A 100 mile trip is no where enough to check MPG's.
This weekend, 531 miles of that 480 at interstate speed, 21.3 total MPG. Thats a 2003 4.0 automatic 2wd with 3.73's. Mobile 1 oil, Valvoline synthetic tranny fluid and a K & N air filter with the cold air mod (Interesting fact, I routinly...