Loaded with ZDDP for added protection, MR50 offers an application specific product designed for this demanding performance environment. Driven's certified lubrication engineers have worked with marine engine builders to develop a first-in-class synthetic product that delivers performance and value. Excellent protection for high performance marine engines. Ideal for flat tappet cams, big blocks and blown marine engines. MR50 contains rust inhibitors for winter storage and defense against ethanol blended fuel. Viscosity typical of 15W-50.