The 2009 BMW X6 in the snow.

LeMansX5 · #1 01-24-2009, 11:39 AM

From Automobile mag:

The 2009 BMW X6 in the snow.

If you look closely at the picture, you’ll see something hideous. Something horrible. Something… abominable. Yes, kids, it’s the abominable snow van.

Looks aren’t everything, of course. And you may actually like the way the BMW X6 looks. I don’t. But there’s one thing we can’t disagree on: the X6’s ability to mask its 5300-lb weight and dance like a ballerina when things get slick.

I had the pleasure (and I do mean that) of spending a long evening with this particular X6 in below-zero (Fahrenheit) temperatures and on snow-covered roads. An xDrive50i model, it was outfitted with the twin-turbo, 400-hp 4.4-liter V-8 and, uh, summer performance tires.

So grip—whether braking, accelerating, or cornering—was near zero. Slight grades that presented no challenge to front-wheel drive sedans on all-season tires were, at best, a “maybe” proposition in the X6. Not the car’s fault—it should have been wearing winter rubber—but the lack of grip gave me the opportunity to really test the X6’s over-the-limit handling behavior at safe speeds.

And… Oh My God.

I thought the hours I had spent flogging the X6 in the dry—and on wet skidpads—were enough to know that its trick rear differential was amazing. And I was right, but in near-zero grip conditions, the system’s performance becomes mind-blowing. Poor executive editor Joe DeMatio, who thought he’d be winding down for bed after a few glasses of red wine over dinner. Instead, he listened to a half-hour of hyperactive physics babble from me.

The X6’s Dynamic Performance Control differential, if you’ll remember, can actively shuffle power between the rear wheels. Unlike a limited slip diff, which progressively locks the two wheels together (transferring, at most, half of the torque to each wheel), the X6’s differential can send all of the power to one side. Powering only one side of the car creates a moment that wants to pivot the car in one direction or the other.

Rather than just use the diff’s advantages to help put down power, BMW’s engineers have programmed the whole system to assist in turning the X6 (to reduce understeer) or resist turning (to reduce oversteer). The system works both when there’s power being put to the ground or engine drag trying to slow the vehicle.

BMW’s stability control system has a reduced-intervention mode called DTC that lets the X6 get a little sideways, and the mode best takes advantage of the diff’s magical ability to turn the car. Conventional stability control systems pull power (almost entirely) and forcibly brake one or more wheels to keep the car under control accelerating around turns in slippery conditions. The result is a disjointed, head-bobbing, and ultimately, very slow process.

The X6, on the other hand, just smoothly goes around the turn. Using the differential to help turn the car (as well as the active steering system), only occasional computer-initiated stabs of the brakes are necessary, and the engine’s power doesn’t need to be cut nearly as much.

I also had access to an Infiniti EX35 that evening, and I used it in back-to-back tests with the X6 on the same handling course I set up. The EX also uses a sophisticated all-wheel drive system that favors power to the rear. It’s a very good system, and thanks to a set of very grippy Blizzak snow tires, the EX felt like it was on dry pavement compared to the X6.

And yet, around my little course, with stability control switched on, the EX wasn’t anywhere near as quick as the X6. Not even close – in fact, the X6 made its way around the course almost twice as fast as the EX.

With my foot firmly planted on the foor, the EX’s stability control computers cut power completely any time I was turning, and allowed almost zero yaw. The tight sections were navigated at walking speed.

In DTC mode, the X6 used all of its sophisticated electronics to pivot around the corners, slightly sideways, and at a much higher rate of speed. It felt as it were defying physics—it had almost no grip, but could still turn in whatever direction I asked it to. (Turn the stability control system completely off, and the X6 remains commendably throttle-adjustable, but slightly less impressive.)

I can’t wait for the opportunity to drive an X6 in the snow with appropriate winter tires. Judging by its performance on summer tires, it’s probably the best-handling car in the world on snow. Maybe that’s why the abominable snow man is so frightening – it’s not just the way it looks; it’s scary because nothing can outrun it.

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X5rolls · #2 01-24-2009, 01:13 PM

Pretty impressive impression - I'd like to drive one on warm pavement, forget the snow.

JCL · #3 01-24-2009, 03:07 PM

Good read. Impressive performance.

I like the quote: "it’s the abominable snow van"

Ameritrades · #4 01-24-2009, 06:44 PM

Very Cool - BMW has always been outstanding in comforting the driver in all regards... now down to engineering the monster X6 in winter conditions on summer tread

I guess thats why we all gather in these forums - thanks for the read.
Apparently I stand as the minority in loving the lines of the X6

dmlgc · #5 02-04-2009, 02:36 PM

Quote:

Originally Posted by Ameritrades

Very Cool - BMW has always been outstanding in comforting the driver in all regards... now down to engineering the monster X6 in winter conditions on summer tread

I guess thats why we all gather in these forums - thanks for the read.
Apparently I stand as the minority in loving the lines of the X6

Guess I'm in the minority also, I like the lines (owned many bimmers back to a 73 bavaria) but then again I bought one so I'm not impartial. The one thing that keeps amazing me is that the X6 handles ridiculously well for a 5200 pound "4x4 thingy".

Ameritrades · #6 02-07-2009, 12:31 AM

[quote=dmlgc]Guess I'm in the minority also, I like the lines (owned many bimmers back to a 73 bavaria) quote]

Mine was a White '71 BMW 2002 - my first car - my first love. I had every color 2002 in the rainbow (Red, Orange, Black, Lime Green & light Blue). I'm gonna have to hunt some pics & scan them in.

Ameritrades · #7 02-07-2009, 04:08 PM

Test:
Some old shots of my BMW 2002's.

First Shot: 1975 BMW 2002 sporting some OEM BBS wheels off a 325is

Second Shot: A picture I took for an article I drafted back in the early 90's for the "Roundel" (the BMW car Club of America magazine) entitled "A family Affair" where I wrote how my love for the BMW's started & how I lured my brother & father into the sickness.