Hi there,

Just wondering what's the correct widen tyre/rim size in order to get a correct speedo reading.

The tyres I have a the moment are 165/65 15R.

Thanks,
Ron

Found asnwers to my own question! :P

http://www.tyresave.co.uk/tyresize.html 
http://www.miata.net/garage/tirecalc.html