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maptyesterday at 4:56 PM1 replyview on HN

This is a negligible improvement to most things about an EV. Motors are already extremely power-dense.

There is a single exception, and it's a big one. Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight (the part of the car more closely coupled to the road surface than the passenger) and this impacts handling substantially. So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels. We're paying that bill already, on almost all production EVs. Quadruple the power density and simple, 1-moving-part wheel hub motors look like a lot better case versus central driveshafts and mechanical linkages.


Replies

coryrcyesterday at 6:22 PM

> Direct-drive, wheel-hub motors are not well-regarded right now, specifically because they increase unsprung weight

It will always be lighter to not have the motor in the wheel.

> So instead we backport a bunch of the mechanical infrastructure that transfers power from a traditional ICE engine to the four wheels.

No, we do it because it's smart and efficient for freeway-capable vehicles.

Wheels get banged up in use. They're easy to replace for different applications. They're exposed to 200 kph salt spray at hundreds of RPM. They are not a great place for motors.