Should Private Cars Generally Use 92 or 95 Octane Gasoline?

[OMiguel]

Whether a private car should use 92 or 95 octane gasoline depends on the vehicle model. Compact private cars generally use 92 octane gasoline, while most mid-size joint-venture brand cars use 95 octane gasoline. The difference between 92 and 95 octane gasoline is not significant; they merely have different octane ratings, which affects their anti-knock properties. The choice should be based on the engine's compression ratio. You can refer to the vehicle's manual, which specifies the engine's compression ratio and the recommended gasoline grade. Compact cars' engines are not highly demanding, with compression ratios typically between 8.6 and 9.9. Mid-size cars have compression ratios between 10 and 11.5. If the compression ratio exceeds 11.5, higher octane gasoline may be considered—these engines are usually found in luxury brand vehicles with strong performance. Engines with compression ratios between 8.6 and 9.8 are suitable for 92 octane gasoline, while those between 10 and 11.5 are suitable for 95 octane gasoline.