There is nothing dramatic or revolutionary about the way the TT TDI is put together. Just as with every other TT variant, the car is still manufactured using Audi’s clever spaceframe construction method that mixes aluminium and steel. This exploits the lightness and strength of aluminium, but uses high-strength steel for the more complex shapes, particularly around the front and rear axles.
The engine is also a known quantity. We’ve already sampled the new 2.0-litre common-rail motor in a variety of Audis and Volkswagens with various power outputs, and found it to be smoother and more linear in its power delivery than the single-unit injection pumpe-düse diesels of old.
There is no front-wheel-drive option, Ingolstadt’s engineers presumably (and not unreasonably) fearing that 258lb ft of torque from just 1750rpm would be a little too much for just two driven wheels. Instead, you get a Haldex-controlled quattro four-wheel drive system like in other quattro-badged Audis.
Although it channels 85 per cent of drive to the front wheels under normal circumstances, it can put up to 100 per cent of drive to whichever axle is most able to cope with the power.
It is a shame, however, that the gearbox is so conventional. There is no twin-clutch option (DSG in Volkswagen-speak, or S-Tronic in Audi’s language), the only gearbox available being a conventional
six-speed manual unit.
But although all the individual component parts of the TT TDI present nothing particularly new or radical, the way they are mixed together makes the TT diesel pretty special. In fact, we reckon that as a four-wheel-drive turbodiesel coupé with a hybrid aluminium spaceframe chassis, the diesel TT is unique among series production cars.