Stats after 6 months of ownership

I've owned my Prime for 6 months. I keep a spreadsheet of the daily stats and use those numbers to calculate these numbers, among other things. MPG is based on gas purchased at the gas pump. kWh is reported by the car (miles traveled / miles/kWh on Ev-only days), not by a separate meter.

Average MPG when on gas: 59.8 MPG
Average Miles/kWh on electricity: 5.2 = 175 MPGe

I expect both to decrease with the onset of winter here in Colorado, but these numbers are simply outstanding.

 

Over the same period of the year and doing much of the same driving, my 2004 averaged 52.4MPG.