How does Mazda intend to balance their rotary ambitions with 21st-century environmental considerations? We find out.
Hiroshima-based carmaker Mazda have long been a proponent for rotary engines, defying mainstream conventions and delivering some truly amazing driving machines – from the space-age Cosmo Sport of the 1960s, to the 24 Hours of Le Mans-winning 787B.
Decades of investing in and refining this pistonless internal combustion technology have earned the rotary engine – and by extension, the brand – a cult-like following around the globe. A mighty effort, considering 30 other licensees of the Wankel innovation decided to stop working on it completely.
But the world is changing, and emissions rulings have gotten stricter in recent times. Rotary power is no longer a force to be reckoned with like the good old days, and their admittedly poor fuel consumption performance has become a liability.
And while Mazda attempted to modernise it with the Renesis engine for the RX-8 or marry it into an EV (in the form of an electric drive unit for their MX-30 e-SKYACTIV R-EV) in a bid to get on with the times, it’s just not quite the same.
All of that’s about to change, however, with the Vision-X Coupe and the radically reimagined rotary technologies that it’s packed with.
Rotary Reimagined
Just a year ago, it was announced that Mazda would be reinstating its “RE Development Group” in the company’s Powertrain Technology Development Department of Powertrain Development Division. In short, 36 of Mazda’s finest engineers in charge of rotary engine development would band together once more to create next-generation engines and generators.
At the recent Japan Mobility Show 2025, Mazda showed off its Vision-X Coupe prototype, as well as a curious new innovation called the Mazda Mobile Carbon Capture device. During the press conference, the brand proudly proclaimed, “Mazda believes that the joy of driving can be a force for positive change for society and the planet”.
A bold statement, but is there any substance behind it?
The carmaker announced that the concept car was powered by a two-rotor turbocharged rotary engine with plug-in hybrid technology, building upon their 2023 Iconic SP concept, which was also rotary-powered. It packs 503 horsepower, an all-electric range of 160km, and up to 800km of combined range; a strong and compelling case for the Wankel engine’s rebirth.
Says Ryuichi Umeshita, Mazda’s Chief Technology Officer, “The rotary engine is characterised by the unique feel of its revs, and its satisfying sound and power delivery. It’s truly an engine where you can experience the joy of driving.”
But how exactly will this reinvented engine be a force for positive change?
Entering Carbon-Negative Territory
For one, the Vision-X Coupe’s rotary powertrain is able to accept biofuel – more specifically, the type that’s derived from microalgae. According to the carmaker, it works by allowing the Nannochloropsis algae to absorb atmospheric CO₂ before being converted into biofuel. Overall, carbon emissions are reduced by a whopping 90% as a result, surpassing expectations.
Their bold bet on microalgae instead of the more mainstream corn-based alternatives has other practical benefits too. Microalgae has relatively high oil storage capacity compared to other types of biofuels, which makes it easier to produce them in areas where space is a concern.
Mazda claims that with the Nannochloropsis algae, they are also able to extract oil with properties that are close to both petrol and diesel, expanding the possibilities of different engine variations.
And it gets even better.
The ingenious Mazda Mobile Carbon Capture device, which works in tandem with the rotary engine, captures 20% of the CO₂ from exhaust gases. This means that in total, we are looking at 110% in reduced emissions. In other words, Mazda is now entering carbon-negative territory, an achievement that’s virtually unheard of anywhere else.
Plotting the Path for Mass Production
Still, several hurdles lay ahead before Mazda can properly implement these wondrous technologies.
The brainiacs running the carmaker’s R&D department are still trying to figure out how to scale up algae oil production and create stable environments to grow them effectively, all while lowering costs. As Mazda explains it, “To grow microalgae in large quantities, we need large pools. Outdoor conditions are easily affected by weather, so we’re working on stable production methods. We hope to achieve mass production without compromising on oil quantity or quality.”
Mazda is also refining its CO₂-capturing technology to make it feasible in production cars. They have been putting it to the test in extremely demanding conditions, most recently at the Super Taikyu Series endurance racing championship held last weekend.
And finally, the rotary engine. While Mazda remains optimistic about it meeting global environmental standards, the company says it still has to comply with local regulations in various countries, and consequently, more time is needed to achieve this.
The Rotary Lives On
After years of hushed (and oftentimes unfounded) rumours floating around within industry circles, it seems that Mazda is finally putting its money where its mouth is, and getting serious about rotary development for a new age.
From restoring a dedicated rotary engine R&D team to investing in carbon-negative technologies that power their prototype, the Japanese marque is clearly looking into the future while still taking a leaf or two from their history books.
And if they manage to execute this properly, we could potentially witness a stunning revival that many enthusiasts have been praying for.
Article and photos by: Muhammad Mu’tasim (@mutasimdrives)
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