I agree with most that you don't need higher octane unless your motor is pinging and that's what I've always believed until 2 weeks ago when I was at the track. The pumps went down at the track and I was out of gas. So one of the guys let me fill up with his gas which was 91/110 VP mix. The next time out I swear the bike rev'd quicker. Well I finished that tank and went back to 91 (lowest they have at the track) and ran it the rest of the day. Before the last session I decided to put in a little more gas to make sure I didn't run out so I added about 1.5 of the VP110 and again I swear the bike rev'd quicker. So I don't know what to say cause I don't think it was in my head. I did about 60 laps in 2 days and now where my shift points are and what gear to be in and with the VP I was having to add an extra shift in because I was hitting redline. So now I don't know what to believe. My bike has the following:

02 F4I trackbike
- full arrow exhaust
- PCIII with custom map
- K&N filter
- And all the bolt ons...clipons, rearsets, etc....

 

about the only way to know for sure is to dyno it.

 

I agree. Like I said, I always thought that it wouldn't make a difference unless the motor was built to run on it. But I swear that bike rev'd quicker.

 

I used up the last of my 94 and filled up with 87 yesterday.

I haven't noticed any difference, so i'm sticking with 87.

 

I have noticed the manual says 87 but underneath the seat its say 91+

 

Legal reasons?
I'm going to verify that. I don't recall seeing a sticker underneath my seat.

 

What if you had the bike dyno tuned with 93+?

I had my bike tuned on a Factory pro braking dyno, with a 4 gas anylizer, and it was mapped not on a graph or curve, but by gas readings and O2 levels and all that in the exhaust, so if it is tuned and the mixture is such that 93+ is burning properly, will dropping to 89 throw things off?

 

Possibly, if it was tuned so lean that the extra resistance to detonation was required.

 

i'll give 87 a try once this tank of gas runs out