The 316d makes a lot of sense. It’s as good to drive as any other 3-Series, with a smooth diesel that pulls strongly despite its relative lack of power. Spec isn’t luxurious but build quality is first class, while low running costs will appeal to private and fleet drivers alike. Those looking for a more powerful and frugal 3-Series could wait for next year’s 320d EfficientDynamics, but in the meantime the 316d makes a strong case for itself.

How low can BMW go? With economy of 62.8mpg and CO2 emissions of 118g/km, the 316d is the cleanest 3-Series yet. But can it still claim to be the ultimate driving machine?

Well, power comes from a detuned version of the 2.0-litre four-cylinder turbodiesel found elsewhere in the range. A meagre-sounding 114bhp is backed up by an impressive 260Nm of torque, resulting in a respectable 0-60mph time of 10.9 seconds.

As with all four-cylinder 3-Series models, the 316d gets a raft of fuel-saving technologies including brake-energy regeneration, stop-start and a gearshift indicator. These help it to achieve a theoretical range of up to 800 miles on a single tank.

On the move, the engine feels smooth, and stronger than its horsepower figure suggests. The generous torque makes cruising easy, while the stop-start system cuts in and out unobtrusively.

It might be the slowest car in the line-up, but in terms of steering feel and dynamics the 316d is just as good as its stablemates. Softer suspension than models higher up in the range give it a surprisingly comfortable ride, too.

It is available only in basic ES spec, so luxuries are sparse – although it has air-con and a multi-function leather wheel. The cabin is beautifully built, and brushed aluminium trim gives it a fresh, modern look.

Thanks to the low emissions, private customers will have to pay only £35 road tax. Company car drivers will be even better off: a 13 per cent benefit-in-kind rating offers significant savings over a 318d.

These bonuses will help to offset the price tag, which at £23,330 seems a lot to pay for a 114bhp diesel saloon. Looking ahead, March will see the introduction of an even more frugal model, the 320d EfficientDynamics. This will be faster thanks to its 161bhp engine and – with 109g/km of CO2 and 68.9mpg combined – cheaper to run, too.

Rival: Audi A4 TDIe
For the same money, the 136bhp 2.0 TDIe offers better performance, nearly the same economy and standard parking sensors. But it doesn’t involve drivers quite like the BMW.