Rubbery blend containing trans isoprene-butadiene copolymer

A rubber composition is disclosed comprising 2 phr to 45 phr of a trans-1,4-isoprene-butadiene copolymer which has from 4 weight percent to 16 weight percent 1,3-butadiene repeat units and from 84 weight percent to 96 weight percent isoprene repeat units, wherein the trans-1,4-isoprene-butadiene copolymer has a Mooney ML 1+4 viscosity within the range of from 35 to 80, and 55 phr to 98 phr of at least one other elastomer. The rubber composition may be used in a tire tread or sidewall.