Everyone knows the evils of ethanol here is my question...

The recommended octane for my carbed XL1200C is 91 octane.
Here in South Florida I can easily get real, pure, non-ethanol gas
at 90 octane. (no higher)
Would you use 90 real gas or 91 Ethanol 10%?
p.s. ...I don't drive the bike hard.

 

Try both, then you tell us.
I run 93.

 

What is it about the manufacturer's recommendation that you don't understand?

 

You will be fine either way. I would run straight gas imo. Unless you have modified compression 90 should be plenty sufficient and still retain performance. Especially since you are caurbed straight fuel will be better choice.

 

I think 90 would be fine. Try it, and if you're worried, get a small bottle of octane booster the first time you put it in the tank. Go out and test ride, listen for knocking or pinging. If you get some, mix the octane booster in and stick with 91 from then. If not, stick with 90.

 

I checked it out with other HD pilots and they all use real gas not E10.
Here in South Florida they are already selling 15% ethanol which is proven to
destroy your machine or car, by corrosion. Pure 90 runs great in my XL1200C
and gets better mileage too.
...and NO ....HD doesn't recommend ethanol fuel.
Here's where you get the real stuff in the U.S. and Canada. I use it in my Corvette
and old Triumph too.
If you let E10 sit in you bike without driving it, it separates, the ethanol goes to the
bottom of the tank and becomes super corrosive and does damage.
http://pure-gas.org/?stateprov=FL

 

No funny gas unless its coming from your trousers then in the spirit of PC, anything goes.

 

real gas is the best, although the E10 shouldn't hurt anything as long as you don't let it sit a long time, most of us cant get real gas anymore, 90 octane should be fine,, I can run mine on 89 and hardly notice any difference.

BTW, Lucas is now making an additive for ethanol fuel, suppose to prevent corrosion and all that..