mx5cartalk.com

Wow, that is great!
There's a simpler one on Miata.net that i've been using. It's quicker to load but isn't as good as the one you posted.

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

Yea, great site though they list the NC as having 4 x 100 pcd and not the correct 5 x 114pcd.

Too bad if you bought their tyre/wheel combo off the web and then found they don't fit.

Their page showing side by side comparisons is interesting though.

Also, have a read of this:

http://www.roadandtrack.com/article.asp ... le_id=4228