Few models have sustained such a high level of excellence as the BMW 5 Series. Over the course of five generations, the 5 has consistently been one of the best automobiles you could buy, period. Now it's time for generation six to take its place in the automotive world in the form of the 2011 BMW 5 Series.

This new 5 certainly has a tough act to follow, however, particularly in regards to styling. The last generation represented a radical change to the 5 Series' previous evolutionary look, sporting curves and flourishes that attracted some buyers but repulsed others. For better or worse, the 2011 5 Series returns to a more conservative appearance, one that shows a stronger family resemblance to other BMW sedans. Though it may lack its predecessor's visual extravagance, the new 5 remains a very attractive sedan (the wagon has been discontinued for the United States).

It's also been given a full shot of adrenaline. The base 528i's 3.0-liter straight-6 is up by 10 horsepower to 240 hp. The 535i's turbocharged 3.0-liter straight-6 is unchanged in terms of output, but a switch to a new turbocharger design has improved low-end torque and fuel economy. The prize for the biggest punch goes to the 550i; this year it gets the same 400-hp 4.4-liter turbo V8 as the 7 Series. BMW has also introduced a new eight-speed automatic transmission that boosts fuel economy and acceleration compared to last year's six-speed auto. Notably, a manual transmission is still available on all models.

As the 2011 550i is about 300 pounds heavier than last year's model, the extra power will certainly be put to use. Part of that weight gain is due to the car's increased size, as it's now both longer and wider.  Mechanically, it has a lot in common with the 7 Series and features the 7's new multilink front suspension and a new electric-assist steering rack. New feature highlights include the latest (and greatly improved) iDrive system, an automated parallel parking system, a head-up display, top-view and sideview cameras and a blind-spot monitoring system.

Taken as a whole, a lot of good things have happened for the latest 5 Series. If there's a downside, it's likely that the larger size has moved the 5 off of its previous Goldilocks slot of being the "just right" choice between the smaller 3 Series and bigger 7. On tight roads especially, the car's larger size and 2-ton curb weight can seem a bit too much for a midsize sedan. This aside, however, the latest 5 is utterly brilliant. Sportier than the 2011 Mercedes E-Class, cleaner-looking inside than a 2011 Audi A6 and roomier than a 2011 Jaguar XF, the 2011 BMW 5 Series continues to be one of the best vehicles you can drive, period.

The 2011 BMW 5 Series sedan is offered with three available engines that correspond to three trim levels: 528i, 535i and 550i. The 535i and 550i are also offered as "xDrive" all-wheel-drive variants.

The 528i comes standard with 17-inch wheels, rain-sensing wipers, a sunroof and power and heated side mirrors. On the inside you'll find leatherette upholstery, eight-way power front seats, driver memory functions, dual-zone automatic climate control, a power tilt-and-telescoping steering wheel, the iDrive control interface, Bluetooth, BMW Assist emergency telematics and a 12-speaker CD audio system with HD radio.

The 535i is equipped in a similar fashion but includes 18-inch wheels and adaptive xenon headlights. The 550i adds leather upholstery, upgraded front seats, parking sensors, auto-dimming mirrors, interior ambience lighting and a hard-drive-based navigation system with voice controls and real-time traffic. These features are optional on the 528i and 535i.

Opting for the Dynamic Handling package equips the 5 Series with an adaptive suspension. Required for this package is the Sport package, which includes 19-inch wheels, performance tires, special exterior trim and the 14-way multicontour front seats.

Other major options, which may or may not be grouped into other packages, include keyless ignition/entry, a night-vision camera, automatic high-beam headlights, active cruise control, active four-wheel steering (535i and 550i), an automatic parallel-parking system, sideview and top-view cameras, a rearview camera, a premium audio system, an iPod/USB adapter, satellite radio, a rear sunshade, heated and ventilated front seats, rear climate control, a rear-seat entertainment system, a head-up display, a heated steering wheel and smartphone integration.

The entry-level 528i comes with a 3.0-liter straight-6 engine that's rated at 240 hp and 230 pound feet of torque. Going with the 535i gets you a turbocharged variant of that engine that cranks out 300 hp and 300 lb-ft of torque. The 550i has a turbocharged 4.4-liter V8 that produces 400 hp and 450 lb-ft of torque. Rear-wheel drive is standard, with xDrive all-wheel drive being optional on the 535i and 550i.

