The production model (internal designation Typ 8N) was launched as a Coup? in September 1998, followed by a Roadster in August 1999. It is based on the Volkswagen Group A4 (PQ34) platform as used for the Volkswagen Golf Mk4, the original Audi A3, the koda Octavia, and others. The styling differed little from the concept, except for slightly reprofiled bumpers, and the addition of a rear quarterlight windows behind the doors. Factory production commenced October 1998.
Mechanically, the TT shares an identical powertrain layout as its related Volkswagen Group platform-mates. The TT uses a transversely mounted internal combustion engine, with either front-wheel drive, or 'quattro' on-demand four-wheel drive. It was first available with a 1.8 litre inline four cylinder 20-valve turbocharged engine in two states of DIN-rated power outputs; 180 PS (132 kW; 178 hp) and 225 PS (165 kW; 222 hp). The engines share the same fundamental design, but the 225 PS version features a larger K04 turbocharger, an additional int
