Should Mitsubishi Eclipse Cross use 92 or 95 octane gasoline?

[DeKing]

Mitsubishi Eclipse Cross should use 92 octane gasoline, as this fuel grade is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, the Mitsubishi Eclipse Cross also indicates the recommended fuel on the fuel tank cap. You can usually determine the suitable gasoline grade based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95 octane gasoline. Higher compression ratios may require 98 octane gasoline. However, with the application of new technologies, the compression ratio alone cannot determine the required gasoline grade, as high-compression engines can also be tuned to use lower-octane fuel. Factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. 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. If you occasionally use the wrong gasoline grade in the Mitsubishi Eclipse Cross, simply switch back to the correct grade after refueling. However, long-term use of the wrong gasoline grade can have the following effects: Using a higher octane fuel in a vehicle designed for lower octane will not cause damage, but the increased octane rating may alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using a lower octane fuel in a vehicle designed for higher octane can cause engine knocking. The significantly lower octane rating lowers the fuel's ignition point, causing premature combustion during the compression stroke. If the fuel ignites before the spark plug fires, it creates resistance during the upward stroke. This resistance leads to unstable engine operation. Mild knocking may only increase noise without noticeable engine damage, but severe knocking indicates critical engine conditions, affecting driving stability and causing abnormal wear on pistons and cylinders, potentially leading to engine seizure.

[StMadeline]

I've been driving the Mitsubishi Eclipse Cross for over two years and have always been torn between using 92 or 95 octane gasoline. From my experience, the Eclipse Cross's official manual recommends using unleaded gasoline with an octane rating of 92 or higher, so 92 octane is completely sufficient for smooth and stable daily driving. Initially, I used 92 octane for a few months without major power issues, but there were occasional slight noises in city traffic jams. Later, I tried 95 octane for a few months, and the engine noise reduced, acceleration became smoother, and I felt the extra cost was worth it. In the long run, 92 octane is cheaper and more economical, saving me dozens of dollars on fuel each month. However, if you frequently drive on highways or pursue ultimate quietness, 95 octane offers more peace of mind. Don't forget to check the fuel cap label to ensure you don't mix different octane ratings, which could harm the engine.