Diesel Exhaust Fluid

CountryMark supplies only API-certified UltraPure Diesel Exhaust Fluid (DEF). Here are some frequently asked questions regarding the use of DEF.

What is DEF and how is it used?Diesel Exhaust Fluid (DEF) is an automotive grade of 32.5% urea mixed with 67.5% demineralized water. It’s non-hazardous, non-toxic and non-flammable. DEF is used in Selective Catalytic Reduction (SCR) systems to change dieselpowered bus, car and truck NOx emissions to nitrogen and water.

How often will I need DEF? DEF will be used at about 2% - 3% of your diesel fuel consumption. So, every time you use 100 gallons of diesel fuel you will need approximately 2 – 3 gallons of DEF.

Is DEF a fuel additive? No. There is a separate tank for the fluid. DEF should not be added to the fuel tank.

What are the benefits of using DEF? Diesel engines equipped with SCR using DEF not only meet the 2010 tailpipe standard, they also deliver a significant fuel economy benefit.

Does it matter what DEF brand I purchase? Yes, it does. UltraPure is an API-certified, ultrapure, formaldehyde-free DEF. It is manufactured by Brenntag, the largest North American producer of DEF. 

Who has selected UltraPure? UltraPure is the factory fill and dealership choice for Volvo Trucks North America, Mack Trucks, Daimler Trucks North America, Freightliner, Ford, GM, Chrysler and Hino, to name a few.

Can I purchase UltraPure? What size would you like? UltraPure is available in 1-gallon and 2.5 gallon bottles, 55 gallon drums, 275-gallon and 330-gallon totes, and bulk.