What type of fuel should be used for the BJ40?

[BrooklynLee]

According to the official vehicle manual recommendations, the BJ40 2022 2.3T Automatic 4WD Excellence Edition should use 95-octane gasoline, while the 2022 2.0T Automatic 4WD Ring Tower Champion Edition and Official Edition should use 92-octane gasoline. In addition to checking the appropriate gasoline grade in the vehicle manual, the BJ40's fuel cap also indicates the recommended gasoline type. Typically, the fuel 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 new technologies, the compression ratio alone cannot determine the required gasoline grade. High-compression engines can also be tuned to use lower-octane fuel, as other factors such as ignition timing, turbocharging technology, and Atkinson cycle technology also play a role. Generally, higher-octane gasoline has a higher octane number and better anti-knock properties. 92-octane gasoline contains 92% isooctane and 8% n-heptane, while 95-octane gasoline contains 95% isooctane and 5% n-heptane. If the BJ40 occasionally uses the wrong gasoline grade, simply switching back to the correct grade after consumption is sufficient. However, prolonged use of the wrong gasoline grade can have the following effects: For vehicles designed for lower-octane fuel, using higher-octane gasoline will not cause damage, but the increased 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. For vehicles designed for higher-octane fuel, using lower-octane gasoline 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 ignites, resistance is created 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 conditions, affecting not only driving stability but also causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring in extreme cases.

[McPatrick]

My BJ40 has been running for almost three years, and I've always used 92-octane gasoline. It feels quite smooth. Both the fuel cap and the user manual suggest using 92 or 95-octane, and I choose 92 mainly to save money, especially since fuel prices aren't cheap these days. Using lower-quality fuel can easily lead to carbon buildup or engine damage. For city commuting, the power is sufficient, and it performs well on highways too. When off-roading in mountainous areas, I still use 92-octane—the engine sound remains stable, and it's very durable. Remember not to use 98-octane or anything like that; it's a waste of money with little performance improvement. Also, beware of counterfeit gas stations—stick to big brands like Sinopec or PetroChina for safety. When changing the engine oil, make sure to use the right grade and avoid mixing them up. This way, your car will last longer with fewer repairs.

[DelIvan]

I've been working on car repairs for several years. For tough off-road vehicles like the BJ40, the engine compression ratio is designed to be compatible with 92 or 95 octane gasoline. From the many cases I've handled, I recommend using 95 octane as it's better—higher octane helps resist knocking, especially when climbing steep slopes or under heavy loads. However, 92 octane is also fine; the fuel cap clearly states the recommendation, and the user manual provides more details. Don’t try to be clever by adding diesel or other substances, as this can easily damage the spark plugs or cause starting issues. The key is to use fuel from reputable gas stations—don’t cut corners by going to unreliable ones to avoid impurities clogging the fuel system. Also, check the fuel lines and filters after off-roading to extend the engine’s lifespan. This car is easy to maintain—just don’t mess around with it unnecessarily.

[EmmaFitz]

Veteran drivers remind you, don't overthink the fuel issue with the BJ40. Using 92 octane is cost-effective and durable—I even use it when driving in the desert, and the engine runs smoothly without any issues. The fuel cap clearly indicates 92 or 95 octane, so just follow that. I've tried higher octane fuel before, and there was no noticeable difference—just a waste of money. When tackling complex off-road terrain, make sure to refuel at clean gas stations and avoid using fuel with too many impurities. Save money and hassle this way.

[MariaMarie]

From an environmental perspective, it's most suitable to use 92 or 95 octane gasoline for the BJ40. The fuel tank and manual recommend this, as using lower octane fuel can reduce emissions and minimize resource waste. Personally, I suggest following the official recommendations—avoid overfilling or mixing different octane grades to ensure higher engine efficiency and lighter exhaust emissions. Additionally, considering carpooling or public transport to save fuel would be even better.

[DiBlakely]

Off-road enthusiasts tell you that filling the BJ40 with 95-octane gasoline makes it perform more smoothly on rugged roads. The fuel cap recommends 92 or 95-octane, but when tackling rocks or mud in the wild, higher octane can prevent knocking, ensuring stable and quick engine response. Avoid using regular low-octane fuel to prevent stalling. Choose reputable gas stations to fill up, reducing breakdowns on long trips.