With new EPA guidance on diesel engine derates, truckers may have more time to address aftertreatment system faults. Yet maintenance pros warn delaying repairs could lead to more expensive damage ...

The EPA on Tuesday said new trucks won't derate due to DEF system faults nearly as quickly or severely, and announced plans to modify software on all existing trucks to extend the timing for derates.

Engine, Truck Manufacturers Support EPA Easing Derate of SCR Diesel Emissions Controls School Transportation News News ...