Don't expect anything written in stone anytime soon...
This is a hazy area, and who can say what you are really getting for fuel nowadays. I know when I got to Quebec my truck doesn't get as good gas mileage on QC gas.. Why is that? I don't know. Gas blends are always changing and especially in non-brand name pumps you may be getting almost anything.
In doubt and want to play it safe? Run your F7 in the Ethanol position. That's a hell of a lot safer than wasting your money on 93 octane, especially when its likely to contain MTBE.
This is a hazy area, and who can say what you are really getting for fuel nowadays. I know when I got to Quebec my truck doesn't get as good gas mileage on QC gas.. Why is that? I don't know. Gas blends are always changing and especially in non-brand name pumps you may be getting almost anything.
In doubt and want to play it safe? Run your F7 in the Ethanol position. That's a hell of a lot safer than wasting your money on 93 octane, especially when its likely to contain MTBE.