Gearing-gearing;Don't trade away that set of 16's!!Swapping from 235/75R-15's to 235/85R-16's will improve your gearing noticeably.
Driving with my tailgate down CONSISTENTLY gives me 2 to 3 miles per gallon improvement.
A small 4 barrel,properly jetted,is worth some more savings.
Make sure you don't have a wheel brake or your e. brake dragging.
Keep your trucks alignment correct.
Keep your u-joints properly lubed.
A cruise control will help your mileage on the highway.
Synthetic lube in the transmission and rear end is a good thing.
I guess,if you wanted to really get into this,a lighter flywheel and smaller diameter clutch would take less horsepower to spin,but that's getting deep into the nit-picky details.
Speed
