Promising drivers the smoothness of an automatic transmission with none of the fuel economy compromises, the DSG will first hit the road in the new Audi TT 3.2 V6, but will follow in the A3 range in September for the 2.0 TDI and November for the 3.2 V6.

The gearbox has a double clutch and manual gearchanges take 0.02 seconds, but it can also operate in a fully automatic mode with no fuel consumption penalty. But driving enthusiasts will also note that gearchanges never interrupt the power delivery as with some sequential manual transmissions currently available.

The Audi TT 3.2 V6 DSG is priced at £29,155 on-the-road, while diesel versions of the Audi A3 will go on sale for less than £21,000.

Audi claims the maximum torque that can be handled by DSG is 258lb-ft, so it seems that the current 3.2 V6 engine and the new 2.0 TDI are near the limit of its capabilities, and the traditional automatic transmissions in the more powerful A6, Allroad and A8 models will continue.

And Audi's Multitronic continuously variable transmission will also continue, but DSG offers benefits over Multitronic, traditional autos and conventional manuals.

It is at least as economical as a standard manual, at least as smooth as the best automatic and, unlike CVTs, there isn't the momentary delay before power delivery when setting off.

In fact the TT DSG has a party trick bound to appeal to the boy racers in the company car park. It has an F1-style launch control facility. From rest, switch off the electronic stability programme (ESP), select the 'S' for sport with the gear lever, apply the footbrake with the left foot, and floor the accelerator to the kickdown button behind the accelerator.

Releasing the brake and, with the slightest of squeals from the tyres, the TT takes off with the optimum getaway speed. It means that its 0-62mph time of 6.4 seconds is virtually guaranteed every time you decide to use the launch control.

Sport mode is actually rather frantic compared with normal automatics in sport mode, as the latter can be easily encouraged to change up before the red line when the system realises maximum acceleration is not required. DSG refuses to change up in sport mode until the red line is reached. The other characteristic is that upchanges and downchanges are instant when you select the next gear.

But, for example, when you need to change down two or three gears for an instant blast of power for overtaking, it goes through each gear individually to smooth out the downchange, whereas an Alfa Romeo Selespeed or BMW SMG would get straight to the desired gear and provide a delicious blip of the throttle before continuing. A small point, but noticeable nonetheless.

However, the advantages of DSG outweigh this minor disappointment and despite its torque limitations, it renders obsolete virtually every other sequential manual produced to date.