A tire comprising: a tread section with a circumferential groove portion formed to extend in a tire circumferential direction (tcd); and a plurality of projection parts provided on a groove bottom (50B2) of the circumferential groove portion, wherein each of the projection parts extends from one (50B1) of side walls forming the circumferential groove portion to the other side wall (50B3) opposed to the one side wall (50B1), the projection parts are arranged at predetermined intervals in the circumferential groove portion, and a relationship of TWf/cosθf≤0.9W is satisfied in a tread face view of the tire where W denotes a groove width of the circumferential groove portion, TWf denotes a width of the projection parts in a direction orthogonal to an extending direction (x) of the projection parts, and θf denotes an angle formed by the extending direction (x) of the projection parts and the circumferential groove center line in a direction opposite to a rotation direction of the tire, a lateral groove portion extending at an inclined angle (φ) of 15 degrees to 60 degrees, both inclusive, with respect to the tread width direction (twd) and opening to the circumferential groove portion, characterised in that the one side wall (50B1) is provided with a recess portion for guiding air flow flowing through the lateral groove portion in one direction of the tire circumferential direction (tcd); the recess portion is triangular in the tread face view of the tire and is located at a location opposed to where the lateral groove portion opens to the circumferential groove portion; a vertex of the recess portion is located on a position which is located in the extending direction of the lateral groove portion and displaced from a center line of the lateral groove portion in a direction orthogonal to the extending direction of the lateral groove portion, and a relationship of 1.25L<P≤10L is satisfied in the tread face view of the tire where L denotes a length of the projection parts along the circumferential groove center line passing a widthwise center of the circumferential groove portion, and P denotes the predetermined intervals. a tread section with a circumferential groove portion formed to extend in a tire circumferential direction (tcd); and a plurality of projection parts provided on a groove bottom (50B2) of the circumferential groove portion, wherein each of the projection parts extends from one (50B1) of side walls forming the circumferential groove portion to the other side wall (50B3) opposed to the one side wall (50B1), the projection parts are arranged at predetermined intervals in the circumferential groove portion, and a relationship of TWf/cosθf≤0.9W is satisfied in a tread face view of the tire where W denotes a groove width of the circumferential groove portion, TWf denotes a width of the projection parts in a direction orthogonal to an extending direction (x) of the projection parts, and θf denotes an angle formed by the extending direction (x) of the projection parts and the circumferential groove center line in a direction opposite to a rotation direction of the tire, a lateral groove portion extending at an inclined angle (φ) of 15 degrees to 60 degrees, both inclusive, with respect to the tread width direction (twd) and opening to the circumferential groove portion, characterised in that the one side wall (50B1) is provided with a recess portion for guiding air flow flowing through the lateral groove portion in one direction of the tire circumferential direction (tcd); the recess portion is triangular in the tread face view of the tire and is located at a location opposed to where the lateral groove portion opens to the circumferential groove portion; a vertex of the recess portion is located on a position which is located in the extending direction of the lateral groove portion and displaced from a center line of the lateral groove portion in a direction orthogonal to the extending direction of the lateral groove portion, and a relationship of 1.25L<P≤10L is satisfied in the tread face view of the tire where L denotes a length of the projection parts along the circumferential groove center line passing a widthwise center of the circumferential groove portion, and P denotes the predetermined intervals.