BMW usually launches the coupe version of a new model before the convertible. Not this time. The new 6-series convertible will arrive first so that it can enter BMW's two largest markets – the U.S. and Europe – in the spring. Coupe buyers will have to wait another six months.
Not that BMW is relying solely on seasonal weather to generate showroom traffic. It has also given its new open-top a heady dash of style as part of a complete re-engineering job that brings a new rear-wheel-drive platform (based on the 5-series) more contemporary engines featuring EfficientDynamics developments and a whole host of electronic chassis aids.
Gone is the bullish, bloated look of the old model, replaced by a more elegant and cohesive design. It's also slightly longer (by a shade under 3in.) wider (by 1.5in.) and lower (by a scant 0.32in.)
The interior has been reworked thoroughly, too, with a unique dashboard, classier materials and extra attention to detail. It's a great place to be and the low-set driving position gives the car a proper sporting air that's removed from the more upright seating position of a 5-series.
The increased dimensions provide front seat occupants with plenty of room, but the individual rear seats lack legroom and are not at all easy to climb into with the roof up.
There are two engines available: The base 640i convertible gets a 3.0-liter turbocharged inline-six good for 320hp. The 650i has a 4.4-liter V8 rated at 407hp and 443lb-ft of torque.
The 650i's V8 ($91,375 MSRP) delivers truly heady performance and extraordinary levels of refinement. On light to moderate throttle loads, even with the roof down, there is an almost complete lack of mechanical intrusion in the cabin, making the new BMW a serene boulevard cruiser. Roof up, the heavily insulated top ensures it's extraordinarily quiet and well sealed.
All that torque at just 1,750rpm and the speed of BMW's latest 8-speed automatic gearbox make light work of the 650i's excessive 4,277-lb curb weight. The car dispatches 0-62mph in just 5.0sec and has the sort of full-throttle in-gear acceleration to make the outgoing 5.0-liter V10 M6 convertible seem off the pace.
On the open road, however, the new 6-series convertible – 50 percent stiffer than before, says BMW – feels terrifically solid, with very little scuttle shake, even over nasty ruts. And, crucially, it's a good deal more entertaining than its predecessor. It changes direction with added eagerness and can be relied on to adjust its line mid-corner.
As for driving characteristics, it really depends on which chassis setting you choose. BMW's Dynamic Drive system puts three modes at your disposal – Comfort, Normal and Sport. An additional setting, Sport Plus, also delays the intervention of the stability and traction control systems to give you a further dimension.
Normal is the mode of choice for everyday running, providing an excellent blend of ride quality, body control and overall response. It better suits the car's athletic character than Comfort mode, which unnecessarily softens up the suspension, introduces added body roll and takes the sharpness out of the steering. For more spirited driving, Sport mode is definitely the way to go, providing the sort of agility usually associated with a much lighter and more focused performance car.
The new 6-series convertible is clearly a more complete car than the one it replaces, with its more elegant styling, improved cabin quality, increased performance potential, reduced fuel consumption (26.4mpg combined for the V8) and more entertaining on-road qualities. It's a positive step forward and a much more worthy rival to the likes of the Jaguar XK cabriolet and Mercedes E-class coupe.
Greg Kable/Autocar