When BMW launched its X5 back in 1999, Munich's marketing mavens refused to categorize it as a sport/utility vehicle; instead, proclaiming its unibody, all-wheel-drive people-mover a Sports Activity Vehicle or SAV. Pretty tricky, eh? Well BMW is at it again, but this time it's gone even further -- behold, the 2009 BMW X6 Sports Activity Coupe, aka SAC.

It probably won't come as a surprise that the X6 borrows from the X5's chassis and electronics. As I outlined recently in my last blog, BMW builds the world's supply of Z4s, X5s and now X6s on the same line, at the same plant, in Spartanburg, South Carolina, although Z4 production is eventually moving to Germany. While previously thought to be starting its life as a 2009 model, BMW's official U.S. release and its consumer site refer to the X6 as a 2008.

A key difference between the SAV and the SAC can be traced to the X6's roofline, which BMW designer Adrian van Hooydonk claims is cribbed from the 6 Series. I say it looks more Z4-ish, especially with the slight upward tilt at the rear. Whatever DNA it borrows from, it's definitely striking. The roof peaks above the driver and front passenger before trailing back gracefully. Obscure the lower third of the X6, and it could easily pass as some hot new sport coupe. But once those muscular fenders and 20-inch rims come into view, it's clear this vehicle is something completely different.

The X6 will come in two flavors for the U.S. market initially (a hybrid is all but assured and a diesel option is a possibility). The entry-level X6 xDrive 35i is powered by BMW's fantastic and now familiar twin-turbocharged, 3.0-liter inline-six, massaged to make 300 horsepower and 300 lb-ft of torque. The X6 xDrive 50i -- its ballsier, bigger-engined brother -- features the first application of the automaker's all-new 4.4-liter twin turbo V-8 that pumps out 400 horsepower and an extra-stout 450 lb-ft of torque. Both engines are mated to BMW's standard six-speed, paddle-shift automatic transmission, and power is routed to all four wheels via xDrive, the automaker's proprietary all-wheel-drive system.

The X6 also serves as the debut vehicle for BMW's new torque-vectoring system called Dynamic Performance Control (DPC). I explained it in depth during my earlier drive of the prototype X6, but basically, DPC is akin to Honda's Super Handling-All Wheel Drive -- though there is a key difference. DPC uses a "mechantronic" system of two planetary gear sets, a multiplate clutch, and an electric helper motor to divide torque between the rear wheels. And, unlike Honda's system, BMW's works in both on- and- off throttle situations.