What happens if you fill 95 octane gasoline with 92 octane?
1 Answers
Occasionally filling 95 octane gasoline with 92 octane won't cause immediate harm, but long-term use can affect the lifespan of the car's ignition system, fuel injectors, and spark plugs, leading to engine cylinder scoring and advancing the vehicle's major repair schedule. You can determine the appropriate gasoline grade based on the engine's compression ratio. Cars with an engine compression ratio between 8.6-9.9 should use 92 octane gasoline, while those between 10.0-11.5 should use 95 octane. For higher compression ratios, 98 octane is recommended. However, with the application of new technologies, the compression ratio alone cannot dictate the gasoline grade. High compression ratio engines can be tuned to use lower octane gasoline due to other influencing factors such as ignition timing, turbocharging technology, and Atkinson cycle technology. Generally, higher gasoline grades have higher octane ratings and better anti-knock properties. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. Occasionally using the wrong gasoline grade only requires switching back to the correct grade after consumption. However, long-term use of the wrong grade can have the following effects: For vehicles designed for lower octane gasoline, using higher octane gasoline won't cause damage, but the increased octane rating can alter the fuel's ignition point, leading to delayed combustion. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles designed for higher octane gasoline, using lower octane gasoline can cause engine knocking. The significantly lower octane rating reduces the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is created during the upward stroke. This resistance makes the engine run very unstably. Mild knocking only increases noise without significant engine damage, but severe knocking indicates serious engine conditions, affecting driving stability and causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring. Considerations when selecting gasoline: Choose gasoline with appropriate volatility based on the ambient temperature. Gasoline with good volatility ensures easy cold starts and balanced engine warm-up. However, excessive volatility can cause vapor lock in fuel lines, preventing the fuel pump from functioning properly and leading to engine stalling. Select gasoline based on lead content.