Did you check the air pressure in the tires? If it's been in 4WD, that kills mileage. My kids 97 gets crappy mileage, probably 11 mpg in town. My 90, until I put the correct CPS in it(not available for 91 and up) got 10 mpg in town when it was stock, and it's a stick.
Might ask at NAXJA, you...