In 1972, with an annual production of 877,963 cars, Opel had become Germany's largest automobile manufacturer. The oil crisis speeded up the development of new cars.
With the introduction of the new C-Kadett, (GM called it the world car) Opel tried to keep the economic damage of the crisis within limits. The Kadett production was decreased by 30% compared to the Kadett B.

In 1973, the Kadett C, went into production in various countries : in Great Britain as the Vauxhall Chevette, in the United States as the Chevrolet Chevette, the Kadett K180 in Argentina, in Brazil as the Chevrolet Chevette, as the Bellet Isuzu Gemini in Japan and in Australia as the Holden Gemini.
The main technical characteristics of the Kadett C (which was introduced in August 1973), were: a lightweight self-supporting body in various  designs, (a two-door and a four-door sedan, a coupe and a wagon and later in 1975 followed by the City), an independent front suspension with coil  springs, a rigid rear axle with coil springs and the famous four-cylinder overhead valve 1.2-liter (N engine with 52 hp and the 60 hp motor S type).
Because of the 1974 oil crisis, the 993cc engine-which had been used in the  Kadett B- was reintroduced and produced 40hp.

Opel demonstrated the GT/ E at the IAA in Frankfurt in August 1975. This Kadett coupe with its 1.9 injection engine had a performance of 105pk. This particular engine was later used in the Manta GT/ E and the SR. In 1977 the Kadett coupe was  slightly modified with the 20E which had been applied to the Rekord.

Besides the GT/ E model, in that year, Opel also introduced a rally version with either a 16S or 20E engine.

Simultaneously, the strong 16S 75ps engine was available in the other Kadett models.
The Aero Kadett appeared in 1976. Right up to the B-pillar it was a regular Aero 2 door sedan, in which a removable roof panel, a strong vinyl cover and a short convertible roof  jointly formed the roof. To convert the sedan to a convertible, the Opel parts company handed this assignment over to the Bauer firm in Stuttgart. 

Until 1979, a total of 1.7 million C-kadett were produced in various designs.