What type of gasoline should the Hongqi H9 use?
2 Answers
The Hongqi H9 should use 95-octane gasoline, as recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, you can also find this information on the fuel tank cap, which will indicate the recommended grade. Typically, the gasoline grade can also be determined based on the engine's compression ratio. Vehicles with a 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. If the compression ratio is higher, 98-octane gasoline is recommended. However, with the use of new technologies, the compression ratio alone cannot determine the appropriate gasoline grade. High compression ratio engines can also be tuned to use lower-octane gasoline, as other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, the higher the gasoline octane rating, 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 Hongqi H9 occasionally uses the wrong gasoline grade, simply switch back to the correct grade after the current tank is used up. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles designed for lower-octane gasoline, using a higher-octane grade will not cause damage, but the increased octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces both the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles designed for higher-octane gasoline, using a lower-octane grade can cause engine knocking. The significantly lower octane number reduces the fuel's ignition point, causing premature ignition during the compression stroke. If combustion occurs before the spark plug fires, resistance is generated during the upward stroke, making the engine run very unevenly. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine issues. The vibrations not only affect driving stability but can also cause abnormal wear on the pistons and cylinders, potentially leading to cylinder scoring in severe cases.
I've specifically studied the fuel requirements for the Hongqi H9. Its manual clearly states that it must use 95-octane or higher gasoline. This car's 2.0T turbocharged engine has a high compression ratio, and using 92-octane fuel can easily cause knocking. Last time, my neighbor tried to save money by filling up with 92-octane, which resulted in the engine warning light coming on and reduced power output. I recommend choosing 95-octane from reputable gas stations - 98-octane is even better but significantly more expensive. Remember not to wait until the fuel light comes on to refuel; top up when the tank is down to a quarter to avoid fuel pump overheating. Nowadays, China VI emission standard vehicles have stricter fuel requirements - using the wrong fuel causing engine problems may void the dealership warranty.
