What type of fuel should a G63 use?
2 Answers
The G63 should use 95-octane gasoline, as recommended in the vehicle's official owner's manual. In addition to checking the owner's manual for the appropriate fuel type, you can also find this information on the fuel tank cap, which typically indicates the recommended gasoline grade. Generally, the fuel type can also be determined based on the engine's compression ratio. Vehicles with a compression ratio between 8.6 and 9.9 should use 92-octane gasoline, while those with a ratio between 10.0 and 11.5 should use 95-octane gasoline. For higher compression ratios, 98-octane gasoline is recommended. However, with advancements in technology, relying solely on the compression ratio to determine fuel grade is no longer sufficient. Engines with high compression ratios can now be tuned to use lower-octane fuel due to other influencing factors such as ignition timing, turbocharging technology, and Atkinson cycle technology. Generally, higher-octane gasoline has a higher octane rating and better anti-knock properties. For example, 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 fuel grade in a G63 is not a major issue—simply switch back to the correct grade after the tank is empty. However, prolonged use of the wrong fuel can have the following consequences: Using a higher-octane fuel in a vehicle designed for lower octane will not 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 fuel 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 builds up during the upward stroke, leading to unstable engine operation. Mild knocking may only increase noise without noticeable engine damage, but severe knocking indicates serious engine issues, affecting driving stability and causing abnormal wear on pistons and cylinders—or even cylinder scoring in extreme cases.
I've been driving the AMG G63 for a while now, and fueling it is quite particular. The car officially recommends using at least 95 octane fuel, but 98 octane is preferred, as marked on the fuel cap. The G63 has a high-compression engine with powerful performance. If you try to save money by using 92 octane, the engine will experience knocking and detonation. You'll hear abnormal noises in the short term, and over time, it will wear out the pistons or cylinders. I only use 98 octane myself—acceleration is smooth and powerful, especially noticeable on highways. Fuel efficiency is also decent, with average consumption kept between 12-15L. In summer when temperatures are high, higher-octane fuel provides better anti-knock properties and more effective protection. Fuel quality matters, so I always choose reputable gas stations to avoid adulterated fuel. During regular maintenance, matching the right engine oil is also crucial. Spending a little extra upfront can save you from major repair costs later.
