Mazda aims to join the electric vehicle game in 2020 by re-inventing the rotary engine as a shoebox-sized range-extender.
It is believed by the Japanese auto manufacturers that this move will bring a new lease of life to a form of combustion engine used occasionally by Mazda and others since it was invented by Felix Wankel, who built his first prototype with NSU in 1957. This has not been used by Mazda since the RX-8 went out of production in 2012.
Now, the engine will be mounted horizontally for better packaging, allowing it to be located under the rear floor panel of what appears in the patent’s schematics as a compact five-door hatchback.
The rotary engine drives a generator which charges a lithium-ion battery under the car’s rear footwell, with the range extender, generator inverter and fuel tank positioned between the rear wheels.
According to rotary engine expert, professor James Turner from the University of Bath, the Wankel engine isn’t as good as a conventional reciprocating engine for fuel consumption, but since its only running for short periods of time then it is less of an issue.
The engineers have patented an electrically-heated catalyst system that will automatically ensure the catalysts are at the right operating temperature to remove harmful CO2 and NOx emissions from the tailpipe gases. Any oil mist residue is captured and returned to the intake passage side of the engine, preventing it from contaminating the catalyst and degrading its effectiveness.
Mazda also hopes that by the end of the next decade, electric, hybrid and potential alternative fuels such as LPG, hydrogen and CNG will halve its ‘wheel to well’ CO2 emissions.