I have the petrol version.
I haven't done any proper test or calculation but, if it helps, after 2500 miles the mpg reading on the car computer says 47.7mpg. Best fuel consumption on a single trip 57mpg.
1.5 dci - best so far 75 mpg, keep it below 65 on motorway driving you will get close to 70 mpg, anything over 75 mph will drop down to low 50's. Local suburban driving with bits of traffic mid 40's to mid 50's
We are averaging 59mpg on our Dci which is allot better than the same engine we had in the juke! nearly an extra 10mpg I think the gearing is different to the juke which has made for allot nice motorway cruiser!