Does mixing No. 92 and No. 95 gasoline have any impact?
1 Answers
Mixing No. 92 and No. 95 gasoline does have an impact. Occasionally using the wrong gasoline grade only requires switching back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can lead to the following effects: For vehicles designed for lower-grade gasoline, accidentally using higher-grade gasoline won't cause damage, but the increased octane rating alters the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, manifesting as poorer performance in actual driving experience. For vehicles designed for higher-grade gasoline, using lower-grade gasoline can cause engine knocking. The significantly lower octane rating reduces the gasoline's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance builds up during the upward stroke. This resistance makes the engine run very unevenly. Mild knocking may only increase noise without obvious engine damage, but noticeable knocking indicates severe engine conditions. The vibrations not only affect driving stability but also cause abnormal wear on pistons and cylinders, potentially leading to cylinder scoring in severe cases. Besides checking the recommended gasoline grade in the vehicle's manual, you can also find it marked on the fuel tank cap. Typically, the gasoline grade can be determined by the engine's compression ratio: vehicles with compression ratios between 8.6-9.9 should use No. 92 gasoline, while those with ratios between 10.0-11.5 should use No. 95 gasoline. However, with modern technologies, compression ratio alone isn't the sole determinant. High compression ratio engines can be tuned to use lower-grade gasoline due to other influencing factors like ignition timing, turbocharging technology, and Atkinson cycle technology. Generally, higher gasoline grades have higher octane ratings and better anti-knock properties. No. 92 gasoline contains 92% isooctane and 8% n-heptane, while No. 95 gasoline contains 95% isooctane and 5% n-heptane.
