2007 BMW M6 Review

Specifications

Open-Topped Autobahn Bruiser

The Germans have always been very, very good at building ruthlessly quick cars. From the first Auto Union racers to the current crop of uber-cars from Audis, Mercedes, and BMWs respective tuner lines, theyve gained a reputation for manufacturing extremely fast yet reliable cars that exude engineering excellence. BMWs M branch is at the fore of that reputation, known for building the class dominating M3 sports coupe, and what has long been recognized as the ultimate sports sedan; the M5.
But they also produce a number of additional M cars, hardly the least of which is the M6. Based on the 6-Series but endowed with the M5s furious 500 horsepower V10, the M6 hasnt garnered as much press as its less shapely M-cousins for the simple fact that its up against stiffer competition and therefore doesnt rate as highly. Comparatively, while the M5 goes up against (and beats) the Audi S6 and Mercedes Benz E55, the M6 must contend with slightly more challenging competition, such as the Corvette Z06, Mercedes Benz SL55, Aston Martin V8 Vantage, and most importantly, the Porsche 911 Turbo. In numerous comparisons the M6 powertrain impresses its testers, but the heavy cars softer nature and too-technical nature has led many critics to proclaim it an uber-fast GT rather than an out and out sports car. So, if youre BMW, what do you do?

Well, you could fight back. Trim even more out of the 6-series carcass (although theyve already gone pretty far with the M6 coupes carbon fiber roof), firm up the suspension until its drumhead tight, and remove as many of the electronic wizards and nannies as you can bear to lose in what would probably be a vain attempt to dethrone the Porsche 911; or you can succumb to the fact that you built what could be considered one of the ultimate super-sporting GT cars.

Suffice it to say, they succumbed. For if they were fighting the sports car battle, theyd never have introduced this dashing lad to their lineup: the M6 Cabriolet. Designed to offer the same draw as the M6 coupe albeit in a more spiritual open-top configuration, the convertible is a point of pride with the Teutonic Bavarian brand. Aiming for the same comfort level as any hard-top convertible, BMW began with a rubberized out layer, then opted to line it with polyurethane foam that provides greater sound deadening capabilities than the standard fleece lining. Next, they incorporated a flying buttress look into the rear pillars, and while the press release uses terms like “innovative” to define the look, its reminiscent of the old Jaguar XJS, with its similar vertical back glass. Of course, while the XJS coupes buttresses and back glass were strictly styling cues, the BMWs shape is necessitated by the sloping roofline that would have required a massive piece of glass to form the back window, much like that found on coupe. So instead of trying to package such a bulky piece of glass or replacing it with low-rent plastic, BMWs engineers instead opted to make a retractable vertical back window that, when the top is up, serves as another way of getting fresh air into the cabin. And of course, since its glass, the back window also has a defroster built in for those cold winter mornings, plus youll never have to worry about it fading and cracking like you would a plastic window.

Beyond the top, the rest of the cabriolets body is pure M6, with the same flame-surfaced style thats garnered so much attention. Love it or hate it, the curvy, organic style is certainly noticeable, and in the M6s case, very slippery, having been designed with extensive time spent in the wind tunnel, perfecting the airflow over the body.

The low front air dam directs as much air as possible at the radiator, while the “flaps,” or small spoiler lips on the front air dam, serve to reduce lift over the front axle, keeping the huge front tires in contact with the ground. Even the side view mirrors were designed with airflow in mind, and are actually downforce-producing elements. Out back an air dam accounts for the M6s 2-inch longer overall length as compared to a regular 6-series. While it does decrease lift over the back axle, it also extends the car in profile while widely flared wheel arches make it appear wide. Without a roof, the M6 cabriolet looks even longer, lower, and wider than the already imposing coupe form. A small spoiler sits on the trunk lid, and the light units encased in the bumpers are moved upwards slightly to smooth out the airflow over them.

Additionally, when designing the cabriolet, BMWs engineers went back to the wind tunnel to design an effective wind deflector that can be raised to decrease airflow within the cockpit and make open air motoring a more enjoyable experience. Buyers also have the option of painting their M6 any regular 6-Series color, or rather choosing from five M-specific hues.

