technologies can reduce emissions to meet these levels. Vehicles powered by fuel cells, hybrid electric drive trains, or advanced IC engines could qualify to meet ARB’s SULEV standard.
ARB’s revised ZEV program allows for additional flexibility to broaden the scope of vehicles that could qualify for meeting some portion of the ZEV requirement. Manufacturers would decide which mix of vehicles to use to meet the 10 percent ZEV requirement, with the exception that large volume manufacturers would have to meet at least 40 percent of the requirement using true ZEVs. The applicable ZEV allowance for each vehicle type would be determined based on a set of criteria designed to identify and reward ZEV-like characteristics in a variety of advanced-technology vehicles. In order for a vehicle to receive any ZEV allowance, a vehicle would need to satisfy the requirements for receiving the “baseline ZEV allowance.” To receive this allowance, the vehicles would need to meet SULEV standards and also satisfy both second-generation on-board diagnostics requirements and zero fuel evaporative emission requirements. Vehicles that meet these requirements would be granted a 0.2 ZEV allowance. An additional allowance up to 0.6 is provided for vehicles realizing zero emissions potential with an extended range. This allowance could apply to hybrid electric vehicles with battery-only driving capability or fuel-cell-powered vehicles with nil emissions.
In addition, vehicles that use fuels with very low fuel-cycle emissions can receive a further ZEV allowance up to 0.2. The fuel-cycle emissions associated with a particular fuel are the total emissions associated with the production, marketing, and distribution, in grams per unit fuel. The marginal NMOG emissions associated with the fuel use by the vehicle must be lower than or equal to 0.010 grams per mile. For the purpose of providing this allowance, fuel-cycle NOx emissions are not considered in the determination, since marginal NOx emissions for virtually all fuels are expected to be uniformly low.
Fuel-cycle NMOG emissions can be over 0.1 g/mi for conventional gasoline vehicles. Fuels with low fuel-cycle emissions and high fuel economy have the potential for meeting ARB’s ZEV requirements. This study includes refined estimates of emissions from fuel production and distribution processes and develops estimates for year 2010 fuel-cycle emissions to determine which fuels could qualify for a ZEV low fuel-cycle credit. The assumptions and uncertainties in fuel-cycle emissions were examined in order to identify uncertainties and expected ranges in emissions. Fuel economy for advanced vehicle technologies was also evaluated in order to determine gram per mile emissions. The results, which are presented in this report, can be used to evaluate whether qualifying vehicle technologies meet the low fuel-cycle emission allowance for meeting requirements of ARB’s partial ZEV allowance.
1.2 Project Objectives