Abstract: Outer longitudinal grooves extend in the circumferential direction of a pneumatic tire in a zigzag fashion. A plurality of first transverse grooves situated at an outer portion of a tread portion extend toward one side in a circumferential direction of the tire and is connected to the outer longitudinal grooves, as it gradually extends from an outer side of a width direction of the tire to an inner side thereof. A plurality of second transverse grooves situated at an inner portion of the tread portion extends toward the one side in the circumferential direction of the tire and is connected to outer longitudinal grooves, as it gradually extends from the inner side of the width direction of the tire to the outer side thereof.

Abstract: An object of the present invention is to provide a tire for heavy load, which exhibits good performances in both fuel efficiency and drainage. One example of the pneumatic tire comprising a tread portion and a pair of circumferential main grooves formed in a ground contact surface of the tread portion to section the ground contact surface of the tread portion into the central region and respective side regions, wherein the tire further comprises three circumferential narrow grooves formed in the central region to demarcate four rib-like center land portions in the central region; and the central region has a structure in which openings of the circumferential narrow grooves are closed so that the rib-like center land portions adjacent to each other with the circumferential narrow grooves therebetween are in contact with and thus supported by each other when the tire is in contact with the ground.

Abstract: Outer longitudinal grooves extend in the circumferential direction of a pneumatic tire in a zigzag fashion. A plurality of first transverse grooves situated at an outer portion of a tread portion extend toward one side in a circumferential direction of the tire and is connected to the outer longitudinal grooves, as it gradually extends from an outer side of a width direction of the tire to an inner side thereof. A plurality of second transverse grooves situated at an inner portion of the tread portion extends toward the one side in the circumferential direction of the tire and is connected to outer longitudinal grooves, as it gradually extends from the inner side of the width direction of the tire to the outer side thereof.