my mates just got a new passat eco thing, 1.6 derv. has done 850 miles to a tank, i think he said 58mpg average. but it still needs running in, so should only get better.
my work vivaro van seems to be doing about 600 miles to a tank, ive not yet done a full tank on it tho as i only got it sunday with 3/4 of a tank, and filled it up tuesday.
my old van would see 500 miles to 80L, but that thing got its arse handed to it ALL day