For my daily commute of 22 miles each way, I average 44mpg, irrespective of driving mode. It's fractionally better in eco (obviously) but not enough to make me worry which mode I'm in.
The commute is 2 town/city sections with 12 miles of dual carriageway in between, at rush hour.
On a long trip back from North Wales at the end of August I got 56mpg in eco - that was a lot of country A/B road with a fair number of junctions and a fair amount of traffic, so I was happy with that figure.
Still beats the 24 mpg I was getting daily in my Merc SLK
I get 400-450 miles / tank, but the readout will typically indicate a range of 490 miles at fill-up.