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Discussion Starter · #1 · (Edited)
The Truth About Which Octane To Use

Now after much research and reading I could make this very simple, use what the manual recommends. If you own a 03 or up and the manual says to use 91octane, use 91octane. But if you are like me that just does not satisfy, you have to know why.
The simplified version is those of us whose motorcycle engines run a higher compression ratio, say 13:1 compression ratios must generally use the higher octane fuels to avoid predetonation.

Predetonation is the combustion of the fuel before we wanted it to. This is bad for the engine. Enough said on that.

From what I have read, using a higher octane than is recommended will provide no additional benefit to the engine. Unless you are purchasing over 100 octane racing fuel. Due to the fact these fuels also usually contain some form of oxygenator (TANE, MTBE, etc) which frees extra oxygen from the fuel to mix into the reaction at time of detonation. This effectively does increase the combustion pressure levels, which should result in *slight* increases in total power output -- not because of the extra predetonation or preignition protection, but specifically because of the extra oxygen coming into the equation.

These are also some other things that factor in on your octane requirements.

Altitude: Higher altitudes decrease your octane requirement.
Humidity: Drier air increases your octane requirement.
Engine spark timing: If your engine’s spark
timing is increased, your octane requirement
increases.

In the end use what the manual says to use, there is a reason it is there. Different bikes and years of the R6 have different compression ratios, therefore can use different octanes.
Just remember Octane does not equal power.

For more information visit the link below it will explain things a bit better and in way more detail.

http://www.motorcycleanchor.com/motorcycle/how_to/mc_octane.html

:drink :drink :drink :drink :drink :drink :drink :drink :drink :drink :drink
 

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R is for respect!
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1,623 Posts
good research.
 

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.............
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12,482 Posts
wow. that's exactly what I've been doing... going by the manual. It's strange that Yamaha would actually recommend an octance to use in their engines.

freaky.
 

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custom never ends
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44 Posts
If your bike is stock and you use it to comute to work than OK, but if you RIDE it, put some race fuel in it and tell me there's no diff. If there is no diff, keep it for commuting
 

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GSXR Eater
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754 Posts
well i guess im good then right cuz i run 110 octane? u said +100 is fine
 
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