[Gracana]

Kind of orthogonal. Traditional AWD and part-time 4WD systems are solutions to get power from a single motor to both the front and rear of a vehicle. AWD has a center differential to account for differences in front and rear driveshaft speeds when driving on high-traction surfaces. 4WD just locks the front and rear driveshaft rotation together, which is a simple and robust solution that only works on loose surfaces.

With separate front and rear electric motors, there's no center differential to worry about, and a sufficiently sophisticated motor control system can make it behave well on and off road.

[throwway120385]

This is probably the most succinct explanation I've ever read of the differences and the advantages of one over the other. I've been trying to understand this from different sources for years now.

[chrisweekly]

Thanks! Makes perfect sense. Great explanation!