Toyota has come up with a prototype engine for range-extending electric vehicles which uses a 'free-piston' system that cleverly incorporates the electricity generation element without requiring rotary movement or a crankshaft, writes Brian Byrne.
Part of the piston is a magnet through which the compression-expansion linear movement interacts with a coil around the cylinder to provide electric current.
A double bank of these units could provide range extending power to run a supermini EV at 120k/mh on longer journeys.
The concept has the advantage of being more compact and less complex than adapting a standard petrol engine.
