Patent ID: 8230890

Claim:
A pneumatic tire, comprising: five main grooves each extending in a tire circumferential direction and disposed in a tread surface at predetermined intervals in a tire width direction, the five main grooves including a single first main groove, two second main grooves and two third main grooves, the single first main groove being disposed on a tire equator, the two second main grooves being respectively disposed on two sides of the first main groove in the tire width direction, and each of the two third main grooves being disposed on an outer side of its neighboring second main groove in the tire width direction; first lateral grooves each extending in the tire width direction and disposed between the first main groove and each second main groove at predetermined intervals in the tire circumferential direction; second lateral grooves each extending in the tire width direction and disposed between each second main groove and its neighboring third main groove at predetermined intervals in the tire circumferential direction; and first blocks and second blocks formed in a center area of the tread surface between the two third main grooves, the first blocks being defined by the first main groove, the second main grooves and the first lateral grooves, as well as the second blocks being defined by the second main grooves, the third main grooves and the second lateral grooves; wherein the first main groove is made of a see-through groove extending in the tire circumferential direction with amplitude in the tire width direction, one end of the see-through groove being capable of being seen through the see-through groove from the other end of the see-through groove when the tread surface around the tire is assumed to be developed in a plane, a length of each first block in the tire circumferential direction is set longer than that of each second block in the tire circumferential direction by making the intervals of the first lateral grooves longer than the intervals of the second lateral grooves, and one sub-groove extending in the tire width direction is disposed in each first block, and one end of the sub-groove communicates with one of the second main grooves while the other end of the sub-groove is located inside the first block, the sub-groove including an outer side part adjoining the corresponding second main groove, the outer side part being shallower than the second main groove; and an inner side part adjoining the outer side part, the inner side part being shallower than the outer side part, and a boundary between the outer side part and the inner side part is located at a distance in a range of 15% to 40% of a length of the sub-groove in the tire width direction from an innermost end, on the tire equator side, of the sub-groove.