What is Diesel Exhaust Fluid?

If you own or are looking to buy a diesel vehicle, you may have heard of the term “DEF”, or diesel exhaust fluid. DEF is a requirement on modern medium and heavy-duty diesel vehicles, but what does it do and why do you need it in your vehicle?

What is DEF?

Diesel exhaust fluid, better known as DEF or under the brand name AdBlue, is a mix of urea and deionized water. This mix of fluids turns nitrogen oxide into water, nitrogen, and a small amount of carbon dioxide. Nitrous oxide is a harmful chemical emitted from burning diesel, as diesel is a much less refined form of fuel compared to gasoline. Nitrogen oxide not only contributes to the greenhouse effect in the atmosphere, it also poses health risks to the repository system in humans and animals. 

DEF is stored in a separate tank and is injected into the exhaust system of diesel vehicles to help reduce harmful emissions. This is called a selective catalytic reduction system (SCR), as DEF is only added to the exhaust system as needed. 

Why do I need it?

DEF is not only just a good idea to have in your diesel vehicle, it’s a requirement. In 2010 the EPA released the Diesel Emission Reduction Act (DERA), which required all new diesel vehicles to feature an SCR system. 

SCR systems remove up to 90% of the pollutants from diesel exhaust vapors, meaning they significantly reduce the negative effects of nitrogen oxide in the area around them and the atmosphere.

What happens if I run out of diesel exhaust fluid?

If your vehicle runs out of diesel exhaust fluid, chances are you will not be able to start or drive the vehicle. If it happens while driving, your vehicle will either give you ample time to stop the vehicle or force you to drive in a “limp mode” (significant power reduction and speed limitations) until you can get it refilled. 

That might sound frightening, but your vehicle will most likely give you more than enough warning before it gets to this point. When you see a low DEF warning on your dash, you should refill it immediately to avoid allowing it to run critically low. 

How do I get DEF?

Diesel exhaust fluid is available at the majority of gas stations, auto parts stores, and larger department stores.

DEF will usually come in quantities of a few gallons and should last you a while. However, it’s important to ensure the fluid you are using is not expired, as DEF can lose its effectiveness after about a year of sitting. 

Diesel service and repair in Summerlin

If you’re in the Las Vegas area and looking for high-quality light diesel services and repair, the expert team at Red Rock Repair can take care of you! From diesel pickups like Dodge Cummins, Chevy Duramax, and Ford Powerstroke to passenger diesels like the TDI, our technicians have extensive experience working on a wide variety of diesel makes and models. Call or request an appointment online today!