The first Mazda to bear the Cosmo name (called the 110S) was one of the first 2-rotor rotary engine powered cars. A prototype was introduced at the 1964 Tokyo Motor Show, and 80 pre-production Cosmos were produced for the Mazda test department (20) and for dealership testing (60) between 1965 and 1966. Full production began in May 1967 and lasted through 1972, though Cosmos were built by hand at a rate of only about one per day. The car was also featured in the show Return of Ultraman.
Cosmos were built in five batches:
In 1968, Mazda went racing with the Cosmo. They selected one of the most grueling tests in Europe to prove the reliability of the rotary engine, the 84-hour Marathon de la Route at the legendary Nürburgring circuit in Germany. Two mostly-stock Cosmos were entered, along with 58 other cars. One major change to the cars' 10A engines was the addition of a novel side- and peripheral-port intake system: A butterfly valve switched from the side to the peripheral port as RPMs increased. The engines were limited to 130PS to improve durability.
The cars ran together in fourth and fifth place for most of the race, but the all-Japanese car was retired with axle damage in the 82nd hour. The other car, driven by Belgians, completed the race in fourth overall. This was to be the only racing outing for the Cosmo - the next Mazda race car would be a Familia Rotary (R100).
The Series I/L10A Cosmo was powered by a 0810 two-rotor engine with 982cc of displacement and produced about 110hp (thus the 110 name). It used a Hitachi 4-barrel carburetor and an odd ignition design - two spark plugs per chamber with dual distributors. A 4-speed manual transmission and 14in wheels were standard.
The front independent suspension was A-arm/coil spring design with an anti-roll bar. The rear used a live axle with a de Dion tube, trailing arms, and semi-elliptic leaf springs. Power-unassisted 10in (254mm) disk brakes were found in front with 7.9in (201mm) drum brakes in the rear. Performance in the quarter-mile (400m) was 16.4s, with a 115mph (185km/h) top speed. The price was lower than the Toyota 2000GT at 1.48 million yen (US$4,100).