Top quality oil for gasoline and diesel engines. Exceeds FC-W requirements. Sierra goes above and beyond what is required of marine engine oils with this full synthetic oil. It is a unique blend of a synthetic base and carefully selected additives to create an oil that provides better protection at startup, extreme running conditions, and while the engine is in storage. Sierra synthetic oils provide a more effective and longer lasting lubrication than conventional mineral based oils to extend engine life and improve fuel economy. Formulated to meet or exceed manufacturers specifications to stay compliant with engine warranties. Know your marine engine has the protection it needs by using Sierra full synthetic oil. Key Features Pure synthetic engine oil for gasoline and diesel marine engines Synthetic base with special selection of additives to provide corrosion protection Longer lasting lubrication than conventional mineral based oils Excellent engine protection at startup, under a wide range of operating conditions and while in storage Meets API SL/CF diesel specifications