UK-POLOS.NET - THE VW Polo Forum

hello everyone,
when you look at different sizes of wheels, the corresponding tyre sizes are such that the total radii increases as you increase the wheel size. my 14" wheels have 60 profile whereas 17" wheels have 40 profile. there's a difference of approx. 55mm in total radius, which will affect the tachometer and the counter. how do we deal with this, get the dealer to update the software?
thanks!

Halfway this page you can fill in tire size calculator including difference of rolling radius.

http://www.chris-longhurst.com/carbible ... bible.html

wow thanks, this site has everything about tyres! like i thought, there will be a difference of 5.7 cm in circumference if i upgrade to 17" wheels. is that a big problem for the speedo or shouldn't i worry about it?

im planning 18s with 215/35/18 tyres and i dont think u should b worrying! ceedubya had 225/40/18 on his 1.2 9n and he had no probs