Octane rating
Tourer
Joined: Oct 2007
Posts: 394
Likes: 29
From: Georgia
BT:
You said, "It is much like a light switch. The light switch turns the electricity on and off, it doesn't care if the bulb is burned out or not."
If the bulb is no good, and no circuit is being completed, then no electricity is being used. You can have every single light switch in your house in the ON position, but if your bulbs are bad, the NO ELECTRICITY IS BEING USED. That's the way I've understood it. Just thought I'd chime in. Perhaps somebody else already said it.
Ben
You said, "It is much like a light switch. The light switch turns the electricity on and off, it doesn't care if the bulb is burned out or not."
If the bulb is no good, and no circuit is being completed, then no electricity is being used. You can have every single light switch in your house in the ON position, but if your bulbs are bad, the NO ELECTRICITY IS BEING USED. That's the way I've understood it. Just thought I'd chime in. Perhaps somebody else already said it.
Ben
Presuming an honest rating, 93 octane is 93 octane no matter the corn content. The viscosity of 20-50 dino oil should be the same as 20-50 synthetic again presuming an honest rating.
Where you may be getting confused is that 90 octane pure gas can get a higher octane rating with ethanol mixed in, but so can a mix of 90 and 95 octane pure gas be rated above 90 based on the proportion of the mix. Either your machine can tolerate 90 octane (regardless of corn content) or it can't. I have found mine is tolerant of mid grade where I live so that is what I use. I am fortunate to still have pure gas as an option. The only time mine gets corn is on a trip when there is no option.
"Tune" is timing and mixture set into the computer which can be adjusted slightly by O2 sensors, temp, atmospheric pressure. The grade of gas you use will not change the data load in the computer so there is no "ruining" your tune. If you get poor enough gas, there may be damage to the hardware of the engine caused by pinging, detonation, and deposits. If it is severe enough or lasts long enough it can crack pistons, burn holes in them, damage bearings, foul spark plugs BUT it won't ruin your tune. If your O2 sensors get fouled, they will no longer provide data to the computer to optimize the current situation, but again, the basic data load will remain unchanged.
The computer has a control function with very little feed back, though there is some. It is much like a light switch. The light switch turns the electricity on and off, it doesn't care if the bulb is burned out or not. The "tune" of the light switch doesn't change based on the condition of the light bulb.
Where you may be getting confused is that 90 octane pure gas can get a higher octane rating with ethanol mixed in, but so can a mix of 90 and 95 octane pure gas be rated above 90 based on the proportion of the mix. Either your machine can tolerate 90 octane (regardless of corn content) or it can't. I have found mine is tolerant of mid grade where I live so that is what I use. I am fortunate to still have pure gas as an option. The only time mine gets corn is on a trip when there is no option.
"Tune" is timing and mixture set into the computer which can be adjusted slightly by O2 sensors, temp, atmospheric pressure. The grade of gas you use will not change the data load in the computer so there is no "ruining" your tune. If you get poor enough gas, there may be damage to the hardware of the engine caused by pinging, detonation, and deposits. If it is severe enough or lasts long enough it can crack pistons, burn holes in them, damage bearings, foul spark plugs BUT it won't ruin your tune. If your O2 sensors get fouled, they will no longer provide data to the computer to optimize the current situation, but again, the basic data load will remain unchanged.
The computer has a control function with very little feed back, though there is some. It is much like a light switch. The light switch turns the electricity on and off, it doesn't care if the bulb is burned out or not. The "tune" of the light switch doesn't change based on the condition of the light bulb.
Grand HDF Member
Joined: Sep 2013
Posts: 3,820
Likes: 587
From: Michigan
That aside, an engine that is designed (higher compression ratio) to take advantage of higher octane fuel will tend to be more efficient (more power per combustion cycle) than one capable of running on anything you can feed it.
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
Thanks to a few qualified replies it would seem that octane rating and fuel chemistry is well beyond average comprehension. How exactly can a consumer get reasonably educated on such a complex topic that impacts our daily lives? I use a much less technical method of fuel selection, use the lowest octane that doesn't ping, doesn't require intimate knowledge of the scientific methods used to define a cryptic rating that apparently doesn't mean squat when the mixology is factored.
Seasoned HDF Member
Joined: Sep 2009
Posts: 17,145
Likes: 6,168
From: SE Michigan
Here in Michigan, we get 89 or 93. I choose 93.
Outstanding HDF Member
Joined: Aug 2011
Posts: 2,325
Likes: 7
From: SE Illinois
There are MANY benefits to using ethanol and/or higher ethanol blends!
There is just so much bad information out there it's unbelievable & most of the people bashing ethanol just don't have a clue what they're talking about.
I'm not even going to get started this time 'cause I could type 5 pages of factual info & it's just not worth it on a Friday afternoon to get into a fuel debate.
If HD would design bikes to be flex fuel & capable of running on higher ethanol blends & even E-85, emissions would be so much cleaner and pipe emissions would have so much less NOx that we wouldn't need all this emissions crap on our bikes, such as catalytic converters, lean AFRs, new water cooled heads, etc. Engines also make more power running on higher ethanol blends, especially E-85.
Cleaner emissions, less emission controls would be needed, engines making more power using a much cheaper fuel. Yeah, those sound like good reasons for people to hate ethanol....good grief.
& to think....all it would take is replacing a few hoses & gaskets & tank liner with alcohol compatible materials such as Teflon & using different programming in the ECM. The automakers do it...so could HD & we would all benefit greatly, regardless of what the haters think they know.
& before someone starts bashing my opinions, you don't have to agree with what I have to say...that's ok, I know the facts.
& yes, I work in the fuel industry & have for almost 17 years...on both sides. I know my **** & I'll leave it at that.
Good day.
Last edited by Sharkman73; Oct 11, 2013 at 02:10 PM.
Road Warrior
Joined: Jul 2009
Posts: 1,979
Likes: 2
From: Northern Colorado
ThereThere is no benefit in running a higher octane than what's recommended, and the need for octane decreases as you go up in altitude. In your case I would be running 89. JMO
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Seasoned HDF Member
Joined: Sep 2009
Posts: 17,145
Likes: 6,168
From: SE Michigan
So THATS why I cant get higher than 91 northwest of the Mississippi (or at least anywhere from Minnesota on the way to Sturgis).