Comment by jabl

> There were many older models of BMW that had an electric water pump. If that sounds silly, well, it is. And it failed frequently and was again, very difficult to replace.

On the face of it, it's not actually a bad idea. The electric pump can run at an optimal speed regardless of engine rpm. This means the pump can be downsized, because otherwise if it's driven directly from the engine it'd have to be sized for the worst case scenario of low rpm and high load.

Same reason why many vehicles nowadays have electric radiator fans rather than driven directly from the crankshaft like in the "good ol' days". (Of course with transverse mounted engines a crankshaft driven fan doesn't really work either, so that's another big reason to go for an electric fan.)

Now, of course this concept can be badly implemented, just like any other part of the design.