Prototype internal combustion engine gets simple for efficiency

The folks at Road&Track are showing off what they are saying is a new prototype engine from Toyota. The free piston engine, which essentially gets rid of everything below the piston, simplifies the energy generation process for electric cars.

Traditional fossil fuel-powered vehicles require a crankshaft to rotate the transmission, axles, and wheels for movement. But, since most range-extended electric vehicles only use an internal combustion engine to generate electricity, the whole package can be simplified.

Toyota’s prototype is essentially a two-stroke setup with a piston sliding through a chamber of magnets to generate electricity. Valves are also electrically operated and the engine can be fired using compression instead of a spark plug for even more efficiency. The engine is said to have a thermal-efficiency rating of 42 percent and develop 15 hp.

About Mark Stevenson

Mark Stevenson is a former IT professional turned freelance automotive writer and news editor for He's a member of the Automobile Journalists Association of Canada and former member of the Texas Automotive Writers Association (TAWA). Mark spends an inordinate amount of time on motorcycles and resides in Dartmouth, Nova Scotia with his two dogs - Nismo and Maloo. You can find him on Twitter and Facebook.