I have the original ScanGauge that is about 12 years old. No GPS but the newer ScanGauge II might have a model with GPS. I still don't understand why the difference in mileage between the ScanGauge and the odometer being that the SG should be getting the same data as the odometer. My 2004 Chevy 3500 had about a 3% difference between the odometer and the SG. When I sold the Chevy a year ago the odometer showed 819,759 miles but in reality it had 844,352 miles. I didn't reveal the discrepancy to the buyer thinking he may have tried to shave some off my asking price.