Wethead Fuel requirements - Premium gas only?

After riding Harleys for years I find it humorous to come to a BMW group and see the same discussions! Tires, oil, and premium fuel. I have yet to own a motorcycle that does not recommend premium. On the other hand I will run what ever I can find and not worry about it one bit. Our wet heads will run fine on regular, with a slight reduction in performance. Nothing to get your panties all waded up about. If you are actually going to ride cross country and in some of the less inhabited parts of the country you will not be able to find premium, so run what ever you can find.

I remember rolling into a small town with a couple other motorcycles. We needed gas badly. The first gas station had only regular and one of the riders refused to use it because he just knew he needed premium or his engine would certainly blow up. We ventured all over that small town and hit the 4-5 gas stations and not one had it. I thought he was going to have a heart attack as he pumped regular into his Harley. It would have been funny if I had not been there.

pauleknight said:

got 20K miles on my GSA running 99% regular unleaded.

No problems and the bike works like a charm.

I get anywhere between 39-42MPG depending on speed and/or headwind

I have gotten as high as 45 once but normally it is closer to 40

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Pretty much the same. I actually get better mileage with regular gas, and have run it on all my BMWs from my R1100RS, to 3 R1200 Hexheads and my 2015 R1200GS.

Jim

PS People can run what they want, but this has been my personal experience.

Just to add some very specific clarity on one point that has been lost.

AKI (Anti-Knock Index) is what is posted on gas pumps in the United States. I believe it is derived as Motor Octane plus Research Octane divided by 2, ie the average of MON and RON. Almost everywhere "Regular" is shown as AKI 86 or 87 (sometimes 85 at high altitudes). "Mid-Grade" is almost always shown as AKI 89. Premium is often either AKI 91 or 93.

The manual quoted in post # 2 specifies AKI 89. (This might vary by year. I don't know.) In the United States that is mid-grade. So use what you wish but MON and RON and ROZ are obsolete numbers not referred to on fuel pumps in the U.S.A. anymore, if they ever were. I was very happy to see BMW Rider's Manuals now referencing AKI as the specified octane index. MON, RON, ROZ just con't compute on US fuel pumps. RON (Research Octane) is used in the EU. In other countries YMMV - I have no clue.

It does vary by year. My 2015 GSA uses 89 AKI. My friend's 2018 GSA uses 87 AKI, as spelled out in each of our Rider's Manuals.

Some of the confusion may come from the wording in the manual:

For my 2015 R1200GS LC "Super unleaded (max 10% ethanol, E10) 89 AKI..."

89 AKI is mid-grade, but "Super" sounds like premium...

For winter storage, I filled up with AKI 91 ethanol-free...(or was it AKI 93?)

So 89 AKI it is for normal situations.

Harry

AKsuited said:

Some of the confusion may come from the wording in the manual:

For my 2015 R1200GS LC "Super unleaded (max 10% ethanol, E10) 89 AKI..."

89 AKI is mid-grade, but "Super" sounds like premium...

For winter storage, I filled up with AKI 91 ethanol-free...(or was it AKI 93?)

So 89 AKI it is for normal situations.

Harry

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A lot of people get hung up on the label.
I only look at the AKI number.