The MPGe Tesla advertised also is. Then they use that to correspond to % remaining battery.

All EVs get wildly different range depending on outdoor temps (I get 30% lower range in winter) and their hysteresis is way higher than an ICE car. But, their range numbers are accurate for when they are measured under ideal circumstances.

I regularly do better than rated range. Others have a heavy foot and do worse. Kinda par for the course.