The BlueMotion models from VW are the fuel mizzers of the brand.
Differences from other, "normal" Passats, Golfs , etc. are a longer 5th gear, slightly better aerodynamics (IIRC the car sits a bit lower than the regular model) and low resistance tires.
The same 1.6 CR TDI also comes in a Golf Blue motion which uses even less fuel than the Passat. I wonder why they did not choose tha Golf for the test, the results would have been even mores spectacular.