I have an 07' 2500 Cummins and I love it. I don't pull loads all the time but when I do, it's a loaded up horse trailer headed over the passes to the other side of the hills. It's hard to beat running Eisenhower and Vail at 70 mph with a fully loaded trailer. I have been told that if you delete the EGR and DPF that they are absolute beasts and get amazing fuel mileage, I wouldn't know personally .