Higher Octane Gasoline

[Frye]

Assuming our bikes have one or more "knock sensors" could the increased mileage most experience with higher octane fuel be caused by the knock sensors adjusting our ignition timing when using lower octane fuel?

[2wheelsforme]

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[Frye]

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Yeah I know. Call me Mr. Obvious.

[indadman]

Yeah I know. Call me Mr. Obvious.

That would be "Captain Obvious!" But aren't we all.

Earlly next Thursday, I am heading from Dallas to Gallup, NM. Will be staying in a hotel on Route 66. Then on to Phoenix to visit an old football teammate. I'm not excited at all!

[Frye]

Assuming our bikes have one or more "knock sensors" could the increased mileage most experience with higher octane fuel be caused by the knock sensors adjusting our ignition timing when using lower octane fuel?

So if this is the case, then it's entirely possible/probable that higher octane gas which doesn't trigger the knock sensor does indeed produce more HP and/or torque than lower octane fuel? Again, this may be obvious but since there seems to be a lot of debate concerning better performance with higher octane fuel I thought it best to spell it out.

[Az Wingrider]

Back in the '50s major oil companies ran ad campaigns promoting the amazing benefits of high octane gasoline. I doubt they ever dreamed those ads would create myths that would last for generations. Even the story about the 100 MPG carburetor oil companies paid to keep a secret eventually faded away.

Pure gasoline has roughly 114,000 BTUs per gallon. E10 has a few thousand less. If an engine is running properly on fuel with enough octane to prevent detonation, it is physically impossible for a higher octane fuel with the same energy content to somehow 'find' additional horsepower.

Maybe we need to think about it this way. A modern engine is designed to generate a certain amount of horsepower. If you feed it crappy gas, the engine management computer will detune the engine to prevent damage, resulting in less horsepower. When you switch back to fuel the engine was designed for, the engine will run optimally, and you'll 'get back' the power you lost with the crappy gas.

This post from F6Dave is correct. Our bikes are designed to run on 86 octane gas and higher octane does nothing to improve power or mileage. If running higher octane gas makes you feel better that's fine but the F6B doesn't require it. I will continue riding with regular unleaded of at least 86 octane as I have with this bike and five previous Honda GLs.

Az Wingrider

[Johnharris]

An engine with a higher combustion head will develop more power then an engine with low combustion of the same size. Hi octane fuel is used only to keep from pre ignition and the added power is only because of the higher compression not the fuel octane. During WW II the p-51 mustang had quite a bit more power (hp) then the ME 109 even though the 109 had larger displacement. The P 51 Had a higher compression engine and had to run on 150 grade fuel while the 109 used 87 because of the inability of Germany to manufacture better fuels. High octane fuel actually have a higher ignition point. I try to use ethanol free fuels because I live right on the coast and it help avoids absorbing moisture into the tank.

[bob109]

This post from F6Dave is correct. Our bikes are designed to run on 86 octane gas and higher octane does nothing to improve power or mileage. If running higher octane gas makes you feel better that's fine but the F6B doesn't require it. I will continue riding with regular unleaded of at least 86 octane as I have with this bike and five previous Honda GLs.

Az Wingrider

Mother Honda designed and built a marvelous machine in the F6B! They continuously apply the KISS Method to their Engine Technology (except for changing the air filter)! They provide the initial 36k warranty and recommend 86/87 Octane fuel! Why folks insist they know more than the manufacturer has always puzzled me! If you feel higher octane is necessary for "your machine" then go for it! I personally prefer to stop at just about any "high volume gas station" fill my tank and ride on! Life is too short to split hairs on octane