Should Haval Big Dog Use 92 or 95 Octane Gasoline?
2 Answers
According to the official vehicle manual recommendation, Haval Big Dog should use 92 octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual, you can also find it marked on the fuel tank cap. Generally, the gasoline grade can also be determined by the engine's compression ratio. Vehicles with an engine compression ratio between 8.6-9.9 should use 92 octane gasoline, those between 10.0-11.5 should use 95 octane gasoline, and if the compression ratio is higher, 98 octane gasoline should be used. However, with the application of some new technologies nowadays, the gasoline grade cannot be solely determined by the compression ratio. A high compression ratio 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 grade, the higher the octane number 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 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 low-grade gasoline, using higher-grade gasoline will not cause damage, but the increase in octane number 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 as experienced. For vehicles recommended to use high-grade gasoline, using lower-grade gasoline can cause engine knocking. Because the octane number is too low, the lowered ignition point of the gasoline may cause premature ignition during the compression stroke. If detonation occurs before the spark plug fires during the compression stroke, resistance will arise during the upward stroke. This resistance can make the engine run very unstably. If it's mild knocking, it only increases noise without significant damage to the engine. However, if noticeable knocking occurs, it indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, and in severe cases, cylinder scoring.
I've been driving a Haval Big Dog for two years, using 92-octane gasoline, and the engine has been running smoothly. The engine design of this Haval model is reasonable—92 octane isn't high but is sufficient, especially for daily commuting. Knocking is an engine combustion phenomenon, and using higher-octane fuel like 95 can reduce it but at a higher cost. The manual recommends 92 octane, particularly for the 1.5T version. When refueling, I choose reputable gas stations to avoid poor-quality fuel from smaller stations affecting performance. It's economical—a full tank of 92 saves tens of yuan, adding up over time. I suggest new car owners first check the manual and follow the instructions—no need to overcomplicate things. Long-term observation shows minimal engine noise, stable fuel consumption, and a hassle-free, cost-effective experience.
