BMW 5 Series saloon (2010-2016) - MPG, running costs & CO2

BMW 5 Series MPG & CO2

In entry-level SE saloon form, both the BMW 5 Series 520d and 518d return 65.7mpg and emit 114g/km of CO2 – and that’s whether you go for the standard six-speed manual or the superb eight-speed automatic gearbox (a recommended, if quite expensive, option). However, and this applies most cars, the size of the wheels can have an implication on the car's CO2 emissions. Check this out before you buy, in case they're higher than expected.

With sub-120g/km CO2 emissions, the 520d will cost you nothing in the first year for road tax, followed by £30 a year after that, while business users will pay a Benefit-in-Kind (BiK) rate of 22%, 1% more than an Audi A6 2.0-litre TDI 190 Ultra.

The slightly more powerful 525d is an interesting choice, but its running costs are just that little bit higher, making it an awkward halfway house. If you've some more money to spend and fancy something more powerful, then the 530d and 535d, both powered by a 3.0-litre six-cylinder diesel engine, provide stunning performance. Impressively, they still return up to 55.4mpg economy, with CO2 emissions as low as 134g/km for road tax of £130 a year.

Petrol models are harder to recommend, because unusually they cost more than the equivalent diesel engine. That’s a shame, as they’re reasonably efficient and nice to drive, but the price premium coupled with the inevitable increase in fuel bills and road tax will be too much to for all but the most hardened diesel sceptics to bear.

The exceptions are the big-engined models – the 550i and M5. Both are powered by a 4.4-litre twin-turbo V8, with 449bhp and 552bhp respectively, and will cost a small fortune to run. The official figures for the M5 are 28.5mpg and 232g/km of CO2, but use a fraction of its capabilities and you’ll get far less from a tank of fuel than that.

BMW also offers a 5 Series ActiveHybrid petrol-electric model, but the focus is more on performance than efficiency, which is why fuel economy is a slightly disappointing 44.1mpg.

Insurance group

Of course, it’s not just fuel economy and road tax brackets that contribute to the running costs of a car ­– insuring it can be a costly business, too. The 520d SE falls into insurance group 34 out of 50, so premiums will be on the high side of average.

Warranty

Every 5 Series comes with BMW's standard three-year/unlimited-mileage warranty, which is what you'd expect from a car in this class. Extended warranties are also available.

Servicing

To cut down the cost of servicing, BMW also offers a very reasonable £475 servicing pack, which provides five years or 50,000 miles of maintenance – whichever comes first.