Hydrogen RX-8

Mazda has been giving more details of the dual-fuel petrol-hydrogen RX-8 to be displayed at the Tokyo Show. It's making the point that, while four-stroke engines need many modifications to run on hydrogen, converting a rotary is a much less complicated process.


In particular, because it keeps the injection, compression, ignition and exhaust areas separate - unlike the four-stroke system - there's no chance of pre-ignition of the hydrogen gas. The twin-rotor Mazda prototype uses two injectors in each rotor housing to put the hydrogen directly into the intake chambers.

Mazda says a production version of the dual-fuel RX-8 is still several years off, but it will push forward the development, as well as continue its work on regenerative braking and the stop-at-idle fuel saving system.