• Restores up to 14% horsepower¹
• Restores GDI fuel injectors to 100% flow rate after one tank of fuel²
• Improves fuel economy
• Reduces need for costly higher-octane fuel
• Helps prevent carbon rap
• Controls pre-ignition knock
• Compatible with capless fuel systems

¹Based on third-party testing in a 2016 Chevrolet* Silverado* 1500, 5.3L V-8 GDI with 100,616 miles, using one tank treated with AMSOIL P.i. Actual results may vary.
²ASTM D5598(M) – 2013 Buick Regal test vehicle.

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.