Superchips tuners plug directly into your vehicle and read the stock calibration stored in your vehicle. A stock calibration is the set of fuel, spark and transmission settings that the dealer installed in your vehicle at the time of sale. After reading this file and saving it to your Superchips tuner, the hand-held device then downloads the Superchips calibration to your vehicle. All engine and vehicle operations work exactly the same, except your engine will now work more efficiently - which equals more power, more torque and better mileage.