EPA Proposes Eliminating DEF Derates for MY2027 Heavy-Duty Diesels: What Fleet and Shop Buyers Should Know Before August 29
Source: FleetOwner / ILMA (Independent Lubricant Manufacturers Association), July 9, 2026 The EPA has formally proposed a rulemaking (Docket No. EPA-HQ-OAR-2026-0728) that would end mandatory engine-power and vehicle-speed derates triggered by diesel exhaust fluid (DEF) faults on model year 2027...
