Aspects of the present invention are directed at securely calculating and storing odometer data associated with a vehicle. In accordance with one embodiment, a method is provided that checks the integrity of odometer data being received from a vehicle's engine. More specifically, the method includes receiving a first and second engine odometer values for an engine. Then, these odometer values are compared to determine whether data indicative of tampering was received. In this regard, if data indicative of tampering was received, aspects of the present invention adjust the official vehicle odometer value to account for the tampering.