Okay, so get this: We've been laughing at BMW for years because of its insistence on calling the X5 an SAV. That's Sports Activity Vehicle. It's funny because the X5 is, by anyone else's definition, an SUV. Sport Utility Vehicle.
Why "activity?" Sure, you can do a lot of "activities" in the X5. You can spin its little iDrive controller until the computer locks up (which is fun). You can play with its new-wave shifter (which is a little disturbing, because it's shaped like... well, grab one and you'll know). You can even drive the thing. That's one particular activity that the X5 is really, really good at.
But what's BMW's problem with "utility"? We think the X5 has a huge amount of utility - it seats 7 people, it can tow 6000 pounds, and it can even do some off-roading. That's all very useful stuff. So, sorry BMW, but the X5 is an SUV. And a good one. Deal with it.
The new X6 is based on the X5, but it's not an SUV, either. In fact, it's not even an SAV. It's an SAC - a Sports Activity Coupe. Oh, really? To me, a coupe has two doors (even if it's called a Mercedes-Benz CLS or Volkswagen Passat CC, by the way). I'm going to let the ridiculous name slide for once, because there's one huge truth in the X6's SAC designation: the word "sports."
The X6 is oh-my-God good in corners - to the point that it's downright disturbing. No SAC, no SAV, and certainly no SUV should ever, ever be this good in corners. Especially when it weighs as much as two E30-series M3 (1988-91) coupes. And speaking of M3s, BMW says the V-8 X6 laps Germany's Nürburgring Nordschleife in just over 8 minutes, 30 seconds - about ten seconds slower than the E46-series M3 (2001-2007). Yeah - that one, with a 333-hp 8000-rpm engine and a chassis to die for. That's just ridiculous.
The X6 comes in two trim levels. The $53,275 X6 xDrive35i (no, that's not a joke, that's its real name) comes with that delicious 300-hp, 300-lb-ft twin-turbo in-line six that we adore in the 135i, the 335i, and the 535i. Saddled with the X6's weight (4894 lb), the overachiever of an engine still manages a 6.5-second 0-to-60-mph time. In regular driving, the 3.0-liter's big midrange torque is helpful, but if you catch the engine off-boost, patience is required. Luckily, the two teensy turbos spool up very quickly, so lag is minimal, especially at high revs. But because the turbos are so small, the engine runs out of boost (and therefore power) over 6500 rpm. Sure, it happens in the other 35i-motored cars, too, but you don't notice it as much because you're too busy giggling at how fast you're going.
The X6 xDrive50i starts at $63,775 and has an all-new V-8 under the hood. At 4.4 liters, the engine is smaller than the 4.8-liter in the other 50i-engined cars (the 550i, 650i, and 750i, to name a few) and the X5 4.8i. In place of the displacement, it packs two small turbos in the valley of the engine block's vee, and consequently it makes even more power: 400 hp and 450 lb-ft of torque. (The normally aspirated 4.8-liter makes 350 hp and 350 lb-ft in the X5). I wish I could say that I like the V-8 as much as I love the 35i motor, but I don't. The engine's power - and its huge torque plateau - are nice, but it experiences a lot more lag than the six-cylinder does, even at high rpm. I'm not a fan of turbo engines because I like instant throttle response, so this V-8 and I got off to a rough start. And speaking of rough starts, I had a few with the V-8: giving a little gas when accelerating off the line results in nothing, nothing, and then way too much power as the turbos spool up.
In normal driving, I preferred both the sound and the responsiveness of the xDrive35i. Its shorter gear ratios mean it feels almost as quick around town as the V-8 (it's not, though-the xDrive50i rips to 60 mph in only 5.3 seconds, according to BMW). Moreover, the ZF 6-speed automatic transmission is so mind-blowingly adept at banging off seamless shifts that I'd rather beat on the slower X6 instead of using the V-8's torque to ooze around town.
The other big news in the X6's driveline is Dynamic Performance Control, an active rear differential that can shuffle engine power (or engine drag) between the two wheels. It works together with the standard xDrive all-wheel-drive system but works like a limited-slip rear differential on steroids. Where a limited-slip diff aims to lock the two axles together in response to a slippage on one side, the DPC differential can actively shuffle power back and forth between the two - no slip is necessary. More important, it doesn't just lock the wheels together, sending up to half the torque to each side; it proactively sends torque from one side to the other. DPC can engage full "lock" in only 400 milliseconds, and at that point, it can take up to 660 lb-ft of torque from one rear wheel and transfer it to the other. That's 1320 lb-ft of torque more on one side of the car than the other, which can be used to steer the X6.