A report just landed into EV efficiency and the factors that impact it.
I've stolen the graphs as they tell quite a story.
Energy consumption increases at about 0.5 kWh/100km per 10 kWh of extra battery.
The impact of frontal area is enormous, with about 0.9 kWh/100km per 0.1 m^2 (i.e., the difference between an VW ID3 and ID7).
You can see similar correlations with overall vehicle mass, and unsurprisingly, vehicle cost!
EV efficiency correlations
EV efficiency correlations
Tesla Model 3 Performance
Oversees an 11kWp solar array at work
Oversees an 11kWp solar array at work