On my 2nd tank now. The ethanol station is about 35 min (completely) out of my way one way, so I also filled up 3 gal in a gas can from my last visit a couple weeks back.
Instead of doing 3 gal + full tank of 91, on my 2nd fill up, I decided to do 3 gal + 8 gal of 91 to test out a stronger Ethanol mix.
In all honesty, I haven't been able to buttdyno any major differences. Maybe I got used to it already, or the weather in winter isn't the greatest to be having fun spirited drives. I do 97% city driving so normally on 91 tune, I'm getting about 240 mi/ tank. I've noticed my last tank, I got about 200 miles. LOL...! Pretty much same driving habits. Tank of E30 really doesn't last long, does it? haha
I think after my current tank is done, I'll wait until spring before I try it again. It doesn't seem worth it right now with the weather and how often I'll probably have to fill up if I want to sustain this, and how far the ethanol station is.