https://www.siliconvalley.com/2024/06/23/nhtsa-finalizes-moderate-fuel-economy-standards-for-2027-2031/

On June 7th, the National Highway Traffic Safety Administration (NHTSA) announced finalized fuel economy standards that will govern the auto industry during model years 2027-2031. The NHTSA is an agency within the U.S. Department of Transportation tasked with administering the Corporate Average Fuel Economy (CAFE) standards, and the finalization of new regulations marks the end of a complex rulemaking process. The agency ultimately settled for moderate stringency increases that appear to be acceptable to auto manufacturers and are closely aligned with relaxed tailpipe emission standards finalized by the Environmental Protection Agency on March 20th.

The NHTSA has a statutory obligation to promote energy conservation by setting fuel economy standards at the maximum feasible level automakers can achieve in each model year. Under the finalized rules, light duty passenger cars will face fuel economy targets that increase annually by 2% from 2027 to 2031. Light duty trucks will have it a little easier, with annual 2% target increases commencing in 2029. The agency estimates that the new rules will increase the average fleetwide fuel economy requirement from 47.3 mpg in 2027 to 50.4 mpg in 2031. The fleetwide fuel economy requirement stood at 35.8 mpg in 2022. The agency considered five regulatory alternatives that varied significantly regarding stringency, along with a sixth “no action” alternative. Of the five alternatives requiring some level of fuel economy improvement, the one that was adopted was the least aggressive.