BMW’s third-generation 1 Series brings with it more interior space, a sportier design and a reduction in the length of what was an oversized bonnet in previous incarnations.

These will be welcome improvements alongside lower emissions, more power and improved fuel efficiency. There are new driver assistant systems, too, and the introduction of the fab BMW head-up display, which is still probably the best in the business.

But there’s been another, more radical change to the 1 Series which may have petrolheads reaching for their fuel pump triggers.

BMW, creator of the Ultimate Driving Machine, had always delivered rear-wheel drive vehicles because of their supposed increased driving pleasure. But now, shock horror, the 1 Series is strictly front-wheel drive.

Now this will be seen as a major departure in some circles, but the truth is that BMW’s research showed that more than three-quarters of 1 Series owners did not know or care whether their car was front or rear-wheel drive.

Engineers were confident that the driving pleasure would not be diluted by making the change, and the benefits of increase cabin space made the switch a no-brainer.

Most 1 Series customers will undoubtedly opt for one of the two bedrocks of the brand, the 118i petrol or 118d diesel.

I tested the Sport version of the 118d, powered by one of the smoothest two-litre diesel engines out there, featuring two-stage turbocharging. Even at low speeds it is uncannily quiet, and at cruise level I defy anyone to sense whether it is a diesel or petrol engine under the bonnet.

It will deliver up to 60mpg too, with C02 emissions only a little north of 100 grams per kilometre.

Agile and refined in equal measures, the 118d Sport hits 62mph in only 8.4 seconds. With virtually perfect weight distribution, it grips very well to the road thanks to some clever technology handed down from the i3 model.

This new 1 Series is just a tad shorter than its predecessor but a shade taller and wider.

The big difference is on the inside. The front-wheel-drive architecture with transverse engines and a lower centre tunnel offers the occupants more space, especially to those in the rear seats where there is an extra 33 millimetres of knee-room available. Rear passengers also enjoy 13 millimetres more elbowroom, while the driver and front passenger get an extra 42 millimetres. Luggage compartment capacity rises by 20 litres to 380 litres, and when the rear seat bench is folded down the capacity increases to1,200 litres. An electrically operated tailgate and panoramic roof with electrically operated roller blind are new options.

The 1 Series, powered by three-cylinder and four-cylinder engines with a choice of three diesel and two petrol engines, is available in SE, Sport and M Sport trims as well as the range-topping M135i xDrive. But beware of the huge array of options that may well take the cost of your 1 Series car from a starting point below £25,000 to one above the £30,000 mark.

In the BMW 116d, BMW 118d and BMW 118i, the engine’s power is delivered via an upgraded six-speed manual gearbox. Eight-speed Steptronic Sport transmission is fitted as an option in the BMW 118d and as standard in the 120d xDrive and the M135i xDrive.

Benefiting from an array of driver assistance systems that combine camera images and data gathered by radar and ultrasonic sensors to either alert the driver to hazards or minimise the risk of an accident by means of corrective braking and steering, the 1 Series even offers a reversing assistant to get you out of tight spots such as multi-storey car parks or entrances.

And the BMW Intelligent Personal Assistant allows drivers to operate their car, access its functions and obtain information simply by speaking.

Ultimately, this is a better 1 Series in so many ways. Technically brilliant, a joy to drive and now a little more practical, it may be a little shorter but it will have extended its appeal.

The lowdown

BMW 118d Sport

Price: from £26,565 (range from £24,430)

Engine: 2.0-litre twin turbocharged four-cylinder diesel producing 150hp

Transmission: Eight-speed dual-clutch automatic

Performance: 0 to 62mph in 8.4 seconds; top speed 134mph

Economy: 60.1 to 51.4mpg combined

CO2 emissions: 109g/km

Star ratings

Performance: ****

Economy: ****

Ride/Handling: ****

Space/Practicality: ****

Equipment: *****

Security/Safety: *****

Value for Money: ***