The five-cylinder success story

​The five-cylinder engine has played an important role in Audi history, beating at the heart of many performance models. Audi created the first production petrol straight-five in the 1970s, used in the Audi 100, which later worked as the base for an Audi rally racing legend.

The five-cylinder engine can still be seen in the current Audi line-up, sharing the genes of the Audi quattro legends from the 1980s in their DNA.

So what is a five-cylinder engine and what makes it special? It’s an internal combustion engine with five cylinders aligned in one row, sharing an engine block and crankcase. The five-cylinder offers increased engine capacity than the smaller inline-four and fits into a smaller space than a straight-six - it requires less room in the engine bay and is suitable for transverse mounting.

The five cylinders fire one after another, rather than with gaps between bursts, meaning that the engine has a smoother power delivery than other engines, with more frequent power strokes and even cylinder fires. But what makes the five-cylinder engine completely unlike the rest is its trademark deep rumble that turns heads as it hums by.

Over the years, Audi has produced a number of five-cylinder engines, starting with the 2.1-litre R5 for the Audi 100 in 1976. In 1981, the Audi 100 also became available with a 1.9-litre variant, the smallest production straight-five. The Audi A6 was powered with a five-cylinder engine from 1978 to 1997, as well as the Audi RS 2 Avant from the mid-90s, so the five-cylinder has remained prominent in Audi’s offering for almost four decades.

The power of the five-cylinder has been utilised in racing for its balance of performing qualities, making it well-suited for rallying in particular. The IMSA GT Championship saw the Audi 90 quattro IMSA GTO perform with its 2.1-litre 20V five-cylinder engine producing 720hp and the famous Group B played host to the 650hp Audi S1 Sport quattro E2. A prototype of this same S1 Sport quattro was tested in 1987 by the factory team and was able to produce 1,000hp, highlighting the capabilities of the five-cylinder engine.

Built to evoke the true spirit of this 1984 Sport quattro that dominated Group B, the Audi quattro concept was unveiled in 2010, combining the latest generation quattro system and inline five-cylinder engine, bringing the technology into the 21st century.