66 MPG US average / 3.6 L/100 km.
That was on a 100 km / 62 mile round trip today, and that's the car's second best MPG performance.
And this time, there was a tailwind on only ONE leg of the trip!

(Headwind on the way there.)
More of this trip was spent at the speed limit (80 km / h = 50 mph) than this weekend's 72 MPG result. And temps were cooler.
And it's still running on winter grade fuel.