What is the Purpose of Diesel Exhaust Fluid in Diesel Engines?
The primary purpose of Diesel Exhaust Fluid (DEF) in diesel engines is to break down toxic nitrogen oxide (NOx) emissions into harmless nitrogen gas and water vapor. Injected directly into the hot exhaust stream of vehicles equipped with Selective Catalytic Reduction (SCR) systems, DEF triggers a chemical reaction that enables modern diesel trucks to satisfy strict federal clean air standards without compromising engine power or fuel efficiency.