You gotta love Mazda’s dedication to the rotary engine. It has been more than 40 years since it licensed the Wankel engine technology. During that time, the little engine that could has powered everything from mini pickup trucks to futuristic sports cars. What is it about the rotary engine that makes it so endearing? Primarily, it is lighter and smaller than a traditional piston engine with similar power.
That power per pound ratio has made it useful for lots of things besides being tucked under the hood of an automobile. Mazda rotaries even made it into a few small airplanes where weight is a critical factor. Now, Mazda says it may use a small version of of its rotary power plant as a range extender engine for plug-in hybrid vehicles. Once again, its compact dimensions and low weight could make it ideal for just such an application.
Martijn ten Brink, vice president of sales and customer service for Mazda Motor Europe told Dutch automotive news source AutoRAI recently that Mazda has an electric car coming to market in 2019 and that it will be equipped with a rotary range extender engine. Whereas the normal Mazda rotary uses two rotors, the RE engine will be a one rotor version, saving more weight and space. He says the vehicle will be about the size of the current Mazda 3 and may be a crossover-style sport utility vehicle.
According to Engadget, the engine will be mounted with the rotor in a horizontal plane. That will be a first for this engine, which usually spins the rotor in a vertical orientation relative to the chassis. BMW also uses a range extender engine adapted from its existing inventory for its i3 electric car. When customers order the REx version of the i3, it comes with an adaption of a BMW 650 cc motorcycle engine on board. Workhorse also plans to use that same BMW engine in many of its upcoming plug-in hybrid delivery vans and pickup trucks.
Engadget reached out to its sources at Mazda in North America but was unable to confirm the details about the new model. Although the company has filed for US patents on range extender technology and has announced that a new PHEV with a range extender engine is on its way, no details about what engine would be used to drive an onboard generator have been released. Most plug-in cars with range extender engines like the Chevy Volt and new Kia Niro use conventional four cylinder engines. The bulk of those engines limits one of the potential advantages of electric cars — better packaging that leaves more space for people and cargo inside.
In theory, a tiny Wankel engine should be ideal for this purpose. We will have to wait to see what the reality turns out to be. The car, whatever it is, is expected in showrooms sometime in 2019. As always, anything from a traditional car company that moves the electric vehicle revolution forward is welcome news.