I don't drive much. When charging at home I use a 120v 15A outlet and the car charges at about 4 miles per hour of charging. I know the power use is less efficient this way, there is power use due to pumps and other various systems so a smaller percentage of the supplied current actually winds up charging the cells. How much less efficient is it? Is there any advantage to the Tesla wall charger beyond an increase in charging efficiency? I can get fairly close to the efficiency using a 240V 50A outlet and the supplied cord, allowing me to charge at 40A, not the 48A I'd get with the charger. If 4 miles of range for each hour of charge is enough for me, is there a down side to charging at 120V? That is just under 100 miles per 24 hours which is plenty. Is it harder on the car? I can install a 240V 50A outlet fairly easily. Is there any reason to put in a Tesla charger vs a 50A wall outlet? I live 2 miles from a supercharger so if I need a quicker charge, it is available.