The National Highway Traffic Safety Administration is moving to reset the federal fuel-economy path for model year 2031, replacing a Biden-era target of 50.4 mpg with a fleetwide average of 34.5 mpg for passenger cars and light trucks. Announced on September 28, the Trump administration’s rollback gives automakers more flexibility to continue selling SUVs and pickups, although the rule must still pass through a public comment period before the figure is locked in.

The change represents a 15.9-mpg gap between the scheduled target and NHTSA’s proposed replacement. It also marks a major shift in compliance planning for automakers developing 2028 and 2029 model-year vehicles, since those programs are already taking shape around expected federal requirements.

What the 34.5-mpg standard changes

The Corporate Average Fuel Economy program measures efficiency across an automaker’s U.S. lineup rather than applying one identical requirement to every vehicle. Light trucks and three-row crossovers have separate, less demanding targets than passenger cars, meaning a lower fleet average can give manufacturers more room to maintain truck-heavy product strategies.

The previous schedule called for efficiency gains of 8 percent annually for model years 2024 and 2025, followed by a 10 percent increase for 2026 and 2 percent annual gains through 2031. The replacement plan scraps that steeper trajectory for a flatter curve that automakers had opposed during the rulemaking process.

President Trump has characterized the rollback as ending an “EV mandate,” although the Biden-era fuel-economy rules did not directly require automakers to sell electric vehicles. The softer standard instead reduces the regulatory pressure to add hybrids, battery-electric models, lighter platforms and other efficiency technology across a national lineup.

Lower vehicle costs, higher fuel use

NHTSA estimates that the rollback would reduce the average cost of a new vehicle by $930 compared with the Biden-era path. That potential savings comes with higher projected fuel consumption over time. The agency estimates the looser standard would use roughly 100 billion additional gallons of gasoline by 2050, add $185 billion in fuel spending and increase carbon-dioxide emissions by about 5 percent.

The rule could also lessen the need for features such as automatic stop-start systems, some of which have already begun disappearing from new vehicles for other reasons. Automakers that invested in stricter compliance plans will now have to reassess their powertrain and product strategies.

State rules could keep EV plans divided

Federal changes will not necessarily produce one uniform strategy across the United States. California and states that adopt its vehicle rules will continue to require automakers to offer higher-efficiency or zero-emission vehicles. Manufacturers could respond with different model mixes and pricing by state, or maintain a nationwide EV and hybrid strategy despite the relaxed federal target.

For shoppers, that could mean regional differences in EV availability, charging demand and resale values. The 34.5-mpg figure remains subject to public comment, so its final form may change before it becomes binding.