Winter Sottozero Serie II Run Flat tires are Pirelli's second generation of Sottozero Performance Winter / Snow run-flat tires developed for the drivers of premium, high performance vehicles facing challenging wintertime road conditions. Winter Sottozero Serie II Run Flat tires feature Pirelli's Self-Supporting Run Flat Technology that enhances safety and convenience by providing temporary extended mobility in the event a puncture allows complete loss of air pressure. Pirelli's Self-Supporting Run Flat Technology allows tires to literally "run flat" for up to 50 miles at 50 mph (80 km at 80 km/h) unless otherwise specified by the vehicle manufacturer for Original Equipment tires. The Winter Sottozero Serie II Run Flat was developed with the philosophy that winter / snow tires must perform in a variety of unpredictable weather conditions and aren't just for use in the snowbelt states. Winter Sottozero Serie II Run Flat tires are designed not just as winter / snow tires, but as seasonal tires suitable for the weather and road conditions typically experienced in parts of the U.S. between November and April by providing traction and handling in dry, wet, cold and wintry conditions. Winter Sottozero Serie II Run Flat tires use a tread compound featuring new polymers and mixing processes that allow them to be ecologically friendlier because they are free of aromatic oils. Pirelli's Temperature Dynamic Compound technology optimizes the compound for wet and icy surfaces to provide improved traction in winter's near-freezing and lower temperatures. The tread blocks feature Pirelli's Interactive Brickwork Siping where the sipes create a brickwork pattern that increases both lateral and longitudinal stability while providing more biting edges to increase snow traction, ride comfort and noise quality. The tire's internal structure includes twin steel belts reinforced by spirally wrapped polyamide that enhances thermal stability and makes the tires less sensitive to changes in road and air temperatures.Pirelli's extended mobility solution is made possible by their MIRS computer-controlled robotized manufacturing system, a production process that assures consistency in the application of the additional sidewall reinforcements that provide the self-supporting run-flat capability.Winter Sottozero Serie II Run Flat winter / snow tires meet the industry's severe snow service requirements and are branded with the three-peak mountain snowflake (3PMSF) symbol.Install Winter Sottozero Serie II Run Flat tires in sets of four only.Due to the traction capabilities of the Winter Sottozero Serie II Run Flat tires, Pirelli recommends using them only in sets of four to provide the best handling characteristics and tire performance.Though they cannot be labeled as run-flat tires, tires branded with MOExtended or MOE on their sidewalls offer run-flat-like characteristics by delivering limited temporary extended mobility after a puncture results in complete loss of air pressure. Because MOExtended or MOE tires do not have the same speed and distance endurance of conventional run-flat tires, they should not be substituted in any situation where a conventional run-flat tire is required. To confirm what your vehicle needs, check our Original Equipment tire listing for your year, make and model or see your vehicle owner's manual. Related Information: What is the three-peak mountain snowflake symbol (3PMSF)? | Learn more about MOExtended/MOE tires here.