The US Department of Energy (DOE) has proposed a reduction in mileage ratings for electric vehicles (EVs) to meet the government’s fuel economy requirements. The move could force automakers to sell more low-emissions cars or improve conventional models. The proposed regulation would significantly revise how the petroleum-equivalent fuel economy rating for electric and plug-in electric hybrids is calculated for use in the National Highway Traffic Safety Administration’s Corporate Average Fuel Economy (CAFE) program. The current system has not been updated for more than two decades.
The DOE argues that encouraging the adoption of EVs can reduce petroleum consumption, but giving too much credit for that adoption can lead to increased net petroleum use because it enables lower fuel economy among conventional vehicles, which represent the majority of vehicles sold. Miles per Gallon equivalent (MPGe) ratings are determined by using values for national electricity, petroleum generation and distribution efficiency, and driving patterns.
Environmental groups have noted that fuel economy ratings for EVs are far higher for determining CAFE compliance than those listed on the government’s consumer fueleconomy.gov website. The Alliance for Automotive Innovation, which represents major automakers, warned last year that lowering the values could have far-reaching implications and would discourage EV adoption. The group said on Monday it was unclear how the proposed DOE calculation would be incorporated in future CAFE standards.
Under the DOE proposal, a Volkswagen ID.4 EV with a current 380.6 MPGe under CAFE would get 107.4 MPGe, while a Ford F-150 EV drops from 237.1 to 67.1 MPGe and Chrysler Pacifica plug-in hybrid falls from 88.2 to 59.5 MPGe. The Natural Resources Defense Council and Sierra Club petitioned for the change in 2021, arguing that “excessively high imputed fuel economy values for EVs means that a relatively small number of EVs will mathematically guarantee compliance without meaningful improvements in the real-world average fuel economy of automakers’ overall fleets.” Tesla backed the environmental groups’ petition.
The Environmental Protection Agency is expected to propose new rules on Wednesday to spur sweeping cuts in vehicle emissions that will push automakers towards a big increase in electric vehicle sales. The 2027 to 2032 model year pollution cuts are expected to result in at least half of the new US vehicle fleet by 2030 being electric or plug-in hybrids, in line with a goal President Joe Biden outlined in 2021. NHTSA is expected to propose parallel new stringent CAFE requirements soon. In 2022, NHTSA sharply boosted CAFE standards for vehicles, reversing former President Donald Trump’s rollback. Automakers buy credits or pay fines if they cannot meet CAFE requirements.
