Since when does "efficient" mean a net-gain in energy? Seems like Broder needs to revisit his high school Science AND English classes.
He simply believed that stop & go city driving would help instead of hurt his mileage. Whether that's correct or not depends on the maintained speed. Driving at. steady 75mph on a highway is quite possibly less efficient than stop and go downtown. At 55 mph, maybe not, but how is Broder supposed to know this off the top of his head if a Tesla phone rep is giving him bad info?
In contrast slower city driving speeds are more efficient and electric vehicles have a unique benefit in stop and go, low-speed driving due to regenerative braking
http://www.teslamotors.com/blog/model-s-efficiency-and-range