Complete Fuel System Cleaner – Unsurpassed at Cleaning Fuel Injectors, Carburetor, Intake Valves, Combustion Chamber, Cylinder Heads and Piston Tops
Formulated for Gasoline Direct Injected (GDI), Port Fuel Injected and Carbureted Engines
One Treatment Can Help Pass Emissions Test!
An effective one-tank complete fuel system cleaner, AMSOIL P.i. Performance Improver Gasoline Additive (Product Code: API) is more potent than other fuel additives on the market. AMSOIL P.i. effectively cleans the total fuel system – everything the fuel touches. It is unsurpassed in cleaning both port and gasoline direct fuel injector, carburetor, intake valve, combustion chamber, cylinder head and piston top deposits in only one single tank of gasoline, removing deposits that have built up over thousands of miles.
Just one bottle of AMSOIL P.i. Performance Improver treats one tank of gas every 4,000 miles. Removing engine deposits with P.i. effectively improves fuel economy, reduces emissions, restores power, performance and acceleration, reduces octane requirements, increases engine life and reduces maintenance costs. Running just one tank of gasoline treated with AMSOIL P.i. Performance Improver Gasoline Additive through the engine can help pass emissions tests!
AMSOIL P.i. helps maintain peak engine efficiency, fuel economy, power and drivability in newer low-mileage engines. In engines with accumulated deposits, testing shows AMSOIL P.i. provided the following clean-up benefits after only one tank of gasoline:
- Increased fuel economy an average of 2.3% and up to 5.7%
- Reduces emissions:
- hydrocarbons emissions (HC) up to 15% (unburned fuel)
- carbon monoxide emissions (CO) up to 26% (burned fuel)
- nitrous oxides emissions (NOx) up to 17%
- Restores engine power and throttle response
- Reduces the need for costly higher octane fuel
- Reduces noise from carbon rap and pre-ignition engine knock
- Better drivability (better engine idle, less engine hesitation and stalling)
- Smoother operation
Use AMSOIL P.i. in gasoline engines in passenger cars and trucks. AMSOIL P.i. Gasoline Additive is safe for use with catalytic converters, oxygen sensors, oxygenated gas and 10% ethanol blended gas.
AMSOIL p.i. Performance Improver Study (815.1 kb)
AMSOIL P.i. Performance Improver Gasoline Additive Product Code Pkg/Size APICN-EA 12-Ounce Bottle APICN-CA 12-Ounce Bottles (case of 12)
Fuel Injected Engines Replace Carbureted Engines
In response to Environmental Protection Agency (EPA) fuel economy and emissions regulations, fuel injection systems replaced carburetors in new vehicles in the 1980s. Fuel injectors allow more precise control of fuel than carburetors, improving fuel efficiency and minimizing emissions. However, in order to work efficiently, they must be kept clean.
Untreated Fuel Leads to Engine Problems
A vehicle demonstrates its best efficiency and engine performance when it is new. As the engine ages, its performance suffers from gasoline-generated deposits that form on the fuel injectors, intake valves and combustion chamber. Fuel system deposits result in the following:
- Lost fuel economy
- Lost engine power
- Starting problems
- Rough idle
- Engine stalling
- Poor acceleration
- Poor throttle response
- Failed emission tests
- Engine knocking (pinging) and rap
Why Use a Gasoline Additive?
Gasoline contains impurities that contribute to the deterioration of the combustion process. Additives are required to control deposit formation, however today’s fuels lack sufficient treatments. Fuel either doesn’t contain enough additives or the additives are not of the highest quality. In fact, deposits begin forming immediately even with refinery treated gasoline.
Combustion chamber deposits create hot spots that cause gasoline to ignite prematurely, which is often the cause for engine knock. Intake valve deposits soak up fuel like sponges, which disturbs the precise air fuel ratio, again leading to poor engine performance and sometimes knock. And even small amounts of deposits can cause clogged fuel injectors. Additives are required to control this deposit formation.
AMSOIL P.i. Performance Improver Gasoline Additive improves combustion efficiency, intake performance and increases injector fuel flow. Whether deposits have built up over a relatively low number of miles, or they have accumulated over 100,000 miles, AMSOIL PI Gasoline Additive effectively removes them. Because fuel injector deposits usually build up slowly over time, motorists often attribute the decreased performance to the increased age of the vehicle. When the deposits are removed in only one tank of gasoline, the performance improvement is immediate and significant.
Cleans Port Fuel Injector Deposits to Improve Fuel Economy, Reduce Emissions
Port fuel injectors transfer liquid gasoline from the tank and spray it in a fine mist into the intake air stream, increasing surface area and allowing the gasoline to evaporate into a gaseous state as it enters the engine.
