Unconjugated cyclopolyene copolymer, rubber composition, and use

A tire provided with a tire tread made from a rubber composition comprising (A) a random copolymer based on non-conjugated cyclic polyene comprising structural units originated from one or more alpha -olefins (A1) and originated from one or more non-conjugated cyclic polyene (A2), the said random copolymer having a content of the structural unit(s) originated from one or more alpha -olefins (A1) in the range of 93 to 70 mole %; a content of the structural unit originated from one or more non-conjugated cyclic polyene (A2) in the range of 7 to 30 mole %; an intrinsic viscosity Ä eta Ü , determined in decalin at 135 DEG C, in the range of 0.01 to 20 dl/g; a glass transition temperature (Tg) of not higher than 40 DEG C; and an iodine value in the range of 50 to 150, and (B) a rubber based on diene, in a weight proportion of äthe random copolymer based on non-conjugated cyclic polyene (A)ü versus äthe rubber based on diene (B)ü in the range from 60/40 to 0.1/99.9 exhibits a superior braking performance and, compatible therewith, a superior driving fuel cost aspect.