Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles (2015) / Chapter Skim
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10 Overall Assessment of CAFE Program Methodology and Design
10 Overall Assessment of CAFE Program Methodology and Design
Pages 337-368
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From page 337... ...
The relevant fuel economy or GHG target for a vehicle lower standard, thereby undermining some of the fuel savwould be calculated based on a mathematical formula that 2 CAFE standards for light trucks for MY 2008-2011 included a reform to 1 NHSTA describes the "augural" MYs 2022-2025 standards as not final the structure for CAFE standards for light trucks and gave manufacturers the and "as representative of what levels of stringency the agency currently option for MY 2008-2010 to comply with the reformed standard or to combelieves would be appropriate in those model years, based on the informa- ply with the unreformed standard. The reformed standard was based on the tion before us today." vehicle footprint.
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From page 338... ...
In fact, the earlier CAFE standards were Shifts in the Car/Light Truck Mix also attribute-based -- vehicle class in that case -- with one standard for passenger cars and a less stringent one for light Separate car and light-truck standards might incentivize trucks. The lower standard for trucks may have helped to ac- a shift to light trucks from cars.
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From page 339... ...
The fuel economy target increases for a given vehicle footprint as the standards become more stringent over time. 10.1a FIGURE 10.1b Fuel economy target vs.
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From page 340... ...
The figures show a good deal of variation in weight for economics literature on elasticities, but it is unclear how reli- both cars and trucks, with light trucks substantially heavier able these are. Estimates tend to show that the vehicle size/ than cars.
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From page 341... ...
OVERALL ASSESSMENT OF CAFE PROGRAM METHODOLOGY AND DESIGN 341 FIGURE 10.2a Changes in the distribution of car weights in MY 1975-2007. R02853 CAFEII 10.2a.eps FIGURE 10.2b Changes in the distribution of light truck weights in MY 1975-2007.
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From page 342... ...
The principle under fully tradable fuel average cars is associated with a small increase in fatality economy and emissions credits is that there is a target total risk, there is a large range in risk for cars of the same mass, amount of fuel consumption and greenhouse gas emissions even after accounting for differences in vehicles, drivers, reductions over a period of time, but when those reductions and crash circumstances (Section 4 of Wenzel 2012)
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From page 343... ...
. Cars and trucks A manufacturer faces two standards under both the CAFE are assumed to have different lifetime VMTs, estimated by and GHG regulations, one for cars and a more lenient one NHTSA at 195,264 miles for passenger cars and 225,865 for trucks.3 Manufacturers can average fuel consumption or miles for light trucks.
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From page 344... ...
R02853 CAFEII 10.4.eps reporting to the EPA, about half of the roughly 20 manufac- ing the 1990s and was replaced by SUVs and CUVs clasturers reported earning credits for overcompliance of their sified as light trucks, making it easier for manufacturers to car fleets, and the other half were in deficit due to under- meet their car standards. It must be noted that some of the compliance.
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From page 345... ...
The standards through 2011 did not depend on miles of cars and of light trucks in the 2012 to 2016 rule, vehicle footprint, and the early credit accumulation will tend though VMT assumptions are now apparently the same for to favor smaller, lighter vehicle manufacturers. The number the 2017-2025 rule.
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From page 346... ...
stringent FFV credit system after 2015. Described in more de NHTSA and EPA have differing provisions for calculat- tail later in the chapter, beginning in 2016, the compliance ing compliance fuel economy or GHG emissions and hence GHG emissions of FFVs will assume they operate on 100 perc redits earned for production of flex-fuel vehicles (FFVs)
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From page 347... ...
. This is reflected in number of credits that can be transferred between cars and the systematically-adjusted lower fuel economy values the light trucks.
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From page 348... ...
For example, the current gap in fuel economy the Clean Air Act to modify the emissions tests. The three between the certification two-cycle test and the adjusted label additional test procedures were adopted by EPA in 1996 five-cycle fuel economy values is approximately 20 percent TABLE 10.2 Comparison of EPA Test Cycles Test Schedule Driving Schedule Attributes City Highway High Speed AC Cold Temp Trip Type Low speeds in stop- Free-flow traffic at Higher speeds; harder AC use under hot City test w/ colder and-go urban traffic highway speeds acceleration & braking ambient conditions outside temperature Top Speed 56.7 mph 60 mph 80 mph 54.8 mph 56.7 mph Average Speed 21.2 mph 48.3 mph 48.4 mph 21.2 mph 21.2 mph Max.
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From page 349... ...
Accu A valid understanding of the relationship between testracy measures the degree to which the fuel economy esti- cycle and real-world fuel economy based on in-use data mates deviate from the individual fuel economies achieved could fill three important information gaps for regulators by individual drivers in actual driving. For the purposes of and consumers: ensuring that the fuel economy standards achieve the goals of reducing light-duty vehicle petroleum consumption, • Unbiased estimates necessary for quantifying the benGHG emissions, and fuel costs, unbiasedness is sufficient.
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From page 350... ...
concluded important to estimating the costs and benefits of the fuel that fuel consumption of passenger cars was 23 percent economy standards. Deviation of real-world fuel economy higher than combined city/highway test estimates and that from EPA window sticker value, as well as from the CAFE the comparable number for light trucks was 27.9 percent.
