....with regards to the 10% out rule on our speedometers. If the speed is approx. 10% out, then is the mileage 10% out, since the the signal for the odometer is likely to be the same one as the speedo right? So a car that has travelled 11k miles, could actually be infact a 10k miles car, no?! This in effect would have ruined my mpg figures I've been calculating for the last few years also, so anyone else got an opinion on this? Now where did I puy my medication?