Tonka, there HAD to be something wrong with your 6.0. If I ran mine at 57-63 empty I garuantee I would get 20+mpg with it. My 95 would easily get 12-14 loaded at those speeds. I havent towed with the 06 yet so I cannot comment. At 60 mph the 6.0 is barely turning 1700 rpm.
Anything quoted claims north of 25mpg in a 3/4 or 1 ton diesel is pure ********.
Anything quoted claims north of 25mpg in a 3/4 or 1 ton diesel is pure ********.