| 摘要 |
PURPOSE:To improve the rolling resistance performance and wet grip performance of a high-fuel-efficiency tire including a toroidal radial cord carcass, by setting the base rubber and central and side cap rubber of the tire at prescribed loss elasticity module. CONSTITUTION:In a radial tire having a tread and a breaker layer outside the crown part of a carcass made of plies of radially-arranged cords toroidally secured on the bead, the circumferential volumes Va, Vc1, Vc2 of the base rubber (a) and central part c1 and side part c2 of the cap rubber (c) and the circumferential volume VT of the tread T are related to each other as formulae (II) and the loss elasticity module E''(a), E''(c1), E''(c2) of the rubber parts (a), c1, c2 are set within prescribed ranges indicated by other formulae (I). As a result, the rubber parts (a), (c1), (c2) are provided with different functions that the rolling resistance performance and wet grip performance of the tire are collectively improved. |
