Granatelli GranSpeedo™ Speedometer Calibrator

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Accurately calibrate today’s electronically controlled speedometers for 1994-current GM cars, trucks and SUVs *. Now there is a simple way to correct for unwanted speedometer error caused by wheel and tire changes, rear-end gear changes and even transmission slippage! GranSpeedo™ is a simple unique device designed to adjust odometer and speedometer settings in today’s most popular GM cars, trucks and SUVs. All too often, a simple gear change or a new tire and wheel package can knockout factory settings. The GranSpeedo™, unlike other systems that try to make changes to the hard settings within the factory ECM, is a “buffer box”. No changes are actually made to the factory settings within the computer, so going back to stock is simple and it won’t void the factory powertrain warranty. Accuracy is guaranteed to within 1/6000 of 1 mph. Each system includes everything you need to calibrate your speedometer except the computer. Installation takes about 15 minutes.
* Does not fit 1997-03 Corvette.