Abstract: Thermoplastic polyolefin compositions of a substantially crystalline polyolefin that is a homopolymer of ethylene, propylene or butylene or a copolymer of propylene and a C.sub.3 -C.sub.10 alpha-olefin; about 10% to 50% by weight of a first substantially amorphous polyolefin of a terpolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin and a diene monomer and having a Mooney Viscosity (ML.sub.1+4, 100.degree. C.) of between about 10 and about 120; optionally, a copolymer of ethylene and a C.sub.3 -C.sub.10 alpha-olefin may be present; and about 1 to 20% by weight of a second substantially amorphous polyolefin having a number average molecular weight of between about 1,000 and 15,000 and including (a) a copolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin; (b) a terpolymer of ethylene with a C.sub.3 -C.sub.10 alpha-olefin and a diene monomer; (c) a block copolymer that includes blocks of a C.sub.3 -C.sub.

Abstract: A method of making articles of manufacture, such as automobile bumpers and other components, formed from thermoplastic olefin compositions, having improved resistance to gasoline and other fluids when painted with flexible coatings such as two component polyurethane paints, and the like, are disclosed. The compositions used to form these articles include a thermoplastic olefin such as crystalline polypropylene, crystalline polyethylene or mixtures thereof with a first rubber component of an ethylene propylene diene rubber having a high molecular weight and a second rubber component of an ethylene propylene diene rubber having a low molecular weight, wherein the first rubber component has a molecular weight of 4 to 200 times that of the second rubber component.