Free piston petrol range extender?

[RoverP6B]

This makes for very interesting reading.

http://www.roadandtrack.com/car-culture/a6326/out-...

I wonder if this could be applied to conventional piston engines and thus do away with the alternator, use all electric ancillaries rather than sapping engine power?

[RoverP6B]

Hmm, right... it seems such a simple concept that it's a wonder it wasn't around a century ago...

[RoverP6B]

Double-acting piston engines were the norm in the steam era...

I don't understand why conventional single-acting petrol/diesel piston engines would be used as range extenders. They're much too complex, heavy and inefficient. A gas turbine or wankel makes much more sense. Jaguar obviously showed the CX-75 with the former, and although it was shelved, I think they've retained their shareholding in Bladon Jets, while Audi showed off a 50cc wankel range-extended A1 EV.

[RoverP6B]

Well, a microturbine shouldn't actually need servicing, the battery pack will go first.

I wonder if they could stick the 1.6 litre straight six bike engine in the i3? Or, better still, in the 1/2/maybe 3-series as the -16i engine?

[RoverP6B]

Even a tiny little thing like a hairdryer?

The whole reason turboprops/turboshafts replaced pistons was their greater efficiency.

[RoverP6B]

I know that, but running the ancillaries with electric power rather than pulleys is more efficient.