i constantly get 17 or 18 mpg. on a straight highway drive going up north i only got 22. unless you seriously sit down and tune the crap out of these cars then they just dont get great mileage once you mod them. mine is untuned by the way, im running a DHP 1.5 file with a few codes deleted.

there has to be something wrong in your car for you to be only getting low teens for mileage though. o2 sensor gone? fuel filter completely shot? gas leak?