There are a lot of guys out there who are getting better than 20mpg in thier Cummins Dodges, but I'm not one of them . In fact I was told that I would get 20 when I bought the truck, but I have yet to do better than 16 with mixed town/hwy driving. Still not bad for a 7000 lb truck ! The difference in most cases is that the guys who are getting the great mileage have 3.55 diffs and not the 4.10 that you and I are running Brian. Also, the newer trucks have solid front axles and no hydraulic disconnects which causes more drag on the 4x4's. Many other things to consider once you get familiar with the Cummins elctronics and changes in programming that have occured over the last few years as well. Bottom line is, I'm just jealous that I'm not getting that mileage. Maybe if I stopped racing all those little Hondas with 4" exhausts my mileage would improve ....naaah!