Mark it down: 2011 was the year hybrids went mainstream.
For the first decade the technology existed, fuel economy was the only measuring stick that mattered. The hybrid that burned the least gasoline won. It was as simple as that.
Hybrid technology has migrated from specialized models like the Toyota Prius into every corner of the auto industry.
It’s key to vehicles from the $100,000-plus BMW ActiveHybrid 7 to the sub-$30,000 Buick LaCrosse eAssist, from elite sporty vehicles like the Porsche Cayenne to family haulers like the Toyota Highlander.
That means significant fuel savings for everyday drivers, but it raises a new challenge for hybrids. They must match or beat conventional cars not just on fuel consumption, but also comfort, convenience, performance and value.
One of the most supremely comfortable luxury sedans in the world, BMW’s 7-series improves its fuel economy and performance significantly with added hybrid systems.
An $18,000 price premium over the gasoline-powered 750Li undermines the ActiveHybrid, which the EPA estimates will save its owners around $520 a year. The car also suffers from reduced trunk space and auto-stop and regenerative braking systems that need more refinement.
Prices for the 7-series hybrid start at $102,300 for the regular-wheelbase 750i ActiveHybrid. The long-wheelbase 750Li ActiveHybrid adds 5.5 inches of length to create a limo-like backseat and raises the base price to $106,200.
All 7-series hybrids come with an eight-speed automatic transmission, 4.4-liter twin-turbo V8, small supplementary electric motor and lithium-ion battery.
I tested a long-wheelbase 750Li ActiveHybrid that cost $109,100. All prices exclude destination charges.
The 750Li hybrid competes with other large luxury sedans like the Audi A8L, Jaguar XJL, Lexus LS 600h L hybrid and Mercedes-Benz S 400 hybrid.
The BMW is what’s sometimes called a mild hybrid. Its hybrid system augments engine output, but lacks the power to move the 7-series on electricity alone.
Many of the coming cars that use hybrid technology will have that kind of system, because it costs less than a more powerful system that can drive the vehicle in all-electric mode.
The 7-series’ electric system boosts the engine’s output to 455 horsepower and 515 pound-feet of torque.
That extra power combines with a transmission that offers two more gears than the 750Li’s six-speed. The net result: The hybrid hits 60 m.p.h. in a blistering 4.8 seconds , 0.4 seconds quicker than the non-hybrid.
The hybrid’s EPA fuel economy rating in combined city and highway driving improves 3 m.p.g. to 20 m.p.g. compared with a standard 750Li. The A8L, LS 600h L and S 400 all match or beat the BMW hybrid’s fuel economy. They have less power and slower acceleration, though.
The battery pack reduces the 750Li’s luggage space by a cubic foot. It also adds a significant 198 pounds to the car’s curb weight. The extra mass affects handling. The ActiveHybrid 7 feels softer and less precise than its lighter sibling.
The regenerative brakes, which channel some of the energy from stopping the car back to the battery to reduce fuel consumption, affect pedal feel.
It’s hard to smoothly slow the ActiveHybrid 7 to a stop. There’s also a noticeable shudder when the engine restarts after shutting down when the car is halted.
In the best hybrids, there’s no shake or vibration. You’re only aware of the engine restarting if you watch the tachometer.
Steering feel is surprisingly poor, lacking the quick, linear feel BMWs usually deliver.
The 750Li shares some of the non-hybrid 7-series’ virtues, however. Its sleek shape and sumptuous interior embody modern luxury. Passenger space and comfort are exceptional.
The 2011 750Li ActiveHybrid feels like exactly what it is: a first try. I’m sure BMW’s future hybrids will be as spectacular as its conventional models, but the hybrid sedan lacks the utter refinement 7-series owners should expect.
Source: MCT Information Services