BMW X6 M50d (2012) leads facelifted X6 range

BMW is facelifting its most controversial model, the X6. And what better way of tidying up this coupe-cum-SUV than adding a diesel M version?

The new X6 M50d is among the first of a new range of stop-gap M models to slot between the full M GmbH cars and the trim-level M Sport models. It'll sit alongside the new BMW M550d xDrive also unveiled today.

It has a new upgraded version of the same 3.0-litre straight six TwinPower turbodiesel, with greater boost from three turbochargers to deliver 376bhp and a monstrous-sounding 546lb ft of torque.

It's the most powerful diesel BMW has ever built.

Oh yes. This is another fast four-by-four to spark fierce debate in chartrooms up and down the land. It hits 62mph in 5.3 seconds - enough to embarrass many Porsches.

BMW defends such high-riding lunacy by pointing out that the new X6 M50d also averages 36.7mpg and CO2 emissions stand at 204g/km.

BMW has indeed refreshed the X6. As you'd expect from any of Germany's premium car manufacturers, this is a modest facelift. Any untoward blinking, and you may indeed miss it.

The chrome grille is a little wider and the detail bars are new; the foglamps are repositioned; active LED headlamps are now available; out the back, you'll find a rear lamp cluster with subtly different graphics and those now-trademark horizontal light bars that make the latest 5-series so distinctive at nighttime.

It's not all cosmetic. Much of the front-end tidy-up in fact improves engine cooling and breathing, while new flaps beneath the front apron are designed to boost stability.

Naturally. If you've got a spare £85,680 lying down the back of the sofa for an X6 M. The new super-diesel SUV-coupe-thing X6 M50d costs considerably less at £62,260, landing in UK dealerships on 16 June 2012.

You can order the same spec X5 M50d for a couple of grand less; it wears a price tag of £60,325 and has the same breathed-upon 3.0-litre twin-turbodiesel.

By Tim Pollard