Mine is brand new and now has 1100k on the clock (so still tight) and running hubs locked (to run in) and the aircon on most of the time im getting 700k to a full tank till the fuel light comes on. so it should get better once run in a bit.
This is for a 2.5L Diesel. D22
D22 04 3lt turbo-diesel with DP chip set on 8 3"mandrel-bent exhaust and 3 hiclones fitted city 10.0lts per 100kms country 8.5 and towing a camper trailer around 12 to 13 lts per 100.