BMW 4 Series review - Do chassis tweaks make the 2017 4 Series a real drivers' car? - MPG and running costs

The whole rationale behind dropping normal aspiration for forced induction is that you get the same power and performance as before, yet with much better parsimony. This is true of the 4 Series derivatives, which turn in economy and emissions figures that almost beggar belief – even if you accept that the NEDC-generated figures will be impossible to attain in the real world.

In short, no 4 Series emits more than 200g/km of CO2 (the Gran Coupé 440i model is rated at 159g/km), while even the 440i Coupé manual can return 36mpg. At the other end of the scale diesel Coupé 420ds can achieve 67mpg, while CO2 emissions get as low as 118g/km on a 418d auto Coupé. Benefit-in-Kind rates run from 17 to 31 per cent across the range.

Naturally, fitting xDrive has an adverse impact on economy and emissions model-for-model (it brings a 70kg weight penalty), but fitting an auto does not: the ZF 8HP units can deliver better ‘green’ figures than the six-speed manual gearbox.

Owners can opt for a Service Inclusive payment, which covers all costs for the first five years or 50,000 miles for a one-off lump sum at purchase time, while there’s a three-year/unlimited mileage warranty as standard on new BMWs.