Patent ID: 7918257

Claim:
A run-flat tire comprising: a pair of bead portions having an annular first bead; inner and outer sidewall portions on an inner and outer side of a vehicle on which the run-flat tire is adapted to be mounted, respectively, extending to an outer side in a tire diametrical direction from said bead portions; reinforce rubber layers arranged in said sidewall portions, said reinforce rubber layer in the inner side wall portion comprising one or more rubber layers, and said reinforce rubber layer on the outer side wall portion is constituted by a single layer; a tread portion connecting outer peripheral side ends of said sidewall portions via shoulder portions, wherein the run-flat tire comprises: an annular inflating portion provided on the outside in a tire width direction of said bead portion arranged only on the outer side of the vehicle, and having an inner circumferential side face opposing to an outer circumferential curved side face of a rim flange when a regular rim is fixed; and an annular second bead arranged at the annular inflating portion, wherein the single reinforce rubber layer arranged in the outer sidewall portion has a rubber hardness of 60 to 82 degree, the one or more rubber layers of the reinforce rubber layer arranged in the inner sidewall portion have an average rubber hardness of 65 to 90 degree, and the one or more rubber layers of the reinforce rubber layer arranged in the inner sidewall portion has an average rubber hardness which is equal to or more than that of the single reinforce rubber layer arranged in the outer sidewall portion, and has a maximum thickness of all of the rubber layers which is larger than that of the single reinforce rubber layer arranged in the outer sidewall portion by at least 0.5 mm, wherein a tread pattern formed in said tread portion is structured such that a void rate in the outer side of the vehicle is in a range of 75 to 100% of the void rate in the inner side of the tread portion on the boundary of a tire equator line, and wherein the reinforce rubber layer arranged in the sidewall portion which is on the inner side of the vehicle has a rubber hardness larger than that arranged in the sidewall portion which is on the outer side of the vehicle by at least 5 degree.