It's called "real world driving". Look, this is no different from Tesla claiming a 280 miles range that nobody can achieve. Not saying it is right. What I am saying is: We need better tests.
No vehicle meets manufacturer specifications in this regard, electric or IC.
To be clear, I am not saying this as a negative. I am simply stating it as a fact.
I have not taken care at all to drive my Model S in an efficient manner, and I still have an average of 315Wh/mile over about 8,000 miles of driving so far, where 300Wh/mile is rated efficiency.
Beyond that, the truth is you cannot get the rated range because that would mean draining the batteries to zero. Real range anxiety, depending on where you drive, starts to come in somewhere below 50 miles from fully drained.
You also have a difference in performance between summer and winter driving. If you have a short daily commute, the combination of the "off" state drain on the battery overnight and the car warming or cooling the battery pack while parked in cold or hot weather can have an impact on available range and performance.
BTW, I am NOT saying any of this is bad. I am simply saying these are realities of the contrast between advertised specifications and performance under real life conditions.