By measuring oxygen, the oxygen sensor in the exhaust stream is able to calculate how much gasoline the injectors are spraying, as well as the air fuel ratio. Although vehicles are usually equipped with many fuel injectors (one per cylinder), only one oxygen sensor monitors them all. Through the oxygen sensor, the computer is able to determine if the engine is receiving the right amount of fuel. Deposit build up on the injectors reduces the fuel flow. When the computer determines that the engine is not receiving enough fuel, it increases fuel flow from all the injectors in the fuel system. Although this solution would work well if all the injectors lost fuel flow at the same rate, injectors almost always plug at different rates based upon their operating temperatures (inboard cylinders typically run hotter) and individual manufacturing tolerances.
Port fuel injector deposits have a significant impact on fuel economy and emissions because they plug injectors at uneven rates and the engine cannot compensate for individual cylinders. For example, a four cylinder engine could have two plugged injectors, while the other two may only be mildly plugged or not plugged at all. The oxygen sensor indicates to the computer that the engine is not receiving enough fuel, so it increases the fuel supply to all four cylinders. Now the two injectors that were plugged are providing more fuel, but it still may not be enough, while the two injectors that weren’t plugged are providing more fuel than necessary. As a result, it creates a situation where two cylinders are running rich and the other two are running lean.
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 fuel injector malfunction. Fuel flow is reduced and spray patterns are disrupted, decreasing engine efficiency, power and fuel economy, while increasing exhaust emissions.
Cleaning port fuel injector deposits allows the engine to operate as it was designed, improving fuel economy, lowering emissions and contributing to improved drivability (reduced engine stalls, hesitation and rough idle) and increased engine power. As a fuel injector cleaner, AMSOIL P.i. Performance Improver Gasoline Additive removes deposits for increased injector fuel flow:
Cleans Intake Valve Deposits for Better Intake Performance
The role of the intake valve is to act as a doorway. It opens to allow fuel and air into the combustion chamber, then it closes, sealing off the combustion chamber for combustion and building up pressure in the cylinder.
Intake valve deposits are present in some quantity in nearly every vehicle on the road. While some vehicles run trouble-free with a small amount of deposits, other vehicles are more sensitive to them, especially modern vehicles. The deposits tend to build up on the back side of intake valves, where they act like a hard carbonaceous sponge that absorbs fuel, disrupting the balanced air fuel ratio. The computer tells the injectors how much fuel to spray, but instead of it all entering the combustion chamber, a portion of it becomes trapped in the deposits. Thus, the combustion chamber has the correct level of oxygen, but not enough fuel, creating a lean misfire that leads to drivability issues such as engine stalls, hesitation, and rough idle. By removing these deposits, all the fuel from the injectors is able to enter the combustion chamber.
Valve sticking is another problem created by intake valve deposits. Deposits build up where the valve stem goes through the guide, causing it to stick in the guide. Although the camshaft has more than enough force to open the valve, it has trouble closing it.
Heat must escape from the engine during combustion and post-combustion, and a great deal of it enters the intake valve. Once there, it has three ways of getting out of the engine. It can go up the stem, into the guide and out to the coolant passages; it can go through the valve seat itself, into the head and into the coolant passages or it can escape the intake valve through the surface on the back side. Any fuel on the back side of that surface evaporates and contributes to the combustion process. Because deposits act as an insulator, they block a lot of this heat transfer and force the heat to go out through the valve seat or valve stem rather than coming back to the intake track to help evaporate the gasoline.
Intake valve deposits cause lost engine power, increased vehicle emissions, poor engine efficiency and potential valve failure. As shown in the before and after graph below, AMSOIL P.i. Performance Improver Gasoline Additive dramatically reduces intake valve deposits for better intake performance:
Cleans Combustion Chamber Deposits to Improve Combustion Efficiency
The combustion chamber is where fuel combustion takes place, and it is both the hottest location in the engine and the most difficult location to clean of deposits. Spark timing is very important in gasoline engines. Combustion must be timed so the fire develops maximum pressure once the piston has reached its peak. The role of the spark plugs is to start the fire and control the timing.
High levels of combustion chamber deposits can negatively affect this process. Like intake valve deposits, combustion chamber deposits are present in some quantity in nearly every vehicle on the road. When allowed to accumulate, they resemble mountains with peaks and valleys. Acting as insulators that hold heat, the peaks can become hot enough to act as a secondary ignition source, igniting and creating two combustion fronts (one from the spark plug and one from the secondary ignition source).
The two combustion fronts collide and bounce back and forth in the cylinder as a pressure wave, creating a knocking noise or pinging sound in the engine as the pressure wave hits the sides of the cylinder. This can lead to engine damage, including broken pistons and rings. Many of today’s cars have knock sensors that adjust spark timing to prevent knock; although engine knock is controlled, power is lost from retarded timing.
There are two ways to remedy the problem. The first is use of a higher octane gasoline that resists ignition in the presence of the secondary ignition source. The second remedy is to remove the secondary ignition source by removing the deposits. Removal of the secondary ignition source eliminates the need for higher octane gasoline, saving fuel expenses by allowing motorists to switch to less expensive lower octane gasoline.
