The BMW X6 looks like the outcome of a collision between the German company’s 6-series coupé and the X5 off-roader. And that’s because it is, at least in design terms. BMW claims it’s an entirely new class of car and has even given it a name – the sports activity coupé (SAC). You may laugh but from some some angles the odd appearance works – the X6 can look dramatic, even handsome, especially from the rear. But from other angles it suggests something SsangYong might have knocked up for Korean customers hooked on repeats of Dynasty.

On paper it almost shares its dimensions with the X5, and although it looks compact from a distance it really is one of the biggest cars on the road. Not so from the inside, though: a tapering roofline demands sacrifices of the passengers. The X6 will accommodate only four adults in comfort as it has no occasional middle seat, and rear headroom is compromised for anybody much over 6ft; rear vision isn’t great and luggage space is positively tight.

The dashboard is pretty much lifted intact from the X5, but that’s a good thing. The layout, look and feel of the fascia and the snuggly, enveloping driving position are all typically brilliant BMW, and the cabin itself exudes an aura of high quality and solidity.

The two rear passengers each get an individual chair complete with a centre console for drinks, and a separate armrest. It’s cosy, but if you’re as tall as me you’ll find your hair sticking to the roof and legroom to be sadly lacking. Without doubt the best seat in the house is up front – the one opposite the steering wheel.

BMW promised that the X6 would provide the best drive of any off-roader it has yet created. Thus the centre of gravity is lower than the X5’s, and it has a marginally wider rear track, both of which make it feel secure and planted. The real showstopper lies beneath the bonnet, though, as the flagship X6 is the first BMW to use the company’s new 4.4 litre twin-turbo petrol V8. Because it has two turbos, each supplying four cylinders, they can be smaller and more responsive, so eliminating turbo lag, and ultimately more power is developed from fewer cubic inches. For the record the new engine serves up 408bhp and 442 lb ft of torque and is good for a claimed 0-62mph time of 5.4sec and a (limited) top speed of 155mph. Power is delivered via a six-speed automatic transmission with shift paddles at the steering wheel.

The company’s existing xDrive technology manages power distribution between front and rear axles, but BMW has added dynamic performance control to it, which monitors yaw, speed, steering input and lateral forces and works out how best to dish out power between the two rear wheels. So if the car is understeering through a left-hand corner, more torque is delivered to the offside rear wheel, which tightens the cornering line and reins in the understeer.

It works superbly: on a wet handling circuit through a slalom course the X6 displayed an astonishing willingness to change direction without understeering, and on a dry circuit it was rapid and beautifully balanced.

Its engine is glorious. It makes an old-school V8 grunt that starts out guttural and, once the rev counter has swung past 6000rpm, ends up sounding like the hammers of hell. Regrettably the V8 won’t be available until November; from its May launch the X6 will have the excellent 3 litre twin-turbo straight six, and two turbo diesels.

So BMW’s newest delivers on its driving promise without even needing a qualifying “for a 4x4”. Its hybrid coupé/off-roader styling may look strained, but it is at least different. Good though the X6 is, however, you can find a better driving experience with a number of executive saloons (the Merc CLS leaps to mind) that also provide a stand-out appearance.

So the X6 is a very good car, and with it BMW has cleverly carved itself a niche within a niche. You should think long and hard about exactly why you might want one, though, as many sacrifices must be made for that combination of nifty styling and commanding driving position.

Vital statistics

Model BMW X6
Engine type 4395cc, V8
Power/Torque 408bhp @ 5500rpm / 442 lb ft @ 1750rpm
Transmission Six-speed automatic with paddle shift
Fuel/CO2 22.6mpg / 299g/km
Performance 0-62mph: 5.4sec / top speed: 155mph (limited)
Road tax G (£400 a year)
Price £51,000 approx
Verdict Good to drive, but a compromise between coupé and 4x4

Date of release November (other versions of the X6 available in May)

The opposition

Porsche Cayenne GTS, £54,350
For It shouldn’t be this good to drive but is
Against An ugly thing; Porsche purists will laugh at you

Range Rover Sport 4.2 S/C HSE, £58,500
For Extremely able off road; great interior
Against Thirsty, heavy, footballers’ favourite