The engine has a 6.0, bullet proofed engine. It has airbags in the back for towing, well maintained truck, engine is running strong and has a lot more life still with no mechanical problems. You don't have to worry about Def, this truck doesn't require it, it's just ready to go and it drives like a dream. the reason for selling it is I got a work truck and don't drive it, and it is just sitting.