Trump’s Transportation Department Moves to Reverse Illegal Obama-Era Rule Unfairly Restricting American Engine Manufacturing Action will unleash innovators so they can design[...]

The U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) today moved to reverse an Obama-era rule regulating standalone medium- and heavy-duty truck engines. The rule - which went far beyond Congress' intent - restricted manufacturers' ability to design innovative approaches to meet commercial truck fuel efficiency standards. Under the Trump Administration, NHTSA is returning that authority to vehicle manufacturers who can best decide how to improve fuel efficiency.

Federal statute and court decisions make it clear that NHTSA's authority is limited to regulating the fuel efficiency of vehicles, not standalone engines or vehicle subcomponents. Today's interpretive rule aligns the agency's regulatory footprint with law.

"American innovators - not Big Government - know how best to design vehicle engines. The Trump Administration is getting out of the way so manufacturers can decide how they want to meet fuel efficiency requirements," said NHTSA Administrator Jonathan Morrison. "Ensuring the commercial truck fuel efficiency program complies with Federal law will also lower commercial truck prices and allow American manufacturers - and the thousands of hardworking people they employ - to thrive."

Highlights of the Rule

• Focus on Vehicles: The Energy Independence and Security Act explicitly directs NHTSA to establish a fuel efficiency program for commercial vehicles. Unlike the Clean Air Act - which gives the Environmental Protection Agency explicit authority to set emissions standards for engines - EISA contains no statutory authority for NHTSA to regulate engines or components like transmissions or tires.
• Alignment with Judicial Precedent: The interpretation applies the best reading of the law in light of the U.S. Supreme Court's Loper Bright Enterprises v. Raimondo decision, as well as a recent decision from the U.S. Court of Appeals for the D.C. Circuit that found the agency has no authority to regulate the fuel efficiency of non-vehicle components.
• Support for Market Flexibility: Regulating complete vehicles gives manufacturers greater flexibility to innovate and tailor designs to the real-world operational demands of commercial customers that could include improvements to the engine as well as other parts of the vehicle such as transmissions, cab design, and tires.

Next Steps and Enforcement

The interpretive rule does not itself change existing standards. It establishes the legal foundation for a forthcoming notice-and-comment rulemaking to officially reset the MDHD program.

Pending that rulemaking process, NHTSA will exercise its enforcement authority in alignment with this interpretation.