Is 91octane really needed
Road Master
Joined: Jul 2006
Posts: 762
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From:
RE: Is 91octane really needed
For what it's worth. I run the PCIII fuel unit tuned for Harley Touring.
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I have always ran 91 (no ethanol) or 92 (no \\;ethanol)  \\;in my 96" 2007 Road Glide. \\; \\; Last week I for the first time, put in 91 octane with 10% ethanol to try it, with about 1/2 gallon left in the tank. Pinging under load, at wide open throttle started within 15 miles. I ran the tank \\;to about 1/2 gallon left just the other day. Put in 91 (NO ethanol) and the pinging is pretty much gone now.
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I have always ran 91 (no ethanol) or 92 (no \\;ethanol)  \\;in my 96" 2007 Road Glide. \\; \\; Last week I for the first time, put in 91 octane with 10% ethanol to try it, with about 1/2 gallon left in the tank. Pinging under load, at wide open throttle started within 15 miles. I ran the tank \\;to about 1/2 gallon left just the other day. Put in 91 (NO ethanol) and the pinging is pretty much gone now.
Road Warrior
Joined: Sep 2007
Posts: 1,314
Likes: 5
RE: Is 91octane really needed
I always run the best grade available, which around here is usually 91, but also usually with 10% ethanol. Whether we like it or not I think at least a 10% mix is going to become almost universal, it has been around here for over 10 years. I would never consider saving a single dollar on a fill up by running the low grade, its just plain stupid in my mind given how much I spent on the bike to risk damaging it for a 1 dollar savings per tank (premium is only 20 cents more expeinsive than regular, and I almost never have to put more than 5 gallons in at a fill).
Advanced
Joined: Apr 2008
Posts: 95
Likes: 2
From: Libertyville, IL
RE: Is 91octane really needed
ORIGINAL: Scootr
There are as many opinions on this as there are about oil. \\; I use whats recomended for my engine. \\; The difference really isn't much. \\; .02
There are as many opinions on this as there are about oil. \\; I use whats recomended for my engine. \\; The difference really isn't much. \\; .02
Agree.
Tourer
Joined: Jan 2008
Posts: 272
Likes: 0
From: NE Ohio
RE: Is 91octane really needed
Surprised the crap out of me too Probably more dependent on whose premium you buy but when you travel you cant always choose Next tank is back to mid grade to see what happens
Road Captain
Joined: May 2008
Posts: 516
Likes: 1
From: New Hampster!
RE: Is 91octane really needed
I am thinking you must have gotten some bad gas (other than the ethanol) Ethanol has a higher octane rating and therefore is more resistant to detonation. Problem with Ethanol \\;is it has an affinity to water and will pull the moisture out of the air in the tank and cause phase separation, this is where the ethanol has absorbed as much water vapor as it can hold and actually drops out of suspention with the gas and settles to the bottom of the tank leaving a layer of low octane gas. \\;
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A higher octane value in itself will give you no power or mileage gain. A higher octain value will allow you to increase your timing or increase your compression and that will give you a power gain but just adding the fuel without any tuning will do nothing. A higher octain fuel actually burns slower. \\;However if your engine is \\;tuned to run with a certain octain value \\;then you use a higher value you will gain no benefit other than \\;increased resistance to detonation/preignition. A higher value 93,103 does not contain more power, just more resistance to detonation.
Federal regulation requires all gasoline sold for on road use to have 10% ethanol in it by some date this year (I cant remember the date). And as far as gas goes it is all the same. To a certain extent....It all comes of the ship at the port and goes into the same tanks and then as the trucks fill the addative packages are added based on the brand. (Dad used to haul gas from the ports here on the east coast!)
Peace Out
Still need to work on my sig
 \\;
08 Ultra 110 Anniv.
Rinehart
SERT
[sm=usa.gif]Son in US Army Infantry
2-25 SBCT Taji Iraq[sm=patriot.gif]
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A higher octane value in itself will give you no power or mileage gain. A higher octain value will allow you to increase your timing or increase your compression and that will give you a power gain but just adding the fuel without any tuning will do nothing. A higher octain fuel actually burns slower. \\;However if your engine is \\;tuned to run with a certain octain value \\;then you use a higher value you will gain no benefit other than \\;increased resistance to detonation/preignition. A higher value 93,103 does not contain more power, just more resistance to detonation.
Federal regulation requires all gasoline sold for on road use to have 10% ethanol in it by some date this year (I cant remember the date). And as far as gas goes it is all the same. To a certain extent....It all comes of the ship at the port and goes into the same tanks and then as the trucks fill the addative packages are added based on the brand. (Dad used to haul gas from the ports here on the east coast!)
Peace Out
Still need to work on my sig
 \\;
08 Ultra 110 Anniv.
Rinehart
SERT
[sm=usa.gif]Son in US Army Infantry
2-25 SBCT Taji Iraq[sm=patriot.gif]
 \\;
 \\;
Elite HDF Member
Joined: Jan 2006
Posts: 4,388
Likes: 0
From: Dallas,Texas
RE: Is 91octane really needed
ORIGINAL: leohd
most pumps use the same hose with 3 selections so your 1st gallon is probably what the last person used anyway.
most pumps use the same hose with 3 selections so your 1st gallon is probably what the last person used anyway.
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So I guess i'm getting a gallon of deisel every time I fill up. Cause the pumps at the station also have diesel. If some one bought diesel just before me. I don't think so.
Road Captain
Joined: May 2008
Posts: 516
Likes: 1
From: New Hampster!
RE: Is 91octane really needed
Other Dude,
 \\;actually its a 08 Ultra with a 110 kit and the anniversary ed. my bad!
 \\;actually its a 08 Ultra with a 110 kit and the anniversary ed. my bad!
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Road Captain
Joined: May 2008
Posts: 516
Likes: 1
From: New Hampster!
RE: Is 91octane really needed
[blockquote]quote:
ORIGINAL: leohd
most pumps use the same hose with 3 selections so your 1st gallon is probably what the last person used anyway.
[/blockquote]
 \\;\\\\\\;
 \\;\\\\\\;
So I guess i'm getting a gallon of deisel every time I fill up. Cause the pumps at the station also have diesel. If some one bought diesel just before me. I don't think so.
 \\;
Not exactly, You will note that the pumps that provide diesel have a sepaerate hose and nozzle for diesel and another for the multiple grades of gas.
ORIGINAL: leohd
most pumps use the same hose with 3 selections so your 1st gallon is probably what the last person used anyway.
[/blockquote]
 \\;\\\\\\;
 \\;\\\\\\;
So I guess i'm getting a gallon of deisel every time I fill up. Cause the pumps at the station also have diesel. If some one bought diesel just before me. I don't think so.
 \\;
Not exactly, You will note that the pumps that provide diesel have a sepaerate hose and nozzle for diesel and another for the multiple grades of gas.
Stellar HDF Member
Joined: Apr 2008
Posts: 2,131
Likes: 651
From: Gettysburg, PA (For Now)
RE: Is 91octane really needed
ORIGINAL: VINNIE JAMES
dispatch...is the 103 unleaded or does it have lead? thanks,vinnie
dispatch...is the 103 unleaded or does it have lead? thanks,vinnie
It's unleaded. You can't buy leaded gasoline anymore. It also doesn't have Ethanol in it either. \\;It's a bit different then gasoline you get from your local station. It's gasoline in it's most purest form. The only higher octane fuel you can get over it is avation fuel. \\;