On the outside, Ecsta KU31 tyres feature Kumho's High Dispersion Silica tread compound (that broadens the tread rubber's temperature operating range) moulded into a directional tread design that features large, independent shoulder blocks, four straight circumferential grooves and three solid centre ribs to combine wet grip, responsive handling and high-speed stability. Rotation Wear Indicators (R.W.I.) are built into the Ecsta KU31 to let drivers know the time has come to rotate tyres to maintain more even wear and lower noise levels into the later stages of the tyre's life. On the inside, Ecsta KU31 tyres feature twin steel belts reinforced by a spiral-wrapped, jointless nylon cap ply to enhance ride quality while providing high-speed durability.