In article ,
Paul wrote:
Thanks Dave, you set me thinking. The last time I changed some
wheels on a car, I went from 13" to 15" and it was the first time
since I had owned the car that the speedo reading tallied with my
satnav, previously the car was always showing about 4mph faster.

As my Megane speedo shows a similar difference, can I expect the
same result?

Be easy enough to work out if you can find out the rolling radius of the
various wheel tyre combinations.

--
*White with a hint of M42*

Dave Plowman London SW
To e-mail, change noise into sound.