EPA Weighs Dropping DEF-Derate Rules for Diesel Trucks

The EPA is considering eliminating limp-mode/derate restrictions triggered by low Diesel Exhaust Fluid in diesel trucks and is requesting data from the top manufacturers to assess warranty claims, failure rates, and repairs for certain model years, with a 30-day deadline. This follows a broader shift toward deregulation under Administrator Lee Zeldin, who previously extended the window before derates took full effect. If derates may no longer be required for compliance, diesel pickups could run at higher performance without frequent DEF refills.