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Gasoline _ Octane Rating_ Ethanol

Good info to provide Steve. It mirrors much of what a Shell Engineer had shared with me a few years ago.
As the author says, there is so much misinformation on the internet that it is actually more difficult than it should be to sort fact from fiction in many cases.
 
It has to do with the detergents they put in their gasoline and whether or not they participate in the program. I know the Costco stations I go to have this large tank of detergents on site near their pumps. Sam's and Murphy may not see it benefiting them much to go through the process to be certified.

If you read "Sach" in BMW Roundel magazine, he is a Shell-or-nothing devotee. But for better than a decade, when at home, I've been buying gas at SAMS Club ($1.86/gal for regular today, 10% ethanol - didn't catch the price for premium) and have never had a fuel-related problem with my BMWs - auto or bike. My thinking is they sell so much gas - they receive deliveries 4X a day - it's always "fresh" and as none of my vehicles ever sit for more than 24 hrs, at most the gas in them is one or two weeks "old." But living in NM, with low relative humidity most of the year, water migrating into the gas is not a big issue. When I lived in tropical New Orleans - well, that was different. :)
 
If you read "Sach" in BMW Roundel magazine, he is a Shell-or-nothing devotee. But for better than a decade, when at home, I've been buying gas at SAMS Club ($1.86/gal for regular today, 10% ethanol - didn't catch the price for premium) and have never had a fuel-related problem with my BMWs - auto or bike. My thinking is they sell so much gas - they receive deliveries 4X a day - it's always "fresh" and as none of my vehicles ever sit for more than 24 hrs, at most the gas in them is one or two weeks "old." But living in NM, with low relative humidity most of the year, water migrating into the gas is not a big issue. When I lived in tropical New Orleans - well, that was different. :)

2 years ago on a vacation around harrison in Arkansas I had this experience. I will burn 91 octane no alcohol when I can get it. I filled in Eureka Springs and ran on down to Harrison Ar where I filled again with 91 no alcohol I did notice the gas had a different scent. I reserved my motel room but it was not available so I did not unload my panniers. I the proceeded to enjoy the local roads, riding like I always do when enjoying the local roads I was at 220 miles when I fueled, and it took less fuel than normal. Quick check of the mileage was 46 MPG. I normally have to be at 5000 feet + to get anywhere near that. Filled up again, checked in. Next day, same experience except without the panniers on I was getting 48. Next day filled up again in Harrison set out to the east. 48 again. Then I filled up on the road somewhere, and noted the gas smelled like it does at home. Like a switch was flipped, 44, normal without the panniers. Bike ran the same, just used more fuel. Filled up in Harrison that night, next day was getting 48 again. Every tank of the different smelling stuff I got better mileage. Heading home, when I refueled in Eureka, my mileage started going down again. All times was advertised no alcohol fuel, there is truth in advertising, right????

Of course it my observation, not scientific at all. I may try to go back this summer and see if the repeats.

I have no explanation.

Rod
 
When I worked for a living, we had to deal with measuring Jet A aviation fuel quantity (lbs/kgs) very accurately...for obvious reasons. FWIW many large airlines buy their fuel by energy content, not volume or mass. It the energy in the fuel that moves the plane.This is because fuel across the world differ substantially while still meeting the Jet A specification. If my memory is correct the energy content per weight could vary by nearly 25% depending on the source across the world. Also the looks and order varies widely too.

Not sure how much this applies to the gas we buy...but a bit of trivia for amusement.
 
Just because there is no alcohol in your gasoline does not mean the additive packages from each brand is the same. The gasoline coming out of the refinery cracking tower is all the same, but what leaves the refinery in the delivery tankers might be very different depending on the additive package of the brand, added after refining but pre delivery. Just because it is gasoline, and it burns in your bike, doesn't mean it is all good gasoline that your bike will like.

Friedle
 
What I’m waiting to read is a post of an article that divulges how suppliers of lead-free gasoline are able to obtain high octane.

