Tier 3 motor vehicle emission and fuel standards (NPRM)

The U.S. EPA has proposed new vehicle emissions and fuel quality standards intended to reduce air pollution from motor vehicles. The proposed standards, which will be phased in from 2017 to 2025 (in parallel with recently approved GHG standards), would reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles and some heavy-duty vehicles. Once fully implemented, smog-forming volatile organic com-pounds and nitrogen oxides will be reduced by 80% from current levels, particulate matter by 70%. Fuel vapor emissions will be driven to near zero. The proposal includes reducing current commercial gasoline sulfur levels from 30 ppm average to 10 ppm average across the nation by 2017. Changes to the fuel used for certification are also proposed, reflecting the widespread adoption of ethanol blends in commercial gasoline.

The EPA estimates that the fuel quality changes proposed by the Tier 3 program would cost about one cent per gallon of gasoline, and vehicle technology changes would cost about $130 per vehicle. As with previous vehicle and fuel emission standards, estimated annual benefits would far outweigh the cost; the benefits in 2030 would be three to eight times the cost of compliance, while helping the states to attain and maintain the existing health-based national Ambient Air Quality standards (NAAQs).

The Tier 3 proposal is almost completely harmonized with the California Air resources Board Low Emission Vehicle program (LEV III). This allows automakers to sell the same vehicles in all 50 states. The LEV III program starts in 2015 and has a phase-in period until 2025.

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