My driving habits when trying to stretch my gas mileage- Keep whatever tires you have all aired up to specs, keep the air filter clean (I installed a K&N kit which added 2 or 3 mpg), do not use ethanol or ethanol blended gas, no jackrabbit starts, try and keep as constant a speed as you can....and when on the highway if I drive over 73 mph I see gas mileage drop quite a bit......60 mph seems to be about the best.....understanding where your vehicle gets the best mpg is good to know... The old theory of driving a pickup with the tailgate down to improve mpg is a myth-mythbusters proved that. Keeping your vehicle tuned and all the things you mentioned kept up also helps. I once owned a Dodge 1/2 ton shortbed with a 318 in it. It got 12 mpg, loaded, unloaded, fast or slow, didn't matter how I drove or what I did (as long as I kept it maintained up to snuff). Sometimes a vehicle is just going to suck gas.