I have a picture of my MKIII Dci 106bhp showing 78mpg. This was done driving 20 miles, filling up with diesel, resetting the trip computer, and then driving back 20 miles at 50mph. My car is lucky to see 52mpg in proper brim to brim filling!!
I used to get in MKII Dci65 a combined 56mpg in town and normal driving.