Diesel Exhaust Fluid

What is DEF, why is it required in newer vehicles, and does it hurt vehicles?

In an attempt to the cut emissions, all 2008 and newer 3/4 ton and heavy diesel fueled vehicles must be equipped with DEF or Diesel Exhaust Fluid. DEF breaks up harmful NOx that is emitted from the diesel vehicles into harmless water and nitrogen. DEF is made up of 2/3 de-ionized water and 1/3 synthetic urea. The urea is regulated by the API (American Petroleum Institute).

The biggest concern that diesel vehicle enthusiasts had when DEF was first introduced was, whether or not power would be sacrificed in exchange for lower smog emissions. This is avoided as DEF isn't a fuel additive, being injected into the exhaust instead of being added to the fuel allows for manufacturers to unleash the full power of their engines. In fact through DEF and SCR (Selective Catalytic Reduction) manufacturers were able to get more power and torque out of their trucks!

DEF is an non-hazardous liquid that simply breaks NOx in water and nitrogen, two harmless materials.

Author:

Robert Stahelski

Domestic Fuels and Lubes, Ocean State Oil