I am running the local 93 octane premium which states 10% ethanol. When I test it, it shows 6% ethanol content.
Previous testing with this fuel has shown it normally makes best power around 12.2 to 1 a/f ratio. This thing is showing 12.8 to 1 on the O2 meter right now on the top of the pull.
Plug readings and testing so far confirmed that it needs more fuel.
Best power so far has been with 33 degrees total timing.
I also have available around here some non ethanol 93 that usually makes more power and likes a slightly leaner mixture.
Keith