AUDI is marking 50 years of its legendary five-cylinder engine in 2026 and to mark the occasion it has given a resume of the cars in which it has appeared and a history of its development.

It was first introduced in 1976 in the second-generation Audi 100.

This was followed by upgrades and new developments with turbocharging, exhaust gas purification, and four-valve technology, rally engines, and five-cylinder diesel engines.

Currently, the 2.5 TFSI in the Audi RS 3 continues the great tradition of five-cylinder engines.

The engines have cult status and are deeply rooted in the Audi DNA. They have played a decisive role in shaping "Vorsprung durch Technik" - on the one hand with numerous successes in motorsport, and on the other, by virtue of their outstanding performance in series production.

To this day, the 2.5 TFSI provides a highly evocative driving experience, not least because of its characteristic sound.

The first five-cylinder engine powered the Audi 100 in 1976. Known internally as Type 43, the model was intended to be positioned higher in the market than its predecessor.

The four-cylinder engines of the time were not sufficient for the developers' plans. Audi engineers therefore discussed using inline five-cylinder and six-cylinder engines in the early 1970s.

The latter were ruled out due to space constraints and the unfavourable weight distribution.

As a result, those responsible opted for the inline five-cylinder engine, which was based on the EA 827 engine concept, still in its infancy at the time.

This inline four-cylinder engine was used throughout the Volkswagen Group in the 1970s, including in the Audi 80 and Audi 100.

The five-cylinder engine derived from it, with a displacement of 2,144 cc, delivered 100 136ps.

Deliveries of the Audi 100 5E began in March 1977.

Audi launched its first diesel version back in 1978 - a naturally aspirated diesel with a displacement of two-litres and 70ps.

One year later, the first five-cylinder gasoline engine with turbocharging made its debut with 170ps and 265 Nm of torque, it powered the new top model, the Audi 200 5T. The five-cylinder gasoline engine in the original 1980Audi quattroreached even greater heights.

Featuring turbocharging, intercooling, and permanent all-wheel drive, it formed a powerful technology package for both racing and the road.

At the start of sales, it had a power output of 200ps.

After Audi secured the World Rally Championship title in 1982 with this car, Finnish driver Hannu Mikkola won the drivers' title in the World Rally Championship a year later.

Also in 1983, Audi introduced theSport quattro, which was 24 centimetres shorter and had a wider track. It was powered by a newly developed four-valve, five-cylinder light-alloy engine with 306ps.

This made the Sport quattro the most powerful car ever offered by a German company for use on public roads up to that time.

Audi unveiled another milestone in automotive history at the 1989 International Motor Show in Frankfurt am Main - the Audi 100 TDI.

In 1994, theAvant RS2with 315ps was brought onto the market. As an Avant with sports car power, it became the founding model of a new automotive class.

With the introduction of the Audi A4 in 1994, five-cylinder engines made their exit from the medium segment. The new V6 engines gradually replaced them in the mid-1990s.

The last five-cylinder engines - the 2.5 TDI in the Audi A6 and the 20V turbo with a displacement of 2.2 litres in the Audi S6 - were phased out in 1997.

In 2009 - 30 years after the debut of the first five-cylinder turbocharged gasoline engine - the big comeback arrived in the: from 2.5 litres of displacement, the quattro generated 340ps from the transversely mounted engine featuring turbocharging and gasoline direct injection.

It also delivered outstanding performance in the RS 3 Sportback.

The TT RS plus, which Audi introduced in 2012, even achieved 360ps and in 2013, theRS Q3 became the first compact SUV to open up a new market segment.

As in the TT RS and RS 3, it was the 2.5-litre five-cylinder engine that served as the power unit.

A new version of the engine followed in 2016. Thanks to lightweight construction measures, reduced internal friction, and increased power delivery, the engineers achieved a good 17 per cent more power with the same 2,480cc displacement with 400ps and 480 Nm of maximum torque.

Since 2021, the Audi RS 3 has been equipped with a modified version of the 2.5 TFSI, which is more powerful than ever before. It enables the compact sports car to sprint from 0 to 62mph in 3.8 seconds.

The five-cylinder engine is built at the Gyor plant in Hungary, in the so-called Bock assembly, which spans more than 1,000 square metres.

The engine is put together by hand, without the use of robots. The 2.5 TFSI is assembled by qualified specialists at 21 stations before it leaves the factory.

Key components such as the connecting rods and cylinder crankcase, including the plasma coating of the cylinder liners, are manufactured separately in a specialized production area, also at the Gyor plant.

The engine is then transported by train from the GyÅr plant to Ingolstadt where the Audi RS 3 rolls off the production line and the so-called "marriage" takes place - when the 2.5 TFSI is finally installed in the top-of-the-line A3 model.