Just found this, i thought it was quite good, so thought i'd share.

 

 

 

 

Rim width---Min tyre width---Ideal tyre width----Max tyre width

 

7.0 inches-----195 mm--------205 or 215 mm-----------225 mm

 

7.5 inches-----205 mm--------215 or 225 mm-----------235 mm

 

8.0 inches-----215 mm--------225 or 235 mm-----------245 mm

 

8.5 inches-----225 mm--------235 or 245 mm-----------255 mm

 

9,0 inches-----235 mm--------245 or 255 mm-----------265 mm

 

9.5 inches-----245 mm--------255 or 265 mm-----------275 mm

 

10.0 inches----255 mm--------265 or 275 mm-----------285 mm

 

10.5 inches----265 mm--------275 or 285 mm-----------295 mm

 

11.0 inches----275 mm--------285 or 295 mm-----------305 mm

 

11.5 inches----285 mm--------295 or 305 mm-----------315 mm

 

12.0 inches----295 mm--------305 or 315 mm-----------325 mm

 

12.5 inches----305 mm--------315 or 325 mm-----------335 mm

good find that :)

This is also a good site to use...

 

http://http://www.miata.net/garage/tirecalc.html

215/45/17 on a 9.5 is what i run at the rear lol

Useful find matey

 

Now saved as a word document on my desktop for future reference :thumbup1:

http://www.alloywheels.com/tyrecalc.asp

 

Here is a nice calculator to work out how tire size affects your speedo! Useful!