P.i. Performance Improver Gasoline Additive

P.i. improves fuel mileage an average of 2.3% and up to 5.7%. Reduces emissions such as hydrocarbons (HC) up to 15%, carbon monoxide (CO) up to 26% and nitrous oxides (NOx) up to 17%. Restores power and performance. Reduces the need for costly higher octane fuel. (API)

New formulation treats up to 30 gallons now instead of 20!

The #1 Best Selling non-oil product in the Sioux Falls store! And most of that is repeat sales. When I first used the current version I achieved a stunning 50 more miles from a tank of gas. This product restores lost performance which typically a professional injector cleaning procedure is used which costs 10X what this costs. Just use this every 5000 miles.

Gasoline Additive injector cleaner

Untreated Fuel Leads to Poor Engine Performance over time

A vehicle demonstrates its best efficiency and engine performance when it is new. As the engine ages, its performance suffers from gasoline fuel-generated deposits that form on the fuel injectors, intake valves and combustion chamber. Additives are required to control deposit formation.

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Maximum Deposit Clean-Up

AMSOIL P.i. features aggressive additives that attack the most common forms of engine deposits and limit their effects.

As seen proven best on Project Farm

Removes Fuel Injector Deposits

Most new engines feature gasoline direct-injection (GDI) to boost power and improve fuel economy. These injectors are located inside the intense heat and pressure environment of the combustion chamber, making them particularly vulnerable to deposits. Extreme pressure combined with incomplete fuel combustion can lead to dramatically increased soot (particulate matter) levels. Direct injection typically creates 30 to 40 times more soot than port fuel injectors (PFI). Even a minimal amount of injector fouling can lead to increased pollution and wear and decreased power and fuel economy.

Injector deposits:

  • Decrease efficiency, power and fuel economy
  • Increase exhaust emissions
  • Contribute to poor starting and rough idle

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

Fights Intake Valve Deposits

Valve deposits alter or restrict airflow patterns in the cylinder. They disrupt the balanced air/fuel ratio by momentarily absorbing and releasing fuel. The deposits can also cause valve sticking by getting in the way of the valve stem and guide.

Intake valve deposits:

  • Decrease power and efficiency
  • Increase exhaust emissions
  • Lead to potential valve failure

P.i. helps keep valves clean and moving freely.

  • Restores power and performance
  • Reduces need for costly higher-octane fuel
  • Reduces noise from carbon rap and pre-ignition
  • Controls pre-ignition “knock”
  • Improves fuel economy
  • Capless compatible

AMSOIL P.i. works as an ?emissions passer.? It is ideal for use prior to emissions inspections.

Cleans Combustion Chamber Deposits

Combustion chamber deposits increase compression and absorb heat during combustion. Later, they release that heat during the intake cycle. In some engines deposits can cause the piston to actually hit the cylinder head – a process known as “carbon rap.” The deposits can also flake off and become trapped between the valves and valve seat, resulting in compression loss.

Higher compression and stored heat increase the likelihood of pre-ignition “knock” when the fuel spontaneously combusts prior to spark ignition. This increases emissions and may cause engine damage. Most vehicles have sensors that adjust spark timing to prevent knock. Although audible ‘knock’ is controlled, power is lost from retarded timing and engine efficiency suffers. Higher octane fuels can be used to help prevent the phenomenon. As a vehicle ages, more-expensive, higher-octane fuel is needed to keep it operating at peak performance.

fuel injector cleanup using Amsoil PI

before and after treatment of injector cleaner by AMSOIL

Combustion chamber deposits:

  • Increase the possibility of “carbon rap”
  • Contribute to compression loss, difficult starting and rough idling
  • Increase the possibility of pre-ignition “knock” or “pinging”

P.i. fights combustion chamber deposits which helps restore power, control knock, increase fuel economy and reduce the need for higher-octane fuels.

Maximum Fuel Economy & Reduced Emissions

AMSOIL P.i. maximizes fuel efficiency by dissolving and removing deposits and other contaminants for improved power and overall performance. It improves fuel mileage up to 5.7 percent.1

P.i. works as an “emissions passer.” Running one tank of treated fuel through your engine helps pass emissions tests.

P.i. also reduces the following types of emissions:1

  • Hydrocarbons (HC) up to 15%
  • Carbon monoxide (CO) up to 26%
  • Nitrous oxides (NOx) up to 17%

Capless-Compatible Packaging

Many new vehicles have replaced traditional fuel caps with capless systems. The threads on most bottles restrict them from opening the flap inside the fuel neck and also make removing the bottle difficult. The P.i. bottle is fully compatible with capless fuel systems.


  • For use in gasoline powered 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.
  • For large gas tanks, treat with two bottles of P.i. Using more than two bottles per treatment is not recommended.
  • Safe for use with catalytic converters, oxygen sensors, oxygenated gas and up to 15 percent ethanol blended gas.
  • Do not use with diesel or E85 fuel or two-stroke engines.


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Buy in the Sioux Falls AMSOIL store at Exit 73 Tea Exit . or use this Online link to the Amsoil sale page if you are outside of the area.


Treat one full tank of gas up to 20 gallons with one bottle of P.i. For very large gas tanks, partially fill to 40 gallons and treat with two bottles of P.i. Using more than two bottles per treatment is not recommended. Treat gas every 4,000 miles of service (or 100 hours for marine, stationary and off-road gasoline-powered engines). P.i. helps pass emission tests by running one tank of treated fuel through the engine prior to testing. Safe for use with catalytic converters, oxygen sensors, oxygenated gas and 10 percent ethanol blended gas. Not recommended for two-cycle engines.

DANGER: Combustible. Harmful or fatal if swallowed. Harmful if inhaled. Skin and eye irritant. Read precautions on container before use.