Let’s start by congratulating BMW for bringing its first batch of hybrids to market (the 7 Series ActiveHybrid is launching alongside the X6). In everyday traffic, the hybrid system helps keep fuel consumption down – to a still-lame 18 mpg combined (estimated) – and, since the engine can shut down at stops, the ultra-quiet interior made sitting in Miami traffic during our preview drive almost a pleasure. Nevertheless, there’s still a lot of vehicle here that hampers any attempt at real fuel efficiency gains. The X6 ActiveHybrid weighs 5,688 pounds for crying out loud – 400 pounds more than the non-hybrid. This vehicle simply doesn’t makes a lot of sense for anyone actually interested in fuel efficiency.
The ActiveHybrid powertrain in the X6 is a complex animal, being that it’s made up of a twin-turbo 4.4-liter V8 engine, two electric motors (one that puts out 91 hp and a smaller brother that manages 86 hp), three planetary gearsets and a 2.4 kWh NiMH battery pack. All that machinery manages to produce 357 kW (485 horsepower) and 780 Nm (575 pound-feet) of torque. This is what BMW has created out of the two-mode hybrid system that the Bavarians co-developed with General Motors and Mercedes (think Chevrolet Tahoe Hybrid and Benz S400 Hybrid). BMW claims its hybrid SUV can achieve fuel efficiency of up to 9.9 l/100 km (about 24 mpg U.S.) on the European drive cycle, but during our a few hours in the 2010 BMW X6 ActiveHybrid Sports Activity Coupe, we averaged just 14.8 liters (16 mpg U.S.).
bmw x6 concept car
bmw x6 concept carOn the way to 16 mpg, the X6 ActiveHybrid performs like one expects a BMW to. It wasn’t possible to test the handling much on the straight and clogged streets of southern Florida, but the CUV had plenty of punch for entering highways – the 0-to-60 mph time is a quick 5.4 seconds – and keeping up with traffic was a doddle. Power, be it electric or gasoline-fueled, was readily available whenever we touched the accelerator pedal. As much as the drivetrain offered, we didn’t get anywhere near the vehicle’s electronically limited top speed of 130 mph due to traffic. The good news is that there’s no need to go fast to enjoy the drive: at any speed, the X6 offers a comfortable cruise, with bumps and other annoyances passed over with ease. Also, the X6 ActiveHybrid’s electrical steering feels about as good as any hydraulic system ever has - at least in these non-challenging circumstances.
For all the work that BMW engineers did to make the X6 ActiveHybrid burn less fuel, they haven’t chosen to apply some of those same easy tricks across the X6 lineup. For proof, take a look at those special aerodynamic wheels that are available only on the gasoline-electric version of the X6. While they do reduce emissions by 0.1 grams of CO2 per kilometer, don’t try to order them for your standard X6. The reason? BMW wants to give its first hybrid in the U.S. a distinctive look and those special wheels are one way the driver can make a statement. All is not lost, though, and BMW told us that making the aero wheels an option on the standard X6 is “in discussion.”
2010 bmw x6
2010 bmw x6Of course, the real efficiency gains come from the battery, not the wheels. The liquid-cooled 2.4 kWh NiMH battery pack sits between and above the rear wheels, offering the powertrain 1.4 kWh of its total power. The part-electric set-up gives the X6 four operating modes: eDrive, eBoost, Charge and Drive. eDrive is the most efficient and uses nothing but electrons to attain up to 37 mph for up to 1.6 miles. It’s not a plug-in hybrid electric vehicle (PHEV), but it works great in parking lots and during stop-and-go traffic like we experienced in Miami. eDrive doesn’t help drivers who like to engage the manual shifter, however, as it’s available only when the transmission is in D, not in manual shift mode. eBoost, on the other hand, uses the two electric motors to boost the internal combustion engine’s performance when needed and is the reason this beast never feels sluggish. ‘Charge’ mode means the regenerative brakes are capturing energy that would normally be lost from the discs, and finally, ‘Drive’ just means the X6 is using nothing but the V8 to move forward.
