i am on my second 6. 7 in under six months. i love the truck but i hate not being able to build a go fast truck out of it. i hate the DPF system. i lemoned my first 6. 7 because i had so many problems with the DPF and the exhaust brake. they put two turbos on that truck, one was hand delivered by Cummins. both of them got crap fuel mileage, both the the trucks are totally different. but i again i love the one i have but i miss the 5. 9