Yes but other than the suggestions from the others, you would have to sway from stock and spend some $$$ with a good free flowing exhaust and maybe an after market electronic fuel injection and ignition systems. With those three items together you could pick up as much as 4 to 6 more MPG. However the cost would be high about $3500 to $5000 to do all three.
Along with the increased MPG would come the benefits of more power and better drivability the extra power would allow the use of taller gearing where you could possibly find another couple MPG for another $400 $500 of course.
The first thing to do is to ensure that the base engine is in good condition, no loss of compression no carbon build up exc. Then ensure that it is in the best state of tune possible, plugs wires timing exc.
