IIRC premium unleaded will stay the same (E5), so use that if you want. These bikes should be fine running on it without issue - it's (E10) been in the US for a while.

If you're storing the bike for a while (over a month) either fill up the tank with E5, or add some stabiliser to a tank of E10 to prevent any separation.

 

So I take it that premium is going to be around after they phase out the ordinary stuff then.
Just cost a bit more.

 

Its not being phased out as such, just being made a bit more environmentally friendly! Premium will stay untouched as far as i am aware (for now), and to be fair on a bike the extra cost is only pennies per tank.

 

Our BMW engines run perfectly well on E10 petrol. I am using E10 for a few years now. No problems whatsoever, even not after 3 - 4 months stand still with E10 in the tank. It is recommended to fill up completely before long storage periods ( over 1 month).
Separation is not the problem, so stabilizers are not necessary.

 

This is not a BMW engine. The engines were developed with Bombardier/Rotax and were manufactured, assembled and delivered to BMW as a finished unit by Rotax. Rotax still sells these, if you're interested in starting your own bike brand with this engine.

 

So what is the general consensus, is E10 suitable for these Rotax engines?

 

The general consensus is that E10 has been in the states for over a decade, it's fine.

 

Not only did my 800ST run fine on E10, cus that's all we have, but I ran 87 octane and had no issues. My 2008 owners manual may have suggested premium but stated that one could use a lesser grade but MIGHT have less power and mileage. I never lacked power and got great mileage.

 

Mine knocks if I get rowdy on 87 AKI but not on 89.

No unusual problem with E10. Just the usual sensitivity to water. Fundamentally "ethanol treatments" are snake oil. Made of more of the same sort of thing as ethanol and do nothing but increase the ability to suspend water in solution when water is the problem in the first place.

Pure gasoline can carry very very little water in solution so it puddles at the bottom where it can be decanted. The problem is how ethanol suspends this water in solution to carry it into the engine to make it run poorly. Plus the water promotes corrosion.

 

N4, I used to get 85 octane in Colorado. Good stuff at that altitude. Even got the best mileage with 85 octane running from Salida to Crested Butte and back, 72 mpg.
Even my 1100 RT-P ran like a champ on 85 in Colorado. I got 62 mpg on one trip.
Maybe Colorado is just a bitchin' place to ride?

 

High altitude lowers octane rating requirement. That is why you can buy 85 AKI.

Here, I ride 400-1800' MSL, usually in the 700-1000' range.

87 AKI E10 is up to $2.699/gallon here.