Because there are different types of fuels containing different octane and different chemicals, mostly the same.
There are, around, not just Taiwan, 89,92,95,95+, 98 and 98+.
It always depends on your vehicles engine, some run better on one, some don’t. Like you aren’t goo g to put 98 in a 16 year old vehicle, so t make a difference, engine not designed to handle that much, and you aren’t going to put 92 in a brand new car, probably won’t even start.
The best are always the +, or ultimate, or something the company has added on the end of the name. Like shell, 98 ultimate vs BP 98, the shell is going to be better for high performance, where BP is for high performance also but may lack an ingredient that shell has put in.
Also depends on where the fuel comes from, I usually use a CPC for my scooter around the corner, 95, does the job. I used a CPC the other day that’s about 10 minutes away and could feel the difference, in the acooter and the wallet, it was noticbly more responsive and my was a good 20nt cheaper. 20 is nothing, specially since a full tank only costs 80, bit still.
I’ve ridden motorcycles all my life, on road from a zx2r up to a gsxr 1000 and a cx500 custom built race bike. I, and most other riders can feel the difference In the fuel we use. It’s harder with an older scooter but I can feel it, my little 2000 125cc yammy goes hard! (After the work and imported parts that is ha)