k&n air filter, hi-flow cat-back exhaust, hi-flow cats,power programers or chips, upper intake spacers,most of all stay ontop of tune ups and servicing. i've found that almost anything that makes more horsepower[ within reason] can inprove your fuel mileage. Have you ever heard of a Motorvac machine? HUGE fuel savings...goto-www.motorvac.com for more info. one tech i know offered your money back if you didn't find big fuel savings. he never had to give back one red cent.