A run-flat tire includes a side reinforcing rubber layer, a first bead filler on an inner side of a carcass turned-up portion in a width direction, and a second bead filler on an outer side of the carcass turned-up portion in the width direction. A first bead filler height is 30% or less of a tire cross-sectional height SH. A second bead filler height is 50% or greater of the height SH. A cross-sectional area of the second bead filler is from 150% to 400% of a cross-sectional area of the first bead filler. A relationship (0.16×SH×LI−1100)≤S.sub.ALL≤(0.16×SH×LI−800) is satisfied, where S.sub.ALL represents a sum of cross-sectional areas of the side reinforcing rubber layer and the first and second bead fillers, and LI represents a load index.

A run-flat tire includes reinforcing rubber in a sidewall, first bead filler rubber disposed toward the inside of a folded back portion of a carcass layer in a lateral direction, and second bead filler rubber disposed toward the outside of the folded back portion in the lateral direction. The reinforcing rubber has a thickness from a rim base line to a position within 38% to 68% of a tire cross-sectional height being from 90% to 100% of a maximum thickness of the reinforcing rubber. In a range from a position of a rim check line to a position being 38% of the tire cross-sectional height from the rim base line, a total thickness of the reinforcing rubber, the first bead filler rubber, and the second bead filler rubber is from 100% to 140% of the maximum thickness of the reinforcing rubber.

Of layers configuring a bead core of a pneumatic tire, the width W0 of one of the layers including the greatest number of rows, the width W1, W2 of other of the layers located respectively innermost and outermost in the radial direction satisfy W1>W2 and W2≤0.5×W0. The position of width W0 is inward in the radial direction of the center of the bead core. A carcass is folded and curved along the bead core and extends toward sidewalls where a folded back portion of the carcass contacts a body of the carcass. A rubber occupancy ratio in a closed region formed by the body and the folded back portion is 0.1% to 15%. The cross-sectional area S2 and hardness H2 of a filler outward of the carcass in the lateral direction, and the cross-sectional area S1 and the hardness H1 of the side reinforcing layer satisfy 0.12≤(S2×H2)/(S1×H1)≤0.50.

The run flat tire includes a tread portion in contact with a road surface, a tire side portion continuous to the tread portion and positioned inside in the radial direction of the tread portion, and a carcass forming a tire skeleton. The run flat tire is provided with a side reinforcing rubber in tire side portion. A carcass reinforcing belt formed by covering a circumferential direction cord extending along tire circumferential direction with a rubber material and a sheet-like reinforcing layer formed of a resin material are provided in layers on an inner side of the tire radial direction of the tread portion.

A run-flat tire includes a belt reinforcing layer outward of a belt layer in a tire radial direction and reinforcing rubber in sidewall portions. Where a center region is a region of a tread portion in which a center land portion corresponding to a land portion included in land portions in a tread portion and located closest to a tire equatorial plane is positioned, the belt reinforcing layer includes a center reinforcing portion in which more pieces of the belt reinforcing layer are layered at a position of the center region than at positions other than the position of the center region, and in the belt reinforcing layer, a width Wc of the center reinforcing portion in a tire lateral direction with respect to a thickness Gr of the side reinforcing rubber at a tire maximum width position is within a range of 0.5 Gr≤Wc≤2.0 Gr.

A run-flat tire includes: sipes formed in blocks; a belt reinforcing layer on an outer side in a radial direction of a belt layer; and a side reinforcing rubber in sidewall portions, wherein a density of the sipes in a center block is from 0.10 cords/mm or greater to 0.30 cords/mm or smaller, the belt reinforcing layer includes a center reinforcing portion in which more center reinforcing portions are stacked at a center region than at positions other than the center region, a width Wc of the center reinforcing portion is within 0.5 Gr≤Wc≤2.5 Gr with respect to a thickness Gr of the side reinforcing rubber at the tire maximum width position, and an average width of the width Wc of the center reinforcing portion is from 50% or greater to 90% or smaller of a width of the center block.

A pneumatic tire is provided. A bead filler is disposed on an outer circumferential side of each bead core in bead portions, a side reinforcing layer having a crescent-shaped cross-section is disposed on an inner side in a tire width direction of a carcass layer in a sidewall portion, and as physical properties of a rubber that constitutes the side reinforcing layer and a rubber that constitutes the bead filler, a modulus at 100% elongation is in a range from 8.4 MPa to 10.2 MPa, a tan δ at 60° C. is in a range from 0.04 to 0.08, and JIS hardness at 20° C. is in the range from 75 to 79.

A run-flat tire includes side reinforcing rubber between a carcass layer and an innerliner layer in sidewall portions, first bead filler rubber arranged inside folded back portions of the carcass layer, and second bead filler rubber arranged outward of the folded back portions of the carcass layer in a lateral direction and along the carcass layer. In a meridian cross-section, a radial-direction height of the first bead filler rubber is 15% or greater and 40% or less of a cross-sectional height, a radial-direction height of the second bead filler rubber is 35% or greater and 55% or less of the cross-sectional height, a linear distance from a radial-direction outer end to a radial-direction inner end of the second bead filler rubber is 20% or greater and 45% or less of the cross-sectional height, and the second bead filler rubber has a larger cross-sectional area than the first bead filler rubber.

A sulfur-crosslinked rubber mixture, in particular for vehicle tires, and a vehicle tire. The sulfur-crosslinked rubber mixture contains at least the following constituents: at least one diene rubber and 0.5 to 10.0 phr of at least one anti-reversion agent and 2.0 phr or more of at least one para-phenylenediamine and 2.0 phr or more of at least one dihydroquinoline
and wherein the network node spacing of the crosslinked rubber mixture is 4.5 to 10 nm.

A carcass layer of a run-flat tire includes a carcass cord formed by twisting together organic fibers, wherein a breaking elongation Eb of the carcass cord, an average thickness Gs of a sidewall between a tire maximum width position of the sidewall and a position separated from the tire maximum width position to the outer side in a tire radial direction by a length equivalent to 15% of a tire cross-section height, and an average thickness Gsh in a tread between a shoulder position where a straight line orthogonal to the carcass layer and passing through a maximum width belt layer maximum width position intersects a surface of the tread and a position separated from the shoulder position toward the inner side in the tire width direction by a length equivalent to 15% of a maximum width belt layer maximum width satisfy: Eb≥20%; Gsh≥10 mm; Gs≥9 mm; and 60%≥Eb.Math.Gsh/Gs≥18%.