I don't know about the width, the factory 16's are only 7 inches wide, but I have 265/75/16's which are 31.6 inches tall, but using the miata tire size calculator http://www.miata.net/garage/tirecalc.html , I don't get the width, but 11.5 sounds too big for the 7 inch rim.. I guess I'd have to go measure my width, but I don't know, but the height is cool with no mods.. as long as your using the stock rims, or rims with the stock offset...