I really suspect CarWings' data. I have the updated software on my 2011.
I'm averaging 4.3 m/kwh on the odo, 4.4 on the screen, and a whopping 6.1 m/kwh according to CarWings. I don't think so--especially when, between two days for the exact same commute and closer-than-a-fly's-wing of the same...