Should the Haval M6 use 92 or 95 octane gasoline?

[VincentRose]

The Haval M6 can use 92 octane gasoline. This octane rating is recommended in the vehicle's official user manual. In addition to checking the appropriate gasoline grade in the user manual, the Haval M6 also indicates it on the fuel tank cap. You can usually determine the suitable gasoline grade 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. For higher compression ratios, 98 octane gasoline is recommended. However, with the application of new technologies, the compression ratio alone cannot determine the gasoline grade, as high-compression engines can also be tuned to use lower-octane gasoline. 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 Haval M6 occasionally uses the wrong gasoline grade, simply switch back to the correct grade after use. However, long-term use of the wrong gasoline grade can have the following effects: For vehicles designed for lower octane gasoline, using higher octane gasoline will not cause damage, but the increased octane number may alter the fuel's ignition point, leading to delayed combustion in the engine. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. For vehicles designed for higher octane gasoline, using lower octane gasoline can cause engine knocking. Due to the significantly lower octane number, the gasoline may ignite prematurely during the compression stroke. If combustion occurs before the spark plug fires, resistance will develop during the upward stroke. This resistance makes the engine run very unstably. Mild knocking may only increase noise without significant engine damage, but severe knocking indicates serious engine issues, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring.

[VanElias]

I previously checked the fuel cap and user manual of the Haval M6, which clearly stated that it is recommended to use 92-octane gasoline, i.e., regular unleaded gasoline. Personally, I've been driving this car for over three years, always filling it with 92-octane, and the fuel consumption has remained stable at around 8 liters per 100 km. I feel the power is sufficient for daily commuting and city driving, making it very worry-free. Using 95-octane might slightly improve engine response on some mountain roads or highways due to its higher octane rating reducing knock, but honestly, the difference is negligible. It just adds an extra hundred or so yuan to the monthly fuel cost, which really isn't worth it. I once accidentally filled up with 95-octane at a gas station and couldn't tell the difference while driving unless you're a professional racer pushing it on a track. In summary, sticking to the manufacturer's recommendation is the safest bet—there's no need to spend extra money chasing so-called 'premium fuel.' Regular attention to car maintenance, such as checking the air filter and spark plugs periodically, will keep the M6 running smoothly and economically.

[SanJameson]

From an automotive engineering perspective, the 1.5T engine of the Haval M6 was originally designed to be compatible with 92-octane gasoline, with its anti-knock parameter around 93 perfectly matching standard fuel requirements. While using 95-octane gasoline with its higher octane rating of 95 can optimize combustion efficiency and prevent minor knocking under extreme conditions like long uphill climbs, it only improves power output by less than 1% in daily use, making it a waste of cost. I conducted a week-long test comparing 92 and 95 octane in city driving, and the average fuel consumption and acceleration times were nearly identical. Unless you live in high-altitude areas and frequently go off-roading, upgrading the fuel grade is completely unnecessary. The fuel system can adapt to different octane ratings, but prolonged use of 95-octane may increase carbon deposit accumulation, reducing long-term reliability. It is recommended to stick with 92-octane to maintain original performance, perform a few cold starts and warm-ups each week, and ensure a longer engine lifespan.

[Sá]

Simply put, the Haval M6 just needs 92-octane gasoline, as clearly stated in the manual. Using 95-octane won't make much difference—it's purely a waste of money unless you're burning cash for psychological comfort. I've tested it on several round trips between two cities, and the fuel consumption and acceleration were basically the same—don't bother messing around. Just stick with 92-octane for daily use; it's sufficient even for highway driving. The engine is tuned this way, so don't get tricked by gas station promotions into spending unnecessary money.