Mazda rotary engineEnlarge Photo
Mazda’s last car to be fitted with a rotary engine was the RX-8 sports car, which ended production earlier this year. The RX-8 used its rotary engine to power its wheels, though this proved to be a rather inefficient form of propulsion.
For its return, the rotary will be used solely to charge a battery, which will then power an electric motor driving the wheels of whichever car it is fitted to. There have been reports that Mazda was testing a rotary extended-range vehicle that ran on hydrogen, though any production version is likely to use regular gasoline.
Rotaries, like most internal combustion engines, are most efficient when they maintain a steady rpm level. Acting as a range extender would allow the engine to operate at a constant rpm.
“The rotary has very good dynamic performance, but if you accelerate and brake a lot there are efficiency disadvantages,” Yamanouchi explained to Autocar. “The range extender overcomes that. We can keep it spinning at its most efficient 2,000 rpm while also taking advantage of its [compact] size.”
It’s not clear yet what type of vehicle Mazda will launch its new rotary extended-range drivetrain in.
Note, Mazda wasn’t the first to proceed down the rotary extended-range development path. Instead, it was Audi that showed the rotary-packing A1 e-tron concept at the 2010 Geneva Motor Show. That allegedly led to talks between Audi and Mazda, and rumors that Mazda was developing a special-purpose rotary engine for the Audi A1 e-tron. While Audi chose to forgo a rotary for its eventual road-going A1 e-tron, it appears Mazda won't doing the same.
Stay tuned for an update.