Both muscular and graceful
David Booth, National Post
This just isn't right. I'm jamming into Road Atlanta's infamous "gravity cavity" at more than 200 kilometres an hour, the entire car getting seriously "light" over the big hump that drops into Turn 10. First, the slight kink at the end of the back straight loads the outside tires and then, when the road drops out from under you, the car suddenly humps sideways. At 100 km/h, this kind of behaviour would be all lighthearted fun. At 230, it may still be a whole lot of fun, but there's a sense of drama not captured at more sensible speeds.
That sense of foreboding should be dramatically heightened since I'm not, in fact, driving a sports car typical of such race track shenanigans. The real reason the situation needs a massive amount of adjustment isn't that I'm slewing sideways at 230 km/h but that I'm slewing sideways at 230 km/h in a sport-utility vehicle. OK, so it's a sport activity vehicle because that is BMW's affectation for its faux roaders, but the appellation hardly alters the fact that I'm racing around in something with an SUV's profile and a centre of gravity somewhere around my ears.
Thankfully, the SAV I am flinging about with an almost devil-may-care attitude has been thoroughly massaged by BMW's M division. Indeed, without BMW's famed motor-sports division's ministrations, chances are the X6 I'm driving with such elan would have ended up off the race track, say in neighbouring North Carolina. The X6 M is the first offroader to ever receive BMW's "M" badge, a significant fact considering that, not so very long ago, the concept of a high-performance SUV-- sorry, SAV -- was pooh-poohed by the good folks at BMW.
The transformation to M missile is actually quite easy for BMW. For one thing, unlike the M5's V10, which is purpose-built, the X6 M's basic engine -- the twin-turbo V8--already exists in the more basic X6 xDrive50i. BMW massages the big 4.4-litre engine to a staggering 555-horsepower output by re-routing the turbocharger plumbing more efficaciously (both turbos are nestled in the vee between the cylinders where the intake manifold normally resides) and by having both banks of cylinders drive both turbochargers through a set of "headers" that would do any hot rodder proud. That BMW has also turned the turbo boost up to an astonishing 22 psi is both the reason for the crazed power numbers and proof that the company's basic 4.4L V8 is truly overbuilt.
Such techno gibberish may wow spinning propellor types like Yours Truly, but all that matters to the person behind the leather-clad steering wheel is that the twin-turbo V8 delivers its maximum 500 pound-feet of torque all the way from 1,500 rpm to an incredible 5,650 rpm. The sensation is of endless power and, indeed, when you stand on the loud pedal, the X6 M jumps ahead no matter what the rpm.
It might have jumped in even more dramatic fashion did it not weigh in at a portly 2,305 kilograms. Even though that translates into an almost gargantuan 5,080-pound curb weight, BMW still claims a zero-to-100-kilometres-an-hour time of 4.7 seconds, which is way deep into sports car territory. It's scary to imagine what this drivetrain might accomplish in a lighter chassis.
All that avoirdupois has seemingly little effect on the X6 M's handling as well. Oh, sure, the SAV might handle even better were it to shed a thousand kilos or so, but there is truly little to deride in the comportment department. Everyone returned from their maximum adrenaline lapping of Road Atlanta positively amazed at how well the big X6 M managed its high-speed foray. The brakes -- big, four-piston calipers up front -- faded but little, the variable-effort Servotronic steering had plenty of feel and, despite serious attempts at clipping apexes, there was precious little body roll. This last is made all the more amazing since the M's ride is as accommodating as the basic X6's.
Traction was impressive also as the X6 M's big 20-inch wheels wear sticky low-profile performance radials (P315/ 35R20 in the rear and P275/ 40R20 in the front). And even when enthusiasm does get the better of judgment, BMW's stability control system brings the big X6 back into line.
The rest of the M is very much standard X6 save for some optional trim bits such as the carbon fibre-patterned leather surrounding the centre console and inlayed throughout the doors. That means it's roomy in both rows of seats, has plenty of headroom fore and aft and there's a good-sized trunk, though you can't pack luggage as high as you can in an X5 because of that sloping roof. That so much of the basic X6 is carried over is one of the reasons the M's sticker price is an almost reasonable $99,900.
The only thing stopping a complete affirmation of the X6 M's prowess is the ever more resounding question of who really needs an SUV--OK, SAV -- with a coupe-like sloped roof, all-wheel drive and 555 hp that weighs only slightly less than an Escalade? It's a little like watching Serena Williams out-hustle the lithe twig-like figures that make up the rest of the female tennis world; I admire its triumph of enthusiasm over genetics and am amazed how something so muscular can at the same time be so graceful. Nonetheless, I can't help but think that both would be better served if they lost a few kg.