The SAE forty viscosity ranking is made to get the job done very well underneath very higher temperatures. Large motor-load cases will also be correctly lubricated using an SAE forty body weight oil. The Mercruiser outdrive diagram offers a visual illustration of different areas that make up this energy system. https://automotivetechnician17387.blog2freedom.com/27280458/considerations-to-know-about-types-of-oil-goes-in-a-mercruiser-outdrive