Initially, the BMW X6 was available in North America (Now released in the UK) in two variants. Both use twin-turbocharged engines. The top-of-the-line model is the xDrive50i which uses an all-new 4.4-liter twin-turbocharged V8 engine. It produces 408metric horsepower (300kW) between 5,500 and 6,400 rpm, and 600 N·m (443 ft·lbf) of torque over a wide range of between 1,800 and 4,500 rpm. It is the first production turbocharged V8 engine in the world to feature its turbochargers between the V section in the middle of the two banks of cylinders.
The other model is the X6 xDrive35i powered by the N54 3.0-liter twin-turbocharged inline-six gasoline engine, producing 306metric horsepower (225kW) between 5,800 and 6,250 rpm, and a peak torque of 400 N·m (295 ft·lbf) between 1,400 and 5,000 rpm. This engine also sees duty in the 1, 3 and 5 Series BMW cars.
Two diesel variants have been announced, and are expected to constitute as much as 90% of sales volume in European markets. The models are called the xDrive30d and xDrive 35d, respectively. They are powered by BMW's 3.0-liter turbodiesel engine (in its sequential twin-turbocharged variant for the xDrive35d), and produce 235PS (173kW) in the xDrive30d and 286PS (210kW) in the xDrive 35d version. The second of these power units will form the basis of BMW's Diesel launch in all 50 states in late-2008.
Dynamic Performance Control
The X6 marks BMW's first use of its new Dynamic Performance Control system, which works in unison with xDrive all-wheel drive (both are standard on the X6). DPC is a drivetrain and chassis control system that works to regulate traction and especially correct over- and understeer by actively spreading out drive forces across the rear axle. Torque is split not only between the front and rear wheels (xDrive) but also from side to side at the rear for improved agility and added stability (through the DPC rear axle).