[quote author=aichdee link=topic=138445.msg2994579#msg2994579 date=1237072930]
Everything I have seen from other Miata forums and looking up stock size on tirerack etc.. shows 205/45/17 as the mx-5 stock size.
I think I might just end up going with this size because of the clearance tirerack has for the Bridgestone Potenza RE-01R
[/quote]
That may be the stock size for a Miata, but you don't drive a Miata "Profile says mazda 3" Just because you are putting Miata rims on a Mazda 3 doesn't mean that you want there tire size. The 205/50/17 is the tire you want, if you want the stock size tire for the Mazda 3. If you want a 45 side wall then go with 215/45/17
hope that helps.