[14] Bmw X6 2009 Making This Week Talks

But the characters of the motors, and thus the respective driving experiences, are remarkably different. The Infiniti engines are large (either 3.5 or 5 liters), naturally aspirated and tuned to rev, while the BMW power plants are smaller (3 and 4.4 liters, respectively) and use twin turbochargers to deliver muscular low-end torque.

I didn’t drive an X6 with the V-8 (it doesn’t arrive at dealers until August), but even the 6 has the sort of effortless thrust you’d associate with a much larger engine. This twin-turbo 6 is such a smooth, delectable source of motivation that it could be used to power a dentist’s drill and you’d be happy to climb into that chair and pry open your mouth.

In the BMW, you don’t need to search out the redline to access the power; in the Infinitis, you’re encouraged to work the motors, and you’re rewarded with assertive exhaust notes and acceleration that’s more in line with sports sedans than S.U.V.’s. The V-6, in particular, encourages trips to the rev limiter with a snarling exhaust note that sounds like Daft Punk sampling a Husqvarna chain saw. And I mean that in a good way.

ImageThe X6 trades back-seat utility for a drastic sloping roofline and a two-plus-two seating layout.

Fuel economy was never a priority for a performance-oriented luxury wagon, but most iterations of the X6 and FX break 20 m.p.g. on the federal highway ratings. The rear-drive FX35 manages 23 m.p.g. on the highway, which might not bring OPEC to its knees but is at least a step in the right direction. The X6 with a V-8 is thirstiest, rated 13 m.p.g. in town and 18 on the highway.

Both the X6 and FX feature tech toys. The secret weapon in the BMW’s performance arsenal is a system called Dynamic Performance Control (DPC), which is essentially an advanced rear differential that uses electronically controlled clutches to shuffle torque to the outside rear wheel in corners. The effect of this trickery is that the rear tires help to steer the car, and the stability control system can get you out of trouble by redistributing power.

I’ll say it: in the real world, DPC comes in handy for cutting people off. If you’re turning left across traffic, you can really nail the throttle and count on the car to sling itself through the gap with no gut-wrenching stability-control stumble to interrupt your trajectory just as the grille of a Ford F-250 looms in your side window.