Carz Arena

Barreling around the racetrack, there's little lean entering the corners, plenty of thrust on exit and a monster amount of grip everywhere, and if it feels taxed at all, it's ever so briefly as the nose aims left and up from turn five for the steep climb out of the esses.

Road Atlanta is plain ol' fast, and the BMW X6 M does well to keep pace, spilling gobs of power all over the track, blazing down the long back straight to nearly 140 mph, maneuvering like no two-and-half-ton pile of metal should. It's exhilarating stuff, to be sure, only we're left asking very many questions, and all of them are: Why?

Why would BMW make an all-wheel-drive M vehicle? Or an automatic M? Or an M ute at all?

Truth be told, the regular X6 makes little sense. It's a sport-ute (regardless of BMW's insistence on calling it a “sport activity vehicle”) with most of what makes the breed useful--that is, cargo hauling--lopped off in the name of coupelike styling while keeping the penalties intact, namely, a high center of gravity and lots and lots of mass. Stuffing it full of 555 hp, offering a bevy of performance-enhancing electronics and slapping a big M badge on its sloping butt makes it a heckuva lot of fun, but it's still a quirky vehicle with little compelling argument for its existence except that it's, well, compelling.

And for some enthusiasts, that's all that matters, which, we suppose, answers all those whys.

The magic for turning its 5,247 pounds into a road-going rocket is the specially tuned M engine, based largely on the 407-hp, twin-turbo 4.4-liter V8 found in the X6 xDrive 50i and the 750i. BMW swapped out the regular turbochargers on the base 4.4-liter for a pair of high-efficiency twin-scroll units, which themselves feed off a unique exhaust manifold that shuttles the outflow from paired but opposing cylinders to each scroll. This ensures a delivery of almost constant exhaust pressure to each turbo-charger, making throttle response almost immediate and turbo lag virtually undetectable.
A view from the back of the 2010 BMW X6 M.
A picture of A view from the back of the 2010 BMW X6 M.
BMW



A view from the back of the 2010 BMW X6 M.

Torque pours out in piles wherever you ask for it, too, and in any of its six gears, a full 500 lb-ft is on hand from 1,500 rpm to 5,650 rpm, which helps propel the X6 M to 60 mph from a standstill in about 4.5 seconds. Throw in some curves, and the X6 M feels nearly as fast and just as stable, partly because of BMW's active roll-stabilization system, which locks up the antiroll bars in response to body lean.

Although we'd prefer some version of a dual-clutch box over the automatic, the six-speed transmission, largely a carryover unit from the regular X6, does bang out the shifts in quick fashion, either left in full auto mode or when accessed via a pair of big paddles mounted behind the steering wheel.

Stopping duty falls to a giant set of brakes, four-piston calipers squeezing 15.6-inchers up front with single-pot rears on 15.2-inch discs. Like the tranny, the suspension makes its way from the standard X6 largely intact; its double-wishbone front and multilink rear get stiffer springs and dampers, while the whole body sits a half-inch lower. Still, even with its standard 20-inch wheels and run-flats, there's enough space in the wheel wells that the X6 M looks as if it could stand to drop another couple of inches. At least.

The only visual giveaways that this X6 gets the M treatment, beyond the badging,

are those larger wheels, vents just behind the front

fenders, bigger air intakes up front and four tailpipes peeking out back. All told, the X6 M will run you $90,550. That quirky styling comes at no extra charge.

2010 BMW X6 M

ON SALE: Fall

BASE PRICE: $90,550

DRIVETRAIN: 4.4-liter, 555-hp, 500-lb-ft twin-turbocharged V8; AWD, six-speed automatic

CURB WEIGHT: 5,247 lb

0-60 MPH: 4.5 sec (est)

FUEL ECONOMY (EPA): 17 mpg (est)