I bet with the 5.0 and 33's, you'd be at 18-19MPG on the freeway (at 70mph). My truck (with 33's) is at 21-22MPG, all freeway, at 70MPH. I was up in Wyoming a little while ago and on a 50 mile flattish section of the highway, no cars on the road (around 11PM), I was doing about 55mph and fuel...