Dunlop SP Winter Sport 4D DSST (Dunlop Self-Supporting Technology) RunOnFlat (ROF) Performance Winter / Snow tires were developed for sports cars, coupes and sedans that come from the factory equipped with low profile tires mounted on large diameter alloy wheels. Designed to offer temporary extended mobility in the event a puncture allows complete pressure loss and perform in cold winter temperatures, SP Winter Sport 4D DSST ROF tires provide traction on dry, wet, slushy and snow-covered roads.SP Winter Sport 4D DSST ROF tires utilize a motorsport derived silica-plus tread compound that delivers high levels of grip, particularly on wet roads and in low temperatures. This compound is molded into a directional tread design featuring long V-shaped grooves that help resist hydroplaning to maintain good traction on wet and slush-covered roads. Dunlop's 4D Sipe System combines their 3D sipe technology with transverse sipes to create independent micro-blocks that generate better footprint pressure distribution to enhance snow handling and cornering grip. The tire's structure includes twin steel belts reinforced by Dunlop's JointLess Band (JLB) of nylon to optimize the contact patch and minimize tire growth at high speeds. Dunlop DSST ROF tires incorporate special sidewall reinforcements that can temporarily support the weight of the vehicle even after sustaining air pressure losses that would render conventional tires unusable. Designed to be run on while flat for up to 50 miles at speeds up to 50 mph, Dunlop DSST ROF tires provide drivers temporary extended mobility and the opportunity to drive away from stormy weather and dangerous situations. NOTE: DSST tires are only recommended for vehicles originally equipped with self-supporting run-flat tires and a tire pressure monitoring system. Dunlop SP Winter Sport 4D DSST ROF winter / snow radials meet the industry's severe snow service requirements and are branded with the three-peak mountain snowflake (3PMSF) symbol.Install Dunlop SP Winter Sport 4D DSST RunOnFlat tires in sets of four only.Do not mix radial winter / snow tires with tires of other construction, size, ply rating or pattern type. Dunlop highly recommends fitment of four winter / snow tires of the same type and rating for optimum mud and snow traction as well as to maintain vehicle handling characteristics. 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.