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?
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.
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
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
Improver Gasoline Additive. Performance Improver (PI) inhibits the
tendency of gasoline to form fuel system deposits.
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.