TIRE

A tire having a tread portion provided with a circumferential groove. Of the opposite groove side walls of the circumferential groove, at least one groove side wall to be positioned on the inside of a vehicle is provided with a lower side wall portion extending from a groove bottom, and a protruding portion extending from the lower side wall portion to have a radially outer edge. The protruding portion protrudes toward the groove widthwise center from a reference line X defined by a radially outwardly extended line from the lower side wall portion. The protruding portion comprises a sloped portion extending obliquely from the radially outer edge to the tread surface.