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IMHO it largely boils down to firmware and how much amps it allows to flow to the motor at each temperature. It also depends on battery charge and temperature. And motor temperature and ... Different FW revisions could allow for different max numbers that are function of other parameters.
ICE engine power also varies greatly from one new car to other new car and then varies with engine abuse, fuel and oil quality, air temperature and humidity, etc. The only difference is Tesla is making more rapid revisions to these public specs as is usual for other car makers (once a year for a new model year).
Maybe they made some new PEM upgrades. Maybe they've gotten better at making the motors. Maybe the specs on the IGBT's improved or became more consistent.
For that matter they don't seem to know how big the battery pack is. The received wisdom is 56k total and 53k usable, yet their quite reliable range spreadsheet uses 55k.
For that matter they don't seem to know how big the battery pack is. The received wisdom is 56k total and 53k usable, yet their quite reliable range spreadsheet uses 55k.
Yes, this seems funny until you start to understand batteries and their capacity. This is completely different from say gas tank volume which only varies a tiny bit with temperature.
Reality is, the size of battery pack is for them to decide. They could decide it is 60 kWh and allow for ~280 mile range with exactly the same number of the same cells. And it would work, but not for 7 years.
On the other hand they could decide it is only 50 kWh and only allow for 200 mile range with again the exactly the same number of the same cells. And it would work, and for a bit longer than 7 years. But probably not that much longer.
Battery capacity is a function and/or compromise between reliability, longevity and performance. They are still learning and gathering data from current users on how these cells really perform on average in practice, how large are varieties, what is good and what exactly is bad for them and tweak the firmware to optimize as much of those parameters as possible. If they decide they should ease a bit on max discharge current at lower temps, car max power goes down. If they see they were a bit to conservative and allow for a bit higher max discharge without adversely affecting the lifetime and everything, car max power goes up.
It is a delicate business and one of the main reasons Mercedes and Toyota choose to buy this knowledge from Tesla and not reinvent it.
