An olefinic thermoplastic elastomer composition comprises ground tire rubber (GTR) sub-divided into crumbs; at least one polyolefin; at least one styrene block copolymer; at least one α-olefin-vinyl ester copolymer; at least one sulfur scavenger; at least one blocking agent; at least one disproportioning agent; at least one free-radical donor acceptor; and at least one deflocculant. The product produced from the olefinic thermoplastic clastomer composition comprises a continuous matrix wherein the sub-divided GTR crumbs are homogeneously dispersed within the polyolefin matrix and wherein the sub-divided GTR crumbs have a shell and core structure.