To tell you the specific engine size, please tell me:
* The trim level of the A6: (e.g., 2.0T, 3.2 FSI, 4.2 FSI, etc.)
* The type of engine: (e.g., gasoline, diesel)
* The market: (e.g., US, Europe, Asia)
Once I have this information, I can provide you with the correct engine size.