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
The Chevy dealership told us we only need to replace when the info panel says to. We buy it at SAMs Club and try to keep a spare jug on hand (use a jug, buy a jug sort of thing). Our last two trucks have required it. Once we needed it when we were traveling and bought at a truck stop. It is much less expensive at SAMs. It is for emissions control.
