I have a similar gremlin with my trike as it adds mileage to the odometer while sitting peacefully in the garage. It became a real challenge with the disfunctional fuel gauge by eliminating the 200 mile fill-up process so I invested in a GPS speedometer / odometer to keep track of things. Thankfully it reconciles to the mileage reported by ProTune when connecting to the ECU. Another bit of "quirkiness" that makes them so endearing.
