The Ultrac Vorti R is Vredestein's Max Performance Summer tire focused on drivers of sports cars and high-performance sedans who want to maximize the performance of their street-driven vehicle. The Ultrac Vorti R is designed to excel in warm dry and wet conditions, so like all Max Performance Summer tires, it is not intended to be serviced, stored nor driven in near- and below-freezing temperatures, through snow or on ice. The asymmetric design of the Ultrac Vorti R is molded from a high-grip tread compound engineered for superior dry and wet traction. The edges of the circumferential grooves feature draft angles designed to enhance rubber-to-the-road contact while cornering for improved traction, and the increased stiffness in the low-void, outboard shoulder aids handling. The mold shape of the Ultrac Vorti R is designed to create an extra-wide contact patch with minimal deformation for even temperature distribution. Wide, lateral grooves help flow water to the circumferential channels to enhance hydroplaning resistance, and increased void ratio on the inboard shoulder aids wet handling and braking traction. Internal construction of the Ultrac Vorti R features a two-ply, rayon casing for strength and durability. Two nylon reinforcement plies provide high-speed capability, and the wide, steel belts feature application-specific tuning. Tire sizes intended for front axles utilize a lower belt angle, while rear tire sizes use a high belt angle to optimize the balance between grip and stability in high-horsepower vehicles. Note: Tires exposed to temperatures of 20 degrees F (-7 degrees C) or lower must be permitted to gradually return to temperatures of at least 40 degrees F (5 degrees C) for at least 24 hours before they are flexed in any manner, such as by adjusting inflation pressures, mounting them on wheels, or using them to support, roll or drive a vehicle. Flexing of the specialized rubber compounds used in Max Performance Summer tires during cold-weather use can result in irreversible compound cracking. While compound cracking is not a warrantable condition because it occurs as the result of improper use or storage, tires exhibiting compound cracking must be replaced.