Should the Excelle use 92 or 95 octane gasoline?
2 Answers
According to the official vehicle manual recommendation, the Excelle 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. Typically, 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 use 92 octane gasoline, while those with a compression ratio between 10.0-11.5 should use 95 octane gasoline. However, with the application of some new technologies nowadays, the gasoline grade cannot be solely determined by the compression ratio. Engines with high compression ratios can also be tuned to use lower-octane gasoline because, besides 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 Excelle 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 by mistake 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 practice. For vehicles recommended to use higher-octane gasoline, using lower-octane gasoline can cause engine knocking. Due to the significantly lower octane value, the reduced ignition point may cause the gasoline to ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires, resistance will be generated during the upward stroke. This resistance can make the engine run very unstably. If the knocking is imperceptible, it may only increase noise without obvious damage to the engine. However, noticeable knocking indicates severe engine conditions, affecting not only driving stability but also causing abnormal wear to pistons and cylinders, and in severe cases, even cylinder scoring.
I've been driving the Excelle for a while and am used to using 92-octane gasoline, mainly because it's more economical and practical. My car is the 1.5L naturally aspirated version, and according to the manufacturer's manual, 92-octane gasoline fully meets the requirements—no need to go for higher octane ratings. Using 92-octane is fine for daily driving; the engine runs smoothly, and fuel consumption stays stable at around 7.5 liters per 100 km. Some people might feel a slightly quicker response with 95-octane, but the Excelle's design doesn't have a high compression ratio. Over time, using 95-octane could be a waste of money and might even cause minor issues due to fuel mixing in the tank. I recommend checking your car's fuel cap or manual first—the recommended octane rating marked there is the safest bet. 92-octane gas stations are easy to find everywhere, making refueling convenient, even on long trips. In short, for the basic Excelle model, there's no need to complicate things—sticking with 92-octane is both economical and reliable, and the money saved can buy you a few cups of coffee.
