2.0 in mixed driving, you'll get about 27/28 mpg on average doing 25/50/25 town/A/motorway. The twin sparks simply aren't fuel efficient engines.
My daily commute is around eight minutes through town (lots of traffic lights on the way out, and junctions), followed by a 'good' b-road run for five minutes and a rural b-road for another six.
Once I'm out of town I get it into fifth and average 60-70 mph.
Watching the computer can be quite scary (I've got the connect+ kit, so it's almost a mathematicians wet dream...)
The computer generally shows an average of around 30mpg for my 2.0 over successive tank of fuel. If I slow down (a lot) it comes in at around 33 mpg. For the sake of three mpg it's hardly worthwhile...
If I do motorway runs it generally comes out with around 36mpg over the course of a 90 mile trip - which isn't too bad considering how often I 'make use' of that engine on such journeys
However, with a lot of inner-city driving, the AVERAGE plummets to around 22mpg, or less.
I have to say, though, that I don't trust the computer - the dash tacho never matches up with the connect+ one over extended periods, which means the sums it's doing have to be out too.
Ultimately, I'm of the opinion that trying to get the best mpg is a lost cause - it'll strip all of the fun out of your journey.
By all means, keep an eye on it - and make sure it doesn't get silly - but it's far better to accept that you've got an engine with the capacity of two bottles of Schweppes lemonade - and that's why it goes like the clappers.
If you're determined to get more out of every gallon, you need to get something more equivalent to a can of Tesco's own brand cola....