What is the mileage? How old are the plug wires, distr. cap, rotor,
spark plugs, etc.? When was the last time you had the transmission
serviced? Do you check your tire pressure regularly? These are just
some of the things that can affect gas mileage. I believe that you can
get updaed Proms for worn (read high mileage) engines and that may help.
Sometimes it's the little things, even driving habits, that can affect
gas mileage the most.