Our 02 4x4 excursion 7.3l gets 16-19mpg and 03 4x4 f250 6.0l gets 14-17mpg. Diesel was a $1.10 when we bought them. The 6.0l would get 20mpg hi way when it was new. Had an injector go bad at 70,000m got it back and power was terrible and mpg down to 15 on hi way. Took it back and they told me that they put the newest flash out that was fixing everyone else's 6.0l problems. Nice. I wasn't having any problems. Asked them to reflash to the old, they said no can do. So bought a programmer and its helped some but its still not the truck that I first had. 260,000 miles on both.
