Tire with recessed portions formed on buttress portion

A tire, comprising:

• a tread which contacts a road surface and is provided on an outer side of the carcass in a tire radial direction;
• side walls provided on an inner side of the tread in the tire radial direction;
• and a buttress portion provided between the tread and the side walls, and does not contact a smooth road surface when the road surface is smooth and a proper internal pressure and a proper load are applied to the tire,
• wherein a recessed shoulder region is provided on the buttress portion, the recessed shoulder region having a predetermined width and extending along the tire circumference direction, and on the recessed shoulder region, formed are a plurality of recessed portions recessed from a surface of the tire, and a surface portion where the recessed portions are not formed, the recessed portion is formed in a plurality in a tread width direction and the tire circumference direction,
• a ratio of an area occupied by the recessed portions in the recessed shoulder region is equal to or greater than 60%,
• in the surface of the tire, a width of the recessed shoulder region along the tire radial direction is represented by L1, and a length of the recessed shoulder region along the tire circumference direction is represented by L2,
• a volume of the recessed portions is represented by V, and a depth of a deepest portion of the recessed portions is represented by D,
• the relation of V≧L1·L2·(D/2) is satisfied,
• the recessed portion is polygonal on the surface of the tire, and a side forming the recessed portion is slanted in relation to the tire circumference direction, and
• wherein an end of the recessed portion positioned on an innermost side of the recessed shoulder region in the tread width direction is provided in a position, in the circumferential direction, that is substantially the same as a short thin groove.