- NHTSA finalized a rollback on September 28, setting a fleetwide average of 34.5 mpg for model year 2031.
- The 34.5 mpg target gives automakers room to keep building SUVs and pickups.
- NHTSA estimates the rollback cuts average new-vehicle costs by $930.
The Trump administration finalized a rollback of federal fuel economy standards on September 28, replacing a Biden-era target that automakers had called unreachable. NHTSA's new proposal sets a fleetwide average of 34.5 mpg for passenger cars and light trucks by model year 2031.
That compares with the 50.4-mpg standard the previous administration had scheduled for the same year. President Trump has described the change as ending an "EV mandate," even though the Biden rule never required automakers to sell electric vehicles outright.
Trump's CAFE Rollback Cuts The 2031 Target
The Corporate Average Fuel Economy program sets minimum efficiency requirements automakers must meet across their US model lineups, and Monday's announcement rewrites the trajectory for the rest of the decade. NHTSA's proposal, first detailed in December, becomes the administration's formal replacement for the Biden-era schedule.
Under that earlier schedule, the required efficiency gains ran 8 percent annually for model years 2024 and 2025, 10 percent for 2026, then 2 percent a year through 2031. The new rule scraps that steeper increase in favor of a flatter curve automakers had lobbied against for months.
Federal emissions regulations have also come under fire this year. The fuel economy rollback opens a second track in the administration's effort to relax vehicle rules, and automakers that planned around the stricter Biden targets now have to rebuild their compliance plans around looser requirements.
According to Reuters, NHTSA estimates the rollback would cut average new-vehicle costs by $930 compared with the Biden-era path. The agency's own projections show the softer standard would also burn through roughly 100 billion additional gallons of gasoline by 2050, adding $185 billion in fuel spending and raising carbon-dioxide emissions by about 5 percent.
34.5 MPG Versus Biden's 50.4-MPG Target
The 15.9-mpg gap between the two standards is the number that most directly affects shoppers. It is the difference between an automaker chasing hybrids and lighter platforms, and one that can keep selling truck-heavy lineups largely as they are.
Light trucks and three-row crossovers face separate, less demanding targets within the CAFE structure than passenger cars, so a lower fleet average gives automakers room to keep building the SUVs and pickups that dominate US sales charts. That is a relief for companies that had warned the Biden targets would force costly electrification timelines.
It is also a shift with consequences beyond the showroom. Lower fuel-economy requirements mean less pressure on automakers to keep using efficiency tech like automatic stop-start systems, some of which have already started disappearing from new models for other reasons.
The technical rule NHTSA published Monday still has to clear a public comment period before it is final, so the 34.5-mpg figure could shift before it locks in. Automakers building 2028 and 2029 model-year lineups are watching closely, since compliance planning for those vehicles is already underway.
Motor1's Take: California and a few states that adopt its rules will still require automakers to sell higher-efficiency or zero-emission models there. Automakers will likely keep different model mixes and pricing by state instead of rolling back EVs nationwide.
That will make EV demand, charging and resale stronger in some regions and weaker in others. Whether automakers adopt a dual strategy or a national plan will decide how fragmented the market becomes.
