17 November 2011

The US Environmental Protection Agency (EPA) and the Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) jointly issued a proposed rule that would establish greenhouse gas (GHG) emission and corporate average fuel economy (CAFE) standards for model year (MY) 2017-2025 light-duty vehicles, extending and strengthening the program for MY 2012-2016 vehicles. The proposed standards are projected to require—on an average industry fleet wide basis—163 g/mile (101 g/km) of CO2 in MY 2025, which is equivalent to 54.5 mpg (4.32 L/100 km). The projected MY 2025 CAFE standard is 49.6 mpg (4.74 L/100 km).

The proposal introduces a set of fleet-wide average CO2 emission standards for cars and light trucks. These standards are based on CO2 emissions-footprint curves, where each vehicle has a different CO2 emissions compliance target depending on its footprint value—a parameter related to the size of the vehicle. Generally, the larger the vehicle footprint, the higher the corresponding vehicle CO2 emissions target. Manufacturers are not compelled to build vehicles of any particular size or type. Rather, each manufacturer will have its own fleet-wide standard that reflects the vehicles it chooses it produce. The following table shows the projected fleet-wide CO2 emission targets under the footprint-based approach.

Projected Fleet-Wide CO2 And Fuel Economy Compliance Levels
Vehicle Category & StandardModel Year
Passenger cars CO2, g/mi213202192182173165158151144
CAFE mpg40.041.443.044.746.648.851.053.556.0
Light trucks CO2, g/mi295285277270250237225214203
CAFE mpg29.430.030.631.233.334.936.638.540.3
Combined Cars & Trucks CO2, g/mi243232223213200190181172163
CAFE mpg35.336.437.538.840.942.945.047.349.6

The proposal also upholds the emission standards for CH4 and N2O already in place (0.030 g/mi and 0.010 g/mi, respectively). Manufacturers can (1) comply with these limits or (2) include their CH4 and N2O emissions, on an CO2-equivalent basis, in their fleet average CO2 calculation. Some changes are proposed for the calculations under the CO2-equivalent compliance option.

The proposal provides several compliance flexibilities for manufacturers:

  • Credit Banking and Trading—EPA is proposing to continue the same program for averaging, banking, and trading of credits established in the MY 2012-2016 program. Credits may be carried forward, or banked, for five years, or carried back three years to cover a deficit in a previous year. A manufacturer may transfer credits across all vehicles it produces, both cars and light trucks. Trading of credits between companies would also be permitted. To facilitate the transition to the 2017-2025 standards, EPA is proposing an additional CO2 credit carry-forward provision, allowing credits generated from MY 2010 through 2016 to be used through MY 2021.
  • Air Conditioning Improvement Credits—As with the MY 2012-2016 program, manufacturers will be able to generate CO2-equivalent credits for improvements in air conditioning (A/C) systems, both for approaches that reduce tailpipe CO2 through efficiency improvements and for reduced refrigerant leakage through better components and through the use of alternative refrigerants with lower global warming potential.
  • Off-Cycle Credits—Credits can be generated by off-cycle technologies, such as solar panels on hybrids, adaptive cruise control or active aerodynamics. For MY 2017 and later, EPA is proposing a pre-approved list of technologies and credit values.
  • Incentives for Electric Vehicles, Plug-in Hybrid Electric Vehicles, and Fuel Cell Vehicles—To facilitate early market penetration of advanced vehicle technologies, EPA is proposing an incentive multiplier for compliance purposes for all electric vehicles (EVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell vehicles (FCV) sold in MY 2017 through 2021. EVs and FCVs would start with a multiplier value of 2.0 in MY 2017, phasing down to a value of 1.5 in MY 2021. PHEVs would start at a multiplier value of 1.6 in MY 2017 and phase down to a value of 1.3 in MY 2021. There is no multiplier for MYs 2022-2025.

    For EVs, PHEVs (electricity usage) and FCVs, EPA is proposing to set a value of 0 g/mi for the tailpipe compliance value. Beginning from MY 2022, the 0 g/mi limit would only be allowed up to a per-company cumulative sales cap, above which manufacturers would be required to account for the net upstream GHG emissions for the electric portion of operation, using accounting methodologies set out in the rule.

  • Treatment of Compressed Natural Gas (CNG), Plug-in Hybrid Electric Vehicles (PHEVs), and Flexible Fuel Vehicles (FFVs)—EPA is proposing a methodology for determining CO2 levels for plug-in hybrid electric vehicles (PHEVs) and dual fuel compressed natural gas (CNG) vehicles based on the recognition that the consumer will likely use the cheaper fuel as much as possible. EPA is proposing to use the SAE “utility factor” methodology (based on vehicle range on the alternative fuel and typical daily travel mileage) to determine the assumed percentage of operation on gasoline and percentage of operation on the alternative fuel (a utility factor would not be used for flexible fueled vehicles (FFVs) using E-85 and gasoline).
  • Incentives for Hybridization for Full-Size Pick-Up Trucks—EPA is proposing an additional CO2 per vehicle credit for mild and strong hybrid electric (HEV) full size pickup trucks if this technology is utilized across a designated percentage of a manufacturers’ full size pickup trucks.

Comments on the proposal will be accepted for 60 days from its date of publication in the Federal Register.

Source: US EPA