AMSOIL P.i.® Performance Improver Gasoline Additive

  • 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.

Product Overview

AMSOIL P.i. is a potent gasoline performance improver with concentrated detergent that aggressively cleans stubborn, power-robbing deposits from injectors, valves and the combustion chamber. Effective in port and direct injection systems. Bottle compatible with capless fuel systems. Cleans entire fuel system in one tank of gasoline. For use with cars and trucks. Treats up to 30 gallons. Add entire bottle to tank at fill-up. For best results, clean your fuel system with P.i. every 4,000 miles (6,400 km). Do not use with diesel or two-stroke engines.

MAXIMUM DEPOSIT CLEAN-UP

  • Helps keep valves clean and moving freely.
  • Aggressive additives attack the most common forms of engine deposits and limit their effects.

REMOVES FUEL-INJECTOR DEPOSITS

  • P.i. removes deposits and keeps injectors functioning as they should.
  • Testing shows P.i. restored GDI fuel injectors to a 100% flow rate after one tank of fuel.2

RESTORES HORSEPOWER

  • Third-party testing demonstrated performance of P.i. using a 2016 Chevrolet* Silverado* with 100,616 miles on the odometer.
  • Following a single treatment with P.i., the truck measured an incredible 14% improvement in horsepower.1

CLEANS COMBUSTION CHAMBER DEPOSITS

  • Fights combustion chamber deposits to help restore power, control knock, increase fuel economy and reduce the need for higher-octane fuels.
  • Protects against compression loss, difficulty starting and rough idling.
  • Reduces possibility of “carbon rap,” when deposit buildup causes the piston to hit the cylinder head.
  • Decreases the possibility of pre-ignition “knock” or “pinging.”

CAPLESS-COMPATIBLE BOTTLE

  • Bottle is fully 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.

Ready to buy or need help selecting the right product?

 

Product information checked: September 2026. Product formulations, specifications, applications, availability and published claims can change.
For the latest official information, consult the AMSOIL Corproate Website.

Upcoming Shows
21st Annual Car Show for HOPE
21st Annual Car Show for HOPE
Sept. 19, 2026 | Rock & Brews | Oviedo, Florida ...
Blog
Comparison of the former and new Technilube.com homepages
Welcome to the New Technilube.com Blog and Site!

If you found this post, you have discovered the Technilube.com blog on the new site. Welcome.

Technilube.com has been online since ...

Facts & Info
Oils Against Oils
Oils Against Oils
Originally published in Fast Fours & Rotaries in July 1998, “Oils Against Oils” reports a performance-car engine test comparing synthetic ...
Event Coverage
VanFest: LIFTOFF! 2026
VanFest: LIFTOFF! 2026
February 7-8 | Space Coast Daily Park | Melbourne, Florida ...
Heritage Spotlight
My Dad and AMSOIL
My Dad and AMSOIL

My father was an AMSOIL Dealer in the 1970s and 1980s, and that’s where I first learned about the product ...