Rotary engine returns in different role

MOTORING NEWS - Mazda's legendary Wankel rotary engine is coming back. The engine will be used as range extender in upcoming Mazda electric cars. Mazda is planning to have 95% combustion-electric hybrid vehicles by 2030 and the remaining 5% will be be pure battery-electric vehicles. The engine's small size to power output ratio, quiet operation and fuel flexibility are the reasons behind this decision.

The engine's small size and high power output make multiple electrification technology solutions possible via a shared packaging layout.

Taking advantage of the engine's compatibility with gaseous fuels, the rotary-powered range extender is designed to also burn liquefied petroleum gas and provide a source of electricity in emergencies.

The rotary engine was first used as a range extender on the Mazda Cosmo.

The choice is also justified by a rotary's almost vibration-free functioning and the fact that it has fewer moving parts than a conventional piston engine, helping with maintenance and longevity.

A flat, horizontal layout will likely make packaging easier, possibly allowing a rotary range extender to be housed in an underfloor compartment along with a hybrid's batteries. The first Mazda hybrid with a rotary range extender is expected to come out in 2020.

Cutaway of Mazda rotary engine that has been redeveloped.