A tire includes: bead cores; a carcass; a bead filler that extends along an outer face of the carcass from the bead core toward a tire radial direction outer side; and side reinforcing rubber that is provided at a tire side portion, that extends in the tire radial direction along an inner face of the carcass, that decreases in thickness on progression toward the bead core side and toward a tread portion side, that has an end portion at the bead core side that overlaps with bead filler with the carcass sandwiched therebetween, and that has an elongation at break of 130% or above, wherein a thickness of the side reinforcing rubber at a midpoint between an end portion at the tire radial direction outer side of the bead filler running along the carcass, and the end portion is 40% to 80% of a maximum thickness.

A run-flat tire ensures run-flat durability with a reduced weight. A tire radial outermost carcass ply of two or more carcass plies has tire widthwise inner ends in a crown portion. A bead filler and side reinforcing rubber have an overlapping part in the tire width direction. In a cross section of the run-flat tire in the tire width direction in a state where the run-flat tire is attached to an applicable rim, filled to a specified internal pressure, and placed under no load, a thickness d1 of a sidewall portion at a midpoint in the tire radial direction between a maximum width position of the run-flat tire and a tire radial outermost position of a bead core is greater than a thickness d2 of the sidewall portion at a midpoint in the tire radial direction between the maximum width position of the run-flat tire and a tread edge.

A pneumatic tire has a designated vehicle inner/outer side orientation for when mounted on a vehicle, and includes: a reinforcing rubber layer disposed in sidewall portions on sides in a tire lateral direction, the reinforcing rubber layer having a crescent shaped meridian cross-section; wherein a radius of curvature with an arc joining intersections of straight lines and a tire external contour, and a radius of curvature with an arc joining intersections of the straight lines and a carcass layer have a relationship such that, on the vehicle outer side, a radius of curvature of the carcass layer is large with respect to a radius of curvature of the tire external contour, and on the vehicle inner side, a radius of curvature of the carcass layer is small with respect to a radius of curvature of the tire external contour.

A side reinforcing rubber layer includes a second rubber portion having a modulus constant between a boundary surface and a bead portion and larger than a first rubber portion arranged on a tread-portion-2 side. The boundary surface intersects outer and inner surfaces of the side reinforcing rubber layer at first and third points, respectively. The first and third points are arranged on the bead-portion side of second and fourth points, respectively, which are closest points to an outer end of a belt layer of the outer and inner surfaces, respectively. A distance between an inner end of the first rubber portion and the second point is larger than a distance between the second point and the first point.

In a side reinforced type run-flat tire, a relationship between a distance (Do) from a center position of a circumferential primary groove that is positioned outermost in the tire width direction in a vehicle outer side region to a tire equatorial plane and a rim width (Wr) is such that 0.20Do/Wr0.30, and a relationship between a distance (Di) from a center position of a circumferential primary groove that is positioned outermost in the tire width direction in a vehicle inner side region to the tire equatorial plane and the rim width (Wr) is such that 0.25Di/Wr0.35.

A pneumatic tire includes a reinforcing rubber layer disposed in the sidewall portions, the reinforcing rubber layer having a crescent-like meridian cross-section. When the tire is assembled on a regular rim and in an unloaded state with an internal pressure of 0 kPa, a radius of curvature (RP) is smaller than a radius of curvature (RO), an arc of the radius of curvature (RP) joining an intersection (Pa) of a carcass layer and a straight line (La), an intersection (Pb) of the carcass layer and a straight line (Lb), and an intersection (Pc) of the carcass layer and a straight line (Lc), and an arc of the radius of curvature (RO) joining an intersection (Oa) of the straight line (La) and a tire external contour, an intersection (Ob) of the straight line (Lb) and the tire external contour, and an intersection (Oc) of the straight line (Lc) and the tire external contour.

A tire includes a tread formed in a crown region of the tire and sidewall regions extending from the crown region to bead areas. The tire further includes a toroidal element extending across a crown region of the tire, and further extending along at least a portion of each sidewall region of the tire. The toroidal element has a central region located between inner and outer regions. The central region is more elastic than the inner and outer regions.

A run-flat tire 1 comprises a carcass 6, a pair of side reinforcing rubber layers 9, and a pair of sidewall rubber components 10. At a tire maximum-width position, a first side reinforcing rubber layer 9A disposed in the side of a first bead portion has a thickness B1 greater than a thickness B2 of a second side reinforcing rubber layer disposed in the side of a second bead portion, and a first sidewall rubber component disposed in the side of the first bead portion has a thickness A1 smaller than a thickness A2 of a second sidewall rubber component disposed in the side of the second bead portion.

A pneumatic tire includes a run-flat reinforcing layer disposed on an inner side in a width direction of a carcass layer, and a second filler disposed between a turned back portion of the carcass layer and a rim cushion rubber. Additionally, a point on a tire outer circumferential surface is defined, the point is located at a position corresponding to 150% of a rim flange height from a measurement point of a rim diameter of a specified rim, a perpendicular line is defined, and the perpendicular line is drawn from the point to a tire inner circumferential surface. A rubber gauge (G1) of the run-flat reinforcing layer on the perpendicular line, and a rubber gauge (G2) of a region from the turned back portion of the carcass layer to a tire outer surface have the relationship 0<G1/G20.65.

In a tire 2, each load support layer 22 extends from a side portion 24 of the tire 2 to a radially inner side of a belt 14 at an inner side of a carcass 12. A ratio (SP/WB) of a width SP from an equator plane to an outer edge 48 of the load support layer 22, relative to a width WB from the equator plane to an edge of the belt 14, in an axial direction is equal to or greater than 0.1 and equal to or less than 0.6.