EPA fuel economy drive cycle. Results of this analys is were generally consistent w ith those of full-scale vehicle simulation modeling performed by Ricardo, Inc. However, regardless of a generally
consistent set of results for the vehicle cla ss and set of technologies studied, the lumped parameter tool is not a full vehicle simulati on and cannot replicate th e physics of such a

118 More specifically, the products of the differences between one and the technology-specific levels of effectiveness in reducing fuel consumption. For exam ple, not accounting for interactions, if technologies A and B are estimated to reduce fuel consumption by 10% (i.e., 0.1) and 20% (i.e., 0.2) respectively, the “product of the individual effectiveness values” would be 1 – 0.1 times 1 – 0.2, or 0.9 times 0.8, which equals 0.72, corresponding to a comb ined effectiveness of 28% rather than the 30% obtained by adding 10% to 20%. The “synergy factors” discussed in this section further adjust these multiplicatively combined
effectiveness values.

119 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), at 29-30. Available at http://tonto.eia.doe.gov/ftproot/modeldoc/m070(2007).pdf (last accessed Oct. 24, 2008).

120 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-56

simulation.

Many comments were received that stated this and pointed to erro rs in the synergies listed in the NPRM being in some cases inac curate or even directionally incorrect. NHTSA recognizes that the estimated synerg ies applied for the NPRM were not all correct, and has reevaluated al l estimated synergies applie d in the analysis supporting today’s final rule. In response to comme nters calling for NHTSA to use full vehicle simulation, either in the first instance or as a check on the synergy factors that NHTSA developed, the agency has concluded that the vehicle simulation analyses conducted previously by Ricardo provide a sufficient poin t of reference, especi ally considering the time constraints for establishing the fina l rule. NHTSA did, however, improve the predictive capability of the lumped parameter tool.

The lumped parameter tool was first updated wi th the new list of technologies and their associated effectiveness values. Second, NHTSA conducted a more rigorous qualitative analysis of the technologies for which a competition for losses would be expected, which led to a much larger list of synergy pairings than was present in the NRPM. The types of losses that were analyzed were tractive effort , transmission/drivetrain, engine mechanical friction, engine pumping, engine indicated (combustion) effi ciency and accessory (see Table V-5). As can be seen from Table V-5, engine mechanical friction, pumping and accessory losses are improved by various technologies from engine, transmission, electrification and hybrid decision trees and mu st be accounted for within the model with a synergy value. The updated lumped para meter model was then re-run to develop new synergy estimates for the expanded list of pairin gs. That list is shown in Tables IV-6a-d. The agency notes that synergies that occur within a decision tree are already addressed within the incremental values assigned and therefore do not require a synergy pair to address. For example, all engine technologi es take into account incremental synergy factors of preceding engine technologies, a nd all transmission technologies take into account incremental synergy f actors 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 (see Tables IV-6a-d) which lists technol ogy pairings and incremental synergy factors associated with those pair ings, most of which are between engine technologies and transmission/el ectrification/hybrid technologie s. When a technology is applied to a vehicle by the Volpe model, all instances of that technology in the incremental synergy table which match technolo gies already applied to the vehicle (either pre-existing or previously applied by the Vo lpe model) are summed and applied to the fuel consumption improvement factor of th e technology being applied. Synergies for the strong hybrid technology fuel consumption re ductions are included in the incremental value for the specific hybrid technology block since the model applie s technologies in the
order of the most effectiveness for least cost and also applies all av ailable electrification and transmission technologies before applying strong hybrid technologies.V-57

As another possible alternative to using s ynergy factors, NHTSA has also considered modifying the Volpe model to apply inputs—for each vehicle model—specifying the share of total fuel consumption attributable to each of several energy loss mechanisms. The agency has determined that this approac h, discussed in greater detail below, cannot be implemented at this time because the requisite information is not available.V-58

Table V-5. Loss Factors Considered in Synergy Analysis

VEHICLE TRANS ENGINE ENGINE ENGINE ENGINE Tractive Drivetrain Mechanical Pumping Accessory Indicated

Effort Losses Friction Losses Losses Efficiency

ENGINE

Low Friction Lubricants + Engine Friction Reduction + VVT - Coupled Cam Phasing (CCP) on SOHC - + + Discrete Variable Valve Lift (DVVL) on SOHC - + Cylinder Deactivation on SOHC + + VVT - Intake Cam Phasing (ICP) - + + VVT - Dual Cam Phasing (DCP) - + + Discrete Variable Valve Lift (DVVL) on DOHC - + Continuously Variable Valve Lift (CVVL) - + Cylinder Deactivation on DOHC + + Cylinder Deactivation on OHV + + VVT - Coupled Cam Phasing (CCP) on OHV -+ + Discrete Variable Valve Lift (DVVL) on OHV - +

Conversion to DOHC with DCP - + + Stoichiometric Gasoline Direct Injection (GDI) +

Combustion Restart + ++ Turbocharging and Downsizing - + Exhaust Gas Recirculation (EGR) Boost +

Conversion to Diesel + +

ELECTRIFICATION/ACCESSORY Electric Power Steering + Improved Accessories + 12V Micro-Hybri d + ++ Higher Voltage/Improved Alternator + Integrated Starter Generator + + +
TRANSMISSION (MANUAL) 6-Speed Manual/Improved Internals + + TRANSMISSION (AUTOMATIC) Improved Auto. Trans. Controls/Externals + + Continuously Variable Transmission - + 6/7/8-Speed Auto. Trans with Impr. Internals + +

Dual Clutch/Automated Manual Transmission + (STRONG) HYBRID Power Split Hybrid + + ++ 2-Mode Hybrid + + ++ Plug-in Hybrid + + ++

VEHICLE Material Substitution (1%) + Material Substitution (2%) + Material Substitution (5%) + Low Rolling Resistance Tires + Low Drag Brakes + Secondary Axle Disconnect - 4WD + Aero Drag Reduction + 

## Lumped Parameter Synergy Analysis

+ Technology has a positive effect on fuel consumption - Technology has a negative effect on fuel consumptionV-59

Table V-6a. Synergy pairings and values

Technology A Technology B Subcompact

PC Subcompact

Perf. PC Compact PC Compact

Perf. PC Midsize PC Midsize Perf.

PC

CCPS 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

CCPS IATC -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CCPS CVT -0.8% -0.8% -0.8% -0.8% -0.8% -0.8%

CCPS NAUTO -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

CCPS MHEV -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

CCPS ISG -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

DVVLS 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

DVVLS IATC -0.5% -0.5% -0.5% -0.5% -0.5% -0.5%

DVVLS CVT -1.4% -1.4% -1.4% -1.4% -1.4% -1.4%

DVVLS NAUTO -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DVVLS MHEV -0.8% -0.8% -0.8% -0.8% -0.8% -0.8%

DVVLS ISG -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

DEACS 6MAN n.a. n.a. n.a. -0.2% n.a. -0.2%

DEACS IATC n.a. n.a. n.a. -0.6% n.a. -0.6%

DEACS CVT n.a. n.a. n.a. -1.7% n.a. -1.7%

DEACS NAUTO n.a. n.a. n.a. -0.9% n.a. -0.9%

DEACS MHEV n.a. n.a. n.a. -0.9% n.a. -0.9%

DEACS ISG n.a. n.a. n.a. -1.1% n.a. -1.1%

ICP 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

ICP IATC -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

ICP CVT -0.8% -0.8% -0.8% -0.8% -0.8% -0.8%

ICP NAUTO -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

ICP MHEV -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

ICP ISG -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

DCP 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

DCP IATC -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

DCP CVT -1.3% -1.3% -1.3% -1.3% -1.3% -1.3%

DCP NAUTO -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DCP MHEV -0.8% -0.8% -0.8% -0.8% -0.8% -0.8%

DCP ISG -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

DVVLD 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

DVVLD IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

DVVLD CVT -1.8% -1.8% -1.8% -1.8% -1.8% -1.8%

DVVLD NAUTO -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

DVVLD MHEV -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

DVVLD ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DEACD 6MAN n.a. n.a. n.a. -0.2% n.a. -0.2%

DEACD IATC n.a. n.a. n.a. -0.6% n.a. -0.6%

DEACD CVT n.a. n.a. n.a. -1.8% n.a. -1.8%

DEACD NAUTO n.a. n.a. n.a. -1.0% n.a. -1.0%

DEACD MHEV n.a. n.a. n.a. -0.9% n.a. -0.9%

DEACD ISG n.a. n.a. n.a. -1.1% n.a. -1.1%

CVVL 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CVVL IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CVVL CVT -1.8% -1.8% -1.8% -1.8% -1.8% -1.8%

CVVL NAUTO -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

CVVL MHEV -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

CVVL ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1% Synergies Fuel Consumption Improvement Synergy values by Vehicle Subclass Positive values are positive synergies, negative values are dissynergies.V-60

Table V-6b. Synergy pairings and values

Technology A Technology B Subcompact

PC Subcompact

Perf. PC Compact PC Compact

Perf. PC Midsize PC Midsize Perf.

PC

DEACO 6MAN n.a. n.a. n.a. -0.1% n.a. -0.1%

DEACO IATC n.a. n.a. n.a. -0.5% n.a. -0.5%

DEACO CVT n.a. n.a. n.a. -1.4% n.a. -1.4%

DEACO NAUTO n.a. n.a. n.a. -0.8% n.a. -0.8%

DEACO MHEV n.a. n.a. n.a. -0.9% n.a. -0.9%

DEACO ISG n.a. n.a. n.a. -1.2% n.a. -1.2%

CCPO 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CCPO IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CCPO CVT -1.7% -1.7% -1.7% -1.7% -1.7% -1.7%

CCPO NAUTO -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

CCPO MHEV -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

CCPO ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DVVLO 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

DVVLO IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DVVLO CVT -2.0% -2.0% -2.0% -2.0% -2.0% -2.0%

DVVLO NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DVVLO MHEV -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

DVVLO ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CDOHC 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CDOHC IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

CDOHC CVT -2.0% -2.0% -2.0% -2.0% -2.0% -2.0%

CDOHC NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CDOHC MHEV -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

CDOHC ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CBRST 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CBRST IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CBRST CVT -1.8% -1.8% -1.8% -1.8% -1.8% -1.8%

CBRST NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CBRST MHEV -2.1% -2.1% -2.1% -2.1% -2.1% -2.1%

CBRST ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CBRST EPS -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CBRST IACC -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

CBRST HVIA -0.3% -0.3% -0.3% -0.3% -0.3% -0.3%

TRBDS 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

TRBDS IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

TRBDS CVT -2.4% -2.4% -2.4% -2.4% -2.4% -2.4%

TRBDS NAUTO -1.3% -1.3% -1.3% -1.3% -1.3% -1.3%

TRBDS MHEV -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

TRBDS ISG -1.3% -1.3% -1.3% -1.3% -1.3% -1.3%

DSLC 6MAN -0.3% -0.3% -0.3% -0.3% -0.3% -0.3%

DSLC IATC 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

DSLC CVT -2.9% -2.9% -2.9% -2.9% -2.9% -2.9%

DSLC NAUTO -1.7% -1.7% -1.7% -1.7% -1.7% -1.7%

DSLC MHEV -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DSLC ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DSLT 6MAN -0.3% -0.3% -0.3% -0.3% -0.3% -0.3%

DSLT IATC 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

DSLT CVT -2.9% -2.9% -2.9% -2.9% -2.9% -2.9%

DSLT NAUTO -1.7% -1.7% -1.7% -1.7% -1.7% -1.7%

DSLT MHEV -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DSLT ISG -1.1% -1.1% -1.1% -1.1% -1.1% -1.1% Synergies Fuel Consumption Improvement Synergy values by Vehicle Subclass Positive values are positive synergies, negative values are dissynergies.V-61

Table V-6c. Synergy pairings and values

Technology A Technology B Large PC Large Perf.

PC Minivan LT Small LT Midsize LT Large LT

CCPS 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

CCPS IATC -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CCPS CVT -0.8% n.a. -0.8% -0.8% -0.8% n.a.

CCPS NAUTO -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

CCPS MHEV -0.7% -0.7% -0.7% -0.7% -0.7% n.a.

CCPS ISG -0.9% -0.9% -0.9% -0.9% -0.9% n.a.

DVVLS 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

DVVLS IATC -0.5% -0.5% -0.5% -0.5% -0.5% -0.5%

DVVLS CVT -1.4% n.a. -1.4% -1.4% -1.4% n.a.

DVVLS NAUTO -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DVVLS MHEV -0.8% -0.8% -0.8% -0.8% -0.8% n.a.

DVVLS ISG -1.0% -1.0% -1.0% -1.0% -1.0% n.a.

DEACS 6MAN -0.2% -0.2% -0.2% n.a. -0.2% -0.2%

DEACS IATC -0.6% -0.6% -0.6% n.a. -0.6% -0.6%

DEACS CVT -1.7% n.a. -1.7% n.a. -1.7% n.a.

DEACS NAUTO -0.9% -0.9% -0.9% n.a. -0.9% -0.9%

DEACS MHEV -0.9% -0.9% -0.9% n.a. -0.9% n.a.

DEACS ISG -1.1% -1.1% -1.1% n.a. -1.1% n.a.

ICP 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

ICP IATC -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

ICP CVT -0.8% n.a. -0.8% -0.8% -0.8% n.a.

ICP NAUTO -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

ICP MHEV -0.7% -0.7% -0.7% -0.7% -0.7% n.a.

ICP ISG -0.9% -0.9% -0.9% -0.9% -0.9% n.a.

DCP 6MAN -0.1% -0.1% -0.1% -0.1% -0.1% -0.1%

DCP IATC -0.4% -0.4% -0.4% -0.4% -0.4% -0.4%

DCP CVT -1.3% n.a. -1.3% -1.3% -1.3% n.a.

DCP NAUTO -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DCP MHEV -0.8% -0.8% -0.8% -0.8% -0.8% n.a.

DCP ISG -1.0% -1.0% -1.0% -1.0% -1.0% n.a.

DVVLD 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

DVVLD IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

DVVLD CVT -1.8% n.a. -1.8% -1.8% -1.8% n.a.

DVVLD NAUTO -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

DVVLD MHEV -0.9% -0.9% -0.9% -0.9% -0.9% n.a.

DVVLD ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

DEACD 6MAN -0.2% -0.2% -0.2% n.a. -0.2% -0.2%

DEACD IATC -0.6% -0.6% -0.6% n.a. -0.6% -0.6%

DEACD CVT -1.8% n.a. -1.8% n.a. -1.8% n.a.

DEACD NAUTO -1.0% -1.0% -1.0% n.a. -1.0% -1.0%

DEACD MHEV -0.9% -0.9% -0.9% n.a. -0.9% n.a.

DEACD ISG -1.1% -1.1% -1.1% n.a. -1.1% n.a.

CVVL 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CVVL IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CVVL CVT -1.8% n.a. -1.8% -1.8% -1.8% n.a.

CVVL NAUTO -1.0% -1.0% -1.0% -1.0% -1.0% -1.0%

CVVL MHEV -0.9% -0.9% -0.9% -0.9% -0.9% n.a.

CVVL ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a. Synergies Fuel Consumption Improvement Synergy values by Vehicle Subclass Positive values are positive synergies, negative values are dissynergies.V-62

Table V-6d. Synergy pairings and values

Technology A Technology B Large PC Large Perf.

PC Minivan LT Small LT Midsize LT Large LT

DEACO 6MAN -0.1% -0.1% -0.1% n.a. -0.1% -0.1%

DEACO IATC -0.5% -0.5% -0.5% n.a. -0.5% -0.5%

DEACO CVT -1.4% n.a. -1.4% n.a. -1.4% n.a.

DEACO NAUTO -0.8% -0.8% -0.8% n.a. -0.8% -0.8%

DEACO MHEV -0.9% -0.9% -0.9% n.a. -0.9% n.a.

DEACO ISG -1.2% -1.2% -1.2% n.a. -1.2% n.a.

CCPO 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CCPO IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CCPO CVT -1.7% n.a. -1.7% -1.7% -1.7% n.a.

CCPO NAUTO -0.9% -0.9% -0.9% -0.9% -0.9% -0.9%

CCPO MHEV -1.0% -1.0% -1.0% -1.0% -1.0% n.a.

CCPO ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

DVVLO 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

DVVLO IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

DVVLO CVT -2.0% n.a. -2.0% -2.0% -2.0% n.a.

DVVLO NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

DVVLO MHEV -1.0% -1.0% -1.0% -1.0% -1.0% n.a.

DVVLO ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

CDOHC 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CDOHC IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

CDOHC CVT -2.0% n.a. -2.0% -2.0% -2.0% n.a.

CDOHC NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CDOHC MHEV -1.0% -1.0% -1.0% -1.0% -1.0% n.a.

CDOHC ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

CBRST 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

CBRST IATC -0.6% -0.6% -0.6% -0.6% -0.6% -0.6%

CBRST CVT -1.8% n.a. -1.8% -1.8% -1.8% n.a.

CBRST NAUTO -1.1% -1.1% -1.1% -1.1% -1.1% -1.1%

CBRST MHEV -2.1% -2.1% -2.1% -2.1% -2.1% n.a.

CBRST ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

CBRST EPS -0.2% -0.2% -0.2% -0.2% -0.2% n.a.

CBRST IACC -0.4% -0.4% -0.4% -0.4% n.a. n.a.

CBRST HVIA -0.3% -0.3% -0.3% -0.3% -0.3% n.a.

TRBDS 6MAN -0.2% -0.2% -0.2% -0.2% -0.2% -0.2%

TRBDS IATC -0.7% -0.7% -0.7% -0.7% -0.7% -0.7%

TRBDS CVT -2.4% n.a. -2.4% -2.4% -2.4% n.a.

TRBDS NAUTO -1.3% -1.3% -1.3% -1.3% -1.3% -1.3%

TRBDS MHEV -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

TRBDS ISG -1.3% -1.3% -1.3% -1.3% -1.3% n.a.

DSLC 6MAN -0.3% -0.3% -0.3% -0.3% -0.3% -0.3%

DSLC IATC 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

DSLC CVT -2.9% n.a. -2.9% -2.9% -2.9% n.a.

DSLC NAUTO -1.7% -1.7% -1.7% -1.7% -1.7% -1.7%

DSLC MHEV -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

DSLC ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

DSLT 6MAN -0.3% -0.3% -0.3% -0.3% -0.3% -0.3%

DSLT IATC 2.5% 2.5% 2.5% 2.5% 2.5% 2.5%

DSLT CVT -2.9% n.a. -2.9% -2.9% -2.9% n.a.

DSLT NAUTO -1.7% -1.7% -1.7% -1.7% -1.7% -1.7%

DSLT MHEV -1.1% -1.1% -1.1% -1.1% -1.1% n.a.

DSLT ISG -1.1% -1.1% -1.1% -1.1% -1.1% n.a. Synergies Fuel Consumption Improvement Synergy values by Vehicle Subclass Positive values are positive synergies, negative values are dissynergies.V-63

8. How does NHTSA use full vehicle simulation? For regulatory purposes, the fuel economy of any given vehicle is determined by placing the vehicle on a chassis dynamometer (akin to a large treadmill that puts the vehicle’s wheels in contact with one or more rollers, rather than with a belt stretched between rollers) in a controlled envir onment, driving the vehicle over a specific driving cycle (in which driving speed is specified for each second of operation), measuring the amount of
carbon dioxide emitted from the vehicle’s ta ilpipe, and calculating fuel consumption based on the density and carbon content of the fuel.

One means of determining the effectiveness of a given technology as applied to a given
vehicle model would be to measure th e vehicle’s fuel economy on a chassis dynamometer, install the new technology, and then re-measure the vehicle’s fuel economy. However, most technologies cannot simply be “swapped out,” and even for those that can, simply doing so without addi tional engineering work may change other vehicle characteristics ( e.g. , ride, handling, performance, et c.), producing an “apples to oranges” comparison.

Some technologies can also be more narro wly characterized thr ough bench or engine dynamometer ( i.e. , in which the engine drives a generato r that is, in turn, used to apply a controlled load to the engine) testing. For example, engine dynamometer testing could be used to evaluate the brake-specific fuel consumption ( e.g. , grams per kilowatt-hour) of a given engine before and after replacing the e ngine oil with a less viscous oil. However, such testing does not provide a direct measure of overall vehicle fuel economy or changes in overall vehicle fuel economy.

For a vehicle that does not yet exist, as in NHTSA’s analysis of CAFE standards applicable to future model years, even phys ical testing can provide only an estimate of the vehicle’s eventual fuel economy. Am ong the alternatives to physical testing, automotive engineers involved in vehicle desi gn make use of computer-based analysis tools, including a powerful cl ass of tools commonly refe rred to as “full vehicle simulation.” Given highly de tailed inputs regarding vehicle engineering characteristics, full vehicle simulation provides a means of estimating vehicle fuel consumption over a given drive cycle, based on the explicit re presentation of the physical laws governing vehicle propulsion and dynamics. Some ve hicle simulation tools also incorporate combustion simulation tools that represent the combustion cycle in terms of governing physical and chemical processes. Although th ese tools are computa tionally intensive and required a great deal of input data, they provide engineers involved in vehicle development and design with an alternative that can be considerably faster and less expensive than physical e xperimentation and testing.

Properly executed, methods such as physical testing and full vehicle simulation can provide reasonably (though not ab solutely) certain estimates of the vehicle fuel economy of specific vehicles to be produced in the future. However, when analyzing potential CAFE standards, NHTSA is not actually de signing specific vehicles. The agency is considering implications of new standards th at will apply to the average performance ofV-64

manufacturers’ entire production lines. For this type of analysis, precision in the estimation of the fuel economy of individual vehicle models is not essential; although it is important that the agency avoid systematic upward or downward bias, uncertainty at the level of individual models is mitigated by the fact that compliance with CAFE standards is based on average fleet performance.

As discussed above, the Volpe Model, which th e agency has used to perform the analysis supporting today’s final rule, applies an incrementally multiplicative approach to estimating the fuel savings achieved through the progressive addi tion of fuel-saving technologies. NAS’ use of the same appro ach in its 2002 report was, at the time and henceforth, criticized by a small number of observers as being prone to systematic overestimation of available fuel savings. This assertion was based on the fact that, among the technologies present on any given ve hicle, more than one may address the same energy loss mechanism (notably, pumping losses on throttled engines). Once all energy losses of a given type are eliminate d, even theoretical improvements attributable to that loss mechanism are no longer available.

The most direct critique of NAS’ methods appeared in a 2002 SAE paper by four General Motors researchers (Patton, et al. ), who compared some of NAS’ calculations to fuel consumption estimates obtained through vehi cle testing and simulation, and concluded that, as increasing numbers of technologi es were applied, NAS’ estimates became increasingly subject to overestimation of available fuel consumption reductions. 121

In response to such concerns, which had also been raised as the NAS committee performed its analysis, the NAS report concl uded that vehicle simulation performed for the committee indicated that the report’s incr emental fuel savings estimates were “quite reasonable” for the less aggressive two of the three product development paths it evaluated. The report did, however, concl ude that uncertainty increased with
consideration of more technol ogies, especially under the more aggressive “path 3” evaluated by the committee. The report did no t, however, mention any directional bias to this uncertainty. 122

Notwithstanding this prior response to con cerns about the possibl e overestimation of available fuel savings, and considering that analyses supporting the development of the NPRM, the Volpe model applies “synergy factor s” that adjust fuel savings calculations when some pairs of technologies are applied to the same ve hicle. These factors reduce uncertainty and the potential for positive or negative biases in the Volpe model’s estimates of the effects of technologies.

As an alternative to estimating fuel cons umption through incremental multiplication and the application of “synergy” factors to address technology interactions, NHTSA considered basing its analysis of fuel ec onomy standards on full vehicle simulation at

121 Patton, K.J., et al., General Motors Corporation, “Aggregating Technologies for Reduced Fuel Consumption: A Review of the Technical Content in the 2002 National Research Council Report on CAFE”, 2002-01-0628, Society of Automotive Engineers, Inc., 2002.

122 NRC (2002), op. cit. , p. 151.V-65

every step. However, considering the nature of CAFE analysis (in particular, the analysis of fleets projected to be sold in the future by each manufacturer), as well as the quantity and availability of information required to perform vehicle simulation, the agency explained that it believed detailed simulati on when analyzing the entire fleet of future vehicles is neither necessary nor feasible. Still, when estimating synergies between technologies, the agency did make use of vehi cle simulation studies, as discussed above. The agency has also done so when re-estima ting synergies before performing the analysis supporting today’s final rule.

NHTSA also considered estimating changes in fuel consumption by explicitly accounting for each of several energy loss mechanisms—t hat is, physical mechanisms to which the consumption of (chemical) energy in fuel ma y be attributed. This approach would be similar to that proposed in 2002 by Patton et al . The agency invited comment on this approach, requested that manufacturers submit product plans disaggregating fuel consumption into each of nine loss mechanis ms, and sought estimates of the extent to which fuel-saving technologies aff ect each of these loss mechanisms.

In response to the NPRM, the Alliance presen ted a detailed analysis by Sierra Research,
which used a modified version of VEHSIM (a vehicle simulation tool) to estimate the fuel consumption resulting from the applica tion of various vehicle technologies to 25 vehicle categories intended to represent th e fleet. The Alliance commented that this simulation-based approach is more accurate than that applied by NHTSA, and indicated that Sierra’s ability to perform this analysis demonstrates that NHT SA should be able to
do the same.

General Motors also raised questions regarding the multiplicative approach to fuel consumption estimation NHTSA has implemented using the Volpe model. GM indicated that the Volpe model should be enhanced w ith modifications to “take into account the basic physics of vehicles.” 123 Although GM’s comments did not explicitly mention vehicle simulation, GM did express fu ll support for the Alliance’s comments.

The California Air Resources Board (CARB) presented comparisons of different simulation studies, commenting that these de monstrate that the VEHSIM model used by Sierra Research “cannot accurately simulate ve hicles that use advanced technologies such as variable valve timing and lift and advanced transmissions.” 124 CARB also questioned Sierra Research’s simulation capabilities and suggested that, in s upport of actual product development, manufacturers neither contract with Sierra Res earch for such services nor
make use of VEHSIM. CARB further comm ented that both AVL (which performed
simulation studies for CARB’s evaluation of potential greenhouse gas standards) and

123 GM comments at 2, Docket No. NHTSA-2008-0089-0162.

124 CARB comments at 5, Docket No. NHTSA-2008-0089-0173. In developing potential greenhouse gas (GHG) emissions standards for light vehicles, CARB made significant use of vehicle simulation results presented in “Reducing Greenhouse Gas Emissions from Light-Duty Motor Vehicles” , which was published in 2004 by the Northeast States Center for a Clean Air Future (NESCCAF). As NHTSA discussed in the NPRM, CARB’s and NESCCAF’ s approach, which effectively reduces each manufacturer’s fleet to five “repre sentative” vehicles and two average vehicle weights, is too limited for purposes of CAFE analysis.V-66

Ricardo (which has recently performed simula tion studies and relate d analysis for both EPA and NHTSA) provide such services to manufacturers. 125

However, the Alliance and GM have criticized technical aspects of the AVL and Ricardo vehicle simulation studies mentioned by CARB . Regarding the AVL vehicle simulations CARB utilized, GM raised concerns th at, among other things, some of AVL’s simulations assumed the use of premium-grad e gasoline, and some effectively assume vehicle performance and utility would be compromised. 126 Similarly, the Alliance raised concerns that some of the simulations pe rformed by Ricardo for EPA assumed the use of premium fuel, and that many of the simulati ons assumed vehicle performance would be
reduced. 127 The Alliance also indicated that the five vehicles analyzed by Ricardo for EPA were not representative of all vehicles in the fleet, leading to overstatement of the degree of improvement potentially available to vehicles that alrea dy use technologies not present in the vehicles examined by EPA. Th e Alliance further argued that the report did not reveal sufficient detail regarding important simulation details (related, e.g. , to cylinder deactivation), that itfailed to account for some pa rasitic and accessory loads,
and that EPA directed Ricardo to unrealisti cally assume universal improvements in aerodynamics, tire efficiency, and powertrain friction. 128

Although submitted after the close of the comment period specified in the NPRM, comments by several state Attorneys General and other state and local official questioned
the need and merits of full vehicle simula tion within the context of CAFE analysis, stating that Computer simulation models such as VEHSIM are not practical except perhaps during vehicle development to determine the performance of specific vehicle models where all ve hicle engineering parameters are known and can be accounted for in the inputs to the model. Such an exercise is extremely data intensive, and extending it to the entire fleet makes it subject to multiple errors un less the specific parameters for each vehicle model are known and accounted for in the model inputs. 129

125 California Air Resources Board, “Air Resources Board Staff Comments on Sierra and Martec NRC

Presentations” , p. 2.

126 Testimony of Kenneth Patton (GM); Testimony of Kevin McMahon (Martec); Plaintiffs' Proposed Findings of Fact, June 15, 2007, pp. 103 -113.

127 Alliance of Automobile Manufacturers, “Detailed Technical Comments on Ricardo ‘Study of Potential Effectiveness of Carbon Dioxide Redu cing Vehicle Technologies’ Report” , March 6, 2008.

128 For the reader’s reference, Ricardo’s study for EPA was based on specific EPA-defined requirements, such as performing full vehicle simulations of 26 different technology packages on the EPA-specified 5 baseline vehicles. Thus, to the extent that Ricardo ’s numbers do not reflect specific differences in technology effectiveness by vehicl e model, in conducting the analysis for NHTSA’s final rule, NHTSA and Ricardo drew on Ricardo’s knowledge to develop incremental benefits based in part on Ricardo’s simulation work. Ricardo also noted differences between its report for EPA and the EPA Staff Technical Report in terms of the incremental benefits for individual technologies developed by EPA based on
Ricardo’s simulation.

129 Attorneys General of the States of California, Ar izona, Connecticut, Illinois, Maryland, Massachusetts, New Jersey, New Mexico, Oregon, and Vermont, the Ex ecutive Officer of the California Air Resources Board, the Commissioner of the New Jersey Department of Environmental Protecti on, the Secretary of the New Mexico Environment Department, the Secretary of the Commonwealth of Pennsylvania Department of Environmental Protection, and the Corporation Counsel of the City of New York, SupplementalV-67

Considering the comments summarized above, the analyses to which they refer, and the nature of the analysis the agency performs when evaluating potential CAFE standards,
NHTSA has concluded that full vehicle simu lation, though useful to manufacturers’ own product development efforts, remains neither necessary nor feasible for the MY 2011 CAFE analysis. NHTSA’s basis for this conclusion is as follows:

Full vehicle simulation involves estimati ng the fuel consumption (and, typically, emissions) of a specific vehicle over a sp ecific driving cycle. Many engineering characteristics of the vehicle must be sp ecified, including, but not limited to weight, rolling resistance, tire radi us, aerodynamic drag coefficien t, frontal area, engine maps 130 and detailed transmission characteristics (gear ratios, shift logic, etc.), other drivetrain characteristics, and accessory loads. Additi onal engine test data would also be required in order to update engine maps when eval uating the application of advanced engine technologies. Driving cycles—vehicle sp eeds over time—are specified on a second-bysecond (or more finely-grained) basis. Usi ng full vehicle simulation to estimate average fuel consumption under the test procedures relevant to CAFE involves many simulations to capture all the potential combinations of technologies th at could be used.

Given all of the requisite data representing a specific vehicl e, full vehicle simulation can provide a powerful means of estimating vehicle performance while accounting for interactions between various vehicle compone nts and systems. Full simulation can also provide a means of estimating vehicle performance under driving conditions not represented by the fuel economy test procedures . For an engineer involved in the design of a specific vehicle or vehicle component or system, or a manufacturer making specific decisions regarding the fleet of vehicles it will produce, vehicle simulation can be a powerful tool. However, even the most detailed simulation involving full combustion cycle simulation is not the “gold standard” fo r product design. Chrysler, for example, has portrayed simulation as one of several tools in its CAFE planning process, which also involves physical testing ( i.e. , bench testing, chassis dynamo meter testing) of actual components and assembled vehicles. 131

In purpose and corresponding requirements, NHTS A’s evaluation of regulatory options is fundamentally different from the type of product planning and development that a
manufacturer conducts. A manuf acturer must make specific decisions regarding every component that will be installed in ever y vehicle it plans to produce, and it must ultimately decide how many of each vehicl e it will produce. Although manufacturers have some ability to make “mid-course adjustments,” that ability is limited by a range of factors, such as contracts and tooling investments. By comparison, NHTSA attempts

Comments Regarding Alliance of Au tomobile Manufacturers Comments , Docket No. NHTSA-2008-0089- 0495, October 8, 2008, p. 3.

130 An engine map specifies the engine’s efficiency under many different operating conditions, each of which is defined in terms of rotational speed ( i.e ., revolutions per minute, or RPM) and load ( i.e. , torque).

131 Fodale, F., Chrysler LLC, “Fuel Economy/Fuels—Presented to NRC Committee on Fuel Economy of Light-Duty Vehicles”, November 27, 2007.V-68

only to estimate how a given manufacturer might attempt to comply with a potential CAFE standard; given the range of options available to each manufacturer, NHTSA has little hope of predicting specifica lly what a given manufacturer will do. CAFE standards require average levels of performance, not specific technology outcomes. Therefore, while it is important that NHT SA avoid systematic bias when estimating the potential to increase the fuel economy of specific vehicle mo dels, it is not important that the agency’s estimates precisely forecast results for every future vehicle.

Furthermore, NHTSA evaluates the impact of CAFE standards on all manufacturers, based on a forecast of specific vehicle models each manufacturer will produce for sale in the U.S. in the future. An analysis for MY 2011 can involve thousa nds of unique vehicle models, hundreds of unique engines, and hundred s of unique transmissions. Model-bymodel representation, as used in the analysis for this final rule, allows the agency to, among other things, account for technologies expected to be present on each vehicle under “business as usual” conditions, thereby avoiding errors regarding the potential to add further technologies.

Because of the intense informational and computational requirements, industry-wide studies that rely on vehicle simulation re duce the fleet to a limited number of “representative” vehicles. This reduction lim its the ability to a ccount for technological and other heterogeneity of the fleet, vi rtually ensuring the overestimation of improvements available to some vehicles ( e.g. , vehicles that begin with a great deal of technology) and some manufacturers ( e.g. , manufacturers that sell many high-technology vehicles). AVL’s analysis for NESCCAF a nd Ricardo’s analysis for EPA, each of which considered only five vehicle models, are bot h, therefore, of severely limited use for the kind of fleetwide analysis used in this fina l rule, although both provi de useful information regarding the range of fuel savings achieved by specific technologies and “packages” of technologies.

The analysis conducted by Sierra Research for the Alliance considers a significantly greater number (25) of “repre sentative” vehicles, drawing im portant distinctions between similarly-sized cars based on performance. Sie rra was able to do so in part because it analyzed historical vehicles. For example, Sierra indicates that model year 1998 engines were used to supply VEHSIM with baseline, “blended” engine maps applied universally (rather than specific maps for each manufactur er and vehicle model) for vehicle model years out to 2020. Considering that, even w ithout increases in CAFE standards, many vehicles produced for sale in the U.S. dur ing the time period considered in a CAFE rulemaking are likely to have technologi es such as VVLT and cylinder deactivation, NHTSA doubts “blended” 1998 engines are as representative as implied by Sierra’s analysis.

Although NHTSA could, in principle, integrat e full vehicle simulation of every vehicle model into its analysis of the future fleet, th e agency expects that manufacturers would be unable to provide much of the required info rmation for future vehicles. Even if manufacturers were to provide such information, using full ve hicle simulation to estimate the effect of further technological improve ments to future vehicles would involveV-69

uncertain detailed estimates, such as va lve timing, cylinder deactivation operating conditions, transmission shift points, and hybrid vehicle energy management strategies for each specific vehicle, engine, and transm ission combination. Even setting aside the vast increases in computational demands that would accompany the use of full vehicle simulation in model-by-model analysis of the entire fleet, the agency remains convinced that the availability of underlying informa tion and data would be too limited for this approach to be practical.

As a third alternative, one that might be mo re explicitly “physics-ba sed” than the use of synergy factors and vastly more practical th an full vehicle simulation, NHTSA requested comment on the use of partitioned fuel consumption accounting. Aside from GM’s nonspecific recommendation that the Volpe mode l be modified to account for the “basic physics of vehicles,” NHTSA did not receive comments regarding the relative merits of partitioning fuel consumption into several energy loss mechanisms for purposes of estimating the effects of fuel-saving technolog ies, even though the concept is similar to that proposed by Patton, et al. in 2002. 132 Some manufacturers provided some of the information that would have been necessary for the implementation of this approach. However, as a group, manufacturers that submitted product plan information to the agency provided far too little disaggregated fuel consumption information to support the development of this approach. Although NHT SA continues to believe that partitioning fuel consumption into various loss mechanisms could provide a practical and sound basis for future analysis, the inform ation required to support this ap proach is not available at
this time.

In conclusion, NHTSA observes that with resp ect to the CAFE analysis prepared for this final rule, full vehicle simulation could theoreti cally be used at thr ee different levels. First, full vehicle simulation could be used only to provide specific estimates, that, combined with other data (e.g., from bench te sting) would provide a basis for estimates of the effectiveness of specific individua l technologies. While NHTSA will continue considering this type of analysis, the agency an ticipates that it will continue to be feasible and informative to make somewhat greater use of full vehicle simulation. Second, full vehicle simulation could be fully integrated into NHTSA’s model-by-model analysis of the entire fleet to be projected to be produ ced in future model years. NHTSA expects, however, that this level of integration will remain infeasible considering the size and complexity of the fleet. Also, consideri ng the forward-looking nature of NHTSA’s analysis, and the amount of information re quired to perform full vehicle simulation, NHTSA anticipates that this level of inte gration would involve misleadingly precise estimates of fuel consumption, even for MY 2011. Finally, full vehicle simulation can be used to develop less complex representations of interactions betw een technologies (such as was done using the lumped parameter mode l to develop the synergies for the final rule), and to perform reference points to which vehicle-specific estimates may be compared. NHTSA views this as a practical and productive potential use of full vehicle

132 Patton, et al. , present an energy balance calculation that di saggregates fuel consumption into six energy loss categories, indicating that “an accounting of the effects of individual technologies on energy losses within these categories provides a practical, physica lly-based means to evalua te and compare the fuel consumption effects of the various technologies.” (Patton, et. al. , (2002), op. cit. , p. 11.)V-70

simulation, and will consider following this approach in the future. NHTSA has contracted with NAS to, among other things, evaluate the potential use of full vehicle simulation and other fuel consumption estim ation methodologies. Nevertheless, in addition to considering further modifications to the Volpe model, NHTSA will continue to consider other methods for evaluating th e cost and effect of adding technology to
manufacturers’ fleets.

9. Refresh and redesign schedule In addition to, and as discussed below, de veloping analytical methods that address
limitations on overall rates at which new t echnologies can be expected to feasibly penetrate manufacturers’ fleets, the agency has also developed methods to address the feasible scheduling of changes to specific vehi cle models. In the Volpe model, which the agency has used to support the current rulemaking, these scheduling-related methods were first applied in 2003, in response to concerns that an early version of the model would sometimes add and then subsequently remove some technologies. 133 By 2006, these methods were integrated into a new ve rsion of the model, one which explicitly “carried forward” technologies added to one vehicle model to succeeding vehicle models in the next model year, and which timed the a pplication of many techno logies to coincide with the redesign or freshening of any given vehicle model. 134

Even within the context of the phase-in caps discussed be low, NHTSA considers these model-by-model scheduling constraints necessary in order to produce an analysis that reasonably accounts for the need for a period of stability following the redesign of any given vehicle model. If engineering, tooli ng, testing, and other rede sign-related resources were free, every vehicle model could be re designed every year. In reality, however, every vehicle redesign consumes resources si mply to address the redesign. Phase-in caps, which are applied at the level of manuf acturer’s entire fleet , do not constrain the scheduling of changes to any particular vehicle model. Conversely, scheduling constraints to address vehicle freshening a nd redesign do not necessarily yield realistic overall penetration rates ( e.g. , for strong hybrids).

In the automobile industry ther e are two terms that describe when changes to vehicles occur: redesign and refresh ( i.e. , freshening). Vehicle rede sign usually encompasses changes to a vehicle’s appearance, shape, di mensions, and powertrain, and is traditionally
associated with the introduction of “new” vehicles into the market, which is often characterized as the next gene ration of a vehicle. In cont rast, vehicle refresh usually encompasses only changes to a vehicle’s appearance, and may include an upgraded powertrain. Refresh is tradit ionally associated with mid-cycle cosmetic changes to a vehicle, within its current generation, to make it appear “fresh.” Vehicle refresh traditionally occurs no earlier than two years af ter a vehicle redesign or at least two years before a scheduled redesign. In the NPRM, NHTSA tied the application of the majority of the technologies to a vehi cle’s refresh/redesign cycle, because their application was significant enough that it could involve substantial engineer ing, testing, and calibration
work.

133 68 FR 16874 (Apr. 7, 2003).

134 71 FR 17582 (Apr. 6, 2006).V-71

NHTSA based the redesign and refresh schedul es used in the NPRM as inputs to the Volpe model on a combination of manufact urers’ confidentia l product plans and NHTSA’s engineering judgment . In most instances, NHTSA reviewed manufacturers’ planned redesign and refresh schedules and used them in the same manner it did in past rulemakings. However, in NHTSA’s judgmen t, manufacturers’ planned redesign and
refresh schedules for some vehicle models we re unrealistically slow considering overall market trends. In these cases, the agency re-estimated redesign and refresh schedules more consistent with the agency’s expectati ons, as discussed below. Also, if companies did not provide product plan data, NHTSA us ed publicly available data about vehicle redesigns to project the redesi gn and refresh schedules for the vehicles produced by these companies. 135

Unless a manufacturer submitted plans for a more rapid redesign and refresh schedule, NHTSA assumed that passenger cars would norma lly be redesigned every 5 years, based on the trend over the last 10-15 years s howing that passenger cars are typically redesigned every 5 years. These trends were reflected in the manu facturer product plans that NHTSA used in the NPRM analysis, a nd were also confirmed by many automakers in meetings held with NHTSA to discu ss various general issues regarding the rulemaking.

NHTSA explained that it believes that th e vehicle design process has progressed and improved rapidly over the last decade and that these improvements have made it possible for some manufacturers to shorten the design process for some vehicles in order to introduce vehicles more frequently in res ponse to competitive market forces. Although manufacturers have likely already taken a dvantage of most available improvements, according to public and confidential data ava ilable to NHTSA, almost all passenger cars will be on a 5-year redesign cycle by the e nd of the decade, with the exception being some high performance vehicles and vehicles with specific market niches.

NHTSA also stated in the NPRM that light trucks are currently redesigned every 5 to 7 years, with some vehicles (like full-size va ns) having longer redesign periods. In the most competitive SUV and crossover vehicl e segments, the redesign cycle currently averages slightly above 5 years. NHTSA explai ned that it is expected that the light truck redesign schedule will be shorte ned in the future due to competitive market forces Thus, for almost all light trucks scheduled for a redesign in model year 2014 and later, NHTSA projected a 5-year redesign cycle. Exceptions were made for high performance vehicles and other vehicles that traditionally had l onger than average design cycles. For those vehicles, NHTSA attempted to preserve their historical redesign cycle rates.

NHTSA discussed these assumptions with se veral manufacturers at the NPRM stage,
before the current economic cris is. Two manufacturers indicate d at that time that their vehicle redesign cycles take at least five years for cars and 6 years and longer for trucks because they rely on those late r years to earn a profit on the vehicles. They argued that

135 Sources included, but were not limited to manufacturers’ web sites, industry trade publications ( e.g. , Automotive News), and commercial data sources ( e.g. , Wards Automotive, etc.).V-72

they would not be able to sustain their busin ess if forced by CAFE standards to a shorter redesign cycle. The agency recognizes that some manufacturers are severely stressed in the current economic environment, and that some manufacturers may be hoping to delay planned vehicle redesigns in or der to conserve financial reso urces. However, consistent
with its forecast of the overall size of th e light vehicle market from MY 2011 on, the agency currently expects that the industry’s status will improve, and that manufacturers will typically redesign both car and truck models every 5 years in order to compete in that
market.

NHTSA received relatively few comments regarding its refresh/redesign schedule assumptions. UCS commented that redesign sc hedules should be shortened to 3 years, based on recent public statements by Ford that they intended to move to that cycle, and
based on other recent manufacturer behavior.

Although NHTSA agrees with UCS that remark s by one Ford official at a January 2008 conference suggest that that company was th en hoping to accelera te its vehicle “cycle time” to 3 years, the agency questions the context, intended meaning and scope, and representation of those remarks. 136 Further, the agency notes that the article referenced by UCS also indicates that “m ost manufacturers make changes to their vehicle lines every four years or more, depending on the segment of the market, with mid-cycle freshenings every two years or so.” 137 Although some manufacturers ha ve, in their product plans, indicated that they plan to redesign some vehicle models mo re frequently than has been the industry norm, all manufactur ers have also indicated that they expect to redesign some other vehicle models considerably less frequently. The CAR report submitted by the Alliance, prepared by the Center for Auto motive Research and EDF, states that “For a given vehicle line, the time from conception to first production ma y span two and onehalf to five years,” but that “The time from first production (“Job #1”) to the last vehicle off the line (“Balance Out”) may span from four to five years to eight to ten years or more, depending on the dynamics of the market segment.” The CAR report then states that “At the point of final production of the current vehicl e line, a new model with the same badge and similar characteristics may be ready to take its place, continuing the cycle, or the old model may be drop ped in favor of a different product.” 138

NHTSA believes that this description, wh ich states that a vehicle model will be redesigned or dropped after 4-10 years, is cons istent with other characterizations of the redesign and freshening process, and supports its 5-year re design assumption and its 2-3 year refresh cycle assumptions. 139 Thus, for purposes of the final rule, NHTSA is retaining the 5-year redesi gn/2-3 year refresh assumpti ons employed in the NPRM. However, NHTSA will continue to monitor manufacturing trends and will reconsider these assumptions in subseque nt rulemakings if warranted.

136 Zoia, D.E. 2008. Ford to cut cycle times to thre e years. Online at http://www.wardsauto.com. January

24.

137 Id

. 138 See NHTSA-2008-0089-0170.1, Attachment 16, at 8 (393 of pdf).

139 See id. , at 9 (394 of pdf).V-73

For purposes of the final rule, NHTSA has also considered conf idential product plans where applicable and industry trends on refres h and redesign timing as discussed above, to apply specific technologies at redesign, refr esh, or any model years as shown in Table
V-7 below.V-74

Table V-7. Technology Refresh and Redesign Application

Technology Redesign only Redesign or Refresh Anytime

Low Friction Lubricants X Engine Friction Reduction X VVT - Coupled Cam Phasing (CCP) on SOHC X Discrete Variable Valve Lift (DVVL) on SOHC X Cylinder Deactivation on SOHC X VVT - Intake Cam Phasing (ICP) X VVT – Dual Cam Phasing (DCP) X Discrete Variable Valve Lift (DVVL) on DOHC X Continuously Variable Valve Lift (CVVL) X Cylinder Deactivation on DOHC X Cylinder Deactivation on OHV X VVT - Coupled Cam Phasing (CCP) on OHV X Discrete Variable Valve Lift (DVVL) on OHV X

Conversion to DOHC with DCP X Stoichiometric Gasoline Direct Injection (GDI) X

Combustion Restart X Turbocharging and Downsizing X Exhaust Gas Recirculation (EGR) Boost X Conversion to Diesel following CBRST X Conversion to Diesel following TRBDS X Electric Power Steering X Improved Accessories X 12V Micro-Hybrid X Higher Voltage/Improved Alternator X Integrated Starter Generator X 6-Speed Manual/Improved Internals X Improved Auto. Trans. Controls/Externals X Continuously Variable Transmission X 6/7/8-Speed Auto. Trans with Improved Internals X

Dual Clutch or Automated Manual Transmission X Power Split Hybrid X 2-Mode Hybrid X Plug-in Hybrid X Material Substitution (1%) X Material Substitution (2%) X Material Substitution (5%) X Low Rolling Resistance Tires X Low Drag Brakes X Secondary Axle Disconnect X Aero Drag Reduction XV-75

As the table shows, most technologies are applied by the Volpe model when a specific vehicle is due for a redesign or refresh. Howe ver, for low friction lubricants, the model is not restricted to applying it during a refresh/redesign year an d thus it was made available for application at any time. Low friction lubricants are very cost-effective, can apply to multiple vehicle models/platforms and can be applied across multiple vehicle models/platforms in one year. Altho ugh they can also be applied during a refresh/redesign year, they are no t restricted to that timefram e because their application is not viewed as necessitating a major engineering redesign and associated testing/calibration.

For several technologies estimated in the NP RM to be available for application during any model year, NHTSA now estimates that th ese technologies will be available only at refresh or redesign. Those technologies include aggre ssive shift logic, improved accessories, low rolling resistance tires and low drag brakes. Aggressive shift logic is now one of the technologies included under improved automa tic transmission controls. This technology requires a recalibration specific to each vehicle, such that it can therefore be applied only at refresh or redesign model years. The “improved accessories” technology has been redefined to include in telligent engine cooling systems, which require a considerable change to the vehi cle and engine cooling system; therefore, improved accessories also can be applied only at refresh or redesign model years. Also,
NHTSA concurs with manufacturers’ confidenti al statements that indicating that low drag brakes and low rolling resistance tires can be applied only at refresh or redesign model years due to the need for vehicle testing and calibration ( e.g. , to ensure safe handling and braking) when th ese technologies are applied.

10. Phase-in caps In 2002, NHTSA proposed the first increases in CAFE standards in six years due to a previous statutorily-imposed prohibition on setting new standards. That proposal, for MY 2005-2007 light truck standards, relied, in part, on a prec ursor to the current Volpe
model. This earlier model used a “technol ogy application algorithm” to estimate the technologies that manufacturers could appl y in order to comply with new CAFE
standards.

NHTSA received more than 65,000 comments on that proposal. Among those were many manufacturer comments concerning l ead time and the potential for rapid widespread use of new technologies. The ag ency noted that DaimlerChrysler and Ford “argued that the agency had underestimated th e lead time necessary to incorporate fuel economy improvements in vehicles, as well as the difficulties of introducing new technologies across a high volume fleet.” Specific to Volpe’s technology application algorithm, the agency noted that General Motors took issue with the algorithm’s “application of technologies to all truck lines in a single model year.” 140

In response to those concerns, Volpe’s algorith m was modified “to re cognize that capital costs require employment of technologies fo r several years, rather than in a single

140 68 FR 16874 (Apr. 7, 2003).V-76

year.” 141 Those changes moderated the rates at which technologies were estimated to penetrate manufacturers’ fleets in res ponse to the new (MY 2005-MY 2007) CAFE standards. These changes produced more realistic estimates of the technologies manufacturers could apply in response to th e new standards, and thereby produced more
realistic estimates of the costs of those standards.

Prior to the next rulemaking, the Volpe model underwent significant integration and improvement, including the accommodation of ex plicit “phase-in caps” to constrain the rates at which each technology would be esti mated to penetrate each manufacturer’s fleet in response to new CAFE standards. 142 As documented in 2006, the agency’s final standards for light trucks sold in MY 2008-MY 2011 were based on phase-in caps ranging from 17 percent to 25 percent (corresp onding to full penetration of the fleet within 4 to 6 years) for most technologi es, and from 3 percent to 10 percent (full penetration within 10 to 33 years) for more a dvanced technologies su ch as hybrid electric
vehicles. 143 The agency based these rates on cons ideration of comments and on the 2002 NAS Committee’s findings that “widespread pe netration of even existing technologies will probably require 4 to 8 years” and th at for emerging technologies “that require additional research and development, this time lag can be considerably longer”. 144

In its 2008 NPRM proposing new CAFE standa rds for passenger cars and light trucks sold during MY 2011-MY 2015, NHTSA consid ered manufacturers’ planned product offerings and estimates of technology availabi lity, cost, and effectiveness, as well as broader market conditions and technology de velopments. The agency concluded that many technologies could be deployed more rapi dly than it had estimated during the prior rulemaking. 145 For most engine technologies, the agency increased these caps from 17 percent to 20 percent, equivalent to re ducing the estimated time for potential fleet penetration from 6 years to 5 years. For st oichiometric gasoline direct injection (GDI) engines, the agency increased the phase-in cap from 3 percent to 20 pe rcent, equivalent to estimating that such engines could potentially penetrate a given manuf acturer’s fleet in 5 years rather than the previously-estimated 33 years. However, as in its earlier CAFE rulemakings, the agency continued to recogni ze that myriad constraints prohibit most technologies from being applied across an entire fleet of vehicles w ithin a year, even if those technologies are available in the market.

In addition to requesting further explan ation of NHTSA’s use of phase-in caps, commenters addressing phase-in cap s generally asserted one of three themes: (1) that hybrid phase-in caps were much lower th an market trends or manufacturer

141 Id ., at 16885.

142 These caps constrain the extent to which additional technology is applied by the model, beyond the levels projected in each manufacturer’s baseline fleet . Also, because manufacturers’ fleets are comprised of vehicles, engines, and transmissions sold in discrete volumes, phase-in caps cannot be applied as precise limits. In some cases (when a phase-in cap is small or a manufacturer has a limited product line), doing so would prevent the technology from being applied at a ll. Therefore, the Volpe model enforces each phasein cap constraint as soon as it has been exceeded by application of technologies to manufacturers.

143 71 FR 17572, 17679 (Apr. 6, 2006).

144 Id . at. 17572. See also 2002 NAS Report, at 5.

145 73 FR 24387-88 (May 2, 2008).V-77

announcements would otherwise suggest; (2) that the phase-in caps proposed in the NPRM were too high in the early years of the rulemaking and did not reflect the very small (from a manufacturing perspective) amount of lead-time between the final rule and the MY 2011 standards, and/or were too low in the later ye ars of the rulemaking given the relatively-increased amount of lead-time for those mode l years; (3) that there are insufficient resources (either in terms of capital or engineering) to implement the number of technologies implied by the phase-in caps simultaneously.

Agency response: NHTSA continues to recognize th at many factors constrain the rates
at which manufacturers will be ab le to feasibly add fuel-sav ing technologies to the fleets they will sell in the United States. For a given technology, examples of these factors may include, but would not be limited to the following:

• Is the technology ready for commercial us e? For example, can it operate safely and reliably under real-world driving conditions for several years and many
miles?

• If the technology requires special infrastructure ( e.g. , new electrical generation and charging facilities), how quick ly will that be put in place?

• How quickly can suppliers ramp up to pr oduce the technology in mass quantities? For example, how quickly can they obtain the materials, tooling, and engineering resources they will need?

• Are original equipment manufacturers (O EMs) ready to inte grate the technology into vehicles? For example, how quickly can they obtain the necessary tooling ( e.g. , retool factories), engineer ing, and financial resources?

• How long will it take to establish failure and warranty data, and to make sure dealers and maintenance and repair busi nesses have any new training and tooling required in order to work with the new technology?

• Will OEMs be able to reasonably recoup pr ior investments for tooling and other capital?

• To what extent are suppliers and OEMs constrained by preexisting contracts?

NHTSA cannot explicitly and quantitatively eval uate every one of these and other factors with respect to each manufacturer’s potentia l deployment of each technology available during the production intent or emerging t echnology framework. Attempting to do so would require an extraordinary effort by th e agency, and would lik ely be subject to tremendous uncertainties. For example, in the current economic and market environment, the agency expects that it woul d be impossible to reliably predict specific characteristics of future supply chains. Ther efore, the agency has concluded that it is appropriate to continue using phase-in caps to apply the agency’s best judgment of the
extent to which such factors combine to c onstrain the rates at wh ich technologies may feasibly be deployed. We note, however, th at many of the assumptions about phase-in caps made in this final rule apply to years beyond MY 2011, because as the NAS
Committee and commenters indica ted, technologies are phased in over several years, soV-78

the agency evaluated the phasing-in of tec hnologies over the five-y ear period proposed in the NPRM. NHTSA provides these assumpti ons both in response to comments and to provide context for the agency’s decisi ons regarding MY 2011 phase-in caps. We emphasize that all assumptions for years ot her than MY 2011 will be reconsidered for future rulemakings and may be s ubject to change at that time.

Considering the above-mentioned comments, NHTSA has concluded that the phase-in caps it applied during its analysis document ed in the 2008 NPRM resulted in technology penetration rates that were unrealistically high in the earlier model years covered by its proposal, particularly for MY 2011. This was a significant basis for the proposed standards’ “front loading” about which manuf acturers expressed serious concerns. In response, and based on this conclusion, the Volpe model was modified for purposes of the final rule analysis to use phase-in caps fo r each technology that vary from one year to the next, and that in many cases would have in creased more rapidly in the later years of the agency’s analysis than in earlier years. In making these changes, particularly to the MY 2011 phase-in caps, the agency has b een mindful of the need to provide
manufacturers sufficient lead ti me to add technologies to their fleets. In the agency’s judgment, its revised approach more realisti cally represents manuf acturers’ capabilities and therefore produces more realistic estima tes of the costs of new CAFE standards.

For some technologies, NHTSA also conclude d that slower overa ll rates of fleet penetration are more likely than the rates show n in the NPRM. The agency estimates that cylinder deactivation, stoichiometric GDI, a nd turbocharging with downsizing would be able to potentially be added to 12-14 percent of the fleet per year on average, rather than the 20 percent phase-in caps used in the NP RM for these technologies. Considering manufacturers’ comments and some aspects of its reevaluation of the incremental benefits of available engine technologie s, the agency has concluded that these technologies will, for some engines, require more significant hardware changes and certification burden than previous ly recognized, such that feasib le deployment is likely to
be somewhat slower than estimated in the NPRM.

NHTSA has also concluded, considering the co mplexities involved in deploying strongly hybridized vehicles ( i.e. , power split, two mode, and plug-in hybrids), it is unrealistic to expect that, in response to new CAFE standa rds, manufacturers can pr oduce more of such vehicles in MY 2011 than they are already planning. Therefore, NHTSA has set the MY 2011 phase-in cap for strong hybrids to zero in that model year. Based on new information regarding engineering resources entailed in developing new power split and two-mode hybrid vehicles, the agency estima ted in its analysis th at these technologies could be added to up to 11 percent and 8 per cent, respectively, of a given manufacturer’s long run fleet, rather than the 15 percent the agency estimated for the NPRM. The agency also considered a less aggressive 1 percent longer run pha se-in cap for plug-in hybrids, in part because although the agency expects that plug-in hybrids will rely on lithium-ion batteries, it is not clear whether a nd, if so, how the supply chain for large and robust lithium-ion batteries will develop.V-79

On the other hand, NHTSA has al so concluded that some tec hnologies can potentially be deployed more widely than estimated in the NPRM. For example, the agency estimates that 6/7/8-speed transmissions , dual clutch or automated ma nual transmissions, secondary axle disconnect, and aerodynamic improve ments can potentially (notwithstanding engineering constraints that , for example, preclude the application of aerodynamic improvements to some performance vehicles) be added at an average rate of 20 percent per year of a given manufacturer’s fleet ra ther than the 14-17 percent average annual phase-in caps used in the NPRM for these technologies. In the agency’s judgment, increased phase-in caps are appropriate for these transmission technologies, in part because the agency’s review of confidential product plans which indicated a higher than anticipated application rate of these technologies than ex isted at the time of the NPRM. Additionally, several manufactur ers indicated a high likelihoo d of significant usage of
dual clutch transmissions across their fleet of vehicles. The sec ondary axle disconnect technology was redefined for the final rule to consist of a somewh at basic, existing technology applicable only to 4 wheel-drive ve hicles (a smaller popul ation) rather than the NPRM-defined technology (which was a pplicable to both 4 and all wheel drive vehicles). The agency has also concluded that, because it has identified performance vehicles as such, and has estimated that ae rodynamic improvements are not applicable to these vehicles, aerodynamic dynamic improvement s can be applied more widely as long as they are applied consistent with vehicle redesign schedules. Furthermore, considering changes in manufacturers’ stat ed expectations regarding pros pects for diesel engines, the agency estimates that diesel engines could be added to as much as 4 percent of a manufacturer’s light truck fleet each year on average, rather than the 3 percent estimated in the NPRM. These changes in NHTSA’s estimates stem from the agency’s reevaluation of the status of these technologi es, as revealed by ma nufacturers’ plans and confidential statements, as well as other re lated comments submitted in response to the

NPRM.

Regarding comments that manuf acturers’ public statements re flect the ability to deploy technology more rapidly than reflected in the phase-in caps NHTSA applied in the NPRM, NHTSA notes that it did consider such statements. Combined with other information, these led the agency to c onclude that, as mentioned above, some technologies could, particularly in later years, be applied more widely than the agency had previously estimated. However, in their confidential statements to NHTSA, manufacturers are typically more candid a bout factors—both positive and negative—that affects their ability to depl oy new technologies than they are in public statements available to their competitors. Ther efore, NHTSA places greater weight on manufacturers’ confidential statements, es pecially when they are consistent with statements made by other manufacturers and/ or suppliers. NHTSA also observes that some organizations have exhibited a tendency to take manufacturers’ statements out of context, or overlook important caveats incl uded in such statements, which are largely used for marketing purposes.

