DEF FAQ Page
DEF MYTH: DEF is toxic.
Nope. DEF is nontoxic, nonflammable, and nonhazardous. This nonpolluting fluid won’t harm humans, animals, equipment, or the environment when properly handled.
DEF MYTH: DEF is urine.
There is no cow, cat, bat, or pig urine in DEF. It’s a mixture of 67.5% deionized water and 32.5% urea that is synthetically derived from ammonia and carbon dioxide.
DEF MYTH: DEF lowers fuel mileage.
To the contrary, DEF has been shown to increase engine performance and fuel economy by about 5%, so keep your DEF tank filled!