The Trump administration on Friday moved to relax fuel efficiency standards for medium- and heavy-duty commercial trucks by challenging the federal government's authority to regulate individual vehicle engines. The Department of Transportation issued a new legal interpretation stating that the government lacks the authority to set these specific standards, signaling a shift away from requirements established during the Obama administration.
The previous administration had implemented standards that regulated both the entire vehicle and its specific engine. The move is part of a series of administration efforts to reduce federal regulations concerning vehicle fuel efficiency, climate, and pollution.
While the new interpretation does not formally wipe out the existing engine standards, the Transportation Department implied in a press release that it would not enforce them while a formal rule change is finalized. Jonathan Morrison, head of the National Highway Traffic Safety Administration (NHTSA), stated that "American innovators — not Big Government — know how best to design vehicle engines" and that the administration is "getting out of the way" to allow manufacturers to decide how they will meet fuel efficiency requirements.
The administration has not yet provided a specific date for when the formal rule to permanently remove the engine standards will be finalized. For now, the Department of Transportation has indicated a period of non-enforcement while the regulatory process moves forward. Manufacturers will continue to face whole-vehicle efficiency requirements as the new engine policy takes effect.