In the old days this required an additive, which was tetraethyl lead. MTBE was a later solution. Both are now illegal and the only legal additive that I’m aware of is ... ethanol.

Anyone know how they do it?
 
Except that what is "best" in Colorado is not the best in the Kalahari. And what is best in Minnesota in January may not be best in Arizona in July. And as a global seller BMW cannot possibly know what might be best in Angola or Italy vs California, where in each case rules, made by politicians and not internet gurus, are changing. What BMW says is a compromise, and they are not as omnicient as you think, Kent. Better than most internet gurus for sure - "Motor is their Middle Name" - but not perfect by a long shot. We all need to think, not just read something and proceed. Thinking is required.

Anti seize on spines? Yeek!

Air is the same everywhere, although of course altitude can vary ... a subject BMW could easily cover. In the USA, oil companies adjust fuel locally for altitude, but if the spec from BMW is for premium, premium at any location is still the requirement. The same bike will have the same octane requirement everywhere. Pump labeling protocols may of course vary by country, but the bike’s requirements will not.
 
Air is the same everywhere, although of course altitude can vary ... a subject BMW could easily cover. In the USA, oil companies adjust fuel locally for altitude, but if the spec from BMW is for premium, premium at any location is still the requirement. The same bike will have the same octane requirement everywhere. Pump labeling protocols may of course vary by country, but the bike’s requirements will not.

Except they do. Check out what is supposed to happen in foriegn countries when the quality varies.
 
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....depending on the elevation at which the motorcycle is ridden. i.e. Higher elevation = lower octane requirement.

Understand this and previously noted in USA gasoline distributors already provide lower octane at higher elevation locations. Don't think this means substitute regular for premium however.

Of course even Airheads with CV carbs adjusted fueling for altitude, today's fuel injection is even better at that. Not so much for bikes yet, but today's more commonly turbocharged cars will not be eligible for lower octane at altitude. Think basically it's a truism that is going away.
 
I'm surprised no one has mentioned Wes Fleming's article "Understanding octane: AKI, MON, and RON, oh my!" in the February issue of BMW ON.

Wes points out that higher compression requires higher octane.
 
I'm surprised no one has mentioned Wes Fleming's article "Understanding octane: AKI, MON, and RON, oh my!" in the February issue of BMW ON.

Wes points out that higher compression requires higher octane.

Wes writes some good articles.
 
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Understand this and previously noted in USA gasoline distributors already provide lower octane at higher elevation locations. Don't think this means substitute regular for premium however.

Depending on altitude and original octane requirement, that's exactly what I mean.

Your desire to be contrary in all things sometimes clouds your ability to understand facts or concepts which may disagree with your original thought processes. Just an observation. :D
 
Wes points out that higher compression requires higher octane.

A lot is dependant on cylinder head design. As an example, a buddy of mine had an R90S in 1979 and I had a Honda CBX. Both bikes had similar compression ratios. His bike had issues running on premium fuel (after the lead additive was removed) whereas my Honda ran well on regular fuel. I know more than a few folks converted their bikes to dual plugs in order to get them to run properly. A newer ZX-10R with a compression ration of 13:1 will happily run on 89 octane. But, all else being equal, Wes would be correct.
 
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Depending on altitude and original octane requirement, that's exactly what I mean.

Your desire to be contrary in all things sometimes clouds your ability to understand facts or concepts which may disagree with your original thought processes. Just an observation. :D

:thumb
 
I have an R1150R that I can only describe as "fussy" regarding its fuel. It usually ran great but sometimes seemed to indicate it needed a tuneup for no apparent mileage reason.

We were visiting friends and riding the southern Ohio curvy roads waiting to head to Vintage Days when I concluded it really seriously needed a tuneup. But we stopped at a fuel station, and while still in the parking lot I could detect a difference, and within a mile or two the tune up was no longer indicated.

That bike ran well with some fuel and crappy with other fuel of the same brand and the same octane. Those folks who claim gas is gas should come meet my R1150. :banghead
 
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