Just as a data point. I filled up on friday, and drove 5 miles home and to the grocery store with a low 60's after that. Had some traffic. Usually in the low 70's mpg after than circuit. Did not drive the car over the weekend (did my errands on foot, as I need the excercise). Then drove to work today and back - 57.6 mpg. It was about 7 F this morning at startup. I slept in (did not wake before the alarm), and only got about an hour of block heater.
