Attorney General Bonta Urges Department of Energy to Update Calculations that Determine Compliance with Federal Fuel Economy Standards

Monday, February 28, 2022
Contact: (916) 210-6000,

OAKLAND – California Attorney General Rob Bonta today led a multistate coalition in urging the Department of Energy (DOE) to update its “petroleum equivalency factor,” which determines how electric vehicles are accounted for when calculating auto manufacturers’ average fleetwide fuel economy under the Corporate Average Fuel Economy (CAFE) program. Currently, the “petroleum equivalency factor” is based on inflated and outdated data from over two decades ago, making it easier for auto manufacturers to comply with CAFE standards without making important improvements to the fuel economy of their fleet. This is at odds with Congress' goals for both the fuel economy program and the petroleum-equivalent fuel economy value: to conserve energy and incentivize the growth of the electric vehicle market.

“While we’ve seen significant improvements in fuel economy in recent years, the fact is, auto manufacturers could – and should – be doing more,” said Attorney General Bonta. "The inflated and outdated 'petroleum equivalency factor' has reduced incentives for auto manufacturers to improve the efficiency of their fleet, with important consequences for consumers and the environment. And as gas prices continue to reach new heights, consumers are paying the price at the pump. I urge the Department of Energy to review and update the 'petroleum equivalency factor' – for the sake of our planet and our pocketbooks.”

Under the Energy Policy and Conservation Act, the National Highway Traffic Safety Administration (NHTSA) is required to set standards to improve fuel economy and reduce the energy consumption of passenger cars and light-duty trucks to the maximum extent feasible. Electric vehicles do not, however, use “fuel” as defined under statute, so they do not have a “fuel economy” value. Congress directed DOE to assign these vehicles a value for the purposes of calculating the average fuel economy of auto manufacturers’ respective fleets thereby incentivizing the development and production of these vehicles. Unfortunately, the “petroleum equivalency factor,” a key component of this calculation, is based on obsolete data from over two decades ago and significantly inflates the petroleum-equivalent fuel economy value of electric vehicles.

In today’s letter, the coalition encourages DOE to update the “petroleum equivalency factor” so that the petroleum-equivalent fuel economy of electric vehicles is set at an appropriate level to comport with congressional intent.

Attorney General Bonta has led multi-state and multi-city efforts to support rigorous and stringent fuel-economy standards. In October, the Attorney General led a coalition of 22 states, six cities, and the District of Columbia in supporting the NHTSA's proposal to increase the stringency of CAFE standards for model year 2024-2026 vehicles. The previous month, Attorney General Bonta and New York Attorney General Letitia James led a multistate coalition in urging NHTSA to restore penalties for automakers that failed to meet CAFE standards for model year 2019-2021 vehicles.  

Attorney General Bonta is joined by the attorneys general of Delaware, the District of Columbia, Hawaii, Illinois, Maine, Maryland, Michigan, Minnesota, Nevada, New York, Oregon, Pennsylvania, Rhode Island, and Vermont, as well as the cities of Los Angeles, New York, and Oakland, in filing the comment letter.

A copy of the letter can be found here.

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