RX-Rated: Mazda’s Early Rotary Cars, Part 1

Mazda has a long history with rotary engines, going back to the Cosmo Sport and R100 of the late 1960s. With the recently announced demise of the RX-8 — the last rotary-engined model still in production — we look back at the origins of the Wankel engine and the history of the early Mazda rotary engine cars: the Mazda Cosmo Sport 110S, Familia Rotary (Mazda R100), and Luce Rotary Coupé (R130).
1971 Mazda R100 coupe badge


The company we now know as Mazda dates back to the January 1920 formation of Toyo Cork Kogyo Co. Ltd. (roughly, “Oriental Cork Industrial Company”) in the Japanese city of Hiroshima. The company’s initial business, the manufacture of synthetic cork products, soon fell on hard times, and in early 1921, its creditors appointed a new president, 45-year-old Jujiro Matsuda, a fisherman’s son and one-time blacksmith’s apprentice who had previously founded his own firearms company, Matsuda Works.

Matsuda took Toyo Cork Kogyo in new directions, including the manufacture of machine tools and a brief stab at building motorcycles. By 1927, the cork business had been abandoned, and the company’s name became simply Toyo Kogyo Co. Ltd.

In 1931, Toyo Kogyo introduced its first successful motor vehicle: the Mazda-GO DA Type truck, a three-wheeled, cargo-carrying motorcycle powered by a 500 cc (30 cu. in.) engine. The “Mazda” trademark, also used by General Electric for a brand of light bulbs, was selected primarily as an alternative transliteration of “Matsuda,” but it also meant “wisdom” in the ancient Avestan language of the Zoroastrian religion, most commonly associated with the supreme Zoroastrian deity, Ahura Mazda (Lord of Wisdom).

Initially distributed by Mitsubishi, the little Mazda three-wheeler sold well both before and after World War II, spawning several follow-on models and eventually the company’s first four-wheeled truck, launched in 1950. While Jujiro Matsuda had contemplated building automobiles around 1940, the war and subsequent reconstruction tabled those plans and Toyo Kogyo did not offer its first passenger vehicle until 1960.

Like many early Japanese automobiles, the initial Mazda R360 Coupe was a tiny kei car powered by an air-cooled V-twin engine, not vastly different from the motorcycle-engined European “bubble cars” of the time. Nonetheless, the R360 and the subsequent four-seat Mazda Carol, introduced in 1962, were quite successful in the growing Japanese market, briefly making Mazda Japan’s best-selling automotive marque.

1964 Mazda R360 Coupe front 3q copyright 2010 Rex Gray (CC BY 2.0 Generic) modified by Aaron Seversno
A 1964 example of the Mazda R360 coupe, Toyo Kogyo’s first passenger car. Launched in 1960, it was powered by a 356 cc (22 cu. in.) air-cooled two-cylinder engine with 16 hp (12 kW). Since the R360 weighed less than 900 lb (about 400 kg), that was enough for a top speed of around 55 mph (90 km/h). At introduction, the R360 cost only ¥300,000, equivalent to about $835. A four-cylinder model, the Mazda Carol, followed in 1962. The R360 was discontinued in 1966, but the Carol survived through 1972. (Photo: “1964 Mazda R360 Coupe” © 2010 Rex Gray; resized and modified (obscured bystander faces) 2011 by Aaron Severson and used under a Creative Commons Attribution 2.0 Generic license, with this modified version offered under the same license)

Despite that success, Toyo Kogyo faced a more serious long-term threat to its existence. While the Japanese economy was expanding rapidly, the domestic auto industry was still quite small and very vulnerable. With considerable diplomatic pressure to relax import restrictions, Japan’s Ministry of International Trade and Industry (MITI) was contemplating drastic measures to protect native industry from a potential flood of foreign-made cars. One rumored possibility was a consolidation of domestic automakers into as few as three or four major conglomerates, an alarming prospect to smaller companies like Toyo Kogyo, which under such a plan would either disappear or be absorbed into larger automakers like Nissan or Toyota.

Jujiro Matsuda’s son Tsuneji, who had succeeded his father as president in 1951, decided that the only way for Toyo Kogyo to survive as an independent company was to offer products or technology that rivals could not match. Cars like the R360 and Carol were competent efforts, but they were fairly conventional. For the company to have a future, Mazda needed something unique.


Matsuda found his answer two continents away, at NSU-Motorenwerke in Neckarsulm, Germany, which had recently announced a novel new rotary engine co-developed by NSU and independent engineer Felix Heinrich Wankel.

Although Felix Wankel’s name is still closely linked with the rotary engine, it was not a new idea even when Wankel first started working on it in the 1920s. Plans and patents for rotary steam engines had been developed as far back as 1769, although it’s unclear if they were ever built or would have worked if they had been built. Wankel’s own interest in rotary internal combustion engines had begun when he was only 17 years old, stemming from a dream he once had about a car powered by an engine combining the best attributes of piston engines and turbines. He patented his first rotary engine in 1934 while pursuing a related idea, rotary valves for piston engines. Wankel was subsequently commissioned by the German air ministry to apply the latter concept to aircraft engines, work that led to his arrest and a brief imprisonment after the war. He was released in 1946 and eventually resumed his work at a new research lab in the Bavarian city of Lindau.

Felix Wankel 1950s copyright Mazda
Felix Wankel, circa the late 1950s. (Photo circa 1958, copyright and courtesy Mazda)

In 1951, Wankel signed a consulting agreement with NSU to develop rotary valves for motorcycle engines, later followed by a rotary supercharger. (NSU had made automobiles before the war, but sold its auto business to Fiat in 1929 and did not return to passenger car production until 1957.) However, Wankel remained eager to develop a true rotary engine and lobbied strenuously for NSU to underwrite the project. At first, the NSU board was not overly enthusiastic, but by 1954 Wankel had persuaded company management to share the development costs and any patents related to the new engine.

The engine that we now think of as the Wankel rotary was actually a substantial departure from Wankel’s initial early-fifties concept, the Drehkohlbenmotor (DKM, rotary-piston engine). Developed mostly in Lindau by Wankel and his research partner, Ernest Höppner, the DKM featured a trochoidal (triangular) inner rotor with a spark plug set into one face. Both the inner rotor and the rotor housing (sometimes described as an outer rotor) spun around a common stationary center shaft with the combustion process taking place between the two rotating bodies.

DKM prototypes, which first ran in 1957, had excellent volumetric efficiency — particularly considering that the intake charge had to be routed through the center shaft and inner rotor — and could sustain very high speeds with almost no vibration. From a practical standpoint, however, the DKM left much to be desired. Low-speed performance was poor and high rotational inertia made the engine reluctant to change speeds, problematic for anything other than stationary applications. Furthermore, the transmission or output shaft had to be geared to the outer rotor/rotor housing, which was inconvenient from a packaging standpoint. Changing spark plugs required tearing down the entire engine.

1957 Drehkolbenmotor DKM54 stand copyright 2005 Ralf Pfeifer at German Wikipedia (CC BY-SA 3.0 Unported)
Felix Wankel’s first running prototype Drehkohlbenmotor, the DKM 54, photographed at the Deutsches Museum in Bonn in 2005. (Photo: “DrehkolbenmotorDKM54” © 2005 Ralf Pfeifer at German Wikipedia; resized 2011 by Aaron Severson and used under a Creative Commons Attribution-ShareAlike 3.0 Unported license)

Recognizing those problems, NSU research chief Walter Fröde pushed for an alternative design, the Kreiskolbenmotor (KKM, circuit piston engine), which first ran in mid-1958. In Fröde’s KKM design, a trochoidal inner rotor drove the output shaft via cycloidal gears, causing the rotor to trace an epitrochoidal path (a shape often compared to a peanut or a cocoon) along the inner surface of the rotor housing (see the sidebar on the next page), which unlike in the DKM remained stationary. This approach sacrificed some of the DKM’s smoothness and rev potential as well as posing certain challenges for cooling, but offered much better low-speed behavior and was vastly easier to install and maintain. Wankel was unhappy with the KKM, considering it a cheapening of his concept, but the practical advantages were hard to ignore. The NSU board made it clear that the cash-strapped company could not afford two different rotary designs, so Fröde eventually persuaded Wankel to abandon the DKM.

Even so, the rotary project was a big gamble for NSU, and the Neckarsulm firm lacked the resources to fully develop or exploit the new engine on its own. With prototypes running on test stands, NSU started looking for partners and licensees to share the work and the cost. The first was the American aviation company Curtiss-Wright, which in October 1958 paid a reported $2.1 million (plus a 5% per-engine royalty) for exclusive, sublicensable U.S. rights. Over the next few years, NSU would receive more than 100 other license requests covering everything from lawnmower engines to heavy-duty diesel applications.

When Tsuneji Matsuda heard about the rotary engine in late 1959, he concluded that it was exactly what Toyo Kogyo needed. The rotary was mechanically elegant, had great potential, and was radically different from anything else on the road. Matsuda made initial overtures in early 1960 and visited Neckarsulm with a group of engineers that October to see NSU’s development engines and negotiate the licensing agreement. MITI approved the deal in mid-1961. The reported license fee was ¥280 million (about $780,000 at the contemporary exchange rate).

The agreement gave Toyo Kogyo the right to use and sell the rotary engine in Japan and Asia. All they had to do now was make it work.


As elegant and straightforward as it seemed on paper, Toyo Kogyo engineers quickly discovered that the rotary engine had many serious problems. At the time the license agreement was approved, even NSU had yet to build a truly production-ready engine, and the early single-rotor prototypes suffered a very rough idle and prodigious oil consumption. Cooling was also problematic and the gap in the water jacket around each spark plug housing produced thermal stresses that would eventually crack the rotor housing.

