Tag: def

is def fluid required by law

is def fluid required by law插图

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Diesel Exhaust Fluid (DEF) is anemissions control liquid required by modern diesel engines. It is injected into the exhaust stream. DEF is never added to diesel fuel. It is a non-hazardous solution of 32.5% urea in 67.5% de-ionized water. DEF is clear and colorless, and looks exactly like water.

People also ask


  • What is Def fluid made of?

  • It was mandated to come into use beginning with 2010-manufactured engines. DEF is a clear, colorless, non-hazardous liquid looking exactly like water but that has a slight odor of ammonia. It is composed of urea and deionized water.

  • Is it safe to keep Def fluid in your car?

  • It is perfectly safe to keep a gallon or two of DEF in your vehicle however it is not advisable. DEF will start to decompose at 86 F. It is very easy to forget about the DEF sitting in the back of your truck and given an extended period of hot days the fluid can become unstable and decompose but at a very minimal rate.

  • Can you put Def in a diesel engine?

  • Nope! Never! The DEF never makes direct contact with the diesel fuel itself 鈥?it is only sprayed into the exhaust stream. In fact, if DEF were allowed to enter the diesel fuel tank, it would contaminate the engine fuel. If the engine was then turned on, you would likely do significant damage to your vehicle.

  • What is DEF (Diesel Exhaust Fluid)?

  • Since the DEF (Diesel Exhaust Fluid) is introduced in the exhaust, also called after-treatment technology, the manufacturer is free to build as much power as they want. The DEF is stored in a separate tank which is insulated and heated and is marked by a blue filler cap.