EPA Proposes Ending Diesel Limp Mode for 2027 Trucks, Targeting $12 Billion in Savings
Updated
Updated · The Autopian · Jul 10
EPA Proposes Ending Diesel Limp Mode for 2027 Trucks, Targeting $12 Billion in Savings
3 articles · Updated · The Autopian · Jul 10
Summary
$12 billion in projected savings anchors the EPA plan to scrap DEF-triggered derates and limp mode for newly manufactured highway trucks, farm equipment and other diesel engines starting with 2027 models.
Under the proposal, operators would get audible and visible alerts instead of forced slowdowns when DEF runs low or systems fail, though manufacturers could still impose derates if needed to prevent engine or aftertreatment damage.
$6,000 per new truck in estimated savings would come alongside rollbacks to parts of the 2023 emissions rule, including tougher durability timelines and some extended emissions warranty requirements, while EPA says nearly 90% of NOx reductions would remain.
A 45-day public comment period and public hearing come next as the agency argues DEF failures have stranded trucks, hurt productivity and raised safety concerns despite earlier guidance that only softened derates.