89 octane
Road Captain
Joined: Nov 2012
Posts: 649
Likes: 22
From: Lakeland FL
well I do know that non ethanol fuel has more energy per gallon so you will get better mileage and it would probably do ok.
also its not any cheaper around here we have 90 octane ethanol free fuel and its cost more per gall than 93 octane w/ethanol. but as stated mileage will increase.
also its not any cheaper around here we have 90 octane ethanol free fuel and its cost more per gall than 93 octane w/ethanol. but as stated mileage will increase.
I started running the 90 octane ethanol free last summer. So far, I'm very pleased with it. It's a few cents more per gallon, so it adds 15 cents to a fill up. The only problem is planning my long distance rides around availability. I don't think it would hurt anything to run an occaisional tankfull
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Stage II
Joined: Apr 2014
Posts: 2
Likes: 0
From: Rockwall,TX
Normally, a 9.5 to 1 motor (10 to 1 on water cooled rushmores) wants 86/87 octane gas, so not sure why harley is specifying 91 octane in the owners manual for the 103's. Gas suppliers mix local supplies based on altitude and expected temperatures, so right now the middle grades is always 89 in my area, and that's what I would use if you want to follow the suggested octane recommended by manufacturer. But if a middle grade weren't available, I would go low before I would go high with 93 octane, which is formulated for an 11 to 1 motor.
Dealers sold 93 octane as "premium" for so long, that some ill-informed folks will continue to use it believing that their ride deserves the best. But the plain fact is, that all three commonly sold mixes contain the same package of ingredients, and the octane number is just a measure of how fast the gas ignites, with lower octanes igniting faster. A gas that ignites too quickly will knock in a high compression motor, and a gas that ignites too slowly will not burn completely in a lower compression motor.
So, the combination of compression and ignition advance determines what will work best, not marketing.
Dealers sold 93 octane as "premium" for so long, that some ill-informed folks will continue to use it believing that their ride deserves the best. But the plain fact is, that all three commonly sold mixes contain the same package of ingredients, and the octane number is just a measure of how fast the gas ignites, with lower octanes igniting faster. A gas that ignites too quickly will knock in a high compression motor, and a gas that ignites too slowly will not burn completely in a lower compression motor.
So, the combination of compression and ignition advance determines what will work best, not marketing.
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Tourer
Joined: Nov 2013
Posts: 339
Likes: 0
From: Olive Branch, MS
Specs call for 91 octane. In my area, 93 is what most gas stations have. I do occasionally fill with 89 if I'm filling at or near the half tank mark.
As for the original question, the thing you need to look at is the octane rating. Whether it has ethanol or not, the octane rating is the octane rating.
jt
As for the original question, the thing you need to look at is the octane rating. Whether it has ethanol or not, the octane rating is the octane rating.
jt
Been running 93 when I can get it, but 91 seems to be more available. Not really used to the HO 103 yet, to see how she runs on diffent grades, but my 11 Ultra with the 96 CID ran like crap with less than 91 for the most part. On the Sturgis run I did last August with 6 other bikes, tho, there were spots out in the corn belt states that ONLY had 87 Ethanol free available. Nothing else. The 96 fully loaded ran like a champ & my mpg increased to better than 50. With the corn added I would average about 42 mpg