Department of Energy Finalizes Major Update to Fuel-Economy Calculation

WASHINGTON, DC - Today, the Department of Energy (DOE) finalized a rule to update a two-decade-old calculation that determines the equivalent fuel economy of electric vehicles (EVs), phasing in important adjustments to the calculation. 

By overstating the miles per gallon equivalent of any EVs in automakers’ fleets, the prior calculation enabled automakers to continue to sell far more gas guzzlers. 

The Sierra Club and NRDC (Natural Resources Defense Council) petitioned the DOE in 2021 to update the calculation, which hasn’t been updated since 2000. The old calculation included a multiplier of nearly seven that significantly inflated the calculated fuel economy of electric vehicles. DOE’s final rule phases out the multiplier while updating other data used in the calculation with more current figures. 

This DOE calculation is used by the Department of Transportation in determining compliance with its Corporate Average Fuel Economy standards. It is wholly separate and has no impact on compliance with the vehicle emissions standards that are expected from the Environmental Protection Agency this week. 

“We appreciate that the Department of Energy is updating its old flawed and outdated calculation,” said Joshua Berman, senior attorney with the Sierra Club. “The prior calculation discouraged both widespread electric vehicle investments and improvements to the fuel economy of gas-power vehicles. Our communities will benefit from improving the accuracy of this fuel-economy calculation.” 

“The automakers’ free ride is over,” said Pete Huffman, senior attorney at NRDC. "This important update from the Department of Energy will curtail automakers’ use of phantom credits they used to keep selling gas guzzlers. They now need to hit the accelerator on more fuel-efficient vehicles, saving consumers money at the pump.”