Saw your request earlier, so I got a photo this afternoon on the way back from Mobile. It's what might be fairly described as an average "economy" setting at an average (?) altitude. Mixture is set at peak EGT, so it's not actually making 65% power; the EFIS is considering only MP and RPM. The resulting 8.8 GPH is misleading...too low. A Best Power mixture (say, 125 ROP) with the same MP/RPM would be more like 10.5 to 11.
The 9.1 GPH figure from the Lycoming webpage is too low for best power mixture at 65%. It doesn't even match the published Minimum Fuel Flow chart from the operating manual. At minimum flow, 9.1 would be 60%: