'99 5.9/4WD/3.55s - 15 city/18 hwy @70mph/21-22 hwy @55mph

Friend has identical truck, 5.2/4WD/3.92s - 13 city - same highway mpg.

The torque of the 360 helps to get the truck moving a bit more efficiently. (they are heavy - ~5500# empty)