Power is directed through either a standard six-speed manual transmission or an optional eight-speed automatic with manual-shift control. The 528i, 535i xDrive and 550i xDrive only come with the automatic. A sport version of the automatic (it can make quicker shifts and comes with shift paddles on the steering wheel) is also optional.

In Edmunds testing, a 535i with the automatic accelerated from zero to 60 mph in 5.9 seconds; that's slower than last year's 535i but still respectable for the segment. EPA-estimated fuel economy is above average for the class. The 528i earns 22 mpg city/32 mpg highway and 25 mpg combined. The automatic-equipped 535i checks in at 20/30/24 mpg, and the automatic 550i is still respectable at 17/25/20 mpg. All-wheel-drive versions of the 535i and 550i drop by about 1 mpg across the board.

Standard safety equipment for the 2011 BMW 5 Series includes stability and traction control, antilock disc brakes, front-seat side airbags, side curtain airbags, active front head restraints and the BMW Assist emergency communications system. The stability control system integrates several features designed to improve braking performance, such as periodically wiping the brake rotors dry in wet conditions and automatically snugging the brake pads to the rotors when the driver abruptly lifts off the throttle.

When equipped with active cruise control, the 5 Series also comes with a pre-collision system that can warn the driver of the possibility of rear-ending a vehicle ahead. If a collision is imminent, it can also automatically apply the brakes.

The available lane-departure warning system alerts the driver via vibrations in the steering wheel if the car starts to veer out of its lane; the same sensation is felt for the available blind-spot monitor, which also utilizes side-mirror indicators when other vehicles move into the BMW's blind spots. A night-vision system is capable of displaying possible hazards that are otherwise out of regular headlight range.

In the government's new and more stringent 2011 crash tests, the 2011 BMW 5 Series earned a top five-star rating for overall performance, with four out of five stars being given for front-impact protection and five stars for side-impact protection. In Insurance Institute for Highway Safety testing, the 5 Series earned a top rating of "Good" in both frontal-offset and side-impact crash tests.

It wasn't too long ago that the high-performance M5 was throwing down 400 hp. Now you get that (plus a lot more torque) out of the latest 550i, which accelerates as quickly as a V8 sport coupe but without the pretentious bombast. Choosing the 300-hp 535i or even the less potent 528i is hardly like sitting in the cheap seats; most people will be more than satisfied with their power and fuel economy. With any engine choice, the new eight-speed automatic works exceptionally well, even when multi-gear downshifts are performed. We're happy that BMW continues to offer a manual transmission, though this choice is obviously meant for driving enthusiasts only.

If equipped with the optional adaptive suspension and active steering, the 2011 BMW 5 Series does an excellent job of providing both a comfortable ride and capable handling. The steering feel isn't as lively as what you'll get out of, say, a 3 Series, but the new electric-assist rack is still precise. On a curving road, the 5 is confidence-inspiring and unflappable. However, when the road tightens up, the car's larger size and 2-ton curb weight can make it seem a bit bulky, especially if you're driving a 5 without the adaptive suspension and steering.

Read our BMW 528i Long-Term 20,000-Mile Test

Both drivers and passengers will be quite pleased with the 5 Series' cabin. There's nothing particularly fancy going on, but the overall look of the dash is clean thanks to the standard iDrive interface that eliminates the need for a gaggle of buttons. The layout is quite similar to that of the 7 Series, with a center display screen and a configurable display in the gauge cluster. The iDrive controller, thanks to the new physical buttons and menu structure, is pretty easy to figure out and provides a large amount of customization of the car's features. Opting for the navigation system is recommended, as its screen is larger and much better looking than the standard center display.

The front seats are quite comfortable, with the optional multicontour seats in particular providing an impressive amount of adjustability. In back, there's enough room for a pair of 6-foot adults to be comfortable, and the backseat is nicely contoured and padded. The trunk, at 14 cubic feet of luggage capacity, is smaller than average for this segment.