A relationship between the observed energy losses for a tire that has reached a state of thermal equilibrium when operating at a constant speed, and the viscoelastic properties of the tire components has been formulated. The analysis was carried out by systematically varying tire components and operating parameters, using the Vibron Viscoelastometer and tire test wheel dynamometer. The investigation was carried out for 6.95–14 cross ply passenger tires. From the derived dependence of the tire energy losses on viscoelastic properties, the effect of changes in tire tread compound, ply rubber and tire cord on the tire energy losses can be predicted. This enables the design of a tire with the properties to meet desired service characteristics.