Gasoline-electric hybrid versions of BMW's big, 2011 BMW 7-Series sedans come with the federal government's lowest fuel economy rating of all regular-production hybrids.
But the 750i and 750iL ActiveHybrids are the quickest hybrid luxury sedans in showrooms, jetting from 0 to 60 miles an hour in a sports car-like 4.7 seconds.
They're also the only hybrid sedans that mate a twin-turbocharged V-8 to an onboard electric motor. The result: a whopping 455 horsepower and peak torque of 515 foot-pounds starting at 2,000 rpm.
These newest and most high-tech 7-Series sedans come at an $18,000 price premium over base 750i models.
Starting manufacturer's suggested retail price, including destination charge, is $103,175 for the regular-wheelbase 750i ActiveHybrid. The longer-length 750iL hybrid starts at $107,075.
By comparison, the non-hybrid 2011 750i and 750iL have starting retail prices of $84,375 and $88,275, respectively.
Hybrid luxury sedan competitors to the 7-Series gas-electric hybrids include the 2011 Lexus LS600h L, which has a starting MSRP, including destination charge, of $112,225, and the 2011 Mercedes-Benz S400, which starts at $91,875.
Note that the Lexus hybrid uses a naturally aspirated V-8 for a maximum 438 horsepower, while the 295-horsepower Mercedes S400 has a V-6 powerplant.
As a result, the 2011 Mercedes S400 is rated at 19 miles a gallon in city driving and 25 mpg on the highway on the U.S. Environmental Protection Agency's fuel economy website, while the 2011 LS600h L is rated at 19/23 mpg.
The BMW 750i ActiveHybrid _ either regular wheelbase or long wheelbase _ comes in with a 17/24-mpg rating on the EPA's list. I averaged 20 mpg city/highway during the test drive.
This is a far cry from the top-selling gas-electric hybrid car _ the Toyota Prius, which is rated at 51/48 mpg with four-cylinder engine and electric motor.
Truth be told, a driver of a 7-Series ActiveHybrid can disable at least one of the features of the hybrid technology _ the automatic turning off of the gasoline engine at stops to conserve fuel _ by putting the gearshift lever into sport mode. This keeps the turbo V-8 at the ready for spirited and admittedly more traditional sporty driving.
A driver also can choose different suspension settings, throttle response and steering assist, and the sporty setting was palpably firmer in ride and crisper in handling than the normal mode.
These BMWs are considered mild hybrids because they are never propelled solely on electric power. Instead, electric power _ delivered via a lithium ion battery that stores energy from the electric motor _ supplements the gasoline engine and automatically does its business without any attention from the driver.
These BMWs do not plug in to electrical outlets. They generate electric power onboard as they are driven.
The test car was painted a special hybrid color _ Blue Water Metallic _ but that doesn't draw attention. The aerodynamically styled, 19-inch wheels do look different, however.
Doors on the 750i hybrid were heavy enough that I couldn't close them entirely by hand. Not to worry. Automatic door closing that seemed to suck the last bit of air out from between a slightly ajar door and the car frame, pulling the door snugly in place.
Inside, only minor changes in an otherwise well-crafted interior indicate this is a hybrid 7-Series. There's an instant mileage meter and battery status monitor in the instrument cluster, for example. And the display in the center of the dashboard has a graphic showing where the car's power is coming from. A bar chart shows 15 minutes of hybrid system activity.
It didn't take long once the car was on the road to notice this was a hybrid. There was a regular hesitation, almost a feeling the car was going to stall, as the engine restarted after automatically turning off at stoplights to conserve fuel.
This is the kind of sensation I noticed in early Honda and Toyota hybrids years ago. They have since fixed the problem for a more seamless transition.
But the 750i's regenerative brakes were excellent. Compared with the artificial and sometime unnerving feeling of other hybrids' brakes, the BMW brake pedal had a regular feel and strong response.
That was good, too, because the 750i ActiveHybrid felt ponderous. It weighs nearly 4,800 pounds, and the car felt heavy and not agile while winding around and around in a parking garage or moving through traffic on congested streets.
The car's spacious interior, with especially generous legroom of nearly 39 inches in the regular wheelbase 7-Series and an expansive 44.3 inches in the long-wheelbase model, is pleasing. Trunk space is a bit less than in regular 7-Series cars because hybrid components are stored at the back of the car.
The car was quiet. I didn't hear anything from a big truck next to me, and road and wind noise were minimal.
Rear door openings are good-sized for graceful entries and exits, and rear windows are sizable. But passengers have to look to find the carefully tucked place where they can insert fingers to pull a door closed. It's styled subtly into the trim of all four doors.
The hybrid 7-Series comes with many standard safety features, including head-protection and frontal air bags, electronic stability control, traction control, antilock brakes, brake fade compensation and brake drying systems. But a rearview camera is extra.