DEF is a key component in lowering pollutants emitted from diesel engines, helping to reduce harmful emissions. Long-haul truckers and diesel engine enthusiasts had to rethink their entire operations ...

The short answer to why Diesel Exhaust Fluid doesn't work in the cold: It freezes at 12 degrees Fahrenheit. Comprised primarily of deionized water and urea, DEF serves to help make large diesel ...

New guidance to engine manufacturers will reduce "derating," an automatic trigger forcing diesel engines to operate at a reduced capacity when the emissions system runs out of diesel exhaust fluid or ...