I have a 2014 TCE90 and on average I get ~44mpg. About 39-40mpg for urban stop/start driving, 50mpg on long A road and motorway runs.
That said, I don't pay any attention to what the onboard computer says! When I fill up I make a note of the number of litres delivered and the miles covered, before resetting the trip meter. I use a spreadsheet to keep a record of all fill ups (yes, I am a bit sad, but it did justify the extra cost of "premium fuel" through improved mpg) and a quick calculation (miles travelled)/(litres of fuel/4.546) gives you your accurate mpg figure.