The Mazda Eunos Cosmo with a Rotary Engine

The Mazda Eunos Cosmo, introduced in 1990, was known for its three-rotor rotary engine, advanced technology, and luxury focus. It occupies a unique place in Mazda’s rotary engine lineup and automotive history as the only production road car ever built around a triple-rotor rotary powerplant.

Where the Eunos Cosmo Fits in Mazda’s Rotary Lineup

Mazda’s relationship with the rotary engine spans decades, from early experiments to lightweight sports cars and endurance racing. Models like the Cosmo Sport and RX-7 proved the rotary’s performance potential, while Mazda’s racing program demonstrated its durability at the highest levels of motorsport.

The Eunos Cosmo took a very different approach. Rather than focusing on speed or handling, Mazda asked whether the rotary engine could power a luxury grand touring coupe capable of competing with European flagships from Jaguar, BMW, and Mercedes-Benz. The Cosmo was the answer to that question, repositioning the rotary as a symbol of refinement rather than raw performance.

The 20B Three-Rotor Engine

At the heart of the car was the 20B-REW twin-turbo rotary engine, the only three-rotor rotary ever installed in a mass-production road car. Officially rated at 280 PS and 41.0 kg-m of torque under Japan’s “gentleman’s agreement,” the engine was widely believed to produce significantly more. Its defining trait was smoothness, delivering turbine-like power ideally suited to long-distance cruising.

To achieve this balance of performance and quietness, Mazda developed the world’s first sequential twin-turbo system for a production car, using a small turbo for immediate low-speed response and a second turbo for sustained high-speed power.

Advanced Technology Ahead of Its Time

Beyond its rotary drivetrain, the Eunos Cosmo stood out for its technology. It featured one of the world’s first production in-car GPS navigation systems, integrated into Mazda’s touchscreen Car Control System. A digital dashboard, mobile communication features and extensive electronic controls made the Cosmo feel closer to a concept car than a typical early-1990s production vehicle.

Original Eunos Ad

A Luxury Statement

Sold under Mazda’s upscale Eunos brand, the Cosmo was intended as a flagship model and a preview of Mazda’s luxury ambitions during Japan’s bubble economy era. Its high price and limited production ensured exclusivity but ultimately restricted its market to Japan. Fewer than 9,000 examples were built, making the Cosmo one of the rarest chapters in Mazda’s production history.

A Short-Lived Experiment With Lasting Impact

Production of the Eunos Cosmo ended in 1995. The idea of a rotary-powered luxury flagship proved too niche, and Mazda shifted its focus back toward sports cars and racing, where the rotary engine would achieve its most famous successes. The Cosmo remains a reminder of how far Mazda was willing to push its most unconventional engine, not just toward speed, but toward prestige and technological ambition.

See the Mazda Eunos Cosmo in Person

See the Mazda Eunos Cosmo at the Tampa Bay Automobile Museum during the Rotary Engine exhibit, where it appears alongside rare rotary-powered cars and motorcycles that trace the full history of one of the most unconventional engines ever to reach the road.