Combustion chamber deposits also create a problem called combustion chamber deposit interference or “carbon rap.” In order to meet emission standards, many modern vehicles are designed to burn everything in the combustion chamber. To do so, the outside edges of the pistons are higher than the centers so that during the end of the combustion stroke, they naturally “squish” everything back to the center. Unburned material around the outside edges gets pushed back toward the flame. Because this design causes the outside piston to come very close to the cylinder head, large enough layers of deposits on both the cylinder head and piston top in an engine with tight tolerances can cause the piston to physically hit the cylinder head, creating a loud metallic banging sound, a problem particularly evident at cold startup.
A third problem attributed to combustion chamber deposits is flaking. Combustion chamber deposits are usually the driest of engine deposits due to the hot environments in the combustion chamber, and they are very susceptible to humidity. When humidity enters the cylinder, it causes the deposits to flake, come off in large chunks and exit the exhaust valve. The problem is that not all the deposits make it past the exhaust valve. Some remain on the valve seat when the valve closes, holding the exhaust valve open slightly and leading to lost engine compression, starting problems, rough idle, increased hydrocarbon emissions and a possible burned exhaust valve. To avoid this problem, it is necessary to clean combustion chamber deposits, ensuring they don’t flake off and cause problems.
By cleaning combustion chamber deposits, engine knock is controlled, emissions are reduced, engine power is restored, fuel economy increases and higher-octane fuels are less necessary for peak engine performance. As shown in the before and after graph below, AMSOIL P.i. Performance Improver Gasoline Additive dramatically reduces combustion chamber deposits for improved combustion efficiency:
Increase Fuel Economy
AMSOIL P.i. Performance Improver Gasoline Additive improves fuel economy by dissolving and removing fuel injector, intake valve and combustion chamber deposits and other contaminants for improved engine power and overall performance. As shown in the graph below, AMSOIL P.i. Gasoline Additive improves gas mileage an average of 2.3% and up to 5.7%. Although the Honda and two Toyota vehicles had the lowest levels of deposits prior to P.i. treatment, they experienced the largest fuel economy increases after treatment, indicating that even minimal levels of deposits can have significant effects on fuel economy. In fact, many smaller engines designed for maximum fuel efficiency are among the most sensitive to deposits.
Gasoline Direct Injection (GDI)
Gasoline direct injection (GDI) differs from port fuel injection in where the gasoline is introduced prior to combustion. In conventional port-injected fuel systems, the fuel/air mixture occurs in the intake manifold. In GDI engines, gasoline is injected directly into the combustion chamber under very high pressures, similar to how diesel engines operate. This results in better control of the air-fuel mixture, allowing greater power, torque and operating efficiency.
Most vehicle manufacturers are now producing vehicles incorporating GDI technology, with several reasons for their increased production. First, today’s injector systems are computer-controlled and capable of delivering extremely accurate and rapid distribution of atomized gasoline. The fuel can be sprayed directly at the hottest part of the combustion chamber, which is near the spark, improving efficiency. Second, because the fuel supply is more precisely controlled, combustion can occur at leaner air-to-fuel ratios. GDI engines use a very lean mixture of 40:1 or greater during light loading conditions. The lean ratio means less fuel is burned during combustion, increasing fuel economy. Finally, when atomized fuel is injected into cylinders at high pressure, the combustion chamber temperature decreases slightly, helping further increase efficiency.
The fuel injectors in GDI engines, located directly in the combustion chamber, are exposed to elevated temperatures and pressures. This severe environment makes them more susceptible to deposits that impede the spray pattern, reducing engine efficiency. AMSOIL P.i. contains powerful detergents that clean deposits that form in combustion chambers and on fuel injectors, improving fuel economy and reducing emissions.
Although modern vehicles are equipped with fuel injection systems, there are still a number of older and classic carbureted cars on the road. AMSOIL P.i. Gasoline Additive works just as effectively in carburetors as it does in fuel injectors, intake valves and combustion chambers. AMSOIL P.i. Gasoline Additive effectively cleans the back sides of carburetor plates, the idle air passages and all of the fuel portals just as well as it cleans the components of a fuel injection system.
Helps Pass Emissions Test
AMSOIL P.i. Performance Improve Gasoline Additive helps pass emission tests by running one tank of treated fuel through the engine prior to testing.
AMSOIL P.i. Gasoline Additive is safe for use with catalytic converters, oxygen sensors, oxygenated gas and 10% ethanol blended gas. Not recommended for 2-stroke engines.
One 12-ounce bottle of AMSOIL P.i. Gasoline Additive treats one full tank of gas up to 20 gallons. For very large gas tanks, partially fill to 40 gallons and treat with two bottles of AMSOIL P.i. Gasoline Additive; using more than two bottles per treatment is not recommended. Treat gas every 4,000 miles or 100 hours of service for marine, stationary and off-road gasoline-powered engines.
Shipping for Online and Catalog Customers
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For more information, please visit the AMSOIL, Inc. website: AMSOIL Shipping, Sales Tax and Product Return Guidelines
Please visit the AMSOIL, Inc. website: AMSOIL Shipping, Sales Tax and Product Return Guidelines