Storm 2 Ultra. The Storm-ST range gives you more mileage and more grip. Multi-compound Super Rich Silica (SRS) treads gives rear tyres an extra 12% mileage. New technology is incorporated in the 0 degree belting system and dynamic stresses within the carcass have been tuned. This new technology not only increases mechanical grip, giving improved traction in both the wet and dry, but it also enhances handling and ride comfort.