For buyers who desire serious performance, the 2015 BMW M5 is a resounding case of having your cake and eating it, too. The idea's not a new one, nor does it belong to BMW alone, but the satisfaction one derives from a performance-enhanced version of an otherwise stately sedan is positively alluring. The formula is a simple one: Start with a five-passenger luxury sedan, then add a high-output engine, sporty suspension, sticky tires and subtle styling elements and badges that only hint at the sleeper sedan's true capabilities. The 2015 BMW M5 has all that, and more.

Based on BMW's 5 Series luxury sedan, the M5 is a ludicrously fast and surprisingly agile sedan. The car's twin-turbocharged V8 engine produces 560 horsepower in standard tune, and the optional Competition package bumps that to 575 hp and buttons down the suspension even more. You have your choice of BMW's seven-speed dual-clutch automated manual transmission (M-DCT) or, unusual for this class, a conventional six-speed manual gearbox. Either one will deliver you to 60 mph in the 4-second range and return about 20 mpg if you exercise some prudence. And thanks to the M5's standard torque-vectoring rear differential and driver-adjustable adaptive suspension, this big sedan is still very capable and enjoyable on twisty back roads, too.

Be that as it may, the fifth-generation BMW M5 (the F10 generation to those in the know) gives greater priority to luxury, technology and interior room than earlier M5 sedans did. Part of the reason for this is that the M5 and 5 Series now share much of their fundamental architecture with the company's larger 7 Series sedan. Perhaps, as a result, the current BMW M5 is not quite as engaging to drive as earlier versions. There are a number of other super-sedans that can keep pace with it, and do so with a sharper edge or bolder statement. The all-wheel-drive Audi RS 7 and Porsche Panamera both defy at least a couple laws of physics. The supercharged Jaguar XFR-S is dripping with English hooligan style, and the Mercedes-Benz E63 AMG is the M5's biggest nemesis, historically as well as dynamically.

All of these cars are exciting in their own right and deserve consideration if performance is your overriding priority. Still, even with its slightly more relaxed character, the 2015 BMW M5's blend of athleticism and refinement will undoubtedly strum the right chords for plenty of buyers seeking a high-performance sedan that doesn't skimp on luxury amenities.

The 2015 BMW M5 is a high-performance, four-door luxury sedan with seating for five. Standard features include 19-inch alloy wheels, summer performance tires, a driver-adjustable adaptive suspension, adaptive xenon headlights, keyless ignition and entry, adaptive cruise control, front and rear parking sensors, auto-dimming mirrors, a sunroof, dual-zone automatic climate control, a power tilt-and-telescoping steering column, leather upholstery, 16-way power sport front seats, heated front seats with memory settings, aluminum interior trim and split-folding rear seats. Standard electronics features include the iDrive electronics interface, a navigation system with traffic data and 3-D rendering, voice control, a rearview camera, Bluetooth phone and audio connectivity, BMW Assist telematics and a 16-speaker Harman Kardon audio system with a six-CD changer, HD radio, satellite radio, a USB input and 20GB storage for audio files.

The Competition package brings 15 extra horses via unique engine and exhaust tuning, along with black chrome tailpipes and special 20-inch wheels, a more aggressive state of tune for the steering, suspension, stability control system and rear electronically controlled, limited-slip M differential.

The optional Driver Assistance Plus package adds lane-departure and blind-spot warning systems, a forward collision mitigation system with pedestrian detection, speed-limit information and side- and top-view cameras. The Night Vision with Pedestrian Detection further adds an infrared camera that detects objects/pedestrians and sends images and warnings to the dashboard display screen. Expanded for 2015, the Executive package adds a power-operated trunk lid, soft-close doors, a heated steering wheel, ventilated and massaging functionality for the front seats, four-zone automatic climate control, heated rear seats, a power rear sunshade, manual rear side window shades, a head-up display, LED headlights with automatic high-beam control, cornering lights and three years of BMW Assist's concierge services.

Stand-alone options include interior and exterior trims/finishes, 20-inch wheels, carbon-ceramic brakes, a rear seat entertainment system, an upgraded 16-speaker Bang & Olufsen surround-sound system, a rear-seat entertainment system (with dual 9.2-inch screens) and smartphone app integration that includes LTE WiFi connectivity and various mobile-office functions.

Finally, a 30th Anniversary Edition M5 will be offered this year. Festooned with unique Frozen Dark Silver paint, a black simulated suede/leather interior (with a contrasting anthracite headliner) and commemorative wheels and badging, the "30 Jahre M5" (German for "30 years of the M5") is the most powerful production car BMW has ever offered. Starting with a Competition package-equipped M5, the BMW M division engineers increase the turbocharger's pressure and remap the engine control unit to squeeze in an additional 25 horses for a total of 600 hp. The electronic driving aids are suitably recalibrated to take full advantage of the greater engine output and a one-day M driving school is also included to recalibrate the potential owner. Of the worldwide allotment of 300 total, 30 of these special M5s are headed to the United States.

