In September, I replaced my tires, and both the dashboard and LeafSpy seemed to agree that my miles/kWh dropped by 10% or a little more. Driving conditions for the first few weeks were still almost entirely dry road, daylight and no climate control.
Then, over the last month, daytime high temps have dropped at least 20° F, roads are wet most of the time, over half of driving is with headlights on and climate control has to run continuously to safely see out of the windows. My LeafSpy mileage and observed range has CRATERED by at least 20% more, yet the dashboard average trip mileage has barely budged. It may have dropped 2 tenths (4%). Does the car's mileage calculation ignore power going to heat and lights?
I mostly ignore the GOM, but I think at least it has responded somewhat more realistically to the changed conditions.