I've got 195/65/14s on my car and they fit fine, the MGB needs about 4" backspscing with the 6" rim, I did alot of testing for Superlite and built a extra cushion into the backspacing, becuase I know guys will go bigger on tires, others have went as big as 205s, I just don't recommend it, mainly because I have liabilty to deal with, I don't want to tell you to go with 205s and they rub.