BMW i3 with range extender did that, don't know what kind of engine. Not quite intended as a PHEV, but I suppose it could run just on the ICE like most current

BMW i3 with range extender did that, don't know what kind of engine. Not quite intended as a PHEV, but I suppose it could run just on the ICE like most current PHEVs Toyota's hybrids (Prius, etc.) have used Atkinson cycle ICE, instead of Otto (one maximizes fuel economy, the other power delivered, I heard).