The rear-wheel-drive 2015 BMW M5 is powered by a turbocharged 4.4-liter V8 engine that produces 560 hp (575 hp with the Competition package or 600 hp for the 30th Anniversary limited-edition model) and 500 pound-feet of torque (516 lb-ft on the Anniversary model). A seven-speed automated-manual M Double Clutch Transmission (M-DCT) with steering-wheel-mounted paddle shifters comes standard, though a conventional six-speed manual transmission is a no-cost option aimed at purists. All M5s feature a defeatable automatic stop-start engine function and a torque-vectoring rear differential.

The EPA estimates that the M5 will earn 17 mpg combined (15 city/22 highway) with the six-speed manual transmission and 16 combined (14/20) when equipped with the seven-speed automated manual.

In Edmunds testing, a manual-shift M5 (absent the Competition package) hit 60 mph in 4.5 seconds. BMW says the M-DCT is quicker still at 4.1 seconds, partly due to a pretty sophisticated launch-control system. And although it's unlikely we'll ever see one, much less drive one, the 30th Anniversary edition is said to run to 60 mph in just 3.7 seconds.

The 2015 BMW M5 comes standard with ventilated antilock disc brakes, traction and stability control, cornering brake control, brake-fade compensation, automatic brake drying and hill-hold assist. It also comes with front airbags, front seat-mounted side airbags, knee protection, side curtain airbags, active front-seat head restraints, a rearview camera and a 10-year subscription to BMW Assist's emergency services. Also standard is an impact sensor that disconnects the battery from the alternator, fuel pump and starter and then turns on hazard lights and interior lights and unlocks all doors.

Carbon-ceramic brakes are a stand-alone option, as is a night-vision camera system capable of identifying and displaying oncoming animals, objects or people beyond the range of the car's headlights. In addition, the Driver Assistance Plus package adds lane-departure and blind-spot warning systems, a frontal collision mitigation system with pedestrian detection, speed-limit information and side- and top-view cameras.

In Edmunds brake testing, an M5 with the standard brake setup took 111 feet to stop from 60 mph. This is an impressive performance for a nearly 4,400-pound sedan.

With between 560 and 600 horses on tap, the 2015 BMW M5 feels extremely quick in virtually any situation. Its twin-turbocharged V8 exhibits very little turbo lag, though it doesn't feel truly potent until engine speed reaches 3,000 rpm. It also doesn't begin making typically throaty V8 sounds until this point, and even then, you'll need to have the windows down to enjoy it. Leave the windows up and the engine's actual voice is unable to penetrate the tightly insulated luxury sedan interior.

The seven-speed automated manual transmission shifts as smoothly as a regular automatic in its comfort setting, yet it is lightning-quick to respond in its Sport and Sport+ settings and when manual shifts are summoned (via the steering wheel paddles or the shift lever itself). The conventional six-speed manual is appropriately notchy for a sporty feel, and we love how it blips the throttle for you as soon as you move the lever into a lower gear, helping you nail the perfect downshift.

However, with its various engine, suspension, steering and transmission settings, the M5 can be a case of too many choices on the menu. Sure, this tailor-made adjustability is appreciated, but with over 100 possible combinations, many of them have little to no value. To its credit, the M5 is mannerly in its more relaxed settings and tightens up for serious back-road shenanigans in its sharpest settings.

During extreme cornering maneuvers, the M5 remains utterly flat and composed. The trade-off can be a firm ride, even in the softest suspension setting, especially on Competition-package models, which lose 10mm of suspension travel. This is definitely something to note if you regularly drive on less than pristine pavement. The steering earns its share of disappointment, too, as the sportier settings merely increase the effort level without improving the feel. On the other hand, the standard brakes work brilliantly and provide great feedback. Still, anyone planning to take a BMW M5 to a weekend track day or two would be wise to upgrade to the optional carbon-ceramic discs, which are less prone to fade under hard use.

Compared to its direct competitors, the BMW M5 earned an Edmunds.com "B" rating for its relatively high cost and subpar drivability (at least in the company of other elite performance sedans).

The M5's interior is trimmed in copious amounts of leather and aluminum. The driver and front passenger are spoiled with splendid, 16-way-adjustable seats with articulating headrests and backrests and adjustable side bolters, making it virtually impossible to be uncomfortable. Furthermore, they look as good as they feel. The steering wheel has a slightly retro look with its thin spokes, but a meaty, contoured rim makes it a joy to grip. One of the few knocks against this interior is a dearth of storage slots for smaller items like smartphones and wallets.

BMW's iDrive system continues to evolve, and works quite well in the M5. It features one of the widest screens in the automotive realm; its crisp, color graphics are state-of-the-art; and an elegant control knob in the center console governs most entertainment, climate-control and navigation functions, as well as various vehicle settings. Touchpad entry is an emerging tech feature, and BMW enables you to input navigation information by freehand tracing numbers and letters with a fingertip on top of the iDrive control knob. Although the iDrive interface is generally straightforward, the sheer number of menu paths necessitates taking some time to familiarize yourself after you buy the car. Fortunately, most of the adjustable drivetrain and dynamics features have their own buttons around the gearshift lever for quick access.

Rear-seat passengers fare quite well, just as they do in any other 5 Series as long as nobody needs a cupholder (the M5 has two up front and none in the backseat). The rear seatback also splits and folds, expanding the usability of the 14-cubic-foot trunk.