Okay, this thread will be dedicated to answering all questions E30-related about wheel sizing, geometry, and the accompanying tires. Of course this is to be used only as a rough guide, maXbimmer holds no responsibilty if you cram a tire into a fender.
To start, here are very informative Tirerack links explaining common terms:
For tire sizing, RWD E30s used two different rolling diameters, 195/60/14 and 195/65/14. The larger 195/65 was used on plastic bumper cars, but that diameter will fit just fine on all models, and provide a more accurate speedometer (they all read quite high stock). Notice I say diameter, meaning that for all upgrade purposes compare the new tire size with 195/65/14. All of the 325iX models used 205/55/15 tires. To calculate accurate upgrade sizes, look at this link:
Miata.net Tire Size Calculator
Factory wheel specs:
14" Bottlecaps: 14x6", ET33 (all non-iS non-iX cars, basically)
14" Basketweaves: 14x6.5", ET30 (all iS cars and some eS cars)
15" Basketweaves (iX): 15x7", ET41 (all 325iX models)
15" Basketweaves (Euro-only): 15x7" ET24 (option on European cars)
Now, this thread is open to all questions regarding fitment
of wheels/tires. Discussion of "what tire should I buy?" or "what colour should I spray paint my 18 year old bottlecaps" will be deleted or otherwise moved from the thread. Fitment questions only
. Note: answers may include tire recommendations in that particular size, but please no direct questions regarding tire choice.