Two generations of A3 exist, both based on the Volkswagen Group A platform, which they share with several other models such as theVolkswagen Golf, Caddy and Touran,  Audi TT, as well as SEAT Toledo, SEAT León, and Škoda Octavia.
The Audi A3 is a compact car produced by the German automaker Audi since 1996.

TECHNICAL CHARACTERISTICS

 There are two generations of Audi A3: Audi A3 (8L) and Audi A3 (8P)

 Audi A3 (8L) appeared in 1996 and was produced till 2003. It was assembled in Ingolstadt -Germany and Curitiba - Brazil. Audi A3 has 2 types of body style: 3-door and 5-door hatchback. It uses Volkswagen Group A4 (PQ34) platform. Audi A3 (8L) has 4 types of engines (The engines used are the same as for many other cars in the Volkswagen Group): 1.6 L I4, 1.8L I4 20v, 1.8L I4 20v Turbo and 1.9L TDI I4.  Its transmission can be: 5-speed manual, 6-speed manual, 4-speed automatic and 5-speed automatic. Wheelbase for Audi A3 can be 2 kinds: 2,513 mm (98.9 in) and quattro: 2,518 mm (99.1 in). It’s height is 1,423 mm (56.0 in), width - 1,735 mm (68.3 in). Audi A3 (8L) is related to Audi TT (8N) Mk1, Škoda Octavia Mk1, VW New Beetle, VW Jetta Mk4, VW Golf Mk4, SEAT Toledo Mk2 and Related SEAT León Mk1. Aud's Electronic Stability Programme (ESP), brake force distribution and traction-control computer became standard equipment in some countries.

 Audi A33 (8P) appeared in 2003 -  second-generation of the A3. It obtained a redesigned and more spacious interior. Audi Aw (8p) was launched only as a three-door hatchback, it featured a new automobile platform (the PQ35 platform), with four cylinder engines, standard six-speed manual gearboxes (except on the base 1.6) and new petrol engines with Fuel Stratified Injection (FSI). Audi A3 (8P) is assembled in Ingolstadt - Germany and Brussels - Belgium. It has three types of body style: 3-door hatchback, 5-door estate and 2-door convertible. Audi AA3 uses petrol and diesel engines so, petrol engines are: 1.6 L I4, 2.0 L I4, 1.8 L I4 Turbo, 2.0 L I4 Turbo, 2.0 L I4 Turbo and 3.2 L VR6, diesel engines: 1.9 L I4 TDI and 2.0 L I4 TDI.. Its fuel capacity is  55 L (12.1 imp gal; 14.5 US gal). Audi 3A is produced with 5-speed manual, 6-speed manual, 6-speed automatic, 6-speed automatic S-Tronic and 7-speed automatic S-Tronic transmissions. Its wheelbase is 2,578 mm (101.5 in), width - 1,765 mm (69.5 in) and height - 1,420 mm (55.9 in). Its length is for 3-door Audi A3 (8P) 4,215 mm (165.9 in) and for 5-door Adi A3 (8p) - 4,285 mm (168.7 in). Its maximum loading on the trunk is 1855kg. Aufi  A3 (8P) reaches top speed on 238 kmph. In general this model line uses 9,9L of fuel in the city and 5,6L on the highway, and its average consumption is 7,2L.

 We can also mention that Audi A3 (8P) is related to udi TT (8J) Mk2, SEAT León II, SEAT Altea, SEAT Toledo Mk3, VW Jetta Mk5, VW Golf/Rabbit Mk5 and Škoda Octavia II