gasoline
Seasoned HDF Member
Joined: Apr 2017
Posts: 9,603
Likes: 20,703
From: Globe AZ
I have no need for the expense of 100+ octane to get rid of the ethanol. At the rate I use fuel (about a tank a week) there is literally no impact on the bike. the fuel doesnt sit in it long enough to collect a meaningful amount of water (not that our humidity here is high enough for it to collect any....)
Extreme HDF Member
Joined: Dec 2007
Posts: 13,402
Likes: 941
From: Illinois
OP. Could please explain how a slow burning high octane gas can out perform 87 octane which burns more complete?
You do know that octane is simply a measure of the fuels burn rate and not a power rating. All gasoline is 115,000 btu's. BTU's is power. So the slower the burn rate the less power developed during the power stroke. And the more unburned gas goes out the exhaust pipe.
But that info is beyond some of the folks on here pay grade.
I have had 30 H-D's since 2006 from 883, 1200, 1250 cc's and 88 through 120 Cu In motors and have put 400K on them combined all with E10 87 octane and they run strong.
My 120's are 10.5:1, the 1250 is 12:1 as is the Street Rod and the 110's range from 9.5:1 to 10.12:1.
Here is some thing for those "pure" folks. The E10 gas is the same cost to produce as straight gas yet because of marketing "pure" bs the sheep flock in and pay about $0.30 to much for it.
Motogp specs alcohol for its Sunoco race fuel because it acts as a refrigerant cooling the incoming charge to be denser to assist more power during the power stroke. So much for the "pure" BS.
But that does go out the window at 15% and higher mixtures.
You do know that octane is simply a measure of the fuels burn rate and not a power rating. All gasoline is 115,000 btu's. BTU's is power. So the slower the burn rate the less power developed during the power stroke. And the more unburned gas goes out the exhaust pipe.
But that info is beyond some of the folks on here pay grade.
I have had 30 H-D's since 2006 from 883, 1200, 1250 cc's and 88 through 120 Cu In motors and have put 400K on them combined all with E10 87 octane and they run strong.
My 120's are 10.5:1, the 1250 is 12:1 as is the Street Rod and the 110's range from 9.5:1 to 10.12:1.
Here is some thing for those "pure" folks. The E10 gas is the same cost to produce as straight gas yet because of marketing "pure" bs the sheep flock in and pay about $0.30 to much for it.
Motogp specs alcohol for its Sunoco race fuel because it acts as a refrigerant cooling the incoming charge to be denser to assist more power during the power stroke. So much for the "pure" BS.
But that does go out the window at 15% and higher mixtures.
Last edited by lh4x4; Jun 3, 2017 at 09:19 PM.
Club Member
Joined: Mar 2016
Posts: 11,687
Likes: 22,234
From: Clearwater, Idaho
OP. Could please explain how a slow burning high octane gas can out perform 87 octane which burns more complete?
You do know that octane is simply a measure of the fuels burn rate and not a power rating. All gasoline is 115,000 btu's. BTU's is power. So the slower the burn rate the less power developed during the power stroke. And the more unburned gas goes out the exhaust pipe.
You do know that octane is simply a measure of the fuels burn rate and not a power rating. All gasoline is 115,000 btu's. BTU's is power. So the slower the burn rate the less power developed during the power stroke. And the more unburned gas goes out the exhaust pipe.
Not sure what pay grade has to do with anything here....
Seems like we've been through this before..........
Ultimate HDF Member
Joined: Dec 2010
Posts: 7,776
Likes: 2,252
From: wet coast BC
Shifting up to higher octane
MIT study finds wider use of premium gas could save fuel, money.
http://news.mit.edu/2014/premium-gas...uel-money-1028
MIT study finds wider use of premium gas could save fuel, money. http://news.mit.edu/2014/premium-gas...uel-money-1028
Seasoned HDF Member
Joined: Apr 2010
Posts: 33,717
Likes: 3,723
From: Connecticut.
NO!NO.NO.NO.NO.NO.NO.NO and btw, uh NO! the higher octane will drain your wallet.....if the bike doesn't perform with the recommended octane something is wrong,tune,plugs,wires,.......it is not the fuel. unless you got a tanful of shitty fuel...but the octane is not your issue
.
octane has everything to do with the burn rate...high compression motors require a fuel to burn at the top of the piston cycle// 87 fuel ignites well before the piston reaches top of the cycle....(dieseling) igniting from compression before the spark. compression equals heat heat equals ignition .....get a grip people. higher octanes have a lesser combustion rate hence the reason it is recommended for all high performance motor., btw if the motor has a shitload of wear...nothing will matter; the motor will run just fine with any fuel.
.octane has everything to do with the burn rate...high compression motors require a fuel to burn at the top of the piston cycle// 87 fuel ignites well before the piston reaches top of the cycle....(dieseling) igniting from compression before the spark. compression equals heat heat equals ignition .....get a grip people. higher octanes have a lesser combustion rate hence the reason it is recommended for all high performance motor., btw if the motor has a shitload of wear...nothing will matter; the motor will run just fine with any fuel.
Last edited by ChickinOnaChain; Jun 4, 2017 at 08:49 AM.
Seasoned HDF Member
Joined: Apr 2013
Posts: 32,851
Likes: 17,887
From: Newcastle, OK
Road Warrior
Joined: Sep 2016
Posts: 1,385
Likes: 1,416
From: Northern NJ
The octane rating is a measure of the products ability to resist premature ignition due to compression, period.
It has nothing, absolutely nothing to due with:
- burn rate
- kindling temperature of the fuel (the spark is more than hot enough to lite all commercial gasoline quickly)
- power per gallon (BTU)
- temperature of the burn
- Detergent levels in the product (some brands may load 91, but it is not done universally or even predominantly.)
Last edited by hairymoth; Jun 4, 2017 at 06:12 AM.
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Road Warrior
Joined: May 2013
Posts: 1,462
Likes: 105
From: Kentucky
I run all octane's in my Ultra from reg to prem. Your engine will let you know what it will run on, really do you know what you are actually getting? I ride mine, it's for transportation, doesn't get polished and waxed before every ride. I don't dress up in a Harley outfit. Sorry got off topic. It's just gas !!
Tourer
Joined: Jul 2016
Posts: 480
Likes: 349
From: Wilmington, NC
You may run fine on regular if you don't run up hills or get on your bike. It will sound fine but that don't mean you're not damaging your engine; carbon build up etc. For the few bucks you save a week on gas, wait until you have to tear your engine down. They recommend premium for a reason, they don't just sit and throw darts at a board with octane numbers on them. Another mistake is running ethanol free gas. If you are running regular without ethanol you're really building up the carbon. Ethanol burns hotter than gas and burns off carbon. That's why cars 50 years ago had to be de-carboned and modern ones do not. There is no reason to run non-ethanol gas in any modern engine, except for boats (which sit on the water and the ethanol will absorb water). You're riding a bike that was made by folks that have built bikes for 100 years. They aren't trying to screw you. Don't turn riding a bike into a ****ing science project. You'll be the one on the board next month with a thread: "Harley's are crap! I just sucked a piston with only 10 k miles!"