Too good to be true?

Dashboard says I average 5.2 mi/KWh around town pretty much all the time last Sunday morning I drove from Ballard to Issaquah high school and back. L1 charged to 100% and reset energy history.

Fifty miles round trip, first five across town as per usual. 1st mile or so down I-5 moving with traffic at 60, then on I-90 set cruise to 53 going up and cruised at 56 coming home (18 miles each way on I-90). Got back to my driveway showing 51% charge and 5.5 mi/kWh on dashboard for the day.

Seems way better than expected for this speed. What gives?

According to Google Maps, that route has almost zero net elevation change. So, I would expect good efficiency for that route in decent weather. There was likely very little wind.

Not that surprised, as I've had similar efficiency on trips like yours.