Should the Haval Big Dog Use 95 or 92 Octane Gasoline?
2 Answers
According to the official vehicle manual recommendation, the Haval Big Dog should use 92 octane gasoline. In addition to checking the suitable gasoline grade in the vehicle manual, you can also find it indicated on the fuel tank cap of the Haval Big Dog. Generally, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should choose 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should opt for 95 octane gasoline. However, with the application of new technologies, the gasoline grade cannot be solely determined by the compression ratio. High compression ratio engines can also be tuned to use lower octane gasoline because, apart from the compression ratio, other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline octane number, the higher the octane value and the better the anti-knock performance. 92 octane gasoline contains 92% isooctane and 8% n-heptane, while 95 octane gasoline contains 95% isooctane and 5% n-heptane. If the Haval Big Dog occasionally uses the wrong gasoline grade, simply switch back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles recommended to use lower octane gasoline, using higher octane gasoline will not cause damage, but the increase in octane value will alter the fuel's ignition point, leading to delayed combustion in the engine. This means both the engine's power output and thermal efficiency will decrease, resulting in poorer performance in practical feedback. For vehicles recommended to use higher octane gasoline, using lower octane gasoline can cause engine knocking. Due to the significantly lower octane value, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If combustion occurs before the spark plug ignites during the compression stroke, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If the knocking is imperceptible, it only increases noise without obvious damage to the engine. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.
As a budget-conscious average car owner, I usually drive my Haval Big Dog to work, and using 92-octane gasoline is perfectly sufficient and cost-effective. The engine's compression ratio isn't high, and it's designed to be compatible with 92-octane fuel, so there's no risk of knocking or damage. While 95-octane fuel has a slightly higher octane rating and theoretically offers marginally better power response, the price difference is significant. With current fuel price fluctuations, I've done the math—saving a few hundred yuan a month can cover several extra fill-ups. The manual recommends 92-octane or higher, and for the base model, 92-octane works just fine. The engine runs smoothly, and fuel consumption stays around 8-9 L/100km. Unless you frequently drive on mountain roads or carry heavy loads, there's really no need to spend extra on 95-octane. My experience is that for daily commuting, 92-octane offers the best value. Even after several years, the car remains in great condition. Just remember to check the owner's manual to confirm the recommended grade before refueling.
