Mercedes-Benz B-class review - Practical people-mover not Mercedes' best effort - Mercedes-Benz B-class MPG and running costs

If low running costs are all that matter, and you can live with the official 143 mile range (likely lower in the real world), then it's worth considering the all-electric B-class, tagged B 250e. Saying that, at a minimum price of £27,275 (including the government's £5000 plug-in car grant), it's not cheap to buy.

The diesel engines are probably the best option for most. The B 180d and B 200d return combined economy figures of 68.9- and 65.7mpg respectively, though when fitted with an auto they return an identical - and rather impressive - 70.6mpg. The B 220d (auto only) isn't far behind at 67.3mpg, though that drops to 56.5mpg in the 4Matic four-wheel drive car.

The petrol versions shouldn't be immediately discounted, however, as they're cheaper to buy in the first place and will suit low-mileage drivers. Both B 180 and B 200 return 50.4- and 52.3mpg when fitted with a manual and automatic gearbox respectively.

Emissions ratings vary from as 104g/km in certain versions of the B 180d and B 200d to 132g/km in a few of the petrol cars, which means annual road tax of as low as £20, or as high as £130. Insurance ratings are 15 to 24 and Mercedes-Benz allows buyers to spread the cost of fixed price servicing with its Service Care offering.