We get all sorts of big shiny new trucks in our shop, and ever one of them touts jaw-dropping mileage figures. Customers typically come pounding down our door after a year or two demanding we overhaul their expensive new Mack or Peterbuilt because "the mileage aint there." We cannot do anything to fix it most of the time.
The problem starts between your foot and the pedal, at least in the good ole USA.
Most americans rarely follow the speed limit, they dont use their cruise control, and they dont practice defensive driving at all. Jackrabbit starts at the red light, hard braking, acceleration to overtake instead of "underpassing" to enter a lane, and insisting they can maintain speed at any grade and at any elevation, mileage be damned. flooring it up a hill, for example. oh, and dont forget lots and lots of climate control...that cabin is 65 degrees in the summer or they just wont drive.
Id be really shocked if any of these 3 year tesla owners could pass a CDL course, remembered their turn signals, or even bothered to check their blind spots or tire pressure and wear.