My 06 has 3300 on it now and averages 19 on my 55mph country roads of I keep it to 60ish and don't rocket off each stop (very hard to do). The week after I got it I drove it from Charleston to St. Louis and back (1700 miles) and it averaged 19. 5, it had about 600 miles on it when I left. I kept it to the speed limit, since it was very new and it was amazing on the hills. The trip computer is about 1mpg higher than hand calculating it if there is allot of stop and go driving. I definitely see a strong connection between how I drive and the fuel economy. Towing my 3000 pound trailers drops it a few mpg and thats about it. I haven't towed the car hauler yet, we'll see, my 94 Chevy 5. 7 got 9 with it, I know this one will be better and an easier tow. So far I am very pleased with this truck, and can't stop grinning.