Diesel Exhaust Fluid (DEF) is a non-flammable fluid consisting of 2/3 purified water and 1/3 ammonia-based urea. DEF is used with diesel engine exhaust systems to reduce the amount of smog produced. The technology allows truck manufacturers to cut down the unhealthy nitrogen oxide levelsÃƒÂ³making more power and torque than ever before, while reducing engine wear and maintenance. Diesel Exhaust Fluid is sprayed into the exhaust stream to break down the generated NOx into harmless nitrogen and water vapor.
DEF is used with diesel engine exhaust systems to reduce the amount of smog produced.