Table V-8 below outlines the phase-in caps for each discrete technology for MY 2011. These phase-in caps, along with the expanded number and ty pes of vehicle subclasses, address the concerns raised by commenters and represent a substantial improvement inV-80

terms of consideration of th e factors affecting technology penetration rates over those used in the NPRM. Additional considerations regarding specific phase-in caps, including
nonlinear increases in these caps, are presented in the more detailed technology-bytechnology analysis summarized below.

For some of the technologies ap plied in the final rule, primar ily the valvetrain and diesel engine technologies, NHTSA has utilized comb ined phase-ins caps since the technologies are effectively the same from the standpoint s of engineering and implementation. The final rule represented diesel engines as two technologies that both result in the conversion of gasoline engine vehicles. The annual pha se-in caps for these tw o technologies, which are both set to a maximum of 3 percent for pa ssenger cars (4 percent for light trucks)
have been combined so that the maximum total application of either or both technologies to any manufacturers’ passenger car fleet is limited to 3 percent (not 6 percent). For example, if 3 percent of a manufacturers’ passenger car fleet has received diesel following combustion restart in a given y ear, diesel following turbocharging and downsizing will not be applied because the phase-in cap for diesels would have been reached. These combined phase-in caps are discussed below where applicable to each technology.

Table V-8a. Phase in caps from 2006 rule, 2008 NPRM, and current rule

Final Rule

MY2011

Low Friction Lubricants 25% 50% 50% Engine Friction Reduction 17% 20% 20% VVT - Coupled Cam Phasing (CCP) on SOHC 17% 20% 15% Discrete Variable Valve Lift (DVVL) on SOHC 17% 20% 15% Cylinder Deactivation on SOHC 17% 20% 9% VVT - Intake Cam Phasing (ICP) 17% 20% 15% VVT - Dual Cam Phasing (DCP) 17% 20% 15% Discrete Variable Valve Lift (DVVL) on DOHC 17% 20% 15% Continuously Variable Valve Lift (CVVL) 17% 20% 15% Cylinder Deactivation on DOHC 17% 20% 9% Cylinder Deactivation on OHV 17% 20% 9% VVT - Coupled Cam Phasing (CCP) on OHV 17% 20% 15% Discrete Variable Valve Lift (DVVL) on OHV 10% 20% 15%

Conversion to DOHC with DCP n.a n.a 9% Stoichiometric Gasoline Direct Injection (GDI) 3% 20% 3%

Combustion Restart n.a n.a. 0% Turbocharging and Downsizing 17% 20% 9% Exhaust Gas Recirculation (EGR) Boost n.a n.a. 0% Conversion to Diesel following CBRST 3% 3% 3% Conversion to Diesel following TRBDS 3% 3% 3% * Increased annually (in a linear manner) at the rate indicated Technology 2006

Rule* 2008

NPRM*V-81

Table V-8b. Phase in caps from 2006 rule, 2008 NPRM, and current rule

Final Rule

MY2011 Electric Power Steering 17% 25% 10% Improved Accessories 25% 25% 10% 12V Micro-Hybrid n.a. n.a. 3% Higher Voltage/Improved Alternator 17% 25% 10% Integrated Starter Generator 5% 3% 3% 6-Speed Manual/Improved Internals n.a. 17% 33% Improved Auto. Trans. Controls/Externals n.a. 25% 33% Continuously Variable Transmission 17% 17% 5% 6/7/8-Speed Auto. Trans with Improved Internals 17% 17% 50%

Dual Clutch or Automated Manual Transmission 17% 17% 20% Power Split Hybrid 5% 3% 0% 2-Mode Hybrid 5% 3% 0% Plug-in Hybrid n.a. 3% 0% Material Substitution (1%) 17% 17% 5% Material Substitution (2%) 17% 17% 5% Material Substitution (5%) 17% 17% 5% Low Rolling Resistance Tires 25% 25% 20% Low Drag Brakes 17% 25% 20% Secondary Axle Disconnect 17% 17% 17% Aero Drag Reduction 17% 17% 17% * Increased annually (in a linear manner) at the rate indicated Technology 2006

Rule* 2008

NPRM*V-82

D. Specific technologies considered for application and NHTSA’s estimates of
their incremental costs and effectiveness
1. What data sources did NHTSA evaluate? In developing the technology assumptions in the final rule, NHTSA, working with Ricardo, examined a wide range of data s ources and comments. We reexamined the
sources we relied on for the NPRM such as the 2002 NAS Report, the 2004 NESCCAF report developed for CARB by AVL and Martec, the 2006 EEA report and the EPA
certification data. We also considered more recent and updated sources of information and reports submitted to the NPRM docket, including the (1) Sierra Research report submitted by the Alliance as an attachment to its comments as another set of estimates for fuel economy cost and effectiveness, 146 (2) CARB’s response to as pects of that report, which was filed as supplemental comme nt on October 14, 2008, (3) the 2008 Martec Report, 147 which updated the Martec report on which the 2004 NESCCAF study was based, and the EPA Staff Technical Report, 148 which largely mirrored NHTSA’s NPRM
estimates.

The agency also evaluated confidential data from a number of vehicle manufacturers and technology component suppliers. 149 We note that vehicle ma nufacturers updated their product plans in response to NHTSA ’s May 2008 Request for Comment. 150

2. Individual technology descriptions and cost/effectiveness estimates (a) Gasoline Engine Technologies (i) Overview Most passenger cars and light trucks in the U.S. have gasoline-fueled spark ignition internal combustion engines. These engines move the vehicle by converting the chemical energy in gasoline fuel to useful mechanic al work output as shaft torque and power
delivered to the transmission and to the vehi cle’s driving wheels. Vehicle fuel economy is directly proportional to the efficiency of the engine. Two common terms are used to define the efficiency of an engine are (1) Brake Specific Fuel Consumption (BSFC),
which is the ratio of the mass of fuel used to the output mechanical energy; and (2) Brake Thermal Efficiency (BTE), which is the ratio of the fuel chemical energy, known as calorific value, to the output mechanical energy.

146 Sierra Research, “Attachment to Comment Regarding the NHTSA Proposal for Average Fuel Economy Standards Passenger Cars and light Trucks Model Years 2011-2015,” June 27, 2008. Available at Docket

No. NHTSA-2008-0089-0179.1.

147 Martec, “Variable Costs of Fuel Economy Technologies,” June 1, 2008. Available at Docket No.

NHTSA-2008-0089-0169.1.

148 EPA Staff Technical Report: Cost and Effectiven ess Estimates of Technologies Used to Reduce LightDuty Vehicle Carbon Dioxide Emissions. EPA420-R-08-008, March 2008.

149 The major suppliers that provided NHTSA with fu el economy cost and eff ectiveness estimates in response to our request for comments included Borg-Warner, Cummins, and Delphi, while Borg-Warner, Bosch, Coring, Cummins, Delphi, and Siemens also provided NHTSA with fuel economy cost and effectiveness estimates during confidential meetings.

150 Manufacturers that provided NHTSA with fuel economy cost and effec tiveness estimates in response to our request for comments include BMW, Chrysler, Daimler, Ford, GM, Honda, Nissan, and Toyota.V-83

The efficiency of an automotive spark igni tion engine varies considerably with the rotational speed and to rque output demanded from the engine. The most efficient operating condition for most current engine designs occurs around medium speed (30-50 percent of the maximum allowa ble engine rpm) and typically between 70-85 percent of maximum torque output at that speed. At th is operating condition, BTE is typically 33- 36 percent. However, at lower engine speed s and torque outputs, at which the engine operates in most consumer vehicle use and on standardized drive cycles, BTE typically drops to 20-25 percent.

Spark ignition engine efficiency can be improved by reducing the energy losses that occur between the point of combustion of the fu el in the cylinders to the point where that energy reaches the output crankshaft. Reductio n in this energy loss results in a greater proportion of the chemical energy of the fuel being converted into useful work. For improving engine efficiency at lighter e ngine load demand points, which are most relevant for CAFE fuel economy, the technolog ies that can be added to a given engine may be characterized by which type of ener gy loss is reduced, as shown in Table V-9
below.

Table V-9. Technology Characterization by Type of Loss Reduced



### Technology Heat Loss

Reduction Exhaust Energy

Reduction Gas Exchange

Reduction Friction

Reduction

Low Friction Lubricants 9
Engine Friction Reduction 9 VVT - Coupled Cam Phasing (CCP) on SOHC 9 Discrete Variable Valve Lift (DVVL) on SOHC 9 Cylinder Deactivation on SOHC 9 VVT - Intake Cam Phasing (ICP) 9 VVT - Dual Cam Phasing (DCP) 9 Discrete Variable Valve Lift (DVVL) on DOHC 9 Continuously Variable Valve Lift (CVVL) 9 Cylinder Deactivation on DOHC 9 Cylinder Deactivation on OHV 9 VVT - Coupled Cam Phasing (CCP) on OHV 9 Discrete Variable Valve Lift (DVVL) on OHV 9

Conversion to DOHC with DCP 9

Stoichiometric Gasoline Direct Injection (GDI) 9

Combustion Restart 9 Turbocharging and Downsizing 9 9 Exhaust Gas Recirculation (EGR) Boost 999

Conversion to Diesel 9 99

9 Represents area of primary influence

As Table V-9 shows, the main types of ener gy losses that can be reduced in gasoline engines to improve fuel economy are exhaust energy losses, engine friction losses, andV-84

gas exchange losses. Converti ng the gasoline engine to a dies el engine can also reduce
heat losses.

Exhaust Energy Loss Reduction Exhaust energy includes the kinematic and ther mal energy of the exhaust gases, as well as the wasted chemical energy of unburned fu el. These losses represent approximately 32 percent of the initial fuel chemical energy and can be reduced in three ways: first, by recovering mechanical or elec trical energy from the exhaus t gases; second, by improving the hydrocarbon fuel conversion; and th ird, by improving the cycle thermodynamic efficiency. The thermodynamic efficiency can be improved by either increasing the engine’s compression ratio or by operating with a lean air/fuel ratio. The latter is not considered to be at the emerging technology poi nt yet due to the non-av ailability of lean

NO

x aftertreatment, as discussed below. Ho wever, the compression ratio may potentially be raised by 1 to 1.5 ratios using stoi chiometric direct fuel injection.

Engine Friction Loss Reduction Friction losses can represent a significant propo rtion of the global losses at low load. These losses are dissipated through the cooling system in the form of heat. Besides via direct reduction measures, friction can also be reduced through downsizing the engine by means of increasing the engi ne-specific power output.

Gas Exchange Loss Reduction The energy expended while delivering the comb ustion air to the cylinders and expelling the combustion products is known as gas ex change loss, commonly referred to as pumping loss. The main source of pumping loss in a gasoline engine is the use of an inlet air throttle, which regulates engine output by controlling the pre- combustion cylinder air pressure, but is an inefficient way to achieve this pressure control. A more efficient way of controlling the cylind er air pressure is to modify the valve timing or lift. Another way to reduce the average pumping losses is to “downsize” the engine, making it run at higher loads or higher pressures.

As illustrated in Table V-9, several different technologies target pumping loss reduction, but it is important to note that the fuel c onsumption reduction from these technologies is not necessarily cumulative. Once most of the pumping work has been eliminated, adding further technologies that also target redu ced pumping loss will have little additional effectiveness. Thus, in the revised deci sion trees, the effectiveness value shown for additional technologies targeting pumpi ng loss depends on the existing technology combination already present on the engine.

(ii) Low Friction Lubricants (LUB) One of the most basic methods of reducing fu el consumption in gasoline engines is the use of lower viscosity engine lubricants. Mo re advanced multi-visco sity engine oils are available today with improved performance in a wider temperature band and with better lubricating properties. CAFE standards not withstanding, the trend towards lower friction lubricants is widespread. Within the next se veral year, most vehicl es are likely to useV-85

5W-30 motor oil, and some w ill use even less viscous oils, such as 5W-20 or possibly even 0W-20, to reduce cold start friction.

The NPRM reflected NHTSA’s belief that manu facturer estimates are the most accurate,
and it estimated that low friction lubricants could reduce fuel consumption by 0.5 percent for all vehicle types at an incremental cost of $3, which represented the mid-point of manufacturer estimates range, rounded up to th e next dollar. For the final rule NHTSA used the $3 cost from the NPRM, updated it to 2007 dollars, and ma rked it up to a retail price equivalent (RPE) of $5. Several manuf acturers commented conf identially that low friction lubricants could reduce fuel consumption by 0 to 1 percent, and the Alliance suggested 0.5 percent relative to the baseline fleet. Th ese comments confirm NHTSA’s NPRM effectiveness estimate, so NHTSA has retained it for the final rule.

Low friction lubricants may be applied to a ny class of vehicles. The phase-in for low friction lubricants is capped at 50 percen t for MY 2011. Honda commented that low
friction lubricants cannot be a pplied to engines that have no t been developed specifically
for them. 151 NHTSA understands that in some cas es there could be a need for design changes and durability verification to impl ement low friction lubricants in existing engines. However, aftermarket low friction lubricant products already exist, and have been approved for use in existing engines.

(iii) Engine Friction Reduction (EFR) Besides low friction lubricants, manufacturers can also reduce fricti on and improve fuel economy by improving the design of engine components and subsystems. Examples include improvements in low-tension pist on rings, roller cam followers, improved crankshaft design and bearings, material co atings, material substitution, more optimal thermal management, and piston and cylinder surface treatments.

In the NPRM, based on confidential manuf acturer data and the NAS, NESCCAF, and EEA reports, NHTSA estimated that friction reduction could incrementally reduce fuel consumption for all vehicles by 1 to 3 percent at a cost of $0 to $21 per cylinder resulting in cost estimates of $0-$84 for a 4-cyli nder, $0-$126 for a V-6, and $0-$168 for a V-8. For the final rule, NHTSA assumed there woul d be some cost asso ciated with reducing engine friction, since at a mi nimum engineering and validat ion testing is required, in addition to any new components required such as roller followers or improved bearings. Additionally some revised components, such as improved surface materials/treatments, piston rings, etc., have costs that vary by component size which need to account for the full range of engines under consideration in the rulemaking, from small displacement gasoline to large displacement diesel engines.

Considering the above, NHTSA relied on confidential manufacturer comments in response to the NPRM to determine a lo wer technology cost bound of $35 for a 4- cylinder engine and an upper cost of $195 fo r a 6 cylinder engine. These costs were marked up by a 1.5 RPE factor to arrive at per-cylinder costs of $13 to $49 which were used to establish costs based on cylinder count. Costs of $52 to $196 for a 4-cylinder

151 Docket NHTSA-2008-0089-0191.1.V-86

engine, $78 to $294 for a 6-cylinder engine, and $104 to $392 for an 8-cylinder engine
were used in the final rule.

Confidential manufacturer comments submitted in response to the NPRM showed an effectiveness range of 0.3 to 2 percent fo r engine friction reduction. Besides the
comments received another effectiveness esti mate, a November 2007 press release from Renault, claimed a gain of 2 percent over the NEDC cycle 152 from engine friction
reduction. 153 Based on the available sources, NHTSA established the fuel consumption effectiveness estimate for the final rule as 1 to 2 percent.

Engine friction-reducing tec hnologies are available from model year 2011 and may be applied to all vehicle subclasses. No lear ning factors were applied to costs as the technology has a loosely defined BOM which ma y in part consist of materials (surface treatments, raw materials) that are commodity based. As was the case in the NPRM, an average of 20 percent year-over-year phase -in rate starting in 2011 was adopted. As confirmed by manufacturers’ comments, NHTSA has maintained the NPRM position that engine friction reduction may only be appl ied in conjunction with a refresh cycle.

(iv) Variable Valve Timing (VVT) Variable valve timing (VVT) is a classification of valve-train designs that alter the timing of the intake valve, exhaust valve, or both, primarily to re duce pumping losses, increase specific power, and control the level of re sidual gases in the cylinder. 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 wh ere it is advantageous for certain engine operating modes.

VVT has now become a widely adopted tec hnology: for the 2007 m odel year, over half of all new cars and light trucks have engines with some meth od of variable valve timing. Therefore, the degree of further improvement across the fleet is limited by the level of valvetrain technology already implemented on the vehicles. Comments from Ford received in response to the NPRM indicate that many of its new and upgraded engines during the specified time period will launch w ith or upgrade to advanced forms of VVT,
which are discussed below. 154 Information found in the submitted product plans is used

152 Due to the advanced nature of many of the technologies discussed in the NPRM, and in an effort to find broad based rationale for the specific benefits of each technology type, reference data has been gathered that specifies fuel consumption benefits as measured on the NEDC test cycle. To make this conversion,
data from the International Council on Clean Tran sportation (ICCT) showed excellent correlation between CAFE test cycle results and NEDC test cycle results. While there was an offset in the linear best fit, the slope was nearly equal to 1; therefore, for this report, any percentage improvement found on the NEDC cycle will be assumed to be equivalent to gains found on the CAFE test cycle.

153 Renault press release, “Renault Introduces The Ecological, Economical Logan ‘Renault Eco2’ Concept At The Michelin Organized Challenge Bibendum, November 14, 2007. Available at http://www.renault.com/renault_com/en/images/ 15181%2015181_DP_logan_eco2_Shanghai_14_nov_DE F_GB_2_tcm1120-686305.pdf (las t accessed October 27, 2008 )

154 Docket No. NHTSA-2008-0089-0202.1, at 4.V-87

to determine the degree to which VVT tec hnologies have already been applied to particular vehicles to ensure the proper level of VVT technology, if any, is applied. There are three different implementation classi fications of variable valve timing: ICP (Intake Cam Phasing), where a cam phaser is used to adjust the timing of the inlet valves only; CCP (Coupled Cam Phasing), where a cam phaser is used to adjust the timing of both the inlet and exhaust valves equally; and DCP (Dual Cam Phasing), where two cam phasers are used to control the inlet and exhaust valve timing independently.

Each of these three implementations of VV T uses a cam phaser to adjust the camshaft angular position relative to th e crankshaft position, referred to as “camshaft phasing.” This phase adjustment results in changes to the pumping work required by the engine to accomplish the gas exchange process. The majority of current cam phaser applications use hydraulically actuated units, powered by engine oil pressure and managed by a
solenoid that controls the oil pressure supplied to the phaser. Electrically actuated cam phasers are relatively new, but are now in volume production with Toyota, which suggests that technical issu es have been resolved.

Honda commented that VVT is not applicable on existing engine designs that do not already contain these technologies due to durability, noise-vib ration-harshness (NVH), thermal, packaging, and other constr aints that require engine redesign.

1. Intake Cam Phasing (ICP) Valvetrains with ICP can modify the timing of the inlet valves by phasing the intake camshaft while the exhaust valve timing remain s fixed. This requires the addition of a cam phaser on each bank of intake valves on th e engine. An in-line 4-cylinder engine has one bank of intake valves, while V-configured engines have two banks of intake valves.

In the NPRM, NHTSA and EPA estimated that ICP would cost $59 per cam phaser or $59 for an in-line 4 cylinder engine and $119 fo r a V-type, for an overall cost estimate of $59 to $119, based on the NAS, NESCCAF, and EEA reports and confidential
manufacturer data. NHTSA received several updated cost estimates confidentially from manufacturers for ICP costs in response to th e NPRM that varied over a wide range from $35 to $300, and additionally looked to the 2008 Martec report for costing guidance. According to the 2008 Martec report, conten t assumptions for ICP costing include the addition of a cam phaser and oil control va lves at $25 and $10 respectively, per bank, which agreed with confidential manufacturer data received in response to the NPRM. These figures were then adjusted to include an incremental camshaft sensor per bank at $4, and an additional $2 increase to a ccount for an ECU upgrade as shown by confidential data. Using a ma rkup of 1.5 to yield a RPE valu e, the incremental cost for
ICP in the final rule is estim ated to be $61 per bank, resulting in a $61 charge for in-line engine configurations and $122 for V-engine configurations.

For fuel economy effectiveness values, NHTSA tentatively concluded in the NPRM that the incremental gain in fuel consumption fo r ICP would be 1 to 2 percent depending on engine configuration, in agreement with the NESCCAF study. Confidential manufacturer data submitted in response to the NPRM show ed a larger effectiven ess range of 1.0 to 3.4V-88

percent, although the majority of those estima tes fell at the lower end of that range. Based on the comments received, NHTSA retain ed the NPRM estimates of 1 to 2 percent incremental improvement in fuel consumption due to ICP.

ICP is applicable to all vehicl e classes and can be applied at the refresh cycle. For the final rule, NHTSA has combined the phase-i n caps for ICP, CCPS, CCPO and DCP and capped the joint penetration allowed at 15 pe rcent in MY 2011 with time-based learning applied.

2. Coupled Cam Phasing (CCPS and CCPO) Valvetrains with coupled (or coordinated) cam phasing can modify the timing of both the
inlet valves and the exhaust valves an e qual amount by phasing the camshaft of a single overhead cam (SOHC) engine or an overhead valve (OHV) engine. 155 For overhead cam engines, this requires the addition of a cam phaser on each bank of the engine. Thus, an in-line 4-cylinder engine has one cam phaser, while V-engines have two cam phasers. For overhead valve (OHV) engines, which have only one camshaft to actuate both inlet and exhaust valves, CCP is the only VVT implementation option available. 156

In the NPRM, NHTSA explained that for an OHV engine, the same phaser added for ICP would be used for CCP control, so the cost fo r CCP should be identical to that for ICP. For an OHV, since only one phaser would be required since only camshaft exists, NHTSA estimated the cost for CCP at $59 rega rdless of engine configuration, using the logic provided for ICP. For purposes of the fi nal rule, the logic for ICP also carries over to the cost estimates for CCP. Cost assumptions for CCP are the same as ICP resulting in RPE-adjusted costs of $61 for in-line S OHC or OHV engines and $122 for SOHC Vengine configurations, incremen tal to an engine without VVT.

For fuel economy effectiveness, NHTSA estim ated in the NPRM that the incremental gain in fuel consumption for CCP is 1 to 3 percent above that obtained by ICP, in agreement with the NESCCAF report and confidential manufacturer data. Confidential manufacturer data submitted in response to the NPRM also showed an effectiveness range of 1 to 3 percent for CCP, altho ugh Ford has publicly reported a 3.3 percent improvement for CCP when applied to its 5.4 liter 3-valve V8 engine (which has high
EGR tolerance due to the valve-maski ng effect with the 3-valve design). 157 Most engines
are not as EGR-tolerant and so will not achie ve as much effectiveness from CCP as the Ford engine. For purposes of the final rule , NHTSA essentially carried over the NPRM incremental effectiveness of applying the CCP technologies to be 1 to 3 percent.

155 Although CCP appears only in the SOHC and OHV br anches of the decision tree, it is noted that a single phaser with a secondary chain drive would allow CCP to be applied to DOHC engines. Since this would potentially be adopted on a limited number of DOHC engines NHTSA did not include it in that
branch of the decision tree.

156 It is also noted that coaxial camshaft developments would allow other VVT options to be applied to OHV engines. However, since they would potentially be adopted on a limited number of OHV engines
NHTSA did not include them in the decision tree.

157 Robert Stein, Tachih Chou, and Jeffrey Lyjak, “The Combustion System Of The Ford 5.4 L 3 Valve Engine,” Global Powertrain Congress 2003 - Advanced Engine Design & Performance, Sep 2003, Volume

24. Available at http://www.gpc-icpem.org/p ages/publications.html (l ast accessed Nov. 8, 2008)V-89

CCP can be applied to any class of vehicles at refresh. For the final rule, NHTSA has combined the phase-in caps for ICP, CCPS, CCPO and DCP and capped the joint penetration at 15 percent in NY 2011. Since th ese technologies are mature and in high volume, time-based learning factors are app lied. CCP can be applied to any class of
vehicles.

3. Dual Cam Phasing (DCP) The most flexible VVT design is dual (inde pendent) cam phasing, where the intake and exhaust valve opening and clos ing events are controlled independently. This option allows the option of controlling valve overla p, which can be used as an internal EGR strategy. At low engine loads, DCP creates a reduction in pumping losses, resulting in improved fuel consumption. Additionally, in creased internal EGR results in lower engine-out NO X emissions and improved fuel consumption. This fuel economy improvement depends on the residual tolerance of the combustion system, as noted in the CCP section above. Additional improvement s are observed at idle, where low valve overlap can result in improved combustion stability, potentially reducing idle fuel consumption.

In the NPRM, NHTSA estimated costs for DCP by building upon the cost estimates for ICP, where an additional cam phaser is added to control each bank of exhaust valves less
the cost of the EGR valve which can be deleted. This resulted in an NPRM cost range of $89 to $209. For purposes of the final rule, cost assumptions for DCP, which included inflation, were determined by essentially doubling the ICP hard ware, yielding an incremental cost of $61 per engine cylinder bank , over ICP. This translates to a cost of $61 for in-line engines and $122 for V-engine configurations, incremental to ICP technology.

For fuel economy effectiveness, NHTSA estim ated in the NPRM that the incremental gain in fuel consumption for DCP is 1 to 3 percent, in agreement with the NESCCAF report and confidential ma nufacturer data. Confidential manufacturer data received in response to the NPRM showed an effectiven ess range of 0.5 to 3.4 percent for DCP. Publicly available data from BMW 158 and Ford 159 show an effectiveness of 5 percent for DCP over engines without VVT, agreeing with the upper bounds for ICP and DCP combined. For purposes of the final rule, NHTSA concluded that the effectiveness for DCP should be at the upper end of the CCP ra nge due to the additiona l flexibility gained through independent control of intake and e xhaust valve timing, and therefore estimated an incremental fuel consumption reduction of 2 to 3 percent for DCP incremental to the 1 to 2 percent for ICP.

158 Meyer, BMW, “Turbo-Charging BMW’s Spray-Guided DI Combustion System – Benefits and Challenges,” Global Powertrain Congress, September, 2005, vol. 33. Available athttp://www.gpcicpem.org/pages/publications.html (last accessed Nov. 8, 2008)

159 Ulrich Kramer and Patrick Phlips, “Phasing Strategy For An Engine With Twin Variable Cam Timing,” SAE Technical Paper 2002-01-1101, 2002. Available at http://www.sae.org/technical/papers/2002-01- 1101. (last accessed Nov. 9, 2008)V-90

There are no class-specific a pplications of this technology an d DCP can be applied at the refresh cycle. For the final rule, NHTSA has combined the annual average phase-in caps for ICP, CCPS, CCPO and DCP and capped the joint penetration at 15 percent in MY 2011. The DCP technology is assumed to be produced at high volume, thus time-based learning is applied.

(v) Discrete Variable Valve Lift (DVVLS, DVVLD, DVVLO) DVVL systems allow the selection between tw o or three separate cam profiles by means of a hydraulically actuated m echanical system. By optimizing the cam profile for specific engine operating regions, the pump ing losses can be reduced by reducing the amount of throttling required to produce the desired engine power output. This increases the efficiency of the engine. DVVL is norma lly applied together with VVT control. DVVL is also known as Cam Profile Switching (CPS). DVVL is a mature technology
with low technical risk.

In the NPRM, based on the NESCCAF repor t and confidential manufacturer data, NHTSA estimated the incremental cost for DVVL at $169 to $322 compared to VVT depending on engine size, which included $25 for controls and associated oil supply needs. In response to the NPRM, confiden tial manufacturer comment s noted a cost range of $150 to $600 for DVVL on OHC engines. Si erra Research has noted costs ranging from $518 to $656 for DVVL including dual cam phasers on a mid-size car and $634 to $802 on trucks. 160 For purposes of the final rule, NHTSA has changed the order of the technologies in the decision trees which ha s changed how the DVVL costs are handled.

For the overhead cam engines, SOHC and DOHC, the costs were derived by taking $30 per cylinder for lost motion devices, adding a $4 incremental cost for a camshaft position sensor upgrade and $10 for an oil control valve on each engine cylinder bank, as indicated by the 2008 Martec report. This assu mes that one lost motion device is used to control either a single intake valve on an SOHC engine or a pair of intake valves on a DOHC engine, as was done in the NPRM. NHT SA’s independent review concurred with data in the 2008 Martec report because it contained the most complete published description of DVVL costs and it agreed with confidential manufacturer data received in response to the NPRM NHTSA adopted these co st estimates for the final rule, such that incremental costs for DVVLS and DVVLD, including a 1.5 RPE markup, are $201 for an in-line 4-cylinder engine, $306 for V-6 engine s, and $396 for V-8 engines. For overhead valve engines, OHV, the costs for V6 and V8 engines do not include the lost motion
devices and control hardwa re since DVVLO follows cylin der deactivation on the OHV decision tree path and employs similar lost motion devices. Rather, the DVVLO cost is for active engine mounts on V6 and V8 OHV engines which was based on $50 variable cost from Martec, adjusted to 2007 dollars and marked up with a 1.5 RPE factor to $76. For in-line 4-cylinder engines cylinder deac tivation is not allowed so the cost for DVVLO is the same as for DVVLS and DVVLD at $201.

For fuel economy effectiveness, in th e NPRM NHTSA estimated that DVVL could incrementally reduce fuel consumption by 0.5 to 3 percent compared to VVT.

160 Docket no. NHTSA-2008-0089-0179.1, p 59 and Docket no. NHTSA-2008-0089-0046, p. 52.V-91

Confidential manufacturer comments received in response to the NPRM indicated a 2 percent effectiveness for DVVL, while the Al liance commented that a two-step system with dual cam phasing could reduce fuel c onsumption by 6.3 percent, with 1.3 percent attributable to DVVL. Publicly-available estimates suggest an improvement over the NEDC test cycle of 8 percent for DCP with 2 stage inlet DVVL applied to a 1.6 liter DOHC 4 cylinder engine in a 1500 kg vehicle. 161 With the DCP system expected to deliver 5 percent effectivene ss, this suggests the DVVL syst em is giving approximately 3 percent. The comments received from manuf acturers and publicly available data are in alignment with independent review suggesting a range of 1 to 3 percent for overhead cam engines with VVT. NHTSA has therefore es timated an incremental reduction in fuel consumption for DVVLS and DVVLD of 1 to 3 percent for purposes of the final rule. On OHV engines, DVVLO is applied followi ng both VVT and cylinder deactivation, therefore the fuel consumption effectiveness has been reduced from 1 to 3 percent for OHC engines to 0.5 to 2.6 percent.

This technology may be applied to any class of vehicles with any kind of engine at the redesign cycle. For the final rule, NHTSA has combined the phase-in caps for DVVLS, DVVLD, DVVLO and CVVL and capped the join t penetration allowed at 15 percent in MY 2011 with time-based learning applied. Ot her technologies, such as continuously variable valve lift (CVVL), described below, will be implemented in place of DVVL in some applications where the fuel economy requirements dictate further optimization of the engine’s breathing characteri stics to improve efficiency.

(vi) Continuously Variable Valve Lift (CVVL) In CVVL systems, maximum valve lift is varied by means of a mechanical linkage, driven by an actuator controlled by the e ngine control unit. The valve opening and phasing vary as the maximum lift is changed; the relation depends on the geometry of the mechanical system. BMW has the most pr oduction experience with CVVL systems and has sold port-injected “Valve tronic” engines sinc e 2001. CVVL allows the airflow into the engine to be regulated by means of inlet valve opening reduction, which improves engine efficiency by reducing pumping losses fr om throttling the intake system further upstream as with a normally throttled engine.

Variable valve lift gives a further reduction in pumping losses compared to that which can be obtained with cam phase control onl y, with CVVL providing greater effectiveness than DVVL, since it can be fully optimized fo r all engine speeds and loads, and is not limited to a two or three step compromise. There may also be a small reduction in valvetrain friction when operating at low valv e lift. This results in improved low load fuel consumption for cam phase control with va riable valve lift as compared to cam phase control only. Most of the fuel economy effectiveness is achiev ed with variable valve lift on the inlet valves only.

161 Mark Sellnau and Eric Rask, “Two-Step Variable Valve Actuation For Fuel Economy, Emissions, and Performance, Delphi Research Labs, SAE 2003-01-0029. Available at http://www.sae.org/technical/p apers/2003-01-0029. (las t accessed Nov. 9, 2008)V-92

It is generally more difficult to achieve good cylinder-to-cylinder ai rflow balance at low
load with a CVVL valve-thro ttled engine due to the sens itivity of airflow to small differences in lift caused by manufacturing tolerances. BMW has reported mixture quality issues with CVVL and port fuel in jection, requiring a compromise on pumping work reduction to ensure good mixture quality. In addition, a small amount of throttling is necessary with CVVL to maintain the v acuum required for power brake assist, unless a separate vacuum pump is used. BMW calib rations maintain a small amount of inlet manifold depression on their “V alvetronic” engines to allow the brake servo to function, which reduces the efficiency gain from the system somewhat. Tumble air motion generated by the inlet port is not available in the cylinder at low valve lift, which has an
effect on combustion characterist ics. The high gas velocities at the valve seat generate high turbulence levels, but most of this has decayed by the time of ignition. This phenomenon could potentially lead to sub-op timal combustion characteristics, which would reduce the fuel consumption effectiveness of the technology.

In the NPRM, NHTSA estimated the cost fo r CVVL of $254 to $508 compared to VVT, with cost estimates varying from $254 fo r a 4-cylinder engine, $466 for a 6-cylinder engine, and $508 for an 8-cylinder engine, ba sed on confidential manufacturer data and the NESCCAF report, with more weight give n to the manufacturer data. As for DVVL, for purposes of the final rule, NHTSA relied primarily on the 2008 Martec report, because it contained the most complete publis hed description of CVVL costs and agreed
with confidential manufacture r data received in response to the NPRM. The system consists of 1 stepper motor per bank to c ontrol an eccentric shaft and the costs as described by Martec include dual cam phasi ng are $285 for an in-line 4-cylinder engine, $450 for a V-6 engine, and $550 for a V-8 engi ne. Applying a 1.5 RPE markup factor to these variable costs, and th en deducting $122 for the incremental cost of both ICP and DCP per bank, the incremental RPE cost is $306 for a 4-cylinder engine, $432 for a 6- cylinder engine and $582 for an 8-cylinder engine.

For fuel economy effectiveness, in the NPRM NHTSA estimated that CVVL could incrementally reduce fuel consumption by 1.5 to 4 percent compared to VVT, based on
confidential manufacturer da ta and the NESCCAF report. Confidential manufacturer comments received in response to the NPRM suggested a range of 3 to 7.4 percent incremental fuel consumption savings. NHT SA also found several sources reporting a 5 percent additional fuel consumption effec tiveness over the NEDC cycle when applying CVVL to an engine with dual cam phasers. 162 For purposes of the final rule, NHTSA has estimated the reduction in fuel consumpti on for CVVL at 1.5 to 3.5 percent over an engine with DCP. This estimate is lower that the effectiveness reported by BMW and allows the application of C VVL without the need for the high level of manufacturing complexity inherent in BM W’s “Valvetronic” engines.

162 See Johannes Liebl, Manfred Kluting, Jurgen Poggel, and Stephen Missy, BMW, “The New BMW 4- Cylinder Engine with Valvetronic Part 2: Thermodynamics and Functional Features,” MTZ Worldwide, July/Aug 2001, pp 26-29. See also Meyer, BMW, “Turbo-Charging BMW’s Spray-Guided DI Combustion System – Benefits and Challenges,” Global Powertrain Congress, Sept. 2005, vol. 33. Available at http://www.gpc-icpem.o rg/pages/publications.html (l ast accessed Nov. 8, 2008). See also Rainer Wurms, Philipp Lobbert, Stefan Dengler, Ralf Budack, and Axel Eiser, Audi, “How Much VVT Makes Sense?” Haus der Technik Conference on Variable Valve Control, Essen, Feb. 2007.V-93

There are no class specific a pplications of this technology, although it appears in only the DOHC portion of the decision tree. Due to th e changes required to implement DVVL on an engine the Volpe model allows it to be applied at redesign model years only with timebased learning applied. For the final rule, NHTSA has combined the phase-in caps for DVVLS, DVVLD, DVVLO and CVVL and cappe d the joint penetration allowed at 20
percent per year on average (15 percent in year one). There is no technical reason this technology could not be applied to all DOHC engines, but due to engineering resource limitations it is unlikely that CVVL will be applied to all engines, and that other technologies such as DVVL will be used in some instances.

(vii) Cylinder Deactivation (DEACS, DEACD, DEACO) In conventional spark-ignited engines, combus tion occurs in all cyli nders of the engine ( i.e. , the engine is “firing on all cylinders”), a nd throttling the airflow controls the engine output, or load. This is an inefficient method of operating the engine at low loads as pumping losses result from throttling. Cyli nder deactivation (DEAC) can improve engine efficiency by disabling or deactiv ating half of the cylinders when the load is less than half of the engine’s total torque capability, allowing the active cyli nders to operate at roughly twice the load level, and thereby in cur roughly half the pumping losses.

Simplistically, cylinder deactivation contro l strategy relies on setting maximum and minimum manifold absolute pressures (which are directly proportional to load) within which it can deactivate the cylinders. The engine operating range over which cylinder deactivation may be enabled is restricted by ot her factors as well, with noise, vibration, and harshness (NVH) being the primary concern; these restrictions all reduce the fuel economy effectiveness achievable with cylinder deactivation. In general, DEAC has very high sensitivity of efficiency gain relative to vehicle application, according to comments from Ford, Chrysler, the Alliance, and in confidential comments submitted in response to
the NPRM.

Manufacturers have stated that use of DEAC on 4 cylinder en gines would cause unacceptable NVH; therefore NHTSA has not ap plied cylinder deactiv ation to 4-cylinder engines. In addition, to a ddress NVH issues for V6 and V8 engines, active engine
mounts are included in the content list. No ise quality from both intake and exhaust systems has been problematic on some vehicle applications, and in some cases, has resulted in active exhaust systems soluti ons with an ECU-controlled valve.

The NPRM reported an incremental cost range for DEAC at $203 to $229, citing manufacturer data as the most credible, with the bill of materials including lost motion devices for each cylinder. The 2008 Martec report estimated the additional hardware necessary for cylinder deactiv ation ranging between $50 for the addition of two active engine mounts ($75 RPE using 1.5 RPE facto r) where DVVL already exists. This value has been adopted by NHTSA in the final rule so DEACS and DEACD costs are $75. For OHV engines NHTSA estimates the costs for DEACO as being $306 for V6 engines and $400 for V8 engines that are not already equipped with DVVL using assumptions for lostV-94

motion devices plus incremental costs for oil control valves and camshaft position
sensors as noted in the DVVL section.

For fuel economy effectiveness, in the NPRM NHTSA estimated that cylinder deactivation could reduce fuel consumption by 4.5 to 6 percent. As noted, DEAC has very high sensitivity of efficiency gain rela tive to vehicle application. Chrysler, for example, stated that the effectivenesss c ould range from 3 to 10 percent on the same engine depending on the speci fic vehicle application. 163 Confidential manufacturer comments received in response to the NPRM re ported a range of 3 to 7.5 percent. For the final rule, the incremental fuel consump tion effectiveness varies depending on which
branch of the decision tree it is on: for DOHC engines which are already equipped with
DCP and DVVLD there is little benefit that can be achieved since the pumping work has already been minimized and internal EGR rates are maximized, so the effectiveness ranges from 0 to 0.5 percent for DEACD; for SOHC engines which have CCP and DVVLS applied, NHTSA estimates a 2.5 to 3 per cent effectiveness for DEACS; and for OHV engines, which do not have VVT or VVL technologies, the effectiveness for DEACO ranges from 3.9 to 5.5 percent.

This technology may be applied only to V-6 and V-8 engines, as discussed above, and so does not apply to vehicle classes with I-4 engines. DEAC can be applied during a redesign or refresh model year with time-ba sed learning. NHTSA proposed to raise the phase-in cap for this technology to 20 percent per year in th e NPRM. For the final rule, NHTSA has combined the phase-in caps for DEACS, DEACD and DEACO and capped the joint average annual penetration allowed at 9 percent in MY 2011.

(viii) Conversion to Double Overhead Ca mshaft Engine with Dual Cam Phasing (CDOHC) This technology was named “Multi-valve Overhead Camshaft Engine” in the NPRM. Engines with overhead cams (OHC) and more than two valves per cylinder achieve increased airflow at high engi ne speeds and reductions of the valvetrain’s moving mass and enable central positioning of the spark pl ug. Such engines typi cally develop higher power at high engine speeds. In the NP RM, the model was generally not allowed to apply multivalve OHC technology to OHV engi ne, except where continuous variable valve timing and lift (CVVL) is applied to OHV engine. In that cas e, the model assumed conversion to a DOHC valvetrain, because a DOHC valvetrain is a prerequisite for the application of any advanced engine tec hnology over and above CVVL. Since applying CVVL to an OHV engine is the last improvement that could be made, it was assumed that manufacturers would redesign that engine as a DOHC and include CVVL as part of that redesign.

However, it appears likely that vehicles will still use overhead valve (OHV) engine with pushrods and one intake and one exhaust valve per cylinder into the next decade. For the final rule, NHTSA assumed that conversion of an OHV engine to a DOHC engine would more likely be accompanied by dual cam phasing (DCP) than by CVVL, since DCP application rates are higher than CVVL rates.

163 Docket No. NHTSA-2008-0089-0215.1.V-95

For V8 engines, the incremental cost to redesign an OHV engine as a DOHC with DCP was estimated as $746 which includes $415 fo r the engine conversion to DOHC per the 2008 Martec report and a 1.5RPE factor, plus $122 for an incremental cam phasing system (reflecting the doubling of cam shafts). For a V6 engine we estimated 75 percent of the V8 engine cost to convert to DOHC plus the same incremental coupled cam phasing cost to arrive at $590. For inline 4-cyli nder engines, 50 percent of the V8 engine
conversion costs were assumed and one a dditional cam phasing system yielding an incremental cost including a 1.5 RPE factor of $373.

For fuel economy effectiveness, NHTSA estim ated in the NPRM that the incremental gain in fuel consumption for conversion of an OHV engine with cylinder deactivation and CCP to a DOHC engine with CVVL at 1 to 4 percent, in agreement with the NESCCAF report and confidentia l manufacturer data. The fuel consumption benefit for converting an OHV engine to a DOHC engine with DCP is due largely to friction reduction according to a confid ential manufacturer comment. For the final rule the upper
bound stated in the NPRM was reduced becau se DCP will give less improvement than CVVL compared to an engine that alrea dy has cylinder deactivation and CCP applied.
NHTSA estimates the incremental fuel cons umption effectiveness at 1 to 2.6 percent independent of the number of engine cylinders.

There are no class-specific applications of this t echnology. In the NPRM, NHTSA proposed raising the phase-in cap to 20 percen t per year, but has concluded for the final rule that a 9 percent phase-in cap for MY 2011 is more consistent with manufacturers’
comments. No comments were received regarding phase-in ra tes of converting OHV engines to DOHC. The conversion from OHV to DOHC engine architecture with DCP is a major engine redesign that can be applied at redesign model years only with time-based learning applied.

(ix) Stoichiometric Gasoline Direct Injection (SGDI) In gasoline direct injection ( GDI) engines, fuel is injected into the cylinder rather than into the inlet manifold or inlet port. GDI allows for the compression ratio of the engine to be increased by up to 1.5 units higher than a port-injected engine at the same fuel
octane level. As a result of the higher compression ratio, the thermodynamic efficiency is improved, which is the primary reason fo r the fuel economy effectiveness with stoichiometric DI systems. The compression ra tio increase comes about as a result of the in-cylinder air charge cooling th at occurs as the fuel, which is sprayed directly into the combustion chamber, evaporates.

Volumetric efficiency in naturally-aspirated GDI engines can also be improved by up to 2 percent, due to charge cooling, which impr oves the full load torque. The improved full load torque capability of GDI engines can have a secondary effe ct on fuel economy by enabling engine downsizing, ther eby reducing fuel consumption.

Two operating strategies can be used in gasoline DI engines, characterized by the mixture preparation strategy. One stra tegy is to use homogenous charge where fuel is injectedV-96

during the intake stroke with a single injection. The aim is to produce a homogeneous air-fuel-residual mixture by the time of ignition. In this mode, a stoichiometric air/fuel
ratio can be used and the exhaust aftertreat ment system can be a relatively low cost, conventional three-way catalyst. Another strategy is to use stra tified charge where fuel is injected late in the compression stroke with si ngle or multiple injections. The aim here is to produce an overall lean, stratif ied mixture, with a rich area in the region of the spark plug to enable stable ignition. Multiple injections can be used per cycle to control the degree of stratification. Use of lean mixtures signifi cantly improves efficiency by reducing pumping work, but requires a relatively high cost lean NO

x trap in the exhaust aftertreatment system.

For purposes of this rulemaking, only homoge neous charge stoichiometric DI systems were considered, due to the an ticipated unavailability of lo w sulfur gasoline during the time period considered. This decision was supported by comments from Mercedes, which sells lean burn DI engines in other world markets, statin g that lean burn DI engines
cannot function in the absence of ul tra-low sulfur gasoline. Lean NO

x trap technologies require ultra-low sulfur gasoline to function at high conversion efficiency over the entire life cycle of a vehicle.

Gasoline DI systems effectiveness from the increased efficiency of the thermodynamic cycle. The fuel consumption effectiveness fr om DI technology is therefore cumulative to technologies that targ et pumping losses, such as th e VVT and VVLT technologies. The Sierra Research report stated that Sierra Research could not determine from the NPRM decision trees if VVLT technologi es were retained when SGDI was applied. To clarify, as the model progresses through the decisi on trees, technologies preceding SGDI are
retained in the cumulative effectiveness and cost.

In the NPRM, NHTSA estimated the incremen tal fuel consumption effectiveness for naturally aspirated SGDI 164 to be 1 to 2 percent. The Alliance commented that it estimated 3 percent gains in fuel efficiency, as well as a 7 percent improvement in torque, which can be used to mildly downsize the engi ne and give up to a 5.8 percent increase in efficiency. Other published literature re ports a 3 percent effectiveness for SGDI, 165 and another source reports a 5 percent im provement on the NEDC drive cycle. 166

Confidential manufacturer data submitted in response to the NPRM reported an efficiency effectiveness range of 1 to 2 per cent. For the final rule NHTSA has estimated, following independent review of all the sources referenced above, the incremental gain in fuel consumption for SGDI to be approximately 2 to 3 percent.

164 SGDI was referred to as GDI or SIDI in the NPRM.

165 Paul Whitaker, Ricardo, Inc., “Gasoline Engine Performance And Emissions – Future Technologies and Optimization,” ERC Symposium, Low Emission Combustion Technologies for Future IC Engines, Madison, WI, June 8-9, 2005. Available at http://www.erc.wisc.edu/symposiums/2005_Sympos ium/June%208%20PM/Whitaker_Ricardo.pdf (last accessed Nov. 9, 2008).

166 Stefan Trampert, FEV Motorentechnik GmbH, “Engine and Transmission Development Trends - Rising Fuel Cost Pushes Technology,” Symposium on International Automotive Technology, Pune, India, January

2007.V-97

Content assumptions for cost estimating of SGDI include no major changes to engine architecture compared to a port fuel inj ection engine, although cylinder head casting changes are required to incorpor ate the fuel injection system and the piston must change
as well to suit the revised combustion chambe r geometry. The fuel injection system utilizes an electrically-driven low pressure fu el pump to feed a high pressure mechanical pump, supplying fuel at pre ssures up to 200 Bar. A co mmon fuel rail supplies the injectors, which produce a highly atomized spra y with a Sauter Mean Diameter (SMD) of 15-20 microns, which compares to approxi mately 50 microns for a port injector.

In the NPRM, NHTSA estimated the following incremental cost ranges for applying SGDI: $122 to $420 for an inline 4-cylinder engine, $204 to $525 for a V6 engine, and $228 to $525 for a V8 engine. The Alliance commented that NHTSA had not accounted for the costs required to address NVH concerns associated with th e implementation of SGDI. For purposes of the final rule, all costs have been based upon side mount DI technology as these costs were determined in the 2008 Martec Report to be lower than center mount DI systems. An applied RPE f actor of 1.5 was used in all cases, and a NVH package was added to all engines in response to Alliance comments, providing incremental costs that ranged from $293 to $440 for an I4 engine, to $384 to $558 for a V6 engine and $512 to $744 for a V8 engine.

Homogeneous, stoichiometric DI systems are regarded as mature technology with minimal technical risk and are expected to be increasingly incorporated into manufacturers’ product lineups . Time-based learning has be en applied to this technology
due to the fact that over 1.5 million vehicles containing this technology are now produced annually. Due to the changes to the cylinder head and com bustion system and the control system development required to adopt SGDI technology, which are fairly extensive, SGDI can be applied only at redesign mode l years. There are no limitations on applying SGDI to any vehicle class. The phase-in cap for SGDI is applied at a 3 percent rate for
MY 2011 in order to account for the lead time required to incorporate SGDI engines.

(x) Combustion Restart (CBRST) Combustion restart allows “start-stop” functionality of DI engines through the implementation of an upgraded starter with bi-directional rotation to allow precise crankshaft positioning prior to subsequent fuel injection and spark ignition, allowing engine restart. This method of implementing engine st op/start functionality allows not only the fuel savings from not idling the engine , but also reduces fuel consumption as the engine speeds up to its operational speed. A Di rect Injection (DI) fuel system is required for implementation of this technology.

NHTSA has determined, upon independent re view, combustion rest art to be a high technical risk due to the following unresolve d issues. First, very high or very low ambient air temperatures may limit the ability to start the engine in the described manner. Although the starter motor can provide fail-safe starting capability in these temperature limited areas, strategies must be developed to manage the transitions. Additionally, a failsafe start strategy that recognizes failed at tempts and responds quickly enough has yet to
be demonstrated. The risk of missed start ev ents is currently relatively high, which isV-98

unacceptable from a production implementation pers pective. As a result, availability of this technology was assessed as beyond th e emerging technology time frame for MY

2011.

(xi) Turbocharging and Downsizing (TRBDS)
Forced induction in the form of turbocha rging and supercharging has been used on internal combustion engines for many years. Their traditional role has been to provide enhanced performance for high-end or sports car applications. However, turbocharging and downsizing can also be used to improve fuel economy. There is a natural friction reduction with a boosted downsized engine, becau se engine friction torque is primarily a function of engine displacem ent. When comparing FMEP (Friction Mean Effective Pressure – friction torque normalized by disp lacement) there is very little difference between the full size naturally-aspirated engi ne and the boosted downsized engine despite the higher cylinder pressure associated with higher BMEP. Turbocharging and downsizing can also reduce pumping losses (P MEP), because a turbocharged downsized engine runs at higher BMEP (Brake Mean E ffective Pressure) levels, and therefore higher manifold pressures, than a naturally aspira ted engine. The upper limit of BMEP level that can be expected from a naturally as pirated engine is approximately 13.5 Bar, whereas a turbocharged engine can produce BM EP levels in excess of 20 Bar. Engines
that are not downsized and boosted use a thro ttle to regulate lo ad, but this causes pumping losses as discussed previously. Thus, by using a small displacement engine with a turbocharger, the smaller engine works harder (higher cylinder load), which results in lower pumping loss since the throttle must be further open to produce the same road
power output.

Due to the incremental nature of the deci sion tree, engines having turbocharging and downsizing applied are assumed to have S GDI already applied. In boosted engines, SGDI allows improved scavenging of the cyli nder, which reduces the internal exhaust gas residual level and the charge temperature. This in turn allows a higher compression ratio to be used for a given fuel octane rating and can therefore improve the fuel consumption of boosted SGDI engines.

In most cases, a boosted downsized engine can replace a conventional naturally aspirated engine and achieve equivalent or greater (albeit at the e xpense of fuel economy) power and torque. However, there are some chal lenges associated with acceptance of a down sized boosted engine, including:

• Achievement of “seamless” power de livery compared to the naturally aspirated engine (no pe rceptible turbo lag);

• A complication in emissions regulatory compliance, because the addition of a turbocharger causes additional difficulty with catalyst light off due to the thermal inertia of the turbo itself;

• Potential issue with customer acceptance of smaller-displacement engines, given a common perception that only larger-displacement engines can be high-powered; and

• Additional base engine cost a nd vehicle integration costs.V-99

Manufacturers’ structural change s to the base engine are ge nerally focused on increasing the structure’s capacity to tolerate higher cyli nder pressures. NHTSA believes that it is reasonable to expect that the maximum cyli nder pressure would increase by 25 to 30 percent over those typical of a naturally aspira ted engine. Another c onsideration is that higher pressures lead to higher thermal loads.

One potential disadvantage of downsized a nd boosted engines is cost. Turbocharging systems can be expensive and are best combin ed with direct injection and other engine technologies. The Alliance expressed a related concern that the fuel economy effectiveness was based on the use of premium gr ade fuel in direct injection turbocharged engines, and argued that as th e baseline vehicles were not fu eled with premium gasoline, this gave the direct injection turboc harged engines an unrealistic advantage. 167 However, CARB stated in its comments that prem ium fuel is not necessary for use with turbocharged downsized engines and that substa ntial effectiveness are still available with regular fuel. 168 In fact, most turbocharged direct injection engines will have a compression ratio and calibration designed to give best performance on premium fuel, although they are safe to opera te on regular fuel. On regul ar fuel, the knock sensor output is used to allow the ECU to keep the engine safe by controlling boost and ignition timing. Maximum torque is reduced on th e lower octane fuel due to the ECU intervention strategy, but at part load, where knock is not an issue, the fuel economy will not be affected adversely relative to the esti mated effectiveness. Additionally, the driver
retains the choice of obtaini ng more performance by paying more for premium fuel and will still obtain stated fuel consumption effectiveness.

Nevertheless, the case for using downsized boosted engines has strengthened with the
wider introduction of direct injection gasoline engines. Downsized boosted engines with stoichiometric direct injec tion present minimal technical risk, although there have been only limited demonstrations of this t echnology achieving SULEV emission levels.

In the NPRM, NHTSA estimated that downs ized and turbocharged engines could incrementally reduce fuel consumption from 5 to 7.5 percent. CARB commented that Sierra Research in its presentation to the NAS committee on January 24, 2008, suggested
there is no carbon dioxide re duction potential for turboc harging and downsizing, but argued that this is not supported by other ve hicle simulation efforts nor by manufacturer plans to release systems su ch as the Ford EcoBoost. 169 The Alliance and Sierra Research, in contrast, commented that turbocharged and downsized engines do not improve fuel economy unless they are also equipped with DI fuel systems and using premium fuel. 170 NHTSA believes that turbocharging and downs izing, when combined with SGDI, offers benefits without the use of pr emium fuel as noted above. Confidential manuf acturer data suggests an incremental range of fuel c onsumption reduction of 4.8 to 7.5 percent for turbocharging and downsizing. Other pub licly-available sources suggest a fuel consumption benefit of 8 to 13 percent compared to current-production naturally-

167 Docket No. NHTSA-2008-0089-0179.1.

168 Docket No. NHTSA-2008-0089-0173.

169 Docket no. NHTSA-2008-0089-0173.4.

170 Docket no. NHTSA-2008-0089-0046, Docket no. NHTSA-2008-0089-0179.1.V-100

aspirated engines without friction reduction or other fuel economy technologies: a joint technical paper by Bosch and Ricardo suggesting an EPA fuel economy gain of 8 to 10 percent for downsizing from a 5.7 liter port inje ction V8 to a 3.6 liter V6 with direct injection; 171 a Renault report suggesting a 11.9 per cent NEDC fuel consumption gain for downsizing from a 1.4 liter port in jection in-line 4-cylinder engi ne to a 1.0 liter in-line 4- cylinder engine with direct injection; 172 and a Robert Bosch paper suggesting a 13 percent NEDC gain for downsizing to a turbocharged DI engine. 173 These reported fuel economy benefits show a wide range in large part due to the degree of vehicle attribute matching (such as acceleration pe rformance) that was achieved.

For purposes of the final rule, NHTSA estimated a net fuel consumption reduction of approximately 14 percent for a turbocharg ed downsized DOHC engine with direct injection and DCP over a baseline fixed-valve engine that does not incorporate friction reducing technologies. This e quates to an incremental fuel consumption reduction of 2.1 to 5.2 percent for TRBDS, which is incrementa l to an engine with SGDI and previously applied technologies ( e.g. , VVT and VVL) as defined by the decision tree. This wide range is dependent upon the decision tree path th at is followed or the configuration of the engine prior to conversion to TRBDS. The incremental fuel consumption benefit for TRBDS is estimated to range from 2.1 to 2.2 percent for V6 and V8 engines and from 4.5 to 5.2 percent for inline 4-cylinder engines. As explained, the incremental improvement from TRBDS must be added to the previous technology point on the decision tree. In the case of SOHC and OHV engines, for exampl e, moving to the TRBDS technology also assumes implementation of DOHC engine ar chitecture in addition to DCP and SGDI.

In the NPRM, NHTSA estimated that the co st for a boosted/downsized engine system would be $690 for small cars, $810 for larg e trucks, and $120 for all other vehicle classes, based on the NAS report, the EEA report, and confidentia l manufacturer data, which assumed downsizing allowed the removal to two cylinders in most cases, except for small cars and large trucks. CARB que stioned Martec’s cost estimates for turbocharging and downsizing, sp ecifically the credit for downs izing a V6 engine to an in-line 4 cylinder dropped from their estimate used in the NESCCAF report of $700 to $310 and the use of more expens ive hardware than some manuf acturers use. In response, NHTSA’s independent review of the cost to downsize a V6 DOHC engine to a I4 DOHC engine closely aligned with the 2008 Mart ec credit of $310, while the report for NESCCAF was not specific with regard to the assumptions used to construct that estimate. Additionally, confidential manufact urer data submitted in response to the NPRM provided a range for TRBDS with S GDI of $600 to $1,400 variable cost or $900 to $2100 RPE assuming a 1.5 markup factor. When comparing the confidential

171 David Woldring and Tilo Landenfeld of Bosch, and Mark J. Christie of Ricardo, “DI Boost: Application of a High Performance Gasoline Direct Injection Concept,” SAE 2007-01-1410. Available at http://www.sae.org/technical/papers/2007-01 -1410 (last accessed Nov. 9, 2008)

172 Yves Boccadoro, Loïc Kermanac’h, Laurent Siauve , and Jean-Michel Vincent, Renault Powertrain Division, “The New Renault TCE 1.2L Turbocharged Gasoline Engine,” 28th Vienna Motor Symposium, April 2007.

173 Tobias Heiter, Matthias Philipp, Robert Bosch, “Gaso line Direct Injection: Is There a Simplified, CostOptimal System Approach for an Attractive Future of Gasoline Engines?” AVL Engine & Environment Conference, September 2005.V-101

manufacturer cost range and the incremental RPE cost estimates for the final rule, it is important to realize the incremental cost fo r TRBDS does not include SGDI since it is considered a separate technology. 174

Some of the costs included in turbocharging and downsiz ing come from structural changes due to the higher cylinder pressures and increased cylinder temperatures, which also drive additional cooling requirements ( e.g. water-cooled charge air cooler, circulation pump, and thermostats) and requi re improved exhaust valve materials. High
austenitic stainless steel exhaus t manifolds and upgraded main bearings are some of the other hardware upgrades required. For purposes of the final rule, NHTSA used cost data from the 2008 Martec report, but constructed a bill of materials consistent with the incremental TRBDS technology as shown in th e decision trees and based on confidential
manufacturer data. For the ve hicle subclasses which have a baseline gasoline V8 engine, two turbochargers rated for 1050 ° C at $250 each were added, $270 was deducted for downsizing to a V6 from a V8 engine, $217 was added for engine upgrades to handle higher operating pressures and temperatures at, and a water-cooled ch arge air cooler was added at $280. The baseline SOHC engine was converted to a DOHC engine with 4 valves per cylinder at a variab le incremental cost of $92. Th e total variable costs summed to $819 and a 1.5 RPE factor was applied to arrive at $1,229 incremental cost to turbocharging and downsizing.

For the vehicle subclasses which have a ba seline gasoline V6 e ngine, a twin-scroll turbocharger rated for 1050 ° C was added at a cost of $350, $310 was deducted for downsizing to an I4 from a V6 engine, $160 was added for engine upgrades to handle higher operating pressures and temperatures, an d a water-cooled charge air cooler was added at $259. The baseline SOHC engine was converted to a DOHC engine with 4 valves per cylinder at a vari able incremental cost of $87. The total variable costs summed to $548 and a 1.5 RPE factor was applie d to arrive at $822 incremental cost to turbocharging and downsizing.

For the vehicle subclasses which have a ba seline gasoline I4 e ngine, a twin-scroll turbocharger rated for 1050 ° C was added at a cost of $350, $160 was added for engine upgrades to handle higher ope rating pressures and temperat ures, and a water-cooled charge air cooler was added at $259. The baseline SOHC engine was converted to a DOHC engine with 4 valves per cylinder at a variable incremental co st of $46. The total variable costs summed to $815 and a 1.5 RPE factor was applied to arrive at $1,223
incremental cost for turb ocharging and downsizing.

In summary, for the final rule NHTSA estimated TRBDS to have an incremental RPE cost of $1,223 for vehicle classes with a baseli ne in-line 4-cylinder engine downsized to a

174 NHTSA also examined the Jetta TDI as an example of a current vehicle model th at comes in both dieseland gasoline-engine form, but in attempting to do an apples-to-apples comparison with the nonturbocharged/downsized version , the SE, found indications that VW appears to be keeping the cost of the TDI down by removing other content ( e.g. , the SE has a sunroof, which normally costs around $1,000, while the TDI does not). Thus, NHTSA did not find VW’s price differential for the two versions of the Jetta to be convincing evidence of the actual cost of turbocharging and downsizing an engine.V-102

smaller I-4 engine which are: Subcomp act, Performance Subcompact, Compact and Midsize Car, and Small Truck. For vehicle cl asses with a baseline V6 engine that was downsized to an I4 engine the RPE cost is estimated at $822; these classes are the Performance Compact, Performance Midsize an d Large Car, Minivan and Midsize Truck.
The two vehicle classes with baseline V8 engines, Performance Large Car and Large Truck, were downsized to V6 turbocharged engines at an incremental RPE cost of $1,229.

