I have a Focus, 57 plate and while its comfortable, looks ok, cheapish to buy, cheap to repair (reputedly) mine being relatively low spec (Focus Style 1.6), i feel its underpowered and you find yourself frequently losing speed if you dont concentrate. Accordingly i find it not that economical...45mpg through the winter and thats with driving like a saint,really really carefully. I suspect if you drove it 'normally' you'd be in the high 30s to 40mpg. Drive it round town and the MPG plummets.
Summer driving should be better.
I did wonder if i'd brought one with the wrong engine..but it seems many Focus owners, whatever engine, feel there not that economical.
If economy isnt your primary consideration, you could do worse.