Under the Hood

Both engines incorporate direct fuel injection and turbocharging. The xDrive35i uses a new 3.0-liter inline-six-cylinder with one turbocharger, while the xDrive50i uses a 4.4-liter V-8 with two. Power ratings are unchanged on the new six-cylinder, but BMW says it is more efficient. BMW says both engines promise minimal turbo lag and a flat torque curve that begins under 2,000 rpm.

300-horsepower, 3.0-liter six-cylinder with 300 pounds-feet of torque (xDrive35i)
400-hp, 4.4-liter eight-cylinder with 450 pounds-feet of torque (xDrive50i)
New eight-speed automatic transmission
xDrive's Dynamic Performance Control doles out power from front to rear and side to side, at least among the rear wheels
Differential electronically varies power proactively from a full 50/50 lock to as much as 100 percent going to either wheel to enhance performance and safety
Adaptive Drive system electronically alters suspension's stiffness between sport- and comfort-oriented settings to suit different driving conditions

    See also:

    Driving tips
    This section provides you with information useful in dealing with specific driving and operating conditions. ...

    Reference
    This chapter contains technical data, short commands for the voice activation system, and an index that will quickly take you to the information you need. ...

    Switching off automatically
    System switches off: above approx. 9 mph/ 15 km/h. Switch on the system again if necessary. ...