Time-based learning has been applied to TRBDS because submitted product plan data indicated turbocharging and downsizing would already be at high volume in 2011. Due to the fact that a turbocharged and downsized en gine is entirely different than the baseline engine it can be applied only at redesign model years. The phase-in cap for TRBDS is applied at a 9 percent rate for MY 2011 in or der to account for the lead time required to incorporate TRBDS engines.

(xii) Cooled Exhaust Gas Recirculation Boost (EGRB) EGR Boost is a combustion concept that involv es utilizing EGR as a charge dilutant for controlling combustion temperat ures. Fuel economy is therefore increased by operating the engine at or near the stoichiometric air/ fuel ratio over the entire speed and load range and using higher exhaust gas residual levels at part load conditions. Further fuel economy increases can be achieved by increa sed compression ratio enabled by reduced knock sensitivity, which enables higher therma l efficiency from more advanced spark timing. Currently available tu rbo, charge air cooler, and EGR cooler technologies are sufficient to demonstrate the feasibility of this concept.

However, this remains a technology with a num ber of issues that still need to be addressed and for which there is no produc tion experience. EGR system fouling characteristics could be poten tially worse than diesel EGR system fouling, due to the higher HC levels found in gasoline exhaust. Turbocharger compressor contamination may also be an issue for low pressure EGR sy stems. Additionally, transient controls of boost pressure, EGR rate, cam phasers and in take charge temperature to exploit the cooled EGR combustion concept fully will re quire development beyond what has already been accomplished by the automotive industry. These are all “implementation readiness” issues that must be resolved prior to putting EGR Boost into volume production.

Because of these issues NHTSA did not consider EGR Boost in the NPRM, and consequently had no tentative conclusions w ith regard to its cost or fuel economy effectiveness. For purposes of the final rule, NHTSA found no evidence from commenters or elsewhere that these implement ation readiness issues could be resolved prior to MY 2011. Therefore, in the final rule, the phase-in cap for MY 2011 is zero.

(b) Diesel Engine Technologies Diesel engines, which currently make up a bout 0.27 percent of engines in the MY 2008 U.S. fleet, have several characte ristics that give them superi or fuel efficiency compared to conventional gasoline, spark- ignited engines. Pumping losses are much lower due to lack of (or greatly reduced) throttling. The diesel combustion cycle operates at a higherV-103

compression ratio, with a very lean air/fuel mixture, and turbocharged light-duty diesels typically achieve much higher torque levels at lower engine spee ds than equivalentdisplacement naturally-aspirated gasoline engines. Additionally, diesel fuel has higher energy content per gallon. 175

However, diesel engines, including those on the many diesel vehicles sold in Europe, have emissions characteristics that present ch allenges to meeting federal Tier 2 emissions standards. It is a significant systems-e ngineering challenge to maintain the fuel consumption advantage of the diesel engine while meeting U.S. emissions regulations, since fuel consumption is negatively im pacted by emissions reduction strategies. Emission compliance strategies for diesel vehi cles sold in the U.S. are expected to include a combination of combustion improve ments and aftertreatment. These emission control strategies are currently widely used in Europe, but will have to be modified due to the fact that U.S. emission standards, especially for NO

x , are much tighter than corresponding European standard s. To achieve U.S. Tier 2 emissions limits, roughly 45 to 65 percent more NO

x reduction is required compared to the Euro VI standards. Additionally, as discussed below, there may be a fuel consumption penalty associated
with diesel aftertreatment since extra fuel is needed for the aftertreatment, subsequently this extra fuel is not used in the combustion pr ocess of the engine that provides torque to propel the vehicle.

Nevertheless, emissions control technologies do exist, and will enable diesel engines to make considerable headway in the U.S. fleet in coming years. Several key advances in diesel technology have made it possible to reduce emissions coming from the engine prior to aftertreatment. These technologi es include improved fuel systems (higher pressures and more responsive injectors), advanced contro ls and sensors to optimize combustion and emissions performance, highe r EGR levels and EG R cooling to reduce

NO

x , lower compression ratios, and adva nced turbocharging systems.

The fuel systems on advanced diesel engines are anticipated to be of a High-Pressure Common Rail (HPCR) type with piezoelectric injectors that operat e at pressures up to 1800 Bar or greater and provide fa st response to allow multiple injections per cycle. The air systems will include a variable geometry turbocharger for 4-cylinder inline engines with charge-air cooling and high-pressure and low-pressure EGR loops with EGR coolers. For V-6 or V-8 engines the air systems will employ series sequential turbocharging with one variable geometry turbocha rger and one fixed geometry turbocharger.

As suggested above, the traditional 3-way catalyst aftertreatment found on gasolinepowered vehicles is ineffective due to the le an-burn combustion of a diesel. All diesels will require a diesel particulate filter (DPF) , a diesel oxidation catalyst (DOC), and a NO

x reduction strategy to comply with Tier 2 emissions standards. The most common NO

x reduction strategies include the use of lean NO

x traps (LNT) or selective catalytic reduction (SCR), which are outlined below.

175 Burning one gallon of diesel fuel produces about 11 percent more carbon dioxide than gasoline due to the higher density and carbon to hydrogen ratio.V-104

(i) Diesel Engine with Lean NO
x Trap (LNT) Catalyst After-Treatment
A lean NO

x trap operates, in principle, by storing NO

x (NO and NO 2 ) when the engine is running in its normal (lean) state. When the control system determines (via mathematical
model or a NO

x sensor) that the trap is saturated with NO

x , it switches the engine into a rich operating mode or may in some cases inje ct fuel directly into the exhaust stream to produce excess hydrocarbons that act as a re ducing agent to convert the stored NO

x to N 2 and water, thereby “regenerating” the LNT and opening up more locations for NO

x to be
stored. LNTs are sensitive to sulfur deposits that can re duce catalytic performance, but periodically undergo a desulfur ization engine-operating mode to clean it of sulfur buildup.

The fuel consumption penalty associated w ith aftertreatment systems, including both DPF and LNT, is taken into acc ount in the reported values. In the case of the DPF, extra fuel is needed to raise the temperat ure of the DPF above approximately 550 ° C to enable active regeneration. A similar process is need ed to regenerate the LNT, but instead of being used to remove particulates and raise the temperature, the excess fuel is used to provide a fuel-rich condition at the LNT to convert the trapped NO

x on the LNT to nitrogen gas. The estimated fuel consumpti on penalty on the CAFE te st cycle associated with the LNT aftertreatment system is 5 pe rcent on the EPA city cycle and 3 percent on the highway cycle, as descri bed in the report to the EPA. 176

In order to maintain equivalent performance to comparable gasoline-engine vehicles, an inline 4-cylinder (I-4) diesel engine with displacement varying around 2 liters to meet vehicle performance requirements was assumed for Subcompact, Performance Subcompact, Compact, and Midsize Passenger Car and Small Truck vehicle subclasses,
and it was also assumed that these vehicles would utilize LNT aftertreatment systems.

In the NPRM, NHTSA estimated that LNT-base d diesels could incrementally reduce fuel consumption by 8 to 15 percent at an incremental RPE cost of $1,500 to $1,600 compared to a direct injected turbocharg ed and downsized spark-ignition engine, in agreement with confidential manufacturer data . These costs were based on a “bottom up” cost analysis that was performed with EPA, which then subtracted the costs of all previous steps on the decision tr ee prior to diesel engines.

Comments submitted in response to th e NPRM including both manufacturers’
confidential data and non -confidential data sources for dies el engines was in the range of 16.7 percent to 26.7 177 percent fuel consumption benefit over a baseline gasoline engine at a variable cost of $2,000 to $11,200. Confidentially submitted diesel cost and effectiveness estimates generally did not diffe rentiate between car a nd truck applications, engine size and aftertreatement systems l eading to large ranges for both cost and

176 Ricardo, “A Study of Potential Effectiveness of Carbon Dioxide Reducing Vehicle Technologies, Revised Final Report,” at 62. Available at http://www.epa.gov/otaq/technology/420r08004a.pdf (last accessed Oct. 4, 2008).

177 The 26.7 percent fuel consumption reduction is a maximum estimate cited in a June 2008 Sierra Research report (Docket No. NHTSA-2008-089-0179.1) for a CAFE estimate in a midsize car, whereas an April 2008 Sierra report (Docket No. NHTSA-2008-089-0046) cites a maximum estimate of 22.4 percent for the same vehicle class; NHTSA was unab le to discern why the estimates differed.V-105

effectiveness estimates. Additionally, most of th e costs appeared to be stated as variable costs not RPE but this was not always completely discernible.

For purposes of the final rule, NHTSA estimated the net fuel consumption benefit for an I-4 diesel engine with LNT aftertreatme nt to be approximately 20 to 26 percent improvement over a baseline gasoline engine . This equates to a 5.3 to 7.7 percent improvement for DSLT, which is incrementa l to a turbocharged downsized gasoline engine (TRBDS) with EGRB, and a 15.0 to 15.3 percent incremental improvement for DSLC, which is incremental to a gasoline en gine with combustion restart (CBRST.) The 2008 Martec report was relied upon for cost estima tes and the diesel cost was adjusted by removing the downsizing credit and applying a 1.5 RPE marked up factor to arrive at a cost of $4007 compared to a baseline gasoline engine. This results in an incremental RPE cost of $1,567 to $1,858 for DSLT and $2,963 to $3,254 for DSLC. NHTSA’s independent review concurred with all the costs in this bill-of-material-based cost analysis.

A large part of the explanation for the cost increase since the NPRM is the dramatic increase in commodity costs for the aftertr eatment systems, namely the platinum group metals. The updated cost estimates of Martec 2008 and others reflec t the rise of global
costs for raw materials since Martec 2004 and ot her prior referenced cost estimates were conducted. As described in Martec 2008, engine technologies employing high temperature steels or catalysts with cons iderable platinum group metals usage have experienced tremendous inflation of raw ma terial prices. These updated estimates account for current spot prices of platinum and rhodium which have demonstrated cost inflation amounting to between 300 a nd 750 percent of global prices. 178

(ii) Diesel Engine with Selective Ca talytic Reduction (SCR) After-Treatment An SCR aftertreatment system uses a reduc tant (typically, ammonia derived from urea) that is continuously injected into the exhaust stream ahead of the SCR catalyst.
Ammonia combines with NO

x in the SCR catalyst to form N 2 and water. The hardware configuration for an SCR system is more comp licated than that of an LNT, due to the onboard urea storage and delivery system (whi ch requires a urea pump and injector into the exhaust stream). While a rich engi ne-operating mode is not required for NO

x reduction, the urea is typically inje cted at a rate of 3 to 4 percent of the fuel consumed. Manufacturers designing SCR systems intend to align urea tank ref ills with standard maintenance practices such as oil changes.

The fuel consumption penalty associated with the SCR aftertreatment system is taken into account in the values reported here. Similar to the LNT system, extra fuel is needed to warm up the SCR system to an effective operating temperature. The estimated fuel consumption penalty on the CAFE test cycl e associated with the SCR aftertreatment system is 5 percent on the EPA city cycle and none on the highway cycle, as described in

178 Martec, “Variable Costs of Fuel Economy Technologies,” June 1, 2008, at 13-20. Docket No. NHTSA2008-0089-0169.1

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the report to the EPA. 179 A recent report, however, s uggests a fuel economy benefit associated with the use of a SCR system, based on the supposition that the engine calibration is shifted towards improved fuel consumption and more of the NO

x reduction is being handled by the SCR system. 180 Nevertheless, since this benefit is not yet proven for high-volume production, it has not been applied for purposes of the final rule.

In order to maintain equivalent performance to comparable gasoline-engine vehicles, a V6 diesel engine, with displacement varying around 3 liters was assumed for Performance Compact, Performance Midsize, Large Passe nger Car, Minivan, a nd Midsize Truck. A V8 diesel engine, with displacement varying around 4.5 liters to meet vehicle performance requirements, was assumed for Large Truck an d Performance Large Car vehicle classes.
It was also assumed that these classes w ith V-6 and V-8 diesel engines utilize SCR aftertreatment systems instead of LNT.

In the NPRM, NHTSA estimated incrementa l fuel consumption reduction for diesel engines with an SCR system to range from 11 to 20 percent at an incremental RPE cost of $2,051 to $2,411 compared to a direct inje cted turbocharged and downsized sparkignition engine. These costs were based on a “bottom up” cost analysis that was performed with EPA, which then subtracted th e costs of all previous steps on the decision tree prior to diesel engines.

As explained above for LNT, confidentia l manufacturer and non-confidential comment data submitted in response to the NPRM for diesel engines was in the range of 16.7 percent to 26.7 percent fuel consumption be nefit over a baseline gasoline engine at variable cost of $2,000 to $11,200 with no detail about the aftertreatme nt, engine size or application. Additionally, Ricardo’s vehi cle simulation work for EPA found an
incremental fuel economy benefit of 19 percent for a 4.8L diesel in a Large Truck. 181 However, when the baseline 4-speed automatic transmission shift and torque converter lockup scheduling was optimized for the diesel engine, an additional 5 percent fuel economy benefit was obtained to yield an increm ental benefit for a diesel of 24 percent. As noted in the report on page 84, however, this does not represent an optimized result, as only the final packages complete with al l technologies were optimized. Nevertheless,
this is a reasonable estimate for diesel e ngine fuel economy benefit over a baseline gasoline engine with coordinated cam phasing (CCP). This estimate did not have the aftertreatment penalty, however, so applying th e 5 percent penalty asso ciated with diesel oxidation catalyst, diesel particulate filter , and SCR aftertreatment brings the fuel

179 Ricardo, “A Study of Potential Effectiveness of Carbon Dioxide Reducing Vehicle Technologies, Revised Final Report,” at 62. Available at http://www.epa.gov/otaq/technology/420r08004a.pdf (last accessed Oct. 4, 2008).

180 Timothy V. Johnson, “Diesel Emission Control in Re view,” Society of Automotive Engineers Technical Series, 2008-01-0069, 2008. Available at http://www.sae.org/techni cal/papers/2008-01- 0069 (last accessed Nov. 9, 2008).

181 Ricardo, “A Study of Potential Effectiveness of Carbon Dioxide Reducing Vehicle Technologies, Revised Final Report,” Table 7-9 shows incremental fuel economy and CO2 benfits for Truck with technology package 11, p. 87. Available at http://www.epa.gov/otaq/technology/420r08004a.pdf (last accessed Oct. 4, 2008).V-107

economy benefit for diesel engine with aftert reatment down to 19 percent, which is equal to a 16 percent fuel consumption benefit.

For purposes of the final rule, NHTSA estimat ed the net fuel consumption benefit for a V-6 diesel engine with SCR aftertreatme nt to be approximately 20 to 26 percent improvement over a baseline gasoline engine . This equates to a 4.0 to 7.7 percent improvement for DSLT, which is incrementa l to a turbocharged downsized gasoline engine (TRBDS) with EGRB, and a 9.9 to 13.1 percent incremental improvement for DSLC, which is incremental to a gasoline en gine with combustion restart (CBRST.) The 2008 Martec report was relied upon for cost estima tes and the diesel cost was adjusted by removing the downsizing credit and applying a 1.5 RPE marked up factor to arrive at a cost of $5,603 compared to a baseline gasoline engine. This results in an incremental RPE cost of $3,110 to $3,495 for DSLT and $4,105 to $4,490 for DSLC. NHTSA’s independent review concurred with all the costs in this bill-of-material-based cost analysis for V-6 engines.

NHTSA estimated the net fuel consumption be nefit for a V-8 diesel engine with SCR aftertreatment to be approximately 19 to 25 percent improvement over a baseline gasoline engine. This equates to a 4.0 to 6.5 percent improvement for DSLT, which is incremental to a turbocharged downsized gasoline engine (TRBDS) w ith EGRB, and a 10.0 to 12.0 percent incremental improvement for DSLC, which is incremental to CBRST. The 2008 Martec report was relied upon for cost esti mates and the diesel cost was adjusted by removing the downsizing credit and applying a 1.5 RPE marked up factor to arrive at a cost of $7,002 compared to a baseline gasoline engine. This results in an incremental RPE cost of $3,723 to $4,215 for DSLT and $5,125 to $5,617 for DSLC. NHTSA’s independent review concurred with all the costs in this bill-of-material-based cost analysis for V-8 engines.

The diesel engine with SCR has an incremen tal cost that is signi ficantly higher for the
final rule than the NPRM. NHTSA believe s the increase is explained by the improved accuracy of the final rule an alysis which relied on the updated cost estimates from the 2008 Martec Report as described previously 182 . In addition, comments from the Alliance suggested that the incremental diesel cost for a midsize car was $6,198 and $7,581 183 for a pickup truck.

The economic breakeven point for diesel engine aftertreatment options is based on public
information 184 and on recent discussions that NHT SA and EPA have had with auto

182 Martec, “Variable Costs of Fuel Economy Technologies,” June 1, 2008, at 13-20. Docket No. NHTSA2008-0089-0169.1.

183 These cost estimates are taken from the April 20 08 Sierra Research report (Docket No. NHTSA-2008- 089-0046). A June 2008 Sierra Research report (Docket No. NHTSA-2008-089-0179.1) contained lower estimates of $5,947 and $7,271 for the same vehicles ; NHTSA was unable to di scern the reason for the
difference.

184 Timothy V. Johnson, “Diesel Emission Control in Review,” Diesel Engine-Efficiency and Emissions Research (DEER) Conference, Detroit, MI, August 20-24, 2006. Available at http://www1.eere.energy.gov/vehiclesandfuels/pdfs/ deer_2006/session2/2006_deer_johnson.pdf (last accessed Nov. 9, 2008). See also Tim Johnson, “Diesel Engine Emissions and Their Control,” PlatinumV-108

manufacturers and aftertreatment device manuf acturers. NHTSA explained in the NPRM that it had received strong indications th at LNT systems would probably be used on smaller vehicles while the SCR systems would be used on larger vehicles and trucks. The economic break-even point between LNT and SCR is dependent on the quantity of catalyst used, the market price for the metals in those catalysts, and the cost of the urea injection system. The NPRM estimated th at the breakeven point would occur around 3 liters engine displacement, based on di scussions with auto manufacturers and
aftertreatment device manufacturers. Thus , NHTSA tentatively c oncluded that it would be cheaper to manufacturer diesel engines sm aller than 3 liters with an LNT system, and that conversely, it would be cheaper to manufacturer diesel engines larger than 3.0 liters with a SCR system. No comments were submitted to NHTSA regarding the breakeven point between a LNT and SCR system. Howeve r, according to one source of recently published data the breakeven point occurs between 2.0 to 2.5L. 185 Considering that continuing developments are being made in this area and the wide range of precious metal content required, NHTSA believes that an economic breakeven point of 2 to 3 liters
is reasonable and that other f actors will strongly influence whic h system is chosen by any given vehicle manufacturer.

Cummins commented that LNT systems should be considered for more than just the compact and subcompact vehicles, and stated that a number of large vehicles and trucks currently use LNT. Cummins argued that a LNT after-treatment system can be a costeffective technology on both small and larger engines. For the final rule, NHTSA assumed the use of a LNT after-treatment system for three additional vehicle subclasses compared to the NPRM. However, followi ng the rationale explained in the preceding paragraph, the SCR type after-tr eatment system is assumed for larger vehicle subclasses. As is the case with all technologies in the analysis, technology application assumptions are based on the general unders tanding of what a manufactur er could do in response to meeting emissions compliance but other manufac turer specific factor s will dictate the actual technology applications.

In the NPRM, NHTSA assumed a 3 percent phase in rate per y ear for diesel technologies. For the final rule, passenger cars, as defi ned by the technology class, retained the 3 percent combined (for DSLT and DSLC) phase-i n cap. However, diesel technologies for truck technology classes were allowed to be applied at a 4 percent combined (for DSLT and DSLC) phase-in cap to account for the higher applica tion rates observed in the submitted product plans and diesel’s favorable characteristics in truck applications. Volume-based learning was assumed for the NPRM, however, confidential product plans
indicated that this techno logy would be in high-volume in the 2011 time frame, thus time-based learning was assumed for the final rule . For the final rule, diesel technologies can only be applied at redesign, whic h is consistent with the NPRM.

(c) Transmission Technologies

Metals Review, 52, at 23-37 (2008). Available at http://www.platinu mmetalsreview.com/dynamic/article/view/ 52-1-23-37 (last acce ssed Nov. 9, 2008)

185 Id

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NHTSA has also reconsidered the way it app lies transmission technologies in the Volpe model to obtain increased fuel savings. The revised decision tree for transmission technologies reflects the fact that baseline vehicles now in clude either 4- or 5-speed automatic transmissions, given that many manufacturers are already employing 5-speed automatic transmissions or are going directly to 6-speed automatics. 186 The decision tree in the final rule also combines “aggressive shift logic” and “ear ly torque converter lockup,” although the NPRM considered them separately, because NHTSA concluded upon further review that the tw o technologies could be optim ized simultaneously due to the fact that adding both of them primarily required only minor modifications to the
transmission or calibration software. Cost and effectiveness numbers have also been thoroughly reexamined, as have learning ra tes and phase-in caps, based on comments
received. The section below describes each of the transmission technologies considered.

(i) Improved Transmission Co ntrols and Externals (IATC) During operation, an automatic transmission’s controller ma nages the operation of the transmission by scheduling the upshift or dow nshift, and locking or allowing the torque converter to slip based on a preprogrammed sh ift schedule. The shift schedule contains a number of lookup table functions, which defi ne the shift points and torque converter lockup based on vehicle speed and throttle position, and other parameters such as temperature. Aggressive sh ift logic (ASL) can be employed in such a way as to maximize fuel efficiency by modifying the sh ift schedule to upshift earlier and inhibit downshifts under some conditions, which reduc es engine pumping losses and engine friction as noted in the gas engine se ction. Early torque converter lockup 187 in conjunction with ASL can further improve fu el economy by locking the torque converter sooner, thus reducing inherent torque converter slippage or losses. As discussed above, the NPRM separated these two technologies, but they are combined for purposes of the
final rule since the calibration software can be optimized for both functions simultaneously.

Calibrating the transmission shift schedule to improve fuel consumption reduces the average engine speed and increases the av erage engine load, which can lead to a perceptible increase in engine harshness. The degree to which the engine harshness can
be increased before it becomes noticeable to the driver is strongly influenced by characteristics of the vehicle, and although it is somewhat subjective, it always places a limit on how much fuel consumption can be improved by transmission control changes. The Alliance agreed in its comments that ASL can be used effectively to reduce throttling losses, but at the expense of noise-vibrati on-harshness (NVH) and drivability concerns.
The Alliance also commented that losses in the torque converter typically make
automatic transmissions less efficient than manual transmissions, and suggested that efficiency can be improved by mechanically “l ocking up” the torque converter earlier or

186 Confidential product plans indicate that future products manufactured within the rulemaking period may not go from 4- or 5-speed transmission, but will inst ead introduce 6- or 7-speed automatic transmissions as replacements.

187 Although only modifications to the transmission calibration software are considered as part of this technology, very aggressive early torque converter lock up may require an adjustment to damper stiffness and hysteresis inside the torque converter. Internal transmission hardware changes associated with this technology are addressed in 6/7/ 8-Speed Automatic Transmission with Improved Internals section.V-110

replacing the torque converter with a fric tion clutch of the type used on a manual transmission. Simply replacing a torque converter with a friction clutch, however, ignores the torque multiplication that torq ue converters provide at vehicle launch.

In the NPRM, NHTSA estimated that aggressive shift logic could incrementally reduce fuel consumption by 1 to 2 percent at an incremental cost of $38 and early torque converter lockup could incrementally reduce fuel consumption by 0.5 percent at a $30
cost for the calibration effort . Confidential manufacturer comments suggested that less aggressive shift logic must be employed on vehicles with low acceleration reserve, but that a 1-3 percent improvement in fuel econom y was attainable on vehicles with adequate
acceleration reserve.

For the final rule, NHTSA combined aggressi ve shift logic and early torque converter lockup into the IATC technology with an eff ectiveness estimate of 1.5 to 2.5 percent in agreement with most confidentia l manufacturer estimates. As aggressive shift logic and early torque converter lockup are both achievable with a similar calibration effort, the incremental cost for improved automatic tran smission controls used the higher value of $38, converted this value to 2007 dollars, and applied a 1.5 RPE markup factor to arrive
at an incremental cost estim ate of $59 for the final rule.

The IATC technology is considered to be av ailable at the start of the 2011 model year, and as was the case in the NPRM, NHTSA c onsiders that it can be applied during a refresh model year since NVH concerns must be addressed. The technology is applicable
to all vehicle subclasses and NHTSA determ ined IATC type technologies will be high
volume within the 2011 time frame so time-ba sed learning is assumed, with a phase-in cap for MY 2011 of 33 percent.

(ii) Automatic 6-, 7- and 8- Speed Transmissions (NAUTO) Having more “speeds” on a transmission ( i.e. , having more gear ratios on the transmission) gives three effects in terms of vehicle performance and fuel economy. First, more gear ratios allow deeper 1 st and 2 nd gear ratios for improved launch performance, or increased acceleration. Sec ond, a wider ratio spread also offers the ability to reduce the steps betw een gear ratios, which allows the engine to operate closer to optimum speed and load efficiency region. And third, a reduction in gear ratio step size improves internal transmission losse s by reducing the sliding speeds across the clutches, thus reducing the viscous drag loss generated between two surfaces rotating at different speeds. Bearing spin losses are al so reduced as the differential speed across the two bearing surfaces is reduced. This allows th e engine to operate at a reduced load level to improve fuel economy.

Although the additional gear ratio s improve shift feel, they al so introduce more frequent shifting between gears, which can be pe rceived by consumers as bothersome. Additionally, package space limitations prevent 7- and 8-speed automatics from being applicable to front wheel drive vehicles.V-111

Comparison between NPRM and final rule cost and effectiveness estimates are somewhat complicated by the revisions in the decision trees and technology assumptions. In the NPRM, NHTSA estimated that 6-, 7- and 8- speed transmissions could incrementally reduce fuel consumption by 0.5 to 2.5 percen t at an incremental cost of $76 to $187, relative to a 5-speed automatic transmission, a technology not used in the final rule decision tree, and the incremental cost for a 4-speed to a 5-speed automatic transmission (again no longer considered in the final rule) was estimated to be $76 to $167.

In response to NHTSA’s request for info rmation, confidential manufacturer data projected that 6-speed transmissions could in crementally reduce fuel consumption by 0 to 5 percent from a baseline 4-speed automatic transmission, while an 8-speed transmission could incrementally reduce fuel consumption by up to 6 percent from a baseline 4-speed automatic transmission. The 2008 Martec report estimated a cost of $323 (RPE adjusted) for converting a 4-speed to a 6-speed transmi ssion and a cost of $638 (RPE adjusted) for converting a 4-speed to an 8-speed transm ission. GM has publicly claimed a fuel economy improvement of up to 4 percent for its new 6-speed automatic transmissions. 188 The 2008 EPA Staff Technical Report found a 4.5 to 6.5 percent fuel consumption improvement for a 6-speed over a 4-speed automatic transmission. 189

For the final rule, NHTSA estimated that the conversion to a 6-,7- and 8-speed transmission (NAUTO) from a 4 or 5-speed automatic transmission with IATC would have an incremental fuel consumption benefit of 1.4 percent to 3.4 percent, for all vehicle subclasses. The 2008 Martec report, which quot ed high volume, fully learned costs, was relied on to develop the final rule cost estimates. Subcompact, Compact, Midsize, Large Car and Minivan subclasses, which are ty pically considered normal performance passenger cars, are assumed to utilize a 6-speed automatic transmission only (as opposed to 7 or 8 speeds) resulting in an increm ental RPE cost of $323 from Martec 2008. For Performance Subcompact, Performance Comp act, Performance Midsize, Performance Large car and Small, Midsize and Large truc k, where performance and or payload/towing may be a larger factor, NHTSA assumed th at 6-, 7- or 8-speed transmissions are applicable thus the incremental RPE cost range of $323-$638 was established which used the Martec 2008 six speed cost and 8-speed costs for the estimates.

This technology will be available from the start of the rulemaking period. Confidential
manufacturer data indicates the widespread use of 6-speed or greater automatic
transmissions and introductions into the fleet occur primarily at vehi cle redesign cycles. This prompted NHTSA to set the phase-in ra te at 50 percent for MY 2011, but also to consider that the technology can only be applie d at a redesign cycle, as opposed to the refresh cycle application of the NPRM. Th e technology is determined to be at high

188 General Motors, news release, “From Hybrids to Six-Speeds, Direct Injection And More, GM’s 2008 Global Powertrain Lineup Provides More Mile s with Less Fuel” (releas ed Mar. 6, 2007). Available at http://www.gm.com/experience/fuel_economy/news/2 007/adv_engines/2008-powertrain-lineup-082707.jsp (last accessed Sept. 18, 2008).

189 Page 17, “EPA Staff Technical Report: Cost and Effectiveness Estimates of Technologies Used to Reduce Light-duty Vehicle Carbon Dioxide Emissions” Environmental Protection Agency, EPA420-R-08- 008, March 2008.V-112

volume in the 2011 timeframe, and since these are mature and stable technologies, timebased learning factors are applied.

(iii) Dual Clutch Transmissions / Au tomated Manual Transmissions (DCTAM) An automated manual transmission (AMT) is similar in architectur e to a conventional manual transmission, but shifting and launch functions are performed through hydraulic
or electric actuation. There are two basic types of AMTs, single-cl utch and dual-clutch transmission (DCT), both of which were considered in the NPRM. Upon further consideration and in response to manufactur er comments to only include dual-clutch AMTs, single-clutch AMTs are not applie d in the analysis for the final rule.

Single clutch transmissions exhibit a torque interruption when changing gears because the clutch has to be disengaged. In a conventional manual transmission vehicle, the driver has initiated the gear change, and so expects to feel the resulting torque interruption. With an AMT, in contrast, a control system initiates the shift, which is unexpected and can be disconcerti ng to the driver. Comments from Ford in response to the NPRM indicated that the acceptability of this torque interruption among U.S. drivers is poor, although Ford also commented that DCTs do not have the risk of customer acceptance that AMTs do. BorgWarner, a DCT supplier, echoed these comments. DCTs do not display the torque interrupt characte ristic due to their use of two clutch mechanisms which allow for uninterrupted power transmission. To assist with launch of a DCT equipped vehicle, the first gear ratio ca n be deepened to gain back some of the performance advantage an automatic transmissi on possesses due to the torque converter’s torque multiplication factor.

There are two types of DCT systems, wet cl utch and dry clutch, which are used for different types of vehicles. Wet clutch DC Ts offer a higher torque capacity that comes from the use of a hydraulic system that cools th e clutches, but that are less efficient than the dry clutch type due to the losses asso ciated with hydraulic pumping. Additionally, wet DCTs have a higher cost due to the a dditional hydraulic hardware required. Wet clutch DCT systems have been available in the U.S. market on imported products since 2005, and Chrysler has publicly stated that it will have a DCT transmission in its 2010 model year vehicle line-up. 190

Consistent with manufacturers’ confidenti al comments and based on its own analysis, NHTSA determined that dry clutch DCTs ar e applicable to smaller front wheel drive cars, due to their lower vehicle weight a nd torque production, and wet clutch DCTs are more applicable to higher torque applications with higher power re quirements. Therefore lower cost, higher efficiency dry clutch DC Ts are specified for the Subcompact and Compact Car vehicle classes, while all other classes required wet clutch DCTs.

In the NPRM, NHTSA estimated that th e incremental cost for DCTs was $141, independent of vehicle class, which was the midpoint of the NESCCAF estimates and within the range provided c onfidential manufacturer data. CARB commented that

190 Chrysler blog, “Dual-Clutch Transmissions Explained” (released October 3, 2007) available at http://blog.chryslerllc.com/blog.do?p=entry &id=113, last accessed September 18, 2008.V-113

NHTSA had incorrectly cited the cost of AMTs from the NESCCAF study in the NPRM, stating that AMTs had been determined to be cost neutral (zero co st) relative to baseline transmission, as opposed to a $0-$240 cost ju stification. Confiden tial manufacturer data suggest additional DCT costs from $80 to $740, with dry clutch DCT costs being approximately $100 less due to reduced hydrau lic system content. The 2008 Martec study also reported variable costs for AMTs.

In the NPRM, NHTSA cited the NESCCAF study as projecting that AMTs could incrementally reduce fuel consumption by 5 to 8 percent and confid ential manufacturer data projected that AMTs could incrementally reduce fuel consumption by 2 to 5 percent. On the basis of these estimates, NHTSA c oncluded in the NPRM that AMTs could incrementally reduce fuel consumption by 4.5 to 7.5 percent. Conf idential manufacturer data received in response to the NPRM sugge st a benefit of 2 to 12 percent for DCTs over a 6-speed planetary automatic, and one confidential manufacturer estimates a benefit of 1 to 2 percent for a dry clutch DCT over a wet clutch DCT. The 2008 EPA Staff Technical Report also indicates a benefit of 9.5 to 14.5 percent for a DCT (wet or dry was not specified) over a 4-speed plan etary automatic transmission.

For the final rule, NHTSA estimated a 5.5 to 9.5 percent improvement in fuel consumption over a baseline 4/5-speed automatic transmission for a wet clutch DCT,
which was assumed for all vehicle subclasses ex cept Subcompact and Compact Car. This
results in an incremental effectiveness estimate of 2.7 to 4.1 percent over the NAUTO technology. For Subcompact and Compact Cars, which were assumed to use a dry clutch DCT, NHTSA estimated an 8 to 13 percent fuel consumption improvement over a baseline 4/5-speed automatic transmissi on, which equates to a 5.5 to 7.5 percent incremental improvement over the NAUTO technology.

The 2008 Martec report was utilized to devel op the cost estimates for the final rule; it estimated an RPE cost of $450 for a dry clutch DCT, and $600 for a wet clutch DCT,
both relative to a baseline 4/5- speed. In the transmission de cision tree for the final rule, this yielded a dry clutch DCT incremental cost estimate of $68 for the Subcompact and Compact Cars relative to the NAUTO technol ogy. For Midsize, Large Car and Minivan
classes the wet clutch DCT incremental cost over NAUTO is $218, which reflects the lower, 6-speed only cost of the NAUTO t echnology applied to these vehicles. The average incremental cost for wet DCT for th e four Performance classes and the Small, Midsize and Larger truck is $61, which is lowe r than the other vehi cle subclasses due to the higher cost NAUTO technology (up to 8-speeds) that the DCTAM technology supersedes.

NHTSA relied upon confidential manufactur er product plans showing DCT production will be readily available and at high volum e by 2011. Therefore volume-based learning is not applicable, and since th is is a mature and stable t echnology, time-based learning is applied. As production facility conversion or construction may be required to facilitate required capacity, NHTSA limited the produc tion phase-in caps in MY 2011 to 20 percent. As with other transmission tec hnologies, application wa s allowed at redesign only due to the vehicle changes requir ed to adapt a new type transmission.V-114

(iv) Continuously Variab le Transmission (CVT) A continuously variable transmission (CVT) is unique in that it does not use gears to provide ratios for operation. Most CVTs use either a belt or chai n on a system of two pulleys (the less common toroidal CVTs repl ace belts and pulleys with discs and rollers) that progressively vary the ratio, thus permitting an infinite number of effective gear
ratios between a maximum and minimum value, and often a wider range of ratios than
conventional automatic transmissions. This enables even finer optimization of the transmission ratio under different operating conditions and, therefore, some reduction of engine pumping and friction losses. In theor y, the CVT has the abil ity to be the most
fuel-efficient kind of transmission due to the infinite ability to optimize the ratio and operate the engine at its most efficient point. However, this effectiveness is reduced by the significant internal losses from hi gh-pressure, high-flow-rate hydraulic pump, churning, friction loss, and bearing losses requir ed to generate the high forces needed for
traction. 191

Some U.S. car manufacturers have abandoned CVT applications because they failed to deliver fuel economy improvements over au tomatic transmissions. GM abandoned the
use of CVT before 2006. 192 Ford offered a CVT in the Five Hundred and Freestyle from
MYs 2005-2007 and discontinued it thereafter. Ho wever, Chrysler offers CVTs in the Dodge Caliber, the Jeep Compass, and the Jeep Patriot. Nissan was using CVTs in many vehicles, but appears to be re stricting the use of this technology to pa ssenger cars only.

In the NPRM, NHTSA estimated a CVT effectiv eness of approximately 6 percent over a 4-speed automatic, which was above the NESC CAF value but in the range of NAS. For costs, NHTSA concluded in the NPRM that the adjusted costs presented in the 2002 NESCCAF study represent the best available estimates, and thus estimated that CVTs could incrementally reduce fuel consump tion by 3.5 percent when compared to a conventional 5-speed automatic transmission (which cost an incremental $76 - $167), a technology which is considered a baseline tr ansmission option on the final rule decision tree, at an incremental cost of $100 to $139. After reviewing confidential manufacturer data and the Martec report, for the final ru le NHTSA is now estimating the incremental cost of CVTs to be $300 for all vehicle s ubclasses, except for large performance cars, midsize light trucks and large light trucks for which the technology is incompatible.

Confidential manufacturer data in response to the NPRM suggested that the incremental effectiveness estimate from CVTs may be 2 to 8 percent over 4-speed planetary transmissions in simulation (however one commenter reported a zero percent improvement in dynamometer testing) at a cost of $140 to $800. Considering the NPRM conclusion and confidential data togeth er with independent review, NHTSA has

191 “Transmission and Driveline – Major contributors to FUEL efficiency, safety, fun to drive and brand differentiation”, Car Training Institute Symposium, May 6-7, 2008- Plenary Speech, Robert Lee, Vice President, Mircea Gradu, Director Transmission and Driveline, Chrysl er LLC, USA. Available from the Car Training Institute, for contact information see http://www.car-traininginstitute.com/cti_en/html/kontakt.h tml (last accessed Nov. 9, 2008).

192 See http://car-reviews.automobile.com/news/ge neral-motors-to-kill-continually-variabletransmission/166/ (last accessed Oct. 23, 2008).V-115

estimated the fuel consumption effectiveness for CVTs at 2.2 to 4.5 percent over a 4/5- speed automatic transmission, which translates into a 0.7 to 2.0 incr emental effectiveness improvement over the IATC technology. NHTSA estimated the CVT incremental cost to be $300 for the final rule, noting that the NP RM costs were incremental to a 5-speed technology that is no longer re presented in the decision tree , hence the higher final rule

cost. 193

CVTs are currently available, but due to thei r limited torque-carrying capability, they are not applied to Performance Large cars and Midsize and Large trucks. There is limited production capability for CVTs, so the phase-i n cap for MY 2011 is limited to 5 percent to account for new plants and tooling to be pr epared. CVTs can be introduced at product redesign intervals only based on confidential manufacturer data and consistent with the NPRM approach (since it requires vehicle at tribute prove-out, test and certification prior to introduction). Confidential manufacturer da ta indicates that CVTs will be at high volumes by 2011, and this is a mature and stable technology, therefore NHTSA applied time-based learning factors.

(v) 6-Speed Manual Transmissions (6MAN) Manual transmissions are entirely dependent upon driver input to change gear ratio: the driver selects when to perform the shift and which gear ratio to select. This is the most efficient transfer of energy of all transmissi on layouts, because it has the lowest internal gear losses, with a minimal hydraulic syst em, and the driver provides the energy to actuate the clutch. From a systems vi ewpoint, however, vehicles with manual
transmissions have the drawback that the driv er may not always select the optimum gear ratio for fuel economy. Nonetheless, increa sing 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 more often. Typically, this is achieved through adding overdrive ratios to reduce engine speed at cr uising velocities (which saves fuel through reduced pumping losses) and pushing the torq ue required of the engine towards the optimum level. However, if the gear rati o steps are not properly designed, this may require the driver to change gears more of ten in city driving resulting in customer dissatisfaction. Additionally, if gear ratios are selected to achieve improved launch performance instead of to improve fuel ec onomy, then no fuel saving effectiveness is
realized.

NHTSA recognizes that while the manual transmissi on is very efficient, its effect on fuel consumption relies heavily upon driver input. In driving environments where little shifting is required, the manual transmission is the most efficient because it has the
lowest internal losses of all transmissions . However, the manual transmission may have lower fuel efficiency on a drive cycle wh en drivers shift at non-optimum points.

In the NPRM, NHTSA estimated that a 6-sp eed manual transmission could incrementally reduce fuel consumption by 0.5 percent when compared to a 5-speed manual transmission, at an incremental cost of $107. Confidential manufactur er data received in

193 Since the decision trees are configured differently , the net cost to CVT in the NPRM included 5-speed automatic transmission technology costs that are not applied in the final rule.V-116

response to the NPRM suggests that manual transmissions could incrementally reduce fuel consumption by 0 to 1 percent over a base 5-speed manual transmission at an incremental cost of $40 to $900. Most c onfidential comments suggested that the incremental cost was within the lower quart ile of the full range, thus $225 (the lower quartile upper-bound) was multiplied by the 1.5 RP E markup factor for a total of $338. Therefore, the final rule states that the in cremental fuel consumption effectiveness for a 6-speed manual transmission over a 5-speed ma nual transmission is 0.5 percent at a RPE cost of $338.

This technology is applicable to all vehicle classes consider ed and can be introduced at product redesign intervals, consistent with th e NPRM and other final rule transmission technologies. Six-speed manuals are alrea dy in production at stable and mature high volumes so time-based learning is applied wi th a 33 percent phase-in rate for MY 2011.

(d) Hybrid and Electrification/Accessory Technologies (i) Overview A hybrid describes a vehicle that combines two or more sources of energy, where one is a consumable energy source (like gasoline) and one is rechargeable (during operation, or by another energy source). Hybrids redu ce fuel consumption through three major mechanisms: (1) by turning off the engine wh en it is not needed, such as when the vehicle is coasting or when stopped; (2) by re capturing lost braking energy and storing it for later use; and by (3) optimizing the opera tion of the internal combustion engine to operate at or near its most efficient point more of the time. A fourth mechanism to reduce fuel consumption, available only to pl ug-in hybrids, is by substituting the fuel energy with energy from another so urce, such as the electric grid.

Engine start/stop is the most basic of hybrid functions, and as the name suggests, the engine is shut off when the vehicle is not moving or when it is coasting, and restarted
when needed. This saves the fuel that woul d normally be utilized to spin the engine when it is not needed. Regenerative brak ing is another hybrid function which allows
some of the vehicle’s kinetic energy to be recovered and la ter reused, as opposed to being
wasted as heat in the brakes. The reused energy displaces some of the fuel that would normally be used to drive the vehicle, and thus results in reduced fuel consumption. Operating the engine at its most efficient operating region more of the time is made possible by adding electric motor power to the engine’s power so that the engine has a degree of independence from the power required to drive the vehicle. Fuel consumption is reduced by more efficient engine opera tion, the degree of which depends heavily on the amount of power the electric motor can prov ide. Hybrid vehicles with large electric motors and battery packs can take this to an extreme and drive th e wheels with electric power only and the engine consuming no fuel. Plug-in hybrid vehicles can substitute fuel energy with electrical energy, furt her reducing the fuel consumption. 194

194 Substituting fuel energy with electrical energy ma y not actually save total overall energy used, when considering the ineffici encies of creating the electric ity at a power plant and storing it in a battery pack, but it does enable use of other primary energy sources, an d reduces the vehicle’s fuel consumption. Plug-in hybrids are also receiving increasing attention because of their ability to use “clean energy” from the electric grid, such as that solar or wind, whic h can reduce the overall greenhouse gas output.V-117

Hybrid vehicles utilize some combination of the above mechanisms to reduce fuel consumption. The effectiveness of a hybri d, and generally the complexity and cost, depends on the utilization of the above m echanisms and how aggressively they are pursued.

In addition to the purely hybrid technol ogies, which decrease the proportion of propulsion energy coming from the fuel by increasing the proportion of that energy coming from electricity, there are other steps th at can be taken to improve the efficiency of auxiliary functions ( e.g. , power-assisted steering or air-conditioning) which also reduce fuel consumption. These steps, t ogether with the hybri d technologies, are collectively referred to as “vehicle electrificat ion” because they generally use electricity instead of engine power. Th ree “electrification” technologi es are considered in this analysis along with the hybrid technologies: electrical pow er steering (EPS), improved accessories (IACC), and high voltage or im proved efficiency alternator (HVIA).

(ii) Hybrid System Sizing a nd Cost Estimating Methodology Estimates of cost and effectiveness for hybrid and related electrical technologies have been adjusted from those described in the NPRM to address commenters’ concerns that NHTSA considered technologies not lik ely to be adopted by automakers ( e.g. , 42V electrical systems) or did not scale the cost s for likely technologies across the range of
vehicle subclasses considered. To address these concerns, the por tfolio of vehicle electrification technolog ies has been refined based on comme nter data as described below in the individual hybrid technol ogies sections. Ricardo and NHTSA have also developed a “ground-up” hybrid technology cost esti mating methodology and, where possible,
validated it to confidential manufacturer data. The hybrid technology cost method
accounts for variation in com ponent sizing across both the hyb rid type and the vehicle platform. The method utilizes four pieces of data: (1) key component sizes for a midsize car by hybrid system type; (2) normalized costs for each key component; (3) component scaling factors that are app lied to each vehicle subclass by hybrid system type; and (4)
vehicle characteristics for the subclasses wh ich are used as the basis for the scaling
factors.

Component sizes were estimated for a mids ize car using publicly available vehicle specification data and commenter data for each type of hybrid system as shown in Table

V-10.V-118

Table V-10. Component Sizes by Hybrid Type for a Midsize Car

Component MHEV ISG PSHEV 2MHEV PHEV

Primary Motor power, continuous (kW) 3 11 45 45 45 Secondary Motor power, continuous (kW) na na 30 45 30 Primary Inverter power, continuous (kW) 3 11 45 45 45 Secondary Inverter power, continuous (kW) na na 30 45 30 Controls complexity (relative to strong hybrid) 25% 50% 100% 100% 100% NiMH Battery Pack capacity (kW-hr) na 1 2 2 na Li-Ion Battery Pack capacity (kW-hr) na na na na 15 DC/DC Converter power (kW) 0.7 3 3 3 3 High Voltage Wiring (relative to strong hybrid) na 50% 100% 100% 100% Supplemental heating Yes Yes Yes Yes Yes Mechanical Transmission (relative to baseline vehicle) 100% 100% 50% 100% 25%

Electric AC No No Yes Yes Yes

Blended Brakes No No Yes Yes Yes Charger power, continuous (kW) na na na na 3 Hybrid Type

In developing Table V-10, NHTSA made several assumptions: 1) Hybrid controls hardware varies with the level of functionality offered by the hybrid technology. Assumed hybrid cont rols complexity for a 12V micro hybrid (MHEV) was 25 percent of a st rong hybrid controls system and the complexity for an Integrated Starter Generator (ISG) was 50 percent. These ratios were estimates based on the directional need for increased functionality as system complexity increases. 2) In the time frame considered, Li-ion ba ttery packs will have limited market penetration, with a majority of hybrid vehicles using NiMH batteries. One
estimate from Anderman indicates that Li-ion market penetration will achieve 35 percent by 2015. 195 For the purposes of this analysis, it was assumed that mild and strong hybrids will use NiMH batteries and plug-in hybrids will use
Li-ion batteries. 3) The plug-in hybrid battery pack was si zed for a mid-sized car by assuming:
the vehicle has a 20 mile all electric range and consumes an average of 300 W-hr per mile; the battery pack can be discharged down to 50 percent depth of discharge; and the capacity of a new batte ry pack is 20 percen t greater than at end of life ( i.e. , range on a new battery pack is 24 miles). 4) All hybrid systems included a DC/DC converter which was sized to
accommodate vehicle electrical loads appropriate for increased vehicle
electrification in the time frame considered. 5) High voltage wiring scaled with hybrid vehicle functionality and could be represented as a fraction of strong hybr id wiring. These ratios were estimates
based on the directional need for increased functionality as system complexity
increases. 6) All hybrid systems included a supplementa l heater to provide vehicle heating when the engine is stopped, however, only stronger hybrids included electric air conditioning to enable engine stop/s tart when vehicle air conditioning was requested by the operator.

195 Anderman, Advanced Automotive Battery Conference, May 2008. Pr oceedings available for purchase at http://www.advancedautobat. com/Proceedings/index.html (l ast accessed October 17, 2008).V-119

In the hybrid technology cost methodology deve loped for cost-scaling purposes, several strong hybrid systems replaced a conventiona l transmission with a hybrid-specific transmission, resulting in a co st offset for the removal of a portion of the clutches and gear sets within the transmission. The tran smission cost in Table V-11 below expresses hybrid transmission costs as a percentage of traditional automatic transmission cost, as described in the 2008 Martec Report, at $850. The method assumed that the mechanical aspect of a power-split transmission with a reduced number of gear sets and clutches resulted in a cost savings of 50 percent of a conventional transmission with torque converter. For a 2-mode hybrid, the mechanical aspects of the transmission are similar in complexity to a conventional transmission with a torque converter, thus no mechanical cost savings was appropriate. The pl ug-in hybrid assumed a highly simplified transmission for electric motor drive, thus 25 percent of the base vehicle transmission cost was applied.

Estimates for the cost basis of each key component are shown in Table V-11 below alongwith the sources of those estimates. The cost basis estimates assume fully learned, highvolume (greater than 1.2 million units per annum) production. The costs shown are variable costs that are not RPE adjusted.V-120

Table V-11. Component Cost Basis at High Volumes and Data Sources

Component Cost

Basis Data Source

Primary Motor ($/kW) 15 $ Secondary Motor ($/kW) 15 $ Primary Inverter ($/kW) 10 $ Secondary Inverter ($/kW) 10 $

Controls 100 $

NiMH Battery Pack ($/kW-hr.) 50 $ Attorneys General/Anderman comments (NHTSA-2008-089-0199.5)

Li-Ion Battery Pack ($/kW-hr.) 600 $ Anderman, AABC 2008 ($900/kW-hr @

2000 units/ y r learned and rounded )
DC/DC Converter 100 $ Confidential business information High Voltage Wiring 250 $ Supplemental heating 84 $

Mechanical Transmission 850 $ Martec 2008 (to 4-spd. Auto.)

Electric AC 450 $ Confidential business information

Blended Brakes 400 $ Martec 2008 Charger 100 $ Confidential business information Automatic Transmission pump 75 $ Martec 2008 Martec 2008

Martec 2008 Confidential business information

Component scaling factors were determin ed based on vehicle characteristics for each type of hybrid system as shown in Table V-12 below.V-121

Table V-12. Component Scaling Factors appl ied to Vehicle Class for each Hybrid System Type

Component MHEV ISG PSHEV 2MHEV PHEV

Primary Motor Engine displacement Curb weight Engine

power

Secondary Motor na na Vehicle

mass 2
Primary Inverter Secondary Inverter na na
Controls NiMH Battery Pack na na

Li-Ion Battery Pack na na na na Vehicle

mass DC/DC Converter High Voltage Wiring na Supplemental heating

Mechanical Transmission
Electric AC na na

Blended Brakes na na

Charger na na na na Same for all

vehicle

classes

(1) For all vehicle classes except for performance classes which use Engine Torque

(2) Vehicle mass used as surrogate for vehicle road load

(3) Vehicle mass used as surrogate for vehicle electrical load Hybrid Type

Engine displacement Curb weight 1

Vehicle mass 3 Vehicle footprint Primary motor power Secondary motor power Complexity

Vehicle mass

Same for all vehicle classes Vehicle footprint

Vehicle footprint
Same for all vehicle classes

NHTSA’s CAFE database was used to define the average vehicle characteristics for each vehicle subclass as shown in Table V-13 below, and these attributes were used as the basis of the scaling factors.V-122

Table V-13. Key Vehicle Characte ristics For Each Vehicle Class



### Vehicle Subclass Curb Weight

(lbs) Footprint (ft2) Engine Disp. (L) Power (hp) Torque (ft-lb)

Subcompact Car 2795 41 1.9 134 133 Compact Car 3359 44 2.2 166 167

Midsize Car 3725 47 2.9 205 206 Large Car 4110 50 3.4 258 248 Performance Subcompact Car 3054 40 2.7 260 260 Performance Compact Car 3516 44 3.0 269 260

Performance Midsize Car 3822 47 3.9 337 318 Performance Large Car 4189 51 4.8 394 388

Minivan 4090 50 3.3 247 242

Small Truck 3413 45 2.6 178 185

Medium Truck 4260 50 3.6 250 256 Large Truck 5366 63 5.0 323 352

Table V-14 shows the costs for the differe nt types of hybrid systems on a midsize vehicle. The individual component costs were scaled from the normalized costs shown in Table V-11 according to the component size sh own in Table V-10 and adjusted to a low volume cost by backing out vol ume-based learning reductions. 196 These component costs were summed to get the total low volum e cost for each hybrid type, and a 1.5 RPE adjustment was applied. The ISG t echnology replaces the MHEV technology on the Electrification/Accessory technology decision tree, therefore the MHEV technology costs
must be subtracted to reflect true costs ($2,898 - $707 = $2,191 in this example).

Wherever possible, the results of the hybrid technology cost method were compared with values as previously described in the NP RM and the results ge nerally matched prior estimates. Additionally, th e results from the hybrid technology cost method were validated with public literature and confiden tial manufactures test data as allowed. Elements of the 2008 Martec report identified cost data and a deta iled bill of materials for several comparable hybrid technologies (Mic ro-hybrid systems and Full Hybrid systems), and the hybrid technology cost model agreed well with this data. The scalable bill of material based methodology described above wa s determined to offer the best solution for estimating component sizes and costs across a range of hybrid systems and vehicle platforms and the validation of these cost out puts with other data sources suggests that this approach is a reasonable approach.

196 High volume costs are multiplied by a factor of 1.56, which represents two cycles of 20 percent reverse learning, to determine th e appropriate low volume, or unlearned costs.V-123

Table V-14. Hybrid System - Mi dsize Vehicle Low Volume Costs

(iii) Electrical Power Steering (EPS) Electrical Power Steering (E PS) is advantageous over conventional hydraulic powerassisted steering in that it only draws power when the vehicl e is being steered, which is typically a small percentage of the time a ve hicle is operating. In fact, on the EPA test cycle no steering is done, so the CAFE fuel consumption effectiveness comes about by eliminating the losses from driving the hydr aulic steering pump at engine speed. EPS systems use either an electric motor drivi ng a hydraulic pump (this is a subset of EPS systems known as electro-hydraulic power steering) or an electr ic motor directly assisting in turning the steering column. EPS is seen as an enabler for all vehicle hybridization technologies, since it provides power steering when the engine is off. This was a primary consideration in placing EPS at the top of the Electrificat ion/Accessory decision tree.

In the NPRM, NHTSA estimated the fuel cons umption effectiveness for EPS at 1.5 to 2 percent at an incremental cost of $118 to $197, believing confidential manufacturer data most accurate. In response to the NPRM Sierra Research suggested EPS and high MHEV ISG* PSHEV 2MHEV PHEV

Primary Motor [Example: MHEV = 3KW * 15$/KW * 1.56 (vol uplift)] 70 $ 263 $ 1,053 $ 1,053 $ 1,755 $

Secondary Motor - $ - $ 702 $ 1,053 $ 702 $ Primary Inverter 47 $ 176 $ 702 $ 702 $ 1,170 $ Secondary Inverter - $ - $ 468 $ 702 $ 468 $

Controls 39 $ 78 $ 156 $ 156 $ 156 $ NiMH Battery Pack - $ 546 $ 1,092 $ 1,092 $ - $ Li-Ion Battery Pack - $ - $ - $ - $ 14,040 $

DC/DC Converter 109 $ 468 $ 468 $ 468 $ 468 $ High Voltage Wiring - $ 195 $ 390 $ 390 $ 390 $ Supplemental heating 131 $ 131 $ 131 $ 131 $ 131 $

Mechanical Transmission - $ - $ (663) $ - $ (995) $

Electric AC - $ - $ 702 $ 702 $ 702 $

Blended Brakes - $ - $ 624 $ 624 $ 624 $ Charger - $ - $ - $ - $ 468 $ Automatic transmission pump 75 $ 75 $ - $ - $ - $
Total Hybrid System Cost @ Low Volume 471 $ 1,932 $ 5,825 $ 7,073 $ 20,080 $

RPE (1.5) System Cost @ Low Volume 707 $ 2,898 $ 8,738 $ 10,610 $ 30,119 $ Component Hybrid Type Low Volume (Unlearned) Costs

* ISG replaces the MHEV technology on the Accessory/Electrification Decision TreeV-124

efficiency alternators combined is worth 1 to 1.8 percent on the CAFE test cycle, 197 and
confidential manufacturer data indicated a 0.7 to 2.9 percent fuel consumption reduction. The cost range from confidential manufactur er data was $70 to $300. Sierra estimated EPS for cars at $82 and $150 for trucks. 198 A market study by Frost & Sullivan indicated the cost of an EPS system at roughly $65 more than a conventi onal hydraulic (HPS)
system. 199 Because there is a wide range in the effectiveness for EPS depending on the vehicle size, NHTSA has increased the range from the NPRM to incorporate the lower ranges suggested by most manufacturers and estimates the fuel consumption effectiveness for EPS at 1 to 2 percent for th e purpose of the final rule. The incremental costs are also estimated on range below the Si erra value for cars but above the Frost & Sullivan estimate at a piece cost range of $70 to $80 and included a 1.5 RPE uplift to $105 to $120 for the final rule.

EPS is currently in volume production in small to mid-sized vehicles with a standard 12V electrical system; however, heavier vehicles may require a higher voltage system, which adds cost and complexity. The Chevy Tahoe Hybrid, for example, uses a higher voltage EPS system. For purposes of the final rule , NHTSA has applied EPS to all vehicle subclasses except for Large trucks.

In the NPRM, NHTSA assumed a 25 percent ph ase in rate of EPS technologies. For the purposes of the final rule, EPS phase-in caps were limited to 10 percent in MY 2011 to
address confidential manufacturer concerns over lead time. In the NPRM, NHTSA assumed a volume-based learning effect for EPS. For the final rule, however, NHTSA applied time-based learning for EPS since NHTSA’s analysis indicated that this technology would be in high-volume use at the beginning of its fi rst year of availability. NHTSA also assumed in the NPRM that EPS could be applied during refresh model years, which was consistent with informa tion provided in confid ential product plans, therefore for the purpose of the final rule, NHTSA again applied EPS at refresh timing.

(iv) Improved Accessories (IACC) Improved accessories (IACC) was defined in th e NPRM as improvements in accessories such as the alternator, coolant and oil pumps that are traditionally driven by the engine. Improving the efficiency or outright electrif ication of these accessories would provide opportunity to reduce the accessory loads on the engine. However, as the oil pump provides lubrication to the e ngine’s sliding surfaces such as bearings pistons, and camshafts and oil flow is always required when the engine is spinning, and it is only supplied when the engine is spinning, there is no efficiency to be gained by electrifying the oil pump. 200

197 Docket No. NHTSA-2008-0089-0179.1, Attachment 2, at 53.

198 Docket No. NHTSA-2008-0089-0179.1, Attachment 2, at 59.

199 Cost for EPS quoted at 48 Euros, at $1.35 per Euro exchange rate (Oct. 7, 2008) equates to $65, from Frost & Sullivan, Feb. 9, 2006 “Japanese Steering System Market Moves Into High Gear,” http://www.theautochannel.com/news/2006/02/09/ 210036.html (last acce ssed Nov. 2, 2008).

200 Oil pump electrification comes with an additional potential technical and financial risk (to warranty and consumer), in that significant engine damage can occur should the system fail to provide engine lubrication, even on a momentary basis.V-125

Electrical air conditioning (EAC ) could reduce fuel consumption by allowing the engine
to be shut off when it is not needed to driv e the vehicle. For this reason EAC is often used on hybrid vehicles. In highway driving, ho wever, there is little opportunity to shut the engine off; furthermore EAC is less effi cient when the engine is running because it requires mechanical energy from the engine to be converted to electr ical energy and then back again to mechanical. Since air condi tioning is not required on the EPA city or highway test cycles, there is no CAFE fuel consumption effectiveness from EAC. Therefore, EAC does not improve accessory efficiency apart from the hybrid technologies. For the purposes of the final rule, IACC refers strictly to improved engine cooling, since electrical lubric ation and air conditioning are no t effective stand-alone fuel saving technologies and improve d alternator is considered as a separate technology given its importance to vehicle electrification.

Improved engine cooling, or intelligent c ooling, can save fuel through two mechanisms: by reducing engine friction as the engine wa rms up faster; and by ope rating an electric coolant pump at a lower speed than the engine would ( i.e. , independent of engine speed). Intelligent cooling can be applied to vehicles that do not typically carry heavy payloads. Larger vehicles with towing capacity present a challenge for electrical intelligent cooling systems, as these vehicles have high cooli ng fan loads. Therefore NHTSA did not apply IACC to the Large Truck and SUV class.

