When the average punter thinks of iconic '90s Japanese cars, a Nissan Skyline, Toyota Supra, or even a Subaru Impreza WRX and Mitsubishi Lancer Evolution frequently come to mind.
All these models have a serious heritage for catapulting this Asian country's auto industry from boring economy cars to something that could have real sporting gains.
However, one Mazda branded under Eunos has undeservingly been forgotten – the JC Cosmo, a car that was born before the world was ready for it.
The beginning of the Eunos Cosmo
Reaching the international market for the luxury Japanese sector didn't go too well – sure, Toyota was seeing success with Lexus, but Mazda wanted a similar rebrand.
As our Features Editor, Rob Margeit, explored in his recent flashback, Mazda's answer was to relaunch under the Eunos series of 'luxury' cars, built under Mazda but with its own brand identity.
Long story short, the pricing was expensive, the equipment you got with the cars was average, and the styling of the models was not ideal. The resulting financial fallout, combined with the black hole Japan's economy was mired in at the time, almost killed the Mazda brand.
The front-wheel-drive V6 line of cars we received in Australia, best described as second-best to what was on sale in the US domestic market, just didn't tickle anyone's fancy. However, some of the vehicles that the Japanese market got were incredible.
One of those vehicles was the JC Cosmo. Technically, the first-generation Eunos Cosmo, but really the fourth-generation Mazda Cosmo, it was the most mechanically and technologically advanced car to ever come out of the Mazda factory and, I dare say, the most advanced Japanese car at the time.
The nameplate dates back to 1967, when the L10A Cosmo was born, and goodness me was it a gorgeous car. While it was entirely designed in-house, the first-generation Cosmo echoed shapes from the Lotus Elan, Jaguar E-Type, and Alfa Romeo Spider, all wrapped into one.
The Cosmo wasn't built to break sales records or be a car you happen to just stumble across and fall in love with at the dealership. It was what was called a 'halo car'. These types of vehicles, while sold to the public, are built to showcase a manufacturer's abilities, much like clothes in a runway fashion show.
Further extending the halo car appeal, Mazda equipped the Cosmo with an experimental engine design from Germany – the Wankel Rotary.
Mazda improved the German design and found a way to make tandem rotors reliable, which catapulted the rotary engine to become the face of the Mazda brand and overshadowed Felix Wankel as its inventor.
The Cosmo went through two more generations, which, while beautiful in their own right, didn't fit the halo car ideal and were sold as the Mazda 121 and Mazda 929 in Australia with a piston engine instead of the rotary.
When the mid-'80s rolled around, Mazda needed a new halo car to kick off its Eunos brand. At the 1985 Tokyo Motor Show, the Japanese marque dropped the covers on the MX-03 concept.
This radical design featured a space-age interior and something that had never been heard of – a tri-rotor engine – an engine produced for the late 727c and 757 endurance prototype racing cars.
The response was a mixture of shock and excitement, but it still paved the way for the production of the Eunos JC Cosmo – Eunos's halo car.
Before we get into the space-age interior and gorgeous styling of the production JC Cosmo, perhaps the most interesting thing is that it sported the only production three-rotor engine ever – the 20B.
Increasing the engine's capacity over the two-rotor 13B, found in previous Mazda models, helped what was a plague of the rotary – a lack of low RPM grunt. The 20B saw an increase of torque by over 100Nm and sported nearly 300hp (224kW) in production form.
The 20B was a marvel of engineering beyond that of the famous four-rotor found in the 787B Le Mans car because it was a production engine. Rotary engines are an inherently flawed design due to their frictional vibrations and balancing struggles that cause uneven wear, unlike a piston engine which slides up and down in cylinder, and can be easily balanced.
With each rotary housing added, the risk of catastrophic engine failure increases. That's all well and good when you have a race engine that is stripped and rebuilt every few races, but a production engine that needs to last for decades, that's another story. Yet some engineering tricks made the three-rotor 20B right at home in a production car.
Oh, and you can't forget the fact that Eunos strapped sequential turbos onto the engine: one that gave the engine a slightly low RPM boost, and one that blasted the engine with extra power in the top end.
The forced induction went beyond the power too. The twin-turbo set-up allowed the Cosmo to have a linear and smooth power application all the way to redline – essentially, the power didn't taper off; it kept going.
This wonder of an engine was mated to an electronically controlled four-speed transmission (not available in a manual) and sent all that rotary power to the rear wheels. Some trick suspension components, like a multi-link rear arm set-up, complete the amazing mechanical engineering.
Where the Cosmo continued to shock was the interior. Among the small cattle farm worth of leather packed inside was a ground-breaking infotainment system – a touch-screen CRT colour screen handled the climate control, while a car phone, a TV and a multi-disc CD player completed the interior.
Packed into that CRT screen was the first ever built-in GPS navigation system ever factory fitted to a vehicle; a trend that wouldn't fully take off for almost another decade.
By definition, the Eunos Cosmo was what a grand tourer should be: a beautiful coupe mixed with luxury that the British royal family wouldn't turn their noses up at, with power and an individual engine and performance that somehow tied in with comfort.
It had a total of 8875 sales across its 1990–1996 lifespan and marked the death of the Cosmo nameplate, but why did it flop?
Why was the Eunos Cosmo a flop?
The Eunos Cosmo fell on its own sword because it was simply too far ahead of its time. Being stacked with engineering and technological marvels came at a price.
The "Sport" 13B two-rotor Cosmo started at about ¥4 million (exchange rate at that time would make it $AUD42,000), and if you wanted the top of the range "Elegant" 20B three-rotor, it would run you ¥5.3 million (around $AUD57,000 at the time).
Adjusted for inflation, that's $138,000 for the top spec in 2025 money. That price tag actually makes it the most expensive car Mazda has mass-produced ever. Compare this to the sticker price of the top-of-the-line Spirit R RX-7 FD of ¥3.9 million, which really puts it into perspective.
Plans to sell the car in the US under Amati (what was supposed to be the Eunos equivalent in North America) fell through, and the car was simply too expensive for international markets with additional import costs and taxes (for example, the FD RX-7 had a sticker price of $AUD89,505 in Australia –double that of the Spirit R special edition RX-7 in Japan).
Not to mention the fact that the 20B engine drank a claimed 16L/100km in fuel during a time when pressure was on to start making more economical cars.
Sure, the Eunos didn't even manage to reach 10,000 sales, but that's not necessarily a flop in the books of what the car was supposed to do.
As I mentioned previously, the Cosmo was an example of what the brand could do, not something intended to sell in big numbers. But the Eunos brand flopped so hard that Mazda had to be dug out of the grave by Ford in 1996, thus making the Cosmo a flop by association.
It's a real shame. It could've been one of the greats, and examples are only getting rarer as rotary enthusiasts pillage these cars for their 20B engines. They have since become a popular personal import option, with the JC Cosmo selling for between $30,000 and $60,000 in the used market in Australia depending on the trim level.
Zane Dobie comes from a background of motorcycle journalism, working for notable titles such as Australian Motorcycle News Magazine, Just Bikes and BikeReview. Despite his fresh age, Zane brings a lifetime of racing and hands-on experience. His passion now resides on four wheels as an avid car collector, restorer, drift car pilot and weekend go-kart racer.
