The Trump administration is preparing to relax federal fuel economy rules in a move it says will make new cars cheaper to build — but whether that saving ever reaches the showroom floor is left entirely to automakers. Transportation Secretary Sean Duffy said Monday that Washington will soon announce significantly lower Corporate Average Fuel Economy standards, a regulatory reset aimed at giving Detroit more freedom in what it produces.
«We are about to announce a common-sense fuel economy standard because we want Detroit to build cars that Americans want to buy — not cars that Democrats want Washington to build,» Duffy said. The final numbers are not yet public, but according to Reuters, automakers expect something close to the National Highway Traffic Safety Administration’s December proposal, which would target a fleetwide average of roughly 34.5 mpg by 2031. That sits dramatically below the approximately 50.4 mpg expected under Biden-era rules.
NHTSA estimated its proposal could reduce new-vehicle costs by about $930 apiece, a meaningful figure at a time when affordability is one of the industry’s biggest problems. But lower manufacturing costs do not automatically translate into lower sticker prices. Automakers could pass those savings to consumers, pocket some as additional margin, spend the money elsewhere, or use their newfound regulatory breathing room to sell more profitable, less-efficient vehicles. CAFE regulates manufacturers’ fleets, not the price of individual cars.
There could be a less obvious benefit to the lower standards. Tougher efficiency requirements have encouraged manufacturers to employ technologies including friction reduction, low-viscosity lubricants, cylinder deactivation, downsized turbocharged engines and increasingly complicated transmissions. Less pressure to chase every fraction of an mpg could give engineers more freedom to prioritise simplicity, cost and durability. That does not mean lower CAFE requirements will magically eliminate recalls, but they could reduce the incentive to add complexity purely for incremental efficiency gains.
Developing cars takes years, and much of what will appear in showrooms over the next few years is already well into development. The immediate benefit for automakers could therefore come from easier compliance, particularly because the proposal would retroactively lower requirements going back to the 2022 model year. Meaningful changes to vehicle engineering and cost, however, could take considerably longer to materialise.
By then, Washington could change its mind again. The next presidential election arrives in 2028, three years before these proposed standards reach their 2031 endpoint. If Democrats retake the White House, another administration could begin the lengthy rulemaking process of tightening CAFE standards once more. The industry is currently in the middle of a pendulum swing: automakers were pushing EVs, axing V8s and planning for far harder standards after Biden tightened rules that Trump had weakened in his first term, which themselves replaced Obama-era regulations.
For an industry that plans vehicles five or more years ahead, the political cycle can move faster than the product-development cycle. In that sense, the full impact of these new rules on the industry will not be known until several years from now.