2008 BMW X6 xDrive 35i

Lost among the twin-turbocharged whoosh of the X6 xDrive 50i launch was the fact that BMW also dropped an entry-level Sports Activity Coupe as well, the 2008 BMW X6 xDrive 35i (heretofore regarded as the 35i; trademark lawyers be damned!).

Minor exterior details separate the 35i from its bigger brother. Up front, the grille is black instead of brushed aluminum. The turn signals blink in red on the 35i; amber on the 50i. Twin, circular exhaust tips signify the 35i's twin turbo, 3.0-liter inline-six, while the 50i gets a pair of trapezoidal tips.

The drive is what really separates the two, however. I drove an X6 35i and 50i back to back at Michelin's Laurens Proving Grounds. Both were shod with identical sets of Dunlop Sport Max tires, 275/40R20 up front and a whopping 315/35R20 at the rear. While 19-inch wheels come standard on both, they look comically small. You really need those fat 20s, especially in the rear, to make this bulldog look right.

On the wet track, I was surprised to find the 35i to be the rougher-riding, less stable of the two. Forget the slick surface performance, which was excellent by the way. I was more curious as to why the 35i seemed to transmit more of the bobbles and bumps of the roadway. The answer came from one of the driving dynamics engineers, who revealed that the 35i was roughly 280 pounds lighter in the front due to the smaller engine.

This weight difference produced another characteristic on the dry track -- much dartier handling. Both X6s feel agile for their size and weight, but the 35i feels lighter on its toes, more nimble, and generally happier to move about -- as if it had a 280-pound colonic, I suppose.

Of course, when it comes to a drag race, the 50i takes the pinks, the Wally, and three umbrella girls home. The 35i's 300-horsepower engine is as sweet as turbo sixes come, but is no match to the 50i's 400 horses and 450 lb-ft of torque.

Still, if you ask the question: "Will the real Sports Activity Coupe please stand up?" I have to say that the 35i better fits the letter and spirit of the concept. While the 50i has that freight-train stability and rush of acceleration, it can feel heavy and planted at times -- particularly when you slam on the massive 385 millimeter brakes. The 35i has less of that feel; it darts around with a lightness and ease. It's not a stretch to say there's some sport coupe DNA in the way it drives.

Stick with us as we bring you more information, updates, and quite possibly the first test of the new X6 against a surprise rival.