They may do 70mpg in the EC lab tests, but they won't do 70 used as a business car in real life unless you can afford to spend an extra hour or two a day on the road driving for maximum economy. Reckon on 55 - 60 driving reasonably sensibly. I did actually average 55mpg over 8,000 miles in a first generation Focus ECOnetic 1.6 TDCI 110 without stop start, that was just a coupe of mpg shy of the EC 'combined' figure.

You don't have to worry about all the very high replacement parts costs of a diesel in years 3 - 6 because either your employer will have replaced the car by then or your employer or the lease company will have to bear those costs. For true consumption figures obtained by real people rather than lab technicians.

See the Real Life Fuel Economy Register at: www.honestjohn.co.uk/RealMPG