Autocar has learned that Mazda engineers are hard at work trying to develop a rival to the Chevrolet Volt – a car which uses a petrol engine to charge a battery pack which powers the wheels via an electric motor.

Senior sources say that trials are currently underway in Japan, with a prototype that uses a rotary engine to charge the battery pack. The tests are sufficiently advanced that Mazda has a working prototype in a Mazda 5 MPV bodyshell. Company bosses are said to be keen to put this system into production but no firm decisions will be made until the cost of batteries is reduced.

In the meantime the company will concentrate on simpler green technologies. The first stop-start Mazda will go on sale in Japan next year and the system is expected to be rolled out globally on a variety of models.