The good news is that the complicated transmission of power goes completely unnoticed, showing that BMW’s engineers have done a tremendous job of blending the vehicle’s electric and gasoline-fed powerplants. Shifts are wonderfully smooth and the switch from electric to hybrid to pure gasoline drive just happens. You can hear the changes if you pay close attention – and there is an analog display under the speedometer showing the battery’s state of charge and whether or not it is charging up – but the best way to tell what is happening under the hood is to have the drive mode displayed on the iDrive’s info screen.
2010 bmw x6 pictures
2010 bmw x6 picturesEven though there are two different brake systems on the X6 ActiveHybrid, don’t look to the brake pedal to reveal which is engaging. The brake pedal is decoupled from the actual brake system and uses simulated feedback to tell the driver what is happening. Most of the time (up to 0.3 Gs), only the electric motors are used to brake the X6 ActiveHybrid. In other situations (read: emergency or sudden stop), the standard friction brakes kick in. The decoupled simulation is meant to make sure the driver experiences the same feeling at all times, and it easily passes for the real thing. Because the regenerative brake system in the X6 uses both electric motors, it is able to capture about 25 times more energy than the company’s other regen systems. This isn’t as big a deal as it sounds, since BMW’s Brake Energy Regeneration is fairly wimpy. The two 60 kW motors are theoretically capable of capturing up to 120 kW of energy, but the battery can only handle 57 kW.
The X6’s design has its fans and detractors, but the Kammback shape does help the X6 stand out – for now. We can deal with the hood hump – excuse us, PowerDome – and the tall rear end most of the time, but from inside, the design is troubling. Backing-up is terrible, and the rearview mirror only serves to make the back of the car look like it’s a million miles away. Luckily, BMW has installed an almost-magical back-up camera system, which, like Infiniti’s Around View Monitor, uses cameras built into the rear end and under the side mirrors of the X6. When driving backwards, an image appears on the navigation screen that looks like a camera is floating above the car and showing the close surroundings. Using this screen and the curved side mirrors, it’s possible to back out of a garage or parking spot safely. Trying to do so just by turning your head? Not so much.
While we’re still waiting for the EPA’s official figures, BMW expects the X6 ActiveHybrid will to achieve 17 mpg in the city, 19 on the highway and 18 combined. That’s better (except on the highway) than what the best non-hybrid X6 can muster: 15/21/17 for the 2010 X6 xDrive35i. A better comparison for the X6 ActiveHybrid is to the X6 xDrive50i, which also has a V8 engine and gets 13/18/15. The X6 ActiveHybrid goes on sale in the U.S. next month and will be built in Spartanburg, South Carolina. The starting price is $89,775 (including an $875 destination and delivery charge), which would make it even more expensive than the 555-hp X6 M.
In the end, we’re not sure who will want the X6 ActiveHybrid. Most likely they’ll be people who own an aging BMW X5 and want something new with more power and no penalty at the pump (at least compared to the rest of the X6 lineup). If past popularity of big BMWs is any indication, there is certainly a market for the X6 ActiveHybrid. Today, about 20 percent of BMW sales are X models. Introduced in 1999, the X5 was the brand’s first SUV and remains the most popular, with 911,000 sales. The X3 has sold 554,000 and the X6, introduced just last year, has already sold 57,000 units.
We need more time with this big hybrid crossover to be sure, but based on our short drive, the BMW X6 ActiveHybrid will probably not find itself on our shopping list. All that extra hardware (and weight) and what we expect will be the highest price of any X6 model is balanced only by a marginal gain in MPGs. For us, although it’s a laudable technological achievement, the value just doesn’t add up.
Curious car, this one. Despite a massive temptation to ask just how such a thing ever made it past the idea stage, car companies, particularly German ones, don't tend to make things that they haven't already established someone will probably buy. Which means that, when asked by the researcher with the clipboard and fixed smile, more than one person must have said "Yes, actually, there is an X6 M shaped hole in my life". Who these people are and what sort of lives they lead is anyone's guess but, having driven the X6 M, I can only suggest that they are conflicted. Very conflicted.
