DEF (Diesel Exhaust Fluid)
DEF is a urea-water solution (32.5% urea, 67.5% deionized water) injected into the exhaust stream of diesel engines equipped with SCR (Selective Catalytic Reduction) systems. It converts NOx emissions...
Grant Taylor
Fleet Solutions Director, Fuel Ox
What Is DEF?
DEF is a urea-water solution (32.5% urea, 67.5% deionized water) injected into the exhaust stream of diesel engines equipped with SCR (Selective Catalytic Reduction) systems. It converts NOx emissions into harmless nitrogen and water. DEF consumption is separate from fuel additives — fuel additives go in the fuel tank, DEF goes in a separate tank. However, cleaner combustion from fuel additives can reduce the workload on SCR systems.
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