High octane fuel
Tourer
Joined: Jun 2007
Posts: 297
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From:
RE: High octane fuel
Actually it's the other way around. The higher your octane rating the hotter it has to be to ignite which is what makes it better for high compression motors. So, with the hotter running 07's it'd make sense that higher octane fuels would result in a better running motor since you're less likely to suffer from premature ignition of the fuel in the cylinder (compression detonation, just like diesel).
I'm not a physicist or a chemist but Wiki has a pretty good write up here:
http://en.wikipedia.org/wiki/Octane_rating
In particular the "Effects of Octane Rating" section covers this topic...
"Octane rating has no direct impact on the deflagration (burn) of the air/fuel mixture in the combustion chamber. Other properties of gasoline and engine design account for the manner at which deflagration takes place. In other words, the flame speed of a normally ignited mixture is not directly connected to octane rating. Deflagration is the type of combustion that constitues the normal burn. Detonation is a different type of combustion and this is to be avoided in spark ignited gasoline engines. Octane rating is a measure of detonation resistance, not deflagration characteristics. It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion). However, premium grades of petrol often contain more energy per litre due to the composition of the fuel as well as increased octane."
I'm not a physicist or a chemist but Wiki has a pretty good write up here:
http://en.wikipedia.org/wiki/Octane_rating
In particular the "Effects of Octane Rating" section covers this topic...
"Octane rating has no direct impact on the deflagration (burn) of the air/fuel mixture in the combustion chamber. Other properties of gasoline and engine design account for the manner at which deflagration takes place. In other words, the flame speed of a normally ignited mixture is not directly connected to octane rating. Deflagration is the type of combustion that constitues the normal burn. Detonation is a different type of combustion and this is to be avoided in spark ignited gasoline engines. Octane rating is a measure of detonation resistance, not deflagration characteristics. It might seem odd that fuels with higher octane ratings explode less easily, yet are popularly thought of as more powerful. The misunderstanding is caused by confusing the ability of the fuel to resist compression detonation as opposed to the ability of the fuel to burn (combustion). However, premium grades of petrol often contain more energy per litre due to the composition of the fuel as well as increased octane."
Road Captain
Joined: Feb 2006
Posts: 573
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From:
RE: High octane fuel
Always have run 93. I think Derexor is right though. I've read that many times over but have never really seen a difference in my HI Comp motors. They ping no matter what. I've had to add some boost to get the knock to go away. How's that work?
Road Master
Joined: Nov 2006
Posts: 1,164
Likes: 401
From: Port Coquitlam B.C.
RE: High octane fuel
I thought it was the other way around too but I wasn't sure. Either way the timing of the bike needs to be adjusted to compensate for the different burn time or the bike will loose power.
RE: High octane fuel
I stick to the highest octane available. I figure that the added price is no big deal as a bike gets great gas mileage. Now if I was to put high octane in my 13mpg truck, I would probably be broke.
Road Captain
Joined: May 2007
Posts: 596
Likes: 7
From: Illinois
RE: High octane fuel
Dealer had cheap gas in my bike when I picked it up. It knocked like crazy, until I could put some 92 in it. I have a couple cars that perform better on the cheaper stuff like 87, because the compression is'nt high enough to burn anything higher.
Outstanding HDF Member
Joined: Jun 2005
Posts: 3,238
Likes: 0
From: Desmoines, Iowa
RE: High octane fuel
i try to run 92 all i can . some times i got to go with 91.i know with one point should'nt matter but it does.i have run 94 in it and 93 cant find it that often. but when i can i will run the higher the motor just sounds better.and quieter.
Road Warrior
Joined: May 2006
Posts: 1,276
Likes: 0
From: Top of Texas
RE: High octane fuel
ORIGINAL: LeadSlinger0311
Xbox 92 is all I can get here as well .
I can go down the road to MIS (michigan speed way ) and get higher but i tend to use additives (rocket fuel )treats up to 5 gallons and you can notice a differance .
but my dealer told me when I picked up thebike to NOT use cheap gas (im lucky I like my dealer ).
the nice thing is MI is one of the higher gas prices so that makes me smile every time i fill up
(joking)
Slinger ..............out
Xbox 92 is all I can get here as well .
I can go down the road to MIS (michigan speed way ) and get higher but i tend to use additives (rocket fuel )treats up to 5 gallons and you can notice a differance .
but my dealer told me when I picked up thebike to NOT use cheap gas (im lucky I like my dealer ).
the nice thing is MI is one of the higher gas prices so that makes me smile every time i fill up
(joking)Slinger ..............out
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