P.i. Performance Improver Gasoline Additive API
- Restores up to 14% horsepower1
- Reduces need for costly higher-octane fuel
- Reduces noise from carbon rap and pre-ignition
- Controls pre-ignition "knock"
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.
Data Bulletin and Field Study
Removes Stubborn Deposits to Restore Power and Performance
- AMSOIL P.i. restores up to 14% horsepower in one tank of gasoline.1
- Fights intake valve and combustion chamber deposits which helps restore power, control knock and reduce the need for higher-octane fuels.
- Restores GDI fuel injectors up to a 100 percent flow rate.2

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.