The question of could versus should...
I can’t remember the last time I heard anyone ask for a 555-hp SUV-or, an M version of their truck. We can get into endless discussions about whether M should be building such a vehicle (which, of course, I had with the brass at M) but there’s one thing that’s not up for discussion: there’s a new king in the performance SUV category.
A screw-up by BMW’s German PR department has given me exactly one hour and fifty-eight minutes to write my driving impressions on the X6 M before the embargo lifts. That’s not nearly enough time to collect my thoughts and write a coherent story, much less wade through the 25 pages of technical information we were just handed. So you’ll have to wait a few days for the full story. But there’s no reason you should have to wait for the unfiltered, raw information. Here I go:
The X6 M will cost $89,725; the X5 M (which we didn’t drive, but which shares all powertrain components) will be slightly cheaper, at $86,225. Under the hood is an M-massaged version of the 4.4-liter twin-turbo V-8 that made its first appearance in the X6 xDrive50i and also does duty in the 7-series sedan.
Massaged is a loose term. The engine, code S63B44, uses a brilliant-and patented-exhaust manifold and dual twin-scroll turbochargers to reduce turbo lag to levels previously unheard of. Coupled with an automatic transmission, the lag rounds to zero. It’s there, of course, but this is probably the least laggy turbocharged gas engine in the world. I expect nothing less from M-a company that has gone through the outrageous expense of installing independent throttle bodies on each cylinder of every normally aspirated engine it developed. (Those multiple throttles shave milliseconds from response time-turbos can sometimes add multiple *seconds* of lag.)
Output is quoted at 555 hp, with a perfectly flat plateau of torque (500 lb-ft) from 1500 rpm to 5650 rpm. The engine revs to 7000, though by that point it’s lost quite a bit of its thrust. The transmission is a special version of the brilliant ZF-developed 6HP26 6-speed automatic, which gains an “S” suffix. S obviously stands for “Oh My God,” because shift times are reduced to something resembling a dual-clutch gearbox. According to an engineer, shifts in manual mode are accomplished with the torque converter locked, and the entire shift takes place within the time needed for one single, solitary power stroke. The computers simply misfire one cylinder on purpose for an incomprehensively short interruption in torque, and by the time the next cylinder fires (one four-hundreth of a second later if the engine is at 6000 rpm), full power is given back. Shifts in automatic mode are also very quick-though not quite as fast, and are much smoother.
BMW claims that the 5300-plus lb SUV will accelerate to 60 mph in 4.5 seconds, and there’s no doubt in my mind that it will. In fact, if my butt is calibrated correctly, you can expect to see numbers even quicker than that from magazines that measure 0-60 mph times without rollout.
Both the X5 M and the X6 M use the amazing rear Dynamic Performance Control differential first seen in the regular X6. The electronically controlled diff can transfer up to 1300 lb-ft of torque from one rear wheel to the other, helping turn the car to follow the driver’s desired path. The X6 M put all of its power down without any drama whatsoever. The only time we saw wheelspin was during mid-corner slides after bouncing off curbing at the Road Atlanta racetrack, where we put the X6 M through its paces.
On the track, the heavy X6 M can’t be compared to other M cars-it understeers resolutely (though the torque-vectoring diff turns the car almost perfectly neutral under power) on dry pavement, and the rollover-mitigation portion of Dynamic Stability Control will put a quick end to very quick transitions despite the X6′s impressive body roll control. The X6 doesn’t serve up much steering feedback, and brake feel was far less progressive than we’re accustomed to in other BMWs. But it’s fast as hell in straights, in curves, and in braking zones.
Other than a few M touches on the instrument panel, the interior of the M is standard-issue X6, which means no special, extrasupportive seats, and no small Alcantara steering wheel. Still, the standard sport seats do a fine job of holding you in place while circling a track at speeds most sports cars would have a hard time bettering. The X6M and X5M don’t include much in the way of bespoke sheetmetal or chassis components, either. But like every M, the X6 is a holistic approach where the engine’s power matches the chassis’ ability to cope with it.
Unlike any other M ever, these two new vehicles use four-wheel drive, an automatic transmission, and each weigh as much as a small fishing village. And this is the first M engine to abandon M’s trademark high-revving concept in favor of forced induction. But as turbo motors go, the engine is as good as it gets, the transmission is the best automatic around, and the handling is as balanced and neutral as the world has ever seen in this weight and height category. It may be abandoning all of its own self-professed philosophies, but at least M nailed this awkward ball out of the park. Sick and tired of watching loyal customers buy Porsche Cayenne Turbos, these two SUVs make a great business case as low-volume, high-profit models. You may not like the direction that these trucks point toward-and I don’t, personally-but BMW, like any company, is in business to make money, not to please purist nutjobs like me. Now let’s hope M takes the sacks of cash it earns with these vehicles and gives us a lightweight, visceral, and raw sports car to finally compete with the Boxster and Cayman. 125tii, anyone?