="GerryAZ"]...The energy use displayed by CarWings makes it appear that the car is much more efficient than it actually is...
It looks like you may misunderstand what kWh data CarWings is displaying.
Read my post above yours, and look at the AVTA links I posted.
Evidently, the kWh use report from CarWings, and the identical kwh use shown the dash and nav screen m/kWh displays while you drive, are reduced by the factor of "Overall Trip Efficiency...calculated by dividing the DC energy out of the battery (A+) by the AC energy from the EVSE "
http://avt.inel.gov/pdf/fsev/fact2011nissanleaf.pdf
http://avt.inel.gov/pdf/fsev/fact2013nissanleaf.pdf
The large efficiency variations, from 81% to 84% in the 2011 tests, and from 82% to 85% in the 2013 with the higher kW charger, IMO probably reflect variations in the percent of total capacity the LBCs of AVTA LEAF allowed them to access, not large variations in efficiency.
So if you want to find your own LEAF's
nominal "Overall Trip Efficiency", I suggest you collect as large a sample size of discharge/recharge events as is practical.
If you monitor your LEAFs
nominal "Overall Trip Efficiency" you probably will also see you get large increases in efficiency by avoiding the top of your pack capacity, that above "80%"charge, and also a significant increase in efficiency when charging at higher battery temperatures.
="GerryAZ"...The difference between energy use displayed by CarWings and actual charging energy from the wall is over 25%. I am surprised that the data for the 2015 is no more accurate than the data was for the 2011...
If that discrepancy really is "over 25%" (below 75%
nominal "Overall Trip Efficiency") on average, I suggest you look into it, as that may mean your dash and nav screen are showing the same error, a large underreport of kWh use reflected in an erroneous report of higher m/kWh.
The largest monthly discrepancy I've seen on my 2011 was last January, over a five-recharge sample measured from the meter, beginning the charge between the LBW and VLB, and ending at "80%" charge, was ~77%. that
nominal inefficiency IMO was certainly much higher than actual.
I estimate the underreport error in my LEAFs
nominal kWh use that month was then nearly 10%, meaning my actual "Overall Trip Efficiency" was probably ~84.5%, over those five sessions.
Of course, my dash/nav screen m/kWh displays reflected the same error while I drove, and it seems very likely my LBC using the same erroneous kwh use data was what caused it to overstate my pack's actual loss of capacity, as displayed by the (pre-Leaf Spy)
battery app.