The biggest problems, however, were with the complex apex and corner seals at each rotor tip. Those seals were responsible for maintaining compression and segregating exhaust gases from the intake charge, but they experienced considerable stress from the combustion process, limiting their useful life. When the seals wore out, the engine suffered dramatic power loss. Few of the early tip seals had anything approaching an acceptable lifespan, usually failing after less than 200 hours of operation. Harder materials lasted longer, but exacerbated another problem: the tendency of the apex seals to leave vicious “chatter marks” on the inner surface of the rotor housing. During the first two years of development, Toyo Kogyo reportedly scrapped hundreds if not thousands of ruined test engines.

Although the Japanese engineers were progressing more quickly than their NSU counterparts were in some areas, the development process was undoubtedly expensive, and Toyo Kogyo might well have given up had it not been for the determination of Tsuneji Matsuda. The story among company employees was that the normally implacable Matsuda had actually kowtowed before Toyo Kogyo’s principal financiers while pleading for the resources to continue the rotary project. Whether or not that was true, Matsuda made it clear that he considered the rotary the key to the company’s survival — a commitment that eventually won over even one of the engine’s harshest internal critics, engineer Kenichi Yamamoto.

Yamamoto, born in Kumamoto in September 1922, had received a degree in mechanical engineering in 1944 from the prestigious Imperial University in Tokyo. Conscripted after graduation, he had been commissioned as a naval lieutenant and sent to work with Kawanishi Aircraft at the firm’s naval works in Tsuchiura, where he was eventually assigned to work on kamikaze aircraft. When the war ended, jobs for skilled engineers were scarce, so Yamamoto ended up as an assembly line worker at the Mazda plant in Hiroshima, which had only recently reopened after being damaged in the American atomic attack. Yamamoto’s articulateness and technical drawing skills (which he had continued to practice) did not go unnoticed, however, so a few years later he was transferred him to engine development, working on the design of Toyo Kogyo’s first OHV engine.

early Wankel engine copyright Mazda
An early rotary engine, possibly a single-rotor NSU engine. In this view, the rotary’s compact dimensions are readily apparent. The engine itself is dwarfed by its air cleaner and carburetor, gearbox, and accessories. (Photo circa early 1960s, copyright and courtesy Mazda)

By his own account, Yamamoto was not pleased when the company licensed the rotary engine in 1961. He considered the rotary conceptually sound, but he was all too aware of the many pitfalls facing any new engine design and saw the whole project as a boondoggle and a waste of resources. Given those doubts, one can imagine his reaction when he learned in April 1963 that he had been reassigned to lead the new Rotary Engine Research Department.

Yamamoto’s first six months in his new job did little to assuage his doubts. Despite the dedication of his hand-picked engineering team, known internally as the “47 Ronin” (in reference to the famous group of masterless samurai whose quest to avenge their fallen lord in the early 1700s is popularly regarded in Japan as the epitome of honor, loyalty, and duty), the rotary engine’s major problems seemed intractable — particular the chatter marks, whose cause was initially elusive. Nonetheless, Yamamoto resolved to give it his best effort, particularly after he heard Matsuda deliver a speech to Toyo Kogyo suppliers that June, outlining the existential threat posed by MITI’s consolidation plans.

By the time Toyo Kogyo exhibited prototypes of the new rotary at the Tokyo Auto Show in October, Yamamoto had become so frustrated and discouraged that he told Matsuda he wanted to resign. Matsuda persuaded him to stay by appealing not only to Yamamoto’s company loyalty, but also to the memory of the siblings they had both lost in the bombing of Hiroshima.

Matsuda rewarded Yamamoto’s perseverance with an infusion of new resources. In 1964, Toyo Kogyo set up a state-of-the-art rotary engine lab with 30 test cells and computers to process the test data, still a novelty in the mid-sixties. Over the next three years, the company would quadruple the size of its rotary engineering staff.

Gradually, Yamamoto and his team came to grips with the rotary’s major flaws. The chatter marks were eventually traced to the apex seals hitting their resonant frequency within the engine’s operating range, which was addressed with changes to the seal design and materials. The apex seals of Mazda’s early production rotaries were self-lubricating pyrographite, impregnated with aluminum for greater strength, which eliminated the chatter marks and provided a useful life of at least 60,000 miles (100,000 km). Meanwhile, better oil seals, developed in partnership with Nippon Oil Seal Co. and Nippon Piston Ring Co., finally reduced oil consumption to a manageable level. By 1967, Toyo Kogyo was finally ready to launch its first rotary-engine production car.


To showcase its new engine, Toyo Kogyo decided to develop an entirely new car not based on any existing model. Known internally as Project L402A and later christened Mazda Cosmo Sport, it was the first Mazda sports car: a low-slung monocoque coupe with a very low hood line that took full advantage of the rotary’s compact dimensions.

Although Toyo Kogyo had gone to Italy for some past design work, the Cosmo Sport was styled in-house, looking rather like the bonsai offspring of a 1961 Ford Thunderbird and the 1963 Chrysler turbine car. Unlike Mazda’s early kei cars, the Cosmo Sport had a front engine and rear-wheel drive. Front disc brakes were standard and the sole transmission was a four-speed manual gearbox.

1967 Mazda Cosmo Sport 110S front 3q
The early L10 Cosmo Sport was 163 inches (4,140 mm) long on an 86.6-inch (2,200mm) wheelbase, standing only 45.9 inches (1,165 mm) high. Curb weight was quoted at 2,024 lb (918 kg). The Cosmo Sport had quick rack-and-pinion steering, but some reviewers criticized it for being numb on center and complained that crosswinds response was less than reassuring. (author photo)

The earliest Cosmo Sport prototypes had a two-rotor engine known as the L8A, with a total swept volume of 798 cc (49 cu. in.). (Unlike NSU, Toyo Kogyo engineers had largely abandoned single-rotor engines, concluding that multiple rotors provided better low-end torque and idle quality. Mazda would briefly explore a return to the single-rotor concept in the 1970s in search of greater fuel economy, although they never offered a single-rotor engine in any production car.) To improve low-speed performance, the L8A had two spark plugs for each rotor, one firing 5 degrees after the other. To manage the separate advance curves for the twin plugs, there were two complete ignition systems, including twin distributors.

The first two running prototypes of the new car were finished by October 1963, and Matsuda actually drove one to the Tokyo Auto Show later that month. However, Toyo Kogyo displayed only the engines at that show, delaying the Cosmo Sport’s public debut until September 1964. According to some accounts, Matsuda opted to wait as a show of respect to NSU, whose first Wankel Spider had debuted in Frankfurt only a few weeks before the 1963 Tokyo show. According to others, NSU pressured Toyo Kogyo to delay the launch and discouraged plans to show the Cosmo Sport overseas, lest it steal the Spider’s thunder.

1967 Mazda Cosmo Sport 110S rear 3q
The Mazda Cosmo Sport had double wishbone front suspension with coil springs, but the rear was a de Dion layout with a fixed differential and a beam axle on semi-elliptical leaf springs, located by trailing links. The unassisted disc/drum brakes were adequate for the Cosmo Sport’s weight, but feel and pedal effort drew some criticism. In response, the L10B cars added a standard vacuum servo. (author photo)

Initially, the L8A had peripheral exhaust ports and a combination of side and peripheral intake ports, which linked to the primary and secondary barrels of the standard four-barrel carburetor. While the additional peripheral intake ports improved high-end power, Yamamoto’s team found them detrimental to low-speed response and idle quality and finally decided to delete them, leaving only the side intakes. That change left the L8A somewhat underpowered, so the engineers increased the rotor diameter, raising total swept volume to 982 cc (60 cu. in.). With a single Zenith-Hitachi four-barrel carburetor, the revised L10A engine was rated at 110 PS (108 hp, 81 kW) at 7,000 rpm, with a maximum of 96 lb-ft (130 N-m) of torque at 3,500 rpm.

Toyo Kogyo built about 60 preproduction cars for evaluation in 1965 and 1966, but the Cosmo Sport didn’t actually go on sale until May 30, 1967. It was not only the first production Mazda with a rotary engine; it was the world’s first two-rotor production car, debuting more than four months before NSU’s Ro80 sedan. (Curtiss-Wright had previously tested its two-rotor RC2-60 U5 engine in a modified Ford Mustang, but that engine was never offered for public sale.) Since Toyo Kogyo had only recently revised its license agreement to allow sales of the rotary engine outside Japan, the Cosmo Sport was initially offered only in the home market, with a starting price of ¥1,480,000 (around $4,100). Only a few cars ended up overseas, many of them purchased by other automakers or rotary licensees like Curtiss-Wright, who were eager to figure out what made the Cosmo tick.

1967 Mazda Cosmo Sport 110S L10A engine 1
The yellow, single-snorkel air cleaner marks this as a 110 PS (81 kW) L10A Cosmo Sport; the more powerful L10B had a blue air cleaner with twin snorkels. In either form, the 982 cc (60 cu. in.) engine was very compact and the use of cast aluminum for both the rotor housing and side housings kept dry weight to only 225 lb (102 kg), a full 90 lb (41 kg) lighter than Volvo’s comparably powerful B18 four. Note the twin distributors and ignition coils, common to most Mazda rotaries until 1974. (author photo)

The curious foreign journalists who had the opportunity to test the Cosmo Sport were mostly impressed. It handled well, with quick steering and basically neutral balance, but the real star was the engine. The L10A was not especially quiet (although some reviewers found its exhaust note quite charming), but it was exceptionally smooth and would rev to 8,000 rpm with an alacrity and enthusiasm alien to most contemporary reciprocating engines. Low-end torque was not abundant, but as engine speeds increased, performance brightened considerably. Reaching 60 mph (97 km/h) took less than 9 seconds and advertised top speed was 115 mph (185 km/h), impressive for a small sports car of the era, and faster than many V8-powered American sedans.

