Amsoil Performance Improver


We’ve all heard the stories. In fact, we’ve all been there. You were driving in heavy traffic with a hot sun beating down. You were stuck behind a truck crawling uphill and spotted a tiny opening in the next lane and made your move. But your car’s get up and go got up and left, and you crawled up the hill no faster than the truck you wanted to pass. You ask what happened?

Your  knock sensor kicked in. More than half the cars sold in the U.S. are equipped with knock sensors, which retard timing when gasoline octane isn’t high enough to allow the engine to perform the task it has been asked to perform, such as passing, going uphill or motoring in high temperatures. Retarding ignition timing protects the engine from knock. Most drivers are used to hearing the ping of knock, but not used to recognizing knock as the drop in power, responsiveness and performance that comes with knock sensors.  

The knock sensor adjusts timing before ping occurs. What can you do to protect your engine from knock and maintain the power and performance you want? At first glance, you might think the answer would be higher octane fuel. It may improve performance. But it may also be an unnecessary drain on your pocketbook. If your engine knock is caused by fuel system deposits, higher octane fuel will not solve the problem. Octane defines a gasoline’s ignition point in a perfect world, with low octane gasoline igniting at lower temperatures and pressure than high octane gasolines do. But in the real world, deposits create hot spots that cause gasoline—of even the highest octane—to ignite prematurely and knock. Intake valve deposits soak up gasoline like sponges, and the heat of compression causes the deposits to ignite the fuel before the controlled flame touched off by the spark plug reaches it. 

But wait a minute. Isn’t gasoline treated with detergents to control fuel system deposits? It sure is. But only at a treat-level that controls severe driveability problems, not garden variety knock. In  fact, deposits begin forming immediately even with refnery-treated gasoline. The only way to combat them is with additional gasoline treatment. That’s why you  need AMSOIL Performance Improver Gasoline Additive. Performance Improver (PI) inhibits the tendency of gasoline to form fuel system deposits.

How does PI work? PI keeps the entire fuel system clean, from fuel injectors or carburetors to combustion chambers. Clean injectors and carburetors deliver a full load of gasoline in a fine spray. Uniform, small droplets of spray help fuel burn completely, which improves performance. The full load of gasoline also keeps the gasoline-air ratio from becoming too lean. A too-lean mixture contains too much air for the amount of gasoline available. When combustion occurs in an environment with too much air, the combustion event is hotter than it would be in an environment without excess air. High temperatures encourage knock. Finally, a clean combustion chamber contains no knock-provoking hot-spots. And here’s a bonus. The more readily and fully gasoline combusts, the lower the vehicle’s exhaust emissions and the better its fuel economy. Many grateful PI users have written to say that PI helped them pass emissions tests, saving them money on fines and repairs.