Modern vehicles require minimal amounts of anti-wear additives in motor oil and emission requirements have removed ZDDP (which is short for Zinc dialkydithiophosphates) and other extreme anti-wear additives in modern motor oil. These additives are crucial for most vehicles manufactured before 1986 since they use flat tappet camshaft and lifters. These components undergo very high pressures and shear forces at their contact faces. These additives prevent scuffing and galling at these critical points of contact in your engine. To help get more life out of your classic vehicle, Mr. Gasket offers Zinc Engine Oil additive to give your ride that extra measure of protection that is not found in today’s motor oil. The special qualities of ZDDP in Mr. Gaskets Zinc Engine Oil additive give your flat tappet camshaft and lifters longer life and protection. It blends easily with most modern synthetic, petroleum or blended motor oils for that extra peace of mind. The 4oz. additive treats 5-7 quarts of motor oil making it is less expensive than racing oils that contain these additives. Ensure your classic vehicle lives a long life with Mr. Gaskets Zinc Engine Oil additive.