The Cosmo Sport was not sold in large numbers — only 343 were built between May 1967 and September 1968 — nor was it intended to be. Its construction involved a great deal of hand labor, and it’s hard to imagine Toyo Kogyo made any money on it. If the little Mazda coupe was not a profitable exercise, however, it was an effective proof of concept that drew attention from around the world, including many markets the company had yet to enter.

Even more attention came in August 1968, when Toyo Kogyo entered two Cosmo Sports in the Marathon de la Route endurance race at the Nürburgring. The Nürburgring cars had various engine modifications, including the restoration of the L8A’s auxiliary peripheral intake ports, but were otherwise close to stock. One car was felled by a broken axle during the race, but the other took fourth place, the first flush of a long and often illustrious competition career for Mazda rotaries.

Mazda Cosmo Sport on test track (ID 0255s) copyright 1968 Mazda
The revised Mazda Cosmo Sport on a test track (possibly at Toyo Kogyo’s own Miyoshi Proving Grounds), pursued by what looks to be a new Mazda Familia Rotary Coupé. (Photo circa 1968; copyright and courtesy Mazda)

In September, Toyo Kogyo introduced an updated Cosmo Sport known as the L10B. While engine displacement was unchanged, porting, carburetion, and intake modifications boosted the 982 cc (60 cu. in.) engine to 130 PS (128 hp, 97 kW), comparable to the Nürburgring cars. Externally, the L10B looked little different than before, but the front wheels were moved forward 5.9 inches (150 mm), increasing wheelbase to 92.5 inches (2,350 mm); overall length was actually slightly reduced. (We don’t know the rationale for the change, but it may have been an effort to improve ride quality.) Meanwhile, the gearbox acquired an overdrive fifth gear; a vacuum servo was added to the brakes; the wheels were enlarged to 15 inches (381 mm); and air conditioning was newly optional, mounted on the shelf behind the front seats.

The changes added about 110 lb (50 kg) to the Cosmo Sport’s curb weight, but with the added power, the L10B was even faster than before, with an advertised (and probably conservative) top speed of 124 mph (200 km/h). The revised Cosmo was more expensive as well, with base price rising to ¥1,580,000 (a bit under $4,400 at the contemporary exchange rate). Although the L10B was once again offered only with right-hand drive, a few were officially exported. It appears that most export models used the earlier engine and four-speed gearbox and carried the “110S” identification of the L10A cars.

1967 Mazda Cosmo Sport interior (ID 204) copyright 2007 Mazda
Despite its rocket ship exterior styling, the interior of the Mazda Cosmo Sport (here an early L10A, with four-speed gearbox) was refreshingly no-nonsense, featuring full instrumentation and somber black trim, leavened with a wood-rimmed steering wheel and then-fashionable houndstooth check upholstery. (Photo circa 2007, copyright and courtesy Mazda)

The L10B remained in limited production through the 1972 model year. The Cosmo received a bit of extra publicity in 1971, when the car was featured on the television series Return of Ultraman, and at least one Cosmo Sport was used as a highway interceptor by the Hiroshima Prefecture Police into the mid-1970s. However, the L10B was expensive for the Japanese market, and sales rarely topped 200 units a year. The final production tally was 1,176, not including the earlier L10A models.

The Cosmo Sport was an interesting exercise, but it was really only a prelude to Toyo Kogyo’s biggest gamble: the first mass-market Mazda rotary.


In November 1967, Toyo Kogyo began rolling out the second generation of its compact family car line, the Mazda Familia, originally launched in 1963–1964. The Familia was rapidly becoming the company’s volume product, and the new version was the first model slated for export in meaningful numbers. At launch, the Familia was offered only with four-cylinder piston engines, but at the Tokyo Auto Show that fall, Toyo Kogyo exhibited a rotary version of the new coupe, identified as the RX-85 and powered by a detuned version of the Cosmo Sport’s 982 cc (60 cu. in.) two-rotor engine.

1968 Mazda Familia Rotary Coupe R100 front 3q copyright 1968 Mazda
An early press photo of the 1968 Mazda Familia Rotary Coupe (officially styled “Rotary Coupé”). The rotary-engined Familia, known as R100 in some export markets, was 150.8 inches (3,830 mm) long on an 89-inch (2,260mm) wheelbase. Shipping weight was 1,775 lb (805 kg), rising to 2,010 lb (912 kg) with a full tank of fuel. (Photo circa 1968, copyright and courtesy Mazda)

The production RX-85, now dubbed Mazda Familia Rotary Coupe, arrived in July 1968. To reduce production costs, its 10A engine used cast iron side housings and traded the Cosmo Sport’s chrome-molybdenum eccentric shaft for a cheaper chrome steel unit. With revised porting and carburetor settings, output dropped to 100 PS (99 hp, 75 kW) and 98 lb-ft (132 N-m) of torque, still a healthy improvement on the 59 PS (58 hp, 43 kW) of the Familia 1200’s 1,169 cc (71 cu. in.) SOHC four. In other respects, the rotary car was very much like the Familia 1200, with a four-speed gearbox, MacPherson struts, and a live axle on semi-elliptical springs. Early production models even retained the same 10.6 U.S. gallon (40 liter) capacity as the 1200, although on later rotary Familia models, the fuel tank was enlarged to 13.2 gallons (50 liters) to compensate for the rotary engine’s greater thirst.

Starting at ¥660,000 (around $1,840), the Rotary Coupe was significantly more expensive than a piston-engined Familia, but also a great deal faster. Toyo Kogyo advertised a top speed of 112 mph (180 km/h) and 0-400 meter (approximately a quarter mile) acceleration in 16.4 seconds; 0-62 mph (0-100 km/h) times were around 11 seconds. Independent testers outside Japan found those figures somewhat optimistic, but the rotary Familia still had brisk performance, and there were few other street engines of that time that could happily run to 7,000 rpm. The trade-off was fuel economy. The Familia Rotary’s thirst was not outrageous — in the neighborhood of 20 mpg U.S. (11.8 L/100 km) overall — but it was more comparable to that of six-cylinder engines than of the small fours offered elsewhere in the line. Buyers who expected fuel consumption in line with the 10A’s geometric displacement were to be sorely disappointed, something that would become the rotary engine’s bête noire.

1971 Mazda R100 coupe dash
The well-appointed interior of a Familia/R100 Rotary Coupé. This LHD car is a 1971 U.S. model. (author photo)

1971 Mazda R100 coupe fender badge
The Mazda Familia name was not widely used overseas. Piston-engined export models were generally badged “Mazda 1200,” while the rotary versions were christened Mazda R100. (author photo)

Initial sales of the Mazda Familia Rotary Coupe were modest, amounting to only 6,925 units in 1968. In mid-1969, Toyo Kogyo added a four-door sedan, the Mazda Familia Rotary SS (presumably for “sport sedan”), with a base price of ¥638,000 (about $1,775), and began exporting the rotary models to Australia and Thailand. Sales expanded to Europe in the spring of 1970.

The Mazda Cosmo Sport’s Nürburgring exploits had apparently whetted Toyo Kogyo’s appetite for competition, because the company entered a Familia Rotary Coupe in the Singapore Grand Prix in April 1969, fitted with a 195 hp (145 kW) racing version of the 10A engine. The car won its class, the Familia Rotary’s first racing victory. Three more cars, detuned to a still-robust 187 hp (139 kW), entered the Spa-Francorchamps 24 Hour in Belgium that August, taking fifth and sixth. Those cars subsequently headed to the Nürburgring for the 1969 Marathon de la Route, but only one finished the race, taking fifth overall. A Familia Rotary Coupe, tuned for 214 hp (160 kW), won the All Japan Suzuka Automobile Race in November 1969.

The following summer, Mazda R100 coupes competed in the RAC Tourist Trophy and West Germany’s Touring Car Grand Prix before taking a second shot at the Spa-Francorchamps 24 Hour, once again coming in fifth. If not a spectacular success, the racing campaign was a credible effort, and paid dividends to later privateers. Many of the pieces developed for the competition cars subsequently became available over the counter in a series of sport kits.

Toyo Kogyo took its first steps into the U.S. market in early 1970, although early sales were limited to the Pacific Northwest. The Familia was part of the initial lineup, offered either with a conventional four-cylinder engine (as the Mazda 1200, in sedan, coupe, or wagon form) or with rotary power (as the R100 coupe). With a starting price of $2,495 POE, the American Mazda R100 was $550 more expensive than the conventionally powered Mazda 1200 coupe, which had only 64 gross horsepower (48 kW) to the R100’s 100 hp (75 kW). We have no sales breakdowns for the 1970 model year, but total U.S. sales for all Mazda cars and trucks amounted to fewer than 2,500 units. Those sales would grow spectacularly over the next three years.

