The AVID ENVigor ZPS (Zero Pressure System) is Yokohama's High Performance All-Season run-flat radial developed to meet the year-round driving needs of sports car, coupe and sedan drivers. With the ability to provide temporary extended mobility for a distance of up to 50 miles at 50 mph in the event a puncture allows complete air pressure loss, AVID ENVigor ZPS tires are designed to combine performance, comfort and treadlife along with year-round traction, even on light snow-covered roads.The AVID ENVigor ZPS radial's all-season silica tread compound is molded into an optimized contact patch featuring a five-rib directional pattern that blends performance with all-season traction. Linked shoulder blocks and a continuous tapered center rib increase tread rigidity to improve straight-line tracking and handling. Independent intermediate blocks, angled grooves and adaptive 3D sipes enhance wet traction, help resist hydroplaning and promote traction in light snow.The AVID ENVigor ZPS radial's internal structure features twin steel belts reinforced by jointless nylon belt covers and belt edge strips that are spirally wound to provide long-term integrity under demanding conditions while they reduce tire weight and promote more uniform ride quality. Two rayon cord body plies help provide predictable handling while Yokohama's ZPS sidewall reinforcement can temporarily support the vehicle's weight even after a puncture allows a complete loss of air pressure.NOTE: Yokohama's ZPS tires are only recommended for vehicles originally equipped with self-supporting run-flat tires and a tire pressure monitoring system.