Diesel Exhaust Fluid (DEF)
Diesel Exhaust Fluid (DEF) is a non-toxic solution used in modern diesel vehicles equipped with Selective Catalytic Reduction (SCR) systems. DEF is injected into the exhaust stream to reduce harmful nitrogen oxide (NOx) emissions, helping diesel engines meet environmental and emissions standards.
DEF is not a fuel additive and must never be added to the diesel fuel tank. It is stored in a separate DEF tank and is automatically used by the vehicle during operation. When DEF levels are low, warning indicators will appear on the dashboard. Operating a vehicle without DEF can result in reduced engine performance or speed limitations.
Proper DEF levels are essential to maintain vehicle functionality, emissions compliance, and safe operation of diesel-powered ambulances and support vehicles.