Where do you get the 6.5% charging loss. I have seen higher figures like type2 10% and UMC 15%. DC charging on a 3rd party charger may be even worse. superchargers are the only ones to charge based on how much DC actually reaches the car
Over the first 10K I did if you compare the total consumed by the car vs total kwh recorded by my charger then the difference was about 30% ( preheat, sentry, charge loss etc and mainly over the winter) so if you want a realistic measure of what you will be spending per mile a significant correction factor is needed. The wh/m figure from the car is really only any use for calculating range not cost.