I have a 1992 honda accord with a 130.000 miles on the car I get from 15 to 20 miles per gallon. I have changed the plugs wires and o2 sensor without any improvement in fuel economy.I drive with a light foot. I wonder if a valve adjustment would make a difference.

have you tried fuel injector cleaner? how bout the quality of gas? Some companies dilute their gas slightly. the air filter also might be a place to look. Just a couple of cheap suggestions.