Driven: 2010 BMW X6M
By Tom Martin
July 08, 2009
What Was the Question, Again?
Let’s face it, the BMW X6 is an unusual car. We simply aren’t yet accustomed to a large, tall, fastback SUVs (or SAVs as BMW would have it). Making such a car in an M version makes it even more unusual, and challenges the cerebral cortex even more.
Separating idea from execution for a moment, we’ve argued in favor of a car that combines AWD, better than average ground clearance, luxury appointments, attractive design and good performance. If you like, we’re talking about an Evo for grownups, or a less utilitarian Audi AllRoad S. Such a car could be desirable in urban environments and for road trips that aren’t confined completely to perfect blacktop.
We think that’s something of what BMW had in mind for the X6 (you also have to remember that BMW is a niche company, so the X6 targets a niche within a niche). Making it an M car, except for brand purists, certainly doesn’t make it worse (for those who still don’t get it, there is also an X5M). And, of course, BMW didn’t just crank up the boost on the existing X6 and slap on some M badges. Real engineering was involved, some of which will see the light of day on future BMWs targeted at mainstream buyers.
The X6M engine is special. The twin-turbo V-8 delivers 555 horsepower. Even more essential for a car of this weight (just over 5100 pounds), the M motor offers 501 pound-feet of torque from 1500 to 5650 rpm. BMW has added something they call “cylinder block compressive exhaust manifold.” Besides the innovative routing of the exhaust to the top of the engine (which was done for the standard version that we get in the 750i, and the X5, and X6), BMW now spins each turbo with exhaust from both banks of the V-8. Because of timing differences in cylinder firing, this speeds up turbo response. I can verify after driving the 750Li last week and now this, that the X6M is noticeably more linear in power delivery.
The other big engineering project for a heavy AWD car is dealing with understeer. BMW addressed this with the X6 by adding Dynamic Performance Control to the xDrive system. DPC (love those acronyms, don’t you?) is an active differential that allows the outside rear wheel to get more torque and the inside wheel to get less or negative torque. All this is done via gearing and is controlled by computers. The system in the X6M simply allows more aggressive and balanced handling options through the all-important M button on the steering wheel.
We were at Road Atlanta to try all this stuff out. As with the Porsche Cayenne Turbo, the car works amazingly well, though it leaves you with the question “is it actually good, or just ‘good for an SUV’?” First, the good part. On a track, at least, the X6M has a nice balance of roll stiffness and compliance. The stiffness is good because the car doesn’t feel sloppy. The compliance is important because you can sense quite well what the car is doing, which builds confidence (and is fun).
The fancy diff and M mode also mean that the X6M rotates pretty well, with the tail feeling rather willing to come around. Steering (which is not active) is very usable, and the revised automatic gearbox shifts very quickly. Paddles are on offer, though we preferred the excellent console mounted lever.
All of the above is true up to about nine-tenths of the limit. When you really get going, the X6M retains its balance but only by asking quite a lot from the tires. Scrubbing and juddering are par for the course, which is okay as far as speed goes, but there’s no question that at-the-limit performance is a rather rough and tumble experience.
Another aspect of the X6 at speed is its power delivery. BMW quotes 4.6 seconds for the 0-60 sprint. That’s probably right, given AWD, but the X6M feels more like a low five-second car on the road. That’s very good, and power is strong—you simply can’t hide all that weight completely. The engine also makes very nice noises, with an especially well-judged exhaust note.
We’ll have more later, but at $89,875 plus options this is a very unusual, very niche, though very good car (for what it is). Still, we couldn't help but notice that the X6 M gives off the feeling that it was conceived before October, 2008 (which of course it was).