> BYD builds a unit with an integrated motor, differential, axle, and wheel hubs

So wait, the whole axle is solid then? Like a 1960s pickup truck but with all the weight of the motor and gearbox hanging off it too?

That must give it ridiculous unsprung weight.

it's not really like a 'live axle' from an older truck, it's more like a de-Dion style suspension (or dead axle).

https://en.wikipedia.org/wiki/De_Dion_suspension

you still see these in velocipede-style vehicles commonly.

and to your point : a dead axle is an effort to reduce unsprung weight compared to a live axle; it also lets you actually use alignment as a remediation for asymmetry issues rather than just pre-delivery straightening.

On the platforms I've worked with, the weight isn't the issue so much as the quantity of expensive and vibe sensitive parts that are unsprung.

Looks like they do in-hub motor for buses and in-differential(like everyone else) for passenger cars?