Lots of interesting info coming out here, would tire pressure also affect the diameter, ie if pressure was low would it have the effect of a smaller tire. It wouldn't would it? it should still have the same circumference right? Its too late in the day for me to get my head around that one!

I think i'll hook up my gps and see how accurate my speedo and milage indicator are. It would have been useful to have done that before the mods though as a comparison.

Pete