Is it mandatory to use 95-octane gasoline for the Hongqi HS5?
3 Answers
The Hongqi HS5 must use 95-octane gasoline, as this fuel grade is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, you can also find it indicated on the fuel tank cap of the Hongqi HS5. 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. If the compression ratio is even higher, 98-octane gasoline is recommended. However, with the application of new technologies, the compression ratio alone cannot determine the appropriate gasoline grade, as high compression ratio engines can also be tuned to use lower-octane gasoline. This is because factors other than compression ratio, 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 HS5 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 recommended to use lower-octane gasoline, using a higher-octane grade will not cause damage, but the increase in octane number can alter the fuel's ignition point, leading to delayed combustion in the engine. This results in reduced engine power and thermal efficiency, manifesting as poorer performance in actual driving experience. For vehicles recommended to use higher-octane gasoline, using a lower-octane grade can cause engine knocking. This is because the significantly lower octane number reduces the gasoline's ignition point, causing it to ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires during the compression stroke, resistance will be encountered during the upward stroke. This resistance makes the engine run very unstably. If the knocking is mild, 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 on pistons and cylinders, and in severe cases, cylinder scoring.
I've been driving the Hongqi HS5 for a while now, and it really should use 95-octane fuel. The engine of this Hongqi model is finely tuned with a high compression ratio. Using 92-octane fuel can easily cause knocking or pre-ignition, which over time can damage the pistons, reduce power, and lower fuel efficiency. I've heard from experienced drivers that occasionally using 92-octane might be okay, but long-term use can lead to increased carbon deposits, louder engine noise, and more expensive repairs. From a safety perspective, a breakdown on the highway can be very dangerous, and the warranty for a new car might become void. It's advisable to always check the fuel grade when refueling. 95-octane is slightly more expensive, but it's worth it for engine protection. Additionally, air quality is also affected, as higher-octane fuel burns cleaner. In short, a well-running car is the best way to save money.
When I first got my Hongqi HS5, I also wondered if I could save some money by using 92-octane gasoline. After consulting a mechanic, he advised strictly following the manufacturer's recommendation to use 95-octane, as the engine is designed for high performance. Lower-octane fuel could lead to incomplete combustion and actually increase fuel consumption. I tried using 92-octane once and felt the acceleration was sluggish, plus I worried about damaging the engine. From a practical standpoint, the monthly difference in fuel costs is just a few dozen yuan, but if the engine develops issues, minor repairs could cost hundreds and major repairs thousands—definitely not worth it. I always pay attention to the fuel grade label now; 95-octane is more stable and offers lower long-term maintenance costs. These days, I only use 95-octane and enjoy driving with peace of mind.
