Hi, I just bought HPD Black Spinout 20" x 8.0" rims and was wondering what size tires would work with the RX8, The dealer told me 225 x 35 x 20 & 235 x 30 x 20, does anyone have any experience or knowledge of other sizes that would work? Thansk, Dave.

 

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

Just put the old tires in and then new tires. Make sure the new tires are same overall height as the old and you will be fine.