Gas is $2.35 a gallon. Get your truck and enjoy it. Hauling my bike from Mid Ohio to Deals Gap costs: $87.48 at the worst.
Call us back when it's $4.90. Most of my cross country trips, fuel is a negligible cost. Less than food. Less than decent charter tours even. If you use your truck for local use, nothing will give good mileage. On the freeway is the only place where I spend money on fuel and can save a little on fuel. And it's pretty weak. Not the major issue Expo makes it out to be.
But with the 5.4L:
-don't fear the gear. 4.30's or better. RPM helps as much as it hurts.
-skinny small tires, don't you dare go over 34". (295/70 r17 for example)
-avoid mud terrains if you live where there is no mud.
-stay low. No lifts.
-stay light. Avoid the poser winch bumpers.
-aero. Do not remove the front lower plastic air dam thing. Let it drag on rocks, beat on it, use it as a feeler. If it drags, so will your axle. No lights over the cab.
-keep the engine fresh.
-lube your hubs and service your axles and xfer case often.
-stay off the gas pedal on flat accel, but don't let the 5.4 lug up hills. The 5.4L burns more fuel if you baby it up hills. Stomp on it! Get up to speed and keep her there. The 5.4 likes steady speeds and higher RPM's. No soccer mom driving.
-replace your brakes with loaded rebuilt Ford Raybestos calipers. Fords are known for dragging brakes around 100k. (often seen in other fullsizes though) Replace the pins as well. Even if you think your calipers are fine. I use loaded calipers for every brake job I do on Superdutys. Has been working really well. No more pad rotor slaps. Easy, easy, way to make a truck feel new again.
-fill the tires up. Yeah, I know it's stiff.
-check your ball joints and tie rods. Floppy steering hurts mileage. Toe out is the debil.
-crew cab long box. Because potato.