New Mazda Patent Hints At Powerful Future Rotary Engine Possibility

Unless you're a car enthusiast, you may not know that Mazda is the automaker most closely associated with rotary engine technology. Now, the company is taking that technology a step further with a new patent filed in January 2026 and published in August. This patent covers an Exhaust Gas Recirculation (EGR) system designed specifically for a two-rotor, turbocharged rotary engine.

Perhaps the most interesting part of this new system is the design. Mazda has placed part of the exhaust-gas passage inside the rotary engine's side housing. As the exhaust gas passes through this section, engine coolant can help remove heat before the gases reach a smaller EGR cooler. This gives Mazda a way to send a large amount of cooled exhaust back into the engine during heavy operation without needing more space around the engine itself. The patent also describes a rotary engine using separate exhaust paths, with the higher-energy exhaust directed toward a turbocharger and cooler exhaust used for the EGR system. This could help control exhaust and catalytic-converter temperatures.

This design is an important step forward, as rotary engines typically have higher exhaust temperatures and higher hydrocarbon emissions. That combination makes it tougher to meet emissions requirements. However, the patent does not confirm a new production rotary engine or a specific vehicle that will feature such an engine. As of this writing, Mazda has yet to publicly release any information on this new design.

A rotary engine is unlike a conventional engine as it uses a triangular rotor that spins rather than pistons that move up and down. Mazda was the first automaker to use this technology in a production vehicle, specifically, the 1967 Cosmo Sport. As time went on, the company continued to develop the engine, working on features like power output, exhaust-gas systems, and durability. Mazda eventually discontinued the rotary engine in 2012 when the RX-8 went out of production.

However, this complicated engine did make a comeback in 2023 with the brand new MX-30 e-SKYACTIV R-EV. This was a plug-in hybrid vehicle, and the 12th Mazda model to feature a rotary engine. Then, in 2024, Mazda reestablished its dedicated team of rotary development engineers for research focused, in part, on regulatory requirements in major markets. Additionally, the group was tasked with researching eco-friendly fuels and the use of rotary engines as generators.

This move was important for the MX-30, as the rotary engine powers a generator in the vehicle rather than the wheels, which are handled by the car's electric motor. Mazda chose the rotary engine for the MX-30 because its compact design can produce the needed output from a relatively small power unit. This allowed Mazda to use both the engine and generator with the electric motor in a more streamlined package. However, Mazda has since discontinued the MX-30 R-EV in Europe, due to changing customer demands and different production priorities.