Used 2015 BMW 6 Series Gran Coupe

Despite its name, the 2015 BMW 6 Series Gran Coupe is a midsize sport sedan with a high level of luxury amenities and a measure of style that you won't find in the similarly sized and mechanically related 5 Series sedan. It's expensive for what you get, though, so we'd advise you to check out the competition as well.

Think a luxury sedan doesn't necessarily have to be squared-off and formal? So do a lot of automakers these days, including BMW. The 2015 BMW 6 Series Gran Coupe is one of the latest luxury sedans to feature a coupelike profile and roof line. But know in advance that, as with most of the new generation of sedans that want to be coupes, there are compromises that come with the territory.

The 6 Series Gran Coupe is essentially a cross between the similarly sized BMW 5 Series sedan and the similarly shaped and styled 6 Series coupe. The result is far more backseat room than you'd find in the rather cramped coupe, but less than in a traditional luxury sedan. The Gran Coupe's lower roof line markedly cuts headroom in the rear, and a nearly full-length center console effectively limits the rear seat's capacity to two adults. The rear seat has a seatbelt for the center position, but the center console allows almost no legroom. In other words, there's a trade-off for its slinky styling.

There's certainly plenty of power on hand to back up the looks, though. The standard turbocharged six-cylinder engine for the 640i Gran Coupe is lusty in both performance and sound, while the V8-powered 650i get a thunderous 445 horsepower. A standard eight-speed automatic transmission wrings the most performance and frugality out of either engine and features steering wheel paddles if you want to shift it yourself. Both models are available with rear- or all-wheel drive.

You'll find the Gran Coupe's style has another trade-off, too: It's more expensive than a comparable BMW 5 Series sedan and easily invades into the price territory of the 7 Series. It's also considerably more expensive than similarly slinky and sport-oriented coupe-sedans, even if it does come with abundant standard equipment. An Audi A7 or S7 are cheaper than the respective 640i and 650i, as is the Mercedes-Benz CLS550. The Porsche Panamera is similarly priced and offers more practicality, among other virtues. There's no question, though, that BMW knows how to turn out remarkably polished luxury sedans and coupes. The Gran Coupe is an excellent combination of the two.

The 2015 BMW 6 Series Gran Coupe is a four-door sedan with coupelike styling. Two primary trims are offered: 640i and 650i, which correspond to their engine. Versions with "xDrive" in their name come standard with all-wheel drive.

Standard on the 640i Gran Coupe are 18-inch wheels, an adaptive suspension, automatic and adaptive xenon headlights, LED foglamps, automatic wipers, front and rear parking sensors, a rearview camera, power-folding and auto-dimming mirrors, keyless ignition and entry, cruise control, a tilt-only sunroof, dual-zone automatic climate control, heated eight-way power front seats (with four-way lumbar adjustments and memory functions), leather upholstery, a power tilt-and-telescoping steering wheel and an auto-dimming rearview mirror. Electronic features include Bluetooth phone and audio connectivity, a navigation system, real-time traffic, voice controls, the iDrive electronics interface with an integrated touchpad on the controller and smartphone app integration, and a nine-speaker sound system with a CD player, HD and satellite radios, a USB/iPod interface and an auxiliary audio jack.

The 650i features a V8 engine in place of the 640i's six-cylinder and adds 19-inch multispoke wheels, 16-way power "multicontour" seats (with four-way lumbar adjustment and adjustable side bolsters), upgraded leather upholstery and a 16-speaker premium sound system.

There are several optional packages available on both models. The Cold Weather package provides heated rear seats and a heated steering wheel, and the Lighting package adds LED headlamps and automatic high beams. The Driver Assistance Plus package features front-side and top-view cameras, speed-limit information and BMW's "Active Driving Assistant," which bundles a blind-spot warning system, low-speed collision prevention (with pedestrian detection), lane-departure warning system and a frontal collision warning system.

The Executive package adds soft-close doors, a head-up display, four-zone climate control, ventilated front seats, telematics concierge services and a premium audio system. The 640i's version of this package includes the multicontour seats, while the 650i version adds a power rear sunshade, manual rear window shades and ceramic-trimmed controls. These items are available as individual options on the 640i.

The M Sport package includes most of the Executive package content plus 19- or 20-inch double-spoke wheels, lower body aero styling, a unique three-spoke steering wheel, a simulated-suede headliner and a higher (155 mph) top speed limiter. The BMW Individual Composition package essentially grants you access to special-order leather and wood trim hues.

Individual options include adaptive suspension stabilizer bars (known as Adaptive Drive), enhanced "Active Steering" with rear-wheel steer (not available on xDrive models), a night-vision camera, adaptive cruise control, extended leather upholstery, automated parallel parking assist and a 16-speaker Bang & Olufsen surround-sound audio system. Some of the package features are available as individual options as well.

