Your engine’s top-end is sparsely lubricated and prone to the development of performance-robbing deposits. It’s also highly susceptible to corrosion, an issue compounded by the prevalence of ethanol in today’s fuel. AMSOIL Upper Cylinder Lubricant is designed to solve those issues. Its AMSOIL-exclusive, powerful formulation helps maximize engine power and performance while increasing engine life. And unlike competing fuel additives, AMSOIL Upper Cylinder Lubricant works.