Audi 100 (1968-1994): from the C1 to the C4

Few models have weighed as heavily in a brand's history. Without the Audi 100, Audi might have remained a secondary division of the Volkswagen group. With it, the Ingolstadt marque established itself over twenty-six years and four generations in the large saloon market, until it became the premium manufacturer we know. And it all starts with an act of disobedience.

The C1 (1968-1976): the birth of a range

The Audi 100 was presented in late 1968 as a four-door saloon. It received a 1.8-litre four-cylinder engine, producing 100 hp in the LS version. A two-door saloon followed in October 1969.

The most desirable version today is the Coupé S, sold from 1970. A two-door, four-seater coupé, it received a 115 hp 1.9-litre engine. Only around 30,700 were built, which makes it a rare and sought-after car.

In total, the first generation exceeded 827,000 cars. For a car that nobody wanted to build, it is a resounding revenge: the Audi 100 established Audi in the upmarket family saloon segment. Demand was such that production, first launched at Ingolstadt, also spread to the Neckarsulm plant, which would later assemble the C3 and C4.

The C3 (1982-1991): aerodynamics as a selling point

The third generation, launched in 1982, struck people with its smooth lines. Flush windows, rounded shapes: the base version achieved a drag coefficient (Cd) of 0.30, a record for a production car at the time. Less air resistance means lower fuel consumption and less noise, and Audi made it a selling point.

Recognition came quickly: the Audi 100 was voted European Car of the Year 1983. It is the only time the 100 won this title (the Audi 80 had won it in 1973).

The C3 brought other decisive advances:

• the quattro four-wheel-drive system, offered on the 100 from the mid-1980s, after its launch on the Quattro coupé;
• a fully galvanised body, a guarantee of longevity against corrosion;
• the brand's first TDI engine: presented at the 1989 Frankfurt Motor Show, the Audi 100 TDI received a 2.5-litre direct-injection turbo five-cylinder Diesel, producing 120 hp.

The C4 (1990-1994): the V6, then the A6 name

The fourth generation appeared in late 1990. It introduced the 2.8-litre V6, which gave the 100 the smoothness expected in this segment. The TDI and quattro versions stayed in the catalogue.

In 1994, Audi adopted a new naming system, with an A followed by a number, already applied to the A4 and A8. The facelifted C4 was then renamed the A6. After twenty-six years and four generations, the Audi 100 name disappears, but the line continues: the current A6 is its direct descendant.

Audi 100 milestones

• Late 1968: presentation of the four-door saloon (C1).
• October 1969: two-door saloon; the Coupé S follows, sold from 1970.
• August 1976: presentation of the C2; the petrol five-cylinder was delivered from March 1977.
• 1978-1979: Diesel five-cylinder, then turbo on the Audi 200 5T.
• 1982: the C3 and its Cd of 0.30; European Car of the Year 1983.
• 1989: the Audi 100 TDI is presented at the Frankfurt Motor Show.
• Late 1990: the C4 and its 2.8-litre V6.
• 1994: the 100 becomes the A6.

The codes C1 to C4 are internal designations that are now used to tell the generations apart. They are valuable when ordering a part: the same commercial name, "100" or "100 CS", covers very different cars depending on the generation.

Driving an Audi 100 today

Each generation has its following. The C1, especially as a Coupé S, appeals to fans of classic lines. The five-cylinder C2 remains a technical curiosity, still little known. The galvanised C3 and the V6 C4 are robust youngtimers, easy to live with every day.

Before buying, a few points to watch that are common to saloons of this age:

• corrosion on the C1 and C2, which don't benefit from the galvanising of later generations;
• engine identification, essential for ordering the right ignition, injection or timing parts;
• service history, especially on quattro transmissions and early TDIs.

All the available parts can be found on the Audi 100 page, with access by engine to target your engine. The brand's other models are on the Audi page. And if your Audi 100 spends the winter in the garage, our tips on how to winterise your classic car properly will help you find it in good shape in the spring.