A thermoplastic vulcanizate composition includes (a) a crystalline thermoplastic polyolefin comprising alpha-olefin monomers having from 2 to 5 carbon atoms, (b) a rubber block interpolymer comprising a first block and a second block having differing chemical or physical properties from the first block, the first block is derived from ethylene, a first alpha-olefin monomer having from 3 to 10 carbon atoms, and a first diene monomer having from 2 to 25 carbon atoms, the second block is derived from ethylene, a second alpha-olefin monomer having from 3 to 10 carbon atoms, and optionally a second diene monomer having from 2 to 25 carbon atoms, and an amount of the block interpolymer in the composition being greater than an amount of the thermoplastic polyolefin in the composition, and (c) a curative system.