BMW 3-Series Touring: Running costs

320d proves a frugal choice

One of the surprises in running the 320d has been the running costs - or rather the lack of them. Admittedly, the fuel consumption figures have not been as impressive as the official figures suggest they should be, but that is more down to the type of driving I normally do such as commutes on country lanes.

Determined to find out what the 2.0-litre diesel was really capable of, I lined up a long drive to Newcastle from Peterborough to see if a 300-mile plus trip on dual carriageways can really up the average fuel consumption.

I kept to 60-70mph and tried to eek out the fuel by avoiding any unnecessary braking or heavy use of the throttle. The in-car mpg reading eventually climbed and steadied at just over 64mpg, which meant a tank of fuel would keep the car going for over 859 miles.

If you do a lot of motorway miles then choosing the diesel BMW justifies the extra cost over the petrol. That's why it pays to check that a diesel version will pay for itself in the long term.

Throw in annual road tax of £150 and an insurance cost of £556, and the running costs can seem quite affordable. Until you compare it to an Audi A4 2.0 TDI SE Avant (the 170bhp version). The A4 sits in a lower road tax bracket and will set you back just £125, but it isn't as fuel efficient with an average of 51mpg versus the BMW's 58mpg.

Current mileage: 9723

Average mpg: 64.4