I have an 1988 Convertible and now have a set of Ronal 15" rims. Went to mount and they would not fit, rubbing on the inside. They are 15 X 7. I took a measurement as to the off set and came up with 38mm, does that sound right. I am not sure as how to space this rim so it does not rub, and I can use them. Will think about tire size after I solve this problem. Any help is greatly appreciated.