A tire comprising a tread configured to come into contact with a road surface, wherein a ground contact surface obtained by mounting the tire on a normal rim, adjusting an internal pressure of the tire to 230 kPa, applying a load that is 70% of a normal load, to the tire, as a vertical load, and bringing the tire into contact with a planar road surface is a reference ground contact surface, wherein a shape index represented by a ratio of an equator ground contact length measured along an equator of the tire, to a reference ground contact length at a position corresponding to a width that is 80% of a maximum ground contact width, on the reference ground contact surface, is not less than 1.20 and not greater than 1.50, wherein at least three circumferential grooves are formed in the tread to form at least four land portions aligned in an axial direction, wherein, in the at least three circumferential grooves, a circumferential groove disposed on an outer side in the axial direction is a shoulder circumferential groove, wherein a land portion disposed outwardly of the shoulder circumferential groove in the axial direction is a shoulder land portion, and a land portion disposed inwardly of the shoulder circumferential groove in the axial direction is a middle land portion, characterized in that the tread comprises a cap layer, an intermediate layer formed such that a loss tangent (LTm) of the intermediate layer at 30°C is less than a loss tangent (LTc) of the cap layer at 30°C, and a base layer formed such that a loss tangent (LTb) of the base layer at 30°C is less than the loss tangent (LTm) of the intermediate layer at 30°C, wherein the loss tangent is determined in accordance with the standard of JIS K6394 under an initial strain of 10%, at a dynamic strain of 2%, at a frequency of 10 Hz in deformation mode tension, wherein the intermediate layer is disposed outwardly of the base layer in a radial direction, and the cap layer is disposed outwardly of the intermediate layer in the radial direction, and wherein, in the shoulder land portion, a thickness (Tm) of the cap layer at a center (Pm) of an axial width is less than a thickness (Tg) of the cap layer on the shoulder circumferential groove side. a tread configured to come into contact with a road surface, wherein a ground contact surface obtained by mounting the tire on a normal rim, adjusting an internal pressure of the tire to 230 kPa, applying a load that is 70% of a normal load, to the tire, as a vertical load, and bringing the tire into contact with a planar road surface is a reference ground contact surface, wherein a shape index represented by a ratio of an equator ground contact length measured along an equator of the tire, to a reference ground contact length at a position corresponding to a width that is 80% of a maximum ground contact width, on the reference ground contact surface, is not less than 1.20 and not greater than 1.50, wherein at least three circumferential grooves are formed in the tread to form at least four land portions aligned in an axial direction, wherein, in the at least three circumferential grooves, a circumferential groove disposed on an outer side in the axial direction is a shoulder circumferential groove, wherein a land portion disposed outwardly of the shoulder circumferential groove in the axial direction is a shoulder land portion, and a land portion disposed inwardly of the shoulder circumferential groove in the axial direction is a middle land portion, characterized in that the tread comprises a cap layer, an intermediate layer formed such that a loss tangent (LTm) of the intermediate layer at 30°C is less than a loss tangent (LTc) of the cap layer at 30°C, and a base layer formed such that a loss tangent (LTb) of the base layer at 30°C is less than the loss tangent (LTm) of the intermediate layer at 30°C, wherein the loss tangent is determined in accordance with the standard of JIS K6394 under an initial strain of 10%, at a dynamic strain of 2%, at a frequency of 10 Hz in deformation mode tension, wherein the intermediate layer is disposed outwardly of the base layer in a radial direction, and the cap layer is disposed outwardly of the intermediate layer in the radial direction, and wherein, in the shoulder land portion, a thickness (Tm) of the cap layer at a center (Pm) of an axial width is less than a thickness (Tg) of the cap layer on the shoulder circumferential groove side.