"Yeah, and as stated by eve pro Tesla websites, this is likely on a flat surface without hills and hardly any load, because the math doesn't add up otherwise."
Hills don't affect economy much on EVs because they can regen on the way back down instead of using brakes to turn fuel into heat. They lose maybe 10% to heat in the wiring and the batteries which is probably less than the average semi loses to increased air drag if the driver stays off the brakes and lets the truck speed up going down the hill. I have a picture of energy consumption graph of a Model 3 going over Monteagle on I24 between Nashville and Chattanooga. Almost all of the extra energy expended going up one side was recovered going back down the other.