Senate Bill Would Align Conflicting EPA, NHTSA Rules

The U.S. Senate has proposed a bill that would eliminate conflicting federal rules about fuel economy and exhaust emissions.

The Environmental Protection Agency manages laws about greenhouse gas emissions, including carbon dioxide. The National Highway Traffic Safety Administration oversees the country’s fuel economy rules. The two areas are linked because CO2 emissions are directly related to fossil fuel consumption.

Carmakers say current statutory differences can put them in a position where their cars meet EPA emission standards but could be penalized for not achieving NHTSA’s corporate average fuel economy numbers (CAFE).

The Senate bill harmonizes differences between programs relating to credits that fleets can earn for surpassing each agency’s standards, Automotive News reports. The bill would remove limits in how many credits a carmaker can shift between its car and truck fleets. The measure also would enable carmakers to apply CAFE credits for as long as 11 years— just as they can do now for emission credits from EPA.

Finally, the proposed law would recognize the fuel-saving benefit of such features as aerodynamic shutters or engine stop-start systems when calculating a vehicle’s official fuel economy rating.