Michelin XAS FF 145R13 Tire: STABILITY & SPECIAL COMPOUND "FORMULA FRANCE". Formula France "FF" tires have a slightly stiffer sidewall than the regular XAS. H Speed Rating H Speed Rated: Up to 130 mph (210 km/h). Often required OE for higher performance trim level classic automobiles. Michelin XAS-FF tire Stability & road holding when cornering. The "FF" (Formula France) is a tread mix which has been developed for racing use: circuit, rally and hill climbing. Thanks to an asymmetrical sculpture and its highly efficient special "Formula France" tread mix, this tire provides optimal adherence for track and rally use. Michelin Brand Collector Vehicle Tires Michelin is known for its high quality tires, and we keep thousands of popular Michelin tires in stock every day. Our Michelin product offerings include fitments from the 1920's all the way into the 2000's, with an intense focus on classic sports cars. Build quality, fitment options and period correct styling makes the Michelin product line a favorite among sports car enthusiasts around the world. 145R13 Tire Conversion Chart Similar Size Radial Alternative: 145/80R13