[elhigh]

I kinda chuckled to myself when I saw you mention hypermiling and tractors in the same sentence. Considering what they do, the loading regimes in which they spend all their operating time, I don't think there's anything you could do for the tractor.

I have a '45 Farmall A, it's really just a toy. But the governer built into the front end is what the throttle lever controls, really, so when I start to load up the engine, it's the governer that gooses the gas, not me - I don't move the lever. When the load goes down, the governer lightens up and gives exactly the right amount of fuel to keep the engine at the selected speed.

I'm not telling you anything you don't already know, I actually kind of surprised myself to have that all in my head. But my point is, those things are already scrimping wherever possible, just from the outset.

Is your F-150 4x4? If not, maybe you could lower it a fuzz, add an airdam to get the wind out from under the truck, smooth things up a bit? Make it easy to remove for when the snow flies. And check out Aerohead's stuff with aerodynamic caps. Certainly there must be some way to make an aero cap to cover the bed, that would be easy to remove or fold or something for when you've got the bed full.