1971 Mazda R100 coupe front 3q
The Mazda Familia Rotary (aka Mazda R100) originally came with the 982 cc (60 cu. in.) 10A engine, which in U.S. trim was rated at 100 hp (75 kW) and 92 lb-ft (125 N-m) of torque. Substituting the larger 12A and 13B engines from later Mazda rotary vehicles is a straightforward swap, providing more power with only a very modest weight penalty. This car is now powered by a later 13B (1,308 cc/80 cu. in.) engine. (author photo)

Export sales, racing success, and the addition of the sedan brought about a healthy increase in total Familia Rotary/Mazda R100 production, which climbed from around 28,000 in 1969 to a peak of 31,328 in 1970, representing around 14% of Toyo Kogyo’s total passenger car production that year. The rotary Familia received a number of minor updates late that year, but it was now overshadowed by newer models, and sales for 1971 and 1972 dropped off substantially. The Familia Rotary models were withdrawn from Australia in late 1971, from the U.S. after the 1972 model year, and from the home market in 1973. The redesigned Mazda Familia that bowed in October 1973 was not offered with a rotary engine. Total production of rotary-engined Familia models was 95,891 units.


Alongside the RX-85 at the 1967 Tokyo Auto Show was another prototype, the Mazda RX-87, a hardtop coupe loosely based on the Bertone-styled Mazda Luce 1500, which had debuted in August 1966. The RX-87 was decidedly Italianate, looking rather like a cross between an Alfa Romeo Giulia coupe and a second-generation Chevrolet Corvair two-door hardtop.

Under the hood, the RX-87 traded the 1,490 cc (91 cu. in.) SOHC four of the Mazda Luce sedan for a new 1,310 cc (80 cu. in.) 13A rotary engine. (The 13A was not related to the later Mazda 13B engine; it had different internal dimensions, where the 13B was a straightforward development of the 10A/12A series.) Unlike the Luce, which had a conventional front-engine/rear-wheel-drive configuration, the RX-87 mounted the compact 13A longitudinally ahead of the front wheels, driving a four-speed transaxle: It was Toyo Kogyo’s first front-wheel-drive car.

1970 Mazda Luce Rotary Coupe RX-87 badge copyright 2011 Murilee Martin (used with permission)
The Mazda R130 was formally known as the Mazda Luce Rotary Coupé, but production cars, like the prototype, also wore “RX-87” badges on the rear fenders, just aft of the doors. (Photo © 2011 Murilee Martin; used with permission)

Christened Mazda Luce Rotary Coupé, or R130, the production version of the RX-87 went on sale in October 1969. The R130 was the largest passenger car Toyo Kogyo had yet offered, significantly bigger than the Luce sedan on which it was nominally based. The Rotary Coupé’s 13A engine had less power than the smaller engine in the Cosmo Sport L10B, 126 PS (124 hp, 93 kW) at 6,000 rpm, but substantially more torque: 127 lb-ft (172 N-m) at 3,500 rpm.

Like the earlier Mazda Cosmo Sport, the R130 had double wishbone front suspension (albeit with unusual rubber torsion springs rather than coils), front disc brakes, and a standard vacuum servo, but the FWD Luce’s rear suspension was independent, with coil springs located by semi-trailing arms. In keeping with its price — ¥1,450,000 (a bit over $4,000) for the base Deluxe model, ¥1,750,000 (around $4,850) for the air-conditioned Super Deluxe — the R130 was well equipped and luxuriously trimmed, with a hefty dose of sound insulation. Toyo Kogyo marketed the R130 as a personal luxury coupe rather than a sports car, but it had brisk performance and a claimed top speed of 119 mph (190 km/h).

1970 Mazda Luce Rotary Coupe front 3q copyright 2010 Jens Kramer (used with permission)
The 1969–1972 Mazda Luce Rotary Coupé was 180.5 inches (4,585 mm) long on a 101.6-inch (2,580mm) wheelbase with a curb weight of around 2,830 lb (1,285 kg) in Super Deluxe trim. Overall height was 54.5 inches (1,385 mm). The R130 was a true pillarless hardtop, with no B-pillars. (Photo © 2010 Jens Krämer; used with permission)

The Mazda R130 was offered only with right-hand drive, and we don’t believe it was officially exported, although some eventually ended up in markets like Australia and South Africa. At home, the big coupe’s size, thirst, and high prices made it very rare. Only 976 were built before production ended in 1971. In October 1972, the R130’s place in the lineup was taken by a somewhat smaller, RWD coupe version of the latest-generation Mazda Luce, sold in some markets as the RX-4.

Surprisingly, Toyo Kogyo never offered another rotary production car with front-wheel drive. The company’s next FWD Mazda model, the 1980 BD Familia (323 or GLC in other markets), was offered only with conventional four-cylinder engines.


By 1970, worldwide interest in the rotary engine had increased dramatically, with nearly every major automaker seriously considering rotary power. That November, General Motors signed a $50 million licensing agreement, joining a list of licensees that included not only Curtiss-Wright and Toyo Kogyo, but also Alfa Romeo; Daimler-Benz; Porsche; and the military vehicles arm of Rolls-Royce, which was developing an unusual rotary diesel for main battle tanks. The main attraction was no longer the rotary’s light weight, smoothness, or mechanical simplicity, but its exhaust emissions.

Photochemical smog had been a growing problem in major urban areas for years, particularly in areas like Los Angeles, which is prone to atmospheric inversion layers. In the early fifties, scientific studies had linked smog to unburned hydrocarbons (HC) and nitrogen oxide (NOx) emissions from factories and motor vehicles. The state of California established the first limits on automotive emissions in 1959, followed in 1963 by the state of New York. In 1964, the U.S. Congress gave the federal government authority to regulate air pollution at a national level. The trend was not limited to the United States. Large Japanese cities had smog problems as well and there had been debate in the Japanese National Diet throughout the decade about the possibility of automotive emissions standards.

In December 1970, the United States enacted the Clean Air Act (sometimes known as the Muskie Act, after Sen. Edmund Muskie, D-Maine), which defined stringent national limits for automotive carbon monoxide (CO), HC, and NOx emissions, slated to take effect in 1975. (California had already implemented its own standards for NOx emissions, which took effect in 1971.) In response, Japan’s Environmental Agency proposed comparable regulations for Japanese vehicles along with a phase-out of leaded gasoline.

1971 Mazda R100 coupe front
For 1971, Mazda’s fledgling U.S. operation switched to the new SAE net rating system, dropping the R100’s nominal output to 77 hp (57 kW) and 80 lb-ft (109 N-m) of torque. Like all North American Mazda rotaries, the R100 now had a thermal reactor to control hydrocarbon emissions. Federalized cars also received round headlights, as the rectangular units used in other markets were not legal in the U.S. (author photo)

In both countries, the new standards triggered a political firestorm. Many automakers insisted that meeting the proposed standards was technologically impossible, particularly the new NOx limits. CO and HC emissions could be controlled by improving combustion efficiency or with add-on equipment like air injection, but NOx was a more difficult proposition, in part because some measures that reduced HC and CO (such as running very lean mixtures) actually increased nitrogen oxide emissions.

It was in this area that the rotary engine showed new promise. As a side effect of its combustion chamber shape, high surface-to-volume ratio, and relative low thermal efficiency, the rotary had greater HC emissions than did a comparable piston engine, but those same factors contributed to much lower NOx levels. (Nitrogen oxide emissions depend in large part on combustion temperatures, which are generally lower in a rotary than in a comparable reciprocating engine.) In fact, the Mazda rotaries were among the very few engines manufactured in 1970 that could meet the 1975 NOx standards without modifications. The rotary engine’s hydrocarbon emissions, meanwhile, could be brought under control with the use of a thermal reactor, which injected air into the exhaust stream to complete the combustion process. Toyo Kogyo had already developed that technology, which was included on all U.S.-bound rotaries.

1971 Mazda R100 coupe rear 3q
The Mazda R100 coupe is relatively low, standing only 53 inches (1,345 mm) high, but has a narrow tread width — 47.3 inches (1,200 mm) in front, 46.9 inches (1,190 mm) in back — which combined with narrow wheels and rather soft suspension settings to limit its maximum cornering grip. U.S. cars got larger 145SR14 radial tires on 14-inch (356 mm) wheels compared to the 13-inch (330 mm) wheels and 6.15 x 13 bias-plies on Japanese cars, but aftermarket wheels and rubber were commonly substituted. (author photo)

As a result, Toyo Kogyo was one of only a handful of auto manufacturers in the U.S. or Japan to admit that meeting the proposed NOx standards would indeed be feasible. Company spokespeople told the press that Mazda would have an all-rotary U.S. lineup by 1975. By 1971, automakers like Ford would by knocking on Toyo Kogyo’s door, hoping to buy rotary engines for their own products. Almost overnight, the rotary — and by extension, Mazda — had gone from interesting oddball to possible savior of the auto industry.

That shift of fortune was a vindication for Tsuneji Matsuda, who had fought for the rotary through all its technical hurdles despite considerable skepticism both inside and outside the company. Sadly, Matsuda died in November 1970, and the presidency of the company passed to his son, 48-year-old Kouhei Matsuda, previously Toyo Kogyo’s executive vice president. Over the coming decade, Kenichi Yamamoto would take up his former boss’s banner as the Mazda rotary engine’s principal champion.

In part two of our story, we’ll look at Mazda’s subsequent rotary models — including the Mazda Capella/RX-2, Savanna/RX-3, Luce AP/RX-4, Cosmo/RX-5, and the unusual Mazda Rotary Engine Pickup — and chart Toyo Kogyo’s spectacular rise and fall in the mid-1970s.



The author would like to thank Jens Krämer for the use of his photos; Halie Schmidt of Hill & Knowlton, Mazda’s PR agency, for her assistance in obtaining images and information from Mazda’s archives (some of which were provided on a nifty flash drive shaped like a trochoidal rotor); and Bob Nichols for the generous loan of his camera at the show where many of the photos for this article were taken.

The title of this article was inspired by the tagline of a mid-nineties U.S.-market Mazda ad, although the original ad was for the Miata, not a rotary-engined car.

