Ok, today I took a picture. Couldn't quite hit 23.0 again, but it was SOOO close!
The difference was probably that I had to adjust the cruise speed up and down a bit here and there more often today than yesterday because of traffic. This was done running on 87 octane, too.
My truck: Ram 1500 Outdoorsman crew cab, 5.7 L Hemi V8, 2WD, 3.92 gearing, "anti-slip" differential, 32 gal tank