In the NPRM, NHTSA estimated the fuel consumption effectiveness for improved accessories at 1 to 2 percent at an incr emental cost of $124 to $166 based on the 2002 NAS Report and confidential manufacturer data. Confidential manufacturer data received in response to the NPRM and Sierra Research both suggested a range for fuel consumption effectiveness from 0.5 to 2 pe rcent. A comment from MEMA suggested that improved thermal control of the engine could produce between 4 and 8 percent fuel economy improvement; 201 however, NHTSA’s independent re view of intelligent cooling suggests this estimate is high and concurs w ith the estimates from NAS. Independent
review found the cost for IACC at low volumes , assuming the base vehicle already has an electric fan, to be $180 to $220. These costs were adjusted to account for volume-based learning and then marked up to account for the 1.5 RPE factor. For the purposes of the final rule, NHTSA retained the fuel consum ption effectiveness at 1 to 2 percent and estimated the incremental costs to be $173 to $211.

MEMA also suggested that NHTSA consid er solar glass tech nology to reduce cabin thermal loading; however, air conditioning techno logies were not considered as part of this technology.

In the NPRM, NHTSA proposed a 25 percent ph ase-in cap for Improved Accessories. To
address manufacturer concerns over lead time in the early years, the IACC phase-in cap was limited to 10 percent for MY 2011for the final rule. In the NPRM, NHTSA assumed for improved accessories a volume-based learning curve. For the final rule, however, NHTSA applied time-based learning for IACC since NHTSA’s analysis indicated that this technology would be in high-volume use at the beginning of its first year of

201 Docket No. NHTSA-2008-0089-0193.1.V-126

availability. NHTSA assumed in the NPRM that improved accessories could be applied during any model year. For the purpose of the final rule, NHTSA applied intelligent cooling at refresh model years due to the significant changes re quired to the vehicle cooling system that necessita te recertification testing.

(v) 12V Micro Hybrid (MHEV) 12V Micro-Hybrid (MHEV) systems are the most basic of hybrid systems and offer mainly idle-stop capability. Their low cost and easy adaptability to existing powertrains and platforms can make them attractive for some applications. The conventional beltdriven alternator is replaced with a belt-d riven, enhanced power st arter-alternator and a redesigned front-end accessory drive system that facilitates bi-directional torque application. Also, during id le-stop, some functions su ch as power steering and automatic transmission hydraulic pressure are lost with conventiona l arrangements; so electric power steering and an auxiliary transmission pump are needed. These components are similar to those that would be used in other hybrid designs. Also included in this technology is the Smart Starte r Motor. This system is comprised of an enhanced starter motor, along with some electronic control that monitors the accelerator, brake, clutch positions, and the batte ry voltage as well as low-noise gears to provide fast and quiet engine starts. Despite its exte nded capabilities, the starter is compact and thus relatively easy to integrate in the vehicle.

12V micro hybrid was added to the technology list to address con cerns from CARB and Delphi that the hybrid classifications used in the NPRM did not adequately represent these technologies. 202

The effectiveness estimates by NHTSA for this technology are based on confidential
manufacturer data and inde pendent source data. For th e vehicles equipped with (baseline) inline 4, those with smaller displa cements, the effectiveness is between 1 and 2.9 percent, and for those equipped with V-6 or V-8, the effectiveness is between 3.4 and 4 percent. The 1 to 2.9 percent incremental fuel consumption savings applies to the SubCompact Car, Performance Sub-Compact Car, Compact Car, Midsized Car, and Small
Truck/SUV variants. The 3.4 to 4 percent incremental fuel consumption applies to the remaining classes with the exception of La rge Truck/SUV where MHEV is not applied due to payload and towing re quirements for this class.

Confidential manufacturer comments submitte d in response to the NPRM indicated a $200 to $1000 cost for the MHEV. The 12V mi cro-hybrid does not have a high voltage battery, and thus does not have a high-voltage wire cost. The 12V micro-hybrid system for the midsize vehicle has a 3kW electric motor. This agrees well with two commercially available systems used on smaller engines. 203 The value used for the DC/DC converter represents the cost for a 12V power conditioning circuit to allow uninterrupted power to the radio and a lim ited number of other accessories when the

202 Docket Nos. NHTSA-2008-0089-0173 and -0144.1, respectively.

203 Citroen uses a 2kW system for a 1.4L diesel engine, and Valeo has a 1.6kW system applicable for engines up to 2L in displacement. The midsize vehicl e class has an average engine size of 2.9L, and thus a 3kW starter is appropriate.V-127

engine starter is engaged. The sizing for the rest of the components is shown in Table V9.

The MHEV technology, which will be availabl e from the 2011 model year, is projected to be in high volume use at the beginning of its first year of availability according to NHTSA’s analysis, therefore vol ume based learning reductions (two cycles at 20 percent) were applied to “learn” the hybrid method costs and time based learning factors were applied throughout the remaining years. For the final rule, NHTSA established incremental costs ranging from $372 to $549 with the highest cost applying to the Performance Large Car class.

The 12V micro hybrid technology is applicable across all the ve hicle segments except for the Large Truck/SUV class. Although this t echnology was not specifically stated in the NPRM, a phase-in cap of 3 percent for MY 2011 was assumed for hybrid technologies. For the final rule, this figure was retained since it is generally supportable within the industry as expressed at the SAE HEV Symposium in San Diego in Feb 2008.

The NPRM proposed that all of the hybrid t echnologies could be introduced during the redesign model year only. This view is consis tent with manufacturer’s views, therefore, for this rule making, NHTSA has assumed that 12V micro hybrids can only be introduced at the redesign model years.

(vi) High Voltage / Improved Alternator (HVIA) In the NPRM, a 42V accessory technology was identified in the decision tree for Other Technologies. Several confid ential manufacturer comments received by NHTSA related to 42V technology, and indicated that the effectiveness of 42V system were not realized
when electrical conversion efficiencies were considered, and the cost of transitioning the industry from a 12V to 42V system made the technology unreasonable for deployment in the emerging technology time frame. As a re sult of these comments, NHTSA revised the technology from 42V technol ogy to High Voltage / Impr oved Alternator (HVIA).

The “High Voltage/Improved Efficiency A lternator” technology block represents technologies associated with in creased alternator efficienc y. As most alternators in production vehicles today are optimized for cost and the process for increasing the efficiency of an alternator is well understood by the industry, this technology is applicable to all vehicle subclasses except Midsize and Large Truck and SUV where it is not considered applicable due to the high utility of these classes.

The NPRM identified fuel economy effectiveness that were based on 42V accessory systems, and are not directly applicable for this current technology definition.
Confidential manufacturer data indicates that a midsized car with an improved efficiency alternator provided 0.2 to 0.9 percent fuel consumption effectiveness over the CAFE drive cycles, and a pickup truck provided 0.6 percent fuel consumption effectiveness over the same cycles. As this technology can be applied over a range of vehicles, NHTSA believes the fuel consumption effectiveness fo r larger vehicles will be biased downward.V-128

For purposes of this final rule, NHTSA estimat es the fuel consumption effectiveness for High Voltage/Improved Efficiency Altern ator” technology at 0.2 to 0.9 percent.

The NPRM identified several sources for hi gh voltage / improved efficiency alternators incremental costs, but focuse d this technology on 42V syst ems, thus making some of these references not representative of th e current technology description. The NPRM “Engine accessory improvement” technol ogy discussion, however, did quote the NESCCAF study that indicated a $56 cost for a high efficiency generator. An independent confidential study estimated that the incremental cost increase for a high efficiency generator at high volume was si milar to the NESCCAF quoted cost, thus NHTSA concludes that the NESCCAF study cost of $56 is still a representative cost for this technology. At a 1.5 RPE valu e, this cost equates to $84.

As the definition of the technology has been revised from the NPRM, phase-in rates identified in the NPRM are not applicable . NHTSA believes the High voltage / Improved Efficiency Alternator technology represen ts an adjustment to the alternator manufacturing industry infrastruc ture, so for purposes of this final rule, phase-in caps for this technology were estimated at 10 percent for MY 2011.

Also, as the definition of the technology has been revised from the NPRM, learning curve assumptions from the NPRM are not applicab le. The high voltage / improved alternator technology costs were based on high volume es timates, thus, for purposes of the final rule, NHTSA assumed time-based learning (3 percent YOY) for High Voltage Systems / Improved Alternator technology. For purposes of the final rule, NHTSA assumed the technology can be introdu ced during refresh or redesign model changes only.

(vii) Integrated Starter Generator (ISG) The next hybrid technology that is considered is the Integr ated Starter Generator (ISG) technology. There are 2 types of integrated starter generator h ybrids that are considered: the belt mounted type and the crank mounted type.

A Belt Mounted Integrated Starter Generato r (BISG) system is similar to a microhybrid system, except that here it is define d as a system with a 110 to 144V battery pack which thus can perform some regene rative braking, whereas the 12V micro-hybrid system cannot. The larger electric machin e and battery enables additional hybrid functions of regenerative braking and a ve ry limited degree of operating the engine independently of vehicle load. While having a larger electric mach ine and more battery capacity than a MHEV, this system has a sm aller electric machin e than stronger hybrid systems because of the limited torque capacity of the belt driven design.

BISG systems replace the conventional belt -driven alternator with a belt-driven, enhanced power starter-alternator and a rede signed front-end accessory drive system that facilitates bi-directional torque application utilizing a common electric machine. Also, during idle-stop, some functions such as power steering and automatic transmission hydraulic pressure are lost w ith conventional arrangements; so electric power steeringV-129

and an auxiliary transmission pump need to be added. These components are similar to those that would be used in other hybrid designs.

A Crank Mounted Integrated Starter Genera tor (CISG) hybrid system, also called an Integrated Motor Assist (IMA) system, utilizes a thin axia l electric motor (100-144V) bolted to the engine’s crankshaft. The electr ic machine acts as both a motor for helping to launch the vehicle and a ge nerator for recovering energy wh ile slowing down. It also acts as the starter for the engine and is a highe r efficiency generator. An example of this type of a system is found in the Honda Ci vic Hybrid. For purposes of the final rule, NHTSA assumed the electric machine is rigi dly fixed to the engi ne crankshaft, thus making electric-only drive not practical. 204

The fuel consumption effectiveness of the IS G systems are greater than those of microhybrids, because they are able to perform the additional hybrid function of regenerative braking and able to utilize the engine more efficiently because some transient power demands from the driver can be separated fr om the engine operation. Their transient performance can be better as well, because th e larger electric machin e can provide torque boost. The ISG systems are more expensive th an the micro hybrids, but have lower cost than the strong hybrids described below because the electrical component sizes (batteries, electric machines, power electr onics, etc.) are sized in betw een the micro-h ybrid and the strong hybrid components. The engineering effort required to adapt conventional powertrains to these configura tions is also in between that required for micro-hybrid and strong hybrid configurations. Packaging is a greater concern due to the fact that the engine-motor-transmission assembly is physic ally longer, and the battery pack, high voltage cabling and power electronics are larger.

The hybrid decision tree was modified to address several manufacturer comments and comments from CARB and Delphi asking for more appropriate separation of hybrid technology classifications ( i.e. , 12V versus higher voltage In tegrated Starter Generators, etc.). The inclusion of the ISG technology in the final ru le is in response to these comments and those from subject matter experts.

The NPRM had proposed a fuel consumption savings of between 5 and 10 percent for ISG systems, and between 3.5 and 8.5 percent for the Honda IMA system, both of which fall in the ISG category described above. Confidential manufacturer comments submitted in response to the NPRM indicated an incr emental 3.8 to 7.4 percent fuel consumption effectiveness and a $1,500 to $2,400 cost as co mpared to the baseline vehicle.

The incremental fuel consumption savings for the Compact Car variant for ISG over a 12V Micro-hybrid with start/s top was calculated using publis hed data and confidential manufacturer data, while published Honda Civi c Hybrid data was used to calculate the fuel consumption gains due to the hybrid syst em. For the final rule, gains for the other

204 A clutch between the engine and the electric motor would enable pure electric drive, but the Porsche Cayenne is the only example of such a system that is planned in the rulemaking time frame. Because of limited expected volumes of this type of system, and in the interest of reducing complexity, that variant is
not included here.V-130

technologies also included on th is vehicle were subtracted out to give an incremental effectiveness of 5.7 to 6.5 percent for ISG. Data for these individual gains was taken
from confidential manufacturer data. The 5.7 to 6.5 percent incremental fuel consumption savings was carried over from the Compact Car to all other vehicle subclasses. A 2 percent incremental effectiv eness was subtracted from the Performance subclasses to allow for the improved baseline performance

The NPRM proposed a cost of $1,636 to $2,274 for these systems. For the final rule, NHTSA determined the cost for the ISG system using system sizing data for different available ISG hybrids. The 2006 Honda Civi c has a Crank Mounted ISG and uses a 0.87 kW-hr battery pack. In light of the potentia l growth of vehicle el ectrification, a 1 kW-hr pack size was chosen for both the belt a nd crank mounted ISG systems. The crank mounted ISG was sized as 11kW continuous (15k W peak). This is an average of the 10kW system on the 2003 Honda Civic and th e 12kW system on the 2005 Honda Accord. The 2006 Civic has a 15kW system. The belt m ounted ISG has a slightly smaller electric machine (7.5kW continuous and 10kW peak) due to power transmission limitations of
the belt.

For the final rule, the hybrid technology co st method projected costs ranging from $2,475 to $3,290 for the Sub-Compact car class through the Midsize Truck classes as compared
to the conventional baseline vehicle and the incremental costs of $1,713 to $2,457 were calculated by backing out the prior hybrid technology costs. The ISG technology is projected to be in low volume use at the beginning of the rulemaking period therefore
low volume costs are used and volume- based learning fact ors are applied.

Integrated starter generator sy stems are applicable to all ve hicle subclasses except Large Truck. In the NPRM, a phase-in cap of 3 pe rcent was assumed for both the “ISG with idle off” and “IMA” technologies. For the final rule, NHTSA has retained the phase-in cap of 3 percent. These values are generally supportable within the industry as expressed at the SAE HEV Symposium in San Diego in February 2008.

The NPRM proposed that all of the hybrid t echnologies could be introduced during the redesign model year only. This view is cons istent with manufactur er’s views as well, because all of the hybrid technologies unde r consideration require redesign of the powertrain (ranging from engine accessory drive to transmission redesign) and vehicle redesign to package the hybrid components (f rom high voltage cabling to the addition of large battery packs). Given this, for purposes of the final rule, they can only be introduced in redesign model years.

(viii) Power Split Hybrid The Power Split hybrid (PSHEV) is described as a full or a strong hybrid since it has the ability to move the vehicle on el ectric power only. It replac es the vehicle’s transmission with a single planetary gear and a moto r/generator. A second, more powerful motor/generator is directly c onnected to the vehicle’s final drive. The planetary gear splits the engine’s torque between the first mo tor/generator and the final drive. The first motor/generator uses power from the engine to either charge the ba ttery or supply powerV-131

to the wheels. The speed of the first motor/ge nerator determines the relative speed of the engine to the wheels. In th is way, the planetary gear a llows the engine to operate independently of vehicle speed, much like a CVT. The Toyota Prius and the Ford Hybrid Escape are two examples of power split hybrid vehicles.

In addition to providing the functions of id le engine stop and subsequent restart, regenerative braking, this hybrid system allows for pure EV operation. The two motor/generators are bigger and more powerfu l than those in an ISG hybrid, allowing the engine to be run in efficient operating zone s more often. For these reasons, the power split system provides very good fuel consump tion in city driving. During highway cycles, the hybrid functions of regenerative braking, engine start/stop and optimal engine operation cannot be applied as often as in city driving, and so the effectiveness in fuel consumption are less. Additiona lly, it is less efficient at highway speeds due to the fact that the first motor/generator must be spi nning at a relatively hi gh speed and therefore
incurs losses.

The battery pack for PSHEV is assumed to be 300V NiMH for the time period considered in this rulemaking, as is used in current PSHEV systems today. Their reliability is proven (having been in hybrids fo r over 10 years) and their cost is lower than Li Ion, so it is likely that the battery tec hnology used in HEVs will continue to be NiMH for the near future for hybrids that do not require high energy storage capability like a plug-in hybrid does.

The Power Split hybrid also reduces the cost of the transmission, replacing a conventional multi-speed unit with a single plan etary gear. The electric components are bigger than those in an ISG configuration so the costs are correspondingly higher.

However, the Power Split system is not pla nned for use on full-size trucks and SUVs due to its limited ability to efficiently provide the torque needed by these vehicles. The drive torque is limited to the first motor/generator’s capacity to resist the torque of the engine. It is anticipated that Large Trucks would use the 2-mode hybrid system.

In the NPRM, a phase-in rate of 3 percent was assumed for the power split technology. Although this system has been engineered for some vehicles by a couple of manufacturers, the required e ngineering resources both at OE Ms and Tier 1 suppliers are high . and most importantly, require long product development lead times. Thus NHTSA believes it would be extremely difficult for manufacturers to implement in levels greater than that of the submitted product pl ans for MY 2011. For the final rule, NHTSA limited the volumes of power split hybrid s to zero percent in MY 2011. Power split hybrid cost and effectiveness estimates will not be discussed he re, given that the technology is not applied in MY 2011 beyond pr oduct plan levels in NHTSA’s analysis, and NHTSA will consider them further in its future rulemaking actions.

The NPRM proposed that all of the hybrid t echnologies could be introduced during the redesign model year only, consistent with manuf acturer’s views. Given this, for this final
rule NHTSA has retained th e redesign application timing.V-132

(ix) 2-Mode Hybrid The 2-mode hybrid (2MHEV) is another strong hybrid system that has all-electric drive capability. The 2MHEV uses an adaptation of a conventional stepped-ratio automatic transmission by replacing some of the transm ission clutches with two electric motors, which makes the transmission act like a CVT. Like the Power Split hybrid, these motors control the ratio of engine speed to vehicle speed. But unlike the Power Split system, clutches allow the motors to be bypassed, wh ich improves both the transmission’s torque capacity and efficiency for improved fuel ec onomy at highway speeds. This type of system is used in the Chevy Tahoe Hybrid.

In addition to providing the hybrid functions of engine stop and s ubsequent restart and regenerative braking, the 2MHEV allo ws for pure EV operation. The two motor/generators are bigger and more powerfu l than those in an ISG hybrid, allowing the engine to be run in efficient operating zones more often. For these reasons, the 2-mode system also provides very good fuel ec onomy in city driving. The primary motor/generator is comparable in size to that in the PSHEV system, but the secondary motor/generator is larger. The 2-mode system cost is greater than that for the power split system due to the additional transmission complexity and secondary motor sizing.

The battery pack for 2MHEV is assumed to be 300V NiMH for the time period considered in this rulemaking, as is used in current 2MHEV systems today. Their reliability is proven (having been in hybrids fo r over 10 years) and their cost is lower than Li Ion, so it is likely that the batteries will continue to be NiMH for the near future for hybrids that do not require hi gh energy storage capability like a plug-in hybrid does.

Given the relatively large si ze of the 2 mode powertrain, th is technology was assumed to be applicable to the Small through Large Truck/SUV classes. In the NPRM, a phase-in rate of 3 percent was assumed for 2 mode hybrids. The 2-modes have recently been introduced in the marketplace on a few vehicle pl atforms. The engineering resources that
are needed both at the OEMs and Tier 1s to develop this across many more platforms are considerable, as discussed above for power sp lit hybrids. For purposes of the final rule, the phase-in rate has been set to zero pe rcent in MY 2011. 2 mode hybrid cost and
effectiveness estimates will not be discu ssed here, given that the technology is not applied in MY 2011 beyond product plan levels in NHTSA’s analysis, and NHTSA will
consider them further in its future rulemaking actions.

The NPRM proposed that all of the hybrid t echnologies could be introduced during the redesign model year only, consistent with manufact urer’s views. Given this, for this final
rule NHTSA has retained th e redesign application timing.

(x) Plug-In Hybrid Plug-In Hybrid Electric Vehicl es (PHEV) are very similar to other strong hybrid electric vehicles, but with significant functional differences. The key distinguishing feature is the ability to charge the battery pack from an outsi de source of electricity (usually the electric grid). A PHEV would have a larger battery pack with gr eater energy capacity, and anV-133

ability to be discharged furt her (referred to as “depth of discharge”). No major manufacturer currently has a PHEV in pr oduction, although both GM and Toyota have publicly announced that they will launch plug-in hybrids in limited volumes by 2010.

PHEVs offer a significant opportuni ty to displace petroleum-de rived fuels with electricity from the electrical grid. The reduction in petroleum use depends on the electric-drive range capability and the vehicle usage ( i.e. , trip distance between recharging, ambient temperature, etc.). PHEVs can have a wide variation in the All Electric Range (AER) that they offer. Some PHEVs are of the “blended” type where the engine is on during most of the vehicle operation, bu t the proportion of electric energy that is used to propel the vehicle is significantly higher than that used in a PSHEV or 2MHEV.

PHEVs were not projected to be in volume use in the NPRM, but due to confidential manufacturer product plans, PHEVs do, in fact , appear in limited volumes in the final rule analysis, and therefore low volume, unlearned costs are assumed. However, the manufacturer-stated production volumes of PHEVs ar e very low, so the phase-in cap for MY 2011 is zero—given the considerable engineer ing hurdles, the low availability of LiIon batteries in the MY 2011 time frame and the reasons discussed above for power split and 2 mode hybrids, NHTSA did not believe th at PHEVs could be applied to more MY 2011 vehicles beyond what was indicated in the product plans. Additionally, plug-in hybrid cost and effectiveness estimates will not be discussed he re, given that the technology is not applied in MY 2011 beyond pr oduct plan levels in NHTSA’s analysis, and NHTSA will consider them further in its future rulemaking actions. The NPRM proposed that all of the hybrid technologi es could be introduced during the redesign model year only, consistent with manufacturer’s views. Give n this, for this final rule NHTSA has allowed application of PHEVs in redesign model years only.

(e) Vehicle Technologies (i) Material Substitution (MS1, MS2, MS5) The term “material substitution” encompasses a variety of techniques with a variety of costs and lead times. These techniques ma y include using lighte r-weight and/or higherstrength materials, redesigning components, and size matching of components. Lighterweight materials involve usi ng lower-density materials in vehicle components, such as replacing steel parts with aluminum or pl astic. The use of hi gher-strength materials
involves the substitution of one material fo r another that possesses higher strength and less weight. An example would be using high st rength alloy steel versus cold rolled steel. Component redesign is an ongoing process to reduce costs and/ or weight of components, while improving performance and reliabilit y. The Aluminum Association commented that lightweight structures ar e a significant enabler for the new powertrain technologies. Smaller and less expensive powertrains are required and the combination of reduced power and weight reduction positively reinforce and result in optimal fuel economy performance. An example would be a subsystem replacing multiple components and mounting hardware.

However, the cost of reducing weight is difficult to determine and depends upon the methods used. For example, a change in de sign that reduces wei ght on a new model mayV-134

or may not save money. On the other hand, mate rial substitution can re sult in an increase in price per application of the technology if more expensive materials are used. As discussed further below, for purposes of th is final rule, NHTSA has considered only vehicles weighing greater than 5,000 lbs (curb weight) for weight reduction through materials substitution. A typical BOM for Mate rial Substitution would include primarily substitution of high strength steels for heavie r steels or other stru ctural, materials on a
vehicle. This BOM was established for each class but was not adjusted for each class due to the fact that the vehicle technology of Material Substitution is already scaled by it being based on percent of curb weight at or over 5,000 lbs.

In the NPRM, NHTSA estimated fuel economy effectiveness of a 2 percent incremental reduction in fuel consumption per each 3 pe rcent reduction in vehicle weight. Nissan commented that NHTSA’s modeling of mate rial substitution application was overly optimistic, but did not elaborate further. Confidential manufacturer comments in response to the NPRM did not provide standard ized effectiveness estimates, but ranged from 3.3 to 3.9 percent mpg improvement for a 10 percent reduction in mass, to 0.20 to 0.75 percent per 1 percent weight reduction, to 1 percent redu ction on the FTP city cycle per 100 lbs reduced, with a maximum possi ble weight reduction of 5 percent.

Bearing in mind that NHTSA only assumes materi al substitution for vehicles at or above 5,000 lbs curb weight and based on manufactur er comments which together suggest an incremental improvement in fuel consumption of approximately 0.60 percent to 0.9 percent per 3 percent reduction in material weight, NHTSA has estimated an incremental improvement in fuel consumption of 1 percen t (corresponding to a 3 percent reduction in vehicle weight, or roughly 0.35 percent fuel consumption per 1 percent reduction in vehicle weight). This estimate is consiste nt with the majority of the manufacturer

comments.

As for costs, in the NPRM NHTSA estim ated incremental costs of $0.75 to $1.25 per pound reduced through material substitution. The costs for material substitution were not clearly commented on in the confidential manufacturer responses. Confidential manufacturer estimates ranged from $50 to $511 for 1 percent reduction, although in most cases the cost estimates were not for the entire range of substitution (1-5 percent) and did not provide any additi onal clarification on how they specifically applied to the material substitution technology. Consequently , for purposes of the final rule NHTSA retained the existing NPRM cost estimates with adjustments to 2007 dollar levels resulting in an incremental $1 to $2 per pound of substituted material, which applies to the MS1 and MS2 technology, and $2 to $4 pe r pound for the MS5 technology. Costs for material substitution are not adjusted by vehi cle subclass, as the technology costs are based on a percentage of the vehicle wei ght (per pound) and limited to Medium and Large Truck/SUV Van subclasses above 5,000 lbs curb weight.

The agency notes that comments from th e Alliance and the Aluminum Association associated engine downsizing with weight reduction/material substitution and quoted
effectiveness for this action as well. NHT SA considers engine downsizing separatelyV-135

from typical material substitution efforts, and consequently did not include those cost and fuel economy effectiveness for this technology.

In the NPRM, NHTSA assumed a 17 percent phase-in rate for material substitution. NHTSA received only one confidential ma nufacturer comment regarding material substitution phase-in percentage, suggesting 17 to 30 percent, but the agency notes that it generally received comments suggesting a non-l inear phase-in rate for this technology,
that would start at a rate lo wer than the current NPRM value and increase over time. In response to these comments, NHTSA revise d the MY 2011 phase-in percentage to 5 percent to account for lead time limitations.

For material substitution t echnologies, neither volume-bas ed cost reductions nor timebased cost reductions are applied. This tec hnology does not employ a particular list of components to employ credible cost reduction.

In the NPRM, NHTSA assumed that material substitution (1 percent) could be applied during a redesign model year only. For th is final rule, based on confidential manufacturer comments, NHTSA estimated that material substitution (1 percent) could be applied during either a refresh or a redesign model year, due to minimal design changes with minimal component or vehicl e-level testing require d. However, NHTSA retained the assumption that material substi tution (2 percent and 5 percent) could be applied during redesign model year only, as in the NPRM, because the agency neither received comments to contradict this assump tion nor found other data to substantiate a change. The technology title was changed from Material Substitution (3 percent) to Material Substitution (5 percent) to more accurately represent the cumulative amount for the technology.

(ii) Low Drag Brakes (LDB) Low drag brakes reduce the sliding friction of disc brake pads on rotors when the brakes are not engaged because the brake pads are pulled away from the rotating rotor. A typical BOM for Low Drag Brakes would t ypically include changes in brake caliper speed by changing the brake control system, springs, etc. on a vehicles brake system.
This BOM was established for each class and was not adjusted for each class due to the
fact that the vehicle technol ogy BOM would not change by cla ss across vehicle classes.
Confidential manufacturer comments in res ponse to the NPRM indicated that most passenger cars have already adopted this te chnology, but that ladder frame trucks have not yet adopted this technol ogy. Consequently, in the fi nal rule this technology was assumed to be applicable only to the Larg e Performance Passenger Car and Medium and Large Truck classes.

In the NPRM, NHTSA assumed an incremental improvement in fuel consumption of 1 to 2 percent for low drag brakes. Confidential manufacturer comments submitted in response to the NPRM indicated an effectiv e range of 0.5-1.0 percen t for this technology and this range was applied in the final rule. As for costs, NHTSA assumed in the NPRM incremental costs of $85 to $90 for the addition of low drag brakes. For the final rule,V-136

NHTSA took the average and adjusted it to 2007 dollars to establish an $89 final rule

cost.

The NPRM assumed an annual average phase-in ra te for low drag brak es of 25 percent. For the final rule, the phase-in cap is 20 per cent. No learning cu rve was applied in the NPRM but for the final rule, low drag brakes were considered a high volume, mature and stable technology, and thus time-based lear ning was applied. Low drag brakes are
assumed in the final rule to be applicable at refresh cycle only.

(iii) Low Rolling Resistance Tires (ROLL) Tire rolling resistance is the frictional loss associated mainly with the energy dissipated
in the deformation of the tires under load – and thus, influence fuel economy. Other tire design characteristics ( e.g. , materials, construction, and tr ead design) influence durability, traction control (both wet and dry grip), vehi cle handling, and ride comfort in addition to rolling resistance. A typical low rolling re sistance tires BOM would include: tire inflation pressure, material change, and cons tructions with less hysteresis, geometry changes ( e.g. , reduced aspect ratios), reduction in si dewall and tread deflection, potential spring and shock tuning. Low rolling resistance tires are applicable to all classes of vehicles, except for ladder frame light truc ks and performance ve hicles. NHTSA assumed that this technology should not be applied to vehicles in th e Large truck class due to the increased traction and handling requirements for off-road and braking performance at payload and towing limits which cannot be met with low resistance tire designs. Likewise, this technology was not applied to vehicles in th e Performance Car classes due to increased traction requirements for brak ing and handling which cannot be met with low roll resistance tire designs. Confidential manufacturer comments received regarding applicability of this tech nology to particular vehicle classes confirmed NHTSA’s assumption.

In the NPRM, NHTSA assumed an incremental reduction in fuel consumption of 1 to 2 percent for application of lo w rolling resistance tires. Confidential manufacturer comments varied widely and addressed the conf licting objectives of increasing safety by increasing rolling resistance for better tire traction, and improving fuel economy with lower rolling resistance tires that provid e reduced traction. C onfidential manufacturer comments suggested fuel consumption effectiv eness of negative impact to a positive 0.1 percent per year over the next five y ears from 2008, while other confidential
manufacturer comments indicate that the percentage effectiveness of low rolling resistance tires would increase each year , although it would apply differently for performance classes. Confid ential manufacturer comments al so indicated that some manufacturers have already a pplied this technology and c onsequently would receive no
further effectiveness from this technol ogy. The 2002 NAS Report indicated that an assumed 10 percent rolling resistance reduc tion would provide an increase in fuel economy of 1 to 2 percent. NHTSA believes th e NAS effectiveness is still valid and used 1 to 2 percent incremental reduction in fuel consumption for application of low rolling
resistance tires in the final rule.V-137

NHTSA estimated the incremental cost of f our low rolling resistance tires to be $6 per vehicle in the NPRM, independent of vehicl e class, although not a pplicable to large trucks. NHTSA received few specific commen ts on the costs of applying low rolling
resistance tires however conf idential manufacturer comments that were received provided widely ranging and higher costs. NHTSA increased the range from the NPRM cost estimates to $6 to $9 per ve hicle in the final rule.

In the NPRM, NHTSA assumed an annual phase -in rate of 25 per cent for low rolling
resistance tires. Confidential manufacturer comments on the phase-in rate for low rolling resistance tires varied, with some suggesti ng that many vehicle clas ses already had high phase-in rates planned or accomplished. As discussed above, the comments also suggested a non-linear phase-in plan over th e 5-year period. Conf idential manufacturer data was in the 25-30 percent range. Ba sed on confidential manufacturer comments received and NHTSA’s analysis, the final rule includes a phase-in cap for low rolling resistance tires with a phase-in rate of 20 percent for MY 2011.

For low rolling resistant tire technology, neith er volume-based cost reductions nor timebased cost reductions are applied. This te chnology is presumed to be significantly dependent on commodity raw material prices an d to be priced indepe ndent of particular design or manufacturing savings.

In the NPRM, NHTSA assumed that low rollin g resistance tires c ould be applied during any model year. However, based on conf idential manufacturer comments NHTSA recognizes that there are some vehicle attribute impacts which may result from application of low rolling resistance tires, such as changes to vehicle dynamics and braking. Vehicle validation testing for safe ty and vehicle attri bute prove-out is not usually planned for every model year, so NHTSA assumed that th is technology can be applied during a redesign or refresh mode l year for purposes of the final rule.

(iv) Front or Secondary Axle Disconne ct for Four-Wheel Drive Systems (SAX) To provide shift-on-the-fly capabilities, reduc e wear and tear on secondary axles, and improve performance and fuel economy, many part-time four-wheel drive (4WD) systems use some type of axle disconnect. Axle disconnects are typically used on 4WD vehicles with two-wheel drive (2WD) ope rating modes. When shifting from 2WD to 4WD “on the fly” (while moving), the front axle disconnect couples the front driveshaft to the front differential side gear only when the transfer case’s synchronizing mechanism has spun the front driveshaft, transfer case chain or gear set and differential carrier up to the same speed as the rear driveshaft. 4WD sy stems that have axle disconnect typically
do not have either manual- or automatic-locking hubs. For ex ample, to isolate the front wheels from the rest of the front driveline, front axle disconnects us e a sliding sleeve to
connect or disconnect an axle shaft from the front differential side gear. The effectiveness to fuel efficiency is create d by reducing inertial, chain, bearing and gear losses (parasitic losses).

Full time 4WD or all-wheel-drive (AWD) sy stems used for on-road performance and safety do not use axle disconnect systems due to the need for instan taneous activation ofV-138

torque to wheels, and the agency is not awar e of any manufacturer or suppliers who are developing a system to allow secondary axle disconnect suitable for use on AWD systems at this time. Secondary axle di sconnect technology is primarily found on solid axle 4WD systems and not on the transaxle a nd/or independent axle systems typically found in AWD vehicles; thus, th e application of this tec hnology to AWD systems has not been considered for purposes of this rule making. The technology will be evaluated in future rulemakings.

Vehicle technology BOM information was not adju sted by vehicle classe s due to the fact that the vehicle technology is limited to transfer case and front axle design changes. Scaling of components might be impacted but the components themselves will be the
same. This is consistent with NHTSA’s assumptions in the NPRM, and is supported by comments from confidential supplier and manu facturers. Secondary Axle Disconnect BOM typically involves a transfer case wh ich includes electronic solenoid with clutch system to disconnect front drive and using axle mounted vacuum or electric disconnect
that still allows driveshaft rotati on without connection to wheel ends.

In the NPRM, NHTSA employed “unibody” and “ladder frame” terms to differentiate application of this technology, and had s uggested “unibody” AWD systems could apply this same technology. In actuality, most 4W D vehicles are “ladder frame” technology and AWD are “unibody” designs (which for the reasons stated above will not be considered for this technology). Ladder fr ame technology is typically associated with greater payload, towing, and off-road capab ility, whereas unibody designs are typically used in smaller, usually front-wheel drive ve hicles, and are typically not associated with higher payload, towing, and off-road use. For the final rule, NHTSA removed these vehicle design criteria since it is not a requirement to incorporate axle disconnect technology, only a historical design point a nd vehicle manufacturers should not be limited to a specific vehicle or chassis configur ation to apply this technology. Therefore, this technology is applicable to 4WD vehicl es in all vehicle classes (independent of chassis or frame design).

In the NPRM, NHTSA estimated an incrementa l reduction in fuel consumption of 1 to 1.5 percent for axle disconnect. Confiden tial manufacturer comments suggested an incremental effectiveness of 1 to 1.5 pe rcent. Supported by this confidential manufacturer data, NHTSA maintained an in cremental effectiveness of 1 to 1.5 percent
for axle disconnect for the final rule.

As for costs, the NPRM estimated the in cremental cost for adding axle disconnect technology at $114 for 4WD systems and the $676 estimate was for the AWD systems which are not applied in the final rule. NHTSA received no specific comments on costs for this technology and found no additional sources to support a change from this value for the 4WD value of $114, so for purposes of the final rule, NHTSA revised the $114 figure to 2007 dollars to esta blish a $117 final rule cost.

In the NPRM, NHTSA assumed a phase-in cap of 17 percent for secondary axle disconnect for each model year covered by th e rulemaking. No specific comments wereV-139

received regarding the phase-in rate fo r this technology, but as discussed above, manufacturers generally argue d for a non-linear phase-in pl an over the 5-year period covered by the rulemaking. Based on general comments received and NHTSA’s analysis,
the final rule includes an aver age annual phase-in rate for secondary axle disconnect of 17 percent for MY 2011.

In the NPRM, NHTSA assumed a volume-based learning curve factor of 20 percent for secondary axle disconnect. For the final ru le, secondary axle disconnect learning was
established as time-based due to confidential ma nufacturer data demonstrating that this is a mature technology, such that additional volumes will provide no additional advantage for incorporation by manufacturers.

In the NPRM, NHTSA assumed that secondary axle disconnect could be applied to a vehicle either during refresh or redesign model years. NHTSA received no comments and found no sources to disagree with this assumption, and si nce testing to validate the functional requirements and vehi cle attribute prove-out testin g is usually not planned for every model year, NHTSA has retained this assumption for the final rule.

(v) Aerodynamic Drag Reduction (AERO) Several factors affect a vehicle’s aerodynami c drag and the resulting power required to move it through the air. While these values change with ai r density and the square and cube of vehicle speed, respect ively, the overall drag effect is determined by the product of its frontal area and drag coefficient. Reductions in these qua ntities can therefore reduce fuel consumption. While frontal areas tend to be relativel y similar within a vehicle class (mostly due to market-competitive size requirements), significant variations in drag coefficient can be observed. Significant fleet aer odynamic drag reductions may require incorporation into a manufacturer ’s new model phase-in schedules depending on
the mix of vehicle classes distributed across the manuf acturer’s lineup. However, shorter-term aerodynamic reductions, with less of a fuel economy effectiveness, may be achieved through the use of revised exterior co mponents (typically at a model refresh in mid-cycle) and add-on devices th at are in general circulation today. The latter list would
include revised front and rear fascias, modified front air da ms and rear valances, addition of rear deck lips and underbody panels, and more efficient exterior mirrors.

Vehicle technology BOM information was not adju sted by vehicle classe s due to the fact that Aero Drag Reductions are already scaled based on percent overall vehicle coefficient of drag CdA. Aero Drag Reduction BOM coul d include (but would not be limited to) the following components or subsystems: under body covers, front lower air dams, overall front fascia changes, headlight s, hood, fenders, grill, windshield angle, A-Pillar angle, door seal gaps, roof (which would both be high impact and very high cost), side view mirrors, door handles (low impact), ride heig ht, rear deck lip, wheels, wheel covers, and optimizing the cooling flow path.

In the NPRM, NHTSA estimated an incr emental aerodynamic drag reduction of 20 percent for cars, and 10 percent for truc ks. Confidential manufacturer comments received indicated that the 20 percent reduc tion for cars in the NPRM may have beenV-140

overly optimistic, as significant changes in aero drag have already b een applied to those vehicle classes. However, confidential manufacturer comments agreed with the 10 percent aerodynamic drag reduction for truc ks, since there are still significant opportunities to improve aero drag in trucks desi gned for truck-related utility. The Sierra Research study submitted by the Alliance concluded that a 10 percent incremental aerodynamic drag reduction for mid-size cars gi ves a 1.5 percent improvement in vehicle fuel economy. Thus, for purposes of the fina l rule, NHTSA has estimated that a fleet average of 10 percent total aerodynamic drag reduction is attainab le (with a caveat for “high-performance” vehicles described below) , which equates to incremental reductions in fuel consumption of 2 percent and 3 per cent for cars and trucks, respectively. These numbers are in agreement with public ly-available technical literature 205 and are supported by confidential manufacturer information. Performance car classes are excluded from this technology improvement because they have largely applied this technology already.

As for costs, in the NPRM NHTSA assumed an incremental cost of $0 to $75 for aero drag reduction on both cars and trucks. After reviewing the 2008 Martec Report, however, NHTSA concluded that a lower-bound cost of $0 was not supportable. NHTSA replaced the lower-bound cost with $40 (non-RPE) based on the assumptions that the underbody cover and acoustic cove rs described in the Mart ec report approximates the cost for one large underbody c over as might be required for minimal aero drag reduction
actions. 206 The upper limit was determined by updating the NPRM upper cost to 2007 dollars and applying an RPE uplift thereby es tablishing the incremental cost, independent of vehicle class, to range from $60 to $116 (RPE) for the final rule

In the NPRM, NHTSA assumed a 17 percent phase-in rate for aero drag reduction for each model year covered by the rulemaking. No specific comments were received regarding the phase-in rate for this tec hnology, but as discussed above, manufacturers generally argued for a non-linear phase-in plan over a 5-year period. Based on comments received and NHTSA’s analysis, the final ru le includes an phase-in rate for aero drag reduction of 17 percent in MY 2011. Neithervolume-based cost reductions nor timebased cost reductions are applied. In th e NPRM, NHTSA assumed that aero drag reduction could be applied in either a re fresh or a redesign model year and that assumption has been retained for the final rule.

(f) Technologies considered but not included in the final rule analysis Although discussed and considered as poten tially viable in the NPRM, NHTSA has determined that three technologies will be una vailable in the time frame considered. These technologies have been identified as either pre-emerging or not technologically feasible. Pre-emerging technologi es are those that are still in the research phase at this time, and which are not expected to be unde r development for production vehicles for

205 Sue Elliott-Sink, “Improving Aerodynamics to Boost Fuel Economy,” May 2, 2006. Available at http://www.edmunds.com/advice/fueleco nomy/articles/106954/ar ticle.html (last accessed Oct. 5, 2008).

198 2008 Martec Report, at 25. NHTSA also assumed that the cost of fuel pulsation dampening technology noted in the Martec report grouped with the underbody cover and acoustic covers does not significantly impact the $40 cost as fuel pulsation dampening technology is very low in cost relative to the other actions. Therefore NHTSA did not modify the $40 estimate.V-141

several years. In another case, the tec hnology depends on a fuel that is not readily available. Thus, for the reasons discussed be low, these technologies were not considered in NHTSA’s analysis for the final rule. The technologies are camless valve actuation (CVA), lean burn gasoline direct injecti on (LBDI), homogeneous charge compression ignition (HCCI), and electric assist tur bocharging. Although not applied in this rulemaking, NHTSA will continue to monito r the industry and system suppliers for progress on these technologies, and should they become available, consider them for use in any future rulemaking activity.

(i) Camless Valve Actuation
Camless valve actuation relies on electromechan ical actuators instead of camshafts to open and close the cylinder valves. When electromechanical actuators are used to replace cams and coupled with sensors and microproces sor controls, valve timing and lift can be optimized over all conditions. An engine valv etrain 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 variabil ity, the rapid response required to change between operating modes (such as HCCI and GDI), intake valve throttling, cylinder deactivation, and elimination of the camshafts (redu ced friction). This
level of control can enable even further incr emental reductions in fuel consumption.

As noted in the NPRM, this technology ha s been under research for many decades and although some progress is being made, NHTSA has found no evidence to support that the technology can be successfully implemented, co sted, or have defined fuel consumption
effectiveness at this time.

(ii) Lean-Burn Gasoline Di rect Injection Technology One way to improve an engine’s thermodynami c efficiency dramatically is by operating at a lean air-fuel mixture (excess air). Fu el 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 pr ecision and targeti ng towards the spark plug, increasing lean combustion stabilit y. Combined with advances in NO

x aftertreatment, lean-burn GDI engines may eventually be a possibility in North America.

However, as noted in the NPRM, a key tech nical requirement for lean-burn GDI engines
to meet EPA’s Tier 2 NO

x emissions levels is the availa bility of low-sulfur gasoline, which is projected to be unavailable during the time frame considered. Therefore the technology was not applied in the final rule

(iii) Homogeneous Charge Compression Ignition Homogeneous charge compression ignition (HCCI), also referre d to as controlled auto ignition (CAI), is an alternat e engine operating mode that do es not rely on a spark event to initiate combustion. The principles are mo re closely aligned with a diesel combustion cycle, in which the compressed charge exceed s a temperature and pressure necessary for spontaneous ignition. The resulting burn is mu ch shorter in duration with higher thermal efficiency. Shorter combustion times a nd higher EGR tolerance permit very highV-142

compression ratios (which also increase thermodynamic efficiency), and additionally, pumping losses are reduced because the engine can run unthrottled.

NHTSA noted in the NPRM that several manuf acturers had made public statements about the viability of incorporati ng HCCI into production vehicles over the next 10 years. Upon further review of confidential product plan information, and reviewing comments received in response to the NPRM, NHTSA has determined the technology will not be
available within the time frame considere d. Consequently, the technology was not applied in the final rule.

(iv) Electric Assist Turbocharging The Alliance commented that global development of electric assist turbocharging has not demonstrated the fuel efficiency effectiv eness of a 12V EAT up to 2kW power levels since the 2004 NESCCAF study, and stated that it saw remote probability of its application over the next decade. 207 While hybrid vehicles lower the incremental hardware requirements for higher-voltage, higher-power EAT systems, NHTSA believes that significant development work is require d to demonstrate effective systems and that implementation in significant volumes will not occur in the time frame considered. Thus, this technology was not included on the decision trees.

E. Cost and effectiveness tables The tables representing the Volpe model i nput files for incremental technology costs by vehicle subclass are presented below. The ta bles have been divided into passenger cars, performance passenger cars, and light tr ucks to make them easier to read.

207 NHTSA-2008-0089-0169.1, at 41.V-143

Table V-15. Technology Incremental Cost Estimates, Passenger Cars

Subcompac Compact Midsize Large

Ca r Ca r Ca r Ca r Inline 4 Inline 4 Inline 4 V6

Low Friction Lubricants LUB 5 5 5 5 Engine Friction Reduction EFR 52 - 196 52 - 196 52 - 196 78 - 294 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 61 61 61 122

Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 201 201 201 306 Cylinder Deactivation on SOHC DEACS n.a. n.a. n.a. 75 VVT - Intake Cam Phasing (ICP) ICP 61 61 61 122 VVT - Dual Cam Phasing (DCP) DCP 61 61 61 122

Discrete Variable Valv e Lift (DVVL) on DOHC DVVLD 201 201 201 306 Continuously Variable Valve Lift (CVVL) CVVL 306 306 306 432 Cylinder Deactivation on DOHC DEACD n.a. n.a. n.a. 75 Cylinder Deactivation on OHV DEACO n.a. n.a. n.a. 306 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 61 61 61 122

Discrete Variable Valv e Lift (DVVL) on OHV DVVLO 201 201 201 76

Conversion to DOHC with DCP CDOHC 373 373 373 590 Stoichiometric Gasoline Direct Injection (GDI) SGDI 293 - 440 293 - 440 293 - 440 384 - 558 Turbocharging and Downsizing TRBDS 1223 1223 1223 822

Conversion to Diesel following CBRST DSLC 2,963 - 3,254 2,963 - 3,254 2,963 - 3,254 4,105 - 4,490

Conversion to Diesel following TRBDS DSLT 1,567 - 1,858 1,567 - 1,858 1,567 - 1,858 3,110 - 3,495 Electric Power Steering EPS 105 - 120 105 - 120 105 - 120 105 - 120 Improved Accessories IACC 173 - 211 173 - 211 173 - 211 173 - 211 12V Micro-Hybrid MHEV 372 408 453 490 Higher Voltage/Improved Alternator HVIA 84 84 84 84 Integrated Starter Generator (Belt/Crank) ISG 1713 2019 2190 2386 6-Speed Manual/Impr oved Internals 6MAN 338 338 338 338 Improved Auto. Trans. Controls/Externals IATC 59 59 59 59 Continuously Variable Transmission CVT 300 300 300 300 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 323 323 323 323

Dual Clutch or Automate d Manual Transmission DCTAM 68 68 218 218 Material Substitution (1%) MS1 n.a. n.a. n.a. n.a. Material Substitution (2%) MS2 n.a. n.a. n.a. n.a. Material Substitution (5%) MS5 n.a. n.a. n.a. n.a. Low Rolling Resistance Tires ROLL 6 - 9 6 - 9 6 - 9 6 - 9 Low Drag Brakes LDB n.a. n.a. n.a. n.a. Secondary Axle Disconnect SAX 117 117 117 117 Aero Drag Reduction AERO 60 - 116 60 - 116 60 - 116 60 - 116 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY RETAIL PRICE EQUIVALENT INCREMENTAL COSTS PER VEHICLE ($) BY VEHICLE TECHNICAL CLASS - PASSENGER CARSV-144

Table V-16. Technology Incremental Cost Estimates, Performance Passenger Cars

Perform. Perform. Perform. Perform. Subcomp. Compact Midsize Large

Ca r Ca r Ca r Ca r Inline 4 V6 V6 V8

Low Friction Lubricants LUB 5555 Engine Friction Reduction EFR 52 - 196 78 - 294 78 - 294 104 - 392 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 61 122 122 122

Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 201 306 306 396 Cylinder Deactivation on SOHC DEACS n.a. 75 75 75 VVT - Intake Cam Phasing (ICP) ICP 61 122 122 122 VVT - Dual Cam Phasing (DCP) DCP 61 122 122 122

Discrete Variable Valv e Lift (DVVL) on DOHC DVVLD 201 306 306 396 Continuously Variable Valve Lift (CVVL) CVVL 306 432 432 582 Cylinder Deactivation on DOHC DEACD n.a. 75 75 75 Cylinder Deactivation on OHV DEACO n.a. 306 306 400 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 61 122 122 122

Discrete Variable Valv e Lift (DVVL) on OHV DVVLO 201 76 76 76

Conversion to DOHC with DCP CDOHC 373 590 590 746 Stoichiometric Gasoline Direct Injection (GDI) SGDI 293 - 440 384 - 558 384 - 558 512 - 744 Turbocharging and Downsizing TRBDS 1,223 822 822 1,229

Conversion to Diesel following CBRST DSLC 2,963 - 3,254 4,105 - 4,490 4,105 - 4,490 5,125 - 5,617

Conversion to Diesel following TRBDS DSLT 1,567 - 1,858 3,110 - 3,495 3,110 - 3,495 3,723 - 4,215 Electric Power Steering EPS 105 - 120 105 - 120 105 - 120 105 - 120 Improved Accessories IACC 173 - 211 173 - 211 173 - 211 173 - 211 12V Micro-Hybrid MHEV 406 443 494 549 Higher Voltage/Improved Alternator HVIA 84 84 84 84

Integrated Starter Generator (Belt/Crank) ISG 1,789 - 1,864 2,054 2,183 2,351 6-Speed Manual/Impr oved Internals 6MAN 338 338 338 338 Improved Auto. Trans. Controls/Externals IATC 59 59 59 59 Continuously Variable Transmission CVT 300 300 300 n.a. 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 323 - 638 323 - 638 323 - 638 323 - 638

Dual Clutch or Automate d Manual Transmission DCTAM (97) - 218 (97) - 218 (97) - 218 (97) - 218 Material Substitution (1%) MS1 n.a. n.a. n.a. n.a. Material Substitution (2%) MS2 n.a. n.a. n.a. n.a. Material Substitution (5%) MS5 n.a. n.a. n.a. n.a. Low Rolling Resistance Tires ROLL n.a. n.a. n.a. n.a. Low Drag Brakes LDB n.a. n.a. n.a. n.a. Secondary Axle Disconnect SAX 117 117 117 117 Aero Drag Reduction AERO 60 - 116 60 - 116 60 - 116 60 - 116 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY RETAIL PRICE EQUIVALENT INCREMENTAL COSTS PER VEHICLE ($) BY VEHICLE TECHNICAL CLASS - PERFORMANCE CARSV-145

Table V-17. Technology Incremental Cost Estimates, Light Trucks

Minivan Small Midsize Large

LT LT LT LT
V6 Inline 4 V6 V8

Low Friction Lubricants LUB 5 5 5 5 Engine Friction Reduction EFR 78 - 294 52 - 196 78 - 294 104 - 392 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 122 61 122 122

Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 306 201 306 396 Cylinder Deactivation on SOHC DEACS 75 n.a. 75 75 VVT - Intake Cam Phasing (ICP) ICP 122 61 122 122 VVT - Dual Cam Phasing (DCP) DCP 122 61 122 122

Discrete Variable Valv e Lift (DVVL) on DOHC DVVLD 306 201 306 396 Continuously Variable Valve Lift (CVVL) CVVL 432 306 432 582 Cylinder Deactivation on DOHC DEACD 75 n.a. 75 75 Cylinder Deactivation on OHV DEACO 306 n.a. 306 400 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 122 61 122 122

Discrete Variable Valv e Lift (DVVL) on OHV DVVLO 76 201 76 76

Conversion to DOHC with DCP CDOHC 590 373 590 746 Stoichiometric Gasoline Direct Injection (GDI) SGDI 384 - 558 293 - 440 384 - 558 512 - 744 Turbocharging and Downsizing TRBDS 822 1223 822 1229

Conversion to Diesel following CBRST DSLC 4,105 - 4,490 2,963 - 3,254 4,105 - 4,490 5,125 - 5,617

Conversion to Diesel following TRBDS DSLT 3,110 - 3,495 1,567 - 1,858 3,110 - 3,495 3,723 - 4,215 Electric Power Steering EPS 105 - 120 105 - 120 105 - 120 n.a. Improved Accessories IACC 173 - 211 173 - 211 n.a. n.a. 12V Micro-Hybrid MHEV 490 427 502 n.a. Higher Voltage/Improved Alternator HVIA 84 84 84 n.a. Integrated Starter Generator (Belt/Crank) ISG 2386 2029 2457 n.a. 6-Speed Manual/Impr oved Internals 6MAN 338 338 338 338 Improved Auto. Trans. Controls/Externals IATC 59 59 59 59 Continuously Variable Transmission CVT 300 300 n.a. n.a. 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 323 323 - 638 323 - 638 323 - 638

Dual Clutch or Automate d Manual Transmission DCTAM 218 (97) - 218 (97) - 218 (97) - 218 Material Substitution (1%) MS1 n.a. n.a. 1 - 2 1 - 2 Material Substitution (2%) MS2 n.a. n.a. 1 - 2 1 - 2 Material Substitution (5%) MS5 n.a. n.a. 2 - 4 2 - 4 Low Rolling Resistance Tires ROLL 6 - 9 6 - 9 6 - 9 n.a. Low Drag Brakes LDB n.a. n.a. 89 89 Secondary Axle Disconnect SAX 117 117 117 117 Aero Drag Reduction AERO 60 - 116 60 - 116 60 - 116 60 - 116 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY RETAIL PRICE EQUIVALENT INCREMENTAL COSTS PER VEHICLE ($) BY VEHICLE TECHNICAL CLASS - LIGHT TRUCKSV-146

The tables representing the Volpe mode l input files for incremental technology effectiveness values by vehicle subclass are presented below. The tables have been divided into passenger cars, performance passeng er cars, and light trucks to make them
easier to read.Table V-18. Technology Incremental Effe ctiveness Estimates, Passenger Cars

Subcompact Compact Midsize Large

Car Car Car Car

Inline 4 Inline 4 Inline 4 V6

Low Friction Lubricants LUB 0.5 0.5 0.5 0.5 Engine Friction Reduction EFR 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Cylinder Deactivation on SOHC DEACS n.a. n.a. n.a. 2.5 - 3.0 VVT - Intake Cam Phasing (ICP) ICP 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Dual Cam Phasing (DCP) DCP 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Discrete Variable Valve Lift (DVVL) on DOHC DVVLD 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Continuously Variable Valve Lift (CVVL) CV VL 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 Cylinder Deactivation on DOHC DEACD n.a. n.a. n.a. 0 - 0.5 Cylinder Deactivation on OHV DEACO n.a. n.a. n.a. 3.9 - 5.5 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Discrete Variable Valve Lift (DVVL) on OHV DVVLO 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6

Conversion to DOHC with DCP CDOHC 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 Stoichiometric Gasoline Direct Injection (GDI ) SGDI 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 Turbocharging and Downsizing TRBDS 4.5 - 5.2 4.5 - 5.2 4.5 - 5.2 2.1 - 2.2 Conversion to Diesel following CBRST DSLC 15.0 - 15.3 15.0 - 15.3 13.8 - 14.2 11.1 - 12.0 Conversion to Diesel following TRBDS DSLT 6.6 - 7.7 6.6 - 7.7 5.3 - 6.5 5.3 - 6.5 Electric Power Steering EPS 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 Improved Accessories IACC 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 12V Micro-Hybrid MHEV 1.0 - 2.9 1.0 - 2.9 3.4 - 4.0 3.4 - 4.0 Higher Voltage/Improved Alternator HVIA 0.2 - 0.9 0.2 - 0.9 0.2 - 0.6 0.2 - 0.6 Integrated Starter Generator (Belt/Crank) ISG 5.7 - 6.5 5.7 - 6.5 5.7 - 6.5 5.7 - 6.5 6-Speed Manual/Improved Internals 6MAN 1 1 1 1 Improved Auto. Trans. Controls/Externals IATC 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 Continuously Variable Transmission CVT 0.7 - 2.0 0.7 - 2.0 0.7 - 2.0 0.7 - 2.0 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4

Dual Clutch or Automated Manual Transmission DCTAM 5.5 - 7.5 5.5 - 7.5 2.7 - 4.1 2.7 - 4.1 Material Substitution (1%) MS1 n.a. n.a. n.a. n.a. Material Substitution (2%) MS2 n.a. n.a. n.a. n.a. Material Substitution (5%) MS5 n.a. n.a. n.a. n.a. Low Rolling Resistance Tires ROLL 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 Low Drag Brakes LDB n.a. n.a. n.a. n.a. Secondary Axle Disconnect SAX 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Aero Drag Reduction AERO 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY INCREMENTAL FUEL CONSUMPTION REDUCTION (-%) BY VEHICLE

TECHNOLOGY CLASS - PASSENGER CARSTable V-19. Technology Incremental Effectiveness Estimates,
Performance Cars

Perform. Perform. Perform. Perform. Subcomp. Compact Midsize Large

Car Car Car Car

Inline 4 V6 V6 V8

Low Friction Lubricants LUB 0.5 0.5 0.5 0.5 Engine Friction Reduction EFR 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Cylinder Deactivation on SOHC DEACS n.a. 2.5 - 3.0 2.5 - 3.0 2.5 - 3.0 VVT - Intake Cam Phasing (ICP) ICP 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Dual Cam Phasing (DCP) DCP 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Discrete Variable Valve Lift (DVVL) on DOHC DVVLD 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Continuously Variable Valve Lift (CVVL) CV VL 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 Cylinder Deactivation on DOHC DEACD n.a. 0 - 0.5 0 - 0.5 0 - 0.5 Cylinder Deactivation on OHV DEACO n.a. 3.9 - 5.5 3.9 - 5.5 3.9 - 5.5 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Discrete Variable Valve Lift (DVVL) on OHV DVVLO 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6

Conversion to DOHC with DCP CDOHC 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 Stoichiometric Gasoline Direct Injection (GDI ) SGDI 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 Turbocharging and Downsizing TRBDS 4.5 - 5.2 2.1 - 2.2 2.1 - 2.2 2.1 - 2.2 Conversion to Diesel following CBRST DSLC 15.0 - 15.3 12.3 - 13.1 11.1 - 12.0 11.1 - 12.0 Conversion to Diesel following TRBDS DSLT 6.6 - 7.7 6.6 - 7.7 5.3 - 6.5 5.3 - 6.5 Electric Power Steering EPS 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 Improved Accessories IACC 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 12V Micro-Hybrid MHEV 1.0 - 2.9 1.2 - 2.9 3.4 - 4.0 3.4 - 4.0 Higher Voltage/Improved Alternator HVIA 0.2 - 0.9 0.2 - 0.9 0.2 - 0.6 0.2 - 0.6 Integrated Starter Generator (Belt/Crank) ISG 1.8 - 2.6 1.8 - 2.6 1.8 - 1.9 1.8 - 2.6 6-Speed Manual/Improved Internals 6MAN 0.5 0.5 0.5 0.5 Improved Auto. Trans. Controls/Externals IATC 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 Continuously Variable Transmission CVT 0.7 - 2.0 0.7 - 2.0 0.7 - 2.0 n.a. 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4

Dual Clutch or Automated Manual Transmission DCTAM 2.7 - 4.1 2.7 - 4.1 2.7 - 4.1 2.7 - 4.1 Material Substitution (1%) MS1 n.a. n.a. n.a. n.a. Material Substitution (2%) MS2 n.a. n.a. n.a. n.a. Material Substitution (5%) MS5 n.a. n.a. n.a. n.a. Low Rolling Resistance Tires ROLL n.a. n.a. n.a. n.a. Low Drag Brakes LDB n.a. n.a. n.a. n.a. Secondary Axle Disconnect SAX 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Aero Drag Reduction AERO 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY INCREMENTAL FUEL CONSUMPTION REDUCTION (-%) BY VEHICLE

TECHNOLOGY CLASS - PERFORMANCE CARSTable V-20. Technology Incremental Effe ctiveness Estimates, Light Trucks

Minivan Small Midsize Large

LT LT LT LT

V6 Inline 4 V6 V8

Low Friction Lubricants LUB 0.5 0.5 0.5 0.5 Engine Friction Reduction EFR 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Coupled Cam Phasing (CCP) on SOHC CCPS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Discrete Variable Valve Lift (DVVL) on SOHC DVVLS 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Cylinder Deactivation on SOHC DEACS 2.5 - 3.0 n.a. 2.5 - 3.0 2.5 - 3.0 VVT - Intake Cam Phasing (ICP) ICP 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 VVT - Dual Cam Phasing (DCP) DCP 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Discrete Variable Valve Lift (DVVL) on DOHC DVVLD 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 1.0 - 3.0 Continuously Variable Valve Lift (CVVL) CV VL 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 1.5 - 3.5 Cylinder Deactivation on DOHC DEACD 0 - 0.5 n.a. 0 - 0.5 0 - 0.5 Cylinder Deactivation on OHV DEACO 3.9 - 5.5 n.a. 3.9 - 5.5 3.9 - 5.5 VVT - Coupled Cam Phasing (CCP) on OHV CCPO 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Discrete Variable Valve Lift (DVVL) on OHV DVVLO 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6 0.5 - 2.6

Conversion to DOHC with DCP CDOHC 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 1.0 - 2.6 Stoichiometric Gasoline Direct Injection (GDI ) SGDI 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 1.9 - 2.9 Turbocharging and Downsizing TRBDS 2.1 - 2.2 4.5 - 5.2 2.1 - 2.2 2.1 - 2.2 Conversion to Diesel following CBRST DSLC 11.1 - 12.0 13.8 - 14.2 9.9 - 12.0 10.0 - 10.9 Conversion to Diesel following TRBDS DSLT 5.3 - 6.5 5.3 - 6.5 4.0 - 6.5 4.0 - 5.3 Electric Power Steering EPS 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 n.a. Improved Accessories IACC 1.0 - 2.0 1.0 - 2.0 n.a. n.a. 12V Micro-Hybrid MHEV 3.4 - 4.0 1.0 - 2.9 3.4 - 4.0 n.a. Higher Voltage/Improved Alternator HV IA 0.2 - 0.6 0.2 - 0.9 0.2 - 0.6 n.a. Integrated Starter Generator (Belt/Crank) ISG 5.7 - 6.5 5.7 - 6.5 5.7 - 6.5 n.a. 6-Speed Manual/Improved Internals 6MAN 0.5 0.5 0.5 0.5 Improved Auto. Trans. Controls/Externals IATC 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 1.5 - 2.5 Continuously Variable Transmission CVT 0.7 - 2.0 0.7 - 2.0 n.a. n.a. 6/7/8-Speed Auto. Trans with Improved Internals NAUTO 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4 1.4 - 3.4

Dual Clutch or Automated Manual Transmission DCTAM 2.7 - 4.1 2.7 - 4.1 2.7 - 4.1 2.7 - 4.1

Material Substitution (1%) MS1 n.a. n.a. 0.4 0.4

Material Substitution (2%) MS2 n.a. n.a. 0.4 0.4

Material Substitution (5%) MS5 n.a. n.a. 1.0 1.0 Low Rolling Resistance Tires ROLL 1.0 - 2.0 1.0 - 2.0 1.0 - 2.0 n.a. Low Drag Brakes LDB n.a. n.a. 0.5 - 1.0 0.5 - 1.0 Secondary Axle Disconnect SAX 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 Aero Drag Reduction AERO 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 2.0 - 3.0 Nominal Baseline Engine (For Cost Basis) VEHICLE TECHNOLOGY INCREMENTAL FUEL CONSUMPTION REDUCTION (-%) BY VEHICLE

TECHNOLOGY CLASS - LIGHT TRUCKSThe tables representing the Volpe model inpu t files for approximate net (accumulated) technology costs by vehicle subcla ss are presented below. The tables have been divided into passenger cars, performance passenger cars, and light trucks to make them easier to
read.V-151

Table V-21. Approximate Net (Acc umulated) Technology Costs, Passenger Cars

Subcompac t Compact Midsize Large
Ca r Ca r Car Car
Stoichiometric Gas Direct Injection (SGDI) 600 - 1,100 600 - 1,100 600 - 1,100 1,000 - 1,900 Turbocharge and Downsize (TRBDS) 2,000 - 2,600 2,000 - 2,600 2,000 - 2,600 1,900 - 2,700 Diesel Engine (DSLT/DSLC) 4,000 4,000 4,000 5,600 Dual Clutch Transmission (DCTAM) 500 500 600 600 Integrated Starter Generator Mild-hybrid (ISG) 2,400 - 2,500 2,800 3,000 - 3,100 3,200 - 3,300 APPROXIMATE RETAIL PRICE EQUIVALENT NET COSTS PER VEHICLE ($) BY VEHICLE CLASS TO KEY TECHNOLOGIES (Rounded to nearest $100)

Final Technology (As compared to baseline vehicle before any technologies are applied)

Table V-22. Approximate Net (Acc umulated) Technology Costs, Performance Passenger Cars

Performance Performance Performance Performance Subcompact Compact Midsize Large
C a r C a r C a r C a r Stoichiometric Gas Direct Injection (SGDI) 600 - 1,100 1,000 - 1,700 1,000 - 1,900 1,200 - 2,400 Turbocharge and Downsize (TRBDS) 2,000 - 2,600 1,900 - 2,700 1,900 - 2,700 2,600 - 3,700 Diesel Engine (DSLT/DSLC) 4,000 5,600 5,600 7,000 Dual Clutch Transmission (DCTAM) 600 600 600 600 Integrated Starter Generator Mild-hybrid (ISG) 2,500 - 2,700 2,900 3,000 - 3,100 3,300 APPROXIMATE RETAIL PRICE EQUIVALENT NET COSTS PER VEHICLE ($) BY VEHICLE CLASS TO KEY TECHNOLOGIES (Rounded to nearest $100)

Final Technology (As compared to baseline vehicle before any technologies are applied)

Table V-23. Approximate Net (Accumulat ed) Technology Costs, Light Trucks

Minivan Small Midsize Large
LT LT LT LT
Stoichiometric Gas Direct Injection (SGDI) 1,000 - 1,900 600 - 1,100 1,000 - 1,900 1,200 - 2,400 Turbocharge and Downsize (TRBDS) 1,900 - 2,700 2,000 - 2,600 1,900 - 2,700 2,600 - 3,700 Diesel Engine (DSLT/DSLC) 5,600 4,000 5,600 7,000 Dual Clutch Transmission (DCTAM) 600 600 600 600 Integrated Starter Generator Mild-hybrid (ISG) 3,200 - 3,300 2,800 - 2,900 3,200 n.a. APPROXIMATE RETAIL PRICE EQUIVALENT NET COSTS PER VEHICLE ($) BY VEHICLE CLASS TO KEY TECHNOLOGIES (Rounded to nearest $100)

Final Technology (As compared to baseline vehicle before any technologies are applied)V-152

The tables representing the Volpe model inpu t files for approximate net (accumulated) technology effectiveness values by vehicle subclass are presented be low. The tables have been divided into passenger cars, perfor mance passenger cars, and light tr ucks to make them easier to
read.

