My Passat is the 140PS 2.0 TDi and in my opinion is pretty poor on fuel economy. 30-40mph town driving returns around 35 mpg. On a motorway run it's up to around 40 mpg. You have to drive it very carefully to get 45+ mpg.
The last Passat was the 130PS 1.9 TDi and that would return 40-45 mpg around town and 50 mpg on a run.
The new Passat is very heavy (has to have extra load reinforced tyres) and with 235/45/17 tyres, the rolling resistance is probably quite high, hence the poor fuel consumption.
I found the interior noise levels were quite high also on that engine when fitted to the Touran Martin