Description
The Mazda Xedos 9 Miller was the flagship and most technologically ambitious version of the Xedos 9 range, and one of Mazda’s most interesting engineering achievements of the 1990s. Sold mainly in Japan (as the Eunos 800/ Mazda Millenia) and in selected export markets, the Miller variant used an advanced Miller-cycle V6 engine equipped with a belt-driven positive-displacement compressor. This gave the car the performance of a larger-capacity luxury saloon while maintaining the fuel economy and refinement of a smaller engine. It was the first production car in the world to use a Miller-cycle petrol engine, making it an important milestone in Mazda’s engineering history.
Power came from Mazda’s 2255 cc KJ-ZEM V6, a compact 24-valve engine producing around 210 horsepower. Instead of relying purely on displacement, Mazda used an ingenious combination of delayed intake valve closing and a Lysholm-type compressor to improve both efficiency and power. The result was smooth, linear acceleration and an unusual blend of torque-rich response and high-rev refinement. The engine felt effortless at low speeds and impressively flexible when overtaking, behaving more like a 3.0-litre V6 despite its smaller capacity. A four-speed automatic transmission was fitted as standard, tuned for seamless, quiet shifts in keeping with the car’s executive character.
The chassis shared the refined fundamentals of the wider Xedos 9 family. Fully independent suspension — MacPherson struts at the front and a multi-link arrangement at the rear — gave the car a supple, composed ride. Mazda tuned the Miller variant for smoothness and stability, prioritising quiet long-distance comfort rather than sporting performance. Steering was light but precise, and the car maintained a calm, settled feel at motorway speeds. The additional torque from the Miller engine complemented the chassis well, giving the car a more confident and relaxed high-speed character than the 2.0 or 2.5 V6 versions.
Styling followed Mazda’s elegant, understated Xedos philosophy: smooth lines, minimal ornamentation and a cohesive, aerodynamic shape free from aggressive edges. Subtle chrome accents and carefully sculpted surfaces gave the car a mature, premium presence. The Miller version looked almost identical to the regular Xedos 9, which was intentional — Mazda wanted luxury through refinement, not flamboyance. The proportions were dignified, the profile was sleek and the overall design has aged remarkably well.
Inside, the Xedos 9 Miller offered one of Mazda’s most refined cabins of the era. The dashboard layout was symmetrical and uncluttered, with soft-touch materials and excellent build quality. Seats were wide, deeply cushioned and designed for long-distance comfort. High-spec Miller models typically included automatic climate control, leather upholstery, wood-tone trim, high-quality audio systems, electric seats and generous sound insulation. Rear passengers enjoyed excellent legroom thanks to the long wheelbase, and the cabin ambience was quiet, calm and deliberately luxurious. This was a car designed for relaxed travel rather than overt sportiness.
On the road, the Xedos 9 Miller delivered a refined, quiet and effortlessly smooth driving experience. The Miller-cycle V6 provided strong mid-range power and relaxed cruising ability without the thirst normally associated with performance engines. At motorway speeds the engine turned quietly and smoothly, and the suspension absorbed imperfections with a calm maturity. The car felt composed and stable, and although not intended for aggressive driving, its balanced chassis and precise steering gave it reassuring road manners. The Miller version excelled at quiet, long-distance travel, combining efficiency with a distinctly premium feel.
The Mazda Xedos 9 Miller represented the peak of Mazda’s 1990s luxury engineering and its most innovative powertrain project. It demonstrated Mazda’s ability to combine technical ingenuity with refinement and understated elegance. While sales numbers were modest, the Miller-cycle engine remains one of the brand’s most significant achievements, influencing later approaches to efficiency and forced induction.
Today the Xedos 9 Miller is extremely rare and highly appreciated among enthusiasts who value Mazda’s engineering history. Its smooth, unusual power delivery, elegant styling and refined interior make it one of the most distinctive Japanese executive cars of its era. As a showcase of Mazda’s technical imagination, the Xedos 9 Miller stands as one of the company’s most intriguing and sophisticated luxury cars.