Table V-24. Approximate Net Techno logy Effectiveness, Passenger Cars

S u b compac t C ompact M id s i ze Large
Ca r Ca r Car Car
Stoichiometric Gas Direct Injection (SGDI) 4.8 - 13.1 4.8 - 13.1 4.8 - 13.1 7.2 - 14.1 Turbocharge and Downsize (TRBDS) 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 Diesel Engine (DSLT/DSLC) 21.2 - 25.9 21.2 - 25.9 20.2 - 24.9 20.2 - 24.9 Dual Clutch Transmission (DCTAM) 8.2 - 12.9 8.2 - 12.9 5.5 - 9.7 5.5 - 9.7 Integrated Starter Generator Mild-hybrid (ISG) 8.7 - 13.6 8.7 - 13.6 10.9 - 14.3 10.9 - 14.3 NET EFFECTIVENESS ESTIMATES FUEL CONSUMPTION REDUCTION PER VEHICLE (-%) BY VEHICLE CLASS TO KEY TECHNOLOGIES
Final Technology (As compared to baseline

vehicle before an y technolo g ies are a pp lied )

Table V-25. Approximate Net Technology Effectiveness, Performance Passenger Cars

Performance Performance Performance Performance Subcompact Compact Midsize Large
Ca r Ca r Ca r Ca r Stoichiometric Gas Direct Injection (SGDI) 4.8 - 13.1 7.2 - 14.1 7.2 - 14.1 7.2 - 14.1 Turbocharge and Downsize (TRBDS) 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 Diesel Engine (DSLT/DSLC) 21.2 - 25.9 21.2 - 25.9 20.2 - 24.9 20.2 - 24.9 Dual Clutch Transmission (DCTAM) 5.5 - 9.7 5.5 - 9.7 5.5 - 9.7 5.5 - 9.7 Integrated Starter Generator Mild-hybrid (ISG) 4.9 - 10.0 5.1 - 10.0 7.2 - 10.1 7.2 - 10.7 NET EFFECTIVENESS ESTIMATES FUEL CONSUMPTION REDUCTION PER VEHICLE (-%) BY VEHICLE CLASS TO KEY TECHNOLOGIES

Final Technology (As com pared to baseline vehicle before any technologies are applied)

Table V-26. Approximate Net Techno logy Effectiveness, Light Trucks

Minivan Small Midsize Large

LT LT LT LT Stoichiometric Gas Direct Injection (SGD I) 7.2 - 14.1 4.8 - 13.1 7.2 - 14.1 7.2 - 14.2 Turbocharge and Downsize (TRBDS) 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 11.2 - 17.4 Diesel Engine (DSLT/DSLC) 20.2 - 24.9 20.2 - 24.9 20.2 - 23.9 19.2 - 23.9 Dual Clutch Transmission (DCTAM) 5.5 - 9.7 5.5 - 9.7 5.5 - 9.7 5.5 - 9.7 Integrated Starter Generator Mild-hybrid (ISG) 10.9 - 14.3 8.7 - 13.6 10.0 - 12.6 n.a. NET EFFECTIVENESS ESTIMATES FUEL CO NSUMPTION REDUCTION PER VEHICLE (-%) BY VEHICLE CLASS TO KEY TECHNOLOGIES

Final Technology (As compared to baseline vehicle before any technologies are applied)V-153

C. Penetration of Tech nologies by Alternative

Tables V-27 shows the penetration of technologie s by alternative for passenger cars and Tables V-28 shows the penetration of technologie s for light trucks for the alternat ives. 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 altern atives get stricter.V-154

Table V-27
Penetration Rate of New Tec hnologies to Passenger Cars

Technology 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

Low Friction Lubricants 59% 59% 59% 59% 71% 71% 96% Engine Friction Reduction 5% 7% 11% 11% 15% 19% 33% VVT - Coupled Cam Phasing (CCP) on SOHC 9% 9% 10% 10% 10% 10% 10% Discrete Variable Valve Lift (DVVL) on SOHC 0% 0% 0% 0% 0% 0% 4% Cylinder Deactivation on SOHC 0% 0% 0% 0% 0% 0% 0% VVT - Intake Cam Phasing (ICP) 37% 35% 34% 34% 34% 33% 25% VVT - Dual Cam Phasing (DCP) 38% 41% 42% 42% 42% 43% 52% Discrete Variable Valve Lift (DVVL) on DOHC 0% 1% 4% 4% 4% 6% 12% Continuously Variable Valve Lift (CVVL) 0% 0% 0% 0% 0% 0% 1% Cylinder Deactivation on DOHC 3% 3% 3% 3% 3% 3% 1% Cylinder Deactivation on OHV 1% 1% 1% 1% 2% 2% 0% VVT - Coupled Cam Phasing (CCP) on OHV 4% 4% 4% 4% 4% 3% 4% Discrete Variable Valve Lift (DVVL) on OHV 0% 0% 0% 1% 1% 1% 2%

Conversion to DOHC with DCP 0% 0% 0% 0% 0% 0% 0% Stoichiometric Gasoline Direct Injection (GDI) 12% 12% 12% 13% 13% 15% 13%

Combustion Restart 0% 0% 0% 0% 0% 0% 11% Turbocharging and Downsizing 7% 7% 7% 9% 9% 9% 8% Exhaust Gas Recirculation (EGR) Bo ost 0% 0% 0% 0% 0% 0% 2% Conversion to Diesel following TRBDS 0% 0% 1% 1% 1% 2% 16% Conversion to Diesel following CBRST 0% 0% 0% 0% 0% 0% 0% 6-Speed Manual/Improved Internals 5% 5% 6% 6% 6% 6% 6% Improved Auto. Trans. Controls/Externals 6% 6% 6% 4% 4% 4% 9% Continuously Variable Transmission 11% 11% 11% 11% 11% 11% 11% 6/7/8-Speed Auto. Trans with Improved Internals 36% 36% 36% 34% 34% 34% 33%

Dual Clutch or Automated Manual Transmission 7% 7% 7% 12% 13% 13% 13% Electric Power Steering 36% 37% 37% 39% 42% 40% 45% Improved Accessories 36% 37% 37% 39% 39% 38% 44% 12V Micro-Hybrid 0% 1% 2% 1% 1% 3% 0% Higher Voltage/Improved Alternator 1% 1% 3% 5% 5% 8% 11% Integrated Starter Generator 0% 0% 0% 1% 1% 1% 4% Power Split Hybrid 5% 5% 5% 5% 5% 5% 12% 2-Mode Hybrid 0% 0% 0% 0% 0% 0% 0% Plug-in Hybrid 0% 0% 0% 0% 0% 0% 0% Material Substitution (1%) 0% 0% 0% 0% 0% 0% 0% Material Substitution (2%) 0% 0% 0% 0% 0% 0% 0% Material Substitution (5%) 0% 0% 0% 0% 0% 0% 0% Low Rolling Resistance Tires 32% 34% 34% 34% 34% 34% 53% Low Drag Brakes 4% 5% 5% 5% 6% 7% 7% Secondary Axle Disconnect – Unibody 0% 0% 0% 0% 0% 0% 0% Secondary Axle Disconnect - Ladder Frame 1% 1% 1% 1% 1% 1% 1% Aero Drag Reduction 11% 11% 11% 11% 12% 12% 27%V-155

Table V-28
Penetration Rate of New T echnologies to Light Trucks

Technology 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

Low Friction Lubricants 80% 80% 80% 80% 80% 80% 96% Engine Friction Reduction 25% 25% 26% 26% 25% 26% 34% VVT - Coupled Cam Phasing (CCP) on SOHC 6% 6% 6% 6% 6% 6% 6% Discrete Variable Valve Lift (DVVL) on SOHC 0% 0% 0% 0% 0% 0% 2% Cylinder Deactivation on SOHC 0% 0% 0% 0% 0% 0% 1% VVT - Intake Cam Phasing (ICP) 25% 25% 25% 25% 25% 25% 23% VVT - Dual Cam Phasing (DCP) 36% 36% 36% 36% 36% 36% 37% Discrete Variable Valve Lift (DVVL) on DOHC 0% 0% 1% 1% 0% 1% 4% Continuously Variable Valve Lift (CVVL) 0% 0% 2% 2% 0% 2% 0% Cylinder Deactivation on DOHC 1% 1% 1% 1% 1% 1% 6% Cylinder Deactivation on OHV 11% 11% 11% 11% 11% 10% 12% VVT - Coupled Cam Phasing (CCP) on OHV 13% 13% 13% 13% 13% 13% 17% Discrete Variable Valve Lift (DVVL) on OHV 2% 2% 2% 2% 2% 2% 2%

Conversion to DOHC with DCP 0% 0% 0% 0% 0% 0% 0% Stoichiometric Gasoline Direct Injection (GDI) 10% 10% 12% 12% 10% 10% 9%

Combustion Restart 1% 1% 1% 1% 1% 1% 19% Turbocharging and Downsizing 5% 5% 7% 7% 5% 7% 6% Exhaust Gas Recirculation (EGR) Bo ost 0% 0% 0% 0% 0% 0% 0% Conversion to Diesel following TRBDS 1% 1% 1% 1% 1% 2% 8% Conversion to Diesel following CBRST 3% 3% 3% 3% 3% 3% 3% 6-Speed Manual/Improved Internals 0% 0% 0% 0% 0% 0% 0% Improved Auto. Trans. Controls/Externals 14% 14% 14% 14% 14% 15% 15% Continuously Variable Transmission 3% 3% 3% 3% 3% 3% 3% 6/7/8-Speed Auto. Trans with Improved Internals 39% 39% 39% 39% 39% 39% 38%

Dual Clutch or Automated Manual Transmission 10% 10% 10% 10% 10% 10% 12% Electric Power Steering 34% 34% 34% 34% 34% 34% 33% Improved Accessories 19% 19% 19% 19% 19% 19% 22% 12V Micro-Hybrid 2% 2% 2% 2% 2% 2% 0% Higher Voltage/Improved Alternator 5% 5% 5% 5% 5% 5% 10% Integrated Starter Generator 1% 1% 1% 1% 1% 1% 7% Power Split Hybrid 1% 1% 1% 1% 1% 1% 2% 2-Mode Hybrid 1% 1% 1% 1% 1% 1% 1% Plug-in Hybrid 0% 0% 0% 0% 0% 0% 0% Material Substitution (1%) 3% 3% 3% 3% 3% 3% 6% Material Substitution (2%) 1% 1% 1% 1% 1% 1% 2% Material Substitution (5%) 0% 0% 1% 1% 0% 1% 2% Low Rolling Resistance Tires 39% 39% 39% 39% 39% 41% 49% Low Drag Brakes 17% 17 % 17% 17% 17% 17% 28% Secondary Axle Disconnect - Unibody 0% 0% 0% 0% 0% 0% 0% Secondary Axle Disconnect - Ladder Frame 25% 25% 25% 25% 25% 25% 27% Aero Drag Reduction 18% 18% 18% 18% 18% 18% 27%VI-1



### VI. M ANUFACTURER 

### S PECIFIC 

### CAFE C APABILITIES

Table VI-1 shows the CAFE product plans fo r each of the manufacturers, based on the manufacturer’s plans without taking into account any alternative or dual fuel vehicle attributes.

Table VI-2 shows the ADJUSTED BASELINE . Note that when we do cost and benefit analyses, we use the ADJUSTED BASELINE throughout the analysis. The adjusted baseline is essentially the higher of the manufacturer’s plan s or the MY 2010 fuel economy standard. The adjusted baseline assumes for the analysis that each manufacturer, below the MY 2010 standard applicable to that manufacturer , (except Ferrari, Maserati, Da imler, Porsche and Volkswagen) would apply technology to achieve the MY 2010 standard. Those mpg levels of those manufacturers with product plan s above the MY 2010 standard, or above their required reform level standard in any model year, are retained fo r the adjusted baseline. Our rationale for this adjustment of the baseline is that the costs a nd 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 tec hnologies to the manufacturers’ plans and increase them to the adjusted baseline. The costs of these technologie s are estimated, but they are not considered part
of this rule. We then estimate the costs and be nefits of going from the adjusted baseline to the
level of the alternatives. 208

The required standard levels are shown in Table VI-3 for passenge r cars and for light trucks. Table VI-4 provides the estimated ac hieved levels for passenger cars and light trucks. All of the analyses compared the estimated achieved levels versus the adjusted baseline. Table VI-5 for passenger cars and Table VI-6 for light trucks sh ows what we believe th e manufacturers’ fuel economy could be for “meeting” the alternative levels analyzed in this anal ysis. They include in some cases manufacturers’ plans at levels higher than the altern ative standards would require.
Note that not all manufacturers are assumed to attempt to “meet” the alternatives. We assume that Ferrari, Maserati, Daimler, Porsche and Vo lkswagen would not meet these levels because, for them, the cost of meeting these levels is mo re than the cost of pa ying penalties. These manufacturers have shown, in the past, the willi ngness to pay penalties ra ther than spend more money to improve the fuel ec onomy of their products.

The agency has performed an analysis of how manufacturers could respond to changes in the proposed CAFE levels. The “Technology Applicati on Analysis” (or the “Volpe Analysis”) uses a technology application algorithm to systemati cally apply consistent cost and performance assumptions to the entire i ndustry, as well as consistent assumptions regarding economic decision-making by manufacturers. The resultin g 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 anal ysis shows the economic im pact of the standards
in terms of increases in new ve hicle prices on a manufacturer-wid e, industry-wide, and average

208 Some manufacturer’s plans are above the level of the stan dard 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 le vel for each manufacturer may be slightly higher than the
level of the standard and costs and benefits are estimated to that level.VI-2

per-vehicle basis. Based on these estimates and corresponding estimates of net economic and other benefits, the agency is able to consider alternatives that are ec onomically practicable and technologically feasible.

We note that the Volpe model has been updated and refined with re spect to its representation of some fuel-saving technologies, but the model remains fundamentally unchanged. The model has been peer reviewed. The model documentation, in cluding 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. 209

Our analyses of the potential e ffects of alternative CAFE standards were founded on two major elements: (1) projections of the technical char acteristics and sales vo lumes 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 utili zed in response to alternative
CAFE standards.

209 See Docket Nos. NHTSA-20005-22223-3, 4, 5.VI-3

Table VI-1

Manufacturers Production Plans – MY 2011

Estimated mpg

Manufacturer Passenger Cars Light Trucks

BMW 27.0 23.0 Chrysler 28.2 23.1

Daimler 25.2 20.6

Ferrari 16.2 N.A.

Ford 29.3 22.5

General Motors 30.3 21.4

Honda 32.3 25.2 Hyundai 31.7 26.0

Maserati 18.2 N.A.

Mitsubishi 29.3 26.7

Nissan 31.3 21.4

Porsche 27.2 20.0

Subaru 28.6 28.6

Suzuki 28.7 24.0

Tata 24.7 23.9 Toyota 33.2 22.7 Volkswagen 28.5 20.1 Total/Average 30.4 22.6VI-4

Table VI-2

Adjusted Baseline – MY 2011

Estimated mpg

Manufacturer Passenger Cars Light Trucks

BMW 27.5 23.9 Chrysler 28.2 23.3

Daimler 25.9 20.6

Ferrari 16.2 N.A.

Ford 29.3 22.6

General Motors 30.3 22.2

Honda 32.3 25.2 Hyundai 31.7 26.0

Maserati 18.2 N.A.

Mitsubishi 29.3 26.7

Nissan 31.3 21.8

Porsche 27.5 20.0

Subaru 28.6 28.6

Suzuki 28.7 24.0

Tata 26.0 24.9 Toyota 33.2 23.1 Volkswagen 28.5 20.1 Total/Average 30.5 23.0VI-5

Table VI-3

Estimated Required Levels by Final Rule MY 2011

Estimated mpg

Manufacturer Passenger Cars Light Trucks

BMW 30.2 25.7 Chrysler 28.6 24.2

Daimler 28.9 24.5

Ferrari 30.7 NA

Ford 30.1 23.6

General Motors 30.0 23.3

Honda 30.6 25.4 Hyundai 30.3 25.3

Maserati 27.5 NA

Mitsubishi 30.9 26.7

Nissan 30.5 24.0

Porsche 31.2 25.5

Subaru 30.9 26.6

Suzuki 31.0 26.4

Tata 27.5 26.1 Toyota 30.6 24.8 Volkswagen 30.9 24.9 Total/Average 30.2 24.1VI-6

Table VI-4

Estimated Achievable Levels – MY 2011

Estimated mpg

Manufacturer Passenger Cars Light Trucks

BMW 27.7 23.9 Chrysler 28.6 24.2

Daimler 25.9 20.6

Ferrari 16.2 NA

Ford 30.1 22.6

General Motors 30.3 22.2

Honda 32.3 25.5 Hyundai 31.7 26.0

Maserati 18.2 NA

Mitsubishi 31.2 26.7

Nissan 31.3 21.8

Porsche 28.2 20.0

Subaru 30.0 28.6

Suzuki 29.5 24.0

Tata 26.1 25.9 Toyota 33.2 23.1 Volkswagen 29.0 20.1 Total/Average 30.7 23.2VI-7

Table VI-5

Estimated Achievable Fuel Economy Levels

By Alternative – MY 2011

Passenger Cars

(mpg)

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 27.7 27.7 27.7 27.7 27.7 27.7 27.9
Chrysler 28.4 28.6 28.9 29.5 29.5 29.8 31.5

Daimler 25.9 25.9 25.9 25.9 25.9 25.9 25.9

Ferrari 16.2 16.2 16.2 16.2 16.2 16.2 16.2

Ford 29.9 30.1 30.4 30.5 30.5 30.5 31.2
General

Motors 30.3 30.3 30.3 30.6 31.0 31.3 32.0

Honda 32.3 32.3 32.3 32.3 32.3 32.3 36.0
Hyundai 31.7 31.7 31.7 31.7 31.7 31.7 35.4

Maserati 18.2 18.2 18.2 18.2 18.2 18.2 18.2

Mitsubishi 30.6 31.2 31.2 31.2 31.2 31.2 31.9

Nissan 31.3 31.3 31.3 31.3 31.6 31.9 32.1

Porsche 28.2 28.2 28.2 28.2 28.2 28.2 28.4

Subaru 30.0 30.0 30.0 30.0 30.0 30.0 30.5

Suzuki 29.5 29.5 29.5 29.5 29.5 29.5 29.7

Tata 26.1 26.1 26.1 26.1 26.1 26.1 27.2

Toyota 33.2 33.2 33.2 33.2 33.2 33.2 33.9
Volkswagen 29.0 29.0 29.0 29.0 29.0 29.0 29.1

Total/Average 30.7 30.7 30.8 31.0 31.0 31.2 32.4VI-8

Table VI-6

Estimated Achievable Fuel Economy Levels

By Alternative – MY 2011

Light Trucks

(mpg)

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 23.9 23.9 23.9 23.9 23.9 23.9 23.9
Chrysler 24.2 24.2 24.3 24.3 24.2 24.5 25.4

Daimler 20.6 20.6 20.6 20.6 20.6 20.6 20.6

Ferrari NA NA NA NA NA NA NA

Ford 22.6 22.6 22.6 22.6 22.6 22.6 22.6
General

Motors 22.2 22.2 22.2 22.2 22.2 22.2 22.6

Honda 25.5 25.5 25.5 25.5 25.5 25.6 28.0
Hyundai 26.0 26.0 26.0 26.0 26.0 26.0 28.2

Maserati NA NA NA NA NA NA NA

Mitsubishi 26.7 26.7 27.2 27.2 26.7 27.2 32.1

Nissan 21.8 21.8 21.8 21.8 21.8 21.8 21.9

Porsche 20.0 20.0 20.0 20.0 20.0 20.0 20.0

Subaru 28.6 28.6 28.6 28.6 28.6 28.6 28.7

Suzuki 24.0 24.0 24.0 24.0 24.0 24.0 24.0

Tata 25.9 25.9 25.9 25.9 25.9 25.9 27.8

Toyota 23.1 23.1 23.1 23.1 23.1 23.1 23.2
Volkswagen 20.1 20.1 20.1 20.1 20.1 20.1 20.1

Total/Average 23.2 23.2 23.2 23.2 23.2 23.2 23.7VII-1



### VII. COST IMPACTS

Technology Costs Table V-1 provides the technology cost estimates us ed in this analysis. These are meant to represent consumer costs for high-volume produc tion of these technol ogies after sufficient experience with their applicati on have resulted in all “learn ing 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 cas e 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 “learn ing curve” will result in a reduction in the variable cost of the product. The variable cost s are marked up by a factor of 1.5 to take into account fixed costs of R&D, burden, manufacture r’s profits, and dealer’s profits. The final
results are shown in Table V1.

The variable costs are incremental costs in materi al, labor, and variable bu rden 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 incrementa l cost, calculated as the cost of applying a 5- speed transmission less the cost of applying the previously applied 4-speed automatic
transmission.

Manufacturers’ actual costs for applying these tec hnologies to specific vehi cle models are likely to include significant additional outlays for accompanying design or engineering changes to each model, development and testing of prototype versions, recalibrat ing engine operating parameters, and integrating the technology with other attributes of the vehicle. Manuf acturers may also incur additional corporate overhead, marketing, or distri bution and selling expenses as a consequence of their efforts to improve the fuel economy of individual vehicle m odels and their overall product lines.

In order to account for these additional costs, th e 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 consum er cost. This estimate was developed by Argonne National Laboratory in a re cent review of vehicle manufactur ers’ indirect costs. The Argonne study was specifically intended to improve the accuracy of future cost estimates for production of vehicles that achie ve high fuel economy by employing many of the same advanced technologies considered in the agency’s analysis. 210 Thus, its recommendation that a multiplier of 1.5 be applied to direct manufacturing costs to reflect manufacturers’ in creased indirect costs for deploying advanced fuel economy technologie s appears to be appropriate for use in the agency’s current analysis. Historically, NHTSA has used almost the exact same multiplier, a multiplier of 1.51 211 , as the markup from variable cost s or direct manufacturing costs to

210 Vyas, Anant, Dan Santini, and Roy Cuenca, Comparison of Indirect Cost Multipliers for Vehicle Manufacturing , Center for Transportation Research, Argonne National Laboratory, April 2000.

211 Spinney, Bruce C., CPA, NHTSA “Advanced Air Bag System Cost Weight and Leadtime Analysis Summary Report” Docket No. 2007-27453-10.VII-2

consumer costs. This markup takes into account fixed costs, burden, manufacturer’s profit, and dealers profit. NHTSA’s methodology for deve loping 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 ma nufacturers 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 w ould represent an additional cost of achieving the required improvements in fuel economy, and thus of manufacturers’ comp liance with stricter
CAFE standards. While exact do llar values of these attributes to buyers are extremely difficult to infer from vehicle purchase prices, it is nevert heless clear that changes in these attributes can affect the utility that vehicles pr ovide to their owners, and thus their value to potential buyers.

The agency has approached this potential pr oblem by developing cost estimates for fuel economy-improving technologies that include any additional manuf acturing costs that would be necessary to maintain the performance, comfort, capacity, or safety of a ny vehicle to which those technologies are applied. Theoretically, opportu nity costs could also include any foregone opportunities to enhance these products for consumer s. However, estimating values for foregone opportunities is an even tougher ta sk. So, the agency followed th e precedent established by NAS in its 2002 analysis of the costs and benef its of improving fuel economy by raising CAFE
standards. 212 The NAS study estimated “constant pe rformance and utility” costs for fuel economy technologies, and the agency has used th ese as the basis for developing the technology costs it employed in analyzing manufacturer’s cost s for complying with alternative standards.

NHTSA fully acknowledges the difficulty of estim ating technology costs that include costs for the accompanying changes in vehicle design that are necessary to maintain performance, capacity, and utility. However, the agency be lieves its cost estimates for fuel economy technologies are generally sufficient to prevent significant reductions in consumer welfare.

The technology application algorith m implemented with the Volpe model was used as the basis for estimating costs for the fleet. 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 th at 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 be nefits, are considered part of the costs and benefits of complying with pr eviously issued rules.

212 National Academy of Sciences, Costs and Effectiveness of Increasi ng Corporate Average Fuel Economy
Standards , 2002.VII-3

Tables VII-4a through 4n for passenger cars a nd 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 re sulted in a fuel economy level of 22.2 mpg during each model year, the cost represents the cumu lative cost of technologies necessary to bring that ma nufacturer’s fleet average up to the le vels of the alternative. The costs
for several manufacturers are the fines that these manufacturers woul d have to pay on an average
vehicle basis. We assume that the costs of fi nes 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 sec ond part of these tables, since th ese are transfer payments and not technology costs.VII-4

Table VII-1
Estimated Incremental Costs or Fines over Manufacturer’s Plans To get to Adjusted Baseline – MY 2011 Average Cost per Vehicle (2007$)

Manufacturer Passenger Cars Light Trucks

BMW (64.6) (215.8) Chrysler - (19.0) Daimler (300.6) (137.5) Ferrari (621.5)

Ford - (67.0) General Motors - (529.8)

Honda - - Hyundai - - Maserati (511.5)

Mitsubishi - -

Nissan - (269.8) Porsche (80.7) (214.5)

Subaru - - Suzuki - (88.0)

Tata (1,112.9) (355.0) Toyota - (137.4) Volkswagen - (181.5) Total/Average (8.8) (205.1)VII-5

Table VII-2 Estimated Incremental Costs or Fines over Adjusted Baseline Average Cost per Vehicle (2007$) MY 2011 Passenger Cars

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 200 217 233 255 272 288 536
Chrysler 16 44 140 425 425 642 3,440

Daimler 66 77 94 110 127 143 341

Ferrari 160 176 193 215 237 253 479

Ford 70 119 391 633 655 666 1,661
General

Motors 0 0 0 29 118 396 1,727

Honda 0 0 0 0 0 0 1,427
Hyundai 0 0 0 0 0 0 2,260

Maserati 0 0 11 28 39 55 231

Mitsubishi 280 787 787 872 894 910 1,767

Nissan 0 0 0 0 47 265 847

Porsche 441 458 474 496 518 535 763

Subaru 343 360 376 398 420 437 810

Suzuki 233 250 261 283 305 321 572

Tata 0 0 11 28 44 55 231

Toyota 0 0 0 0 0 0 388
Volkswagen 186 203 219 241 258 274 516

Total/Average 40 64 120 193 220 310 1,445VII-6

Table VII-3 Estimated Incremental Costs or Fines over Adjusted Baseline Average Cost per Vehicle (2007$) MY 2011 Light Trucks

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 72 72 77 77 72 83 380
Chrysler 473 473 690 690 473 1,079 2,919

Daimler 77 77 83 83 77 88 358

Ferrari 0 0 0 0 0 0 0

Ford 33 33 39 39 33 44 292
General

Motors 44 44 50 50 44 55 739

Honda 35 35 35 35 35 42 2,912
Hyundai 0 0 0 0 0 0 2,602

Maserati 0 0 0 0 0 0 0

Mitsubishi 0 0 54 54 0 54 3,915

Nissan 44 44 50 50 44 55 314

Porsche 88 88 94 94 88 99 391

Subaru 0 0 0 0 0 0 225

Suzuki 44 44 50 50 44 55 369

Tata 2,274 2,274 2,279 2,279 2,274 2,285 7,220

Toyota 55 55 61 61 55 66 336
Volkswagen 83 83 88 88 83 94 374

Total/Average 126 126 169 169 126 242 1,177VII-7

Table VII-4 Estimated Incremental Costs or Fines over Adjusted Baseline Total Incremental Costs in Millions (2007$) MY 2011 Passenger Cars

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 68 74 79 87 93 98 183
Chrysler 11 31 99 300 300 454 2,433

Daimler 3 4 5 6 7 8 18

Ferrari 0 0 0 0 0 0 1

Ford 114 192 632 1,022 1,058 1,076 2,683
General Motors 0 0 0 49 201 674 2,936

Honda 0 0 0 0 0 0 1,783
Hyundai 0 0 0 0 0 0 1,480

Maserati 0 0 0 0 0 0 1

Mitsubishi 59 165 165 183 188 191 371

Nissan 0 0 0 0 37 210 669

Porsche 6 6 6 7 7 7 10

Subaru 32 33 35 37 39 40 75

Suzuki 24 26 27 29 32 33 59

Tata 0 0 0 1 2 2 8

Toyota 0 0 0 0 0 0 545
Volkswagen 58 63 68 75 80 85 160

Total/Average 375 595 1,117 1,796 2,042 2,878 13,415VII-8

Table VII-5 Estimated Incremental Costs or Fines over Adjusted Baseline Total Incremental Costs in Millions (2007$) MY 2011 Light Trucks

Manufacturer 25%
Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC =

TB Tech

Ex.

BMW 7 7 7 7 7 8 37
Chrysler 575 575 839 839 575 1,312 3,549

Daimler 2 2 2 2 2 2 8

Ferrari 0 0 0 0 0 0 0

Ford 38 38 44 44 38 50 333
General Motors 81 81 91 91 81 101 1,363

Honda 16 16 16 16 16 20 1,367
Hyundai 0 0 0 0 0 0 576

Maserati 0 0 0 0 0 0 0

Mitsubishi 0 0 1 1 0 1 66

Nissan 21 21 24 24 21 26 150

Porsche 2 2 2 2 2 3 10

Subaru 0 0 0 0 0 0 29

Suzuki 1 1 1 1 1 1 8

Tata 58 58 58 58 58 59 185

Toyota 60 60 66 66 60 72 367
Volkswagen 4 4 4 4 4 4 17

Total/Average 865 865 1,157 1,157 865 1,660 8,065VII-9

Financial Impacts of Raising CAFE Standards As has been widely reported in the public domain throughout this rulemaking, and as shown in public comments, the national and global economies are in crisis. Even before those recent developments, the automobile ma nufacturers were already faci ng substantial difficulties. Together, these problems have made NHTSA’s economic practicability analysis particularly important and challenging in this rulemaking.

Automobile sales have dropped si gnificantly. U.S. motor vehicl e sales in 2008 were 18 percent below 2007 levels. January 2009 industry sales were 37 percent lower than in January 2008. 213 The sales of every major manufacturer declined. Vehicle manufacturers have not been able to raise prices to offset declining unit sales. 214

The financial state of the major U.S. automotive manufacturers is particularly difficult.. General
Motors’ 2008 U.S. vehicle sales were down 23 percent, and January 2009 sales were down 51
percent. 215 GM last earned an accounting profit in 2004, and has lost a cumulative $72 billion between 2005 and the third quarter of 2008. 216 GM has a negative net worth of $60 billion, and consumed more than $3.5 billion in cash in th e third quarter. GM is largely unable to borrow additional funds in capital markets, and must rely on a dwindling pool of cash to fund any further operating losses and capital investments.

Ford Motor Company’s 2008 sa les declined 20 percent. 217 The firm has lost nearly $30 billion since 2006. The firm has a negative net worth of $2 billion, and consumed some $5.5 billion in cash in the fourth quarter of 2008. 218 Ford is also largely unable to borrow additional funds in capital markets, and must also rely on a dwi ndling pool of cash to fund any further operating losses and capital investments.

Chrysler is closely held, and consequently does not publish financial statements. However, Chrysler’s 2008 unit sales were 30 percent below last year’s sa les, and January 2009 sales were off 55 percent. 219 In a report to submitted to the Senate Banking Committee in December 2008, Chrysler indicated that, if the Federal Governme nt provided $13 billion in financing, Chrysler

213 Ward’s Automotive, “Ward’s U.S. Light Vehicl e Sales Summary,” December 2008. Available at: http://wardsauto.com/keydata/USSa lesSummary0812 .xls / (Last accessed February 6, 2008).

214 Commerce Department data indicates no apparent change in nominal prices of new vehicle sales over the past few years.

215 General Motors Corp, monthly sales repo rt for December 2008. Available at: http://www.gm.com/corporate/investor_i nformation/sales_prod/hist_sales.jsp (last accessed February 6, 2009).

216 General Motors Corp. annual report for 2007, quarterly earnings announcement for the third quarter of 2008.
Available at http://www.gm.com/corporate/i nvestor_information/ear nings/index.jsp (last accessed November 12, 2008).

217 Ford Motor Company, Fourth qua rter 2008 financial results. Ava ilable at: http://www.ford.com/aboutford/investor-relations/c ompany-reports/financia l-results (last accessed February 6, 2009).

218 Ford Motor Company, Annual Report 2007, p. 121 and fourth quarter 2008 earning release, Slide 26..

219 Ward’s Automotive, op. cit.VII-10

expected to end 2009 with so me $6.7 billion in net cash. 220 However, absent federal intervention, it is not clear that Chrysler would be able to survive 2009 in one piece.

As the figures set forth above demonstrate, th e automobile industry is already experiencing substantial economic hardship, even in the abse nce of new fuel economy standards. All three firms have announced a steady stream of plan t closings, layoffs, and employment of new employees at reduced wages.

NHTSA believes these hardships have much to do with the condition of the national economy and perhaps the price of gasolin e, and little, if anything, to do with the stringency of CAFE standards for the current or recent model years. We believe that given the scale of the recent decline in industry sales, and the restrictiveness of private credit markets, that near-term developments will be compelled by the industry’s immediate financial situation, rather than by the long-term financial conse quences of this rulemaking.

Market forces are already requiri ng manufacturers to improve the fu el economy of their vehicles, as shown both by changes in product plan s reported to NHTSA, and by automaker announcements in recent weeks. The improvements in fleet fuel economy required by this rule are consistent with the pressure i nduced by changing consumer preferences.

The various compliance flexibility mechanisms permitted by EISA, including flexible and alternative fuel vehicles, banking, averaging, an d trading of fuel economy credits will also reduce compliance costs to some degree. By statute, NHTSA is not permitted to consider the benefits of flexibility mechanisms in assessing the costs and benefits of the rule.

On the other hand, the agency is mindful th at CAFE standards do affect the relative competitiveness of different vehicle manufacturers, and recognizes that standards more stringent than those promulgated here could have a more detrimental effect.

However, the core of the problem for the agency is to determine what new standards might be economically practicable within the MY 2011 time frame, given th e state of both the domestic
and the international auto industries. Th e complexity of an economic practicability determination has been materially increased by th e decision of GM and Chrysler to seek, and the U.S. Government to provide, substantial fina ncial assistance. Congr ess has appropriated $7.5 billion (to support a maximum of $25 billion in loans under Section 136 of EISA to support the development of advanced technology vehicl es and components in the United States. 221 DOE reports that 75 requests for funding, totaling some $38 billion have been received by the deadline date, of which 23 requests were deemed “substantia lly complete,” and hence eligible for further consideration among the initia l tranche of projects.

220 Robert Nardelli, “Chrysler’s Plan for Short-Term and Long-Term Viability,” submitted to Senate Committee on Banking, Housing, and Urban Affairs, December 2, 2008. Available at: http://banking.senate. gov/public/files/ChryslerUSSenateViabilityPlan .pdf (last accessed Fe bruary 6, 2009).

221221 The authorizing language for this provision is in Sec tion 136 of EISA. This language is amended and funds are appropriated in the Emergency Economic Stabilization Act of 2008 (H.R. 1424, Pub.L. 110-343). See also the DOE Advanced Technology Vehicle Manufacturing Loan Pr ogram website: http://www.atvmloan.energy.gov/ (last accessed February 6, 2009).VII-11

The Treasury Department has also advanced su bstantial funding to GM , Chrysler and GMAC under the Troubled Asset Relief Program (TARP). (Ford elected not to accept public funding under the TARP). GM received a loan of $13.4 billion, while Chrysler received $4 billion. 222 GM and Chrysler have also submitted restruct uring plans to the Treasury Department in February 2009 requesting additi onal Federal assistance to “ac hieve and sustain long-term viability” while “comply[ing] with applicable Federal fuel efficiency and emission requirements.” Since this rule had not been promulgated at the time the report was submitted, GM and Chrysler were left with a degree of doubt about exactly what CAFE standards would apply to MYs 2011 and thereafter.

Given the foregoing, therefore, the agency has decided that in this exceptional situation, economic practicability must be determined based on whether the expenditures needed to achieve compliance with the final MY 2011 standard s are “within the financ ial capability of the industry, but not so stringent as to threaten substantial economic hardship for the industry,” no matter who contributes the funds. This is an oper ational definition of a standard set using costbenefit analysis. We have attempted to set th e MY 2011 CAFE standards so that they are both technologically and economically feasible wh ile providing the maximum national public social benefit. In principle, most vehicles meeting th e standard will provide social benefits to the public at large and private benefits to automob ile owners greater than their extra cost.

One of the primary ways in which the agency seek s to ensure that its standards are within the financial capability of the industry is to attempt to ensure that manufacturers have sufficient lead time to modify their manufacturing plans to comply with the final standards in the model years covered by them. Employing appropriate assumptions about lead time in our analysis helps to avoid applying technologies before they are ready to be applie d, or when their benefits are insufficient to justify their costs. It also helps avoid basing standards on the assumption that technologies could be applied more rapidly than practically achievable by manufacturers. NHTSA considers these matters in its analysis of issues including refresh and redesign schedules, phase-in caps, and learning rates.

A number of manufacturers commen ted that the proposed standard s were too stringent in the early years and were therefore not economically practicable. In reevaluating the range of fuelsaving technologies expected to be available in MY 2011, th e agency has developed more
realistic estimates of the set of technologies available, the extent to which these technologies are most likely to be applied e ither at a vehicle freshening or redesign, and the limits ( i.e. , caps) that should be applied to the rates at which these technologies can be phased in. NHTSA believes the resultant MY 2011 standards, which also reflect all other inputs to NHTSA analysis, are not inappropriately “front loaded,” particularly given that th ey cover only one model year.

NHTSA further considers the sale s and employment impacts of th e final standards on individual manufacturers as part of its efforts to determine whether the standards are economically practicable. The sales analysis looks at a purchasing decision from the eyes of a knowledgeable and rational consumer, comparing the estimated cost increase versus the payback in fuel savings

222 U.S. Department of the Treasury, “Indicative Summary of Terms for Secured Term Loan Facility,” December 19, 2008, for Chrsyler and GM. Available at http://www.treasury. gov/press/releases/hp1333.htm (last accessed February 6, 2009).VII-12

over 5 years (the average new vehicle loan) for e ach manufacturer. This relationship depends on the cost-effectiveness of technologies availabl e to each manufacturer. Overall, based on a 7 percent discount rate for future fuel savings, wh ile the sales and employment impacts estimated from the final standards are high er than those estimated in the NPRM, they are still relatively small compared to the impacts estimated from th e higher alternatives discussed above, such as the standards set such that total costs equal total benefits.

The agency does not have the capability to predic t 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 agency asked for comments to provide us with information abou t the ability of manufacturers to provide the capital investment
needs for the various alternatives. Ho wever, no responses were provided.

The Impact of Higher Prices on Sales

Higher fuel economy standards are expected to in crease the price of pass enger cars and light trucks. The potential impact ofhigher 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. 223, 224, 225 Thus, every one percent increase in the price of the vehicle woul d 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 addi ng technologies that improve fuel economy. If consumers do not value improved fuel economy at al l, and consider nothi ng but the increase in price in their purchase decisions, then the estimat ed impact on sales from price elasticity could be applied directly. However, we believe th at consumers do value improved fuel economy, because they reduce the operating cost of the vehicl es. We also believe that consumers consider
other factors that affect their costs and ha ve included these in the analysis.

One issue that significantly affects this sales analysis is: How much of the retail price increase needed to cover the fuel economy technology inve stments will manufacturers be able to pass on to consumers? The estimates reported above assu me that manufacturers w ill be able to pass all of their costs to improve fuel economy on to c onsumers. However, the ability of manufacturers to pass the compliance costs on to consumers will depend upon how consumers value the fuel economy improvements. Consumer valuation of fuel economy improvements often depends upon the price of gasoline, which has recently been ve ry volatile. To the extent that we have accurately predicted the price of gasoline and consumers reactions , and manufacturers can pass on all of the costs to consumers, then the sales and employment impact analyses are reasonable. If manufacturers only increase re tail prices to the extent th at consumers value these fuel economy improvements, then there would be no impact on sales.

223 Kleit, A.N. (1990). “The Effect of Annual Changes in Auto mobile Fuel Economy Standards.” Journal of Regulatory

Economics , vol. 2, pp 151-172.

224 Bordley, R. (1994). “An Overlapping Choi ce Set Model of Automotive Price Elasticities,” Transportation Research B , vol 28B, no 6, pp 401-408.

225 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.VII-13

Sales losses are predicted to occur only if cons umers fail to value fuel economy improvements at least as much as they pay in higher prices. Our analysis indicates that du ring the first 5 years, on average initial purchasers will not yet recoup their added invest ment and this leads to our prediction of sales losses. If manufacturers are unable to ra ise prices beyond the level of consumer's valuation of fuel savings, then manuf acturer's profit levels w ould fall but there would be no impact on sales. Likewise, if fuel pri ces rise beyond levels us ed in this analysis, consumer's valuation of improved fuel economy c ould increase to match or exceed their initial investment, resulting in no impact or even an increase in sales levels.

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. 226 The present values of these savings were calculated using a 7 percent discount
rate for those alternatives that were based on a 7 percent discount rate and using a 3 percent
discount rate for the one alternative based on a 3 percent discount rate. 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 year s and discounted back to a present value.

The agency believes that consumers may consider several other factors over the 5 year horizon when contemplating the purchase of a new vehicl e. The agency added these factors into the calculation to represent how an increase in technology costs mi ght affect consumers’ buying
considerations.

First, consumers might consider the sales taxes th ey have to pay at the time of purchasing the vehicle. We took sales taxes in 2007 by stat e 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 comprehensiv e (e.g., theft) car insurance. According to the
National Association of Insurance Commissione rs (NAIC) the national average premium for collision + comprehensive insurance in 2000 wa s $389 while the average new car transaction price was $20,600. If we assume that this pr emium 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. Discounti ng that stream of insurance costs back to present value indicates that the present value of the component of insuran ce costs that vary with vehicle price is equal to 8.7 per cent of the vehicle’s price at a 3 percent discount rate and 8.0 percent of the vehicle’s price at a 7 percent discount rate.

Third, we considered that 70 percent of new vehi cle purchasers take out loans to finance their purchase. The average new vehicle loan is for 5 years at a 6 percent rate 227 . At these terms the average person taking a loan will pay 16 percent mo re for their vehicle over the 5 years than a

226 National average financing terms for automobile loans ar e available from the Board of Governors of the Federal Reserve System G.19 “Consumer Finance” release. See: http://www.federalre serve.gov/releases/g19/

227 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 percentVII-14

consumer paying cash for the vehicle at the time of purchase 228 . Discounting the additional 3.2 percent (16 percent / 5 years) per year over the 5 years us ing a 3 percent mid-year discount

rate 229 results in a discounted present value of 14.87 percent higher for those taking a loan, and at a 7 percent discount rate result s in a 13.58 percent higher for thos e 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 the consumer discounted at a 3 percent discount rate and 9.5 percent more than the retail price for loans the consumer discounted at a 7 percent discount rate.

Fourth, we considered the residu al 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 look ed at 138 model year 2002 vehicles to compare their original MSRP values (based on www.nadagui des.com) to their current trade-in values (5 years later in 2007 based on www.edmunds.com). Th e sales weighted average residual value for this group of vehicles was 37.5 percent. Discoun ting the residual value b ack 5 years using a 3 percent discount rate (37.5 pe rcent * .8755) gives an effectiv e residual value at new of 32.8 percent. Discounting the residual value back 5 years using a 7 percen t discount rate (37.5 percent * 0.7375) gives an effective residual value at new of 27.7 percent.

We add these four factors togeth er. At a 3 percent discount ra te, the consumer considers he could get 32.8 percent back upon re sale in 5 years, but will pay 10.4 percent more for loans, 5.5 percent more for taxes and 8.7 percent more in in surance, results in a 8.2 percent return on the increase in price for fuel economy technology (32.8 percent – 10.4 percent - 5.5 percent – 8.7 percent). Thus, the increase in price per vehicle is multiplied by 0.918 (1 – 0.082) before subtracting the fuel savings to determine the over all net consumer valuation the increase of costs on his purchase decision. At a 7 percent discount rate, the consumer considers he could get 27.7 percent back upon resale in 5 years, but will pay 9.5 percent more for loans, 5.5 percent more for taxes and 8.0 percent more in insu rance, results in a 4.7 percent re turn on the increase in price for fuel economy technology (27.7 percent – 9.5 per cent - 5.5 percent – 8.0 percent). Thus, the increase in price per vehicle is multiplied by 0.953 (1 – 0.047) before subtracting the fuel savings
to determine the overall net consumer valuation the increase of costs on his purchase decision.

Using sales volumes from Ward’s Automotiv e Yearbook 2008 for MY 2007 sales and the MY 2008 base vehicle average prices, 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 $26,201 and for all light trucks was $29,678. Wh ile this method does not give an exact price, the results are reasonable a nd specific to indi vidual manufacturers 230 . These prices are in

228 Based on www.bankrate.com auto loan calculato r for a 5 year loan at 6 percent.

229 For a 3 percent discount rate, 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. For a 7 percent discount rate, the summation of 3.2 percent x 0.9667 in year one, 3.2 x 0.9053 in year two, 3.2 x 0.8444 in year 3, 3.2 x 0.7891 in year 4, and 3.2 x 0.7375 in year 5.

230 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-15

2007 dollars. Average prices and estimated sales volumes are needed because price elasticity is an estimate of how a percent increase in pr ice affects the percent decrease in sales.

A sample calculation for Ford passenger cars und er the Optimized 7% alternative in MY 2011 is an estimated retail price increase of $119 which is multiplied by 0.953 to get a residual price increase of $113. The estimated fuel savings over the 5 years of $176 at a 7 percent discount rate results in a net benefit to consumers of $63. Comparing that to the $25,373 average price is a 0.247 percent price decrease. Ford sales were es timated to be about 1,615,000 passenger cars for MY 2011. With a price elasticity of –1.0, a 0.247 pe rcent decrease in net cost to consumers could result in an estim ated increase in sales of 3,997 passenger cars.

Combined passenger car and light truck sales decreas es are estimated for every alternative. As the alternatives get stricter, there are progressively larger losses in sales. Table VII-6 shows the estimated impact on sales for passenger cars and light trucks combined.

Our projections indicate that CAFE standard s will result in sales increases for some manufacturers under some scenarios, but overwhelm ingly decreases for the industry total. As the alternatives get progressively more stringent, the projected sales loss increases. For the TC = TB alternative the MY 2011 sales loss is pr ojected to be 86,000 or 0.5 percent and for the Technology Exhaustion alternative th e sales loss is proj ected to be 585,000 or 3.6 percent of the total sales of 16.136 million light vehicles.

Note that there is no feedback l oop between this sales an alysis and the Volpe model. These sales
estimates are not used to determine additional or less mileage traveled or fuel consumed. The Volpe model does not attempt to estimate the ex tent to which the sales volumes of different vehicle models might change in response to fuel economy increases, financial outlays for additional technology, and increases in civil penalties that could al l result from increased CAFE
standards. As NHTSA explained in the NPRM, (1) Volpe Ce nter staff tested many potential specifications of multinomial logit model that could be used to estimate such effects, but none produced plausible coefficients, (2) NHTSA and Volpe Center staff were not confident that baseline vehicle transaction pri ces could be reliably predicted, and (3) NHTSA and Volpe Center
staff were not confident a basis would be av ailable to estimate manufacturers’ decisions regarding the allocation of compliance costs. 231

As NHTSA further acknowledged in the NPRM, Resources for the Future (RFF) has, under contract to EPA, been working toward the deve lopment of a market share model. Although RFF did not complete this work in time for consider ation as part of this rulemaking, depending on the extent to which these efforts are eventually su ccessful, the Volpe model could at some point be
modified to include cost allo cation and market share models.

Among the attachments to its comments, the Al liance of Automobile Manufacturers submitted a study prepared by NERA, which used its model of the vehicle market “to estimate the value that consumers place on reductions in fuel operating cost while controlling for other factors.” 232

231 Federal Register / Vol. 73, No. 86 / Friday, May 2, 2008 / Proposed Rules, p. 24394.

232 NERA Economic Consulting, “Evaluation of NHTSA’s Benefit-Cost Analysis of 2011-2015 CAFE Standards”, 2008, p. 18.VII-16

NERA states that its model “operates at the leve l of individual vehicle mo dels” and “utilizes data on transaction prices (as distinct from manufacturers’ suggested re tail prices), sales volumes, and
detailed vehicle characteristic s for model years 2001 through 2007.” 233 With such a model, NERA may, in principle, have had the ability to estimate shifts in the market shares of individual vehicle models from these model years, if NERA had also been able to estimate how manufacturers would allocate overall compliance co sts. Of course, representing only past model years, such an analysis would have had uncertain relevance to future model years. In any event, NERA apparently did not attempt to do so, but in stead used NHTSA’s estimate of the own-price elasticity of demand for new vehicles to estimate the overall change in sales of new vehicles. 234 NHTSA and Volpe Center staff will continue to consider the potenti al to integrate a market share model into the Volpe model, and will give car eful consideration to the above-mentioned RFF effort when that work is complete. Howeve r, NHTSA received no concrete recommendations in response to its request for comments regarding th e formulation and calibration of a market share model, the estimation of future vehicle prices ( i.e. , transaction prices), and the estimation of manufacturers’ decisions regard ing the allocation of compliance costs. The Agency does not
have a sufficient basis to include a market share model into its Volpe model and analysis at this
time.

233 Ibid. , p. 18.

234 Ibid. , p. 27.VII-17

Table VII-6 Potential Impact on Sales by Manufacturer MY 2011 Passenger Cars and Light Trucks Combined

Manufacturer 25% Below Opt.
7% 25%
Above 50%
Above Opt.
3% TC = TB Tech

Ex.

BMW -1,123 -1,246 -1,381 -1,545 -1,529 -1,803 -3,934

Chrysler -3,232 -2,530 -10,394 -14,330 -3,892 -29,894 -156,924

Daimler -87 -97 -115 -130 -137 -162 -452

Ferrari -1 -1 -1 -2 -2 -2 -4

Ford 3,055 2,805 -9,883 -23,010 -21,059 -25,210 -85,413

General Motors -2,560 -2,560 -2,876 -924 186 -15,661 -123,844

Honda 818 818 818 818 963 1,360 -70,331

Hyundai 0 0 0 0 0 0 -71,561

Maserati 0 0 0 -1 -1 -2 -8

Mitsubishi 85 -3,156 -3,105 -3,731 -3,336 -4,063 -11,798

Nissan -661 -661 -744 -744 78 -4,936 -24,752

Porsche -88 -92 -98 -102 -96 -113 -263

Subaru -81 -136 -190 -263 -185 -390 -2,058

Suzuki -338 -443 -517 -657 -608 -906 -2,515

Tata -688 -688 -694 -701 -662 -713 -2,221

Toyota -1,993 -1,993 -2,192 -2,192 -1,920 -2,392 -24,986

Volkswagen -601 -777 -957 -1,191 -1,122 -1,547 -4,208

Total/Average -7,496 -10,757 -32,329 -48,704 -33,323 -86,434 -585,272VII-18VII-19

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 au tomobile companies and their suppliers to do research and development and testing on new te chnologies to determin e their capabilities, durability, platform introduction, etc. The ag ency does not anticipa te a huge number of incremental jobs in the engineer ing 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 th at 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 th an 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). 235 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 woul d be a likelihood of sales losses well into the hundreds of thousands of units and job losses we ll into the tens of thousands. Sales and employment losses of these magnitudes would ha ve 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 “... do mestic 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 o ff 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 re cent 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 Manufactur ing 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 2005 236 . Averaging those three years, the average U.S. domestic empl oyee 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.

235 T he agency’s decision to lower standards based on that am ount of impacts identified in the 1985 rule was upheld by the DC Circuit in Public Citizen v. NHTSA , 848 F.2d 256.

236 Based on “U.S. Automotive Industry Employment Trends ”, Office of Aerospace and Au tomotive Industr ies, U.S. Department of Commerce, March 30, 2005, and Ward’s Automotive Yearbook, 2006, pgs. 215, 222, and 270.VII-20

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, cons umers can elect to defer vehicle purchases by continuing to operate existing vehicles. Eventu ally, however, the rising maintenance costs for aging vehicles will make replacements look more attractive.

However, vehicle owners may also react to pe rsistently 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.VII-21

Table VII-8

Impact on Auto Industry Em ployment by Alternative

(Jobs)

MY 2011

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 272 -986 -714 Optimized (7%) -39 -986 -1,024 25% Above Optimized (7%) -1,336 -1,743 -3,079 50% Above Optimized (7%) -2,896 -1,743 -4,638 Optimized (3%) -2,419 -755 -3,174 TC = TB (7%) -5,375 -2,857 -8,232 Technology Exhaustion (7%) -37,260 -18,481 -55,740

Table VII-9 provides further inform ation relating to the stringency of the different alternatives. It looks at the largest 17 passe nger car manufacturers and the 15 light truck manufacturers and examines whether or not they run out of tec hnologies that the agency believes they have available. As the alternatives get more stringent , more manufacturers run out of technologies.

It should be noted that Table VI I-9 does not take into account any of the flexibilities that
manufacturers have available to co mply with a standard. It does not consider credits, credit trading, etc.

Table VII-9
Number of Manufacturers Th at Run Out of Technology

Cars Light Trucks 25% Below Optimized (7%) 7 10 Optimized (7%) 7 10 25% Above Optimized (7%) 9 10 50% Above Optimized (7%) 11 10 Optimized (3%) 11 10 TC = TB (7%) 11 10 Technology Exhaustion (7%) 16 15VIII-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 ye ar when a model is offered for sale through the year when nearly all vehicles from that model y ear have been retired or scrapped (assumed to be 26 years for passenger cars and 36 year s for light trucks in this anal ysis). 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-dut y vehicles produced. Reducing gasoline consumption provides consum er 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 drivi ng 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 fu el consumption and pollution savings, all due to an increase in driving that results from lower driv ing costs (the rebound effect). Each of these impacts is measured by comparing their value un der each alternative approach to their value under the adjusted baseline. Future impacts ar e estimated after discoun ting to the year the vehicle is sold to determine their present value. 237

Basic Inputs for Analysis of Economic Impacts The variety of impacts discussed above are a fu nction 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, a nd the relationship between EPA measured fuel efficiency and actual on-road fuel efficiency.

The Discount Rate Discounting future fuel savings and other benef its 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 per cent decline in the value of these benefits – as viewed from today’s perspective – for each year th ey are deferred into the future. In setting the standards using a marginal cost/marginal bene fit methodology we used two different discount rates. The inter-generational disc ount rate used for the long term so cial cost of car bon benefits is 3 percent and the conventional disc ount rate used for the fuel and other savings over the next 36 year is 7 percent. See the discussion in Chap ter I on docket comments fo r the basis for selecting
these rates.