Because the car is, too. Quite apart from the fact that BMW's M division a few years ago swore that they would never use 4WD, a turbocharger or an automatic gearbox, and the X6 M features all three, there's also the glaring issue of, what the hell is it for? I spent most of a day thrashing the bejesus out of one at Road Atlanta racetrack trying to find out and ran the thing out of petrol before I could come up with a convincing answer.
It's not that it wasn't fun on the track, it was. It monstered its way around the circuit, consuming kerbs and curves, hitting almost 150mph down the long back straight and stopping straight and true, lap after lap. It was more the constant nagging that it was all a bit ridiculous and that a car with half the weight and half the power - such as the original M3 - would have been more entertaining and less complicated to explain.
Whatever. The first thing you need to know is that the X6 M is as fast as the current V10 M5 in a straight line. That's very fast. Both do 0-62mph in 4.7secs and run on to limited top speeds of 155mph. The second thing you need to know is that the X6 M does a similar lap time (8mins 30secs) to an E46 M3 - the one before the current one - round the Nerdbirdthing. And that's just absurd. Because going fast in a straight line isn't that hard with plenty of power. Going fast around a circuit is.
The reason for the X6 M's super saloon speed is simple in a very technically and typically complicated BMW way. I'll simplify: they take the stock 4.4-litre V8 motor, drop a pair of twin-scroll turbochargers into the V, bolt on a couple of intercoolers and, voilà, another 155bhp is born. This brings the maximum available power under your right foot to a round 555bhp and torque to an equally neat 500lb ft. But as nice as that is, it's not the clever bit. To ensure the power doesn't arrive in one almighty tyre-shredding peak, there is a new-fangled exhaust manifold that links cylinders on opposite sides of the engine. This ensures the blowers are constantly kept spinning smoothly and allows you to control your speed precisely.
This new pipework completely strangles the V8 sound, which is disappointing, but otherwise, so far so good. The reason for the X6 M's handling abilities takes a little bit more explaining. Building on all the clever chassis technology already fitted to all X6s, the M dept has thrown every single electric toy you can imagine into the mix. So, on top of the xDrive 4WD system and the M-tuned Dynamic Performance Control (DPC), which distributes power to each wheel based on things like available grip, direction of travel, etc, there's also MDM.
MDM stands for M Dynamic Mode. This allows you to create a maximum death setting for the chassis and drivetrain. And it's brilliant.
When you are feeling a bit tasty, you just press the M button on the wheel and the car changes immediately from a quick truck into an angry attack vehicle. On congested British roads where it's ‘go now or stay behind the caravan for another 50 miles', with MDM you will always go now.
And thanks to some spectacularly massive brakes - 15.6 inches at the front, 15.2 inches at the rear - you can always stop pretty much immediately when you need to, too. Even after six laps of racetrack abuse, the pedal did get a bit softer but never failed to stand the two-tonne plus X6 M on its nose. So no complaints there.
Likewise, the chassis, however complicated it might be, is pretty amazing. Ignoring the fact that the company created the problem they now claim to have solved, the X6 M is still very easy to drive very fast. Unlike the Porsche Cayenne Turbo S or GTS, in which you can feel all the electrical systems heaving and straining to keep the car heading where you want, the BMW feels comparatively mechanical. It still gets understeery if you take your eye off the ball or get into a corner too fast - two tonnes is still two tonnes however many systems you have -- but it's still miles faster through the curves than any other SUV-type vehicle, other than the mechanically identical X5 M.
Ah, yes, the X5 M. It's hard enough to make a case for the X6 M on its own, but against the slightly cheaper, bigger capacity, four-door X5 M it's nigh-on impossible. So it all has to come down to taste and character, or maybe lack thereof. And that's when it starts to make sense. Perhaps the X6 M is not for us Brits at all. Perhaps it's for other countries like the US and the Far East. Places where just being different is enough to make it desirable. Maybe that M on the X6 is not about motorsport so much as marketing. Look at it like that and perhaps the X6 M is not so curious after all.
No comments:
Post a Comment