Audi was to unveil the TT at the New York Motor Show next week but stunned the motoring media by showcasing the car in Berlin on Thursday.
According to Audi the new TT coupe is "more dynamic" than its predecessor - in terms of its design, its drivetrain, and its running gear.
Audi says its design team enhanced the bold styling of the previous model, whose theme was a showcase of circles and domes.
The new TT appears more stretched and aggressive looking. It is 137 mm longer than its predecessor at 4 178 mm, and 78 mm wider at 1 842 mm.
Its body is constructed in the ASF Space Frame design developed by Audi and consists of aluminium and steel.
The new Audi TT is initially available as a 2 + 2-seater coupé; the separate roadster model is scheduled for later launch.
Two powerful petrol engines are available to power the car. The entry-level model comes with a 2-litre turbocharged four-cylinder TFSI unit which develops 147 kW.
With a six-speed manual gearbox, it accelerates the TT to 100 km/h in just 6.4 seconds, reaching a top speed of 240 km/h.
At the top of the range sits the naturally aspirated 3.2-litre V6 engine with a power output of 184 kW. It rockets from zero to 100 km/h in 5.7 seconds and reaching a top speed of 250 km/h.
Both engines are equipped with a six-speed manual gearbox. On request they can be combined with the dynamic S-tronic dual-clutch gearbox.
Whereas the four-cylinder engine comes with front-wheel drive, the V6 distributes its power across both axles by way of the quattro permanent four-wheel drive system.