[cleanspeed1]

There is a guy on here that made some changes to his Mustang convertible and posted near 40 mpg ( I think, don't quote me ). And that is with an automatic transmission.

The thing you need to do now is a compression check and a leakdown test. You are getting the kind of mpg a 5.0 would get without the fun, and a stock 5.0 with the right gearing and driven easy can get mid 20s or better ( manual transmission ).

If the engine passes the tests, do a full tune up and don't forget the timing belt and O2 sensor. Put a fresh catalytic convertor on too, if it's clogged up, engine can't breathe.

After that, get an electronic gauge that is compatible with your electronics ( I believe the Ultragauge is compatible, or an MPGuino ) and learn to drive by that. Consider it a game on your commute and make it fun.