Inside, the M6 cabriolet sports the same comfortable interior as the M6 coupe with the only difference being that the cabriolet benefits from unlimited amounts of headroom. That means the cabriolet gets all the same soft leather surfaces the regular M6 gets, and BMW assures us the leather should have no trouble handling the elements, should it start to sprinkle before you put the top up (which, coincidentally, takes 25 seconds and can be done at speeds of up to 20 mph).

Buyers will choose from three standard leather colors; Black, Silverstone, and Sepang, while the roof may be ordered in Black or Basalt Grey on the outside, with the only headliner option being black; most likely thanks to the unique polyurethane foam. Opting for an enhanced leather option will allow buyers to add Indianapolis Red and Portland Natural Brown (we sense theres a theme in those color names) to their palette of selectable leathers, and will extend the leather coverage to include the instrument panel, A-pillars, upper windscreen panel, and even the upper roof locks (the standard leather interior covers the seats, steering wheel, center console, handbrake lever,  sun visors, door and rear side panels, and armrests).

The driver is the focus as in any BMW, and as such is faced with a plethora of switches and readouts. Most of the features the driver may need to access at any point on any journey are mounted on the steering wheel, and the result is one cluttered wheel. Those features not available via a steering wheel-mounted button can be accessed through BMWs infamous iDrive, meaning youre probably better off just making do without the feature in question, at least until you pull over to twist, pull, push, and click the selector knob at leisure. Thankfully, the instrument panel is blessedly simple, with the chrome-ringed tach and speedo flanking a few traditional sports car gauges as well as the sequential manual gearboxes current cog. Selecting the optional head up display projects all that relevant information on the windscreen, with the M6s HUD possessing both a standard readout and an M readout that emphasizes engine speed and offers an F1-inspired shift line informing the driver of the best time to shift for maximum thrust.

But of course the real gem of this uber-GT is the V10. Displacing 5 liters and lifted from the M5, the M6s powerful motor owes its layout and design to the most advanced race series in the world: F1. With 507 horsepower and 383 lb-ft, the V10 thrives on high engine speeds. At 8,000 rpm, 250 rpm below the redline, each of the motors pistons is traveling an astonishing 66 feet per second; about half the piston speed of an F1 engine. But that doesnt mean it cant perform on the low end of the rev spectrum; over 80 percent of the available torque comes on tap at only 3,500 rpm, which, when combined with the drivetrains relatively short gearing, catapults the M6 from standstill to 60 miles per hour in 4.7 seconds. Even more impressive, tapping the high-rpm horsepower during the jaunt from 50 to 75 mph in fourth gear takes only 4.7 seconds.

A big part of those impressive numbers is the SMG transmission. With seven forward gears, the clutched manumatic offers the what some consider an ideal balance of sportiness and comfort. With paddles behind the wheel and a stubby shift lever on the console, a driver can feel like Jacques Villeneuve thanks to perfect upshifts and exacting downshifts with every flick of the fingers, complete with throttle blips. Should you want to let the transmission take over, 5 of the available 11 Drivelogic system settings (the remaining six affect shift parameters when in manual-shifting only S-mode) will determine how hard, fast, and when the transmission shifts, ranging from performance-oriented lightning quick shifts to soft and comfortable low-rpm changes more suited to Sunday morning cruises. Due to some peoples complaints of the SMG gearbox, mind you, BMW is expected to drop a six-speed manual in all M6 models, as well as the M5, next year. Stay tuned.

Like the M5 and M6 coupe, the cabriolet also benefits from the very nifty launch control program that takes all the guesswork out of accelerating quickly: simply hit the “M” button to access the full 507 horsepower, turn off the Dynamic Stability Control, select the most aggressive manual shift program, hold the selector lever forward, bury the throttle, and release the lever. The engine will automatically hold the exact revs needed for the best launch possible until the lever is released, at which point everything will surely become a blur.

So, while the M6 Cabriolet isnt mechanically different from the M6 Coupe, we suspect the experience the open-topped version provides will be vastly different. With an exhilarating exhaust note sure to become even more audible with the top down, and the M6s already squat styling being enhanced by the lack of a roof, the cabriolet should be a surefire hit with those wanting to go fast and have the wind in their hair, but dont feel like making the sacrifices a dedicated sports car demands. Its amazing V10 and assortment of technological wonders will appeal to those who value perfection in engineering, but it faces stiff competition from the freshly redesigned Mercedes SL55 and the in-development Aston Martin V8 Volante (V8 Vantage convertible), both of which are impressive machines.