Can the 2020 Hongqi H5 only use 95 gasoline?
2 Answers
According to the official vehicle manual recommendation, the 2020 Hongqi H5 should use 95-octane gasoline. In addition to checking the suitable gasoline grade in the vehicle manual for the 2020 Hongqi H5, you can also find it on the fuel tank cap, which will be clearly marked. 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 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, the gasoline grade cannot be solely determined by the compression ratio. High compression ratio engines can also be tuned to use lower-octane gasoline. This is 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 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 the 2020 Hongqi H5 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 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. For vehicles recommended to use higher-octane gasoline, using lower-octane gasoline can cause engine knocking. Due to the significantly lower octane number, the gasoline's ignition point decreases, causing premature ignition during the compression stroke. If combustion occurs before the spark plug ignites, resistance will arise during the upward stroke. This resistance makes the engine run very unstably. If it's mild knocking, 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.
Regarding the fuel selection for the 2020 Hongqi H5, I'd like to share my perspective. This vehicle's engine features a relatively high compression ratio, typically above 9.5:1, and the manufacturer's manual generally recommends using 95-octane gasoline due to its higher anti-knock properties that effectively prevent engine knocking. Knocking refers to abnormal combustion in the cylinders, which can cause noise and vibration, and prolonged use of lower-octane fuel may potentially damage pistons or spark plugs. While some drivers believe using cheaper 92-octane fuel is acceptable, I've personally observed reduced power responsiveness, particularly during highway driving or hill climbing, with possible increased fuel consumption. From a technical standpoint, 95-octane isn't strictly mandatory, but adhering to manufacturer recommendations better protects engine longevity. I suggest checking the fuel grade label on the fuel filler door before each refueling to avoid prolonged mixed usage or incorrect lower-octane fuel – this practice ensures smoother operation and reduces maintenance concerns.
