I have replaced oe 205s with 225/50-17 on 2001 20th Ann. rims. & lowered it.Ride height is now 26 1/4F & 26 3/4R. Im wondering if 225/55-17s will fit. Their dia. is 26.7. Im tryin g to get more miles per tire,and just a little softer ride. Any knowledge with the 55 series tires is what i need. Their are oe on 2004 SL max but i havent been able to compare wheelwell measurments.

 

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

Put in your stock tire size and then you can play around with the new size to see how it will affect your speedometer.