I am lookin at these wheels and tires I don't have an exact size because they are used but I know they are a 20 inch rim he said the tape measure across the top of the tire was 9.5 inches the tires on my car stock measure just a hair over 8.5 will these rub on my car I have a 2006 grand prix, oh he said they are a 255-35-20 please help I'm new to this stuff thank you