A lightweight tire with reduced rolling resistance and improved steering stability without decreasing tire durability, said tire containing a sidewall made of a rubber composition including 20 to 70 parts by weight of an inorganic filler, and 5 to 35 parts by weight of polypropylene powder, based on 100 parts by weight of a rubber component, which satisfies the following equation: (amount of polypropylene powder).gtoreq.(amount of inorganic filler+amount of polypropylene powder)/2.