What is it with DEF?
Just what is the Diesel Exhaust Fluid (DEF) ? What does it do and why do I need it? This is my first diesel and I never heard of it.
Forum Discussion
- Moved from Forum Technical Support
- I bought my first diesel truck last year. It uses DEF. It's easy to find, and it is used for Selective Catalyst Reduction. That's a fancy term for pollution control. All diesels use it now, even new big rigs.
It's easy to find in most parts stores, truck stops, and even some gas stations. I get about 1100 miles per gallon of DEF. It costs me about $16.00 for 2.5 gallons at the local parts store. It's even less expensive at WalMart.
Here's a website that can give you some background:
SCR and DEF