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From page 351... ...
and then dividing it by the same 0.15 "fuel content" factor used for alcohol and natural gas-powered Dedicated Alternative Fuel Vehicles vehicles.8 Eg is calculated as follows:9 For dedicated liquid alternative fuel vehicles (including 6 The methanol or ethanol high-blend fuels)
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From page 352... ...
is also given formation on the development of this SAE utility factor approach, see http:// the same 0.15 fuel content factor as other liquid alternative fuels such as www.SAE.org, specifically SAE J2841 ‘‘Utility Factor Definitions for PlugE85 and M85. In Hybrid Electric Vehicles Using Travel Survey Data,'' September 2010.
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From page 353... ...
Mild and strong where HEV pickup trucks are defined based on energy flows to the UFUrban is the utility factor-weighted fuel economy for high-voltage battery. The performance-based incentives are the urban drive cycle; for other promising technologies besides hybridization that UFU is the urban utility factor, essentially the fraction can provide significant reductions in GHG emissions and of urban driving expected to be displaced by an AFV of fuel consumption, such as lightweight materials.
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From page 354... ...
Based on the fuel economy standards for passenger cars "linking the CAFE credit to actual alternative fuel used." in the MY 2017-2025 Final Rule, the committee estimates GAO (2007) recommended that the dual-fuel program should
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From page 355... ...
credit to more accurately reflect how often these vehicles Data on the performance of vehicle components and systems, are actually run on alternative fuels could be appropriate." including engine maps, aerodynamic drag coefficients, and Adoption of the "utility factor" method to credit PHEVs other information, are inputs to the full vehicle simulaand dual-fuel CNG vehicles is an improvement over the tion model. The full vehicle simulation model predicts the previous method of assuming a 50/50 split.
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From page 356... ...
The sales and class/model mix over time. The 2017 reference fleet committee developed Figure 10.7 to aid in its understanding was also used to form the control case, in which technoloof the relationship among the null vehicle, baseline fleet, gies were added to increase fuel economy and reduce GHG reference fleet, reference case, and control case.
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From page 357... ...
Vehicle model during 2017-2025 standards 2017 vehicle model, futured to 2025 Costs and benefits of the rule are assessed "Null" Vehicle between the Control and Reference Case. Standard Setting Process FIGURE 10.7 Schematic illustrating the Agencies' definition of null vehicles, 2010 baseline fleet, 2017 reference fleet, reference case, and control case used to evaluate the CAFE/GHG standards.
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From page 358... ...
. The Agencies have made substantial progress toward the Estimating the impacts of technologies with the potential goal of full system simulation modeling for every important to reduce fuel consumption and greenhouse gas emissions is technology pathway and for every vehicle class.
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From page 359... ...
Finally, due to resource limitations, for the baseline and reference fleets. These results are used full vehicle simulation modeling is not feasible for every by the OMEGA and Volpe models in estimating compliance one of the approximately 1,000 vehicles in the baseline or with the fuel economy and emissions standards.
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From page 360... ...
. Both models apply technologies to the baseline of reduced petroleum consumption, and health improveand reference fleets in order of cost-effectiveness, subject to ments due to particulate matter reductions.14 There are also constraints to represent availability, applicability, and engi- some small external costs in terms of more congestion and neering logic.
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From page 361... ...
The may lead to estimates that are uncertain but it does not imply reasoning was that if one includes the full global benefit zero cost as assumed in the Final Rule (EPA/NHTSA 2012a, of reduced U.S. GHG emissions, one must also take the 63088)
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From page 362... ...
assumed discount rates, there is a high degree of certainty (99 percent) that higher CAFE standards will produce a net Reconciling GHG and CAFE Treatment of societal benefit in each of the combined fleet model years Alternative Fuel Vehicles covered by this rule.
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From page 363... ...
While alternative fuels can lead FINDINGS AND RECOMMENDATIONS to major discrepancies between the CAFE and GHG benefits, diesel vehicles also present a complication. Diesel combus- Finding 10.1 In the current assessment of the effects of tion results in more carbon dioxide emitted per gallon than the new rules, the footprint standard is assumed to have gasoline, so a diesel vehicle that meets the CAFE target for no effect on vehicle size, or on the mix of vehicle size and its size would exceed its GHG target.
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From page 364... ...
Recommendation 10.5 The CAFE FFV treatment that asFinding 10.4 The existing two-cycle certification tests sumes 50 percent alternative fuel usage should be phased out are not a sufficiently accurate representation of real-world as planned within the 2017-2025 CAFE regulation. driving behavior where the gap between the two-cycle and five-cycle tests is 20 percent for conventional vehicles and Finding 10.7 The current CAFE program uses a 0.15 divisor 30 percent for HEVs.
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From page 365... ...
If sufficient data do not exist, usage should recognizes that with differing statutory authorities come be monitored and treatment modified as appropriate. different requirements that are reflected in the compliance models, the treatment of alternative fuels, and the credit Finding 10.8 The Agencies' analyses of benefits and costs systems.
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From page 366... ...
2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas http://www.arb.ca.gov/regact/2013/zev2013/zev2013isor.pdf. Emissions and Fuel Economy Standards; Final Rule.
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From page 367... ...
Economy for MY 2017-MY2025 Passenger Cars and Light Trucks. Jacobsen, M
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From page 368... ...
2014. Fuel Consumption Survey.
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