Gas engine.... 18.2mpg, 17.7mpg, 15.2mpg for 400 mi.
The 18.2 and 17.7 were set at the same trip, descending from the highest point in Ohio. Couldn't believe when I saw that number on this truck.
The 15.2 was not set on a highway road trip, it was putting back and forth to work on rural roads. Not surprisingly, the 80mph interstate driving trips don't give as good of mileage as my 50-55mph commute.