Nankang CX668 Touring Radial Tire - 165/80R13 Four straight groove designed patterns enhance the hydroplaning efficiency and the maneuverability on wet road condition. Dual double grooves on the tire shoulder divert and balanced the force caused on the tire shoulder when driving thus preventing uneven wears. Thinner sipes on the shoulder reduce efficiently the noise generation. Small block pattern design helps to provide better comfort. Pitch pattern designed by computer-simulated calculation reduces the noise generation.