Mazda Eunos Cosmo 20B Type S

Mazda Eunos Cosmo 20B Type S

The Mazda Eunos Cosmo (JC series), produced from 1990 to 1995, holds a unique place in automotive history as the only production car ever equipped with a triple-rotor Wankel rotary engine. The 20B-REW — a 2.0-litre sequential twin-turbocharged three-rotor powerplant — represented the pinnacle of Mazda's rotary engine technology and remains one of the most exotic powertrains ever offered in a production automobile.

The Eunos Cosmo was part of Mazda's ambitious multi-brand strategy of the early 1990s, sold through the premium Eunos channel (alongside the Eunos Roadster, which was the JDM version of the MX-5). It was conceived as a luxury grand touring coupe that would showcase Mazda's most advanced technology — not just the triple-rotor engine but also the world's first GPS satellite navigation system with a built-in touchscreen CRT display, a feature that was years ahead of any competitor.

The 20B-REW engine was the crown jewel. Adding a third rotor chamber to the proven 13B twin-rotor architecture increased displacement to 1,962cc (each rotor displacing 654cc) while maintaining the Wankel engine's inherent smoothness and compact dimensions. Sequential twin turbocharging — where a smaller turbo provides boost at low RPM before the larger turbo takes over at higher speeds — addressed the rotary engine's traditional weakness of limited low-end torque. The result was 300 PS at 6,500 rpm and 300 lb-ft of torque at 3,000 rpm — the maximum permitted under the Japanese gentlemen's agreement.

The 20B's power delivery was unlike anything else in production. The sequential turbo system provided remarkably smooth boost progression, while the rotary engine's inherent smoothness (with no reciprocating mass) created a turbine-like power delivery that seemed to pull harder the higher it revved. The sound was unique — a high-pitched, almost musical whirr quite different from any piston engine.

The Eunos Cosmo was only available with a four-speed automatic transmission — a decision that disappointed some enthusiasts but reflected the car's grand touring intent. The automatic was a sophisticated electronically controlled unit, but the lack of a manual option has remained the car's most-discussed limitation.

The body was a large, elegant two-door coupe with pop-up headlights, a long hood, and generous proportions that reflected its grand touring mission. The cabin was luxuriously appointed with leather, wood trim, and the groundbreaking CCS (Car Communication System) touchscreen that controlled navigation, climate, and audio functions — technology that would not become commonplace for another 15 years.

The Eunos Cosmo was never exported, remaining a Japan-domestic-market exclusive throughout its production run. Total production was approximately 8,875 units, of which the triple-rotor 20B-equipped Type S and Type E accounted for the majority. A twin-rotor 13B-REW version (identical to the RX-7 FD engine) was also available as the Type SX.

Today, the Eunos Cosmo is one of the most collectible Japanese cars of the 1990s, valued for its technological significance, rarity, and the unique triple-rotor engine that was never used in any other production car. Finding a well-maintained example is challenging, as the 20B engine requires knowledgeable specialist maintenance and fuel consumption is prodigious.