The Potenza RE070R R2 RFT is Bridgestone's Extreme Performance Summer run-flat tire developed exclusively for the all-wheel drive Nissan GT-R super sports car. In addition to combining athletic capabilities on the street with extreme dry performance on the race track, the Potenza RE070R R2 RFT also provides temporary extended mobility for a distance of 50 miles at up to 50 mph even after a puncture has allowed complete air pressure loss. However, like all Extreme Performance Summer tires, these tires are not intended to be serviced, stored nor driven in near- and below-freezing temperatures, through snow or on ice.The Potenza RE070R R2 RFT uses a revised asymmetric tread design that features wider, lower void outboard shoulders derived from the tires delivered as Original Equipment on the Nissan GT-R SpecV in Japan. Semi-Slick outboard shoulder blocks and several continuous inboard ribs enhance initial responsiveness and increase lateral stiffness to reduce the irregular wear that can occur during hard cornering.The tire's internal structure includes twin steel belts reinforced by spirally wrapped nylon to blend high-speed durability with uniform ride quality. The structure of the Potenza RE070R R2 RFT has been specifically tuned for the Nissan GT-R and features Bridgestone Side Support Run-Flat technology reinforced sidewalls to support the vehicle after a puncture causes a loss of air pressure.NOTE: The tread design change prohibits mixing the new tire with earlier non-R2 tires.While introduced as an Original Equipment tire on the 2011 model year Nissan GT-R, installing Potenza RE070R R2 RFT tires in sets of four is permitted on earlier Nissan GT-R cars.