2014 BMW M6 Cabriolet: Heavy Artillery

BMW is unwavering when it comes to broadening and updating the lineup of its famous Motorsport GmbH performance division, whose creations are known simply by the prefix M. The most recent batch includes the third generation of the M6, which caps off the freshly remodeled 6 Series.

The M6 Cabriolet was the first to arrive last year, followed by the M6 Coupe. Both are now joined by the M6 Gran Coupe, an entirely original version for 2014. All three are powered by the same 4.4-litre twin-turbo V8 engine first seen in the M5 supersedan and the M versions of the formidable X5 and X6. This 560-horsepower engine makes the 6 Series cars the most powerful and sportiest to date, with a lot of luxury and style.

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With vertical black slats running across the nostrils of its front grille, the small M6 logo affixed to one nostril’s right corner, and the enormous air intakes decorated with matte black honeycomb grilles, the M6 Cabriolet is easy to recognize. The oversize fenders that cover the M6’s large tires and its wider (by 3 cm) tracks are made of moulded thermoplastic. They are fastened to the front by a pair of chrome air intakes used exclusively for M models.

The doors and hood are aluminum, while the lids for the trunk and roof storage are moulded fibreglass. The top, in your choice of black or beige, retracts in about twenty seconds up to 40 km/h. Its narrow glass window can be lowered separately if you need a more air. With the big blind spots that the top creates, the factory-standard front and rear Park Distance Control and the Rear View Camera are musts. BMW also fitted its new large convertible with aluminum roll bars that are deployed when the sensors detect that the car is starting to overturn.

Bathed in luxury

In keeping with its place at the top of the Motorsport hierarchy, the M6 Cabriolet’s cabin screams both opulence and performance. Its dashboard is designed like that of the 5, 6 and 7 Series, but the execution and materials are much richer and more stylish. The dash and console that combine leather and carbon fibre in addition to a hefty, rimmed sport steering wheel – also leather-covered – set the tone, with an assist from the large, flat, aluminum foot rest.

The new Motorsport seats are nicely sculpted and enswathed in particularly thick leather. Their multiple settings can be memorized with those of the lumbar support and exterior mirrors. A cushion that helps adjust the leg support is adjusted by hand. For the ultimate in pampering, opt for full merino leather upholstery for $5,900. The alcantara suede roof lining costs $2,500 and wood trim in red brown dark sycamore, oak, piano black or white ash add $1,000 to the bill .

The instrument cluster, directly in front of the driver, houses four classic round gauges. A small screen between the large dials in the centre displays the gear selected and the additional data you have chosen. Even improved, the iDrive interface with its large and oft-copied scroll wheel, is still rough at times, but the clarity and sharpness of the 10.2-inch screen partly make up for it.

The two programmable M Drive buttons mounted on the left spoke of the steering wheel are truly fantastic. Each helps the pilot record a combination of settings for the automated transmission and the variable speed and resistance steering, in addition to the electronically-adjustable dampers. You choose between Comfort, Sport and Sport + settings. The M buttons help you choose the Dynamic Stability Control (DSC) settings and the various display screens of the multicolour data on the windshield.

Powerful engine for an agile colossus

The 4.4-litre V8 with direct injection features a pair of DOHC turbochargers that are located between two rows of cylinders with the catalytic converters. This innovative concept of “reverse flow” reduces both turbo reaction time and harmful emissions from a cold start. This beast, codename S63Tü, produces 560 horsepower at 5,750 rpm and 500 lbs-ft of torque at only 1,500 rpm, which makes it the most powerful engine in a BMW production car thus far.

All that muscle is transmitted to the big rear tires by a seven-speed dual-clutch automated gearbox or a six-speed manual. The new M6 is supposed to go from 0-100 km/hr in 4.3 seconds with the Launch Control that comes with the Cabriolet, while the M6 Coupe and the Grand Coupe would do it in 4.2 seconds. Note that, at 2,048 kilos, the M6 Cabriolet outweighs the two others by 120 and 39 kg, respectively.

It’s also 50 kg heavier than the previous version, in spite of the lightweight materials used. However, it should consume 23% less fuel thanks to the new Valvetronic variable valve lift system and continuously variable valve timing in addition to other tricks such as kinetic brake energy regeneration and Auto Start Stop.

This much is certain: the magicians at the Motorsport Division had to use every trick in the book to squeeze every last drop of comfort, performance and handling from a car that weighs in at more than two metric tonnes. Grip was an absolute necessity and the M6 Cabriolet has that in spades with its front (size 265/35 ZR20) and rear (size 295/30 ZR20) tires whose excess zeal is tempered by an electronic limited slip differential. The supports that hold the suspension components are also bolted directly to the body, like in a race car, for enhanced precision.

Braking is already powerful with factory-standard 400- and 396-mm steel discs, but the new M6 is the first M model that can be equipped with carbon ceramic brakes, a $6,750 option. They’re 20 kg lighter overall and they never lose their efficiency. The front discs measure 409 mm.

Split personality

The M6 Cabriolet has been compared to a big, lazy cat when the driving systems are in Comfort mode. Accelerator reactions are lulled to the point of being almost soft. It gets high marks for the silence that reigns on board when the top is up and you’ll hear little more than the rustling of the wind on the highway. With the top down, the turbulence is minimal even if all the windows, including the rear window, are up. The ride is firm, as you’d expect, but it’s tolerable thanks to the front seats that positively hug the occupants. The back seats, if you can call them that, are forgettable, unless you’re willing to sacrifice a good part of the space in front.

The M6 convertible won’t transform from Jekyll into Hyde when you go from Comfort to Sport mode, but the changes are quite noticeable nonetheless. While everything becomes firmer in Sport mode, Sport + is for driving on a circuit or for intense driving on a really winding – and deserted – road. Pushed to the limit, even briefly, the M6 is simply amazing.

The sound of its V8 goes from a dull and strangely husky roar to a ferocious howl when the rev-counter needle reaches its 7,200-rpm limit. Shifting is instantaneous with the wheel-mounted shifters in Sport + mode and it pins you to your seat in a heartbeat. The M6 absolutely devours turns like an ogre, at any speed, but the rather heavy and very fast (the gear reduction ratio is 13:1) isn’t terribly communicative. You’ll have to drive it on a track to really get to know its true limits intimately.

Slim and muscular, the M6 Cabriolet is a treat for lovers of fine cars: a combination of luxury, style and performance. Solid and carefully put together, the simple touch of a few buttons and two or three pedals is enough to thrill you. Imagine how impressive it would be if it weighed a few hundred kilos less! For now, this M6 is, at best, a convertible GT, not a true sports car.