2010 BMW X6 ActiveHybrid — First Drive Review
Although BMW initially shunned hybrids in favor of clean diesels and other alternative powertrains, the German automaker is joining the electrically assisted fray next year with not one but two gasoline-electric vehicles: the 2010 BMW ActiveHybrid 7 — our first drive of which you can read here — and the 2010 BMW ActiveHybrid X6.
Both models share ActiveHybrid badging and fall in the contradictory performance-hybrid segment, but their similarities end there. The 7 is a mild hybrid that uses an electric motor in its eight-speed automatic gearbox and a compact lithium-ion battery mounted in the trunk to assist acceleration and run the accessories; the X6 is a far more complex full hybrid. The latter's pair of motors and advanced electronic continuously variable transmission allow it to waft up to 1.6 miles and at speeds of up to 37 mph on electric current alone. Forget about Prius-like fuel economy, though, because the ActiveHybrid X6 is the most powerful hybrid yet produced, with the electric bits combining with a 400-hp, 4.4-liter twin-turbocharged V-8 to produce a total output of 480 hp and 575 lb-ft of torque. (When pressed on why it didn't choose to pair the hybrid system with the X6 xDrive35i's twin-turbo six-cylinder, BMW simply says that using the V-8 made for the largest jump in efficiency. Plus, the company added, the resulting vehicle would be slower.)
Two Modes and Lots of Explaining
Compared with the GM and Chrysler examples, which blend CVT operation with two electric motors and three planetary gearsets for a total of four fixed gear ratios, the X6's unit stirs in three additional, "virtual" ratios, effectively making the transmission a seven-speed for better dynamic performance. As with the normal X6, manumatic shifting is performed via the console shifter or wheel-mounted paddles. The two electric motors within the gearbox — rated at 91 and 86 hp and 192 and 206 lb-ft of torque, respectively — assist with high- and low-speed mobility while also helping to recapture wasted energy through regenerative braking. The juice, stored in a 2.4-kWh nickel-metal hydride battery pack under the floor of the X6's cargo hold (it lives where conventional X6 models keep their spare tires; run-flats are standard on the hybrid), is then fed back into the system and on to the drive wheels.
It Moves, Stops, and Turns
However, the preview-drive route BMW chose in and around downtown Miami offered little insight into the X6 hybrid's dynamic behavior. Cruising through the city, we noticed the engine smoothly and routinely shut off and restarted at stoplights (unless we were in sport mode or if the battery was nearly drained). Accelerating using electric-only power could be done with a fair amount of throttle, unlike in some other hybrids where the engine cuts in at even a hint of pedal movement. There occasionally was some hesitation when we quickly jumped to the accelerator and the hybrid system's electronic brain had to decide how best to direct the power to all the gears and motors, but the vehicle definitely was quick once it got moving. Despite the added 400-ish pounds of hybrid gear, BMW says the ActiveHybrid is only 0.1 second slower to 60 mph — 5.4 seconds — than the nonhybrid V-8 X6. We think a 5.2-second time is possible, given that our long-term X6 xDrive50i managed the task in 5.1. Top speed is electronically limited to 130 mph, and towing capacity is a substantial 6000 pounds.
Fuel Economy and Pricing
In terms of fuel economy, the X6 hybrid has an EPA city/highway rating of 17/19 mpg; for comparison, the xDrive50i is rated at 13/18. That should mean an improvement over our long-term X6's 15-mpg average, but there's no masking the twin-turbo V-8's considerable thirst when it's called on to move the X6's bulk with any haste.
Packaging as Confusing as the Drivetrain
Inside, a power-flow meter in the main infotainment screen tells you where all the juice is going, and a small gauge in the lower part of the tach shows battery status, the amount of electric boost, and brake-energy recuperation. The four-seat layout and maximum 60 cubic feet of storage remain, as does the vision-limiting, sloping rear hatch. Overall, comfort and refinement are high, however, and the latest iteration of iDrive is actually fairly intuitive to use. Major options include ventilated seats, a rear-seat entertainment system, an upgraded sound system, and a Cold Weather package that includes a heated steering wheel and heated washer squirters.
A Token Gesture
The company claims to have no other applications in store for the two-mode drivetrain and refuses to estimate how many X6 hybrids it will sell — likely very few. Given that, we're even more perplexed as to why this vehicle exists than we are the normal X6. When asked why no weight-saving measures were taken to improve efficiency and performance — as GM did with its hybrid SUVs — BMW baffled us further by saying it was focused solely on developing the fastest, most powerful, and best-driving hybrid ever. How, we wonder, are those goals at odds with reducing weight?
Although we commend BMW's effort to embrace full-hybrid technology, and even the resulting vehicle's capability, the motives behind it seem cemented in corporate hubris. For the few folks who crave a large, immensely powerful crossover and believe they could actually help Mother Earth with such a purchase, the ActiveHybrid X6 fills the bill. For us, we'll plant a couple of trees and take the X6 M for the same money.