What type of fuel should be used for motorcycles with a compression ratio greater than 11?

[Chloe]

You can use 97-octane gasoline. Engine compression ratio: Generally speaking, the higher the compression ratio of an engine, the smaller the volume of the combustible mixture being compressed, resulting in greater power and lower fuel consumption. However, the engine's compression ratio must be matched with another indicator, which is the gasoline's anti-knock index, also known as the octane number, or the gasoline grade. Types of fuel: Currently, the fuel market abroad offers gasoline in three grades: 93, 95, and 98. Engine compression ratios are also designed with reference to these three grades, so there are not many engines that are compatible with 90-octane gasoline.

[HaleyLee]

I've been riding motorcycles for over a decade. When the compression ratio exceeds 11:1, you must use higher-octane gasoline, such as 95 or 98 octane. High-compression engines generate extremely high temperatures and pressures during compression, and using low-octane fuel can easily cause knocking, which sounds like metal pinging, and over time can damage pistons and cylinders. In my own experience, sticking to premium fuel improves engine efficiency, delivering more power and better fuel economy. Especially during summer or long-distance rides, when temperatures rise and the risk of knocking increases, I always check the manual for the recommended fuel grade. One lesson from mistakenly using 92 octane fuel is etched in my memory: saving a little money isn't worth a major overhaul, and regular maintenance can extend your motorcycle's lifespan.

[LeRebecca]

Bro, for high-compression motorcycles, especially those with a ratio over 11, you definitely need to use 95 octane or higher. Higher octane fuel prevents knocking, which is when the fuel ignites prematurely, causing the engine to shake violently and affecting performance. Last year, I saved up and bought a bike with a 12:1 compression ratio. The manual clearly states to use 97 octane, but 95 octane works fine too—no issues in the city, but it runs noticeably smoother on the highway. Don’t cheap out with 92 octane; its lower octane rating can cause problems, and a single repair could cost hundreds, enough to cover a year’s worth of premium fuel. The risk is even higher in mountainous areas or under heavy load—knocking could lead to unexpected engine shutdown, and safety comes first. Also, stick to reliable gas stations; mixing with lower-quality fuel is too risky.

[SerenityDella]

Engines with high compression ratios generate higher temperatures during compression, and insufficient octane ratings can lead to spontaneous ignition, causing knocking. The octane rating measures a fuel's resistance to knocking, and 95-octane fuel is suitable for motorcycles with a compression ratio around 11. Using lower-octane fuel may cause the ECU to retard ignition timing to prevent knocking, but this sacrifices power. In principle, adhering to the manufacturer's recommended high-octane fuel ensures stable combustion and prevents damage to engine components like piston rings. Modified engines are more sensitive, and knocking damage is irreversible. Taking a moment to check the fuel rating can save you trouble down the road.