[speedytang]

My car has 145k+ miles and has had a supercharger on it for 55k+ miles. Original '89 shortblock with ported E7 heads and it pushes 450+rwhp at 12psi and drive it daily from April-Oct. I drive 75 miles a day highway and get 22.6 mpg at 70mph and mixed driving on the weekends 21 mpg. I have not seen my mileage change at all from being supercharged but I still use 3.08 gears to keep it highway friendly.