For the record, the author has never owned a Mazda rotary, but does own a Mazda3 sedan, and years ago was compensated by a marketing firm hired by Mazda for participating in a couple of owner focus groups related to that model.


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Knobloch, Fabian C. Martinez, David C. Walther, Carlos Fernandez-Pello, Al P. Pisano, Dorian Liepmann, Kenji Miyasaka, and Kaoru Maruta, “Design and Experimental Results of Small-Scale Rotary Engines,” Proceedings of 2011 ASME International Mechanical Engineering Congress and Exposition (IMECE2001/MEMS-23924), November 2001; Carl Grothmann, “First Driving Report: Japanese Wankel-Powered Car,” Popular Science Vol. 190, No. 4 (April 1967), pp. 81–84; Hans Greimel, “Mazda’s rotary engine stalled, not forgotten,” Autoweek 20 October 2010, www.autoweek. com, accessed 12 October 2011; Bill Hartford, “Mazda RX-4: What, no altimeter?” Popular Mechanics Vol. 142, No. 2 (July 1974), pp. 96, 162, and “Speed and the Single Rotor,” Popular Mechanics Vol. 147, No. 3 (March 1977), p. 198; John B. Hege, The Wankel Rotary Engine: A History (Jefferson, NC: McFarland & Company, Inc., 2001); Takeo Hoshi and Anil Kashyap, “Chapter 5.2: Toyo Kogyo (Mazda) and Sumitomo Bank,” Corporate Financing and Governance in Japan: The Road to the Future (Cambridge, MA: Massachusetts Institute of Technology, 2001), pp. 153-158; HoTWire, “Rare Car: Mazda R130,” Retro Scene Mag 4 September 2008, retroscenemag. com/ post/ Rare-Car-Mazda-R180.aspx, accessed 7 October 2011; Hiroshi Inoue, [“Giugiaro-Design Mazda S8P (First-Generation Luce Prototype)”], 11 October 2012, indexindex. jp/?paged=3/, accessed 23 September 2015; “Is the Wankel the auto engine of the future?” Changing Times: The Kiplinger Magazine Vol. 26, No. 7 (July 1972), pp. 43-48; Wanda James, “Chapter 10: Mazda Makes Its Mark,” Driving From Japan: Japanese Cars in America (Jefferson, NC: McFarland & Company, Inc., Publishers, 2007); “Japanese Car Production: Mazda” (no date, Unique Cars and Parts, www.uniquecarsandparts. com.au, accessed 3 November 2011); Dale Jewett, “Mazda marks end of RX-8 production with Spirit R edition in Japan,” Autoweek 7 October 2011, www.autoweek. com, accessed 12 October 2011; Edwin Krampitz, Jr., “Mazda 16X Rotor Dimensions and Technical Details” (22 September 2009, RotaryNews.com, rotarynews. com/ node/ view/ 1050, accessed 12 October 2011); Mike Knepper, “The Meyers Mazda,” Road & Track Vol. 25, No. 3 (November 1973), pp. 36-38; Michael Lamm, “PM Owners Report: Mazda RX-2 and RX-3: Enthralled by performance, appalled by mileage” and “Taking the mystery out of miles per gallon,” Popular Mechanics Vol. 142, No. 2 (July 1974), pp. 97-101, 162; L’Editrice Dell’Automobile LEA, World Cars 1971 (Bronxville, NY: Herald Books, 1971), World Cars 1973 (Bronxville, NY: Herald Books, 1973), World Cars 1979 (Pelham, NY: Herald Books, 1979), and World Cars 1985 (Pelham, NY: Herald Books, 1985); Jay Leno, “Mazda Cosmo Sport 110S: An Under-Appreciated Classic,” Popular Mechanics October 2009, www.popularmechanics. com/ cars/ jay-leno/ 2629006, accessed 7 October 2011; Arvid Linde, Preston Tucker & Others: Tales of Brilliant Automotive Innovators & Innovations (Dorchester: Veloce Publishing Ltd., 2011), pp. 48-52; E.F. Lindsley, “How they improved the Mazda mileage,” Popular Science Vol. 208, No. 3 (March 1976), pp. 52, 130, and “The rotary is not dead,” Popular Science, Vol. 213, No. 3 (September 1978), pp. 78- 81; Brian Long, RX-7: Mazda’s Rotary Engine Sports Car (Revised 2nd Edition) (Dorchester: Veloce Publishing Ltd., 2004); Karl Ludvigsen, “How Big Are Wankel Engines?” Hemmings Sports & Exotic Car #32 (April 2008); Peter Lyon, “Driving the Mazda Cosmo Sport: Legendary Rotary-Powered Coupe Tugs at the Heart-Strings, 40 Years On” (24 December 2010, Motor Trend, www.motortrend. com/ roadtests/ coupes/ 1012_driving_the_mazda_cosmo_sport/, accessed 9 October 2011); Madaz, “My Mazda Luce Rotary Coupe” (27 November 2007, Japanese Nostalgic Car, japanesenostalgiccar. com/ forum/ viewtopic.php?t=812, accessed 17 October 2011); Wesley Mahler, “How a Rotary Engine Works” (25-26 November 2005, Rotary Engine Illustrated, www.rotaryengine illustrated.com/ how-a-wankel-rotary-engine-works/ index.php, accessed 13 October 2011) and “Rotary Engine Porting” (15 October 2006, Rotary Engine Illustrated, www.rotaryengine illustrated.com/ porting/ peripheral-port-14.html, accessed 13 October 2011); Frank Markus, “1970 Mazda Cosmo Sport 110S: Driving Mazda’s Original ‘Hum-m-m-m-er'” (23 August 2007, Motor Trend Blog, blogs. motortrend.com/ 1970-mazda-cosmo-sport- 110s-1017.html, accessed 12 October 2011); Nate Martinez, “Mazda’s 10 Most Significant Rides” (20 May 2010, Motor Trend, www.motortrend. com/features/consumer/ 1005_mazda_10_most_significant_rides/viewall.html, accessed 19 October 2011); John Matras, Mazda RX-7 (Sports Car Color History) (Osceola, WI: MBI Publishing Company, 1994); “Mazda Heritage” (no date, Unique Cars and Parts, www.uniquecarsandparts. com.au, accessed 3 November 2011); “Mazda Magic: Fastback 2-plus-2 from Japan – with Wankel Power,” Hot Car Magazine February 1970, pp. 37-39; Mazda Motor Corporation, “Great Cars of Mazda” (no date, www.mazda.com, last accessed 25 October 2011), “History of Mazda” (no date, www.mazda. com, last accessed 17 October 2011), “Mazda Spirit: The Rotary Engine” (13 August 2007, www.mazda. com, last accessed 20 October 2011), and “Next Generation RENESIS (Rotary Engine 16X) (no date, www.mazda. com, accessed 12 October 2011); “Mazda Motorsports Milestones” [Mazda USA press release], 2004; “Mazda Luce Rotary Coupe RX-4,” Old Cars of Japan ’70, 17 May 2011, ah5243.blog72.fc2. com/blog-entry-92.html?sp, accessed 22 September 2015; “Mazda Museum” (no date, CorkSport Mazda Performance, www.corksport. com/ mazda-museum.html? currency=cad&sl=EN, accessed 9 October 2011); Mazda Performance Corner, “Racing Heritage: A Conversation with Connie” (no date, Mazdaspeed Motorsports, www.mazdausa. com, accessed 1 November 2011); “Mazda Roadpacer” (no date, Unique Cars and Parts, www.uniquecarsandparts. com.au, accessed 3 November 2011); “Mazda Rotary Pickup: A revolutionary concept!” Road & Track Vol. 25, No. 11 (July 1974); “Mazda Rx-2” (30 August 2009, African Muscle Cars, www.africanmusclecars. com/ forum/ viewtopic.php?f=39 &t=3350, accessed 9 October 2011); “Mazda RX-2,” Road & Track Vol. 22, No. 9 (May 1971), pp. 78-81; “Mazda RX3” (no date, Unique Cars and Parts, www.uniquecarsandparts. com.au, accessed 3 November 2011); David Morris, “Eunos Cosmo History” (no date, DMRH Special Vehicles, www.dmrh. com.au/ jchistory1.htm, accessed 16 October 2011), “Mazda R100 History from Down-Under” (no date, Mazda Rotary Club, mazdarotaryclub. com/ mazda_history/ mazda_r100_history/ mazda_r100_history.htm, accessed 7 October 2011), “The Quiet Achiever” (no date, DMRH Special Vehicles, www.dmrh. com.au/ hb_series2.htm, accessed 16 October 2011); “MrMazda” and “superrob” (21 February to 3 March 2011, Mazda Owners Club SA, www.mazdaownersclub. co.za/ viewtopic.php?f=2&t=6367, accessed 9 October 2011); Troy Nassar, “Chrysler South Africa in the 1970s” (no date, Allpar.com, www.allpar.com/ world/ south-africa.html, accessed 9 October 2011); “New Japanese Wankel?” Popular Science Vol. 195, No. 3 (September 1969), p. 118; Karim Nice, “How Rotary Engines Work” (29 March 2001, HowStuffWorks.com, auto.howstuffworks. com/ rotary-engine.htm, accessed 13 October 2011); Masami Nishimoto and Kenichi Yamamoto, “Winds of Change at Mazda: The Story of Half a Century,” Installments I and II, The Chugoku Shinbun, 22-23 January 1998; Jan P. Norbye, “Mazda RX2: 18 Months and 30,000 Miles on a Wankel,” Popular Science Vol. 202, No. 5 (May 1973), pp. 84-85, and “The View Down the Road,” Popular Science Vol. 201, No. 3 (September 1972), pp. 44-45, and The Wankel Engine: Design, Development, Applications, 2nd printing (Philadelphia: Chilton Book Company, 1972); Jan P. Norbye and Jim Dunne, Popular Science Vol. 201, No. 2 (August 1972), pp. 36-46; Jan P. Norbye, Jim Dunne, and Jim Davis, “PS Puts 10,000 Miles on the New Mazda: Wankel-Powered Car Proves Silent, Powerful, and Trouble-Free,” Popular Science Vol. 200, No. 1 (January 1972), pp. 83-85; Masako Osada, Sanctions and Honorary Whites: Diplomatic Policies and Economic Realities in Relations Between Japan and South Africa (Westport, CT: Greenwood Press, 2002); Minoru Ota, “The Maedas’ Touch” Zoom Zoom Magazine, Summer 2008, www.mazdausa. com, accessed 13 October 2011; Alexander Palevsky and Jay Lamm, “God of RX-7,” Sports Car International, August-September 1998 (Vol. 14, No. V); Richard Pascale and Thomas P. Rohlen, “The Mazda Turnaround,” Journal of Japanese Studies Vol. 9, No. 2 (Summer 1983), pp. 213-263; Tim Pollard, “CAR interviews Mazda design chief Ikuo Maeda (2010),” CAR 2 September 2010, www.carmagazine. co.uk, accessed 13 October 2011; Laurence Pomeroy, “Laurence Pomeroy Probes Engine Development,” Motor Trend Vol. 18, No. 2 (February 1966), pp. 22-25; “RX-2” (no date, Mazda Rotary, www.mazdarotary. net/ mazda_rx2.htm, accessed 9 October 2011); Aaron Robinson, “A Tale of Two Rotaries,” Car and Driver September 2007, www.caranddriver.com/ news/ car/ 07q3/ a_tale_of_two_rotaries-car_news, accessed 15 October 2011; “rotaRRacing,” “Mazda CD Cosmo / Rx-5 History Worldwide” (22 November 2006, AusRotary.com, www.ausrotary. com/ viewtopic.php? f=3&t=118253, accessed 16 October 2011); “rotaryking,” “R130 Luce – 13A Rotary Goodness” (9 October 2011, AusRotary.com, www.ausrotary. com/ viewtopic.php? f=31&t=153800, accessed 28 October 2011); David Scott, “Has Japan Grabbed the Lead in Wankel-Powered Cars?” Popular Science Vol. 192, No. 4 (April 1968), pp. 75-77; Douglas Self, “Rotary Steam Engines” (27 October 2009, The Museum of Retro Technology, www.aqpl43.dsl. pipex.com/ MUSEUM/ POWER/ rotaryengines/ rotaryeng.htm, accessed 7 October 2011) and “Rotary Internal-Combustion Engines” (19 October 2009, The Museum of Retro Technology, www.aqpl43.dsl. pipex.com/MUSEUM/POWER/ unusualICeng/ rotaryIC/ rotaryIC.htm, accessed 7 October 2011); Don Sherman, “Mazda Cosmo,” Car and Driver Vol. 21, No. 8 (February 1976), pp. 60-64, 82; Steve Smith, “1972 Mazda RX-2: With or Without Rotary Power, This Car is Ergonomic Perfection,” Motor Trend Vol. 24, No. 11 (November 1972), www.motortrend. com/ classic/ roadtests/ 7211_1972_mazda_rx_2/ viewall.html, accessed 9 October 2011; “Specifications: 1974 Imported Cars,” Car and Driver Vol. 19, No. 5 (November 1973), pp. 93-95; “Super Coupe Comparison Test,” Car and Driver Vol. 16, No. 6 (December 1971), pp. 25–32, 68–70; “Superrob” (12 January 2011, Mazda Owners Club SA, www.mazdaownersclub. co.za/ viewtopic.php? f=2&t=6128, accessed 9 October 2011); “The new Mazda — checking it out on the road,” Changing Times: The Kiplinger Magazine Vol. 26, No. 6 (June 1973), pp. 11-13; “The Series….1.. 2.. 3.. 4.. Rx2… Capella 616” (no date, home.alphalink.com. au/ ~hillsk/ capella1.htm, accessed 9 October 2011); Andrew Tobias, “The Mazda Drives East,” New York Vol. 5, No. 48 (27 November 1972), pp. 66-69; Charles Trieu, “1973 Mazda RX 3 – Rotary Experiment,” Super Street February 2010, www.superstreetonline. com, accessed 10 October 2011; Mark Warner, Street Rotary: How to Build Maximum Horsepower & Reliability into Mazdas (New York: HPBooks, 2009); Larry Webster, “How It Works: The Mazda Rotary Engine (With Video!)” Popular Mechanics September 2011, www.popularmechanics. com/ cars/ news/ fuel-economy/ how-it-works-the-mazda-rotary-engine- with-video, accessed 7 October 2011; J. Patrick Wright, On a Clear Day You Can See General Motors: John Z. DeLorean’s Look Inside the Automotive Giant (Chicago, IL: Avon Books, 1980); Wally Wyss, “Mazda Wankel vs. Comet 302,” Motor Trend Vol. 23, No. 5 (May 1971), pp. 76-78, 87; and an email to the author from Ben Hsu of Japanese Performance Cars, 28 October 2011.

