always use synthetic oil (
royal purple or synergen are best). results are smoother ride, better gas mileage and longer intervals between oil changes (15,000 to 20,000 miles vs 3,000 with regular motor oil).
2) trash your present sparkplugs and use autolite racing sparkplugs, for the best spark on the market.
3) use a high, 1000 amp, sealed battery, like optima, or orbital, not diehards! (diehards are low amp, usually 300).
4) for better gas mileage, put 5 mothballs (make sure they are the ones that contain naphthlalene) per gallon of gas in your tank (be careful as naphthlalene is a toxic substance). this one sounds kind of screwy, but the guy swears that it works and you'll notice the improvement in gas mileage right away. you can also add one ounce of liquid wd40 per gallon to help mileage (either in conjunction with the mothballs or by itself).
use these tips at your own risk, although the auto guy swore by all of them (especially the synthetic oil).