Developing compounds for improved wet grip requires an understanding of the mechanism and a knowledge of the contributions of and interactions between, the tire materials and the tire operating conditions. As a generalization, increasing the hysteretic loss of the tread compound improves the tire＇s wet grip performance. However, a good balance of other tire properties must be maintained leading to an apparently contradictory reqirement between wet skid and rolling resistance for which low hysteresis is required. These conflicting requirements can to some extent be resolved because the operating conditions of the tread rubber for wet grip differs to that for rolling resistance, the former occurring at lower temperatures and higher frequencies. Materials development has used this fact advantageously; polymers have been developed with tuned hysteretic loss as a function of temperature and with recent emphasis on the role of fillers a significant optimization of overall tire properties has been achieved.