Originally Posted by
TMOliver
The "Odometer" is no more accurate than the speedometer, since they function using the same input, a mechanical "counter" of wheel revolutions. Changing your car's wheels to a different size, or even mounting tires of different size/specs will change the speedometer's and the odometer's readouts, both of which are set for the tires/wheels with which the car was originally equipped.
That's what one would think. However, my 2000 Jetta always displays the speed as high (70mph when the GPS says 67), however it is dead-on accurate (0.1 mile difference over a 600+ mile tank of fuel, e.g.) when registering miles on the odometer. I have no idea why that is, except that the speed needle isn't precise.
JP