It should be used in cars that are designed to perform better with high octane gasoline. Approximately 45 percent of new cars sold in the United States since 1990 have engines that are equipped with a device called a knock sensor. A knock sensor is designed to detect knock, often before the driver does, and adjust engine operation to avoid the knock. The adjustments made can reduce power and acceleration under certain driving conditions, especially while attempting to pass another vehicle.
All cars accumulate some combustion chamber deposits as they grow older.
Many other oil companies use a deposit control additive that actually contributes to the formation of combustion chamber deposits. Excessive combustion chamber deposits can cause an engine to require a higher octane fuel to avoid knocking or knock sensor adjustments. Combustion chamber deposits can also contribute to annoying and embarrassing run-on, especially in older, carbureted vehicles. Carburetor and fuel injector deposits can cause hesitation and stumbling on acceleration, lower fuel economy, and lower power output. Intake valve deposits can cause many of the same problems, but generally have a smaller impact on fuel economy.