BMW X6 M50d 2015 Review

First, there was the X6; built off the bones, muscles and sinew of the X5 but with more grip, more (attempted) visual athleticism and less space. It was a car the world patently didn’t need but plenty of well-heeled buyers made the expensive decision that they wanted it anyway.

But now the pioneer of the swoopy, coupe-esque SUV doesn’t have those buyers all to itself anymore. There is its own Mini-Me (the X4) with a range of engines from the small to the strong. There will soon be the Mercedes-Benz MLC and Audi has two such beasties in the works to essentially overlap BMW’s family.

It takes some courage to spend as many millions as BMW did on the X6 and go it completely alone to create an all-new segment, especially when there are a handful of customers who get the X6 and the majority of the world’s drivers who don’t.

It has been less brave on the successor to its 2008 jaw-dropper, though, even though the car is slightly bigger in most dimensions. It’s 32mm longer (at 4909mm), 6mm wider (1989mm) and 3mm taller. It even keeps the outgoing car’s 1702mm rear track width, though the front is slightly narrower (1640mm) to help tune the handling and straight-line stability. It also has the same 85-litre fuel tank (applicable to both the petrol and diesel versions) and for those whose city basement car parks flood, it has a 500mm wading depth.

There is conservatism in the core engineering, then and there is also conservatism in the second-generation X6’s lines. It retains roughly the same silhouette and its bravest move is a turned-up crease line over the rear wheel.

Yet the X6’s designer, the Swede, Tommy Forsgren, doesn’t see it that way for the car he started sketching in 2010.

“The X6 was a pioneer and this new model is still one of the most expressive cars out there,” he insisted.

“We tried to make it more mature and grown up and focused on the premium aspects in the details and the surfacing. We tried to put more speed in the roofline. We wanted to put a lot of emotion in the car and the sculpting.

“The put so much emotion into it that first time we sent it to the techs they could not even open the door. That heavy sculpting is the kind of statement we wanted it to make.”

The point is more that you won’t mistake it for an X5 any more than you might mistake it for the outgoing X6.

For one thing, you’ll have less time to identify the new one, because the petrol V8 version hits 100km/h 0.6sec sooner (4.8sec) than its predecessor.

That’s broadly similar to the tri-turbo diesel’s advantage, too. The X6 M50d tested here is, like its predecessor, born (allegedly) of the half-step company between BMW and M, M Performance Automobile.

We also had a steer in the V8 50i, but the M50d delivers the best of both worlds, with speed that’s not far behind the thumping petrol motor and economy that’s far ahead of it.

It hits 100km/h in 5.2sec [0.1 quicker than its predecessor and 0.4sec behind the V8), but has had its fuel consumption trimmed by 15 per cent to sit at 6.6L/100km (exclusively through the addition of Start-Stop). The V8 chews through (an improved) 9.7L/100km.

Sure, the X6 50i’s 330kW of power trumps the M50d’s 280kW, but itV8's not-insignificant 650Nm gets crunched by the diesel’s 740Nm output.

It’s a thumper of a motor, with 2200 bar of injection [fuel] rail pressure, two small turbochargers and one large one, with all the gristle of a big V8 or V10 and very little trade off in noise-vibration and harshness compared to the V8.

And, at 2185kg, it’s only 15kg heavier than the petrol V8. Not that 2185kg is a lightweight (it’s 35kg heavier than its predecessor). It’s a huge number and it’s in the defiance of this number that the hefty thought processes that went into the X6 come through.

That tri-turbo diesel has been a pearl of an engine since the day it arrived in the M550d xDrive and it’s only getting better with age. Its redline is nominally 5500rpm and even though the power peak is at 4400rpm, it will shift itself at 5000rpm in automatic in its sport mode and a couple of hundred more if you force it via the manual mode.

It’s almost as smooth as the V8 when it’s cruising or on light throttle and it even sounds like a V8 when you attack it. It’s point-blank one of the world’s best engines (as well as one of the world’s most complex induction systems). It only really suffers against its petrol-powered stablemate in the free spinning nature of the V8 at high rpm.

There are other strong diesels, and there are other strong six-cylinder diesels, but none of them operate like this one. It’s almost like a relay race, with turbo huffing and puffing until, exhausted, the next one takes over and then the next one. Thus unlike other diesels, it doesn’t run out of puff at mid-range revs after an early surge. Instead, it has a low-end surge and a mid-range surge and then, when you expect it to fade, it just keeps surging forward.

It’s helped by the eight-speed transmission that’s just a flawless companion in light and easy work or hard, attacking work. It behaves just as well with the transmission in Sport, Sport+ or Manual modes, with the box shifting down just about when you’d want to do it yourself.

BMW suggests that much of its focus with this generation of X6 has been in ride and handling and there’s plenty of evidence of those efforts.

It’s somewhere between a tauter X5 and a heavy M550d xDrive. It gives you a choice of EcoPro, Comfort, Auto, Sport and Sport+ modes and you can fiddle around with them to set it up how you prefer. It gives its best performance in the Individual mode when you dial up all the powertrain, steering and skid-control modes to Sport but leave the suspension in the self-governing Auto mode.

Its handling envelope is astonishingly broad, especially when you figure out how to turn off the steering-weirding lane-departure system. And while the weight and relatively high roll centre dull any rewarding feedback, you can’t help but admire the way it moves.

The more enthusiastically you throw the X6 into corners, the more respect you have for what BMW has achieved.

It corners flat, with the boffins having eliminated the up-over-across feeling of the body weight moving over the back end during direction changes. The new X6 just points hard into one corner, the nose biting with unflappable arrogance, then whips back when the road bends the other way with the same unflappable arrogance.

It never quite moves with the lightness of touch to be entertaining but it’s damned impressive regardless.

Given that the X6 rides on largely the same core architecture as its predecessor (it even has the same 2933mm wheelbase), with the addition of electric power steering and freer wheel bearings, the improvements are astounding.

It’s not quite the same in its ride story, because unless it’s left in Comfort or Auto, it’s a bit too nibbly over small bumps and imperfections on its 19-inch tyres (255/50 up front and a chassis-tuning 285/45 at the back) otherwise.

Even so, it’s a comfortable place to spend time, regardless of whether you’re in the front or rear seats: even though it has 40:20:40 seating in the rear, there’s enough head and shoulder room in all three of its belted positions.

The automatic rear door hides 580 litres of luggage capacity (up 10 litres), but that balloons out to 1525 litres when the seats are folded flat, giving a 75-litre gain on the old car while remaining (gulp) 345 litres shy of the more-staid X5.

It’s more of the same playbook, then, as the last X6, but better executed. It has better handling, better performance, better ride, better fuel economy and it’s quieter at speed, too. And, like its predecessor, if you want BMW’s most practical SUV, you won’t come to the X6 badge. But if you want BMW’s best handling SUV and its least shy and retiring model of all, it’s the place to be.

And now its German premium rivals know what the category benchmark is.

What we liked:
>> Crunching engine performance
>> Mass-defying mid-corner grip
>> Easily accessible handling

Not so much:
>> Core architecture not new
>> Rationality isn’t its friend
>> Less practical and spacious than X5