U.S. CAFE Rule Projects a 34.9-Mpg Fleet Average for 2031

A revised U.S. fuel-economy rule projects a 34.9-mpg combined fleet average for 2031, potentially giving automakers more room to prioritize pickups and V-8 options in future vehicle lineups.

The final rule from the National Highway Traffic Safety Administration (NHTSA) covers Corporate Average Fuel Economy (CAFE) standards. It projects a 34.9-mpg average for passenger cars and light trucks in model year 2031. Its comparison case, which assumes the 2024 standards remain in place, puts the combined average at 49.3 mpg. These are fleetwide projections, not mileage floors that every vehicle must individually reach. The revision was announced Sept. 28 and published Sept. 30.

CAFE targets vary with vehicle footprint and whether a model is classified as a passenger car or light truck. For model year 2031, the rule projects averages of 40.2 mpg for passenger cars and 26.4 mpg for light trucks. Larger vehicles generally face less stringent targets than smaller ones.

TD Cowen auto analyst Itay Michaeli described one possible product response: “I could sell more V-8s and different trims of those pickup trucks.” Any shift in investment toward those vehicles remains unmeasured for individual automakers.

General Motors announced Sept. 17 that its 2027 Chevrolet Silverado 1500 and GMC Sierra 1500 would offer new 5.7-liter and 6.6-liter V-8 engines. That announcement came before the policy was announced Sept. 28, so it does not show that the rule prompted those engine plans.

A law that took effect July 4, 2025, set CAFE civil-penalty rates at $0 for model years in which the Transportation secretary had not already notified a manufacturer that a penalty was due. Credits generated in model year 2028 or later can no longer be traded across manufacturers. Credits earned through 2027 remain tradable and usable for up to five model years; transfers between fleets owned by the same manufacturer are still allowed.

For model year 2031, average vehicle technology costs could be $1,289 lower than in the no-action case if manufacturers make practicable efforts to comply. Gasoline consumption through 2050 is projected to be 4.6% higher than in that comparison.

The revision follows President Donald Trump’s earlier CAFE rollback announcement. The rule is scheduled to take effect Nov. 30.