Mazda R360 Coupe

Tōyō Kōgyō of Hiroshima had begun as a cork maker. It built motorcycles, and from 1931 three-wheeled trucks, the first of them the Mazda-Go.source 4source 5 In 1959 it launched the Mazda K360, a light three-wheeled truck with an air-cooled V-twin, and a related engine went into its first passenger car the next year.source 2 Mazda’s own history says the R360 came off the line of a new plant in 1960, which it describes as computer-controlled.source 6

The car was built to Japan’s kei rules for light vehicles, which then held a passenger car to 360 cc. The project was led by Yamamoto Kenichi, who went on to head Mazda’s rotary-engine programme. The body was shaped by the industrial designer Kosugi Jirō (1915–⁠1981), who had styled Mazda’s three-wheelers, working with Tōyō Kōgyō’s own designers.source 2 The pointed nose and the headlamps set into recesses carried motifs over from those trucks; Kosugi called a natural recess of this kind a “happy shape”.source 2

It was planned as a 2 + 2 on purpose. Most kei cars carried one or two people, so the designers put lightness ahead of a full four-seat cabin. The law counted four seats, but the rear pair were very tight, like the back bench of a kei van, and in practice they were for children.source 2 It was the first Japanese car after the war to be called a coupé.source 2

Magnesium, acrylic and rubber

Everything was made to weigh little. The engine, mounted lengthwise in the tail, was an air-cooled 90° V-twin of 356 cc with overhead valves and a dry sump. Its cylinder head and crankcase were aluminium alloy, its rocker cover and oil pan magnesium alloy.source 1source 2 Carscoops adds an aluminium bonnet and a magnesium gearbox casing.source 7 It gave 16 PS (12 kW) at 5,300 rpm and ran past 5,000 rpm, high for an engine of its day, and for a while afterwards Mazda advertised its aluminium engines as “white engines”.source 1source 2 The side and rear windows were acrylic rather than glass, and the whole car weighed 380 kg (838 lb).source 1source 2source 7 With the manual gearbox it would reach 90 km/h (56 mph) by the figures of the JSAE and the Lane museum, though English Wikipedia, citing an Italian article, gives 84 km/h; the claimed consumption was 32 km to the litre.source 1source 4source 8

Each wheel ran on a trailing arm sprung by rubber in torsion, of the Neidhart type, with a rubber anti-roll bar.source 1source 2 Japanese Wikipedia notes that the ride was soft. Trailing arms at the back, rather than the swing axles usual on rear-engined cars, limited the change of camber at the wheels and the jacking of the tail, and the rubber worked through a longer, gentler stroke than the rubber cones of the BMC Mini.source 2

Two pedals

Beside the four-speed manual there was a two-speed automatic with a torque converter. The JSAE names the R360 as the first kei passenger car with a four-stroke engine and the first with a torque-converter automatic.source 1source 2 The converter came from Okamura Seisakusho, which had supplied it before for the Mikasa of 1957 and the Mikasa Touring of 1958.source 2 It went into the Cony Guppy pickup the next year too.source 9 With no clutch to work, the automatic suited drivers whose legs were disabled, and it was for them that it was built to order until 1969, three years after the manual car ended.source 2

¥300,000

The R360 went on sale in 1960 at ¥300,000, which made it the cheapest four-wheeled passenger car in Japan; the Lane Motor Museum dates the debut to 20 May and gives the price as about US$830.source 1source 2source 4 The Lane says 4,500 orders came in before the car was unveiled, and Carscoops says 4,500 were sold on the first day: probably the same figure, told two ways.source 4source 7 None was built for export, the Lane says, yet former Mazda employees remember about 700 with left-hand drive, said to have been for American servicemen in Okinawa and elsewhere in Japan.source 4 In calendar 1960 Tōyō Kōgyō built 23,417, 64.8% of Japan’s kei passenger-car production that year, and Carscoops puts the R360 at more than 15% of the whole Japanese car market.source 2source 10source 7

Outgrown

The R360 was really a two-seater, and that told against it once the four-seat Subaru 360 came down in price and Mazda launched its own four-seater, the Mazda Carol, in 1962.source 2source 10 The manual car was built until 1966 and the automatic, to order, until 1969; the Weiner museum’s dates, 1960–⁠70, are not borne out by the other sources.source 2source 3source 4source 5 In 2020 Mazda trimmed its centenary special editions in colours that paid homage to the R360.source 2

No count of surviving R360s has been found. Mazda keeps one on static display, as the JSAE’s landmark record notes, and the Toyota Automobile Museum at Nagakute has a KRBB in its main building, together with a Bandai tin toy of the car from the 1960s.source 1source 3 In Nashville, the Lane Motor Museum’s R360 is a 1964 car, fitted with a smaller replacement rear window in place of the original wraparound one.source 4 The Bruce Weiner Microcar Museum had a 1962 De Luxe; what it fetched when the museum’s cars were sold in 2013 has not been found.source 5 More of these places, and others, are on our page of museums and meets.