The BMW 640i Gran Coupe is essentially a 5-series BMW that emphasizes sex appeal over practicality. It shares its 116.9-inch wheelbase with the 5-series sedan and its 74.6-inch width with the 6-series coupe. At 197.2 inches (16.4 feet), it's longer than either of those cars and almost as long as a short-wheelbase 7-series. With a roof height of 54.8 inches, it's a substantial 2.8 inches lower than the 5-series and 1.4 inches wider. It seats four adults comfortably, a fifth in a pinch. Its trunk is smaller than the one in the 5-series and no bigger than the one in the 6-series coupe. And its long front overhang, unusual for BMW, scrapes its way up driveways and into gas stations.
It might appear that the 640 Gran Coupe makes no rational sense, but then again, neither do its two principal competitors, the Mercedes-Benz CLS and the Audi A7, both of which are more expensive and less practical than the E-class and A6 sedans, respectively, on which they are based. The fact is that all three of these so-called four-door coupes exist mainly because they look great.
In two dimensions, the BMW doesn't look different enough from other BMW models to really catch your eye, but when you see the Gran Coupe on the road, you'll most certainly notice it. It makes the 5-series look nerdy, the 6-series coupe look busy, and the 7-series look bloated. Like the Z4, this is a Bimmer you need to see in traffic to fully appreciate.
How much more expensive is the 640i Gran Coupe than other BMWs? It starts at a hefty $76,895, which is a very reasonable $2400 premium over a 640i coupe, but it's also some twelve grand over a comparably equipped 535i sedan, which isn't a cheap car to begin with. Start adding options and things get outrageously expensive very quickly. Our almost fully loaded test car's sticker shocks to the tune of well over $100,000, meaning its price premium over a similar 535i is equivalent to the full price of a Volkswagen GTI.
Then again, you can't get a 535i with twenty-inch wheels, full LED headlights, the ever-cool Bang + Olufsen stereo, or the Gran Coupe's leather-lined and contrast-stitched interior. Or the high-output version of BMW's award-winning turbo six. The 640i is the first "40i" version of the N55 single-turbo engine. (Other high-output "40i" cars, as well as the 1-series M Coupe, Z4 sDrive35is, and 335is, have used the N54HP, which is the old twin-turbo engine.) The N55HP uses the Valvetronic variable valve lift system for increased efficiency and, in this application, produces 315 hp (from 5800-6000 rpm) and 300 lb-ft of torque (1600-4500 rpm.)
Bolted to the sport version of the ZF eight-speed automatic transmission, the 4190-pound 640i has a first gear short enough to easily smoke the 275-section rear tires and a cruising gear long enough to achieve 30 mpg on the highway (or so BMW estimates). In manual mode, the transmission's shifts are quick and positive enough to rival the best dual-clutch gearboxes, and its torque converter makes off-the-line getaways smoother than any of them. A standard start/stop system helps fuel economy in city traffic (BMW is expecting 20 mpg on the EPA test) and is relatively unobtrusive.
The steering feels more heavily weighted than in the 5-series, but the electric motor mounted on the rack still absorbs most of the steering feel. Our tester's optional Integral Active Steer kills whatever feel is left in exchange for quicker turn-in, a smaller turning circle, and a superfast ratio at parking-lot speeds. As you'd expect, the remainder of the driving experience is highly reminiscent of the 535i, 640i coupe, and 740i with which the Gran Coupe shares its driveline components. That means a perfect driving position, class-leading refinement, excellent handling, and a suspension that does a superb job -- until it hits the bump stops.
Like the other BMWs that use this suspension design, the Gran Coupe rides great at first but then whomps over moderate bumps with slightly too much harshness. All hell breaks loose when you hit the big stuff -- you'll get an impact so harsh you'll think something broke. One highway-speed bump bottomed out the front-right suspension so hard it canceled the cruise control, prompting a message on the instrument panel that the feature would again become available when suitable road conditions returned. For the record, that bump was something that a Mercedes CLS or an Audi A7 would have taken in stride. In fact, most economy cars wouldn't have been seriously bothered by it.
In addition to the hard-as-lead bump stops, the M Sport Package's enormous twenty-inch wheels are likely to blame. They look great, but they're clearly too heavy for the suspension to manage, even with the 640i's standard adaptive dampers. Given our experience in a sport-package-equipped 535i, which suffered from harsh impacts that caused tire damage, we're not that surprised.
The Gran Coupe gets few other demerits: it uses the 640i coupe's seat-mounted seatbelts, which is strange because the B-pillars look thick enough to support an entire house. We suspect owners will get used to this in time, but the seatbelts would be far easier to reach if they were mounted to the pillars. The large glass sunroof tilts but doesn't slide, and when the shade is opened, sunlight glare renders the lower part of the gauge cluster partially illegible. Seeing out back would be a problem except the reverse camera is standard.
Those concerns aside, the 640i Gran Coupe's sumptuous interior makes up for all of it. We've been hoping that BMW would build this car ever since the 2007 CS concept, which previewed its exterior styling and its beautiful, leather-lined cabin. Plans to build the bigger-than-a-7-series CS were scrapped due to the global recession -- but its core concept was resurrected (in smaller form) here as the Gran Coupe. The delay means some of this car's styling has been seen before -- it would have been a more effective brand halo if it had come first. But that doesn't change the fact that the 640i Gran Coupe is a stunning example of how you can take a bunch of off-the-shelf parts, throw caution to the wind, and build a car that's better than any of the products it's based on.
BMW has already announced the 650i Gran Coupe, which uses the new Valvetronic-equipped version of the twin-turbo 4.4-liter V-8. That reverse-flow brute now makes 445 hp and 480 lb-ft of torque, and it'll send power either to the rear or all four wheels. The all-wheel-drive version will be the quicker of the two, getting to 60 mph in 4.3 seconds versus the tire-smoking rear-driver's 4.5. We call overkill -- the 640i feels far faster than its factory-certified 5.4-second 0-to-60-mph time would suggest, and its straight-six music is both aggressive and refined. If you want even more speed, may we suggest you wait for the M6 Gran Coupe. BMW hasn't confirmed it, but it's a no-brainer to build -- and we suspect it would be a better all-around performer than either the M5 or the M6. The idea of good, old-fashioned hydraulic steering (like the M5 and M6 still have) in a sedan with supercar performance and supermodel looks -- made of off-the-shelf parts? Now that's a Gran Idea.
On sale: Summer 2012
Base price: $76,895
Engine: 3.0L turbo I-6, 315 hp, 330 lb-ft
Transmission: 8-speed automatic
Fuel economy: 20/30 mpg (est.)