A tire comprising a tread portion, a pair of sidewall portions continuous on both sides of the tread portion, bead portions continuous on each sidewall portion, side reinforcing rubbers with crescent-like cross section disposed on the sidewall portions, a carcass formed of plies of radially arranged cords extending toroidally between the pair of bead portions, wherein: when the tire is mounted to a rim, and an internal pressure of 250 kPa or more is applied to the tire, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; and in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD ≥ 2.135 × SW + 282.3 mm; the bead portions have bead cores, and further have bead fillers on a tire radial outer side of the bead cores; wherein the folded-up end of the carcass folded-up portion is located on a tire radial side inner than the tire maximum width position, characterised in that: the tire is a run-flat tire; in that when H1 is a tire radial maximum length of the side reinforcing rubber in a tire widthwise cross section in a reference state where the tire is mounted to a rim and filled with a predetermined internal pressure with no load applied thereon, and H2 is a length of a straight line segment connecting a tire radial outermost point of the bead filler and a tire radial outermost point of the bead core, H1 and H2 satisfy 1.8 ≤ H 1 / H 2 ≤ 3.5; in that the 50% stretch modulus of the side reinforcing rubbers is 1.5 to 6.0 Mpa; in that a maximum thickness of the side reinforcing rubbers measured in a direction perpendicular to the carcass is 6 mm or less; and in that the tire has an air volume of 15000 cm 3. when the tire is mounted to a rim, and an internal pressure of 250 kPa or more is applied to the tire, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; and in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD ≥ 2.135 × SW + 282.3 mm; the bead portions have bead cores, and further have bead fillers on a tire radial outer side of the bead cores; wherein the folded-up end of the carcass folded-up portion is located on a tire radial side inner than the tire maximum width position, the tire is a run-flat tire; in that when H1 is a tire radial maximum length of the side reinforcing rubber in a tire widthwise cross section in a reference state where the tire is mounted to a rim and filled with a predetermined internal pressure with no load applied thereon, and H2 is a length of a straight line segment connecting a tire radial outermost point of the bead filler and a tire radial outermost point of the bead core, H1 and H2 satisfy 1.8 ≤ H 1 / H 2 ≤ 3.5; in that the 50% stretch modulus of the side reinforcing rubbers is 1.5 to 6.0 Mpa; in that a maximum thickness of the side reinforcing rubbers measured in a direction perpendicular to the carcass is 6 mm or less; and in that the tire has an air volume of 15000 cm 3.