Audi has given its latest insight into plans to extend the third-generation TT family with the unveiling of a new 395bhp, 2.0-litre four-cylinder engine-powered five-door concept called the TT Sportback.
The practical new Sportback, revealed on the eve of the Paris motor show, is the third conceptual derivative of the TT to be aired by Audi in 2014. It follows the stylish TT Allroad revealed at the Detroit motor show in January and the high-riding Offroad shown at the Beijing show in April.
Although all three variants are billed as concepts, they are said to closely preview the new liftback, shooting brake and SUV models that could complement the existing coupé and roadster in a five-strong range of TT models within the next three years.
"In our TT Sportback, we are revealing a new member of a potential TT family," said Audi research and development boss Ulrich Hackenberg. His comments follow similar accounts of the TT Allroad and TT Offroad, the latter of which Hackenberg has described as a "glimpse of a new model in the future TT family".
The TT Sportback draws its styling inspiration from the latest TT coupé, and comes with heavy influences of the Bauhaus design lineage that has shaped the look of the Audi line-up since the mid-1990s.
While it is evident that it is not simply a stretched version of its three-door TT coupé sibling, it is clear from the similarity in appearance that the new five-door is intended to be a member of the same family of models.
Among its more prominent elements is a bold six-corner grille set within a heavily structured front bumper. The front end also features a clamshell-style bonnet that wraps into the flanks and trapezoidal-shaped headlights with distinctive laser high beam projectors that are activated at speeds above 37mph.
The new model retains the prominent wheel arch flares that have been a feature of the TT since its introduction to the Audi line-up back in 1996. They are filled out with substantial 10-spoke 21-inch alloy wheels shod with 255/30 tyres.
A defined shoulder line, referred to by Audi as the 'Tornado' line, runs the entire length of the flanks, from the trailing edge of the headlights through to the tail-lights. Four frameless front-hinged doors provide access to the cabin. A shallow glasshouse is stretched with the addition of a third window at the rear, while the B-pillar is fixed in the interests of structural rigidity.
Holding true to the layout of the TT coupé models, the new TT Sportback features a liftback-style tailgate styled in similar fashion to that gracing the Audi A7. The rear also features new slimline LED tail-lights and twin oval-shaped tailpipes set within a deep rear bumper.
At 4470mm long, 1890mm wide and 1380mm high, the five-door liftback is 290mm longer, 58mm wider and a scant 27mm lower than its three-door sibling. This makes it just 14mm longer, a considerable 94mm wider and some 36mm lower than the German manufacturer's existing A3 saloon.
Underpinning the new car is a new variation of parent company Volkswagen’s MQB platform.
To accommodate the rear doors and provide adequate rear seat accommodation for two adults, it receives a 2637mm wheelbase that is 125mm longer than that of the TT coupé and 7mm longer than the A3 sedam.
The added width in the body also suggests that it uses wider tracks front and rear than either of its siblings, although the exact measurements are yet to be made official.
To keep weight down and achieve rigidity levels described as being similar to its two-door sibling, the body structure uses a variety of different materials. The front section is made from steel, the floor uses hot-formed high-strength steel elements in differing gauges and the outer skin, including the bonnet, four doors and boot lid, are aluminium.
The interior of the TT Sportback is based closely on that of the new TT coupé. The two cars share the same high-quality dashboard, digital instruments, centre console, switchgear, multi-function steering wheel, heavily bolstered front seats and carbonfibre-look trims.
Among the highlights is Audi's new virtual cockpit display, which consists of a 12.3-inch TFT monitor set within the instrument binnacle. It works in conjunction with a rotary control placed on the centre console and boasts a customisable display.
Resisting the temptation to turn the TT into a fully fledged five-seater, Audi has given the Sportback concept individual rear seats with integrated headrests, providing it with accommodation for up to four. The rear seats, which are divided by an armrest and storage compartment, can be folded down to extend luggage capacity.
The TT Sportback is powered by a heavily tuned version of the Audi-developed EA888 engine. Mounted transversely up front, the turbocharged 2.0-litre four-cylinder unit is claimed to produce a heady 395bhp at 6400rpm, endowing the new concept with 89bhp more than the new third-generation TTS coupé.
By comparison, the similarly conceived turbocharged 2.0-litre four-cylinder petrol engine used by the Mercedes-Benz CLA45 AMG produces 355bhp at a slightly lower 6000rpm rpm.
Audi says the aluminium block engine has undergone extensive modifications to realise a specific output tantalizingly close to 200bhp per litre.
Included is a new turbocharger running a maximum boost pressure of 1.8 bar, a reworked cylinder head with increased gas flow rates, revisions to the variable camshaft adjustment and the two-stage variable valve-lift system, indirect injection on part throttle loads for improved combustion and an exhaust manifold embedded in the cylinder head for improved thermal qualities.
The heady reserves are channelled through a six-speed S-Tronic dual-clutch automatic gearbox with remote steering wheel-mounted paddles and a multi-plate clutch four-wheel drive system mounted within the rear axle for improved front-to-rear weight distribution.
Audi has yet to put forward a weight claim or gearing details for the TT Sportback. However, the German car maker’s own computer simulations point toward a 0-100kph time of just 3.9sec. This is 1.1sec faster than the TTS coupé and not far off the fastest-accelerating Audi production car to date, the R8 5.2 V10 Plus, which is claimed to achieve a time of 3.5sec.
Audi is not prepared to divulge a top speed for its latest concept. However, it is safe to say any possible production version of the TT Sportback would be limited to 250kph in line with its more sporting TT coupé sibling.