[elhigh]

You're right that drag rises faster than your speed, so keeping it slow and easy is a big step toward improving the mileage in your ride.

25-27, that's pretty good, esp. in a 4x4. Even out of 4-wheeler mode, all that extra driveline and the big chunky tires present a lot of drag to the wind.

If your truck is jacked at all - even factory raised - there's probably a lot of space in those rear wheelwells with nothing in it. Add skirts and close off those big air buckets.