Road Test: BMW 3 Series 320i xDrive M Sport 4dr Step Auto

They're the standard backdrop to your average winter wonderland outside broadcast. Some frozen-to-the-core reporter attempts cheeriness in front of sledging children before copping a snowball to the earhole, while behind him, you, the geeky petrolhead, can clearly identify a rear-wheel-drive BMW flailing amateurishly on a millimetre of ice. Maybe Audi stalks regional TV crews with a purpose-bought 3-series just for such eventualities.

Well, no more. BMW has clearly had enough. Here we have a BMW 320iX, or 320i xDrive as BMW would prefer it to be known. It's at the pointy end of a range that expands in March with the arrival of 4WD saloon and estate versions of the 320d and 330d, plus the 120d hatchback.

OK, so for 360 days a year, you'll bemoan the fact you spent an extra £1,535 on a car that is 85kg heavier, plus 4.8mpg and 12g/km CO2 less efficient than a standard 320i, but just imagine how smug you'll be on the other five. And all thanks to a tiny little xDrive badge on the rump. And the small matter of a 4WD system that sends 60 per cent of its power to the rear wheels mostly, but is able to send up to 100 per cent to either axle if needs must, and can also brake individual wheels to improve stability and traction.

The engine it's mated to here isn't the 3-series's best. The 2.0-litre four-cylinder turbo does the job, but is neither tuneful nor especially interesting, and never feels 0-62mph in 7.4secs fast. But we're here to talk about the 4WD system, which is quite brilliant. Mainly because it's almost impossible to detect it at work.

The iX feels as fluid and natural down a country road as the standard 3, with none of the tightness, stiction, steering corruption and nose-heaviness that can signal a car with front driveshafts as well as rears. So maybe the weight and frictional losses have marginally dulled performance and made it a hair's breadth less sparkly, but this is a great car to drive, and the extra sense of all-weather security is there at all times of year.

Boot it in tight corners, and you can feel the power transfer, the front end digging in and pulling you through smoothly and surreptitiously. This is not some Impreza-style hardcore physics-bender, instead, it's a benign confidence-inducer. Top it off with a set of winter tyres, and go find a snowbound TV crew.