Why can't the Kaiyi C3 use 92-octane gasoline?
2 Answers
Kaiyi C3 should use 92-octane gasoline, as this fuel grade is recommended in the vehicle's official user manual. In addition to checking the appropriate fuel grade in the user manual, the Kaiyi C3 also indicates the recommended gasoline grade on the fuel tank cap. 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. For higher compression ratios, 98-octane gasoline is recommended. However, with the application of new technologies, the compression ratio alone cannot determine the appropriate fuel grade. High compression ratio engines can also be tuned to use lower-octane gasoline due to factors like ignition timing, turbocharging technology, and Atkinson cycle technology. Generally, higher gasoline grades have higher octane ratings 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. Occasionally using the wrong gasoline grade in the Kaiyi C3 only requires switching back to the correct grade after consumption. However, long-term use of the wrong gasoline grade can have the following effects: Using a higher-octane gasoline in a vehicle designed for lower octane won't cause damage, but the increased octane rating alters the fuel's ignition point, leading to delayed combustion. This reduces the engine's power output and thermal efficiency, resulting in poorer performance. Using lower-octane gasoline in a vehicle designed for higher octane can cause engine knocking. The significantly lower octane rating lowers 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. This resistance makes the engine run very unstably. Mild knocking only increases noise without significant engine damage, but severe knocking indicates serious engine conditions, affecting driving stability and causing abnormal wear on pistons and cylinders, potentially leading to cylinder scoring.
I drove a Kaiyi C3 and initially filled it with 92-octane gas to save money, but the engine made knocking sounds during acceleration, with noise as loud as drumming. Later, I checked the manual and found it requires at least 95-octane fuel because the engine has a high compression ratio. The 92-octane fuel’s low octane rating caused premature combustion, leading to knocking, which could damage pistons and valves. I recommend sticking to 95-octane fuel—otherwise, long-term use of lower-grade fuel will increase carbon buildup, spike fuel consumption, and cost thousands in repairs. Regular maintenance checks on fuel quality can prevent these issues—don’t cut corners to save a few bucks and end up costing yourself more.
