transportation, business, shopping and ownership concept - customer and salesman shaking hands outside
(Dec 17, 2009)
The BMW ActiveHybrid X6 is about green power – and plenty of it.
It is billed as the "most powerful hybrid" in the world and with a combined 480 hp and 585 lb/ft of torque and a 0-100 km/h acceleration time of 5.6 seconds, there's little to doubt the claim.
But wait a minute!
Aren't hybrids supposed to be about little lozenge-shaped sedans or CUVs that proclaim, "I'm saving the planet"?
Actually, I am seeing more new luxury vehicles with hybrid technology than small cars. First, any new technology is expensive and luxury buyers are more willing to spend the money. And, second, there is no rule that says hybrids have to be piddlers.
So in a way, owners of vehicles like the ActiveHybrid X6 are helping everyone. Like big screen LCD TVs, as more are sold, the prices go down. Remember when the first digital watch, the Pulsar, sold for $350? Now you can get one for $20.
Based on the X6 Sports Activity Coupe and its 400 hp, twin turbo 4.4-litre V8, the Hybrid adds two synchronous electric motors (91 hp and 86 hp respectively) and a 57 kW nickel-metal hydride battery pack placed below the cargo floor. The battery has its own cooling system.
The introduction of BMW's ActiveHybrid technology in the X6 marks the latest BMW development of hybrid technologies. BMW started work on electric drivetrain research with the BMW E1 in the late 1980s.
This latest system allows the X6 Hybrid to operate at high or low speeds utilizing the two motors connected to one another by three planetary gear sets with a fixed-transmission ratio gearbox routing power to BMW's xDrive all-wheel-drive system.
The result is a reduction in fuel consumption by up to 20 per cent compared with a comparable BMW running on a gasoline engine alone. For instance, fuel consumption on the European combined loop is 9.9L/100 km.
For those of you interested in how it works (or you can skip the next six paragraphs), the two-mode active transmission is based on an ECVT (Electrical Continuously Variable Transmission). The two operating modes, optimized for low and high speeds, are supplemented by fixed transmission ratios.
The two power-split ECVT sections allow the drivetrain to run at continuously variable speeds and ensure full, highly efficient hybrid functions throughout the entire operating range of the car.
It can be driven on electric power only for up to 2.5 km, on the engine alone, or with a combination of both power units. Depending on driving conditions, the electric motors can also be used for both accelerating and regenerative braking.
BMW claims speeds of up to 60 km/h are possible on the battery alone.
In the case of brake regeneration, the brake forces created when coasting and when applying the brakes, supply power to the high-voltage energy storage unit to provide an increase in electric power.
When the driver needs all available performance to accelerate, one of the two electric motors acts as a generator, converting some of the engine's power into electrical current that is subsequently fed to the battery or the second electric motor.
The second electric motor then converts the power coming from the first electric motor or from the battery back into mechanical power for the output drive shaft on the transmission.
What, I asked, happens when you are running on just the battery with the engine shut off and you have to panic brake? The X6 Hybrid has an electric vacuum pump that supplies full braking if the engine is off or there is an electrical fault.
With the technological stuff out of the way, how does it drive?
The two-mode system was developed in partnership with GM and Chrysler and I have a lot of experience with the two-mode system on GM trucks.
Where the X6 is different is in the sheer, effortless acceleration. Even on the battery, I could zip up to 49-50 km/h before the engine kicked in. I tried for the 60 km/h BMW claims but couldn't do it.
With rear tires almost as wide as me, traction was solid and immediate.
The press launch of the ActiveHybrid X6 was held in Miami where urban streets are narrow and abrupt lane changes by savvy locals is a constant danger, especially in a vehicle as high, wide and handsome as this.
There are no such things as winding routes and tall mountains to climb, just four- and five-lane wide highways where traffic is thick, and again, locals switch lanes without a care or turn signal.
I always think of AWD in rain, snow and gravel situations, but BMW's xDrive has sensors that measure the amount of wheel slip between the front and rear and can vary the normal 40:60 front:rear balance in milliseconds. Unlike normal "slip and grip" AWD, xDrive anticipates what's coming next and responds before a wheel starts to spin.
There is so much more to this vehicle like the hybrid specific auto start/stop system that I could go on and on.
But it is important to note that this is also a fully equipped X6 with all the features and road holding ability one expects in a BMW costing over $90,000 (price not finalized at this writing).
Inside, all the primary controls are exactly where BMW has put them since day one, in the right place.
I owned a series of BMWs in the 1980s. I got behind the wheel of the X6 Hybrid, closed my eyes, and reached out to find the steering wheel and shifter right where I expected them to be.
That's one of the things that make a BMW a BMW.
The other is the handling.
There's something they do at BMW that results in a ride that is solid to the senses yet with just the right weight to the feel of the wheel.
This communication is so highly developed that you can actually feel the degree of bite of the front tires going into a turn at speed.
Wrapped up in a premium luxury package, all of this comes with a 20 per cent saving on fuel.
It's like having your green cake and enjoying it too.
Here's to green power!
AT A GLANCE
Premium luxury CUV hybrid.
4.4-litre, twin turbo V8, two electric motors (480 hp, 575 lb/ft combined).
European city/highway combined loop, 9.9L/100 km
Est. $91,000 plus