I heard a guy on the forum saying that his odometer was still off with a speedohealer. Don't see how, he may have a different version. The v4 connects between the speed sensor in the transmission and the computer so it would have to adjust the odometer. I am going to get out saturday with my gps and compare, not really striving for perfection because these bikes were off from the factory, but would like to be pretty close. Also have some duke maps for the pcIII. Found one that does pretty good on mine. If you don't have the file you can probably find it on the forum or i can send it to you saturday sometime.