yes i think that is what i was trying to say, the speedo would always read the same, regardless of wheel size, but then most cars do too, like for instance if you fit different size wheels and or tyres, some unlucky folk get caught on speed camaras after buying a second hand car simply because the tyres and wheels fitted are non std size and they didnt know (it happend to my brother

) so we need to remember this when filling in on line ratio calculators, they all ask for (including mine) for a rolling radius, for these calculators it only effects us when messing around with vtec crossover points.(think i will hide the rolling radius box on mine so it cant be adjusted).