Download Corporate Average Fuel Economy for MY 2011 Passenger Cars and Light Trucks PDF

TitleCorporate Average Fuel Economy for MY 2011 Passenger Cars and Light Trucks
LanguageEnglish
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Document Text Contents
Page 1

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 2009

Page 2

TABLE 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 ENHANCING 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 SENSITIVITY ANALYSES ...................................................IX-1

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

XI. REGULATORY FLEXIBILITY ACT AND UNFUNDED MANDATES REFORM ACT

ANALYSIS................................................................................................................................XI-1

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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 for 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-cylinder engines, 50 percent of the V8 engine
conversion costs were assumed and one additional cam phasing system yielding an
incremental cost including a 1.5 RPE factor of $373.

For fuel economy effectiveness, NHTSA estimated 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 confidential 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 confidential manufacturer comment. For the final rule the upper
bound stated in the NPRM was reduced because DCP will give less improvement than
CVVL compared to an engine that already has cylinder deactivation and CCP applied.
NHTSA estimates the incremental fuel consumption effectiveness at 1 to 2.6 percent
independent of the number of engine cylinders.

There are no class-specific applications of this technology. In the NPRM, NHTSA
proposed raising the phase-in cap to 20 percent 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 rates 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 for the fuel economy effectiveness with
stoichiometric DI systems. The compression ratio increase comes about as a result of the
in-cylinder air charge cooling that 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 improves the full load torque. The improved full
load torque capability of GDI engines can have a secondary effect on fuel economy by
enabling engine downsizing, thereby reducing fuel consumption.

Two operating strategies can be used in gasoline DI engines, characterized by the mixture
preparation strategy. One strategy is to use homogenous charge where fuel is injected

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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 aftertreatment system can be a relatively low cost,
conventional three-way catalyst. Another strategy is to use stratified charge where fuel is
injected late in the compression stroke with single or multiple injections. The aim here is
to produce an overall lean, stratified 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 significantly improves efficiency by
reducing pumping work, but requires a relatively high cost lean NOx trap in the exhaust
aftertreatment system.

For purposes of this rulemaking, only homogeneous charge stoichiometric DI systems
were considered, due to the anticipated unavailability of low 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, stating that lean burn DI engines
cannot function in the absence of ultra-low sulfur gasoline. Lean NOx 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 from DI technology is therefore cumulative to
technologies that target pumping losses, such as the VVT and VVLT technologies. The
Sierra Research report stated that Sierra Research could not determine from the NPRM
decision trees if VVLT technologies were retained when SGDI was applied. To clarify,
as the model progresses through the decision trees, technologies preceding SGDI are
retained in the cumulative effectiveness and cost.

In the NPRM, NHTSA estimated the incremental fuel consumption effectiveness for
naturally aspirated SGDI164 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 engine and give up to a 5.8 percent increase in
efficiency. Other published literature reports a 3 percent effectiveness for SGDI,165 and
another source reports a 5 percent improvement on the NEDC drive cycle.166
Confidential manufacturer data submitted in response to the NPRM reported an
efficiency effectiveness range of 1 to 2 percent. 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_Symposium/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.

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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 joint venture of Quantum Fuel Systems Technologies Worldwide,
Inc. and Fisker Coachbuild, LLC.
*** Standard Taxi is a subsidiary of the Vehicle 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 not meet the final rule would 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 other compliance requirements of
a final rule including an estimate of the classes of small entities which will be subject to the
requirement and the type of professional skills necessary for preparation of the report or record.
This final rule includes no new requirements for reporting, record keeping of other compliance
requirements.

5. An identification, to the extent practicable, of all relevant Federal rules which may duplicate,
overlap, or conflict with the final rule
We know of no Federal rules which duplicate, overlap, or conflict with the final rule.

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XI-4

6. A description of any significant alternatives to the final rule which accomplish the stated
objectives of applicable statutes and which minimize any significant economic impact of the
final rule on small entities.

There are no other alternatives that can achieve the stated objectives without installing fuel
economy technologies into the vehicle.


A. Unfunded Mandates Reform Act

The Unfunded Mandates Reform Act of 1995 (Public Law 104-4) requires agencies to prepare a
written assessment of the costs, benefits, and other effects of proposed or final rules that include
a Federal mandate likely to result in the expenditures by States, local or tribal governments, in
the aggregate, or by the private sector, of more than $100 million annually (adjusted annually for
inflation with base year of 1995). Adjusting this amount by the implicit gross domestic product
price deflator for 2007 results in $130 million (119.816/92.106 = 1.30). The assessment may be
included in conjunction with other assessments, as it is here.

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