My odometer reads correctly also, but there are some variables with the indicated speed. The needle plugs onto a tiny shaft and the needle could be out of position. The conditon of the coiled spring could also cause faulty readings, among other factors I'm sure. To check my speedometer I use a stopwatch and drive 45 mph for 1 mile. If the speedometer is accurate, it will take 90 seconds. 92 seconds is 44 mph, etc.
