OK, today's trip was to Hockley Valley which is approx 100 km (each way) of back roads and a few small towns. Sunroof open both directions.
Going = 5.2 L/100
Small headwind, a bit of traffic getting out of town, and some hwy construction.
Return = 5.0 L/100
Similar conditions but small tailwind. Had it down to 4.7 L/100 as I was coming into Guelph where I stopped to pick up some food on the way home.