Happy Camper- I have an 07 3500 drw Dodge with the 6.7 Cummings, the milage was a little off at first , I now have 20k miles and the milage is pretty close to my 05. I get between 17 and 19mpg on the highway empty and 11 to 13 when pulling the Bighorn. My oil change alert is running between 5k and 6k . The engine brake and tranny make this truck for superior to the 5.9. I have never had any alarms or lights, it is a good truck, dont let some websites like Turbo Desiel Reg. turn you off of the truck it is usually the same guys griping over and over.