Okay I used the SCT on my Marauder and its great! The thing is I went from getting 17 mpg to 13mpg. The car is stock except for a panel K&N but my question is - Would an Intake and a full exhaust with the SCT counter lose of mileage? I would like to have the car get decent mileage, maybe even throw in some denso's to see if that helps. Maybe even one step further and throw in the Tornado!