The problem for us in Australia (maybe anywhere) wanting to rely on the Lycoming auto fuel approvals is that it specifies a particular specification of fuel. It doesn't just say 95 or 98 or whatever. Is the fuel we buy here to that exact specification? Doubt it/probably not. But if it was, how would you know? The dude, chick, or dude-chick/chick-dude (to be PC) at the Caltex aint going to know. As it says in the bulletin, the fuel must agree with all specifications in table 2. Lycoming has tested their engines on that exact fuel, not just any old fuel that came out of a pump at the Kwik-Fill on Lycoming Creek Road in Williamsport PA. Lycoming would never say "oh, use any old auto fuel" because they don't know and have no control over what you are getting. Their publication really says if you use this exact fuel, like we tested, you're good.
Are people using ordinary pump 95 or 98 in their LYCs here, now? You betcha.
I haven't looked into what say Rotax says to use - maybe they say "just use 95-98 auto fuel"
Jabiru says MOGAS RON 95+ if avgas is not available (and see/follow the Jabiru Service letter) That's an interesting point. If I arrived somewhere that had MOGAS and AVGAS on tap, I must choose AVGAS. Same at home base which has AVGAS avail. I should not be running MOGAS bought locally - avgas is available. I did run MOGAS for about 2 years, absolutely no difference noticed, other than black exhaust pipe with mogas, and it was a PITA to get - I didn't like transporting jerry cans in the car and stink the car out.
Hope this discussion has been a bit thought provoking. Do I care/mind if you use mogas? Nope! I'm not your mother. nie mój cyrk, nie moje małpy