237 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 produc tion costs for making thos e vehicles more fuelefficient, which are assumed to be incurred at the time those vehicles are manufactured.VIII-2

Vehicle Classification Passenger automobiles were defined in EPCA as “any automobile (other than an automobile capable of off-highway opera tion) which the Secretary [ i.e. , NHTSA] decides by rule is manufactured primarily for use in the transporta tion of not more than 10 individuals.” Thus, under EPCA, there are two general groups of automobiles that qualify as non-passenger automobiles or light trucks: (1) those define d by NHTSA in its regul ations as other than passenger automobiles due to their having not b een manufactured “primar ily” for transporting up to ten individuals; and (2) those expressly excluded from the pa ssenger category by statute due to their capability for off-highway operation, regardless of whethe r they were manufactured primarily for passenger transportation. NHTSA’s classification rule dire ctly tracks those two broad groups of non-passenger autom obiles in subsections (a) and (b), respectively, of 49 CFR

Part 523.5.

In the NPRM, NHTSA took a fresh look at the regul atory definitions in light of its desire to ensure clarity in how vehicles are classifie d, the passage of EISA, and the Ninth Circuit’s
decision in CBD . The NPRM proposed to tighten the c overage of its regulatory definition of “light truck” to ensure that, starting in MY 2011, 2WD versions of SUVs are no longer classified as off-highway capable light trucks under 49 CFR Part 523.5(b), simply because the SUV also
comes in a 4WD version.

NHTSA has tightened the coverage of its regulatory definition of “ light truck” to ensure that 2 wheel drive (2WD) versions of an SUV are not classified as light tr ucks under Part 523.5(b) simply because the SUV also comes in a 4WD version. In order to be properly classifiable as a light truck under Part 523, a 2WD SUV must e ither be over 6,000 lbs GVWR and meet 4 out of 5 ground clearance characteristics to make it o ff-highway capable under Part 523.5(b), or meet
one of the functional character istics under Part 523.5(a) ( e.g. , greater cargo ca rrying capacity than passenger carrying capacity). In other wo rds, a 2WD vehicle of 6,000 lbs GVWR or less,
even if it has a sufficient number of clearance ch aracteristics, cannot be considered off-highway capable. This is based on the plain meaning of Pa rt 523.5(b) (which refers to a vehicle that “has” 4WD) and the statute (49 U.S.C. § 32901(a)(18)(b) speaks of a ve hicle that “is a 4-wheel drive automobile”). Additionally, 2WD SUVs may not be properly classified as light trucks simply
because a manufacturer asserts that their base fo rm has no back seat and thus would “provide greater cargo-carrying than pa ssenger-carrying volume” accordi ng to Part 523.5(a)(4). No change in the regulatory definition is needed. The clarification accomplishes NHTSA’s purpose. This clarification, which the vehicle manufacturers largely supported, resulted in the reclassification of an average of 1,400,000 2WD SUVs fr om light trucks to passenger cars in each of the five model years covered by the standards.

Additional discussion of vehicle cl assification is contained in the preamble to the final rule..

Sales Estimates

A critical variable affecting th e total economic benefits from improving light truck fuel economy is the number of vehicles likely to be produced un der stricter fuel economy. Projections of total passenger cars and light truck sales for futu re years (see Table VIII-1a and VIII-1b) were obtained from the Energy Information Administration’s (EIA) Annual Energy Outlook 2008VIII-3

( AEO 2008 ), a standard government reference for projections of energy production and consumption in different se ctors of the U.S. economy. 238 These values will be used as multipliers to estimate the overall impacts (both co sts and benefits) of changes in fuel economy
standards.

In all cases, manufacturers’ respective sales volumes were normalized to produce passenger car and light truck fleets which refl ected manufacturers’ re spective MY 2008 market
shares within the construct of th e projected aggregate vehicle sales volumes that were forecasted in EIA’s 2008 Annual Energy Outlook. NHTSA does so in order to develop a market forecast
that is realistic in terms of both its ov erall size and manufacturers’ market shares. The product
mix for each manufacturer that s ubmitted product plans was preserved and in the case of those than did not submit plans, the product mix was th e same as indicated in their pre-model year
2008 CAFE data.

NHTSA has relied on product plans from manuf acturers to help the agency determine the composition of the future fleets. The product plans are provided in response to NHTSA’s request for information from the manufacturers, and respond to very detailed questions about vehicle model characteristics that influence fuel economy. 239 The baseline market forecast mix of products (make/model, engines, transmissions, etc.) that NHTSA has used in its analysis is based significantly on th e confidential product plan inform ation manufacturers submit to the agency. See the preamble to the final rule for more information on how we used the
manufacturers’ confiden tial product plans.

238 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

.

239 Id.VIII-4

Table VIII-1

Sales Projections – MY 2011

(1,000s of vehicles)

Manufacturer Passenger Cars Light Trucks Combined

BMW 340.9 96.2 437.1
Chrysler 707.3 1,215.9 1,923.2

Daimler 52.9 23.0 75.9

Ferrari 1.9 1.9

Ford 1,615.0 1,143.9 2,759.0
General Motors 1,700.1 1,844.1 3,544.2

Honda 1,249.9 469.5 1,719.5
Hyundai 655.1 221.3 876.4

Maserati 4.4 4.4

Mitsubishi 209.8 16.9 226.8

Nissan 789.4 479.3 1,268.7

Porsche 13.5 25.8 39.3

Subaru 92.1 126.7 218.8

Suzuki 103.8 21.6 125.5

Tata 35.0 25.7 60.7

Toyota 1,405.1 1,094.5 2,499.6
Volkswagen 310.7 45.2 355.9

Total/Average 9,286.9 6,849.7 16,136.7VIII-5

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 ec onomy, as would result from more stringent fuel economy standards. The rebound effect occurs b ecause an increase in a vehicle’s fuel economy reduces its owner’s fuel cost for driving each mile, which is typical ly the largest single component of the cost of operating a vehicle. Ev en 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 expre ssed as the percentage by whic h 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 re duction 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 standard s, 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 th e 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. 240 When expressed as a positive percentage , either of these parameters gi ves the fraction of fuel savings
that would otherwise result from ad opting 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 significan t rebound effect occurs when vehicle fuel efficiency improves. 241 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 extende d time period in order to measur e the response of vehicle use to changing fuel economy. 242

An important distinction among studies of the re bound effect is whether they assume that the effect is constant, or varies over time in respons e to the absolute levels of fuel costs, personal income, or household vehicle ownership. Most st udies using aggregate annual data for the U.S.

240 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.

241 Some studies estimate that the long-run rebound effect is significantly larger than the immediate response to increased fuel efficiency. Al though 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.

242 In effect, these studies treat U.S. states as a data “p anel” by applying appropriate estimation procedures to data consisting of each year’s average values of these variables for the separate states.VIII-6

assume a constant rebound effect, although some of these studies test whethe r 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 a rrive at differing conclusions about whether the rebound effect is larger am ong households that own more vehicles. One recent study using state-level data concludes that the rebound effect va ries 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 an estimate of the rebound effect for use in assessing the fuel savings, emissions reductions, and other impa cts 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 th e long-run rebound effect reported in these studies, which is
summarized in the table below. 243 As the table indicates, thes e 66 estimates of the long-run rebound effect range from as low as 7 percent to as high as 75 pe rcent, 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 m ean (24 percent), while focusing on the authors’ preferred estimates from published studies narr ows this range and lo wers its average only slightly. The median estimate of the rebound eff ect in all three samples, which is generally regarded as a more reliable indicator of their cen tral tendency than the average because it is less influenced by unusually small and large estimates, is 22 percent. As Table VIII-2 indicates, approximately two-thirds of all estimates review ed, of all published estimates, and of authors’ preferred estimates fall in th e range of 10-30 percent.

Table VIII-2 Summary of Rebound Effect Estimates
Range Distribution Category of Estimates Number of
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 consta nt and variable rebound effects.

243 In some cases, NHTSA derived estimates of the overall rebo und 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-7

(2) Reported estimates updated to reflect 2006 valu es 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 percen t 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 me dian value (23 percent).

In selecting a single valu e for the rebound effect to use in analyzing alternative standards for future model years, NHTSA attaches greater sign ificance to studies that allow the rebound effect to vary in response to changes in the various fact ors that have been found to affect its magnitude. However, it is also important to update authors’ originally-report ed estimates of variable rebound
effects to reflect current conditi ons. Recalculating the 29 original estimates of variable rebound effects to reflect current (2006) values for re tail fuel prices, average fuel economy, personal income, and household vehicle ownership reduc es their median estimate to 16 percent. 244 NHTSA also tentatively attaches greater signi ficance to the recent study by Small and Van Dender (2005), which finds that the rebound effect tends to dec line as average fuel economy, personal income, and suburbanization of U.S. cities increase, but – in accordance with previous studies – rises with increasing fuel prices. 245

Considering the empirical evidence on the rebound effect as a whole, but according greater importance to the updated estimates from st udies 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 savi ngs and other effects of alterna tive standards for the time period

244 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 fu el 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 es timates 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 Economic s 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.

245 In the most recent light truck CA FE 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-8

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 percen t appears to be appropriate fo r the required analysis of the uncertainty surrounding these estimates.

NHTSA has updated the 29 estimates from studies that allowed the rebound effect to vary to reflect current (2008 to date) fu el prices, fuel economy, vehicl e ownership levels, and household income. The resulting updated estimates are si gnificantly higher than those reported in the NPRM, primarily because of the la rge increase in fuel prices sin ce 2006 (the date to which the estimates reported in the NPRM were update d). The updated 2008 estimates of the fuel economy rebound effect range from 8 percent to 46 pe rcent, with a median value of 19 percent. Using the average retail gasoline price forecas t for 2011-30 from the AEO 2008 High Price case, the projected estimates of the rebound effect fo r those years would range from 7 percent to 46 percent, with a median value of 19 percent. Fina lly, NHTSA notes that the forecast of fuel prices used to develop its adopted CAFE standards fo r model years 2011 projec ts that retail gasoline prices will continue to rise by somewhat more than 1 percent annually over the lifetimes of vehicles affected by those standards. At the sa me time, real household incomes are projected to grow by about 2 percent annually ov er this same period. Given th e relative sens itivity of the
Small and Van Dender rebound effect estimate to changes in fuel prices and income, these forecasts suggest that future growth in fuel prices is likely to offset a significant fraction of the projected decline in the rebound effect that would result from income growth.

In light of these results , NHTSA has elected to continue to use a 15 percent rebound effect in its analysis of fuel savings and ot her benefits from higher CAFE standards for this final rule. Recognizing the uncertainty surrounding this estimat e, the agency has analyzed the sensitivity of its benefits estimates to a range of values for the rebound effect from 10 percent to 20 percent. In its future CAFE rulemaking activities, NHT SA plans to prepare detailed year-by-year forecasts of the magnitude of the rebound effect using the published studies it regards as most reliable, in conjunction with fo recasts of fuel prices, household income growth, and vehicle ownership levels. This analysis will indicate whether the combined effect of future changes in the factors that past research has shown to influe nce the rebound effect is likely to be an increase or a reduction in its future magnitude. NHTSA will base the estimate of the rebound effect it employs in analyzing future CAFE standards on th e projected future values of the rebound effect
over the lifetimes of vehicles a ffected by those standards.

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 published fuel economy ratings for different mode ls. In analyzing the fuel savings from alternative passenger car and light truck CAFE standards, the ag ency adjusts the actual fuel economy performance of each passenger car and light truck model downward from its rated value to reflect the expected si ze of this on-road fuel economy “gap.” In December 2006, EPAVIII-9

adopted changes to its regulations on fuel ec onomy labeling, which we re intended to bring vehicles’ rated fuel economy le vels closer to their actual on-road fuel economy levels. 246

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. 247 For example, if the overall EPA fuel econo my rating of a light truck is 20 mpg, the onroad fuel economy actually achieved by a typical dr iver of that vehicle is expected to be 16 mpg (20*.80). The agency has employed EPA’s revised es timate of this on-road fuel economy gap in its analysis of the fuel savings resulting fr om 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 ve hicles 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 th e fuel economy levels corresponding to that
alternative. The sum of these annual fuel savings over each calenda r year that a vehicle remains in service represents the cumulative fuel savi ngs resulting from applying the alternative to vehicles produced during that model year.

As previously noted, actual fuel economy leve ls 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 mode ls. In analyzing the fuel savings from alternative passenge r car and light truck CAFE sta ndards, 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 th is 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 le vels closer to their actual on-road fuel economy levels. 248

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. 249 The agency has employed EPA’s revised es timate of this on-road fuel economy gap in

246 EPA, Fuel Economy Labeling of Motor Vehicles: Revisions To Improve Ca lculation of Fuel Economy Esti mates; 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

.

247 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/fue leconomy/420r06017.pdf

. 248 EPA, Fuel Economy Labeling of Motor Vehicles: Revisions To Improve Ca lculation of Fuel Economy Esti mates; 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

.

249 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/fue leconomy/420r06017.pdf

.VIII-10

its analysis of the fuel savings resulting fr om alternative CAFE standards for MY 2011-2018 passenger cars and MY 2012-18 light trucks.

The number of light vehicles manufactured duri ng each model year that remains in service during each subsequent calendar year is estim ated by multiplying the estimated proportions of vehicles expected to survive to each age up to 26 years for passenger cars (Table VIII-3a) and 36 years for light trucks (Table VIII-3b) by the number of cars and light trucks forecast to be produced during each year. Thes e “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 dur ability and usage of more recent passenger car and light truck models. 250 Updated estimates of average annua l miles driven by vehicle age were developed from the Federal Highway Administ ration’s 2001 National Hous ehold Transportation Survey, and these also differ from the estimates of annual mileage employed in past NHTSA analyses. 251 The total number of miles driven by ve hicles 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-3a and VIII-3b 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 house hold 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 per cent of the vehicles originally prod uced. 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 resu lting 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 ru le 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 su rvival-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, part icularly after discounting those benefits to their present values.

The primary source of data for determining ve hicles 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 passenge r cars and light trucks registered for on-road operation in the United States. NVPP registratio n data was used from vehicle model years 1977

250 The survival rates were calculated from R.L. Polk, Na tional 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.

251 See also NHTSA, “Vehicle Survivability and Travel M ileage Schedules,” Office of Regulatory Analysis and Evaluation, January 2006, pp. 15-17.VIII-11

to 2003. Survival rates were averaged for the fi ve 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 ca rs or light trucks surviving to that age. The survival rates predicted by these models are used to deve lop 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 Statis tics, 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 previ ous national travel surveys: the Federal Highway Administration-sponsored Nationwide Personal Tran sportation Survey (NPTS) and the Bureau of Transportation Statistics-sponsored American Travel Survey (ATS). 252 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 th e estimates of average annual m iles 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 subs equent increases in fuel prices, the estimates of annual vehicle use derived from the NHTS are adjusted to reflect pr ojected future gasoline prices using the rebound effect, which is discussed in detail later in this ch apter. Two factors affect the cost of gasoline per mile driven - fuel prices per gallon, and fuel econo my 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 econo my levels that prevai led during 2001 and 2002, when the survey was conducted. In analyzing the final ru le, 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, whic h exceed those that existed during 2001-2002.

Specifically, the adjustment accounted for the differe nce between the average price per gallon of fuel forecast over the expected lifetimes of m odel year 2011 passenger cars and light trucks 253 and the average price that prevailed during 2000 and 2001. When expressed in percentage terms, this difference was assumed to represent the percent increas e in fuel cost per mile driven between the time the survey was conducted and the time period when model year 2011 passenger cars and light trucks
would be in service.

The same elasticity of annual vehicl e use with respect to fuel cost pe r mile that was used to estimate the increase in vehicle use resulting from improve d fuel economy (see detailed discussion of the “rebound effect” earlier in this chap ter), assumed to be –0.15, was applie d to this percent difference to adjust the estimates of vehicle use derived from the survey to reflect the eff ect of higher future fuel prices. In contrast, this adjust ment reduces model year 2011 passenge r cars’ and light trucks’ average annual usage at each age to account for the fact that fu el cost per mile driven is expected to be 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 estimate d to be 161,847 for passenger cars and 190,066 for

252 For details on survey coverage and procedures, see http://nhts.ornl.gov/quickStart.shtml

. 253 Based on the AEO High price forecast from the AEO 2008 report.VIII-12

light trucks. After adjusting fo r the rebound effect, the average lifet ime mileage is estimated to be 146,547 for passenger cars and 171,590 for light trucks.VIII-13

Table VIII-3a 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 0.8604 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 161,847VIII-14

Table VIII-3b 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 190,066VIII-15

Table VIII-3c
Survival Rates and Annual Vehicle-Miles Tr aveled (VMT) Adjusted for Rebound Effect by Age for Passenger Cars

Vehicle Age Estimated Survivability Adjusted VMT Weighted Yearly
Travel Miles 1 0.9950 12,885 12,821 2 0.9900 12,641 12,515 3 0.9831 12,377 12,167 4 0.9731 12,094 11,769 5 0.9593 11,796 11,316 6 0.9413 11,484 10,810 7 0.9188 11,160 10,253 8 0.8918 10,825 9,654 9 0.8604 10,483 9,020 10 0.8252 10,135 8,363 11 0.7866 9,783 7,695 12 0.7170 9,429 6,760 13 0.6125 9,075 5,558 14 0.5094 8,722 4,443 15 0.4142 8,374 3,469 16 0.3308 8,032 2,657 17 0.2604 7,698 2,005 18 0.2028 7,374 1,495 19 0.1565 7,061 1,105 20 0.1200 6,763 812 21 0.0916 6,481 594 22 0.0696 6,217 433 23 0.0527 5,972 315 24 0.0399 5,750 229 25 0.0301 5,551 167 26 0.0227 5,379 122 Adjusted Lifetime Passenger Car VMT 146,547VIII-16

Table VIII-3d
Survival Rates and Annual Vehicle-Miles Tr aveled (VMT) Adjusted for rebound Effect by Age for Light Trucks

Vehicle Age Estimated Survivability Adjusted VMT Weighted Yearly
Travel Miles 1 0.9950 14,521 14,449 2 0.9741 14,248 13,879 3 0.9603 13,941 13,388 4 0.9420 13,604 12,815 5 0.9190 13,241 12,168 6 0.8913 12,855 11,457 7 0.8590 12,449 10,694 8 0.8226 12,028 9,895 9 0.7827 11,596 9,076 10 0.7401 11,155 8,256 11 0.6956 10,710 7,450 12 0.6501 10,264 6,673 13 0.6042 9,821 5,934 14 0.5517 9,385 5,178 15 0.5009 8,960 4,488 16 0.4522 8,548 3,865 17 0.4062 8,154 3,312 18 0.3633 7,781 2,827 19 0.3236 7,434 2,406 20 0.2873 7,115 2,044 21 0.2542 6,829 1,736 22 0.2244 6,579 1,476 23 0.1975 6,369 1,258 24 0.1735 6,203 1,076 25 0.1522 6,084 926 26 0.1332 6,015 801 27 0.1165 6,001 699 28 0.1017 6,001 610 29 0.0887 6,001 532 30 0.0773 6,001 464 31 0.0673 6,001 404 32 0.0586 6,001 352 33 0.0509 6,001 305 34 0.0443 6,001 266 35 0.0385 6,001 231 36 0.0334 6,001 200

Adjusted Lifetime Light Truck VMT 171,590VIII-17

In interpreting the survivability and annual mil eage estimates reported in Tables VIII-2a through VIII-2d, it is important to understand that vehicl es 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 typica l are first offered for sale in June through September of the preceding calendar year (for exam ple, sales of a model year typically begin in June through September of the previous calendar year, depending on manufacturer). Thus virtually a ll 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. 254 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 th eir maximum age of 36 years in calendar year 2043 (2008 + 35 = 2043).

To determine the impact of improved CAFE standa rds, fuel consumption is calculated using both
current and revised CAFE levels. The differen ce between these estimates represents the net savings from increased CAFE standards. With th e current CAFE standard assumed to remain in effect, total fuel consumption by each model ye ar’s vehicles during ea ch calendar year they
remain in service is calculated by dividing the total num ber of miles they are driven during that year by the average on-road fuel economy level they would achiev e 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 duri ng each future calendar year is calculated by dividing the total number of m iles they are driven by the hi gher on-road fuel economy level
associated with that stricter CAFE standard. Th e total number of miles that vehicles are driven each year is different under the final rule than wi th 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 resu lt 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 fu el economy, subsequent owners of that same vehicle will continue to experien ce the resulting fuel savings un til the vehicle is retired from service. It is important to note, however, th at 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 anal ysis. Due to the patter n 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 consid ered. The agency believes that CAFE standards
should reflect the true economic value of resources that are saved when less fuel is produced and

254 One complication arises because registration data are ty pically 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 exte nt possible, any externalities that impact the broader society. Consumers’ perceptions of thes e 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 lifet ime. While a vehicle’s buyer ma y 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 pri ces to the length of time the buye rs of new vehicles typically own the vehicles they purchase, under the as sumption that their purchase decisions will be influenced only by the benefits th ey receive during the time they e xpect 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. 255 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.

As noted in Chapter 1, the economic value of fu el savings resulting from the final rule is estimated by applying the forecast of future fu el prices from the High Price Case from the Energy Information Administration’s Annual Energy Outlook 2008 to each future year’s estimated fuel savings. 256 (The uncertainty analysis repor ted in Chapter X uses fuel price
forecasts from the Low and Reference Oil Price Scenarios included in AEO 2008 to examine the effects a range of possible fu el price scenarios) The AEO 2008 forecast of future fuel prices, which is reported in Table VIII-4, represents retail prices per gallon of fuel, which includes Federal, State, and any applicable local taxes. While the retail pr ice 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 re flect the economic value of fuel sa vings to society as a whole.

First, Federal and State taxes are excluded from th e social value of fuel savings because these do
not reflect costs of resources us ed in fuel production, and thus do not reflect resource savings that would result from reducing fu el consumption. Instead, fuel ta xes simply represent resources that are transferred from one segment of the popu lation 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 va lue of government-financed servi ces by approximately that same
amount. The benefit derived from lo wer taxes to individuals is thus likely to be offset exactly by
a reduction in the value of serv ices provided to society.

Second, the economic cost of exte rnalities generated by imports and consumption of petroleum products will be reduced in proportion to gasoline savings resulting from the final rule. The

255 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/

. 256 U.S. Department of Energy, Energy Information Administration, Annual Energy Outlook 2008 , High Price Case Table 12, http://www.eia.doe.gov/oiaf/aeo/excel/aeohptab_12.xls

.VIII-19

estimated economic value of these externalities is conve rted into its per-gallon equivalent and added to the pre-tax price of ga soline in order to measure this additional benefit to society for each gallon of fuel saved. This also allows th e magnitude of these exte rnalities to be easily compared to the value of the resources save d from reduced fuel production and use, which represents the most important component of th e social benefits from saving gasoline. A discussion of these externality values is in cluded in the next sec tion of this chapter

Table VIII-4 illustrates the adjustment of forecast re tail 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 econo mic externalities from petroleum use shown in the table is explained in detail in the following section. While the High Price Case fuel price forecasts reported in AEO 2008 extend through 2030, the agency’s analysis of the value of fuel savings over the 26-year maximum lifetimes of MY 2011 passenger cars and 36-year maximum lifetimes MY 2011 light trucks requires forecas ts extending through calendar year 2050. The agency assumes that retail fuel prices will re main at the 2030 forecast values reported in the AEO 2008 High Price Case forecast over the period from 2030 through 2052 (in constant-dollar terms). As Table VIII-4 show s, the projected retail price of gasoline expressed in 2007 dollars rises steadily over most of the forecast period, from $2.95 in 2011 to $3.51 in 2024, and then decreasing for a few years until it reaches $3.62 in 2030. As mentioned above, it is assumed to remain 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 es timate the value to society of saving gasoline. The agency has updated its estimat es of gasoline taxes, using upda ted State tax rates reported for January 1, 2006 257 expressed in 2007 dollars, Federal ga soline taxes are currently $0..184, while State and local gasoline taxes together average $0.236 per gall on, for a total tax burden of $0.420 per gallon.

Following the assumptions used by EIA in its National Energy Modeling System (NEMS), state and local gasoline taxes are assume d to keep pace with inflation in nominal terms, and thus to remain constant when expressed in constant 2007dollars. In cont rast, federal gasoline taxes are assumed to remain unchanged in nominal terms, and thus to decline throughout the forecast period when expressed in constant 2007 dollars. These differing assumptions about the likely
future behavior of federal and state/local fuel taxes are consistent w ith recent historical experience, and reflect the fact that Federal motor fuel taxes a nd most State taxes are specified on a cents-per-gallon basis (some State taxes are levi ed as a percentage of the wholesale price of fuel), and typically require legislation to change.

Actual fuel economy levels achie ved by light-duty vehicles in on -road driving fall somewhat
short of their levels measured under the laborato ry-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 prev iously adjusted the actual fuel economy performance of each light truck model downward from its rated value to reflect the expected size

257 FHWA, Highway Statistics 2006 , Section I: Motor Fuel -- Rates and Revenues, Table MF-121T,
available at http://www.fhwa.dot.gov/policy/ohim/hs06/pdf/mf121t.pdf

.VIII-20

of this on-road fuel economy “gap.” On December 27, 2006, EPA adopted changes to its regulations on fuel economy labe ling, which were intended to bri ng vehicles’ rated fuel economy
levels closer to their actual on-road fuel economy levels. 258

In its Final Rule, EPA estimated that actual on-road fuel economy for light-duty vehicles averages 20 percent lower than published fuel ec onomy levels. For example, if the overall EPA fuel economy rating of a light tr uck is 20 mpg, the on-road fuel economy actually achieved by a typical driver of that vehicl e 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.

258 71 FR 77871 (Dec. 27, 2006).VIII-21

Table VIII-4 Adjustment of Forecast Retail Gasoline Price to Reflect Social Value of Fuel Savings

Year AE0 2008 Forecast of
Retail Gasoline Price (2007 $/gallon) Estimated Federal
and State Taxes (2007 $/gallon) Forecast Gasoline Price Excluding Taxes

(2007 $/gallon) Forecast Gasoline Price Including Externalities (2007 $/gallon)
2011 $2.949 $0.420 $2.529 $2.911
2012 $2.974 $0.416 $2.558 $2.939
2013 $3.023 $0.412 $2.611 $2.993
2014 $3.077 $0.409 $2.668 $3.049
2015 $3.093 $0.405 $2.688 $3.069
2016 $3.138 $0.402 $2.736 $3.117
2017 $3.200 $0.399 $2.801 $3.182
2018 $3.241 $0.395 $2.846 $3.228
2019 $3.301 $0.392 $2.909 $3.291
2020 $3.363 $0.388 $2.975 $3.357
2021 $3.451 $0.385 $3.066 $3.447
2022 $3.491 $0.381 $3.110 $3.491
2023 $3.492 $0.378 $3.114 $3.496
2024 $3.510 $0.374 $3.136 $3.518
2025 $3.485 $0.371 $3.114 $3.496
2026 $3.494 $0.371 $3.123 $3.504
2027 $3.518 $0.371 $3.147 $3.529
2028 $3.545 $0.371 $3.174 $3.555
2029 $3.576 $0.371 $3.205 $3.586
2030-2052 $3.618 $0.371 $3.247 $3.628

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 di rect costs associated with petroleum use and fuel production to current fuel taxes. The bene fits of more stringent fuel economy standards include the market value of the savings in resour ces from producing less fu el, together with the resulting reductions in the costs of economic externalities associated with petroleum consumption, and of environmental externalitie s caused by fuel consumption and production.
Environmental externalities include adverse health impacts associated with criteria pollutants and environmental damage associated with greenhou se 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 cau sed 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 e xpect to own a vehicle, while the value to the U.S. economy of saving fuel is measured by its pr e-tax price, and includes fuel savings over theVIII-22

entire lifetime of vehicles. Thus, it cannot simply be assumed that the interaction of
manufacturers’ costs and vehicl e buyers’ demands in the private marketplace will determine optimal fuel economy levels, and that these leve ls should only be adjusted by Federal regulation if the external costs of fuel producti on and use exceed current fuel taxes.

The Agency’s analysis estimates the value of eac h category of benefits an d 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 acco unting 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 pa ssenger 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 petrol eum, or in the prices paid by consumers of petroleum products such as gasoli ne. 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 ma intaining a U.S. military presence to secure imported oil supplies from unstabl e regions, and for maintaining th e 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 ex ternal 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 pe troleum or refined fu els 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.

Demand costs Increased U.S. oil imports can impose higher co sts 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 oi l 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 dema nd 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 th e global petroleum market in ex cess of the higher prices paid by U.S. consumers. 259 Conversely, reducing U.S. oil im ports can lower the world petroleum price, and thus generate benef its to other oil purchasers by reducing these “monopsony costs.”

259 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 barre l, the daily U.S. import bill rises to $891 million. The resulting increase of $91 million per day ($891 million minus $800 million) is attributable to increasing daily imports by only 1 million barrels. This means that the incremental cost of importi ng each additional barrel is $91, or $10 more than the newly-VIII-23

Although the degree of current OP EC monopoly power is subject to considerable debate, the consensus appears to be that OPEC remains able to exercise some degr ee 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. 260 The extent of U.S. monopsony power is determined by a complex set of factors including the rela tive 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. 261

In analyzing benefits from its recent actions to increase light truck CA FE standards for model years 2005-07 and 2008-11, NHTSA relied on a 1997 st udy by Oak Ridge Na tional Laboratories (ORNL) to estimate the value of reduced econom ic externalities from petroleum consumption and imports. 262 More recently, ORNL updated its estimates of the value of these externalities, using the analytic framework developed in it s original 1997 study in conjunction with recent estimates of the variables and para meters that determine their value. 263 These include world oil prices, current and anticipated future levels of OPEC petr oleum 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 disrup tions. 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) 264

.

The updated ORNL study was subjected to a detaile d peer review and its estimates of the value of oil import externalities were subsequen tly revised to reflect their comments and
recommendations. 265 Specifically, reviewers recommended that ORNL increase its estimates of the sensitivity of oil supply by non-OPEC produ cers 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 in creases in world oil prices. After making

increased world price of $81 per barrel. This ad ditional $10 per barrel represents a cost imposed on all other purchasers in the globa l petroleum market by U.S. buyers , in excess of the price they pay to obtain those additional imports.

260 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/docim ages/pdf93/343894_we b.pdf (last accessed Dec. 2, 2007).

261 Id. , at 18-19.

262 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/d ocimages/pdf93/34389 4_web.pdf (last accesse d Dec. 2, 2007).

263 Leiby, Paul N. "Estimating the Energy Security Bene fits 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).

264 Federal Register Vol.72, #83, May 1, 2007 pp.23,900-24,014

265 Peer Review Report Summary: Estimating the Energy Security Benefits of Reduced U.S. Oil Imports

, ICF, Inc., September 2007.VIII-24

the revisions recommended by peer reviewers, ORNL’s updated estimates of the monopsony cost associated with U.S. oil imports range from $2.77 to $13.11per barrel, with a most likely estimate of $7.41 per barrel (2005$). 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 $0.066 to $0.312 per gallon, with th e actual value most likely to be $0.176 per gallon saved (2005$). The agency notes, however, that the mo nopsony cost varies directly with world oil prices, and that the forecast of wo rld oil prices used in this analysis differs significantly from that assumed in the ORNL study. Thus NHTSA has fu rther adjusted the updated ORNL estimate of the monopsony cost to reflect the AEO 2008 High Pri ce case forecast of world oil prices, which averages $88 per barrel (in 2007 dollars) ove r the period from 2011-30. Expressed in 2007 dollars, NHTSA’s revised estimates of the reductions in monopsony costs are $0.266 per gallon of fuel saved. This represents an economic benef it in addition to the value of savings in fuel production costs that would resu lt from improving fuel economy.



### Disruption and Adjustment Costs
The second component of external economic cost s 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. econom y 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-disrup tion 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 w ithout 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 busine sses and households for ad justing their use of petroleum products more rapidly than if the sa me 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 reach ed 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 othe r resources quickly and smoothly in response to rapid changes in prices for petroleum products.

Since future disruptions in forei gn oil supplies are an uncertain pr ospect, 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 va lue” of these costs – the product of the probability that an oil import disruption will occur and the costs of re duced 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 fr om 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 wi dely 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 resulti ng from a disruption of import supply. In addition, changi ng the quantity of petroleum impor ted into the U.S. may alsoVIII-25

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 supplie s 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 adjusti ng to sudden price increases. While the availability of these market mechan isms has likely reduced the potential costs of disruptions to the supply of imported oil, consum ers of petroleum products are unlikely to take account of costs they impose on others, so these co sts are probably not refl ected in the price of imported oil. Thus changes in oil import levels pr obably continue to affect the expected cost to the U.S. economy from potential oil supply disr uptions, although this co mponent 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 estimat es 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 $2.10 to $7.40 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 disr uptions to the U.S. economy by $0.050 to $0.176, with the actual value most likely to be $0.109 per gallon (2005$). Updated to 2007 dollars, the value of oil supply disruptions is estimated to be $.116 per gallon. Like the reduction in monopsony costs, the reduction in expected disrupti on 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 Strate gic Petroleum Reserve Costs The third component of the exte rnal economic costs of importing oil into the U.S. includes government outlays for maintaining a military presen ce to secure the supply of oil imports from potentially unstable regions of the world and to protect against their inte rruption. 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 protecti ng the U.S. economy from oil supply disruptions.

NHTSA currently believes that while costs for U.S. military security may vary over time in response to long-term changes in the actual level of o il 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 protecting oil supplies, and as a conse quence are unlikely to vary significantly in response to changes in the level of o il imports prompted by higher standards.

Neither the Congress nor the Executive Branch ha s ever attempted to calibrate U.S. military expenditures, force levels, or deployments to any oil market variable, or to some calculation of the projected economic consequences of hostilities in the Persian Gulf. Instead, changes in U.S. force levels, deployments, and thus military spe nding in that region have been largely governedVIII-26

by political events, emerging threats, and other mili tary and political considerations, rather than by shifts in U.S. oil consumption or imports. NHTSA thus concludes that the levels of U.S. military activity and expenditures are likely to remain unaffected by even relatively large changes in light duty vehi cle fuel consumption.

Nevertheless, the agency conducted a sensitivity analysis of the pot ential effect of assuming that some reduction military spending would result from fuel savings and reduced petroleum imports in order to investigate its im pacts on the standards and fuel savings. Assuming that the preceding estimate of total U.S. military costs fo r securing Persian Gulf oil supplies is correct, and that approximately half of these expenses could be reduced in propor tion to a reduction in U.S. oil imports from the region, the estimated savings would range from $0.02 to $0.08 (in 2007 dollars) for each gallon of fuel savings that was reflected in lower U.S. imports of petroleum
from the Persian Gulf. If the Pe rsian Gulf region is assumed to be the marginal source of supply for U.S. imports of crude petroleum and refined products, then each gallon of fuel saved might reduce U.S. military outlays by $0.05 per gallon, the midpoint of this range. NHTSA employs this estimate in its sensitivity analysis.

Similarly, while the optimal size of the SPR from the standpoint of its potential influence on domestic oil prices during a suppl y disruption may be related to th e 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 ot her 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’ analysis of benefits from alte rnative CAFE standards does not in clude 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 pe troleum imports by means of tightening future
standards. This view concurs with that of the re cent ORNL study of economic costs from U.S. oil imports, which concludes that savings in gov ernment outlays for these purposes are unlikely to result form modest reductions in consump tion of petroleum produc ts and oil imports.

Thus, for purposes of setting the MY 2011 standa rds, NHTSA has included only the likely reductions in monopsony and disrupti on costs from lower U.S. petroleum imports in its estimate of the savings in external economic costs fr om reducing fuel consumption. The updated and revised ORNL estimates suggest that the comb ined reduction in monopsony costs and expected costs to the U.S. economy from oil supply disr uptions resulting from lower fuel consumption total $0.152 to $0.657 per gallon, with a most likely estimate of $0.381 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 fo r producing and distributing each gallon of fuel saved. NHTSA employed this estim ate in its analysis of the benefits from fuel savings projected to result from alterna tive CAFE standards for model year 2011.

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 Refe rence Case, High Economic Growth, and Low Economic Growth Scenarios presented in the Energy Information Administration’s Annual Energy Outlook 2008 , the agency estimates that approxima tely 50 percent of the reduction inVIII-27

fuel consumption resulting from adopting higher CAFE standards is likel y 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 perc ent 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 pr oduction of crude petroleu m. 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 petrol eum or refined fuel by 0.95 gallons. 266

Emissions Reductions Result ing from Fuel Savings

Emissions of carbon dioxide and other greenhou se gases (GHGs) occur throughout the process of producing and distributing transportation fuels, as well as from fuel combustion itself. By reducing the volume of fuel consumed by passe nger cars and light trucks, higher CAFE
standards will thus reduce GHG emis sions generated by fuel use, as well as throughout the fuel supply cycle. Lowering these emissions is like ly to slow the projec ted pace and reduce the ultimate extent of future changes in the global climate, thus reducing future economic damages that changes in the global climate are otherwise expected to cause. Further, by reducing the probability that climate changes with potenti ally catastrophic economic or environmental impacts will occur, lowering GHG emissions may al so result in economic benefits that exceed the resulting reduction in the expected future economic costs caused by gradual changes in the earth’s climatic systems.

Quantifying and monetizing benefits from reducing GHG emissions is thus an important step in estimating the total economic benefits likely to re sult from establishing higher CAFE standards.
Since direct estimates of the economic benef its from reducing GHG emissions are generally not reported in published literature on the impacts of climate change, these benefits are typically assumed to be the “mirror image” of the estimated incremental costs resulting from an increase in those emissions. That is, the benefits from reducing emissions are usually measured by the savings in estimated economic damages that an e quivalent increase in emissions would otherwise
have caused.

Researchers usually estimate the economic costs of increased GHG emissions in several steps. The first is to project future changes in the global climate and the resulting economic damages that are expected to result under a baseline projection of net global GHG emissions. These projections are usually developed us ing models that relate concentr ations of GHGs in the earth’s atmosphere to changes in summary measures of the global climate such as temperature and sea levels, and in turn estimate the reductions in glob al economic output that are expected to result from changes in climate. Since the effects of GHG emissions on the global climate occur decades or even centuries later, and there is cons iderable inertia in the earth’s climate systems, changes in the global climate and the resulti ng economic impacts must be estimated over a comparably long future period.

Next, this same process is used to project future climate changes and resulting economic damages under the assumption that GHG emissions increase by some increment during a stated future year. The increase in projected globa l economic damages resu lting from the assumed

266 This figure is calculated as 0.50 + 0.50*0.9 = 0.50 + 0.45 = 0.95.VIII-28

increase in future GHG emissions, which also o ccurs over a prolonged peri od extending into the distant future, represents the added economic costs resulting from the assumed increase in
emissions. Discounted to its curre nt value as of the year when the increase in emissions are expected to occur and expressed per unit of GHG emissions (usua lly per ton of carbon emissions,
with non-CO 2 GHGs converted to their equivalents in terms of carbon emissions), the resulting value represents the global economic cost of increasing GHG emissions by one unit – usually a metric ton of carbon – in a stated future year. This value is often referred to in published research and debates over climate policy as the Social Cost of Carbon (SCC), and applies specifically to increased emissions during that year.

This process involves multiple sources of uncerta inty, including those in scientific knowledge about the effects of varying le vels of GHG emissions on the magnitude and timing of changes in the functioning of regional and global climatic an d ecological systems. In addition, significant uncertainty surrounds the anticipa ted extent, geographic distributi on, and timing of the resulting impacts on the economies of nations located in di fferent regions of the globe. Because the climatic and economic impacts of GHG emissions are projected to occur over the distant future, uncertainty about the correct rate at which to discount these futu re impacts also significantly
affects the estimated economic be nefits of reducing GHG emissions.

Researchers have not yet been able to quantif y many of the potentially significant effects of
GHG emissions and their continued accumulation in the earth’s atmosphere on the global climate. Nor have they developed complete mo dels to represent the anticipated impacts of changes in the global climate on economic resources and the produc tivity with which they are used to generate economic output. As a c onsequence, the estimates of economic damages resulting from increased GHG emi ssions that are generated using integrated models of climate and economic activity exclude some potentially si gnificant sources of costs that are likely to result from increased emissions. As a result, estimates of economic bene fits derived from these models’ estimates of the likely future climat e-related economic damages caused by increased GHG emissions may underestimate the true econo mic value of reducing emissions, although the extent to which they are likely to do so remains unknown.

In the NPRM, NHTSA explained how it accounte d for the economic benefits of reducing CO 2 emissions in this rulemaking, both in developing the proposed CAFE standards and in assessing
the economic benefits of each alternative that wa s considered. The agency noted that the Ninth
Circuit found in CBD v. NHTSA that NHTSA had been arbitrar y and capricious in deciding not to monetize the benefit of reducing CO 2 emissions, stating 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 emi ssions reduction at all. NHTSA ’s discussion in the NPRM of
how it estimated the economic value of reductions in CO 2 emissions received a great deal of attention from commenters, so for the reade r’s benefit, it is largely reproduced below.

To that end, NHTSA reviewed published estima tes of the “social co st of carbon” (SCC) emissions. As noted above, the SCC refers to the marginal cost of additional damages caused by the increase in expected climate impacts resultin g from the emission of each additional metricVIII-29

ton of carbon, which is emitted in the form of CO 2

. 267 It is typically estimated as the net present value of the impact over some extended time pe riod (100 years or longer) of one additional ton of carbon emitted into the atmosphere. Because atmospheric concentrations of greenhouse gases are increasing over time, and the potential damages from global clim ate are believed to increase with higher atmospheric GHG concentrations , the economic damages resulting from an
additional ton of CO 2 emissions are expected to increase ove r time. 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.

NHTSA found substantial variation among differen t authors’ estimates of the SCC, much of
which can be traced to differences in their underlying assumptions about several variables.
These variables include the sensit ivity of global temperatures a nd other climate attributes to increasing atmospheric concentrations of GHGs , discount rates applied to future economic damages from climate change, whether damages su stained by developing regions of the world should be weighted more heavily than damages to developed nations, how long climate changes persist once they occur, and the economi c valuation of specific climate impacts. 268

NHTSA explained that, taken as a whole, recen t 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 res ponse scenarios with low probab ilities but potentially extreme impacts, and may underestimate the climate impa cts and damages that could result from multiple stresses on the global climatic system. At the sa me time, however, many studies do not consider potentially beneficial impacts of climate change , and do not adequately account for how future technological innovations, developm ent patterns, and adaptations could reduce potential impacts from climate change or the economic damages they cause.

Given the uncertainty surrounding estimates of th e SCC, NHTSA suggested that 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. NHTSA c ited the Working Group II’s contribution to the Fourth Assessment Report of the United Nation s Intergovernmental Panel on Climate Change (IPCC) as noting that: The large ranges of SCC are due in large part to differen ces in assumptions regarding climate sensitivity, response lags, the treatm ent of risk and equity, economic and noneconomic impacts, the inclusion of potential ly catastrophic losses, and discount rates. 269

267 Carbon itself accounts for 12/44, or about 27 percent, 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 S CC 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.

268 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, “Perspectives on climate change and sustainability,” 2007, in 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, L.P. Palutikof, P.J. van der Linden and C.E. Hanson, eds., Cambridge Univer sity Press, 2007, at 821-824. Available at http://www.ipcc.ch/ipccreports/ar4- wg2.htm (last accessed March 23, 2009).

269 Climate Change 2007: Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmen tal Panel on Climate Change, at 17. Available at http://www.ipcc.ch/ip ccreports/ar4-wg2.htm (las t accessed March 23, 2009).VIII-30

Although the IPCC is considered au thoritative on the topic of the SCC, it did not recommend a single estimate. However, the IPCC did cite th e Tol (2005) study on four separate occasions as the only available survey of the peer-reviewed lite rature that has itself be en subjected to peer
review. 270 Tol developed a probability function using the SCC estimates of the peer-reviewed literature, which ranged from less than zero to over $200 per metric t on of carbon. In an effort to resolve some of the uncertainty in reported estimates of clim ate damage costs from carbon emissions, Tol (2005) reviewed and summarized 103 estimates of the SCC from 28 published
studies. He concluded that when only peer-reviewed studies publis hed in recognized journals are considered, “...climate change impacts may be very uncertain but it is unlikely that the marginal damage costs of carbon dioxide emissi ons exceed $50 per [metric] ton carbon,” 271 which is about $14 per metric ton of CO 2 . In the NPRM, NHTSA assumed that the summary SCC estimates reported by Tol were denominated in U.S. dollars of the year of his article’s publication, 2005.

NHTSA stated that because of the number of assumptions requi red by each study, the wide range of uncertainty surrounding these assumptions, and their critical infl uence on the resulting estimates of climate damage costs, some st udies have undoubtedly produced estimates of the SCC that are unrealistically high, while others ar e likely to have estimated values that are improbably low. Using a value for the SCC that reflects the central tenden cy of estimates drawn from many studies reduces the chances of relyin g on a single estimate that subsequently proves
to be biased.

It is important to note that the published estimates of the SCC almo st 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 w ithin the U.S. In contrast, the other estimates
of costs and benefits of raisi ng fuel economy standards 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 emi ssions from overseas oil refineries is not counted as a benefit resulting from this rule, because any reducti on in damages to health and property caused by overseas emissions are unlikely to be experienced w ithin the U.S.

In contrast, the reduced value of transfer paym ents from U.S. oil purchasers to foreign oil suppliers that results when lower U.S. oil de mand reduces the world pr ice of petroleum (the reduced “monopsony effect”) is counted as a benefit of reducing fuel use. 272 The agency state that if its analysis were conducte d from a worldwide rather than a U.S. perspective, however, the benefit from reducing air pollution overseas woul d be included, while reduced payments from U.S. oil consumers to foreign suppliers would not.

In the NPRM, NHTSA tentatively concluded that in the interest of analytical consistency, i.e ., in order to be consistent with the agency’s use of exclusively domestic cost s and benefits in prior CAFE rulemakings, the appropriate value to be placed on climate damages caused by carbon
emissions should be the one that reflects the change in damages to the U.S. alone. Accordingly,

270 Id. , at 17, 65, 813, and 822.

271 Tol, Richard S.J., “The marginal damage costs of carbon dioxide emissions: an assessment of the uncertainties,” Energy Policy 33 (2005), 2064-2074, at 2072.

272 The reduction in payments from U.S. oil purchasers to domestic petroleum producers is not included as a benefit, however, since it represents a transfer that occurs entirely within the U.S. economy.VIII-31

NHTSA noted that the value for the benefits of reducing CO 2 emissions might be restricted to the
fraction of those benefits that are likel y to be experienced within the U.S.

Although no estimates are currently available for the be nefits to the U.S. itse lf that are likely to result from reducing CO 2 emissions, NHTSA explained that it e xpected that if such values were developed, the agency would employ those, rather th an global benefit estimates, in its analysis. NHTSA also stated that it anticipat ed 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, NHTSA explained that it elec ted to use the mean value of peer-reviewed estimated global value reported by Tol (2005), whic h was $43 per metric ton of carbon, as an upper bound on the global benefits resulting from reducing each metric ton of U.S. emissions. 273 This value corresponds to approxi mately $12 per metric ton of CO 2 when expressed in 2006 dollars. The Tol (2005) study is cited repeatedly as an authoritative survey in various IPCC reports, which are widely accepted as representi ng the general consensu s in the scientific community on climate change science.

Since Tol’s estimate includes the worldwide costs of potential damages from carbon dioxide emissions, NHTSA elected to employ it as an u pper bound on the estimate va lue of the reduction
in U.S. domestic damage costs that is likely to result from lower CO 2 emissions. 274 NHTSA noted that Tol had a more recent (2007) and inclusive survey published online with peer-review
comments. NHTSA stated that it had elected not to rely on this study, but that it would consider doing so in its analysis for the final rule if the survey had been published, and would also consider any other newly-published evidence.

NHTSA noted that the IPCC Working Group II Four th Assessment Report (2007, at 822) further suggests that the SCC is growing at an annual rate of 2.4 percent, based on estimated increases in damages from future emissions re ported in published studi es. NHTSA also elec ted to apply this growth rate to Tol’s original 2005 estimate . Thus, by 2011, NHTSA estimated that the upper bound on the benefits of reducing CO 2 emissions will have reached about $14 per metric ton of

CO 2 , and will continue to increase by 2.4 percent annually thereafter.

In setting a lower bound, the agency agreed with the IPCC Working Group II report (2007) that “significant warming across the globe and the lo cations of significant observed changes in many systems consistent with warming is very unlikel y to be due solely to natural vari ability of temperatures or natural variability of the systems.” (p. 9) A lthough this finding suggests that the global value of economic benefits from reducing carbon dioxide emissions is unlikely to be zero,

273 $43 per ton of carbon emissions was reported by Tol (at 20 70) as the mean of the “bes t” estimates reported in peer-reviewed studies (at the time). It thus differs from the mean of all estimates reported in the peer-reviewed studies surveyed by Tol. The $43 per ton value was also attributed to Tol by IPCC Working Group II (2007), at

822.

274 For purposes of comparison, NHTSA noted that in the rulemaking to establish CAFE standards for MY 2008-11 light trucks, NRDC recommended a value of $10-$25 per ton of CO 2 emissions reduced by fuel savings, and both EDF and UCS recommended a value of $50 per ton of carbon, which is equivalent to about $14 per ton of CO 2 emissions.VIII-32

NHTSA stated that it does not nece ssarily rule out low or zero valu es for the benefit to the U.S. itself from reducing emissions.

In some of the analysis it performed to deve lop the CAFE standards, NHTSA employed a point estimate for the value of reducing CO 2 emissions. For this estimate, the agency used the midpoint of the range from $0 to $14, or $7.00, per metric ton of CO 2 as the initial value for the year 2011, and assumed that this value would gr ow at 2.4 percent annually thereafter. This estimate was employed for the analyses conducted using the Volpe model to support development of the proposed standards. The agen cy also conducted sensi tivity analyses of the benefits from reducing CO 2 emissions using both the upper ($14/metric ton) and lower ($0/metric ton) bounds of this range.

NHTSA sought comment on its tentative conclusi on for the value of the SCC, the use of a domestic versus a global value fo r the economic benefit of reducing CO 2 emissions, the rate at which the value of the SCC grows over time, the de sirability of and proce dures for incorporating benefits from reducing emi ssions of GHGs other than CO 2 , and any other aspects of developing a reliable SCC value for purposes of establishing CAFE standards.

NHTSA received many comments on its assumpti ons in the NPRM about the SCC. The comment summaries are presented below and grouped by topic: (1) NHTSA’s proposal of a single value for the SCC; (2) NHTSA’s proposal of $7 as the value for the SCC; (3) NHTSA’s proposal of $0 as the lower bound estimate for the domestic U.S. value for the SCC; (4) NHTSA’s proposal of $14 as the upper bound estimate for the domestic U.S. value for the SCC; (5) other values that NHTSA could have proposed for the SCC; (6) NHTSA’s use of a domestic versus a global value for the economic benefit of reducing CO 2 emissions; (7) the rate at which the SCC grows over time; (8) the discount rate that should be used for SCC estimates; and (9) other issues raised by commenters.

(1) NHTSA’s proposal of a single value for the SCC NHTSA received a comment on its proposal of a si ngle value for the SCC from Prof. Gary Yohe,
an economist who has considered the SCC extens ively and whom NHTSA cited in the NPRM.
Prof. Yohe commented that the NPRM had stated that “Using a value for the SCC that reflects the central tendency of estimates drawn from ma ny studies reduces the ch ances of relying on a single estimate that subseque ntly proves to be biased.” 275 Prof. Yohe argued that proposing a single value for the SCC inherently creates bias, because “Any value is based on presumptions about pure rate of time preference, risk and/or inequity aversion, and climate sensitivity.”

(2) NHTSA’s proposal of $7 as the value for the SCC NHTSA received comments from 3 individuals, CARB , the Attorneys General, 10 U.S. Senators, 10 environmental and consumer groups, and the A lliance. Prof. Tol, whose 2005 paper provided

275 73 FR 24414 (May 2, 2008).VIII-33

the basis for NHTSA’s proposal of an SCC number , commented that contrary to NHTSA’s belief that the dollars used in Tol ( 2005) were 2005 dollars, they were in fact 1995 dollars. Prof. Tol
also commented that NHTSA should “alert th e reader” that although Tol (2007) was only “conditionally accepted,” as NHTSA had noted in the NPRM, the newer study “finds larger estimates than the 2005 paper.” Sierra Club et al. , in its comments, also stated that Prof. Tol had commented on the NPRM, arguing that using 19 95 instead of 2005 dollars “would make his 1995 value of $14 closer to a 2005 value of $19.26.”

Several commenters disputed NHTSA’s proposal of $7 as the midpoint between $0 and $14. UCS argued that proposing $7 puts as much we ight on $0 as on $14, even though failing to assign a value was declared by the Ninth Circ uit to be arbitrary and capricious. CBD commented that “NHTSA’s methodology for the selection of an estimate of the value of reducing greenhouse gas emissions is arbitrary and designed to minimize the estimate.” CBD argued that “...simply splitting the differen ce between two points is not a defensible methodology, particularly when the low point of the range is not part of a valid range but simply an arbitrary selection of zero as an endpoint.”

EDF also commented NHTSA’s decision to prop ose $7 because it is th e midpoint between $0 and $14 also “lacks a reasoned basis,” for which “NHTSA fails to provid e any justification.”

The Sierra Club et al. commented that NHTSA is wrong to place “equal weighting and probability” on $0 and $14 and pick the median, and that $7 is “far below current carbon estimates,” citing the 2006 Ster n Review which found an SCC of “on the order of” $85/tonne

CO 2 . The Sierra Club argued that this shows how “misguided and unrealistic NHTSA’s carbon pricing really is.”

The Attorneys General commented that NHTSA’s decision to simply halve Tol’s estimate was “not a reasoned judgment.”

Public Citizen argued that there is no justif ication for using the midpoint, and that NHTSA should instead “weight the credibility of each estimate,” by making “apples to apples” comparisons between the studies by “looking at st udies based on their assumptions.” Public Citizen argued that this will he lp NHTSA avoid skewing the result of averaging estimates from multiple studies. NRDC similarly argued that pr oposing $7 as “a simple average of its proposed upper and lower bounds....assumes a normal distribu tion of damages, which is decidedly not the
distribution of social cost of car bon estimates.” NRDC further argued that “...most social cost of
carbon estimates are biased downwar ds, for the simple reason that almost all models assume perfect substitutability between normal cons umption goods and environmental goods.” NRDC cited 2007 research by Sterner and Persson di saggregating “goods” into “environmental goods” and “consumption goods,” which found that the price of an environmental good like carbon
reductions increased at a fast er rate as damage progresse d than consumption goods would increase. Accordingly, NRDC argued, “NHTSA’s social cost of carbon is much too low.”

Prof. Hanemann also commented that NHTSA did not justify its decision to pick the midpoint (between $0 and $14) and then project it to 2011, although he focused more particularly onVIII-34

NHTSA’s not having applied “the escalation factor of a 2.4 per cent increase in real terms beginning in 2005.”

The Alliance commented that proposing $7 as th e midpoint between $0 and $14 is incorrect. The Alliance argued that NHTSA must try harder to estimate the purely domestic effects of CO 2 emissions reductions, and stated that NERA had found that th e U.S. portion of world gross product “is a much better means of allocating the Un ited States’ share of any benefits in reduced CO2 emissions” than picking the midpoint of a ra nge of global SCC estimates. NERA assumed that the U.S. portion is 20 percent, which “re duces NHTSA’s estimate of CO2 benefits with the ‘optimized standard’ for MY2015 from $869 milli on to $348 million.” NERA also argued that this was conservative, since the U.S., as a deve loped country, should be better able to adapt to negative global warming consequences.

Several commenters also criticized Tol (2005) as being out of date. Pr of. Hanemann made this point, and commented that “more recent analyses show higher damage estimates.” The Attorneys General similarly commented that “It seem s likely that there are be tter estimates” than Tol’s, “Since [that] article is now three year s old, and it itself explains in detail the many deficiencies in the economic literature at that time.” The Attorneys General stated that “NHTSA should consult with EPA on this issue, and cond uct a review of the current scientific and
economics literature.”

Several commenters simply argued that $7/ton is too low a value for the SCC. CARB argued
that “NHTSA’s assumed social cost of carbon in the future is also unreasona bly low, and if set at defensible levels that also properly value cumula tive impacts, could affect the stringency of the standards.” Carin Skoog, an indivi dual, similarly commented that “The arbitrary decision to use $7/ton underestimates the economic, social, and e nvironmental consequences of the impacts of global warming.” ACEEE similarly commente d that NHTSA’s use of $7/ton is both
“inconsistent with current estimates” and “fails to take into account the potentially high probability of a catastrophic climate change situ ation.” The 10 U.S. Senators who commented stated that NHTSA’s value of $7 per ton is “und erestimated,” and “likely to be found arbitrary and capricious.”

(3) NHTSA’s proposal of $0 as the lower bound estimate for the domesti c U.S. value for the
SCC No commenters supported NHTSA’s use of $0/ ton as the lower bound estimate for the U.S. domestic SCC. Several commenters, includi ng UCS, EDF, and Prof. Hanemann cited the IPCC Fourth Assessment Report as evidence that, as Prof. Hanemann stated, “there is no credible evidence of any significant net benefit to the U. S. from the climate change scenarios developed for the Fourth IPCC Report.” The U.S. Senators who commented also stated that in citing the IPCC as not precluding low or zero values to th e U.S., NHTSA had “fail[ed] to recognize that IPCC was looking at global estimates which are not disaggregated.”

Commenters also mentioned other reports as pr oviding evidence that there would be some net adverse impact on the U.S. from climate ch ange, and thus a lower bound value of $0 was
untenable. Prof. Hanemann cite d the recent USCCSP report “conclusively eliminates the notion that climate change is likely to have no net adverse impact on the United States.”VIII-35

UCS argued that proposing $0 as the lower bound “i mplies the possibility that climate change won’t have any negative conseque nces,” which “stands in stark contrast to recent government study findings on U.S. climate change effects and findings from ... the Academies of Science for
the G8+5.”

EDF commented that “A recent review of economi c studies on the predicted impacts of climate change on different economic sectors in the U.S. by the Center for Integrative Environmental Research at the University of Maryland, ‘The US Economic Impacts of Climate Change and the Costs of Inaction: A Review and Assessment,’ also demonstrates the range and scope of adverse impacts that climate change will have on differe nt sectors and regions of the U.S. economy.” EDF stated that “The study conc luded that ‘Scientific evidence is mounting that climate change will directly or indirec tly affect all economic sectors and regions of the country, though not all equally. Although there may be temporary benefits from a changing climate, the costs of climate change rapidly exceed benefits and place major strains on public sector budgets, personal income and job security.’”

Sierra Club et al. commented that “several government repor ts [that] have clearly stated that CO 2 emissions do have a significant impact on our economy.” NHTSA’s conclusion that “it does not necessarily rule out low or zero carbon values fo r the benefit to the U.S. itself from reducing emissions” is arbitrary given agency’s admission that “the global value of economic benefits from reducing carbon dioxide emissions is unlikely to be zero.”

NRDC cited a U.S. government report that “docum ents that many of the projected impacts have already begun,” as well as the St ern Review which “estimated that impacts could result in a loss of 5-20 percent of world GDP by 2100,” a nd its own May 2008 report which “found U.S. damages from four impacts alone w ould cost 1.8 percent of GDP by 2100.”

Several commenters instead raised objections to studies that may show a positive net benefit to the U.S. from climate change, such that a domes tic SCC value could be $0. CBD stated that NHTSA offered “absolutely no evidence to support” proposi ng $0 as the lower bound, and argued that “only one study surveyed in Tol (2 005) included central estimates below $0.00; and that was a non-peer-reviewed arti cle, also authored by Tol.” CBD further argued that Tol (2005) never found, nor included as a consideration in developing SCC estimates, as NHTSA suggested in the NPRM, that any studies failed “to consider pot entially beneficial impacts of climate change,” or to account adequately “for how futu re development patterns and adaptations could reduce potential impacts from climate cha nge or the economic damages they cause.”

Prof. Hanemann also argued that studies suggesting any possible positive net benefit to U.S. from global warming “have serious flaws and ca nnot withstand serious sc rutiny,” and concluded that a value of $0 per ton is “wildly unrealistic” “even [for] a sensitivity analysis.”

NRDC commented that “NHTSA’s lower bound s eems to be based upon the fact that some estimates exist that are zero and even negativ e.” However, NRDC argued that “These lower bound estimates are likely based on outdated scie nce.” NRDC “urge[d] NHTSA to do a rigorousVIII-36

re-examination of Tol’s work, eliminating outdat ed zero estimates and adjusting for fat tailed upper distributions.”

Several commenters also focused on the CBD decision to argue that NHTSA may not use $0 as the lower bound estimate, because as UCS stated, “the Ninth Circuit found a value of $0 to be arbitrary and capricious.” EDF also commented that NHTSA’s decision to pick $0 as the lower bound “lacks a reasoned basis,” given the Ninth Circuit deci sion. Sierra Club et al. and the U.S. Senators similarly commented that $0 as the lower bound is contrary to CBD . The comment by the U.S. Senators stated that “...we can only conclude that the purpose of this ‘low bound’ estimate is to cut the more accurate value in half in an arbitrary manner. We recommend NHTSA remove or justify this low bound es timate in its final CAFE regulation.”

