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Old 04-21-2021, 05:20 PM   #5 (permalink)
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The 99% efficiency is for the inverter alone, not the entire drivetrain.

The efficiency of electric motors drops at high power outputs.
Especialy with induction motors like tesla runs.
It is true however that efficiency also drops at super low power output.
It's not that much overall, but going from 99% to lets say 90% means 10x the load on your cooling system for a given power output, however we're talking about topspeed at 197,6 hp vs cruising at 42,9 hp aka 4,6x as much.
So the thermal load might not be 4,6x as much, but 46x as much.

The drop to 90% is just an estimate, but I guess you see the issue.

With ICEs you have a lot higher losses, but a lot of them dissapear through the exaust and the rest is at a high temperature, wich requires less cooling air to get rid.

Anyway, EVs need a more complex thermal management system including but not limited to adjustable air intakes to reduce or even eliminate cooling drag when possible and provide maximum cooling capacity when required.
I see no reason why an EV should have any cooling drag at all when it's freezing and you're not driving fast.
The passengers greatly appreciate the waste heat in that scenario.
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