Due to government regulations, many of today's oils are missing critical ingredients needed for optimum engine protection. For this reason, engineers at COMP Cams and Endure Performance Lubricants have designed ZDDP-enhanced Muscle Car and Street Rod Engine Oils in 10W-30 and 15W-50 weights. After all, who knows more about how to protect the parts in your engine than the company that has defined engine performance for nearly 35 years. These new oils are specifically designed to be used in engines that experience extended periods of storage. Both weights utilize a blended synthetic formula fully approved for use in engines originally equipped with mineral oil. They provide all the benefits of mineral oil without the unwanted extras that lead to rust and corrosion. Designed for regular use, these oils will not create sludge, varnish or choke internal engine surfaces, and they are compatible with all gaskets and seals. The Muscle Car and Street Rod Engine Oils contain corrosion fighting additives, detergents and optimum amounts of ZDDP (Zinc & Phosphorous) for anti-wear protection, even after long periods of storage. The heavily tested and dyno proven oils improve cold starts and protect internal engine components, particularly the camshaft and lifters, in both flat tappet and roller valve trains. The COMP Cams Muscle Car and Street Rod Engine Oils are fully-formulated and require no additives or supplements. In addition, both popular weights are fully compatible with gasoline and methanol.