Well Armour...maybe taking off the spare would lighten your load a little and like the other posts...go all synthetics and change the exhaust to dual and let it breathe better and also a cold air kit won't hurt either. I have an '02 S/C 5 speed and did my exhaust and cold air and went from 270 miles per tank to 330 on a trip to massachusetts, I know it was all highway mileage but hey mileage is mileage.