Fuel - Regular or Premium?

[ehud42]

I just bought a '78 XS500. The previous owner was pretty fussed about babying it. He insisted on running premium fuel in it.

Thoughts? I'm in Canada. Premium now may contain up to 10% Ethanol. (I used to buy premium for my lawn mower / snow blower to reduce exposing rubber bits to ethanol).

 

[mildrider]

I recently bought a '80 xs400. The owners/overhaul book recommends premium fuel (actually 93 oct, which isn't available). I can get non-ethanol 91 oct. locally.