
GLC uses fuel with an octane rating of 95, and the fuel tank capacity is 66L. The fuel tank opening is located on the right rear side of the vehicle. Precautions for refueling the Mercedes-Benz GLC: During the refueling process, all personnel should try not to stay in the vehicle; if staying inside, the doors must be closed. Also, all electronic devices should be turned off during refueling to avoid causing fires or even more serious disasters. Never make phone calls or smoke at the gas station, as these actions can easily lead to explosion accidents. How to open the fuel tank cap: The Mercedes-Benz GLC does not have a fuel tank button switch. Simply press the fuel tank cap when the vehicle is unlocked to open it, then unscrew the inner cap to refuel. To close, reverse these steps.

















Having driven the GLC for several years, I've found that it's best suited for 95 or 98 octane gasoline, with 98 being the ideal choice. This model uses a high-compression ratio engine, and using lower octane fuel like 92 can easily cause knocking—that sudden engine shudder you feel while driving. Over time, this can damage engine components. I once tried using 92 octane in an emergency. While the car didn't break down, acceleration was slower and fuel consumption increased. Since then, I've stuck with 98 octane, finding the performance more stable and fuel economy easier to manage. By the way, the manual clearly states the recommended octane rating, and occasionally using higher octane fuel can even help clean carbon deposits. In short, using the right fuel is key to protecting your car.

I'm a car enthusiast and have studied the powertrain of the GLC, which is designed to match the octane requirements of 95 or 98 gasoline. Using higher octane like 98 can reduce the risk of knocking, making the engine run smoother; using lower octane such as 92 is fine for short trips, but frequent use can lead to severe carbon buildup, affecting turbocharging performance. Personally, I prefer 98 octane because it improves acceleration response, delivering powerful driving dynamics. Also, make sure to fill up at reputable gas stations and avoid low-price traps. After all, maintaining the engine well ensures the car lasts longer.

We use a GLC for commuting and picking up the kids, always opting for 98-octane gasoline. The manual states that both 95 and 98-octane are acceptable, but higher octane is recommended for safety. While 92-octane is cheaper, we rarely use it as it may cause engine knocking, especially during hot weather. Experience has taught us not to prioritize saving money on fuel—once when I tried 92-octane, I noticed slight abnormal noises and promptly switched back to higher octane. Protecting the engine can save you from costly repairs.

From a technical perspective, the GLC's engine requires high-octane fuel to prevent pre-ignition issues, making 95 or 98 octane the ideal choices. Using lower-grade fuel like 92 octane may cause knocking during high-load operation, leading to vibrations and wear. I always use 98 octane as it keeps the engine clean and improves efficiency. Additionally, higher-octane fuel can reduce exhaust emissions, benefiting the environment. Occasionally using lower-grade fuel in emergencies is acceptable, but it's important to revert to the recommended grade as soon as possible.

When using the GLC, I've developed a habit of filling it with 98-octane gasoline, while the manual recommends 95 or 98 as preferred. Using higher-octane fuel protects the engine, reduces knocking and carbon buildup; using lower-octane fuel like 92 is acceptable in emergencies but can damage components over time. From my personal experience, the car runs smoother and has slightly better fuel efficiency with 98-octane. It's advisable to regularly check the fuel cap label or manual to ensure the correct fuel is used. During travels, using 92-octane is also fine, but switch back to higher-octane fuel immediately upon returning.


