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)
Package sizes include:
12-oz. Bottle
12-oz. Bottles (case of 12)
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. Reduces noise from carbon rap and pre-ignition. Offers better vehicle drivability and smoother operation.
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.
Today's fuels, however, lack sufficient treatments of either enough additives or high quality additives. Fuel system deposits result in the following:
• Lost fuel economy
• Lost power and poor throttle response
• Failed emission tests
• Poor drivability - surging, hesitation, stalling, rough idle
• Engine knocking (pinging) and rap
• Difficult starts
AMSOIL
P.i. is the most potent gasoline additive available today. As a concentrated detergent, it is unsurpassed in cleaning combustion chamber deposits, intake valve deposits and port fuel injector deposits. AMSOIL P.i. helps maintain peak engine efficiency, fuel economy, power and drivability in newer low mileage engines. In engines with accumulated deposits, testing showed AMSOIL P.i. provided the following clean-up benefits after only one tank of gasoline:
• Improves fuel mileage an average of 2.3% and up to 5.7%
• Reduced emissions
Port Fuel Injector Deposits form after the engine has been shut down and there is no gasoline flowing through the injectors. During this "hot soak" period the injectors heat up and the gasoline remaining in the injectors degrades and forms deposits. This can happen very quickly with the use of poor quality gasoline and short trip driving. Because the clearances within the injectors are extremely tight and injectors must deliver precise amounts of "atomized" fuel, even small amounts of deposits can cause injectors to malfunction. Fuel flow is reduced and spray patterns are disrupted, decreasing engine efficiency, power and fuel economy, while increasing exhaust emissions.
Intake Valve Deposits form on the intake side or back side of the valves. As deposits increase, they restrict airflow and alter airflow patterns in the cylinder. The deposits disrupt the balanced air/fuel ratio by momentarily absorbing and releasing fuel, and they can cause valve sticking by getting in the way of the valve stem and guide. Deposits also restrict proper seating, and the valves may be burned. Intake valve deposits cause lost engine power, increased emissions, poor engine efficiency and potential valve failure.
Combustion Chamber Deposits form on the top of the pistons and on the cylinder heads. They increase compression and absorb heat during combustion to later release it during the intake cycle. In some engines with tight squish domes, combustion chamber deposits cause the piston to actually hit the cylinder head. This is referred to as combustion chamber deposit interference or “carbon rap.” Combustion chamber deposits also flake off as they get large, and these flakes can get trapped between the valves and valve seat, resulting in compression loss, difficult starting and rough idle.
Higher compression and stored heat cause increased intake fresh charge temperatures and the increased likelihood of pre-ignition “knock” or “pinging” when the fuel spontaneously combusts prior to spark ignition. This increases emissions and may cause engine damage. Many of today’s cars have “knock” sensors that adjust spark timing to prevent knock.
Although audible knock is controlled, power is lost from retarded timing. Higher octane fuels of 4-5 octane numbers can be used to help prevent knock, an effect called “octane requirement increase.” As a vehicle ages, more expensive higher octane fuel is needed to keep it operating at peak performance. By cleaning combustion chamber deposits, knock is controlled, power is restored, fuel economy increases and higher octane fuels are less necessary for peak performance.
Maximum Fuel Economy
AMSOIL P.i. maximizes fuel efficiency by dissolving and removing fuel system deposits and other contaminants for improved power and overall performance.
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 or 100 hours of service. 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.
This product is not expected to cause health concerns when used for the intended application and according to the recommendations in the Material Safety Data Sheet (MSDS).
Click here to view the MSDS Data Sheet for AMSOIL API.
Keep out of the reach of children. Don't pollute. Return used oil to collection centers.
Product Name: P.I Performance Improver (API)
Current Rating: 4.91 out of 5 stars
Votes & Reviews: 371 vote(s) and 230 user reviews.
Reviewed by Ryan the lion: 
I purchase PI, every oil change. I feel that my 2010 Tahoe dose benefit from this fluid as it's high in mileage and the environment here is harsh for any vehicles. I really don't see any fuel mileage increase, but it's the engine is running smoother in the cold mornings.
It's a nice treat for the "Tank".
Reviewed by Rich:
I used this in one of my older high mileage cars and it seemed to really do what it was intended. I will use this again and probably even in the newer ones.
Reviewed by Hank:
Been using for years. Keeps moisture out and clean injectors
Reviewed by rooroo:
Great product
Reviewed by Dan:
This product works very well and I like using it, however it is expensive which limits my ability to purchase more and use it more ofter.
Reviewed by Dan:
This product works very well and I like using it, however it is expensive which limits my ability to purchase more and use it more ofter.
Reviewed by JMC:
Seem work good additive pi performance gasoline additive with 93 fuel noticed much more effective clean more deep work as great
Reviewed by ironrail:
I use this product every time that I change the oil on my vehicles. I drive about 1000 miles per week so I change my oil frequently. It does what it says that it does. i wish it were already added to the gas at the pumps. My vehicles run as smooth as silk.
Reviewed by John R:
Used this product many times at every oil change all but good results.
Canada
United States
It's a treat
I purchase PI, every oil change. I feel that my 2010 Tahoe dose benefit from this fluid as it's high in mileage and the environment here is harsh for any vehicles. I really don't see any fuel mileage increase, but it's the engine is running smoother in the cold mornings.
It's a nice treat for the "Tank".