Diesel exhaust fluid (DEF) is sprayed into the exhaust stream of diesel vehicles to reduce emissions by treating exhaust gases after they have left the engine.
DEF makeup and purpose
DEF is a non-hazardous solution made up of purified water and urea. It is not a fuel additive. Colorless and similar to baking soda in its alkalinity (pH), DEF breaks down nitrogen oxides in the exhaust stream in order to meet emissions control standards. This technology is called Selective Catalytic Reduction (SCR) and is used in select models of Tier 4 equipment to meet applicable standards.
Tips for use and storage
Fluid level indicators