In the 40 years the BMW 5 Series has been in production in its various iterations, it has come to define the midsize luxury sedan market, and for good reason. A steady stream of improvements and innovations, plus an admirable blend of comfort, craftsmanship and performance, has set this midsize BMW apart from the middle-of-the-road cars in its market segment.

The 2013 BMW 5 Series proudly carries on this tradition, although its core message of performance has been obscured by luxury. When this generation of the 5 Series debuted two years ago, it took to the stage with larger dimensions and a decidedly more relaxed personality. For those who put a premium on comfort and space, the compromise was certainly justified.

But don't think for a second that the BMW 5 Series is a laggard. Even the entry-level 528i's turbocharged four-cylinder engine has the decisive response of an inline-6, yet delivers 28 mpg in combined driving. For those who put a greater emphasis on power, the 535i with its turbocharged inline-6 and the 550i with its V8 will surely satisfy your cravings. Then there's the raucous M5 with its raucous twin-turbo 560-horsepower V8 (a model covered in a separate review). The only exception is the ActiveHybrid 5, which hardly seems to justify its marginal fuel savings at its high price.

Whatever your leanings, it seems there's a 2013 BMW 5 Series to suit you. But those in the market for a midsize luxury four-door would also do well to check out some of its competitors. The rare driver who yearns for the days of BMW's "ultimate driving machine" will find that spirit alive and well in the 2013 Audi A6 and, to a lesser degree, the 2013 Lexus GS 350. Others who seek even more luxury will likely find the 2013 Mercedes-Benz E-Class and Jaguar XF to their liking. If you're undecided among any of these choices, rest assured; there's not a bad one in the bunch.

The 2013 BMW 5 Series is a midsize luxury sedan available in four trim levels that correspond with engine choice: 528i, 535i, 550i and ActiveHybrid 5. The high-performance M5 model is reviewed separately.

Standard equipment on the 528i includes 17-inch wheels, adjustable driving settings (which alter suspension, steering, throttle and automatic transmission response), automatic and adaptive bi-xenon headlights, LED running lights, foglights, automatic wipers, heated mirrors, a sunroof, cruise control, auto-dimming mirrors and keyless ignition/entry. Inside you get dual-zone automatic climate control, eight-way power front seats (with four-way power lumbar), driver memory functions, split-folding rear seats, leatherette premium vinyl upholstery and a power tilt-and-telescoping leather-wrapped steering wheel. Electronic features include the BMW Assist emergency communications system, Bluetooth, the iDrive electronics interface and a 10-speaker sound system with a CD player, HD radio, an auxiliary audio jack and an iPod/USB audio interface.

The 535i gets a six-cylinder engine, 18-inch wheels and leather upholstery. The ActiveHybrid adds four-zone automatic climate control, a navigation system with real-time traffic and a larger iDrive screen. The 550i gets a V8 engine, front and rear parking sensors, a rearview camera and 14-way power front seats, but reverts back to the dual-zone climate control. All of these extra luxury and convenience features are available on the respective lower trim levels.

There is a wealth of other options available on every 5 Series trim, many of which are available within packages or as individual options. These include a power trunk lid, active cruise control, an automatic parallel parking system, active steering, a blind-spot warning system, a lane-departure warning system, automatic high beams, headlight washers, side/top-view parking cameras, a head-up display and an infrared night-vision display. Inside you can add four-zone automatic climate control, heated front and rear seats, ventilated front seats, a heated steering wheel, a sport steering wheel, a 16-speaker Bang & Olufsen surround-sound audio system, smartphone app integration, a power rear sunshade, manual rear side sunshades, a rear-seat entertainment system, satellite radio and a premium sound system.

The Sport package adds bigger wheels, adaptive suspension dampers, a sport steering wheel, an increased top speed and the 14-way seats. The M Sport package adds to those items a special aerodynamic body kit, special wheels and an M Sport steering wheel.

