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The Corporate Average Fuel Economy (CAFE) standards are regulations in the United States, first enacted by the U.S. Congress in 1975,〔(【引用サイトリンク】title=CAFE Overview: "What is the origin of CAFE?" )〕 in the wake of the Arab Oil Embargo, to improve the average fuel economy of cars and light trucks (trucks, vans and sport utility vehicles) produced for sale in the United States. ==Overview of CAFE== The Energy Policy and Conservation Act (EPCA), as amended by the 2007 Energy Independence and Security Act (EISA), requires that the U.S. Department of Transportation (DOT) establish standards separately for passenger automobiles (passenger cars) and nonpassenger automobiles (light trucks) at the maximum feasible levels in each model year, and requires that DOT enforce compliance with the standards. DOT has delegated these responsibilities to the National Highway Traffic Safety Administration (NHTSA). Through EPCA and EISA, U.S. law (49 U.S. Code § 32919) also requires that "a State or a political subdivision of a State may not adopt or enforce a law or regulation related to fuel economy standards or average fuel economy standards". The CAFE achieved by a given fleet of vehicles in a given model year is the production-weighted harmonic mean fuel economy, expressed in miles per U.S. gallon (mpg), of a manufacturer's fleet of current model year passenger cars or light trucks with a gross vehicle weight rating (GVWR) of 8,500 pounds (3,856 kg) or less (but also including medium-duty passenger vehicles—such as large sport-utility vehicles and passenger vans—with GVWR up to 10,000 pounds), produced for sale in the United States. The CAFE standards in a given model year define the CAFE levels that manufacturers' fleets are required to meet in that model year, specific levels depending on the characteristics and mix of vehicles produced by each manufacturer. If the average fuel economy of a manufacturer's annual fleet of vehicle production falls below the applicable requirement, the manufacturer must either apply sufficient CAFE credits (see below) to cover the shortfall or pay a penalty, currently $5.50 USD per 0.1 mpg under the standard, multiplied by the manufacturer's total production for the U.S. domestic market. Congress established both of these provisions explicitly in EPCA, as amended in 2007 by EISA. In addition, a Gas Guzzler Tax is levied on individual passenger car models (but not trucks, vans, minivans, or SUVs) that get less than . Starting in 2011 the CAFE standards are newly expressed as mathematical functions depending on vehicle footprint, a measure of vehicle size determined by multiplying the vehicle’s wheelbase by its average track width. A complicated 2011 mathematical formula was replaced starting in 2012 with a simpler inverse-linear formula with cut-off values. 〔(【引用サイトリンク】 publisher = NHTSA )〕 CAFE footprint requirements are set up such that a vehicle with a larger footprint has a lower fuel economy requirement than a vehicle with a smaller footprint. For example, the 2012 Honda Fit with a footprint of must achieve fuel economy (as measured for CAFE) of , equivalent to a published fuel economy of , while a Ford F-150 with its footprint of must achieve CAFE fuel economy of , i.e., published. CAFE 2016 target fuel economy of 34.0 MPG (44 sq. ft. footprint) compares to 2012 advanced vehicle performance of Prius hybrid on the compliance test cycles: 70.7 MPG, Plug-in Prius hybrid: 69.8 MPGe and LEAF electric vehicle: 141.7 MPGe. The compliance fuel economy of plug-in electric vehicles such as the Plug-in Prius or LEAF is complicated by accounting for the energy used in generating electricity. In 2012, the LEAF's compliance fuel consumption was considered to be 0 gal/mi, or infinite fuel economy, as it uses no liquid fuel on board, and that of the Plug-in Prius was also adjusted for the portion of vehicle energy use originating from the electric grid. CAFE has separate standards for "passenger cars" and "light trucks", despite the majority of "light trucks" actually being used as passenger cars. The market share of "light trucks" grew steadily from 9.7% in 1979 to 47% in 2001 and remained in 50% numbers up to 2011. 〔(【引用サイトリンク】 publisher = NHTSA )〕 More than 500,000 vehicles in the 1999 model year exceeded the GVWR cutoff and were thus omitted from CAFE calculations.〔(【引用サイトリンク】 publisher = NHTSA )〕 More recently, coverage of medium duty trucks has been added to the CAFE regulations starting in 2012, and heavy duty commercial trucks starting in 2014. The National Highway Traffic Safety Administration (NHTSA) regulates CAFE standards and the U.S. Environmental Protection Agency (EPA) measures vehicle fuel efficiency. U.S. Congress specifies that CAFE standards must be set at the "maximum feasible level" given consideration for: # technological feasibility; # economic practicality; # effect of other standards on fuel economy; # need of the nation to conserve energy. Historically, the EPA has encouraged consumers to buy more fuel efficient vehicles, while the NHTSA expressed concerns that smaller, more fuel efficient vehicles may lead to increased traffic fatalities.〔(【引用サイトリンク】 publisher = United States Environmental Protection Agency )〕 Thus higher fuel efficiency was associated with lower traffic safety, intertwining the issues of fuel economy, road-traffic safety, air pollution, and climate change. In the mid-2000s, increasing safety of smaller cars and the poor safety record of light trucks began to reverse this association. Nevertheless, in 2008, the on-road vehicle fleets in the United States and Canada had the lowest overall average fuel economy among first world nations: in North America, versus in the European Union and was even higher in Japan, according to data as of 2008. Furthermore, despite general opinion that larger and heavier (and therefore relatively fuel-uneconomical) vehicles are safer, the U.S. traffic fatality rate—and its trend over time is higher than some other western nations, although it has recently started to gradually decline at a faster rate than in previous years. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Corporate Average Fuel Economy」の詳細全文を読む スポンサード リンク
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