Additional information on Mazda’s rotary competition efforts came from “Bathurst 1971: Hardie-Ferodo 500,” “Bathurst 1972: Hardie-Ferodo 500,” “Bathurst 1973: Hardie-Ferodo 1000,” “Bathurst 1974: Hardie-Ferodo 1000,” “Bathurst 1975: Hardie-Ferodo 1000,” and “Bathurst 1976: Hardie-Ferodo 1000” (no date, Unique Cars and Parts, www.uniquecarsandparts. com.au, accessed 7 November 2011); Patrick Bedard, “Rotary Racer and Piston Politics,” Car and Driver Vol. 19, No. 10 (April 1974), pp. 58-74; Jim Donnelly, “Baby, It’s You: IMSA RS, the Ellis Island of Japanese-branded sedan racing,” Hemmings Sports & Exotic Car #56 (April 2010); “Former Hunterdon resident Walt Bohren, Mazda car racer for many years, drowns in British Virgin Islands,” Hunterdon County Democrat 10 February 2011, www.nj. com, accessed 13 October 2011; Michael J. Fuller, “An Interview with Jim Downing,” conducted 20 January 1996 (2000, www.mulsannescorner. com/ downing.htm, accessed 12 October 2011); Alexis Gosseau, “IMSA RS Challenge : everybody could go racing” (25 October 2009, IMSAblog, alex62.typepad. com/ imsablog/ 2009/ 10/ imsa-rs-challenge-everybody-could-go- racing.html, accessed 10 October 2011); Berny Herrera, “Rotary Power Shines at the 2006 SCCA Solo National Championships” (4 October 2006, RotaryNews.com, rotarynews. com/node/view/844, accessed 12 October 2011); Jeff Koch, “Le Mans-winning Mazda 787B to appear at the Japanese Classic Car Show” (24 August 2011, Hemmings Blog, blog.hemmings. com/index.php/2011/ 08/24/ le-mans-winning-mazda-787b-to-appear-at-the- japanese-classic-car-show/, accessed 13 October 2011); Aaron Robinson, “Checkered Past,” Car and Driver April 2007, www.caranddriver. com, accessed 15 October 2011; Chris Rosamond, “Epic Mazda 787B Rides Again: 700hp rotary racer to return for Le Mans demo” (23 May 2011, PistonHeads, www.pistonheads.com/news/default.asp?storyId=23665, accessed 13 October 2011); “Second Crop of Classes Halfway to a Solo National Championship” (27 September 2007, SCCA, newsarticle.aspx? hub=3&news=3163, accessed 12 October 2011); and Brock Yates, “The New Little Engine That Couldn’t,” Sports Illustrated 16 April 1973, pp. 79-81, sportsillustrated.cnn. com, accessed 19 October 2011.

Additional information on the environmental legislation of the 1970s and the 1973 OPEC embargo came from Chris Bishop, ed., The Encyclopedia of 20th Century Air Warfare (London: Amber Books/Barnes & Noble, 2004); California Environmental Protection Agency Air Resources Board, “Key Events in the History of Air Quality in California” (13 January 2011, ARB, www.arb.ca. gov/ html/brochure/ history.htm, accessed 18 October 2011); Anthony Curtis, “Is cleanliness three-cornered?” New Scientist and Science Journal Vol. 49, No. 740 (25 February 1971), pp. 415-417; Environmental Protection Agency, “Milestones” (9 July 2007, EPA, www.epa. gov/ oms/ invntory/ overview/solutions/ milestones.htm, accessed 10 October 2011); David Halberstam, The Reckoning (New York: William Morrow and Company, 1986); Michio Hashimoto, “History of Air Pollution Control in Japan,” How to Conquer Air Pollution: A Japanese Experience (Studies in Environmental Science 38), ed. Hajime Nishimura (Amsterdam: Elsevier Science Publishers B.V., 1989), pp. 1–90; David C. Isby, Jane’s Air War I: Fighter Combat in the Jet Age (New York: Collins Reference, 1997); National Traffic Safety and Environmental Laboratory, “Overview and Future Prospect of Emissions Regulations in Japan” (4 February 2003, NTSEL, www.ntsel. go.jp/e/ symposium/040203session4.pdf, accessed 10 October 2011); Donald Neff, Warriors Against Israel: How Israel Won the Battle to Become America’s Ally 1973 (Ft. Collins, CO: Linden Press, 1981); Hajime Nishimura and Masayoshi Sadakata, “Emission Control Technology,” How to Conquer Air Pollution: A Japanese Experience, pp. 115–115; the official website of the Organization of the Petroleum Exporting Countries, www.opec. org, accessed 14 November 2011; and the Wikipedia® entries on the 1973 oil crisis (en.wikipedia.org/wiki/1973_oil_crisis, accessed 13 October 2011) and the Yom Kippur War (en.wikipedia.org/wiki/Yom_Kippur_War, accessed 14 November 2011).

