Michelin XDX | XDX Tire These 13 inch tires feature Michelin's XDX tread pattern and V speed rating and are a fantastic tire choice for many popular European applications requiring a 13 inch radial tire. Michelin XDX tires shares genetics with the incredible XWX performance tires and both were original equipment on performance and super cars of the era. The premium XDX Tire is available in two 13 inch sizes and feature authentic Michelin Classic tread designs. By the end of the sixties, Germany and Italy were the leaders in the European motorway development program. They were also the top producers of cars which could reach very high speeds. The huge open roadways and lack of speed limits allowed drivers to take full advantage of the incredible performance of the automobiles of the day.