ARtraveler
R.I.P. Dwayne
Suggestions I'm playing around with. I started using regular gas, using ECO, keeping under 3k RPM and shifting at lower RPM's like 25/30k. I'm getting fairly consistent MPG at 39/41. Don't be looking at that little green arrow. Use your hearing to make your lower RPM shift points. If you try to make the shift too low in the RPM range, it won't shift. If you've running 91 octane and want to try regular, try to fill a nearly empty tank twice with regular and be gentle on the throttle because at first it will want to knock. That's not good. It takes a while for the ECM to adjust so give it a couple of tanks.
Also running 87 octane this season. No ECO. I am consistently getting 38 - 39 mpg. I shift at 3500.