Should the UY125 use 92 or 95 octane?
2 Answers
UY125 has a compression ratio of 10.3:1 with a relatively low engine speed, so it should use 95 octane gasoline. Reference for gasoline grade selection: The main difference between different grades of gasoline lies in their anti-knock performance, which is an important indicator for measuring fuel quality. Typically, it is directly related to the octane rating of the gasoline. Higher-grade gasoline has better anti-knock performance during combustion, reducing engine vibration. The primary reference for determining the appropriate gasoline grade for an engine is the compression ratio. Generally, engines with a compression ratio exceeding 10.1:1 should use 95 octane gasoline. Precautions for refueling: Do not arbitrarily switch to a lower-grade gasoline. If a lower-grade gasoline is used, it may cause premature combustion, leading to engine knocking. Additionally, incomplete combustion of the gasoline can result in increased carbon deposits, clogging the fuel lines and injectors, as well as causing reduced vehicle power and increased fuel consumption.
After riding motorcycles for so many years, I think the UY125 runs just fine on 92 octane fuel. The manual recommends 92 octane gasoline, and 95 octane is much more expensive without necessarily being better for the bike. The 125cc engine doesn't have a very high compression ratio, so 92 octane is enough to prevent knocking—no need to go for higher octane. I usually fill up with 92 for my daily commute—it's cost-effective and reliable, saving me dozens of dollars a month, which means a few extra trips. If you use 95, you might feel like the performance is better psychologically, but in reality, there's no noticeable difference in engine response. I suggest checking the manual to confirm and getting into the habit of regularly inspecting the spark plugs—this ensures safety and extends the bike's lifespan. In short, don't waste money; save where you can. Riding should be about practicality.
