Well, we just got back from a 15 day trek from sandy, oregon to Alexandria, Minnesota. The path out was through yellowstone, the northern route on the return trip. Average mpg was 14.25 all totaled, with some tanks as much as 20 and the worst at 10. I have only owned this unit for a month, and tried to do everything possible to get it ready, and it worked like a champ. The only issues that cropped up were an inability to stay in overdrive at 55mph in a headwind, and this crying noise it makes when hot and not under load. I think there is a water pump in my future, though it held temp very well, even over the numerous mountain passes. I would say the worst part is getting passed by trucks and big class a's going twenty mph faster than me. It feels like I am going to get pushed off the road!