BMW X6 ActiveHybrid 2009 Review - International

BMW X6 ActiveHybrid

Not so much
>> Ferociously heavy
>> Horribly expensive
>> No right-hand drive (again)

Overall rating: 3.5/5.0
Engine/Drivetrain/Chassis: 5.0/5.0
Price, Packaging and Practicality: 2.0/5.0
Safety: 4.5/5.0
Behind the wheel: 4.0/5.0
X-factor: 3.5/5.0

About our ratings

On BMW's own figures, it will take a million kilometers before the fuel savings from the new, X6 ActiveHybrid SUV will have paid back its staggering purchase price.

Combining two electric motors and a nickel-metal-hydride battery and a turbocharged V8 petrol engine might boost the fuel economy (marginally) and performance, but it also boosts the ActiveHybrid's German sticker price from the €76,000 of the standard X6 V8 to an astonishing €102,000.

At European fuel prices, that €26,000 difference represents 20,000 litres of fuel. Or a MINI Cooper S. That's almost $42,000 in Australia, so the big BMW would have to have to work harder, for longer at our cheaper fuel prices to get back to square.

But it's not coming to Australia, because BMW will only ever build the X6 ActiveHybrid in left-hand drive. While it's a wonderful drive, has an elegantly composed ride and, fabulous damping and turbine-surge acceleration, on balance, you'd have to think its absence from our roads will not be sharply felt.

Lexus has been edging down this road for years, but BMW's new X6 EfficientHybrid turns a sneaking suspicion into an unashamed reality: petrol-electric hybrids have now moved beyond the nerdy world of fuel-economy enthusiasts and into straight-out performance.

While it used its Vision EfficientDynamics concept car to hint that its performance future lay in electric motors adding punch at low revs, this is not a sports car. The X6 EfficientHybrid is a 2.4-tonne city cruiser, based off a machine roundly criticised for its profligacy but respected for its abilities.

With a combination of two electric motors, a turbocharged V8 engine, a very clever gearbox and a big battery, BMW has found an incredibly complicated way to hurl its X6 SUV to 100km/h in just 5.6 seconds -- and still claim environmental credit points because it claims 9.9L/100km, 231 grams of CO2/km, a 20-percent "theoretical" advantage over a similarly-powered petrol car and it's got the word "Hybrid" stuck on the back.

And yet, the standard V8 turbo X6 is 0.2ses quicker to 100km/h, weighs 250kg less, is far-less complicated and is a house deposit cheaper. Hmmm.

Even if logic would seem to limit its audience (and, thankfully, Australians don't need to make the choice), the X6 ActiveHybrid has been very well developed and is, in fact, an impressive machine.

It's the most powerful hybrid in the world, with a combined output of 357kW of power and 780Nm of torque, but BMW boasts it can still be driven on full electric power. And it can. Sort of.

Based around a system originally developed by General Motors, the X6 ActiveHybrid's drive system has been the subject of a joint development by GM, Chrysler, Mercedes-Benz and BMW. Indeed, the entire gearbox unit, complete with the two electric motors, is delivered straight from Mercedes.

Yet for the sake of expedience, it uses an old-school NiMH battery, not the generation-next lithium-ion battery of the 7-Series Hybrid (which also shares its tech with Benz).

That means while the X6 ActiveHybrid can run on its battery alone, it can only do it for a maximum of 2km and it can only do it up to 60km/h, and only if you use very, very light throttle openings. For all practical purposes, its full-electric drive status is token.

Yet, for all the complexity, it's not at all complex to drive. You just put the key in the ignition, push the start button and go. Even though there's no noise, the X6 is ready to play, which you figure out when you pull Drive and it just eases silently forward into the traffic.

That means it's running on one of its electric motors, which it continues to do until you ask for more speed or it drains the battery. Normally, from around 15 per cent of full throttle, the second electric motor will act to crank up the TwinPower V8, then turns itself into a generator.

Go quicker and the X6 is mostly driven by the petrol engine. Go quicker again, especially in acceleration from low speeds, and it's all engines to battle stations.
Good for economy? Umm, no.

While BMW posts 9.9L/100km on the official tests, we managed more than 24 on normal driving with the traffic in Miami, Florida and, on another drive, only 16 when we tried very hard to post good numbers. Real-world economy, then, isn't really its thing.

Luckily, there are other modes that aren't tokens, including the one where it recharges everything on braking or on overrun.

But it's the full-throttle punch that's impressive. Where other versions of this system are, essentially, like CVTs in operation, this one feels different because it has three planetary gears and four clutch sets stuffed into the gearbox to give it a more "normal" feel, with seven speeds and gearshifts where you'd expect them. Except on full acceleration.

Step on the throttle and the X6 ActiveHybrid leaps away like a bullet and keeps accelerating and accelerating like you're riding an enormous rubber band. It doesn't change gear at all, surging to 100km/h and beyond in a one mighty burst.

It takes a lot of energy to shift 2.4 tonnes with this alacrity and that's exactly what it can muster. If the battery is fully charged, it can bring the petrol engine's 300kW to bear, plus a 67kW electric motor and a 63kW electric motor.

(And, before you write in that they add up to 430kW, they don't. The limiting factor is the battery's ability to deliver enough energy to drive the electric motors at their maximum so, by the time the petrol engine is giving its best, the electric motors are past theirs.)

The 2.4kW/hr NiMH battery might not have the gee-whiz factor or the range of LI, but the energy regeneration ability of the X6 is 25 times more efficient than on any other BMW to date. Come off the accelerator or start braking and it can use both electric motors to generate up to 50kW of power, which the big brain can convert into electricity for easy re-use.

The trouble with most of these systems is that their regeneration setups make the brakes feel, well, awful. The Benz S400 Hybrid feels like you have a tennis ball underfoot and the 7-Series version of the same system is even worse. That's because most people give the brakes a soft brush a lot of the time and the boffins worked out they could provide that braking feel by simply wicking up electric motors to full resistance for a better recharge.

Fortunately, that's better in the X6, but it's not perfect. In fact, it's about the only thing about the driving experience that feels remotely remote.

For the rest, you can thank a very clever electric brain that also converts the high-energy direct current from the battery into the alternating current the electric motors prefer, and also figures out how much, when and where to use each motor. And does it superbly.

It switches in an out of electric drive to petrol drive impeccably and smoothly, with enormous refinement on offer and there is always performance for the taking, instantly, with the electric motors punching in torque from the millisecond they're thrown into battle.

It rides beautifully, too, and the handling is now incredibly composed for a car of this mass. And the cabin adds an electric map of where the drive is coming from and going to.

For all that (and for what it means for future BMWs), the only thing the X6 ActiveHybrid really adds to the X6 world (much less the motoring world) today is techno-geek cred and crunching acceleration away from the traffic lights.

If it's straight-line speed and handling you want, the standard petrol X6 does it better and weighs a lot less. And if it's economy you want from your X6, just get the diesel.

Because for all the effort BMW has clearly invested in it, the X6 ActiveHybrid just doesn't do anything special enough to justify asking €26,000 more for it.

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