The 2012 A3 holds 4.2 quarts (4.0 liters). That car has the CBEA engine. The 2012 Jetta TDI has the CJAA revision of the same engine, but it holds 4.3L (4.5 quarts). The spec sheet on the VW site is just plain WRONG. Go by what the owners manual states, not by what the website states.
'10 Jetta 2.0 TDI, DSG