Additional information came from the Auto Editors of Consumer Guide, “1963-1966 NSU Wankel Spider” (24 July 2007, HowStuffWorks.com, www.howstuffworks. com/ 1963-1966-nsu-wankel-spider.htm, accessed 7 October 2011); International Money Fund, “Cooperation and reconstruction (1944–1971)” and “The end of the Bretton Woods System (1972–1981),” About the IMF: History, N.d., www.imf.org/external/about/history.htm, last accessed 2 April 2014; Jim Kaler, “Capella” (13 December 1998, University of Illinois Department of Astronomy, stars.astro. illinois.edu/ sow/ capella.html, accessed 13 October 2011); “Kohei Matsuda, Former President of Mazda,” New York Times 4 August 2002, www.nytimes. com, accessed 14 November 2011; Jona Lendering, “Ahuramazda and Zoroastrianism” (no date, www.livius. org/ ag-ai/ ahuramazda/ ahuramazda.html, accessed 13 October 2011); “NSU Wankel Spider” (2008, NSU Prinz, www.nsuprinz. com/ Models /NSU_Spider.asp, accessed 7 October 2011); Masaaki Sato, The Honda Myth: The Genius and His Wake (New York: Vertical, Inc., 2006), and The Toyota Leaders: An Executive Guide, trans. Justin Bonsey (New York: Vertical, Inc., 2008); “Showroom Stock Sedans: The Nine Cars on the Track,” Car and Driver Vol. 17, No. 11 (May 1972), pp. 38-45; Eiji Toyoda, Toyota: Fifty Years in Motion (Tokyo: Kodansha International, 1987); the Wikipedia entries on the Bretton Woods system (en.wikipedia.org/wiki/Bretton_Woods_system, accessed 1 November 2011), Jim Downing (en.wikipedia.org/wiki/Jim_Downing, accessed 12 October 2011), Jujiro Matsuda (en.wikipedia.org/wiki/Jujiro_Matsuda, accessed 13 October 2011), the Mazda Capella (en.wikipedia.org/wiki/Mazda_Capella, accessed 28 October 2011), Mazda Cosmo (en.wikipedia.org/wiki/Mazda_Cosmo, accessed 16 October 2011), the Mazda Familia (en.wikipedia.org/wiki/Mazda_Familia, accessed 26 October 2011), Mazda Grand Familia (en.wikipedia.org/wiki/Mazda_Grand_Familia, accessed 3 November 2011), the Mazda Luce, en.wikipedia.org/wiki/Mazda_Luce, accessed 16 October 2011, the Mazda R100 (en.wikipedia.org/wiki/Mazda_R100, accessed 7 October 2011), the Mazda RX-2 (en.wikipedia.org/wiki/Mazda_RX-2, accessed 9 October 2011), the Mazda RX-3 (en.wikipedia.org/wiki/Mazda_RX-3, accessed 10 October 2011), NSU Motorenwerke (en.wikipedia.org/wiki/NSU_Motorenwerke, accessed 7 October 2011), the NS Savvanah (en.wikipedia.org/wiki/NS_Savannah, accessed 13 October 2011); The Return of Ultraman (en.wikipedia.org/wiki/The_Return_of_Ultraman, accessed 9 October 2011), and the SS Savannah (en.wikipedia.org/wiki/SS_Savannah, accessed 13 October 2011).

Some historical exchange rate data for the dollar and yen came from Lawrence H. Officer, “Exchange Rates Between the United States Dollar and Forty-one Currencies” (2011, MeasuringWorth, https://www.measuringworth.org/exchangeglobal/, used with permission). Exchange rate values cited in the text represent the approximate equivalency of Japanese and U.S. currency at the time, not the contemporary U.S. suggested retail prices, which are cited separately. Please note that all exchange rate equivalencies cited in the text are approximate; this is an automotive history, not a treatise on currency trading or the value of money, and nothing in this article should be taken as financial advice of any kind!



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  1. I’ve always loved Mazda’s rotary cars. Fantastic article, and I can’t wait for part 2…

  2. Great story looking forward to part 2. A friend in Tasmania had several of those bertone Luces nice cars the later models had the 1800 Capella engine.

  3. Thanks for the Mazda rotary article. I’m looking forward to reading Part 2. Despite growing up around Mazda rotary-powered cars, I learned quite a bit!

  4. It’s a real shame that no one can seem to lick the engine’s fuel and oil consumption problems. I have heard some discussion of Mazda using rotaries in hybrids, which makes some sense to me. Rotaries are so small and, on paper at least, elegantly designed.

    Man, that Luce coupe is a looker.

    1. I don’t know about hybrids, but Mazda has done quite a bit of development on a hydrogen-fueled rotary, which has been offered on a limited basis for fleet sales in some markets.

      If the next-generation 16X engine materializes, Mazda is hoping to reduce fuel consumption substantially, in part by adopting direct injection. Still, since piston engines keep improving in that regard, as well, I don’t know that the rotary will ever match the reciprocating engine in specific fuel consumption. Some things can be mitigated (like wall quench), but other factors, like the combustion chamber surface area to volume ratio, are sort of the nature of the beast.

      The Luce R130 is indeed a very nice-looking car. I’d never seen one before I started researching this story.

  5. Very interesting article, well, as usual, Aaron!
    The topic was somewhat forgotten in France after Citroën heavily invested in the technology, eventually failed to make it work and had to drop the project in the early 70’s. They had been so serious about it that the models developed in the late 60’s, the GS and the XM, were designed for a rotary. They had to hastily develop a reciprocating engine for the GS and make it fit in the engine bay that was not large enough.
    The XM eventually was painfully fitted with a Peugeot engine.
    Anyway Citroën was never able to design a good engine. This huge investment and its failure played an important role in the demise of the company.


    1. “They had been so serious about it that the models developed in the late 60’s, the GS and the XM, were designed for a rotary.”
      You mean the SM, don’t you?

      1. I believe Nicolas was probably referring to the CX, which replaced the Citroën DS in 1974. I’ve never heard anything about the SM being intended for rotary power — of course the production cars had the Maserati V6 — but I think the CX was. The XM was the CX’s eventual successor, introduced in the late eighties.

  6. Right Aaron, my pen slipped, it was the CX.
    The XM was its successor.
    The SM, stangely enough, was fitted with the (in)famous Maserati V6 even though Citroën had such a faith in the future of the rotary as the ultimate replacement of the reciprocating.


    1. Timing may have had something to do with it. Citroën didn’t build the first M35 single-rotor cars until the fall of 1969, and as I understand it, they were essentially evaluation models, not yet intended for large-scale production. The BiRotor wasn’t introduced until 1974, about four years after the SM debuted. Even if Citroën were keen to give the SM rotary power, it probably wouldn’t have been ready until a few years after launch, even in a best-case scenario.

      If things had worked out differently, I imagine Citroën might have added a rotary engine to the SM later, perhaps in a second-generation version for the mid-seventies. Of course, even if the Comotor engines had been more successful, the SM was not, and might have been dropped without ever getting a rotary engine.

  7. For them the rotary was the future type of engine for all applications, just as well as they were persuaded they had a market for the SM.
    With NSU, Mazda and others working on it it’s understandable.
    Your article is very interesting by showing how Mazda made a success of it, or at least could partly make a living with it, well… that’s a success, isn’t it?
    Strangely enough it didn’t catch on as an aviation engine either.

  8. [quote=Administrator] Citroën didn’t build the first M35 single-rotor cars until the fall of 1969, and as I understand it, they were essentially evaluation models, not yet intended for large-scale production. The BiRotor wasn’t introduced until 1974, about four years after the SM debuted.[/quote]
    Starting in 69 a limited number M35, and in 73 GS Birotor, were sold to selected, faithful (and masochist) clients but the engine proved such a burden to maintain that Citroën offered to buy them back and scraped them. A few people only turned down the offer. The maintenance contracts were canceled for them. The few models still in existence are now very expensive collectors’ items, the day dream of all the GS enthusiasts.
    So there was actually a future for the rotary! ;-) As usual the car that nobody wanted became the car that nobody can afford.


    1. The source I was looking at (John Hege’s The Wankel Rotary Engine: A History) suggests that Citroën had basically intended to buy back the early evaluation engines from the outset, which would make a lot of sense.

      I don’t know about France, but in the U.S., automakers are legally obligated to provide parts support for production models for a specific period of time, typically 15 years — obviously not an appealing prospect for cars or engines that don’t end up in mass production! For that and other reasons, some automakers have tended to offer such evaluation vehicles only as a closed-end lease or other type of loan-out, with no option to actually purchase and keep the vehicle at the end; I assume that not actually selling it avoids triggering certain legal requirements.

  9. The Europeans have basically the same obligations as the Americans. As far as I understood, the deal was under specific conditions and since Citroën offered to buy them back it could cancel any support for those who rejecter the offer. It’s stupid it didn’t keep one example for history.

    Mazda is the only one who succeeded with a rotary over the years while all the others flopped.
    Well done!

  10. This is an interesting article as usual, I’m waiting for the second part. While you’re at it, how about an article covering GM’s attempt to build a rotary engine?

