Fifty years ago today, Mazda pulled the sheet off its Cosmo 110S at the 1967 Tokyo Motor Show. Even on the face of it, the white two-door seen below was a radically sporty departure for a company best known for producing miserly economy cars and commercial vehicles. But the Cosmo's most significant contribution to automotive history wasn't its racy proportions or athletic intent, it was what nestled under its hood: the rotary engine.
Now, it's true Mazda didn't invent the novel pistonless engine, it licensed the high-revving powerplant design from Germany's NSU (later part of Audi) and Wankel. But, for half a century, Mazda would go on to do more to popularize and advance this type of engine than any other automaker, going on to stick the rotary in everything from race cars to a small pickup and a 26-passenger bus. Along the way, Mazda built just shy of 2 million examples of Felix Wankel's iconoclastic engine.
The rotary engine is undoubtedly best known for powering a series of flyweight RX-series sports cars, particularly various generations of RX-7. Sadly, Mazda hasn't offered a Wankel-powered production car since its quirky RX-8 sports car went out of production in 2012. Despite its inherently entertaining nature and extreme space efficiency, this type of engine has proven difficult to certify for emissions, and there have been long-reported durability and oil-consumption issues.
That said, over a half century of development, Mazda has remedied many of the rotary's inherent shortcomings, and the company insists it is continuing development. For instance, there has been talk of using the low-inertia engine design as an onboard generator in a range-extended hybrid, where its innate lack of torque wouldn't be as much of a hindrance and its compact size would be a particular asset.
But that doesn't mean Mazda is giving up on using the rotary in performance applications. Indeed, the company whet the enthusiast world's collective appetites with its long-hooded RX-Vision concept back in 2015, and rumors persist that Mazda may reveal a new Wankel-powered show car at the Tokyo Motor Show this fall.