Today is Thursday, September 3, 2015

What is DEF?

Download DEF Product Brochure

Where will DEF be used?

  • Light to heavy duty passenger trucks.
  • Commercial and private fleets.
  • Stationary power such as generators.
  • Off-highway diesel engines.
  • Construction Equipment.
  • Rail and marine applications.
  • Agricultural applications.

Why Is DEF Needed?

In 2000 and 2001, EPA published the Tier 2 Emission Standards for Light Duty and Heavy Duty Vehicles, mandating that on-highway diesel and gasoline vehicles meet new strict emission control standards beginning January 1, 2010. Effective that date, no new on-road vehicles can be sold without meeting the Tier 2 emission standard: 0.2 grams of nitrogen oxide (NOx) per brake horsepower-hour. Gasoline engines, unlike diesel engines, do not have any problem meeting the new standards. Many end-users, however, prefer diesel engines due to their improved fuel economy on a mile-per-gallon as well as a mile-per-dollar basis.  

Diesel Exhaust Fluid (DEF)

DEF is a clear, colorless, non-toxic, non-flammable, non-combustible liquid.  It is made up of 32.5% urea with the balance deionized water.  The fluid is injected into the exhaust in a process called Selective Catalytic Reduction (SCR).   

Selective Catalytic Reduction (SCR)
Selective Catalytic Reduction (SCR) is one of the most cost-effective and fuel-efficient diesel engine emissions control technologies.  The ability to reduce NOx emissions to near-zero levels while delivering a 3-5% diesel fuel savings distinguishes SCR as one of the only emissions control technologies that is as good for business as it is for the environment.


Will Use SCR: Daimler (Mercedes, Freightliner, Sterling, WesternStar), BMW, Ford, Volvo/Mack, MTU/Detroit Diesel, PACCAR (Kenworth, Peterbilt, DAF), Hyundai, Kia, Nissan

Will Not Use SCR: Navistar/International, John Deere, Caterpillar
Undecided: Honda, Toyota/Hino, GM, Chrysler, Cummins, VW, Isuzu.

How DEF Works

With a few exceptions, every truck manufacturer around the world will begin use of the exhaust after-treatment to reduce diesel exhaust emissions, especially NOx(nitrogen oxide).  SCR(selective catalytic reduction) is the most widely adopted due to its simplicity and effectiveness.  During the SCR process, the urea based fluid is injected into the exhaust system, and when combined with NOx, forms nitrogen and water vapor.  It is an efficient way to dispose of pollutants while turning harmful emissions into the clean air we can breathe.        

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