A tire comprising: a tread portion in contact with a road surface; a pair of bead portions each including a bead core and a bead filler; sidewall portions extending between the bead portions and the tread portion; a carcass layer folded back around the bead cores and extending in a toroidal shape between the bead portions; a belt layer arranged outwardly of the carcass layer in a tire radial direction, the belt layer reinforcing the tread portion; and reinforcing layers arranged adjacent to the carcass layer on a tread widthwise outer or inner side of the carcass layer, the reinforcing layer reinforcing the sidewall portion, the carcass layer including a body ply portion extending from the tread portion to the bead cores and folded-back ply portions each folded back around the corresponding bead core, wherein an end portion of each folded-back ply portion extends beyond a tire maximum width height, a height of the bead filler is 30% or less of a tire cross-sectional height, a tire radial inner end portion of each of the reinforcing layers is positioned inwardly, in the tire radial direction, of a tire radial outer end portion of the bead filler, in a cross section taken along the tread width direction of the tire and taken orthogonally to a tire circumferential direction, a maximum thickness of each of the reinforcing layers is smaller than a maximum thickness of the bead filler, a tread width, a length of the tread portion in the tread width direction, is 81% or more of a tire maximum width, and in the cross section taken along the tread width direction of the tire and taken orthogonally to the tire circumferential direction, a radius of curvature of the carcass layer on an extended line extending in the tread width direction through a tire maximum width position is in a range of 30 mm to 40 mm, characterized in that the tread portion includes: a plurality of circumferential grooves, land portions within a central region between shoulder circumferential grooves, and a shoulder land portion positioned outwardly of an outermost shoulder circumferential groove, wherein a lug groove included in the tread portion is arranged in the shoulder land portion and the lug groove is configured not to open to the circumferential groove, wherein the lug groove is not formed in land portions within a central area between the shoulder circumferential grooves, and wherein a siping with a groove width of 1 mm or less is used in the land portions within the central region. a tread portion in contact with a road surface; a pair of bead portions each including a bead core and a bead filler; sidewall portions extending between the bead portions and the tread portion; a carcass layer folded back around the bead cores and extending in a toroidal shape between the bead portions; a belt layer arranged outwardly of the carcass layer in a tire radial direction, the belt layer reinforcing the tread portion; and reinforcing layers arranged adjacent to the carcass layer on a tread widthwise outer or inner side of the carcass layer, the reinforcing layer reinforcing the sidewall portion, the carcass layer including a body ply portion extending from the tread portion to the bead cores and folded-back ply portions each folded back around the corresponding bead core, wherein an end portion of each folded-back ply portion extends beyond a tire maximum width height, a height of the bead filler is 30% or less of a tire cross-sectional height, a tire radial inner end portion of each of the reinforcing layers is positioned inwardly, in the tire radial direction, of a tire radial outer end portion of the bead filler, in a cross section taken along the tread width direction of the tire and taken orthogonally to a tire circumferential direction, a maximum thickness of each of the reinforcing layers is smaller than a maximum thickness of the bead filler, a tread width, a length of the tread portion in the tread width direction, is 81% or more of a tire maximum width, and in the cross section taken along the tread width direction of the tire and taken orthogonally to the tire circumferential direction, a radius of curvature of the carcass layer on an extended line extending in the tread width direction through a tire maximum width position is in a range of 30 mm to 40 mm, a plurality of circumferential grooves, land portions within a central region between shoulder circumferential grooves, and a shoulder land portion positioned outwardly of an outermost shoulder circumferential groove,