    1. I thought about it, but in researching this article, I’m finding that detailed information about its development seems to be surprisingly scarce. While the development of the NSU, Mazda, and Curtiss-Wright engines is pretty well-documented, GM played it very close to the vest. To really do it justice would probably require talking to some of the engineers who worked on it, assuming that the people involved are still living, and willing (and able) to talk about the program.

  11. No need to mourn it’s passing. A technological dead end. I don’t miss the
    ffffttttt exhaust “note” of them at all.
    Used to be a few about Brisbane, Delighted to see and hear that rust and enlightenment of the owners has made them almost extinct.

    Good riddence. So it could rev to 5 digits.

  12. Wow, FANTASTIC article! Thanks for the great piece on Mazda, the detail and depths you go to are above and beyond. One of the best history-of-automaker stories that I’ve read. Thanks again!

  13. Another great article Aaron. Really appreciating your narrative drive and level of scholarship. I’m starting to believe the R100/1200 body was designed by Bertone as well, but can’t verify. Do you know of any text that addresses the connections between the Italian design houses and the Japanese manufacturers in depth?

    1. I so far haven’t found anything to suggest one way or another whether the first-generation Familia was done by Bertone, although it’s certainly plausible given that Bertone did the first Luce and the Luce Rotary Coupé in that period. Even if Stilo Bertone didn’t do the Familia or the first Capella, those designs have a definite Italian flavor, much more so than subsequent products of Toyo Kogyo’s in-house design studio, which feel more typically mid-seventies Japanese.

  14. I really like that little sidebar referring how to calculate the Wankel’s full displacement. I know Japan has different regulations than the U.S. and that Mazda had no choice to only count one chamber for each rotor (Geometric Displacement) due to extra taxes being placed on “bigger” cars. Either way, I really hope Mazda brings their Wankel rotaries back to the streets, because that awesome RX-Vision concept needs to be on the roads

  15. In retrospect could the prospects of the Rotary have been slightly improved to a certain extent had Mazda and not Citroen established the Comobil later Comotor joint-ventures with NSU, where the development of the Rotary follows a more developed Mazda like trajectory instead of the engine being prematurely released as was the case with NSU and Citroen?

    Would that have been enough had it been feasible to largely butterfly away the poor reputation and resolve the issues of the early Rotary engines or would more changes have been required? Taking into consideration of course the current disadvantages of the Rotary would still remain.

    1. This is one of those “could / would /should” questions. The “could” part is straightforward, at least technologically speaking; Mazda obviously managed to keep the rotary at least reasonably viable for many years, so there’s no technical reason the fruits of their efforts couldn’t have been shared across a broader consortium.

      The “would” and “should” parts are more complicated. NSU-Wankel patent licensing agreements generally included technology-sharing provisions because NSU did not have deep pockets and figured that pooling research data would be the best way to advance the art. (Part of the reason GM’s patent license was so expensive is that GM didn’t want to participate.) Toyo Kogyo participated in that and probably contributed quite a bit to it. However, the way that knowledge was applied ended up being dictated by other factors, including a maze of different licensing agreements (like the one with Curtiss-Wright that affected distribution in North America), the concessions NSU minority stockholders wrested during the Audi merger, and the fact that the Comobil/Comotor project contributed to Citroën’s financial over-extension and eventual bankruptcy.

      Would NSU stockholders have agreed to set up such a consortium or joint venture with Toyo Kogyo? Possibly, and in that area, the progress Mazda had made with the technology might have been attractive. Would Volkswagen have been amenable to it after the NSU-Audi merger? Harder to say; I don’t imagine that Volkswagen or Audi were terribly keen on Comotor given the NSU shareholder concessions, and Toyo Kogyo being involved in that venture rather than Citroën (or succeeding Citroën) would not have changed that part of the equation. The minority shareholder deal ended up signing away most of the opportunity to profit from the rotary, and Volkswagen still wouldn’t have been in a position to use the rotary in its own products. (I don’t think Toyo Kogyo would have been in a position (financial or political) to acquire NSU instead of Volkswagen.) The main point of change in that scenario is that Toyo Kogyo by then had sunk enough money into development that they were more reluctant to simply shelve it.

      Should they have? It depends on a lot of things. If Toyo Kogyo had stepped in AFTER Citroën had been forced to bow out, the venture would have had to rebrand and might still have had a shaky image. There were customers who would have been interesting (AMC, to name one), but Mazda rotary combustion engines of the early seventies were still not without flaw, and the issues might have caused their licensees to jump ship early. (Toyo Kogyo commitment to the rotary had a lot to do with pride and the sunk-cost fallacy, to be honest.) Also, the OPEC embargo would still have really pressed the rotary’s limitations in terms of fuel consumption, which would have still hurt the project’s commercial prospects.

      So, an interesting idea, but I tend to see it coming to a similar end.

      1. Do not envision a joint-venture between NSU and Mazda in place of NSU and Citroen significantly changing things once Volkswagen acquires NSU and merges it with DKW/Auto Union to form Audi, what with the fuel crisis hurting the rotary engine’s projects in Europe. That said the NSU Ro80’s issues would have been largely butterflied away for one thing, though not sure if it would be enough for Volkswagen to actually consider a rotary model for say the 914 (as was experimented in real-life) if not a small mid-engined sportscar or some other vehicle (.

        For Citroen there is one less contributor to its financial over-extension and eventual bankruptcy, leaving only one or few more elements (e.g. Project F, possibly acquiring Maserati for V6, SM instead of DS Sport, etc) to be remedied on its end without being involved in the Comobil/Comotor project. What Citroen goes from hereon is another matter, in the absence of the French government forcing Peugeot to acquire Citroen perhaps Citroen ends up increasingly entangled with Fiat or collaborates with one and more carmakers on a few joint-ventures outside of Fiat (e.g. Alfa Romeo? Subaru? both? etc).

        Essentially the rotary engine in this scenario would be better regarded compared to real-life thanks to Mazda’s early tie up with NSU and a thorough development programme (instead of being prematurely released), yet ultimately undermined by the fuel crisis and only really considered worthwhile for sportscars.

        1. The issue pertaining to the NSU-Auto Union merger (which is explained in more detail in the Ro80 article) is that Volkswagen ended up signing away the lion’s share of Wankel-related profits and agreeing that if it used the rotary in its own products, it would have to pay license fees like any outside customer. In the short term, that was a big win for NSU minority shareholders, but it probably contributed a lot to the eventual stagnation of rotary development outside Toyo Kogyo/Mazda. On the other hand, NSU’s survival WITHOUT a merger would have been very tenuous because they had also overextended their resources with the Ro80 and what became the Volkswagen K70. Whether Toyo Kogyo would or could have afforded a merger with NSU that would have obviated the need for the Volkswagen deal I don’t know; it would have been a politically complex situation, to say the least.

          NSU was undoubtedly aware of everything Toyo Kogyo had been doing regarding rotary development, which to my understanding was a condition of the original license agreement. (I assume NSU would still have had to formally license technology subject to Toyo Kogyo patents, although I don’t think that would have been an insurmountable obstacle.) However, the problem they both faced is that each was exploring different solutions to the challenges involved (like the apex seal issue), and it wasn’t yet apparent what would work best. Toyo Kogyo didn’t attempt anything quite as daring as the NSU floating seal design (which was a brilliant idea undermined by inadequate development testing), but the differences between the earliest 12A twin-dizzy engines and the better-developed 13B found in the first-generation RX-7 are pretty substantial. It’s not that Toyo Kogyo was smarter or luckier than NSU in this regard; it’s that they kept working on it and refining their approach to factors like sealing and porting.

          However, the upshot I assume you’re getting at is that an alliance between NSU and Toyo Kogyo might have resulted in a more lasting commitment to developing the rotary engine as a commercial prospect, with a Comobil/Comotor-style entity offering engines to other companies that were interested in the technology, but either couldn’t afford or didn’t want to spend the money on developing their own. The actual reason that didn’t happen was probably mostly that Volkswagen had very limited financial incentive to bother and Citroën, as mentioned, ran out of money. If Volkswagen were not in the picture (or the settlement with the minority stockholders had turned out differently), NSU survived on its own, and Toyo Kogyo took Citroën’s place as development partner, it might be plausible.

          One other fly in the ointment with that scenario, though, is European hostility toward Japanese automakers. As much as the emergence of Japan as a major player on the automotive scene aroused horrendous racism and nationalistic furor in the U.S., that hasn’t significantly dissuaded Americans from buying Japanese cars, to the point that domestic automakers have more or less abandoned many segments of the market to the Japanese and Koreans. European markets have not been nearly so amenable, and even products Japanese automakers have designed specifically for Continental or British tastes have often been commercial duds. Applying that chauvinism to the early seventies, it’s also not hard to envision a scenario where Toyo Kogyo partnership in a Comotor-type JV ends up leading European punters and pundits deciding that rotary engines are too Japanese, which combined with the pressures of the OPEC embargo might also have been a death knell.

          1. Volkswagen could have attempted to use the rotary in more niche segments like Mazda did with front-engined sportscars though mid-engined in Volkswagen’s case, otherwise Volkswagen could be a passive beneficiary at best upon buying NSU.

          2. As it says in the Ro80 article, there was a lot of enthusiasm within Audi-NSU for the planned Ro80 successor, including some fairly serious talk of installing its 1.5-liter KKM 871/EA871 engine in the Audi C2. However, the minority shareholder settlement would have made using that or other Wankel engines in Volkswagen models fairly costly, which I think was a big part of why the whole plan ultimately didn’t go anywhere.

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