(4) NHTSA’s proposal of $14 as the upper bound estimate for the domestic U.S. value for the
SCC No commenters supported NHTSA’s proposal of $14/ton, based on Tol (2005), as the upper bound estimate for the domestic U.S. value for the SCC. ACEEE argued that “NHTSA’s decision to use Tol’s estimate of $14 as the uppe r bound based on the argument that this value
includes the worldwide costs CO 2 is flawed,” although the co mmenter did not explain why.

Some commenters argued th at NHTSA should not have picked the median from Tol (2005) as its upper bound estimate.

The U.S. Senators who commented stated that NHTSA is wrong to use $14 as the upper bound because Tol’s median is an average of multiple estimates, and averages should be used as averages and not as maximums. The Senators stat ed further that “NHTSA selected the lower of Tol’s two estimates without expl anation.” The U.S. Senators also commented that Tol (2007) updates the previous study and finds a median of over $19/ton. NRDC also cited Tol (2007) as reflecting an increase in the median from $14 to $20 dollars per ton of CO 2

.

Sierra Club et al. commented that $14 is an incorrect “maximum,” because the maximum that
Tol “states that the maximum carbon value is in the range of $55-$95 per metric ton CO2.” The commenter further argued that if NHTSA could justify $0 as th e lower bound, “then it should not
be able to rule out the high value of $95 per ton CO 2 in the study, and the average value would be much higher.”

NRDC commented that NHTSA should not have used Tol’s median value of $14 as its upper bound for two reasons. First, a median value is not properly reflective of climate change damage estimate distributions, which are “asymmetric” with “fat” upper tails. And second, because of the unique aspects of climate change damage estim ates, such as “nonlinearities, abrupt change, and thresholds,” “a full probability density function should be estimated, using the full range of all [SCC] estimates from the studies, not simply a collection of their ‘best-guesses.’” [Emphasis in original.] NRDC argued that research has shown that “When the same traditional social cost of carbon analyses are rerun inco rporating the potential for nonlinear change, the resulting policy conclusions are changed considerably to greate r mitigation,” and that “Another recent study has shown that incorporating the potential for low-pr obability, high-damage events can increase the social cost of carbon by a factor of 20.”VIII-37

NRDC also cited Prof. Weitzman to argue that the complications of climate change damage estimates require any analysis to weigh more heavily the “low probability/high catastrophic risks,” because these will othe rwise be insufficiently account ed for. In discussing the
uncertainties associated with climate cha nge, NRDC cited Weitzman as stating that
The result of this immense cas cading of huge uncertainties is a “reduced form” of truly stupendous uncertainty about the aggregate- utility impacts of catastrophic climate change, which mathematically is represente d by a very-spread-out very-fat-tailed PDF [probability density function] of what might be called (present discounted) “welfare sensitivity”...[T]he value of “welfare sens itivity” is effectively bounded only by some

very big number representing something like the value of statistical civilization as we know it or maybe even the value of stat istical life on earth as we know it.

Thus, NRDC argued, using an upper bound of $14 ca nnot possibly account fo r the uncertainties and risk of climate change. Like Sierra Club et al ., NRDC further argued th at “...for consistency with the rationale used for proposing the lower bound, NHTSA’s upper bound should be based upon some function of the highest estimates in the Tol 2005 study (the very highest was $1,666).”

Some commenters argued that NHTSA had overlooked particular aspects of the Tol (2005) study, and thus arrived at $14 incorrectly.

CBD argued that NHTSA overlooked key aspects of the Tol (2005) analysis in proposing $14 per ton, including the fact that Tol included signif icantly higher estimates in his analysis. EDF similarly commented that NHTSA had failed to “discuss the significant gaps in the existing research reviewed in [Tol (2005)] and focuse[d] on a specific estimate of the SCC that is biased
toward lower value estimates.” EDF stated th at NHTSA’s decision to use only peer-reviewed studies from Tol (2005) introduced particular bi as, because those studies “systematically used higher discount rates...which may have biased their results downw ard” compared to averaging all the studies together.

Some commenters argued that Tol (2005) was flawed to the point that it could not provide a
reliable basis for NHTSA to use its median estimate as the upper bound.

CBD commented that “the studies cited in the Tol (2005) survey da ted back as much as 18 years, to 1991, and 25 of the 28 studies cited were publishe d more than five years ago,” so given that climate change science is progr essing very rapidly, these studies are probably outdated.

EDF also argued that “Most of th e 28 studies surveyed by Tol” are outdated and “consider only a limited number of potential impacts from climate ch ange,” as Tol recognizes by cautioning that the estimates analyzed “may understate the true co st of climate change.” EDF stated that the IPCC’s “most recent compilation of SCC research ” agrees. EDF also commented that Tol’s meta-analysis “compares studies with widely different methodologies and assumptions,” particularly discount rates, wh ich EDF stated NHTSA should have controlled for because it “can have a considerable impact on SCC estimates.”VIII-38

NRDC criticized Tol (2005) extens ively in its comments. NRDC stated that Tol’s estimate was based on studies which exclude (1) “non-market co sts, such as damage to and loss of entire ecosystems and species;” and (2) “studies of national security costs caused by conflicts over stressed resources and increased migration from heavily impacted areas,” which “describe global warming as a ‘threat multiplier.’” NRDC recogni zed that Tol acknowledged that “costs such as those described above are poorly accounted for in current social cost of carbon estimates,” but
insisted that NHTSA must nonetheless account for them.

NRDC also argued that Tol’s estimate is based on outdated studies, beca use “there are smaller natural sinks for carbon than Tol assumed, hi gher emissions than he assumed, a higher temperature response to emissions than he assume d, and faster changes in observed impacts than
he assumed.” NRDC commented that recent even ts like Hurricane Katrina are evidence that the U.S. cannot adapt to climate change-related disa sters as fast as prev iously thought. NRDC
further commented that it was unclear whether To l’s estimate “included any valuation for lost lives,” suggesting that including this valuation could raise SCC considerably, and arguing that EPA accounts for it in Clean Air Act rulemakings.

(5) Other values that NHTSA could have chosen for the SCC Many commenters suggested other SCC values that they thought NHTSA should use instead of a value based on Tol (2005).

Several commenters mentioned SCC values produced by EPA. In March 2008, EPA produced an analysis for the Senate Committee on Enviro nment and Public Works for S. 2191, “America’s Climate Security Act,” also known as the Lieberman-Warner bill. 276 Public Citizen commented that NHTSA’s upper bound estimate should be at least as high as EPA’s estimates for the Lieberman-Warner bill, which Public Citizen said “are more recent than the Tol estimate cited in
NHTSA’s notice.” Public Citizen commented that EPA “estimated the value of CO 2 in 2015 between $22 and $40 per metric ton of CO 2 , and cited two other analys es with higher estimates of $48 and $50 per metric ton CO 2 .” Sierra Club et al. also commented that NHTSA must use a higher SCC value, and stated that “EPA’s recent analysis of America’s Climate Security Act of
2007 noted that the value of a ton of CO2 could be as high as $22-$40.28.” An individual, Carin Skoog, also commented that “The US EPA recently suggested the value of a ton of CO2 could be as high as $22-35.” ACEEE appeared to refer obliquely to the EPA estimates, recommending that NHTSA use a higher CO 2 estimate. ACEEE argued that “legislative efforts to implement a carbon regime in which the projected market cost of CO 2 is expected to lie between $20 and $30 – significantly higher than the average damage cost assumed by NHTSA – serves as evidence that the U.S. is now beginning to contemplate the high risk of rising greenhouse gas emissions.”

NRDC commented that NHTSA cited “compliance cost estimates provided by NRDC and others in the 2006 light truck rulemaking” in descri bing its proposal of the upper bound estimate. NRDC argued that NHTSA should instead consid er damage costs and not rely on compliance
cost estimates. NRDC stated th at “If NHTSA were to consider compliance costs it must consider current analyses, such as EPA’s analysis of S.2191, which finds that CO 2 allowances would cost

276 Available at http://www.epa.gov/climatechange/downloads/s 2191_EPA_Analysis.pdf (last accessed March 23, 2009).VIII-39

19 to 67 (2005) dollars per ton of CO 2 -equivalent in 2012 rising at 5 percent per year real (the range for EPA’s Core Scenario is $19 to $35 in 2012, rising at 5 percent per year real).”

EPA also recently released a “Technical Support Document on the Benefits of Reducing GHG Emissions,” 277 (TSD) to accompany an Advance Noti ce of Proposed Rulemaking (ANPRM) on regulating GHG emissions under the Clean Air Act. 278 EDF commented in its original comments that “The higher SCC estimates contained in EPA's draft ANPR, and EPA’s accompanying discussion of the remaining omissi ons and weaknesses in state-of-the-art SCC research, further demonstrates that NHTSA's estimates are underestimating the benefits of reducing carbon dioxide emissions, a nd therefore setting CAFE standa rds below optimal levels.” After the TSD was released, EDF submitted it to NHTSA’s NPRM docket, and submitted late additional comments arguing that NHTSA must “adjust its fina l rulemaking action in accordance with EPA’s assessment and findings,” because “EPA's assessment is far more rigorous than NHTSA's proposal, and EPA's determinations are supported by a considerable and well-reasoned
volume of information.” EDF st ated that EPA did its own me ta-analysis “building on” Tol (2005) and (2007), but including “only recent peer reviewed studies that met a range of quality
criteria in its evaluation.” EDF further stated that EPA a rrived at an estimate of $40/tCO 2 (using a 3 percent discount rate), or $60/tCO 2 (using a 2 percent discount ra te). EDF commented that
EPA concluded that estimates “ likely underestimate costs of carbon dioxide emissions,” because they do not account for all the climate change im pacts identified by the IPCC, like “non-market damages, the effects of climate variability, risks of potential extreme weather, socially contingent events [(such as violent conflict)], a nd potential long-term catastrophic events.”

The U.S. Senators who commented argued that NHTSA’s use of $14/ton based on Tol (2005) as the “high bound” estimate was incorrect becaus e EPA had been working since 2007 “to develop more accurate, ‘state-of-the-art’ estimates of th e benefits of reducing greenhouse gas pollution.” The Senators stated that “Although EPA’s estimates have not been finalized, the Agency used $40 per ton as the value of reduci ng carbon dioxide emissions.” The Senators further stated that “NHTSA’s draft rule inexplicably makes no mention of EPA’s extens ive research and analysis in
this area.”

Other commenters argued that NHT SA should have used or considered the value at which CO 2 allowances are currently trading in the EU regulatory system. UCS stated that using $14 as the upper end is “unacceptably low,” given that “The European Climate Exchange, which provides a futures market value for global warming pollution in Europe’s carbon constrained market,
indicates 2011 contracts for car bon dioxide at approximately $45 (U.S.) per metric ton—well above the figure cited by NHTSA.” UCS argue d that “This value represents a predicted marginal abatement cost (the cost of avoidi ng global warming pollution), and is likely a
conservative estimate of the benefit of reduci ng global warming since the cost of avoiding climate change is lower than the cost of fixing the damage after it occurs.” UCS further argued that this number is also “generally consistent wi th other recent allowance price estimates, such as the EPA’s assessment of GHG allowance prices under Lieberman-Warner: $22-$40 in 2015 and $28-$51 in 2020 (EPA figures are in 2005 dollars per ton of CO 2 -equivalent.)”

277 Available at Docket No. NHTSA-2008-0089-0456.2.

278 EPA’s ANPRM was signed July 11, 2008, after NHTSA’s NPRM was published. See 73 FR 44353 (July 30, 2008).VIII-40

Sierra Club et al. , Public Citizen, and CARB all also commented that NHTSA’s value for the SCC is too low, and that NHTSA should instead use a CO 2 damage value based on the market value in the European Trading System, either the current value (which Public Citizen stated was “recently... around €30 per allowance (one metric ton CO 2 equivalent),” and CARB stated was “currently trading around $42 pe r ton”), or some future value. Sierra Club et al . argued that “the
futures market value for a metric ton of CO 2 in 2011 is already up to $45,” while CARB went on to argue that “...Germany Deutsche Bank [is] forecasting EUA prices of $60 for 2008 and EUA prices as high as $100 by 2020 [citation removed].”

Other commenters suggested other SCC values di fferent from any discussed so far. For example, Prof. Hanemann argued that, based on hi s own research, NHTSA use a value of “about $25 per metric ton [of CO 2 ] in 2005$,” and should apply a real growth rate of 2.4 percent per year to determine the value of reducing emissi ons in future years. CARB, in contrast,
commented that “NHTSA should also consider us ing substantially higher estimates.” CARB
stated that “the Internationa l Energy Agency (IEA) recently es timated that to limit global CO 2 emissions by the 50 percent GHG reduction that th e IPCC concluded is needed to keep global temperatures from rising more than two degrees Celsius by 2050, CO 2 offset prices will need to rise to up to $200 per ton....” CA RB further argued that “...even this higher market price for carbon may not incorporate the true cost of all natural resource s damages, an externality.”

Mr. Montgomery commented that NHTSA should use an SCC value of $0, because he argued that “If a comprehensive cap on [CO 2 ] emissions is put in plac e, as many commentators and policymakers predict, then the choice of policy instrument will have no effect on the overall level of emissions,” such that “Tightening a CAFE sta ndard will only result in greater mitigation in emissions from [motor vehicles] and less mitigation in parts of the economy where decisions are made in response to carbon prices without specific regulatory mandates.” Thus, Mr. Montgomery concluded that “the damages from global warming will be the same no matter what the level of the CAFE standard, so that the SCC used should be zero.”

Mr. Montgomery also commented that an SCC ba sed on Tol’s estimates will be too high if the “global policy objective toward greenhouse gas emissions...is a lower concentration than that on
which the Tol estimates are based.” Mr. Mont gomery argued that “Marginal damages depend on the level of GHG concentrations at which they are measured,” so that “If the goal for global
concentrations is se t at a high level ( e.g. , 750 ppm) then damages from an additional ton of CO 2 (due to higher concentrations dur ing the period of its residence in the atmosphere) will be higher than if the goal is set at a low level ( 350 ppm) at which point most of the damaging consequences have been eliminated.”

Ford redacted much of its discussion of the SCC based on confidentiality concerns, but seemed to argue generally that reducing CO 2 emissions from motor vehicles is expensive compared to reducing emissions in other sect ors, and commented that “All sectors must contribute” to reducing emissions. Ford “recomme nded that NHTSA consider using CO 2 mitigation cost in their analysis in lieu of emission damage cost.”VIII-41

NADA commented that “NHTSA sh ould consider incorporating in to its analysis the $2.97 per metric ton recently paid by the U.S. Hous e of Representatives for carbon offsets.” 279

The Alliance was the only commenter to suggest that NHTSA not quantify the SCC at all. The Alliance argued that “...given the fact that no published studies of which we are aware address the SCC apportionment issue, NHTSA would be well w ithin its rights to decide that SCC will be considered purely in a qualitative balancing fashion and not quantified.” The Alliance cited Transmission Access Policy Study Group v. FERC , 225 F.3d 667, 736 (D.C. Cir. 2000) (“Given that FERC’s comparison of the frozen efficiency cas e to its base case yielded little difference, the agency had no reason to conduct further analysis. By rigorously examining the frozen efficiency case, even though it believed the case to be unr easonable, FERC ensured that its decision was ‘fully informed’ and ‘well-considered.’”).

(6) NHTSA’s use of a domestic versus a global value for the economic benefit of reducing CO 2 emissions NHTSA received a number of comments on its tentative decision to employ a domestic value for the SCC instead of a global value. Several co mmenters supported a domestic value, while other commenters supported a global value.

The Alliance argued that NHTSA must consider only domestic impacts both because of EPCA,
which refers to “the need of the United States to conserve energy,” and because of the “extraterritoriality” or “ Aramco canon,” see EEOC v. Arabian American Oil Co. , 499 U.S. 244, 260 (1991) (“It is a longst anding principle of American law ‘t hat legislation of Congress, unless a contrary intent appears, is meant to apply onl y within the territorial jurisdiction of the United States.’) (quoting Foley Bros. v. Filardo , 336 U.S. 281, 285 (1949)). The Alliance further argued that because NHTSA must consider only domestic impacts, it must “develop some mechanism for scaling down the global SCC esti mates produced in the p ublished literature,” besides NHTSA’s proposal which just took the midpoint between $0 and $14 as the domestic SCC value. The Alliance argued that it would be inappropriate to use land mass to determine the domestic portion, since so much of the land ma ss on the planet is uninh abited; and also argued that it would be inappropriate to use population, since “not all human beings live in areas that are expected to be equally impacted by climate change.” As discusse d above, the Alliance cited to the NERA Report that it included with its commen ts as having found that an SCC value based on the U.S. share of world gross product was more appropriate.

NADA similarly commented that “NHTSA should account only for any domestic impacts of reducing the social costs of motor vehicle CO 2 , given that EPCA focuses on U.S. energy security
and all other costs and benefits evaluated with respect to the proposed CAFE standards are domestic only.”

Mr. Delucchi agreed with NHTSA’s discussion that “consistency requires” that only U.S. domestic “global warming damages” be consid ered if NHTSA also accounts for the monopsony effect in the reduced value of transfer payments from U.S. oil purchasers to foreign oil suppliers.

279 NADA cited the “Statement of Daniel P. Beard, Chie f Administrative Officer, U.S. House of Representatives, Concerning the Purchase of Carbon Offsets,” which does not list the specific price paid for the offsets described.
Available at http://cao.house.gov/pre ss/cao-20080205.shtml (las t accessed March 23, 2009).VIII-42

Mr. Delucchi suggested that NHTSA use a procedure de scribed in his previous research to estimate the fraction of global damages from climat e change that would be borne within the U.S., and apply this fraction to the estimated global SCC to determine the value of U.S. domestic benefits from reducing emissions. This proced ure adjusts the fraction of global GDP accounted for by the U.S. by the relative sensitivity of the U.S. to climate damages compared to the remainder of the world, which Delucchi measur es by the ratio of U.S. dollar damages from climate change per dollar of U.S. GDP to gl obal economic damages from climate change per dollar of global GDP. Using this method, he estimates that U.S. damages from climate change are likely to represent 0-14 percent of total global damages, and thus that the value to the U.S. of reducing carbon emissions is equal to that same pe rcentage of the estimated global value of the

SCC. 280

Mr. Montgomery argued that a domestic SCC value was appropriate, commenting that “U.S. policy should be based on marginal damages to the U.S. from CO 2 emissions in the U.S., as
stated in relevant OMB circular s on cost-benefit analysis and suggested in the draft.” Mr. Montgomery further stated that “The consensus appears to be that ri cher countries are less vulnerable than poorer, and that te mperature increases will be leas t in temperate regions like the U.S.” Thus, Mr. Montgomery argued that a conser vative estimate of U.S. damages would be a
calculation “based on the ration of U.S. GDP to world GDP.”

Other commenters argued that NHTSA should use a global SCC value. NRDC commented that because “Carbon dioxide is a global pollutant, and much of the damages other countries will experience are a result of U.S. emissions,” and because “emissions in other countries will cause damages in the U.S.,” that “It is fundamentally inconsistent with the gl obal circulation of these pollutants to arbitrarily limit a ssessment of the benefits of re ducing U.S. emissions to those accruing in our own territory.” NRDC also comment ed that national security studies show that the global social costs of carbon wi ll “spill over” to the U.S. a nd other wealthy countries. EDF also commented that NHTSA should use a glob al SCC number rather than a domestic one, because “Climate change is clearly a global issu e,” so EDF “recommend[s] that benefits of reducing CO 2 concentrations should reflect be nefits to society as a whole.”

EDF and the U.S. Senators commented that use of a global SCC value would be consistent with OMB guidance that international impacts of regula tions may be considered if appropriate. The
Senators also commented that the U.S. must cons ider the global climate change effects of its regulations because it ratified the United Nations Framework C onvention on Climate Change in 1992. If every nation considers only domestic e ffects of climate change , the Senators argued, emissions reduction policies wi ll fall “far short of the socially optimized level.”

CBD similarly commented that NHTSA should use a global value for CO 2 , arguing that using $7 “fails to incorporate the full economic costs of gl obal climate change, values that are difficult to monetize, and costs to the world outside the boundaries of the Unite d States.” CBD stated that “In general, the estimate of the social costs of climate change fails to incorporate the loss of

280 Mark A. Delucchi, Summary of the Non-Monetary Ex ternalities of Motor Vehicle Use, UCD-ITS-RR-96-3 (9) rev.1, Institute of Transpor tation Studies, University of California, Da vis, originally published September 1998, revised October 2004. Available at http://www.its.ucd avis.edu/publications/2004/UCD-ITS-RR-96-03(09)_rev1.pdf (last accessed March 23, 2009).VIII-43

biodiversity, complex and large-scale ecosystem services, and the dispr oportionate impacts of global climate change on the developing world.” CBD also stated that NHTSA’s use of $0 as the lower bound estimate is “[p]resumably ... meant to imply that the United States might benefit economically by letting other countries bear th e costs of unabated American greenhouse gas emissions. Setting aside the tremendous ethi cal implications of such a position, NHTSA provides absolutely no evid ence to support the claim.”

In its late comments accompanying its submissi on of EPA’s TSD, EDF argued that EPA’s TSD concluded that a global number is correct, for several reas ons. Because GHGs are global pollutants and affect everyone, using “domestic only” estimates would “omit potential impacts on the United States ( e.g. , economic or national security impact s) resulting from climate change impacts in other countries.” Consequently, a gl obal number must be used to avoid missing any benefits and to maximize global net benefits ( i.e. , “countries would need to mitigate up to the point where their domestic marginal cost equals the global marginal benefit.” EDF stated that EPA’s TSD cites Nordhaus (2006), a nd says that “Net present valu e estimates of global marginal benefits internalize the global and intergeneratio nal externalities of reducing a unit of emissions and can therefore help guide policies towards an efficient level of provision of the public good.”

(7) The rate at which the SCC grows over time
Several commenters cited the IPCC Fourth Assessmen t Report with regard to the rate at which
the SCC should increase over time. CBD commente d that as part of the Fourth Assessment Report, the IPCC “...states that ‘It is virtually certa in that the real social cost of carbon and other greenhouse gases will increase over time; it is very lik ely that the rate of increase will be 2% to 4% per year.’” The U.S. Senators commented th at the 2.4 percent per year increase that NHTSA used in the NPRM is incorrect, because “the IPCC repor t states that ‘it is very likely that the rate of increase will be 2% to 4% per year.’”

EDF stated that IPCC’s recommendation of a 2.4 pe rcent growth rate was meant to be used in combination with a low, intergenerational discount rate. EDF further argued that after the Fourth Assessment Report was released, one of the lead authors recommended using a growth rate of 3 percent, but that “The OMB equivalent guida nce for the UK ... recommend using a 2 percent yearly increase.” EDF thus c oncluded that the 2.4 percent grow th rate could be used, but only with a maximum 3 percent discount rate, and argued that a range of growth rates should be run in the sensitivity analysis “because of considerable uncertainty.”

(8) The discount rate that should be used for SCC estimates Commenters urged NHTSA to consider a low or even negative discount rate in choosing an estimate for the SCC. CBD, for example, stated that Stern found that “‘If consumption falls along a path, the discount rate can be negative. If inequality rise s over time, this would work to reduce the discount rate, for the so cial welfare functions typically used. If uncertainty rises as
outcomes further into the future are contemplated, this would wo rk to reduce the discount rate, with the welfare functions typically used.’” CBD then argued that “A negative discount rate would dramatically increase the co st of climate change in the cost-benefit analyses in the proposed rule.”VIII-44

NRDC commented that NHTSA should use a discount rate of no more than 3 percent for the entire rulemaking, and returned to this argument in its SCC discussion, criticizing Tol’s estimate for relying “primarily upon estimates that did not use current accepted climate change discounting procedures of a dec lining discount rate over time.”

In its initial comments, EDF stat ed that NHTSA should only consider recent studies that use a 3 percent discount rate for estimating SCC. In its late comments, EDF stated that EPA’s TSD
concluded that “a low discount rate is most appropriate for SCC es timation,” for several reasons. First, because OMB Circular A-4 allows agencies to use a lower discount rate when there are inter-generational benefits associated with a rulemaking. Second, because “In this intergenerational context, a three percen t discount rate is consistent w ith observed interest rates from long-term intra-generational investments (net of risk premiums) as well as interest rates relevant for monetary estimates of the impacts of climate change that are primarily consumption effects.” Third, because EPA had found that the scientific lite rature supports the use of a discount rate of 3 percent or lower, as being “...more consiste nt with conditions asso ciated with long-run uncertainty in economic growth and interest rates, intergenerational considerations, and the risk of high impact climate damages (which c ould reduce or reverse economic growth).”

(9) Other issues raised by commenters The remaining issues raised by commenters w ith regard to NHTSA’s proposal regarding the
value for the SCC were as follows:

Public Citizen commented that NHTSA should also have considered “the costs of inaction on reducing greenhouse gas emissions and the resu ltant consequences of global warming,” including other environmental and health conse quences such as those analyzed in NHTSA’s DEIS. Public Citizen cited EPA’s denial of California’s waiver request and “a recent report from the University of Maryland” as evidence of some of these costs, and argued that NHTSA needed
to estimate “the costs of inactio n” in making its final decision.

NRDC commented that emissions reductions may be “greater than what CAFE accomplishes,” such that the U.S. would “get...a larger social co st of carbon benefits stream,” if the U.S. actions in “taking a lead in reducing em issions... [helps to] induce other countries, especially China and India, to also reduce.” NRDC al so argued that “Carbon dioxide has a very slow decay rate in the atmosphere, lasting hundreds of years into the fu ture,” which means that “the social costs of carbon extend well past the life time of the vehicle.” Thus, “Any se nsible benefits stream would
extend them at least several decades past the lifetime of a vehicle.”

In its original comments, EDF argued that NHTSA should have considered using a riskmanagement framework in developing an SCC estimate, because cost-b enefit analysis “cannot capture the range of uncertainty and risk that characterizes climate change.” EDF cited Prof. Weitzman’s work as highlighting “that the expected damages of climate change may be dominated by the existence of consequences wh ich have very low proba bility but very high damages (such as double-digit increases in mean global temperature), or a ‘fat tail’ in the distribution of possible outcomes.” In its la te comments, EDF added that EPA’s TSD also suggested that a risk assessment framework may be more appropriate than cost-benefit analysis “in light of the ethical implicati ons of climate change and the difficulty in valuing catastrophicVIII-45

risks to future generations.” The TSD went on to say that “Economics alone cannot answer the questions, policy, legal, ethical c onsiderations are relevant too, and many cannot be quantified. When there is much uncertainty, economics recommends a risk management framework for guiding policy.”

Agency response: In determining its response s to the public comments on the value of reducing CO 2 emissions, the agency was mindful that the 9 th Circuit remanded rulemaking to NHTSA “for it to include a
monetized value for this benefit [the reduced risk of global wa rming as a result of reducing CO 2 emissions] in its analysis of the proper CAFE standards.” 281 (Emphasis added.) NHTSA
understands this direc tive to require the agency to include within its mode ling, with at least some level of specificity, actual values for the SCC. Further, as in the case of other public comments, the agency is required by the Administrative Procedure Act to respond to the relevant and significant public comments, incl uding those central to the agen cy’s decision on standards under EPCA, in a manner reflecting consider ation of the relevant factors.

As noted above, in the NPRM, we tentatively selected the mean value ($14) in Tol (2005) as a global value, and announced plans to attempt to develop and possibly use a domestic value for
the final rule. For most of th e analysis it performed to develo p the proposed standards using the Volpe CAFE model, NHTSA used a single es timate for a domestic value of reducing CO 2 emissions. The agency thus elected to use th e midpoint of the range from $0 to $14 (or $7.00) per metric ton of CO 2 as the initial value fo r the year 2011, and assumed that this value would grow at 2.4 percent annually ther eafter. This estimate was employed for the analyses conducted using the Volpe CAFE model to support development of the propos ed standards. The agency also conducted sensitivity analyses of the benefits from reducing CO 2 emissions using both the upper ($14 per metric ton, since the domestic value could not exceed the global one) and lower ($0 per metric ton) bounds of this range.

After considering comments on the approach it employed in the NPRM and more recent estimates of the SCC, NHTSA has decided to employ a range of estimat es for the value of reducing GHG emissions in the analysis it perfor med to support this Final Rule for MY 2011 as
discussed in further detail belo w. To do so, the agency identif ied a range of estimates from current peer-reviewed estimates of the value of the SCC, and then tested the sensitivity of alternative CAFE standards to this range of uncertainty while hol ding the other economic parameters used in its analysis fixed at their estimated values. The range of estimates, which the agency believes fairly represents the uncertainty surrounding the value of th e SCC, consists of a domestic value ($2) at the lower end, a global va lue ($33) equal to the mean value in Tol (2008) and a global value ($80) one sta ndard deviation above the mean value. NHTSA believes that, based on currently available information and anal ysis, $2 is a reasonable domestic value and $33 is a reasonable global value, but notes the uncertainty regarding bot h values. The agency tested the sensitivity of alternative CAFE standards to this range of uncertainty while holding the other economic parameters used in its analysis fixed at their estimated values.

On the basis of this analysis, the agency has concluded that its adopted standards for MY 2011
are not sensitive to the alternative estimates of the value of reducing CO 2 emissions, so although

281 CBD, 508 F.3d 508, 535.VIII-46

it has selected global and domestic values for the SCC for use in analyzing the effects of
different SCC values on the standards in this one-year rulemaking, NHTSA believes that is not necessary for purposes of this rulemaking to make definitive, long term choices about the most appropriate global or domestic va lue or to choose between using a global versus domestic value. This approach is sufficient for this rulemaking and will allow efforts to make more specific
choices to be deferred until additional scientif ic and economic evidence can be accumulated, and the participation of other federal agencies in those efforts can enable the development of a consistent estimate for use in those agencies’ re spective regulatory and policy-making activities, including the next CAFE rulemaking.

The agency is well aware that scientific and economic knowledge about th e contribution of GHG emissions to changes in the future global climate and the potential resulting damages to the world economy continues to evolve rapidly. Thus, any value placed in this rulemaking on reducing CO 2 emissions is subject to likely change . NHTSA recognizes the importance of continuing to monitor current research on the potential economic damages resulting from climate change, and of periodically updating es timates of the value of reducing CO 2 emissions to reflect continuing advances in scientific and economic know ledge about the nature and extent of climate change and the threat it poses to world economic development. NHTSA recognizes the interest and expertise of other federal ag encies, particularly EPA and DOE, in the issue of valuing the reductions in climate damages that are likely to result from those agencies’ own efforts to reduce
GHG emissions. NHTSA will continue to work clos ely with those and other federal agencies in the development and review of the economic valu es of reducing GHG emissions that it plans to employ in its next CAFE rulemaking.

Global value of reducing CO 2 emissions To develop a range of estimates that accurately reflects the un certainty surrounding the value of reducing emissions, NHTSA relied on Tol’s (2 008) expanded and updated survey of 211 estimates of the global SCC, which was publishe d after the agency completed the analysis it conducted to develop its proposed CAFE standards. 282 Tol’s 2008 survey encompasses a larger number of estimates for the global value of reducing carbon emissions than its previouslypublished counterpart, Tol (2005), a nd continues to represent the only recent, publicly-available compendium of peer-reviewed estimates of th e SCC that has itself been peer-reviewed and published. The wide range of estim ates it includes reflects thei r authors’ varying assumptions about critical parameters that affect the S CC, including the sensitivity of the global climate system to increasing atmospheric concentrations of CO 2 and other GHGs, the extent of economic damages likely to result from climate change, the rate at which to discount future damages, the relative valuation of climate damages likely to be sustained by nations with different income levels, and the degree of collective aversion to the risk of extreme climate change and the resulting potential for equally extreme economic damages. NHTSA believes that Tol’s updated survey provides a reliable and cons istent current basis for establis hing a range of plausible values for reducing CO 2 emissions from fuel production and use.

Tol’s updated survey includes 125 estimates of the SCC published in peer-reviewed journals through the year 2006. Each of thes e represents an independent es timate of the world-wide value

282 Richard S.J. Tol (2008), The social cost of carbon: trends, outliers, and catastrophes, Economics -- the OpenAccess, Open-Assessment E-Journal , 2 (25), 1-24.VIII-47

of increased economic damages from global climate change that would be likely to result from a small increase in carbon emissions, and by imp lication, the global valu e of the reduction in future economic damages from climate change that would result from an incremental decline in GHG emissions. Tol reports that the mean valu e of these estimates is $71 per ton of carbon emissions, and that the standard deviation of th is estimate – a measure of how much a typical estimate differs from their average value – is $98 pe r ton; the fact that this latter measure is significantly larger than the mean value indicate s the broad range spanned by the estimates.

NHTSA staff confirmed in conversations with th e author that these values apply to carbon emissions occurring during the mid-1990s time fra me, and are expressed in approximately 1995
dollars. 283 The $71 mean value of the social cost of increased carbon emissions reported by Tol corresponds to a global value of $19 per metric ton of CO 2 emissions reduced or avoided when expressed in 1995 dollars, while the $98 standard deviation for carbon emissions corresponds to $27 per ton of CO 2

. 284 Adjusted to reflect increases sin ce the mid-1990s in the marginal damage costs of emissions at now-higher atmospheric concentrations of GHGs, and expressed in 2007 dollars, Tol’s mean value corresponds to a global damage cost of $33 per ton of CO 2 emitted during the year 2007, with a standard deviation of nearly $47 per ton. Thus, the value that is one
standard deviation above the $33 figure is $80 per ton of CO 2

.

Many commenters noted that some recent estimates of the SCC are significantly higher that those reported by Tol (2005), a nd suggested that NHTSA employ these higher estimates of the SCC to determine the value of reducing CO 2 emissions. Specifically, commenters highlighted the widely-cited Stern Review’s estimate that the current SCC is likely to be in excess of $300 per metric ton of carbon, or approximately $80 per ton of CO 2

. 285 Some commenters argued that Stern’s estimate should be given substantial weight in determ ining the value of reducing CO 2 emissions used to develop the agency’s final CAFE standards. Although Stern’s estimate is reported in Tol’s 2008 survey, it is not included in the estimates that form the basis for NHTSA’s revised range of values, because Stern’s study has not yet been subjected to formal peer review.

NHTSA notes that the Stern Report’s estimate of the SCC employs a low value for the discount rate it applies to future economic damages from climate change, and that this assumption is largely responsible for its high estimate of the SCC. Hope and Newbury demonstrate that substituting a more conventional di scount rate would reduce Stern’s es timate of the benefits from reducing emissions to the ra nge of $20-25 per ton of CO 2 , which is well within the range of other

283 Tol (2008), Table 1, p. 16.

284 As noted in an earlier footnote, carbon itself accounts fo r 12/44, or about 27 percent, of the mass of carbon dioxide (12/44 is the ratio of the mol ecular weight of carbon to that of ca rbon dioxide). Thus , each ton of carbon emitted is associated with 44/12, or 3.67, tons of car bon 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.

285 Stern, N.H., S.Peters, V.Bakhshi, A.Bowen, C.Cameron, S.Catovsky, D.Crane, S.Cruickshank, S.Dietz, N.Edmonson, S.-L.Garbett, L.Hamid, G.Hoffman, D.Ingram, B.Jones, N.Patmore, H.Radcliffe, R.Sathiyarajah, M.Stock, C.Taylor, T.Vernon, H.Wanjie, and D.Zenghelis (2006), Stern Review: The Economics of Climate Change Cambridge University Press, Cambridge, England.VIII-48

estimates summarized in Tol’ s 2008 survey, and significantly below the $33 equivalent of the mean of peer-reviewed estimates Tol reports. 286

Other commenters noted that EPA has recently deve loped preliminary estimates of the value of reducing CO 2 emissions, and recommended that NHTSA em ploy these values in its analysis of
alternative CAFE standards. EPA’s estimates are reported in that ag ency’s Technical Support Document on Benefits of Reducing GHG Emi ssions (GHG Benefits TSD) accompanying its Advance Notice of Proposed Rulemaking on motor vehicle CO 2 emissions. 287 In that document, EPA derives estimates of the SCC using the subs et of estimates includ ed in Tol’s 2008 survey drawn from peer-reviewed studies published after 1995 that do not employ so-called equity weighting. 288 Updated from their original mid-1990s valu es to reflect increases in the marginal damage costs of emissions at growin g atmospheric concentrations of CO 2 and expressed in 2006 dollars, EPA reports average values of $40 per ton of CO 2 for studies using a 3 percent discount rate, and $68 per ton for studies using a 2 percent discount rate. 289 (The discount rates employed in developing the 125 peer-reviewed estimates surveyed by Tol ranged from 1 to 10 percent. 290 )

NHTSA recognizes that in a recent rulemaking, DOE used a range of values from $0 to $20 (in 2007 dollars) per ton to estimate th e benefits of reductions in CO 2 emissions resulting from new energy conservation standards for commercial air conditioning equipment. 291 DOE derived the upper bound of this range from th e mean of published estimates of the SCC reported in the same earlier survey by Tol (2005) that NHTSA relied upon for the value it used to analyze the CAFE standards proposed in the NPRM, and the lo wer bound from the assumption that reducing CO 2 emissions would produce no economic benefit. Ho wever, NHTSA believes that the estimates of
the mean and standard deviation derived from Tol’s more recent (2008) and comprehensive survey of published estimates of the SCC provi des a more up-to-date range of values for
reductions in CO 2 emissions resulting from higher CAFE standards, primarily because Tol’s 2008 survey includes a larger number of estimat es of the SCC, as well as more recentlypublished estimates.

The agency is aware that rapi d advances in modeling climate change and its potential economic damages have occurred over the past decade, an d that the choice of discount rates has an

286 See Hope, Chris, and David Newbery, “Calculating the Social Cost of Carbon,” unpublished paper, Cambridge University, May 2006, p. 15.

287 U.S. EPA, Technical Support Document on Benefits of Reducing GHG Emissions, EPA-HQ-OAR-2008-318- 0078.pdf, June 12, 2008.

288 Equity weighting assigns higher weights per dollar of economic damage from climate change that are expected to be borne by lower-income regions of the globe, in an attempt to make the welfare changes corresponding to those damages more comparable to the damages expected to be sustained by higher-income world regions.

289 These values are reported in EPA, Table 1. p. 12. Using the original estimates included in Tol’s 2008 survey, which were supplied to NHTSA by the author, the agency calculates these values at $38 per ton and $62 per ton for 3% and 2% discount rates, slightly below the estimates repo rted by EPA. These differences may be attributable to the two agencies’ use of different measures of inflation to update the original estimates from mid-1990s to 2007 price levels (NHTSA employs the Implicit Price Deflator fo r U.S. GDP, generally considered to be an accurate index of economy-wide price inflation).

290 Tol (2008), Table A1.

291 Department of Energy, 10 CFR Part 431, Energy Conservation Program for Commercial and Industrial Equipment: Packaged Terminal Air Conditioner and P ackaged Terminal Heat Pump Energy Conservation Standards: Final Rule, Federal Register , October 7, 2008, pp. 58813-58814.VIII-49

important influence on estimates of the SCC. In its next CAFE rulemaking, NHTSA will be working closely with EPA and other federal agenci es to review the arguments for more selective use of published estimates of the SCC advocated by the EPA. However, based on the information gathered and analysis performed by th e agency through last fall, and in view of the fact that this is a one model year rulemaking a nd the agency will review matters in considerable detail for the post MY 2011 proposal to be issued later this year, NHTSA is not now taking that step. Thus, for the purposes of this final rule , NHTSA has elected to use all 125 SCC estimates from peer-reviewed studies reported by Tol, instead of the more limited subset of these estimates relied upon by EPA. Including the full array of st udies provides a reasonable basis for valuing
reductions in CO 2 emissions. Specifically, NHTSA believes th at there is still value at this time in considering pre-1995 studies and those that em ploy equity weighting (which account for 58 of the 125 peer-reviewed estimates in cluded in Tol’s survey), partic ularly recognizing that those studies have been published in peer-reviewed journals. 292

For the purpose of this rulemaking, NHTSA has also elected not to base its estimates of the value of reducing CO 2 emissions solely on estimates that utilize a single discount rate. NHTSA acknowledges that the varying discount rates em ployed by different resear chers are an important source of the significant differen ces in their resulting estimates of the SCC. However, the agency believes that the appropr iate rate at which to discount economic damages occurring in the distant future is an economic parameter whose co rrect value for the purpose of analyzing future climate change and the resulting economic damages is subject to significant uncertainty, analogous to that surrounding ot her critical scientific and eco nomic parameters in climate analysis. In the agency’s view , it is reasonable to consider es timates based on different discount rates at the present time instead of attempting to resolve this uncertainty in the time left to complete this one-year rulemaking by limiting the sa mple of estimates to those that employ the single discount rate it regards as most approp riate. In its next CAFE rulemaking, NHTSA will work with EPA, DOE and other federal agencies to consider anew the issue of whether to rely exclusively on values of the SCC that are develope d using discount rates that are consistent with the rate the agency uses to di scount the value of reductions in future GHG emissions reductions to their present values. 293

292 Again using the original estimates from Tol’s 2008 survey supplied by the author, NHTSA estimates that excluding the 18 pre-1995 estimates from the 125 used to develop the $33 per ton mean estimate would increase it to $36 per ton, while excluding the 40 estimates that employ equity weighting would reduce the mean estimate to $23 per ton. Excluding both pre-1995 estimates and those that employ equity weighting would eliminate a total of 58 of the 125 peer-reviewed estimates, and reduce their mean value to $20 per ton.

293 Climate economic studies report estimat es of the SCC for specific future year s, often in the form of a value for some stated base year and an estimate of the annual rate at which it will grow, as total atmospheric concentrations of
GHGs are assumed to increase. These studies use some assumed rate to discount economic damages that are projected to occur over a very long span of future years to their present va lues as of the future year when emissions
increases are assumed to occur. These estimates of the SCC during specific future years are used to value the
reductions in GHG emissions that would result each year over the lifetimes of ve hicles affected by CAFE standards; for example, higher CAFE standards for model year 2011 cars and light trucks would reduce GHG emissions each year from 2011 through approximately 2047, and the value of reducing thos e emissions by one ton will rise each year over that span. The estimated eco nomic values of the reductions in GHG emissions during each of those future years must in turn be discounted to their present values as of today, so that they can be compared with the present values of other benefits and with vehicle manufacturers’ costs for meeting higher CAFE standards. The rate used to perform this latter discounting must be selected by NHTSA, and the choice of its valu e is discussed in detail in
Section V.B.14VIII-50

As some commenters pointed out, another approach NHTSA could rely on to estimate the value of reducing GHG emissions would be to us e actual or projected prices for CO 2 emission permits in nations that have adopted or proposed GHG emi ssion cap and trade systems. In theory, permit prices would reflect the incremental costs for achieving the last emissi ons reductions necessary to comply with the overall emissions cap. If this cap were based on an es timate of the level of global emissions required to prevent an unaccep table degree of climate change, permit prices could provide an estimate of the benefits of reducing GHG emissions to a level that forestalls unacceptable climate change. A related approach would be to use estimates of the cost of reducing emissions from specific sources other than passenger cars or light trucks to estimate the value of reducing CO 2 emissions via higher CAFE standard s, under the reasoni ng that requiring higher fuel economy for cars and lig ht trucks would allow these co sts to be avoided or saved.

NHTSA considered the use of CO 2 permit prices to measure the benefits from reducing emissions via higher CAFE standards, but did not select this approach primarily because of the current difficulty in deciding what is consider ed an “acceptable” degree of climate change. The answer to that question cannot be provided by environmental, tec hnological or economic analyses alone or even in combination; answeri ng that question also involves policy judgment. The agency also notes that there would also be co nsiderable scientific uncertainty in determining
the level of emissions reduction that would be necessary to limit climate change to any degree that was deemed acceptable, even if agreemen t on the latter could be achieved. Since permit prices would depend on the level of emission reduc tion that is required, they are likely to reflect this uncertainty. Additionally, as a general matter, permit prices reflect avoided costs of
emission reductions and there is no direct or necessary relatio nship between avoided costs and
benefits.

Finally, still other commenters urge d the agency to take into a ccount the economic value of any
reduction in the risk of catas trophic climate events resulting from lower GHG emissions when estimating the benefits from reducing emissions. Most of the estimates of the SCC that are included in Tol’s updated review treat the risks and potential da mages from catastrophic events using conventional probabilistic methods to com pute the “expected” value of a wide range of potential changes in climate and associated eco nomic damages. However, few studies of the SCC attempt to include explicit premiums that measure the population’ s aversion to accepting the risks of catastrophic climate damages. 294 Further, most published studies of climate damages report insufficiently detailed results to allow th e calculation of appropria te risk premiums.

294 Under the conventional assumption that successive increases in consumption produce progressively smaller improvements in economic welfare, the welfare level associated with the mean of a range of possible consumption levels is higher than the mean of the welfare levels associated with each possible level of consumption. Moreover, the difference between these welfare levels increases as the span of possible consumption levels is broadened, as would occur if increased GHG emissions have the potential to cause drastic climate changes and result in similarly drastic economic damages. In this situation, the true economic costs of increased em issions include not only the resulting increase in the probabilistic expected value of climate-related economic damages, but also the compensation that those suffering these damages would requ ire in order to willingly accept the increased risk of catastrophic damages, even if that risk is extremely small. Conversely, the value of reducing GHG emissions should include not only the resulting reduction in the expected valu e of future climate-related economic damages, but also the added amount people would be willing to pay for the a ssociated reduction in the risk that such catastrophic damage might occur.VIII-51

NHTSA acknowledges that including an appropriate premium to reflect the value of reducing the risks of catastrophic climate events could signif icantly increase its es timate of the value of reducing CO 2 emissions, but it has not attempted to do so at this time. 295 (For discussion of NHTSA’s consideration of abrupt climate cha nge, see § 3.4.3.2.4 of the FEIS.) However, the agency is aware of recent rese arch suggesting that including an appropriate risk premium can significantly increase estimates of the SCC, and by implication increase the estimated value of reducing CO 2 emissions. 296 In working with EPA, DOE and other federal agencies in the development of revised estimates of the benefits from reducing CO 2 emissions that could be used in the next CAFE rulemaking, NHT SA will carefully consider any new research that explicitly estimates risk premiums, and evaluate their app licability to the issue of estimating economic
benefits from reductions in CO 2 emissions resulting from future CAFE standards. The agency will also work with those agencies and departments in exploring the possibility of calculating an appropriate risk premium using results reported in published studies of the SCC together with any necessary assumptions about the underlying ec onomic behavior, such as the response of welfare to successive increases in consumption levels.

Domestic value of reducing CO 2 emissions The agency was able to develop a domestic valu e by using the mean estimate of the global value of reduced economic damages from clim ate change resulting from reducing CO 2 emissions as a starting point; estimating the fraction of the reduc tion in global damages that is likely to be experienced within the U.S.; and applying this fra ction to the mean estimate of global benefits from reducing emissions to obtain an estimate of the U.S. domestic benefits from lower GHG
emissions.

The agency constructed an estimate of th e U.S. domestic benefits from reducing CO 2 emissions using estimates of U.S. domestic and global be nefits from reducing greenhouse gas emissions developed by EPA and reported in that agency ’s Technical Support Docu ment accompanying its advance notice of proposed rulemaking on motor vehicle CO 2 emissions. 297 Specifically,
NHTSA calculated the ratio of domestic to global values of reducing CO 2 emissions estimated by EPA using the Climate Framework for Uncer tainty, Negotiation, a nd Distribution (FUND) integrated assessment model.

EPA’s central estimates of domestic and gl obal values for reducing GHG emissions during 2007 using the FUND model using a 3 percent discou nt rate were $1 and $17 per metric ton (in 2006$), which suggests that benefits to the U.S. from reducing CO 2 emissions are likely to represent about 6 percent of their global total. The comparab le figures derived using a 2 percent discount rate are $4 and $88 for 2007, suggesting that U.S. domestic benefits from reductions in

CO 2 emissions would amount to less than 5 percent of their global total. EPA’s results also suggest that these fractions are likely to remain roughly constant over future decades. 298

295 Tol estimates that including an appr opriate risk premium would increase th e mean estimate of the SCC included in his more recent survey by 15-27%; see Tol (2008), Table 2.

296 Hope, Chris, and David Newbery (2006), Calculating the social cost of carbon, University of Cambridge, May 2,

2006.

297 U.S. EPA, Technical Support Document on Benefits of Reducing GHG Emissions, June 12, 2008.

298 These values are reported in EPA, Table 1. p. 12.VIII-52

Applying the 5-6 percent figure to the $33 per metric ton mean estimate of the global value of reducing CO 2 emissions derived previously yields an estimate of approximately $2 per metric ton for the domestic benefit from reducing U.S. CO 2 emissions in 2007.

NHTSA also constructed a second estimate of th e fraction of global economic damages from climate change likely to be borne by the U.S., us ing the procedure described by Delucchi in his
comments on the NPRM. 299 Delucchi noted that the fraction of global damages from climate change borne within the U.S. can be estimated by adjusting the U.S. share of world economic output, measured by the ratio of U.S. GDP to gro ss world product, by the relative sensitivity of U.S. and world economic output to damages resu lting from climate change. Using data on the U.S. share of world economic output (which rang es from 20-28 percent) and published estimates
of the relative sensitiv ity of the U.S. economy to climate damages compared to the world economy as a whole, Delucchi estimated that the U.S. fraction of global economic damages from climate change is likely to range from 0-14 pe rcent. Applying the midpoint of this range (7 percent) to the $33 per ton mean estima te of the global value of reducing CO 2 emissions also yields an estimate of approximately $2 per me tric ton for the domestic benefit from reducing

U.S. CO 2 emissions in 2007.

Choosing between a global value and a domestic value, and estimating the global values As the IPCC has noted, CO 2 and other GHGs are chemically stable, and thus remain in the atmosphere for periods of a decade to centuries or even longer, becoming well-mixed throughout the earth’s atmosphere. As a consequence, emi ssions of these gases have extremely long-term effects on the global climate. Further, emissi ons from any particular geographic area (for example, the U.S.), are expected to contribute to changes in the global climate that will affect many other countries around the world. Similarly, emissions occurring in other countries will contribute to changes in the earth’s future climate that are expected to affect the well-being of the U.S. The long-lived nature of atmospheric GHGs means that emissions of these gases from any
location or source can affect the global climate over a prolonged period, and can thus result in economic damages to many other nations as well as over subsequent generations.

In view of the global effects of GHG emissions , reducing those emissions to an economically efficient level, i.e. , one that maximizes the difference between the total benefits from limiting the extent of climate change and the total costs of achieving the reduction in emissions necessary to do so, would require each individual nation to limit its own domestic emissions to the point
where its domestic costs for further reducing emissi ons within its borders equal the global value of reduced economic damages that result from limiting climate change. NHTSA believes that this argument has considerable merit from the standpoint of economic theory.

If individual nations were instead to consider only the domestic benefits they receive from limiting the pace or extent of climate change, each nation would reduce emissions only to the point where its costs for achievi ng further reductions equal the be nefits to its domestic economy from limiting the impacts of climate change. As a result, the combined global reduction in

299 Mark A. Delucchi, Summary of the Non-Monetary Ex ternalities of Motor Vehicle Use, UCD-ITS-RR-96-3 (9) rev.1, Institute of Transpor tation Studies, University of California, Da vis, originally published September 1998, revised October 2004, pp. 49-51. Available at http ://www.its.ucdavis.edu/publications/2004/UCD-ITS-RR-96- 03(09)_rev1.pdf (last accessed March 23, 2009).VIII-53

emissions resulting from individual nations’ comparisons of their domestic benefits from limiting climate change to their domestic costs for reducing emissions might be inadequate to slow or limit climate change.

At the same time, however, the agency must also consider the economic, environmental and other effects on the U.S. that a choice of a globa l value in this rulemaking might have, given the current stage of ongoing domestic legislative activity and nego tiations regarding effective international cooperation and coordination. NHTSA notes that there might be risks to nations that unilaterally attempt to reduce their emi ssions by adopting policies or regulations whose domestic marginal costs equal the global marginal benefits from reducing the threat of climate change. Such actions could induce economic ac tivity within their bor ders – particularly production by emissions-intensive industries – to shift to nations that adopt less stringent regulations or lower economic penalties on emi ssions within their resp ective borders. Such a shift would cause emissions abroad to increase, offsetting at least some of the benefits of
domestic emissions reductions.

The agency recognizes that the arguments for us ing global versus domestic values of reducing GHG emissions are complex, and cannot be resolved satisfactorily by the unilateral actions of any single federal agency. Inst ead, resolution of whether to us e a domestic or global value for reducing emissions, and developing reliable estimates of those values, as relevant, will require active participation by all federa l agencies whose regulatory and policy-making activities will be affected by this decision, as well as leadership from the Administration. In reaching such a consensus, participants will need to assess no t only the economic arguments favoring global versus domestic values of reducing emissions, but also the prospects for effective international cooperation to reduce global GHG emissions, the likelihood that leadersh ip by the U.S. in seeking emissions reductions would spur intern ational efforts to reduce emissions, and the precedents established by federal agencies that have previously evaluated benefits from regulations that lower GHG emissions. They will also need to consider arguments that U.S. citizens may attach some value to reductions in the threat of climate im pacts occurring in other regions of the globe, and that re ducing the impacts of climate change on other nations may have important “spillover” benefits to the U.S. itself. A position has not been adopted by the relevant
entities.

In these circumstances, NHTSA decided to take a pragmatic approach to estimating the value of reducing GHG emissions for the immediate and lim ited purpose of this rulemaking. As noted above, we used the mean value in Tol (2008). To develop a reasonable upper-bound estimate of that value for purposes of this rule, the agency used a value one standard deviation above the $33
mean value. 300 As also noted above, the standard de viation of peer-reviewed estimates from Tol’s 2008 survey is $47 per ton when expressed in comparable terms, which yields an upperbound estimate of $80 per ton (equal to $33 plus $47) of CO 2 emissions avoided. 301 Because the

300 A two-standard deviation range around the agency’s $33 per ton central estimate would extend from minus $59 to $126 per ton of CO 2 emissions. The agency notes that the lower end of this range implies economic benefits of $59 for each additional ton of CO 2 emissions during 2007, while its upper end significantly exceeds all but two of the 125 peer-reviewed estimates included in Tol’s 2008 survey.

301 A value one standard deviation below the $33 mean woul d be -$14 per ton, which implies economic benefits of $14 for each additional ton of emissions. Because of this implication, NHTSA re gards the $2 per ton estimate of theVIII-54

$80 per ton value is higher than those corres ponding to nearly 90% of the 125 peer-reviewed estimates of the SCC included in the survey, the agency views it as a reasonable upper bound on the likely global value of reducing CO 2 emissions. 302 For the purposes of this rulemaking, NHTSA believes that the range extending from th e $2 per ton estimate of the domestic value of reducing CO 2 emissions to the $80 per ton estimate of the global value is sufficiently broad to illustrate the sensitivity of alternative MY 2011 CAFE standards and the resulting fuel savings and emissions reductions to plausible differences in the SCC.

Rate of growth of SCC The marginal cost per ton of additional CO 2 emissions is generally expected to rise over time, because the increased pace and degree of clim ate change – and thus the resulting economic damages – caused by additional emissions are both expected to rise in proportion to the existing
concentration of CO 2 in the earth’s atmosphere. The IP CC Fourth Assessment Report variously reported that the climate-related economic dama ges resulting from an additional ton of carbon emissions are likely to grow at a rate of 2.4 percent annually, and at a rate of 2-4 percent annually. 303 Virtually all commenters who addressed this issue indi cated that the IPCC intended the 2.4 percent growth rate it reported for the S CC in one passage to instead read “2-4 percent,” and many urged NHTSA to apply a 3 percent or highe r growth rate to determine the future value
of the SCC.

NHTSA staff reviewed the underlying references from which the disput ed figure was derived, and those sources clearly report th e growth rate implied by their estim ates of the future value of the SCC for different future years as 2.4 percen t, instead of the 2-4 percent asserted by

commenters. 304 Although most studies that estimate economic damages caused by increased GHG emissions in future years produce an implied gr owth rate in the SCC, neither the rate itself nor the information necessary to derive its implied value is commonly reported. NHTSA has been unable to locate other published research that reports the likely future rate of growth in damage costs from CO 2 emissions or the information require d to derive it. NHTSA understands that other researchers may be using alternative growth rates. The agency may revise the estimated rate of growth it uses in its future analyses based on emerging estimates in the literature and on interagency coordination with the EPA, DOE and other federal agencies.

For the purposes of this rulemaking, NHTSA used the 2.4 percent annual grow th rate to calculate
the future increases in its estimates of both the domestic ($2/metric ton in 2007) and global ($33/metric ton and $80/metric t on in 2007) values of reducing CO 2 emissions. Over the lifetimes of cars and light trucks subject to the CAFE standards it is establishing for model year 2011, these values average nearly $4, $61, and $157 per ton of CO 2 emissions, approximately

domestic value of reducing emissions as a more plausible lower bound on the value of reducing emissions than the $-14 per ton figure.

302 Tol reports that the 90% confidence limit of the distri bution of peer-reviewed values is $170 per ton, while adding one standard deviation to his reported mean yields a value of $169; see Tol (2008), Table 1.

303 Yohe et al. (2007), p. 13 reports that “...it is very likely that the rate of increase [in the social cost of carbon] will be 2% to 4% per year.” However, p. 822 states that “... the SCC will increase over time ; current knowledge suggests a 2.4% per year rate of growth.”

304 Hope, C.W. (2006), The Marginal Impact of CO2 from PAGE2002: An Integrated Assessment Model Incorporating the IPCC's Five Reasons for Concern, Integrated Assessment Journal , 6, (1), 19-56; and Hope, Chris, and David Newbery (2006), Calculating the social cost of carbon, University of Cambridge, May 2, 2006.VIII-55

twice their estimated values during 2007. The agency is unaware of the basis for EDF’s assertion that the 2.4 percent gr owth rate is to be used only in conjunction with an intergenerational discoun t rate with a maximum of 3 percen t. Although the agency’s analysis did follow EDF’s suggestion in any case, NHTSA selected the growth rate in the future value of reducing CO 2 emissions and the discount rate applied to these benefits for separate reasons, as discussed in detail previously.

Insensitivity of MY 2011 standards to different values of SCC NHTSA examined the sensitivity of alternative CAFE standa rds for MY 2011 to the choice among three different estimates of the value of reducing CO 2 emissions from fuel production and use: (1) the mean estimate of the global valu e of reducing emissions derived as discussed previously from Tol’s 2008 survey--$33 per ton; (2 ) a value one standard deviation above this mean estimate--$80 per ton; and (3) the estimate of the value of U.S. domestic benefits from
lower emissions derived as discussed above--$2 per ton. 305

The agency tested the sensitivity of its “optim ized” CAFE standards for MY 2011 passenger cars and light trucks to the choice among those three alternative va lues for reducing CO 2 emissions. The agency’s analysis revealed that the optim ized CAFE standards for MY 2011 cars and light trucks were unaffected by the choi ce among those values for reducing CO 2 emissions from fuel production and use. The detailed results of this analysis are reported in the agency’s previouslyreleased Final Environmental Impact Stat ement for MY 2011-15 CAFE standards.

There are several reasons for the insensitivity of the MY 2011 standards to the different values of the SCC. First, not more than 15 percent of all models are being redesigned for MY 2011, thus limiting the changes that can be made. Second, in any year, the value of gasoline has a far greater effect on the pote ntial level of the CAFE standards than the SCC. Third, in the analyses that employ the $33 or $80 per ton global va lues of the benefits from reducing CO 2 emissions, NHTSA reduces the savings in monopsony costs from lower U.S. petroleum consumption and imports to zero. 306 This is done in order to be consiste nt with the fact that monopsony payments
are a transfer rather than a real economic benefit when viewed from the same global perspective. This reduction partly offsets the effect of the higher CO 2 value on the optimized CAFE standards and resulting benefits. It does not do so completely, however, because the value of reducing CO 2 emissions continues to grow at the assumed 2.4 percent rate over the period spanned by the analysis, nearly doubling over the lifetimes of MY 2011 vehicles.

Decision regarding the value of SCC Given the insensitivity of the pot ential standards to the various va lues of SCC used in the above analysis, NHTSA concludes that it is unnecessary fo r the agency to select a single estimate of the

305 In all analyses that employ its estimated va lue of the global benefits from reducing CO 2 emissions, NHTSA reduces the value of the savings in monopsony costs from lower U.S. petroleum consumption and imports to zero.
This is consistent with the fact that when viewed from th e same global perspective that justifies the use of a global value for reducing emissions, these monopsony payments represent a transfer of economic resources from consumers of petroleum products to petroleum producers, rather than an actual savings in economic resources, and
thus do not constitute a real economic benefit.

