sure - run as much advance as possible without pinging will give you optimal performance and mileage - also good clean air filter, synthetic oils, good air pressure, properly adjusted brakes, clean fuel system, etc... I have ran 27+mpg highway and 22 city in a 1988 5.0FI GT w/ 3.55 gear (properly calibrated) on a regular basis with 200k+ miles and others I have read have gotten 30+ mpg on the highway.