The 2013 BMW 528i is powered by a turbocharged 2.0-liter four-cylinder that produces 240 horsepower and 255 lb-ft of torque. As with all 5 Series models, rear-wheel drive is standard and "xDrive" all-wheel drive is optional. Also standard are an eight-speed automatic transmission and an automatic stop-start function that shuts down the engine when the car stops in order to save fuel. In Edmunds performance testing, a 528i went from zero to 60 mph in 6.4 seconds, which is about average for base-model midsize luxury sedans. BMW-estimated fuel economy is 24 mpg city/34 mpg highway and 28 mpg combined with rear-wheel drive and 22/33/26 with all-wheel drive.

The BMW 535i gets a turbocharged 3.0-liter inline-6 engine that produces 300 hp and 300 lb-ft of torque. Rear-wheel-drive models get a standard six-speed manual or an optional eight-speed automatic; all-wheel-drive models are automatic only. Automatic stop-start is standard. In Edmunds performance testing, a rear-drive 535i with the automatic went from zero to 60 mph in 5.9 seconds, which is average among comparable sedans. BMW-estimated fuel economy is 20/30/23 with the manual, 20/30/24 with rear-wheel drive and the automatic and 21/30/24 with all-wheel drive.

Powering the ActiveHybrid 5 is a turbocharged 3.0-liter inline-6 that is paired to an electric motor powered by a lithium-ion battery pack. Combined, they produce 335 hp and 300 lb-ft of torque and achieve a (disappointing) rating of an EPA-estimated 23/30/26 mpg. In Edmunds performance testing, the ActiveHybrid 5 took the slightest of leads over the 535i by accelerating to 60 mph in 5.7 seconds.

The BMW 550i gets a turbocharged 4.4-liter V8 that produces 400 hp and 450 lb-ft of torque. The same transmission and drive options from the 535i are available on the 550i, with the exception of auto stop-start. In Edmunds performance testing, a rear-drive automatic-equipped 550i went from zero to 60 in 5.2 seconds. EPA-estimated fuel economy is 17/25/20 with the automatic and rear-wheel drive, 15/22/17 with the manual and rear-wheel drive and 15/20/17 with all-wheel drive.

Standard safety equipment for the 2013 BMW 5 Series includes stability and traction control, antilock disc brakes, front-seat side airbags, side curtain airbags and active front head restraints. 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. Also standard is the BMW Assist emergency communications system, which includes automatic crash notification, an emergency response button, remote door unlock and stolen vehicle recovery.

When equipped with active cruise control, the 5 Series 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. A lane-departure warning system and a blind-spot monitor are optional. The night-vision system is capable of displaying possible hazards that are otherwise out of regular headlight range.

In Edmunds brake testing, various 5 Series models with the Sport package's summer tires came to a stop from 60 mph in distances ranging from 110-114 feet. Those are excellent numbers, but typical for summer tires. By comparison, the heavier ActiveHybrid 5 with all-season tires stopped in 125 feet: longer, but also about average.

In government crash tests, the 5 Series earned a top five-star rating for overall performance, with four out of five stars being given for overall 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 the frontal-offset, side-impact and roof-strength crash tests.

Among the many choices you have in the way the 2013 BMW 5 Series is configured, the 550i comes closest to justifying the company's traditional definition as the "ultimate driving machine." That said, 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. Likewise, the ActiveHybrid 5 uses the supplemental electric power more for performance than fuel economy. (To its detriment, though, the hybrid power plant is relatively unrefined in its launch and power delivery in low-speed stop-and-go traffic.)

Regardless of which engine you choose, the 2013 BMW 5 Series comes standard with BMW's Driving Dynamics Control, which alters the suspension, steering, throttle and automatic transmission response based on four driver-selected settings. In theory, it allows drivers to set up the car as they'd like, but overall this larger iteration of the 5 Series has lost the agility and communication of its predecessors. The steering transmits less feel, the larger dimensions make it feel bulky on tighter roads, and there's just a general feel of isolation that didn't exist before. Then again, its quieter cabin, more comfortable ride and lighter steering in parking lots should appeal to more buyers than before.

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 features a center display screen and a configurable display in the gauge cluster. The iDrive controller provides a large amount of customization of the car's features, though we think Mercedes' COMAND system is still a little easier to use overall. 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 unmatched degree 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.