306 As noted above earlier in the disc ussion of SCC, NHTSA plans to revi ew this practice in the next CAFE rulemaking.VIII-56

value of reducing CO 2 emissions for inclusion in its analysis as part of this rulemaking. For that reason and in view of the signi ficance that announcing the sel ection of either a domestic or global value in this rulemaking might have in the context of ongoing legi slative activities and international negotiations, we are deferring th e choice between a domes tic SCC and a global SCC and, for the appropriate choice, the moneti zed value for the benefit of reduction, until the next CAFE rulemaking. This will provide the time necessary for more refined analysis and for the various affected federal agencies to work t ogether and identify a consistent value for use in their respective regulatory and policy-making activities. NHTSA expects to participate actively in the process of developing an appropriate range of estimates for that value. By the time we issue a proposal this summer for MY 2012 and be yond, we anticipate those activities and efforts will have progressed sufficiently to enable the fe deral agencies to make an informed choice that we can use as a basis for that rulemaking. NHT SA expects that the ec onomic value of reducing

CO 2 emissions will play an importa nt role in developing and anal yzing standards in the next CAFE rulemaking which, unlike this rulemaking, we expect to be a five-year rulemaking.

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 o ccupants of the added (or more desirable) social and economic opportunities that become accessibl e 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 improve d level of fuel economy resulting from stricter CAFE standards). 307 The benefits from additional re bound effect travel also include the consumer surplus received by vehicle buyers wh o value the opportunities th at 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, an d is shown in Tables VIII-6 through VIII-10.

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 conge stion, motor vehicle crashes, and highway noise. A dditional vehicle use can contri bute to traffic congestion and delays by increasing recurring c ongestion on heavily-traveled ro adways during peak travel periods, depending on how the addi tional travel is distributed over the day and on where it occurs. By increasing the number of crashes a nd disabled vehicles, a dded driving can also increase the delays that often re sult from these incidents, although the extent to which it actually does so again depends on when and where the adde d travel occurs. In either case, any added delays impose higher costs on driv ers 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 driv ers 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 associ ated with the rebound effect.

307 These benefits are included in the value of fuel savings reported in Tables VIII-5 through VIII-9.VIII-57

Increased passenger car and light truck use due to the rebound effect may al so increase the costs associated with traffic crashes. Drivers presum ably take account of the potential costs they (and the other occupants of their vehicles) face from th e 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 thes e external crash costs caused by added driving is likely to depend on the traffic conditions un der which it takes place, since crashes are more frequent in h eavier 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 accoun t for when and where the added driving occurs.

Finally, added vehicle use from the rebound eff ect may also increase traffic noise. Noise generated by vehicles causes inconvenience, irritation, and potentially even discomfort to occupants of other vehicles, to pedestrians and ot her bystanders, and to re sidents or occupants of surrounding property. Because none of these effects are likely to be taken into account by the
drivers whose vehicles contribu te to traffic noise, they represent additional externalities associated with motor vehicle use. Although ther e is considerable uncerta inty in estimating its value, the added inconvenience a nd irritation caused by increased traffic noise imposes economic costs on those it affects, and thes e 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 co sts from the rebound effect.

Our analysis uses estimates of the congestion cost s, crash costs, and noise costs for pickup trucks and vans developed by the Federal Highway Admini stration to estimate the increased external costs caused by added light truck use from the rebound effect. 308 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 tr affic crashes, and noi se 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 vehicl e mile when expressed in 2006 dollars. 309 For pickup trucks and vans these costs are 4.66 cents, 2.51 ce nts, 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’ lifetim es in the fleet to yield the estimated increases in congestion, crash, and noise externality costs durin g that year. The resulting estimates are discounted to their present values as of th e 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 increase d light-duty vehicle use

308 These estimates were developed by FHWA for use in its 1997 Federal Highway Cost Allocation Study

.

309 Federal Highway Administration, 1997 Federal Highway Cost Allocation Study , Tables V-22, V-23, and V-24, http://www.fhwa.dot.gov/polic y/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.VIII-58

in the U.S. to be 3.9 and 3.4 cents per vehi cle-mile when converted to 2006 dollars. 310 These estimates incorporate careful adjustments of co ngestion 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 se verity of motor ve hicle crashes.

Costs from Increased Air Pollutant Emissions Finally, as noted previously under Emissions Reduc tions 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 dr iven. Predominant air pollutants emitted by motor vehicles include hydrocarbon compounds (usually referred to as “volat ile organic compounds,” or VOC), nitrogen oxides (NOx), fine partic ulate matter (PM), and sulfur dioxide (SO 2 ). The increased use of passenger cars and light trucks that occurs through th e 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 ca lendar year by age-specific emission rates per vehicle-mile developed using the U.S. Envir onmental Protection Agency’s MOBILE6.2 motor
vehicle emissions factor model 311 . The monetized value of ch anges in criteria pollutant emissions (fine PM, NOx, SO2, VOCs andCO) are derived from EPA estimates of the value of health and welfare-related 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 source s, a category that includes passenger cars, light trucks, and other highway vehicles. 312

The Value of Increased Driving Range Improving the fuel economy of passenger cars and light-duty trucks ma y 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 im proved fuel economy by reducing
the size of fuel tanks to maintain a constant driving range, the resulting cost saving will presumably be reflected in lo wer vehicle sales prices.)

No direct estimates of the value of extended vehi cle range are readily available, so the agency’s analysis calculates the reduction in the annual numb er of required refueli ng cycles that results from improved fuel economy, and applies DOT-reco mmended values of travel time savings to convert the resulting time sa vings to their economic value. 313 As an illustration of how the value

310 Ian W.H. Parry and Kenneth A. Sm all, “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

.

311 U.S. Environmental Protection Agency, MOBILE6 Vehicle Emission Modeling Software, http://www.epa.gov/otaq/m6.htm#m60

312 EPA, “Mobile Source $ per Ton Estimates,” document provided to NHTSA by EPA Office of Transportation and Air Quality staff, June 26, 2007.

313 See http://ostpxweb.dot.gov/policy/Data/VOT97guid.pdf and http://ostpxweb.dot.gov/policy/Data/VOTrevision1_2-11-03.pdfVIII-59

of extended refueling range is es timated, 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 driv ing range from 384 miles (= 16 gallons x 24 mpg) to 400 miles (= 16 gallons x 25 mpg). A ssuming that it is driven 12,000 miles/year, this
reduces the number of times it needs to be re fueled each year from 31.3 (= 12,000 miles per year / 384 miles per refueling) to 30.0 (= 12,000 miles per year / 400 m iles 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 drivi ng trips (1.6 persons), the DOT-reco mmended value of travel time per vehicle-hour is $24.00 (in 2006 dollars). 314 Assuming that locating a station and filling up requires ten minutes, the annual value of time save d as a result of less frequent refueling amounts to $5.20 (calculated as 10/60 x 1.3 x $24.00). This calculation is repeat ed for each future calendar year that light trucks of each model y ear affected by the alternative CAFE standards
considered in this rule would remain in service. Like fuel savings a nd other benefits, however,
the value of this benefit declines over a mode l year’s lifetime, becau se a smaller number of vehicles originally produced dur ing that model year remain in service each year, and those remaining in service are driven fewer miles.

Table VIII-5 summarizes the values used to calculate the impacts of each scenario.

314 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 va lued 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-60

Table VIII-5 Economic Values for Benefits Computations (2007$)

Fuel Prices (average reta il gasoline price per gallon, 2011-30) $3.33

Rebound Effect (VMT Elasticity) -0.15 Discount Rates Applied to Future Benefits
Reductions in CO 2 Emissions Other Benefits 3%
7% Payback Period (years) 5.0
"Gap" between Test and On-Road MPG 20% Value of Travel Time per Vehicle ($/hour) $24.64 Economic Costs of Oil Imports ($/gallon) "Monopsony" Component $0.266 Price Shock Component $0.116 Military Security Component - Total Economic Costs ($/gallon) $0.381
External Costs from Additional Automobile Use Due to "Rebound" Effect ($/vehicle-mile)

Congestion $0.054
Accidents $0.023
Noise $0.001
Total External Costs $0.078 External Costs from Additional Light Truck Use Due to "Rebound" Effect ($/vehicle-mile)

Congestion $0.048
Accidents $0.026
Noise $0.001
Total External Costs $0.075
Emission Damage Costs Carbon Monoxide ($/ton) $ - Volatile Organic Compounds ($/ton) $1,700 Nitrogen Oxides ($/ton) $4,000 Particulate Matter ($/ton) $168,000 Sulfur Dioxide ($/ton) $16,000 Carbon Dioxide ($/metric ton) $ 2.00 Carbon Dioxide ($/metric ton) (U.S. domestic value) (Mean global value from Tol (2008) (One standard deviation above mean global value $2.00 $33.00 $80.00 Annual Increase in CO2 Damage Cost 2.4%VIII-61

Summary of Benefits

Benefits were calculated separately for passenge r cars and light trucks under each alternative CAFE requirement for each model year covered by th is proposal. In Tables VIII-6 through VIII7, the societal impacts for passenger car and light truck CAFE standards under the proposed Optimized Net Benefits altern ative is shown for model year 2011. These tables include undiscounted values as well as pres ent value calculations at 7 percen t. They also show changes in the physical units of measure that produced these values. Ne gative values in these tables
reflect net reductions in fuel consumption or emissions and th eir resulting economic impacts, which represent benefits from the proposal, whil e positive values repres ent increasing emissions, congestion, noise or crash severity and their added costs. The net social benefit from these societal impacts is shown on the To tal line in each table.

The proposed standards for passenger cars would sa ve approximately 463 million gallons of fuel and prevent 4 million metric tons of tailpipe CO 2 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 adju sted 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 $1billion 315

over the lifetime of the MY 2011fleet. This estimate of societ al benefits includes direct impacts from lower fuel consumption as well as externalities, and also reflects offsetting societal costs resulting from the rebound effect. Direct bene fits to consumers, including fuel savings, consumer surplus from additional driving, and reduced refueling time, account for 87.7 percent of the gross consumer benefits 316 resulting from increased pa ssenger car CAFE. Petroleum market externalities account for 10 percent. Envi ronmental externalities, i.e., reduction of air pollutants accounts for 2.3 percent.

The proposed standards for light trucks would save approximately 424 million gallons of fuel and prevent 4 million metric tons of tailpipe CO 2 emissions over the lifetime of the light trucks 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 th e proposed light truck st andards would be $920
million 317 . This estimate of societal benefits includes direct impacts from lower fuel consumption as well as externalities, and also re flects offsetting societal costs resulting from the rebound effect. Direct benefits to consumers, including fuel savings, consumer surplus from additional driving, and reduced refueling time, account for 87.6 percent of the gross consumer

315 The $1 billion estimate is based on a 7% discount rate for valuing future impacts. Undiscounted, these benefits are valued at almost $1.6 billion.

316 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, petroleum market externalities, reduced criteria pollutants, and reduced gr eenhouse gas production. Negative impacts from the rebound effect include added congestion, noise, and crash costs due to additional driving.

317 The $920 million estimate is based on a 7% discount rate for valuing future impacts. Undiscounted, these benefits are valued at about $1.5 billionVIII-62

benefits resulting from increased light truck CA FE. Petroleum market externalities account for 10 percent. Environmental externalities, i.e ., reduction of air pollutants accounts for 2.4 percent.

Table VIII-8 summarizes the fuel savings from all alternatives for passenger cars and light trucks. As would be expected, benefit levels parallel the increasing st ringency of the various
alternatives that were examine d. 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 valu e on benefits experienced in the future. The TC=TB scenario produces benefits that exceed the Optimized scenarios because it allows
benefits that accrue from cost-beneficial tec hnologies to offset costs that accrue from technologies that are not cost-ben eficial. As might be expecte d, the High Technology scenario,
which assumes the maximum use of all available t echnologies in all vehicles regardless of cost, produces higher savings than any of the 6 othe r scenarios. The 25% Below Optimized, 25% Above Optimized, and 50% Above Optimized s cenarios were designed to produce results relative to the Optimized scenario, and their benefits accordingly reflect this.

Tables VIII-9 summarizes the total social benefi ts from all alternatives for passenger cars and light trucks. These tables summari ze the value of net consumer be nefits over the lifetime of the
vehicles manufactured. The value of societal be nefits mirrors the trends in stringency across
alternative scenarios.VIII-63

Table VIII-6

Lifetime Monetized Societal Impacts, Optimized 7%, MY 2011, Passenger Cars

Societal Effect Physical Units Undiscounted Value (2007$ millions) Present Discounted Value @ 7%

Lifetime Fuel Expenditures -462,739(kgal) 1,296 842 Consumer Surplus from Additional Driving 1,827,193(kmiles) 158 103 Refueling Time Value 2,291,110(hours) 56 38

Petroleum Market Externalities -462,739(kgal) 168 112 Congestion Costs 1,827,193(kmiles) -98 -65 Noise Costs 1,827,193(kmiles) -1 -1 Crash Costs 1,827,193(kmiles) -42 -28 CO2 -4(mmT) 14 8 CO -44,493(tons) 0 0 VOC -2,171(tons) 4 2 NOX -1,547(tons) 6 4 PM -56(tons) 9 6 SOX -616(tons) 10 7 Total 1,580 1,027VIII-64

Table VIII-7

Lifetime Monetized Societal Impacts, Optimized 7%, MY 2011, Light Trucks

Societal Effect Physical Units Undiscounted Value (2007$ millions) Present Discounted Value @ 7%

Lifetime Fuel Expenditures -424,238(kgal) 1,206 747 Consumer Surplus from Additional Driving 1,370,561(kmiles) 147 92 Refueling Time Value 1,613,123(hours) 40 25

Petroleum Market Externalities -424,238(kgal) 154 98 Congestion Costs 1,370,561(kmiles) -66 -42 Noise Costs 1,370,561(kmiles) -1 -1 Crash Costs 1,370,561(kmiles) -35 -22 CO2 -4(mmT) 15 8 CO 5,409(tons) 0 0 VOC -1,047(tons) 2 1 NOX -737(tons) 3 2 PM -69(tons) 12 7 SOX -554(tons) 9 6 Total 1,484 921VIII-65

Table VIII-8 Savings in Millions of Gallons of Fuel Undiscounted, over the Lifetime of the Model Year 2011 Fleet

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 352 424 776 Optimized (7%) 463 424 887 25% Above Optimized (7%) 598 456 1,054 50% Above Optimized (7%) 794 456 1,250 Optimized (3%) 946 424 1,371 TC = TB (7%) 1,121 567 1,687 Technology Exhaustion (7%) 2,982 1,420 4,402

Table VIII-9
Present Value of Lifetime Social Benefits (Millions of 2007 Dollars)

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 786 921 1,707 Optimized (7%) 1,027 921 1,948 25% Above Optimized (7%) 1,332 989 2,321 50% Above Optimized (7%) 1,773 989 2,763 Optimized (3%) 2,647 1,176 3,824 TC = TB (7%) 2,487 1,189 3,676 Technology Exhaustion (7%) 6,406 2,950 9,356VIII-66

References

Argonne National Laboratories, The Greenhous e 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 Depend ence, ORNL-6873, Oak Ridge Nati onal Laboratory, May 11, 1995.

Greene, David L., James R. Kahn, and Robert C. Gibson, “Fuel Economy Rebound Effect for Household Vehicles,” The Ener gy 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. Passe nger 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 Nati onal Laboratory, November 1,

1997.

Pickrell, Don H., “Description of VMT Forecas ting Procedure for ‘Car Talk’ Base Line Forecasts,” manuscript, Volpe National Transpor tation Systems Center, U.S. Department of Transportation, 1994.

Puller, S.L., and L.A. Greening, “Household Ad justment 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 St udy to Evaluate the Effect of Reduced Greenhouse Gas Emissions on Vehicle Miles Traveled”, Stat e of California Air Res ources Board, California Environmental Protection Agency, and the California Energy Commission.

U.S. Department of Energy, Program Anal ysis Methodology Office of Transportation Technology: Quality Metrics 2002, Final Report, Office of Transportation Technologies, May 9,

2001.VIII-67

U.S. Environmental Protection Agency, MOBI LE 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 with the potential benefits, expressed in total costs (millions of dollars) from a societal perspective 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. These are incremental costs and be nefits compared to the adjusted baseline of manufacturers’ plans. Sensitivity analyses are also performed on some of the assumptions made in this analysis. Finally, a payback period is ca lculated, from the consumer’s perspective.

Table IX-1 provides the total incremental costs (in millions of dollars) from a societal perspective. Table IX-2 provides the total benefits from a societal perspective for all vehicles produced. Table IX-3 shows the total net benefits in millions of dollars for the projected fleet of sales for model year 2011.

Total costs follow a predictable pattern with costs rising to reflect the more expensive technologies that manufacturers must apply in orde r to achieve the CAFE levels that are required under the more aggressive altern atives, with th e exception of the Optimi zed (3%) alternative for light trucks. For the combined fleet, total comp liance costs for the Total Cost = Total Benefit alternative is roughly 3.5 times those for the Op timized (7%) alternativ e. Relative to the proposed Optimized (7%) alternative, Technology Exhaustion produces cost s that are 15.8 times the Optimized cost levels.

From Table IX-2, lifetime societ al benefits follow a similar pr edictable pattern, with higher benefits associated with the more expensiv e technologies that are enabled under the more aggressive alternatives. For the combined fleet , the TC=TB alternative produces gross benefits roughly 1.9 times as high as the Optimized (7 %) alternative, and th e Technology Exhaustion alternative produces gross bene fits that are 4.8 times the Op timized (7%) alternative.

While the pattern for benefits is directionally similar to the pattern for costs, the more aggressive technology scenarios do not increas e benefits by as high a ratio as they do for costs. For example, the TC=TB alternative increases total bene fits, but it also increases total costs, resulting in a net loss to society of $334 million. 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 th e marginal benefit, the TC=TB scenario and the Technology exhaustion scenario al low for continued investmentin technology despite its negative net return. Thus, while both costs and bene fits continue to rise with more aggressive technologies, the costs rapidly begin to exceed th e benefits that society derives from the added
investment.

The impact of the relatively unr estricted technology a pplication that is enabled by the more aggressive scenarios is apparent from Table IX-3, which shows net total lifetime societal benefits under each alternative. The Op timized (7%) or the Optimized (3%) alternative produces the highest net total benefits to society, as w ould be expected. The TC=TB and Technology
Exhaustion alternativ es produce a net loss to society.IX-2

Table IX-1 Incremental Total Cost – Societal Perspective (Millions of 2007 Dollars)

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 291 649 940 Optimized (7%) 496 649 1,145 25% Above Optimized (7%) 1,003 915 1,918 50% Above Optimized (7%) 1,630 915 2,545 Optimized (3%) 1,820 649 2,469 TC = TB (7%) 2,619 1,391 4,009 Technology Exhaustion (7%) 11,907 6,214 18,120

Table IX-2
Present Value of Lifetime Soci etal Benefits by Alternative (Millions of 2007 Dollars)

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 786 921 1,707 Optimized (7%) 1,027 921 1,948 25% Above Optimized (7%) 1,332 989 2,321 50% Above Optimized (7%) 1,773 989 2,763 Optimized (3%) 2,647 1,176 3,824 TC = TB (7%) 2,487 1,189 3,676 Technology Exhaustion (7%) 6,406 2,950 9,356IX-3

Table IX-3
Net Total Benefits
Over the Vehicle’s Lifetime – Present Value (Millions of 2007 Dollars)

Passenger Cars Light Trucks Passenger Cars and Light Trucks

Combined 25% Below Optimized (7%) 496 272 767 Optimized (7%) 531 272 802 25% Above Optimized (7%) 329 75 403 50% Above Optimized (7%) 143 75 218 Optimized (3%) 828 527 1,355 TC = TB (7%) (132) (202) (334) Technology Exhaustion (7%) (5,501) (3,264) (8,765)

Sensitivity Analyses The agency has performed several sensitivity anal yses to examine important assumptions. The analyses include:

1) The value of CO 2 . We examined $2 per metric ton as a domestic value, $33 per metric ton as a global value and $80 per metric ton as a global value. These values can be translated into cents per gallon by multiplying by 0.0089 318 , as shown below:

$2 per ton CO 2 = $2*0.0089 = $0.0178 per gallon $33.00 per ton CO 2 = $33*0.0089 = $0.2937 per gallon $80.00 per ton CO 2 = $80*0.0089 = $0.712 per gallon

2) The value of monopsony costs. For domestic values of CO 2, the main analysis uses $0.27 per gallon for monopsony costs. At the low end of the range for domestic values, the sensitivity analysis examines $0.21. For global values of CO 2, a $0 value of monopsony cost is appropriate.

3) The price of gasoline. The main analysis uses the AEO 2008 high cost case estimate for the price of gasoline (see Table VIII-3). In th is sensitivity analysis we also examine the reference case estimate of the price of gasoline from AEO 2008 estimate.

318 The molecular weight of Carbon (C) is 12, the molecular we ight of Oxygen (O) is 16, t hus the molecular weight of
CO 2 is 44. One ton of C = 44/12 tons CO 2 = 3.67 tons CO 2 . 1 gallon of gas weighs 2,81 9 grams, of that 2,433 grams are carbon. $1.00 CO 2 = $3.67 C and $3.67/ton * ton/1000kg * kg/1000g * 2433g/gallon = (3.67 * 2433) / 1000 * 1000 = $0.0089/gallonIX-4

4) Military security. For one of the scenario s, we added a $0.05 per gallon military security

cost.

Sensitivity analyses were performed on just the optimized (7%) alternative. Presented are information on the average mpg expected to be achieved by the manufact urers, the price per vehicle increase, total benefits, the total cost in crease, the total lifetime fuel saved and the total

CO 2 emissions reduction.

Table IX-4 Sensitivity Analyses

Fuel Prices CO2 Value Monopsony Military Security Final Rule High $2 $0.27 0

Low Global
Carbon High $33 0 0

High Global
Carbon High $80 0 0

Low Fuel Low $2 $0.21 0

Low Fuel High Military Low $2 $0.21 $.05

In the PRIA, we examined the sensitivity of the pr ice of gasoline (low, re ference, and high case), values of CO2 ($0 to $14 per ton), combined externalities ($0.120 and $0.504 per gallon), and the rebound effect (10 to 20 percent). Only the pr ice of gasoline had a significant impact on the results. We repeated the rebound effect sensitiv ity analysis for the Fina l Environmental Impact Statement (FEIS). The results of these sensitiv ity analyses are shown in the FEIS at Section 3.4.4.2. Reducing the rebound effect from the 15 percen t to 10 percent would have only a slight effect on fuel savings and reductions in CO 2 emissions. In contrast, increasing the rebound effect from the 15 percent value to 20 percent would lower the combined passenger car and light truck fuel savings by 0.5 to 1.5 mpg for the scenar ios examined in Tables 3.4-3 and 3.4-4 of the

FEIS.

The results of the sensitivity analyses i ndicate that the much wider values of CO 2 examined have almost no impact on the achieved mpg levels fo r passenger cars and a small impact on the light truck levels. The low fuel pri ce has an impact on the light truck levels of 0.3 mpg. The high military cost (only $0.05 per gallon) has no impact on the level of the standards.

Note that there are some slight inconsistencie s in the relationships one would expect when comparing the required mpg levels for corres ponding model years in the various sensitivity analyses to those under the final rule CAFE standa rds. For example, the level of the standard
should increase when CO 2 is assigned a higher value, because this increases the benefit of each gallon of fuel saved, but the op timized standards are actually lower with the high CO 2 value than
under the final rule. Problems such as this aris e when making slight changes in parameter valuesIX-5

used by the CAFE model, since the model derives a relationship between net benefits and the stringency level of standards, and minor changes in parameter values can affect the exact shapes and positions of those curves. In any case, th e seemingly anomalous results are mostly small (0.1 mpg or less). When larger variations are ma de to the model’s parameters or other inputs, such as substituting the Reference Case gasoline pr ice forecast, the sensitivity analysis invariable produces the anticipated result.IX-6

Table IX-5 Passenger Car Sensitivity Analyses (mpg)

MY 2011
Final Rule 30.7

Low Global Carbon 30.7 High Global Carbon 30.7

Low Fuel 30.7 Low Fuel, High Military 30.7

MY 2011
Per Vehicle

Cost

($) MY 2011
Total Benefits ($Mill.) MY 2011
Total Cost

$(Mill.) Total Fuel
Saved (Bill. Gal.) Total CO 2 Emissions

(mmt)

Final Rule 64 1,027 496 463 4.3

Low Global
Carbon 48 935 354 392 3.6

High Global
Carbon 48 1,121 354 392 3.6

Low Fuel 45 662 317 404 3.7

Low Fuel High Military 45 662 317 404 3.7IX-7

Table IX-6 Light Truck Sensitivity Analyses (mpg)

MY 2011
Final Rule 23.2

Low Global Carbon 23.1 High Global Carbon 23.1

Low Fuel 22.9 Low Fuel, High Military 22.9

MY 2011
Per Vehicle

Cost

($) MY 2011
Total Benefits ($Mill.) MY 2011
Total Cost

$(Mill.) Total Fuel
Saved (Bill. Gal.) Total CO 2 Emissions

(mmt)

Final Rule 126 921 649 424 3.9

Low Global
Carbon 121 944 613 408 3.8

High Global
Carbon 316 3,774 1,794 1,372 12.6

Low Fuel 95 297 560 220 2.0

Low Fuel High Military 95 297 560 220 2.0IX-8

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 doi ng 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 purchasi ng fuel to operate them. Over time, buyers may recoup the higher purchase prices they pay fo r 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 in itial 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 st andard, 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 so cietal 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 consumer s generally only consider and respond to what they pay at the pump. The payback periods are estimated as an average for all
manufacturers for the different alternatives. The payback periods for MY 2011 are shown in
Table IX-7.

Table IX-7 Payback Period for MY 2011 Average Vehicles (in years)

Passenger
Cars Light
Trucks

25% Below Optimized 3.7 7.7 Optimized (7%) 4.4 7.7

25% Above Optimized 5.2 10.0

50% Above Optimized 8.2 10.0 Optimized (3%) 7.7 7.7

TC = TB 9.2 Never Technology
Exhaustion Never NeverX-1



### X. PROBABILISTIC UNCERTAINTY ANALYSIS

OMB Circular A-4 requires formal probabilistic uncertainty analysis of complex rules where there are large, multiple uncertainties whose analys is raises technical challenges or where effects cascade and where the impacts of th e 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 probabili ty distribution of the benefits, costs, and net benefits of the compliance options selected for the proposed rule for MY 2011 passenge r car and light truck CAFE standards. Throughout the co urse 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 inevitab ly a level of uncertainty in these selections. Some of these inputs contributed le ss to the overall variations of the outcomes, and, thus, are less significant. Some input s depend on others or are closely re lated (e.g. oil import externalities),
and thus can be combined. With the vast numbe r 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 qua ntifies them by their probability distributions. These newly defined va lues are then randomly selected and fed back into the model to determine the net benefits using the Monte Carlo statistical simulation technique. 319 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 th e mathematical model represents an uncertainty factor that would potentially alter the mode ling outcomes if its value was changed. We assume that these variables are independent of each other. The confidence
intervals around the costs and bene fits of technologies reflect inde pendent levels of uncertainty regarding costs and benefits, ra ther than linked probabilities dependent on higher or lower quality versions of a specific technology. By c ontrast, there is reason to believe that monopsony costs may be dependent on fuel prices. Howeve r, 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 indepe ndence 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 de scribed by appropriate pr obability distribution
functions based on available data. If data are not sufficient or not av ailable, professional judgments are used to estimate the probability di stributions of these uncertainty factors. A complete description of the formulas and methods used in the CAFE mode l is available in the public docket. 320

319 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.

320 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 resu lts 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 s cenario. 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 th en 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 de gree of certainty provides the d ecision-maker with an additional piece of important information with wh ich to evaluate the forecast results.

A. Simulation Models and Uncertainty Factors A Monte Carlo simulation was conducted using th e CAFE modeling system that was developed to estimate the impacts of higher CAFE requireme nts described in previous chapters. The focus
of the simulation model was variation around th e chosen uncertainty parameters and their resulting impact on the key output parameters, fu el 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 th e 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 consum ption externalities; and (5) The rebound effect. (6) Greenhouse gas values



### Technology Costs
The costs incurred by manufacturers to modify th eir 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 different technologies we re 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 (midrange values) were used in the main analysis. For the uncertainty analysis, the full range of NAS cost estimates is used. The uncertainty model a ssumes a normal distribution for these costs, with each end of the range being three standard deviations from the mean (or expected) value. Since only 9 of the 40 technologies had range estimate s for costs, the range across the remaining 31 technologies was estimated based on the average range found in the 9 technologies with rangeX-3

estimates (+-29%) Figure X-1 graphically demo nstrates the distributions of a hypothetical sample of three of the technologies.

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 manuf acturers to enable their vehicl es 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 standard s, 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 th at manufacturers will c hoose to meet CAFE, the
CAFE model tests the interacti on of technology costs and effectiv eness 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 different t echnologies 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 estimate s is used. The uncertainties model assumes aX-4

normal distribution for these values, with each end of the range being three standard deviations from the mean (or expected) value. Since only 30 of the 40 technologies had range estimates for effectiveness, the range across the remaining 10 technologies was estimated based on the average range found in the 30 technologies with range estimates (+-31%)

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 de terminant 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). Fo r reasons discussed previously, the main analysis is based on the AEO High Case scenario, which represents the Agency’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 Reference Oil Price scenario (ROP). Both
scenarios were also derived from the AEO 2008. These 2 alternate scenarios were chosen to allow for the possibility that the EIA’s High Ca se predictions could ove restimate the price of gasoline in the future. Oil prices have been extremely volatile over the past year, climbing to record highs and then most recently dropping to levels consistent with a year ago.

Each of these scenarios was app lied 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 modele d using discrete weights of 60 percent for the High Case, and 35 percent for th e Reference Case and 5 percent for the LOP Case. Table X-1 lists the AEO gasoline price forecasts under each scenario. These same prices are demonstrated graphically (in 2007 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 (2007 dollars)

Year Low Reference High

2011 $2.397 $2.551 $2.949
2012 $2.263 $2.475 $2.974
2013 $2.141 $2.404 $3.023
2014 $2.032 $2.388 $3.077
2015 $1.906 $2.315 $3.093
2016 $1.791 $2.254 $3.138
2017 $1.791 $2.266 $3.200
2018 $1.791 $2.292 $3.241
2019 $1.815 $2.360 $3.301
2020 $1.890 $2.419 $3.363
2021 $1.866 $2.384 $3.451
2022 $1.883 $2.404 $3.491
2023 $1.879 $2.412 $3.492
2024 $1.862 $2.407 $3.510
2025 $1.858 $2.423 $3.485
2026 $1.851 $2.436 $3.494
2027 $1.853 $2.449 $3.518
2028 $1.858 $2.472 $3.545
2029 $1.877 $2.496 $3.576
2030 $1.892 $2.512 $3.618
2031 $1.892 $2.512 $3.618
2032 $1.892 $2.512 $3.618
2033 $1.892 $2.512 $3.618
2034 $1.892 $2.512 $3.618
2035 $1.892 $2.512 $3.618
2036 $1.892 $2.512 $3.618
2037 $1.892 $2.512 $3.618
2038 $1.892 $2.512 $3.618
2039 $1.892 $2.512 $3.618
2040 $1.892 $2.512 $3.618
2041 $1.892 $2.512 $3.618
2042 $1.892 $2.512 $3.618
2043 $1.892 $2.512 $3.618
2044 $1.892 $2.512 $3.618
2045 $1.892 $2.512 $3.618
2046 $1.892 $2.512 $3.618

2047 $1.892 $2.512 $3.618X-6

Figure X-2

AEO 2008 Retail Fuel Price Scenarios

$0.00 $0.50 $1.00 $1.50 $2.00 $2.50 $3.00 $3.50 $4.002011201420172020202320262029203220352038204120442047

YearRetail Price Low

Reference

High



### Oil Consumption Externalities

Reduced fuel consumption can benefit society by lowering the world market price for oil, reducing the threat of petrol eum supply disruptions, and reduc ing the cost of maintaining military security in oil producing regions and ope rating the strategic petroleum reserve. These benefits are called “externalities” because they ar e not reflected directly in the market price of fuel. A full description of thes e externalities is included in Chapter VIII under “Other Economic Benefits from Reducing Petroleum Use.” These f actors increase the net social benefits from reduced fuel consumption. Although they represen t a relatively small portion of overall social benefits, there is a signif icant level of uncer tainty 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 reduc ed 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 va lued in this analysis. A norma l distribution was assumed for the range of values for oil consumption externalities with the low and high valu es assumed to be two standard deviations from the mean, based on the Leiby estimates.X-7

Table X-2 Uncertainty Ranges for Oil Consumption Externalities ($/gallon)

Low Expected High For reducing U.S. demand on world market price $0.008 $0.266 $0.524

For reducing the threat of supply disruptions $0.034 $0.116 $0.198



### 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 m iles driven per vehicle. This “rebound effect” impacts net societ al benefits because the increas e in miles driven offsets a portion of the gasoline savings that results from more fuel-efficien t vehicles. Although
consumers derive some value from this extra driving, it also leads to increases in crash, congestion, noise, and pollution cost s associated with driving. Most recent estimates of the magnitude of the rebound effect for light duty ve hicles 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 pe rcent is used and employed in a skewed Beta distribution which produced a m ean 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.



### Greenhouse Gas Emissions Emissions of carbon dioxide (CO 2 ) and other greenhouse gases (GHG) occur throughout the process of producing and distributin g transportation fuels, as well as from fuel combustion itself. By reducing the volume of fuel consumed by passenger cars and light trucks, higher CAFE
standards will thus reduce GHG emis sions generated by fuel use, as well as throughout the fuel supply cycle. Lowering these emissions is like ly to slow the projec ted pace and reduce the ultimate extent of future changes in the global climate, thus reducing future economic damages that changes in the global climate would othe rwise cause. By reducing the probability that climate changes with potentially catastrophic economic or envir onmental impacts will occur, lowering GHG emissions may also result in ec onomic benefits that exceed the resulting reduction in the expected future economic costs ca used by gradual changes in the earth’s climatic systems. In Chapter VIII a full discussion of this issue, including alternat e estimates of values for Greenhouse gases is presented. We had to pick a number for the uncertainty analysis. We could have chosen any of the numbers discussed in Chapter VIII. We chose $2 per metric ton of

CO 2 emissions with a standard de viation of $1.00 per metric ton.

Table X-3 Summarizes the economic paramete rs used in the uncertainty analysis.X-8

Table X-3
Monte-Carlo Specific Parameters

Rebound Randomization Parameters Rebound Alpha Shape 15.0 Rebound Beta Shape 6.6

Rebound Scale -0.20

Rebound Base -0.05 Monopsony Randomization Parameters Monopsony Mean $0.266 Monopsony Standard Deviation $0.129

Price Shock Randomization Parameters
Price Shock Mean $0.116
Price Shock Standard Deviation $0.041 Military Security Randomization Parameters Military Security Mean $0.000 Military Security Standard Deviation $0.000

Carbon Dioxide Randomization Parameters
CO-2 Mean $2.00
CO-2 Standard Deviation $1.00

Default Cost and Effectiveness Variations

Cost Variation % 29%

Effectiveness Variation % 31%

Fuel Path Randomization Parameters

Low 5%

Reference 35% High 60%

Modeling Results – Trial Draws

Because of the complexity of the CAFE mode l, the computer time required to perform the uncertainty analysis was signifi cant. The uncertainty analysis conducted a total of 40,000 trials (20,000 for each discount rate) Figures X- 3 thr ough X-14 graphically illustrate the draw results for a sample of the 84 variables (40 technology e ffectiveness rates, 40 technology costs, the fuel price scenario, oil import externalities, the re bound effect, and CO2.) that were examined. Tables X-4 through X-8 list the draw results for each economic input, technology cost, and technology effectiveness.X-9

Figure X-3 Monte Carlo Draw Profile, Passenger Car Costs

Turbocharging and Downsizing

0 200 400 600 800 1000 1200 1400 1600

$668 $848 $1,028 $1,208 $1,388 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-10

Figure X-4 Monte Carlo Draw Profile, Passenger Car Effectiveness

Turbocharging and Downsizing

0 200 400 600 800 1000 1200 1400 1600

0.038 0.040 0.041 0.042 0.044

Fuel Consumption Reduction (gpm) 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-5 Monte Carlo Draw Profile, Passenger Cars, Costs

Conversion to Diesel following TRBDS

0 200 400 600 800 1000 1200 1400 1600 1800 2000

$1,910 $2,010 $2,110 $2,210 $2,310 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-11

Figure X-6 Monte Carlo Draw Profile, Passenger Cars, Effectiveness

Conversion to Diesel following TRBDS

0 200 400 600 800 1000 1200 1400 1600 1800 2000

0.051 0.056 0.061 0.066 0.071

Fuel Consumption Reduction (gpm) 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-7 Monte Carlo Draw Profile, Passenger Cars, Costs

Dual Clutch or Automated Manual Transmission

0 200 400 600 800 1000 1200 1400

$5 $57 $109 $161 $213 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-12

Figure X-8 Monte Carlo Draw Profile, Passenger Cars, Effectiveness

Dual Clutch or Automated Manual Transmission

0 200 400 600 800 1000 1200 1400

0.034 0.039 0.044 0.049 0.054

Fuel Consumption Reduction (gpm) 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-9
Monte Carlo Draw Profile

Pretax Fuel Price Path

Fuel Price Estimates

Low, 4.8% A verage,
35.5% High, 59.7%

0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0%X-13

Figure X-10
Monte Carlo Draw Profile

CO2 Cost ($/metric ton)

0 500 1000 1500 2000 2500

$0.07 $1.41 $2.75 $4.09 $5.43 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-11
Monte Carlo Draw Profile

Monopsony Cost ($/gal.)

0 500 1000 1500 2000 2500

$0.01 $0.18 $0.34 $0.51 $0.68 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-14

Figure X-12
Monte Carlo Draw Profile

Rebound Effect

0 500 1000 1500 2000 2500 3000 3500

-0.052 -0.092 -0.132 -0.172 -0.212 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-13
Monte Carlo Draw Profile

Price Shock Cost ($/gal.)

0 500 1000 1500 2000 2500 3000

$0.00 $0.06 $0.12 $0.18 $0.24 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-15

Figure X-14
Monte Carlo Draw Profile

Total Economic Cost of Petroleum ($/gal.)

0 500 1000 1500 2000 2500

$0.03 $0.21 $0.39 $0.57 $0.75 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Table X-4 Monte Carlo Draw Results, Economic Inputs

Economic Inputs Minimum Maximum Mean StdDev

Rebound Effect -0.247363 -0.058833 -0.186533 0.024108 Monopsony Cost 2.112E-05 0.8328859 0.270747 0.1210186

Price Cost Shock 1.944E-05 0.2958011 0.1160486 0.0402068

Total Economic Costs 0.0262398 0.9144824 0.3867956 0.1273687

CO2 Costs 0.000961 6.6922461 2.0517406 0.9371776X-16

Table X-5 Monte Carlo Draw Results, Passenger Car Technology Costs

Passenger Car Technology Costs Minimum Maximum Mean StdDev

Low Friction Lubricants $3.19 $7.28 $5.00 $0.48
Engine Friction Reduction $6.31 $58.79 $31.01 $6.03
VVT - Coupled Cam Phasing (CCP) on SOHC $37.89 $87.04 $60.99 $5.87
Discrete Variable Valve Lift (DVVL ) on SOHC $118.51 $275 .63 $188.81 $18.18
Cylinder Deactivation on SOHC $43.49 $101.67 $70.80 $6.82
VVT - Intake Cam Phasing (ICP) $36.84 $88.25 $60.99 $5.89
VVT - Dual Cam Phasing (DCP) $36.97 $89.25 $61.03 $5.84
Discrete Variable Valve Lift (DVVL ) on DOHC $115.55 $257 .50 $188.57 $18.29
Continuously Variable Valve Lift (CVVL) $172.36 $407.52 $283.34 $27.43
Cylinder Deactivation on DOHC $46.30 $97.20 $70.80 $6.83
Cylinder Deactivation on OHV $31.61 $71.54 $50.94 $4.93
VVT - Coupled Cam Phasing (CCP) on OHV $37.65 $88.45 $60.95 $5.90
Discrete Variable Valve Lift ( DVVL) on OHV $97.77 $224.79 $157.90 $15.45

Conversion to DOHC with DC P $222.89 $478.16 $353.58 $34.17
Stoichiometric Gasoline Direct Injection (GDI) $65.53 $111.74 $88.14 $5.64

Combustion Restart $84.90 $199.86 $141.17 $13.54
Turbocharging and Downsizing $681.50 $1,597.47 $1,122.99 $108.04
Exhaust Gas Recirculation (EGR) Boost $111.02 $237.59 $172.83 $16.67
Conversion to Diesel following TRBDS $1, 950.09 $2,351.85 $2,143.92 $47.08
Conversion to Diesel following CBRST $3, 238.68 $3,675.06 $3,440.37 $52.49
6-Speed Manual/Improved Internals $208.46 $457.04 $337.99 $32.85
Improved Auto. Trans. Controls/Externals $36.11 $85.05 $58.99 $5.70
Continuously Variable Transmission $186.55 $438.16 $300.16 $28.97 6/7/8-Speed Auto. Trans with Improved Internals $251.70 $474.10 $360.39 $26.52

Dual Clutch or Automated Manual Transmission $0.08 $259.88 $120.22 $35.88
Electric Power Steering $102.88 $122.11 $112.49 $2.49
Improved Accessories $166. 76 $214.06 $192.02 $6.31
12V Micro-Hybrid $268.05 $587.90 $436.94 $41.89
Higher Voltage/Improved Altern ator $51.12 $119.34 $84.00 $8.12
Belt mounted Integrated Starter Generato r $1,263.54 $2,822.47 $2,091.42 $200.61
Power Split Hybrid $2,195.51 $2,253.54 $2,225.28 $7.33
2-Mode Hybrid $7,451.27 $7,830.93 $7,645.98 $48.93
Plug-in Hybrid $15,563.84 $32,715.96 $24,095.03 $2,313.54
Material Substitution (1%) $0.84 $2.13 $1.50 $0.17
Material Substitution (2%) $0.86 $2.10 $1.50 $0.17X-17

Passenger Car Technology Costs Minimum Maximum Mean StdDev
Material Substitution (5%) $1.63 $4.45 $3.00 $0.33
Low Rolling Resistance Tires $5.55 $9.65 $7.50 $0.50
Low Drag Brakes $53.60 $121.49 $88.91 $8.62
Secondary Axle Disconnect - Ladder Frame $72.53 $162.54 $116.93 $11.40
Aero Drag Reduction $51.17 $130.84 $87.99 $9.38

Table X-6 Monte Carlo Draw Results, Passenger Car Fuel Economy Improvement Rates Passenger Car Fuel Economy Improvement
Rates Minimum Maximum Mean StdDev

Low Friction Lubricants 0.003081 0.006944 0.005004 0.000520
Engine Friction Reduction 0.008423 0.021196 0.015017 0.001680
VVT - Coupled Cam Phasing (CCP) on SOHC 0.006509 0.031585 0.019517 0.003163 Discrete Variable Valve Lift (DVVL) on

SOHC 0.006988 0.032878 0.019508 0.003169
Cylinder Deactivation on SOHC 0.024094 0.031399 0.027480 0.000833
VVT - Intake Cam Phasing (ICP) 0.008318 0.021437 0.014987 0.001672
VVT - Dual Cam Phasing (DCP) 0.019176 0.032757 0.025008 0.001668 Discrete Variable Valve Lift (DVVL) on

DOHC 0.007146 0.03144 2 0.019499 0.003197
Continuously Variable Valve Lift (CVVL) 0.011316 0.040263 0.025042 0.003351
Cylinder Deactivation on DOHC 0. 000001 0.006360 0.0 02498 0.000833
Cylinder Deactivation on OHV 0.03 7523 0.059210 0.0 47002 0.002660
VVT - Coupled Cam Phasing (CCP) on OHV 0.009449 0.015728 0 .012492 0.000833
Discrete Variable Valve Lift (DVVL) on OHV 0.001237 0.02999 4 0.015507 0.003511

Conversion to DOHC with DCP 0. 008036 0.030776 0.0 18013 0.002669
Stoichiometric Gasoline Direct Injection (GDI) 0.017140 0.032116 0.023978 0.001675

Combustion Restart 0.016894 0.025485 0.020999 0.001014
Turbocharging and Downsizing 0.038320 0.044068 0.041346 0.000737
Exhaust Gas Recirculation (EGR) Boos t 0.038821 0.040267 0.039498 0.000167
Conversion to Diesel following TRBDS 0.055095 0.072376 0 .063902 0.002208
Conversion to Diesel following CBRST 0.132909 0.144731 0 .138004 0.001357
6-Speed Manual/Improved Internals 0.002921 0.006953 0.004999 0.000519
Improved Auto. Trans. Controls/Externals 0.013493 0.027226 0.020011 0.001676
Continuously Variable Transmission 0.005850 0.024451 0.013511 0.002154
6/7/8-Speed Auto. Trans with Improved 0.011587 0.036830 0.024001 0.003343X-18

Passenger Car Fuel Economy Improvement
Rates Minimum Maximum Mean StdDev

Internals

Dual Clutch or Automated Manual
Transmission 0.034972 0.057801 0.046578 0.002969
Electric Power Steering 0.008506 0.022496 0.015024 0.001663
Improved Accessories 0.008457 0 .021425 0.01 4979 0.001674
12V Micro-Hybrid 0.021328 0.035888 0.028333 0.001894
Higher Voltage/Improved Alternator 0.001109 0.008370 0.004740 0.000908
Belt mounted Integrated Starter Genera tor 0.051607 0.063482 0.057622 0.001520
Power Split Hybrid 0.129323 0 .137372 0.13 3660 0.001073
2-Mode Hybrid 0.005196 0.022135 0.013360 0.001993
Plug-in Hybrid 0.599984 0.640456 0.619019 0.004634
Material Substitution (1%) 0.00 2063 0.005055 0.0 03499 0.000364
Material Substitution (2%) 0.00 2151 0.004818 0.0 03501 0.000362
Material Substitution (5%) 0.00 5825 0.014986 0.0 09997 0.001028
Low Rolling Resistance Tires 0.008153 0.021865 0.014995 0.001663
Low Drag Brakes 0.004202 0.010680 0.007507 0.000834
Secondary Axle Disconnect - Ladder Frame 0.009563 0.015715 0.012492 0.000834
Aero Drag Reduction 0.018163 0.031236 0.024991 0.001671

Table X-7 Monte Carlo Draw Results, Light Truck Technology Costs

Light Truck Technology Costs Minimum Maximum Mean StdDev

Low Friction Lubricants $3.19 $7.28 $5.00 $0.48
Engine Friction Reduction $6.31 $58.79 $31.01 $6.03 VVT - Coupled Cam Phasing (CCP) on SOHC $37.89 $87.04 $60.99 $5.87 Discrete Variable Valve Lift (DVVL) on SOHC $109.97 $255.76 $175.20 $16.87
Cylinder Deactivation on SOHC $46.07 $107.70 $75.00 $7.22
VVT - Intake Cam Phasing (ICP) $36.84 $88.25 $60.99 $5.89
VVT - Dual Cam Phasing (DCP) $36.97 $89.25 $61.03 $5.84 Discrete Variable Valve Lift (DVVL) on DOHC $107.22 $238. 93 $174.97 $16.97
Continuously Variable Valve Lift (CVVL) $154.68 $365.73 $254.28 $24.61
Cylinder Deactivation on DOHC $49.04 $102.97 $74.99 $7.24
Cylinder Deactivation on OHV $31.38 $71.02 $50.56 $4.89X-19

Light Truck Technology Costs Minimum Maximum Mean StdDev VVT - Coupled Cam Phasing (CCP) on OHV $37.65 $88.45 $60.95 $5.90 Discrete Variable Valve Lift (DVVL) on OHV $33.53 $77.09 $54.15 $5.30

Conversion to DOHC with DC P $210.08 $450.69 $333.27 $32.21 Stoichiometric Gasoline Direct Injection (GDI) $59.34 $101.19 $79.82 $5.11

Combustion Restart $84.90 $199.86 $141.17 $13.54
Turbocharging and Downsizing $619.49 $1,452.12 $1,020.81 $98.21
Exhaust Gas Recirculation (EGR) Boost $111.02 $237.59 $172.83 $16.67
Conversion to Diesel following TRBDS $3, 095.29 $3,732.99 $3,402.95 $74.73
Conversion to Diesel following CBRST $4, 327.81 $4,910.94 $4,597.32 $70.14
6-Speed Manual/Improved Internals $208.46 $457.04 $337.99 $32.85
Improved Auto. Trans. Controls/Externals $36.11 $85.05 $58.99 $5.70
Continuously Variable Transmission $186.55 $438.16 $300.16 $28.97 6/7/8-Speed Auto. Trans with Improved Internals $322.56 $607.58 $461.85 $33.98

Dual Clutch or Automated Manual Transmission $0.05 $172.00 $79.57 $23.75
Electric Power Steering $102.88 $122.11 $112.49 $2.49
Improved Accessories $166. 76 $214.06 $192.02 $6.31
12V Micro-Hybrid $299.01 $655.81 $487.41 $46.73
Higher Voltage/Improved Altern ator $51.12 $119.34 $84.00 $8.12
Belt mounted Integrated Starter Generato r $1,432.05 $3,198.90 $2,370.36 $227.37
Power Split Hybrid $2,819.76 $2,894.29 $2,858.00 $9.42
2-Mode Hybrid $10,623.90 $11,165.22 $10,901.52 $69.77
Plug-in Hybrid $15,697.59 $32,997.09 $24,302.08 $2,333.42
Material Substitution (1%) $0.84 $2.13 $1.50 $0.17
Material Substitution (2%) $0.86 $2.10 $1.50 $0.17
Material Substitution (5%) $1.63 $4.45 $3.00 $0.33
Low Rolling Resistance Tires $5.55 $9.65 $7.50 $0.50
Low Drag Brakes $53.60 $121.49 $88.91 $8.62
Secondary Axle Disconnect - Ladder Frame $72.53 $162.54 $116.93 $11.40
Aero Drag Reduction $51.17 $130.84 $87.99 $9.38X-20

Table X-8 Monte Carlo Draw Results, Light Tr uck Fuel Economy Improvement Rates

Light Truck Fuel Economy Improvement
Rates Minimum Maximum Mean StdDev

Low Friction Lubricants 0.003081 0.006944 0.005004 0.000520
Engine Friction Reduction 0.008423 0.021196 0.015017 0.001680
VVT - Coupled Cam Phasing (CCP) on SOHC 0.006509 0.031585 0.019517 0.003163 Discrete Variable Valve Lift (DVVL) on

SOHC 0.006988 0.032878 0.019508 0.003169
Cylinder Deactivation on SOHC 0.024094 0.031399 0.027480 0.000833
VVT - Intake Cam Phasing (ICP) 0.008318 0.021437 0.014987 0.001672
VVT - Dual Cam Phasing (DCP) 0.019176 0.032757 0.025008 0.001668 Discrete Variable Valve Lift (DVVL) on

DOHC 0.007146 0.03144 2 0.019499 0.003197
Continuously Variable Valve Lift (CVVL) 0.011316 0.040263 0.025042 0.003351
Cylinder Deactivation on DOHC 0. 000001 0.006360 0.0 02498 0.000833
Cylinder Deactivation on OHV 0.03 7523 0.059210 0.0 47002 0.002660
VVT - Coupled Cam Phasing (CCP) on OHV 0.009449 0.015728 0 .012492 0.000833
Discrete Variable Valve Lift (DVVL) on OHV 0.001237 0.02999 4 0.015507 0.003511

Conversion to DOHC with DCP 0. 008036 0.030776 0.0 18013 0.002669
Stoichiometric Gasoline Direct Injection (GDI) 0.017140 0.032116 0.023978 0.001675

Combustion Restart 0.016894 0.025485 0.020999 0.001014
Turbocharging and Downsizing 0.022433 0.025799 0.024205 0.000432
Exhaust Gas Recirculation (EGR) Boos t 0.038821 0.040267 0.039498 0.000167
Conversion to Diesel following TRBDS 0.044485 0.058439 0 .051596 0.001783
Conversion to Diesel following CBRST 0.107210 0.116746 0 .111320 0.001094
6-Speed Manual/Improved Internals 0.002921 0.006953 0.004999 0.000519
Improved Auto. Trans. Controls/Externals 0.013493 0.027226 0.020011 0.001676
Continuously Variable Transmission 0.005850 0.024451 0.013511 0.002154 6/7/8-Speed Auto. Trans with Improved
Internals 0.011587 0.036830 0.024001 0.003343

Dual Clutch or Automated Manual
Transmission 0.025527 0.042190 0.033998 0.002167
Electric Power Steering 0.008506 0.022496 0.015024 0.001663
Improved Accessories 0.008457 0 .021425 0.01 4979 0.001674
12V Micro-Hybrid 0.025690 0.043228 0.034128 0.002282
Higher Voltage/Improved Alternator 0.000993 0.007492 0.004242 0.000813
Belt mounted Integrated Starter Genera tor 0.054636 0.067207 0.061003 0.001610
Power Split Hybrid 0.136395 0 .144884 0.14 0969 0.001132
2-Mode Hybrid 0.017174 0.073159 0.044157 0.006589
Plug-in Hybrid 0.600961 0.641500 0.620027 0.004641X-21

Light Truck Fuel Economy Improvement
Rates Minimum Maximum Mean StdDev
Material Substitution (1%) 0.00 2063 0.005055 0.0 03499 0.000364
Material Substitution (2%) 0.00 2151 0.004818 0.0 03501 0.000362
Material Substitution (5%) 0.00 5825 0.014986 0.0 09997 0.001028
Low Rolling Resistance Tires 0.008153 0.021865 0.014995 0.001663
Low Drag Brakes 0.004202 0.010680 0.007507 0.000834
Secondary Axle Disconnect - Ladder Frame 0.009563 0.015715 0.012492 0.000834
Aero Drag Reduction 0.018163 0.031236 0.024991 0.001671

Modeling Results – Output

Tables X-9 and X-10 summarize the modeling results fo r fuel saved, total costs, societal benefits, and net benefits for passenger cars and trucks respectiv ely under a 7% discount rate. They also indicate the probability that net benefits exceed ze ro. These results are also illustrated in Figures X-15 through X-18 for passenger cars under Optimized CAFE at 7 percent. Although not shown here, the general shape of the resulting output distributions ar e similar for the light trucks. 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 draw n from the Low Oil Price scenar io and one quarter were drawn from the High Oil Price scenario. This produc es three separate humps which reflect the increasing impact on benefits from the three prog ressively higher oil price scenarios. The Low Oil scenario is close enough to th e Forecast scenario that the 2 hu mps visually begin to merge. However, the difference between the High Oil Pri ce 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 disc ussions summarize the range of results presented in these tables for the combin ed passenger car and light truck across both the 7 percent (typically th e lower range) and 3 pe rcent (typically upper range) discount rates 321

.

Fuel Savings : The analysis indicates that MY 2011 vehicles (both passe nger cars and light trucks) will experience between 732 million and 1,114 million gallons of fuel savings over their useful lifespan.

Total Costs : The analysis indicates th at owners of MY 2011 passenger cars and light trucks will pay between $760 million and $2,235 million in higher ve hicle prices to purchase vehicles with improved fuel efficiency

321 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-22

Societal Benefits: The analysis indicates that change s to MY 2011 passenger cars and light trucks to meet the proposed CAFE standards will produce overall societal benefits valued between $1,003 million and $2,229 million.

Net Benefits : The uncertainty analysis indicates that the net impact of the higher CAFE requirements for MY 2011 passenger cars and light trucks will range from a net loss of $913 million to a net benefit of $1,224 million. There is at least an 80 percent certainty (the lower of the passenger car and light truc k certainty levels) that change s made to MY 2011 vehicles to achieve the higher CAFE standards will produce a net benefit.X-23

Table X-9 Uncertainty Analysis Results, Passenger Cars (7% Discount Rate)

MY 2011 Mean Low High Fuel Saved (mill. gall.) 445 383 566 Total Cost ($mill.) 496 332 776 Societal Benefits ($mill.) 868 512 1,183 Net Benefits ($mill.) 372 (121) 734 % Certainty Net Ben. > 0 100%

Table X-10 Uncertainty Analysis Results, Light Trucks (7% Discount Rate)

MY 2011 Mean Low High Fuel Saved (mill. gall.) 407 349 548 Total Cost ($mill.) 673 428 1,459 Societal Benefits ($mill.) 788 491 1,046 Net Benefits ($mill.) 115 (792) 490 % Certainty Net Ben. > 0 80%

Table X-11 Uncertainty Analysis Results, Pa ssenger Cars and Light Trucks (7% Discount Rate)

MY 2011 Mean Low High
Fuel Saved (mill. gall.) 852 732 1114 Total Cost ($mill.) 1169 760 2235
Societal Benefits ($mill.) 1656 1003 2229
Net Benefits ($mill.) 487 -913 1224X-24

Figure X-15 Model Output Profile

Cars: Fuel Savin g s for "Optimized Reformed Standards" (2015) at 7% Discount Rate

0 200 400 600 800 1000 1200 1400

3,

951, 180

4,

097, 080

4,242,980 4,388 , 880

4,

534,7 80

4,680 , 680

4,

826, 580

4,972,480 5,118,380

5,

264, 280 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-16 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

4,552 5,312 6,072 6,832 7,592 8,352 9,112 9,872 10,632 11,392 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %X-25

Figure X-17 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

6,763 7,078 7,393 7,708 8,023 8,338 8,653 8,968 9,283 9,598 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %

Figure X-18 Model Output Profile

Cars: Net Benefits for "Optimized Reformed Standards" (2015) at 7% Discount Rate

0 200 400 600 800 1000 1200 1400

-3,733 -2,898 -2,063 -1,228 -393 442 1,277 2,112 2,947 3,782 0% 20% 40% 60% 80% 100% 120%

Frequency Cumulative %XI-1



### XI. REGULATORY FLEXIBILITY ACT AND UNFUNDED MANDATES
REFORM ACT ANALYSIS

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 ru les 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) desc ribing 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 acti on 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 feas ible, an estimate of the numbe r of small entities to which the final rule will apply;

4. A description of the proj ected reporting, recording k eeping and other compliance requirements of a final rule including an esti mate 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 exte nt practicable, of all releva nt Federal rules which may duplicate, overlap or conflict with the final rule;

6. Each final regulatory flexibility analysis shall also contain a descrip tion 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 acti on 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 up date passenger car fuel economy standards. The Energy Independence and Security Act (EISA) ma ndates the setting of separate standards for passenger cars and for light trucks at levels suffici ent to ensure that the average fuel economy of the combined fleet of all passenger cars and light trucks sold by a ll manufacturers in the U.S. in model year 2020 equals or exceeds 35 miles per gallon.

3. Description and estimate of the number of sm all entities to which the final rule will apply
The final rule will affect motor vehicle manufact urers. There are no light truck manufacturers that are small businesses. However, there ar e 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 st ated in 13 CFR 121.201, is the number of employees in the firm. For establishments primarily enga ged in manufacturing or assembling automobiles, light and heavy duty trucks, bus es, motor homes, or motor vehi cle 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. Those manu facturers that currently don’t meet the 27.5 mpg standard can petition the agency for relief. If the standard is raised, it ha s no meaningful impact on these manufacturers, they still must go through the same process and petition for relief. Other small manufacturers (Tesla and Fisker) ma ke electric vehicles or hybrid vehicles that will pass the final
rule.

Currently, there are six small passenger car motor vehicle manufacturers in the United States. Table X1-1 provides information about the 6 sma ll domestic manufacturers in MY 2007. All are small manufacturers, having much less than 1,000 employees.XI-3

Table XI-1
Small Vehicle Manufacturers

Manufacturer Employees Estimated Sales Sale Price Range Est. Revenues*

Fisker
Automotive** N/A 15,000 projected $80,000 N/A

Mosler
Automotive 25 20 $189,000 $2,000,000

Panoz Auto Development Company 50 150 $90,000 to $125,000 $16,125,000

Saleen Inc. 170 1,000 # $39,000 to $59,000 $49,000,000

Saleen Inc. 170 16 ## $585,000 $9,000,000

Standard
Taxi*** 35 N/A $25,000 $2,000,000 Tesla Motors,

Inc. 250 2,000 $65,000 to $100,000 N/A * Assuming an average sales price from the sales price range. ** Fisker Automotive is a jo int venture of Quantum Fuel Systems Technologies Worldwide, Inc. and Fisker Coachbuild, LLC. *** Standard Taxi is a subsidiary of the Ve hicle Production Group LLC. 35 employees is the
total for VPG LLC.

# Ford Mustang Conversions

The agency has not analyzed the impact of the final rule on these small manufacturers individually. However, assuming those that do no t meet the final rule w ould petition the agency, rather than meet the final rule, the cost is not expected to be substantial.

4. A description of the projected reporting, record keeping and ot her 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 ne cessary for preparation of the report or record. This final rule includes no new requirements fo r reporting, record keeping of other compliance requirements.

5. An identification, to the extent practicable, of all relevant Fe deral 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.XI-4

6. A description of any significant alternatives to the final rule which accomplish the stated objectives of applicable statutes and which mi nimize 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.

A. Unfunded Mandates Reform Act

The Unfunded Mandates Reform Act of 1995 (Public Law 104-4) requires ag encies to prepare a written assessment of the costs, benefits, and othe r effects of proposed or final rules that include a Federal mandate likely to result in the expenditures by States, lo cal or tribal governments, in the aggregate, or by the private sector, of mo re 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 2007 results in $130 milli on (119.816/92.106 = 1.30). The assessment may be included in conjunction with othe r assessments, as it is here.