ABT Sportsline, the official tuner for Audi models, brings to light a tuning kit for the current diesel-powered variants of the A6. The germans took the current ECU of the 2.0 liter TDI engine, and remapped it for an increase in power. This means a increase of power from the standard 174 hp to 202 hp.
  
ABT also modified the more powerfull diesel versions of the A6. The V6 3.0 liter turbocharged variant gets 266 hp from the standard 201. For the 245 hp version, ABT prepared 296 hp. Finally, the most powerfull diesel, that offers 313 hp, reaches a total of 355 hp.
 
In addition to the power tune, ABT offers up a sports suspension kit, plenty of alloy wheel options sized from 19- to 21-inchs, performance brakes, and an aero body kit. The body kit comes with side skirts, a front and rear spoiler and a rear apron with exhaust tips.

Source: Audi