Powering the 2015 BMW 640i Gran Coupe is a turbocharged 3.0-liter inline six-cylinder engine that makes 315 hp and 330 pound-feet of torque. Fuel economy for the rear-wheel-drive 640i is 24 mpg combined (20 city/31 highway). The all-wheel-drive 640i xDrive is just marginally thirstier at 23 mpg combined (20 city/29 highway). Edmunds instrumented testing recorded a 5.7-second 0-60 time in the rear-drive 640i Gran Coupe, which is average for this class of car.

The 650i Gran Coupe packs a turbocharged 4.4-liter V8 that generates 445 hp and 480 lb-ft of torque. Fuel economy drops significantly with the V8, to 20 mpg combined (17 city/25 highway) for the rear-drive 650i and 19 mpg combined (16 city/24 highway) for the 650i Gran Coupe xDrive. In Edmunds testing, a rear-drive 650i Gran Coupe hit 60 mph in 5.2 seconds. Although that's average for V8-powered midsize luxury sedans, the Audi S7 and Mercedes-Benz CLS550 are quicker.

Standard safety equipment includes antilock brakes with advanced standby and drying features, traction and stability control, front-seat side airbags, front knee airbags and active front head restraints. Also standard are front and rear parking sensors, a rearview camera and the BMW Assist emergency communications system, which provides automatic crash notification, remote unlocking, stolen vehicle recovery and on-demand roadside assistance.

The optional Driver Assistance Plus package features front-side and top-view cameras, speed-limit information and BMW's "Active Driving Assistant," which bundles a blind-spot warning system, low-speed collision prevention (with pedestrian detection), lane-departure warning system and a frontal collision warning system.

In Edmunds brake testing, the 640i Gran Coupe came to a stop from 60 mph in a short 110 feet – impressive, but typical for a car equipped with summer tires. A similarly outfitted 650i stopped in 114 feet.

Its acceleration numbers may be nothing special, but the 2015 BMW 640i Gran Coupe certainly feels quick in everyday driving. Its turbocharged inline-6 picks up steam rapidly as the revs climb, and the automatic transmission is on point as well, providing quick and timely downshifts. The 650i's turbocharged V8 feels downright decadent, as it unleashes a seemingly endless flow of thrust, moving the big sedan down the road with authority.

Like other BMWs, the 6 Series Gran Coupe has that unflappable Germanic feel at high speeds, yet somehow manages to feel smaller than it really is when you drive it around turns. All the while, the ride quality is firm, yet suitably luxurious for a car of this price and level of prestige.

That said, we're not so enthusiastic about how the 6 Series Gran Coupe feels when equipped with the optional "Active" steering and stabilizer bars (Adaptive Drive). These bits of tech lend a somewhat unnatural feel when hustling the car along a back road. In particular, the steering lacks the company's trademark road feel, while the sophisticated stabilizer bars are actually too effective, decreasing body roll to the point that you no longer have a sense of how hard you're pushing the car.

As with most BMWs, the Gran Coupe's interior is driver-focused in design, with surfaces trimmed with top-quality materials. Unlike with cheaper BMWs, though, you get standard leather upholstery and the option of other leather-trimmed interior surfaces and even ceramic-trimmed buttons and knobs. Depending on your preferences and use of the option choices, the appearance of the cabin can range from elegantly minimalist to edgy and avant-garde.

The front seats are superbly comfortable and are set low, reinforcing the car's sporty character. Yes, rear seat passengers fare better than in the 6 Series coupe (there's markedly more legroom, mainly), but the backseat is nevertheless more confining than in the 5 Series sedan due to a significant reduction of headroom and the so-called "+1" center rear seating position that is really only useful for children on very short trips. This is a result of the extended center console filling in the space where the "hump" would normally be, bringing center legroom from reduced to nonexistent.

As with other 6 Series models, the 2015 Gran Coupe also features BMW's improved iDrive control interface that manages entertainment, navigation and phone functions, as well as various vehicle settings. For 2015, iDrive's control knob has grown in size and gained a touchpad, granting the ability to draw letters and numerals with your finger on the controller's touchpad surface. There's a lot of functionality here, and although we advise you to take some time to study the various features before you hit the road, iDrive is notable for its sharp graphics, fast processing times and logical menu structure.

Trunk capacity goes the way of rear-seat headroom in the 2015 Gran Coupe. There are just 13.0 cubic feet of total cargo capacity and the trunk lift-over is rather high. At least the rear seat has split-folding functionality and an armrest pass-through to help improve utility.