I filled up at Meijer again. Once again, I only filled up with 87 Octane gas.
14.736 gallons of regular. My tank is now at a little over 10% ethanol, octane is a little over 87.
It feels like the throttle response is sluggish (not much different from when I had 50% ethanol in there). I've got the ignition advance on the scangauge, and it looks like it is significantly retarded from when I was running lots of ethanol, like 4 or 5 degrees of timing.
I actually wanted to fill up with premium, but I was on autopilot when I was filling up (after 4 hours of overtime) and hit 87 without thinking about it.