What is the DSG dual-clutch gearbox and how does it work?

What is the DSG gearbox? This type of automatic gearbox comes from the Volkswagen Group, and today it is hard to find one of its models that does not fit it. The letters of its name stand for Direct Shift Gearbox, and it can be said to have revolutionised transmission systems, since until its arrival, automatic gearboxes were relegated to premium vehicles. From that moment on, many manufacturers began developing their own automatic dual-clutch gearboxes.

When the German group considered equipping its models with a different type of gearbox, its goal was to keep the benefits of both manual and automatic transmissions. The automatic dual-clutch gearbox that Volkswagen wanted to develop had to be fast, simple and smooth. According to the manufacturer, these three characteristics define the DSG gearbox.

The first cars to fit this type of gearbox were the Porsche 956 and the Porsche 962 from Le Mans, and the Audi Quattro S1.

It is important to note that the father of the dual-clutch gearbox is Adolphe Kégresse. This engineer was part of the Citroën team and was the one who began developing this type of automatic gearbox. Years later, the German group revived Kégresse’s idea.

The first Volkswagen with a dual-clutch gearbox

The legendary Volkswagen Golf R32 was the first sporty compact to fit the brand’s DSG dual-clutch gearbox. Its market debut came in 2003, and it has become a standard fitment on the best-selling model of the German brand, the Volkswagen Golf.

It should be noted that the DSG dual-clutch gearbox belongs to the VAG Group and all the brands that make it up: Volkswagen, Audi, SEAT, SKODA, Porsche, Bentley, Bugatti, Lamborghini and Porsche, all offer models with this type of transmission. Although it is the same type of gearbox, Audi calls it S Tronic and Porsche calls it PDK.

The dual-clutch transmission is not only found in models from the Volkswagen Group. Ford calls it PowerShift, Renault calls it EDC, Alfa Romeo calls it TCT, Kia calls it DCT, and Mercedes-Benz names it DCT.

How does a dual-clutch gearbox work?

The theory behind the operation of the dual-clutch gearbox is simple: as its name suggests, it has two clutches. Each clutch controls one primary shaft, which in turn drives the secondary shafts where the gears sit. One of them drives the even gears and the other drives the odd gears and reverse.

The purpose of having two clutches is speed. It is important to note that this type of transmission, in its first version, could change gear in just 40 milliseconds. Over time, the DSG gearbox has evolved and this time has been reduced even further. So much so that this type of transmission is much faster than a robotised manual gearbox and than a torque converter automatic gearbox.

In addition to speed, its advantages include reduced fuel consumption compared with other types of gearbox, and more efficient power delivery. It is also important to note that this type of gearbox has drawbacks. It requires particular attention to maintenance; it is recommended to change the gearbox oil every 60,000 kilometres. Although smoothness is one of its characteristics, at low speeds it can feel somewhat abrupt.

How has the DSG gearbox evolved?

Over the years, and since its arrival on the market in 2003, the automatic dual-clutch gearboxes of the Volkswagen Group have been fitted to a range of different models. They are now capable of handling more torque and more power. In addition to reinforcing the system, the group has equipped its models with new software that reduces consumption and improves compatibility with the rest of the vehicle.