that may be average mileage for the 3.8.
I don't have one in my fiero, but my wife as one in her Regal.
On average (keep in mind, this is a 4000 lb car) she gets about 15 mpg. But she does very little highway driving.
Its real fun to get on it, watch the boost rise, and the mileage fall. I can get the gauge to read 2 MPG. Braggin rights there!
Check the plugs, and see what color they are. You may have to go with a hotter plug, or regap the plug.
Do you know the mileage of the car the 3800 came out of?
[This message has been edited by 85FieroGT3.4 (edited 10-26-2007).]