What octane fuel you using?

[flynrider]

So, yesterday, I rode 450 miles (along the Ilinois River Rd. from Chicago to south of Peoria. Nice ride, but I digress). I've been an "87 is fine" guy for this bike since I purchased it 5000 miles ago. On a whim, I started using 93 on this trip. I figure I had about half the trip with 93 and half with some blend of 87 and 93. There are far too many variables to list, so it is impossible to tell for sure that octane had anything to do with my impressions, but I did feel that acceleration, particularly when starting in 2nd gear, improved. I did not check fuel consumption. I am not suggesting that anyone buy higher octane to improve performance, but I am going to toy around with 93 and 89 octane for awhile and see if what I think I felt was something other than my imagination.

I used 87 after few thousands on 91, when i switch back to 91, I perceived it got more power and the engine response was better. since then I used 91.

The bike can run on 87, but more octane, more power. it is the laws of physics. All expensive sport cars recommend 91

The notion that octane = power probably comes from the same "physics" dictionary that says turbo = faster.

Octane is an anti-knock index. If your engine isn't detonating with 87, it isn't going to run any better with a higher anti-knock number. Expensive sports cars use 91 because their high compression engines will detonate with lower octane.

Some more sophisticated car engines will retard the timing if it's knock sensors detect detonation (which means you probably fueled up with a lower than recommended octane). It that case, it will produce more power with a higher octane. As far as I can tell, there are no knock-sensors built into the CB11 engine and the compression ratios are not high enough to warrant using higher octane to prevent detonation.