Random thermoplastic ethylene copolymers can be used to increase the elongation to break and toughness of thermoplastic vulcanizates. Polypropylene is a preferred thermoplastic phase. The rubber can be olefinic rubbers. Random thermoplastic ethylene copolymers are different from Ziegler-Natta ethylene copolymers as the compositional heterogeneity of the copolymer is greater with Ziegler-Natta copolymers. This difference results in substantial differences in properties (elongation to break and toughness) between thermoplastic vulcanizates modified with random thermoplastic ethylene and those modified with Ziegler-Natta ethylene copolymers. An increase in elongation to break results in greater extensibility in the articles made from a thermoplastic vulcanizate.