What is it?:
BMW says the new, second-generation M6 convertible is the fastest-accelerating open-top road car it has ever built. Which is a fair enough statement given that it hits 62mph from standstill in 4.3sec, rockets from 50-75mph in fourth gear in a rather special 3.8sec and runs the standing kilometre in 22.1sec – in each discipline outpacing the old M6 convertible, its previously fastest series production open-top.
It also reaches 189mph, according to the head of BMW’s M division, Friedrich Nitschke, when running an optional M Driver’s Package. Serious numbers, no less…
The remarkable thing is that the latest M-car manages all this while laboured with a kerb weight of 1980kg – a figure that places it firmly in the heavyweight class, some 185kg above that of perhaps its keenest open-top rival, the Jaguar XKR-S convertible.
But with a 552bhp twin-turbocharged 4.4-litre V8 petrol engine, the M6 convertible is claimed to possess colossal straight-line speed. Given its breathtaking £98,995 price tag – a good £10,000 more than its direct predecessor here in the UK – you could argue that it ought to be.
What's it like?:
Is the new open top BMW really as quick as the official performance claims make out? Initial impressions suggest it is; with 52bhp and 118lb ft more than the old model’s naturally aspirated 5.0-litre V10 it is terrifically potent.
It’s not the sort of car that screams for attention – M-cars rarely have. But the styling changes give it a more menacing air. Included is a deeper front bumper with larger engine cooling ducts, a 30mm increase in the front track, BMW M division’s signature chrome gills and a new rear bumper with an integrated diffuser.
The cabin of any M car should be special. The steering wheel, instruments, gear lever and the front seats are unique to the M6. The most important functions, those that allow you to alter the driveline and chassis characteristics, are grouped together around the gear lever. Not so clever is the positioning of the switch for the fully automatic fabric roof, which sits where your elbow rests on the centre console.
On the open road, the M6 convertible’s forced induction engine possesses an alluring range of sounds. Under load the V8 emits a deep mechanical growl accompanied by a high pitched exhaust note – which grows in volume and intensity was the revs built. The constant pops and crackles on downshifts are equally compelling.
As well as providing the necessary muscle for the M6 convertible, new engine also endows it with relaxed cruising properties. The vast reserves of turbocharged induced torque ensures flexibility from not far beyond idle speed, removing the need to flick through the gearbox.
The first ill fitting drain cover dispenses any lingering doubts about the M6 convertible’s structural rigidity. It was conceived at the same time as the M6 coupe and incorporates the necessary floorpan strengthening enhancements to ensure scuttle shake is never a major factor.
Roof-up refinement is exemplary by soft top standards. At motorway speeds there is little buffeting and, provided you’ve dialled up a tall gear, the otherwise frenetic exhaust note is conspicuous only by its absence. The fabric roof folds and stows in the top section of the boot at speeds up to 25mph within 19sec.
The M6 chassis set-up is skewed more towards everyday use than outright performance. The variable control damping is predictably firm to provide the best possible body control. The springs are sufficiently compliant to endow it with a cosseting feel in comfort mode. It is certainly a big improvement on the old M6 convertible. This new found comfort bodes well for the M6 convertible in the UK.
Less so the steering, which possess a vague feel in the initial quarter turn of lock. Perhaps it is a result of the cabriolet's less rigid structure, but the hydraulic-operated system never feels quite as sharp nor gives the impression of being as responsive as the same set-up used in the M5.
Accept the disappointment of the pensive turn-in and you discover the M6 convertible is quite capable of delivering the sort of driving excitement expected of a car wearing the revered M badge. It takes some time to find it, though, thanks to myriad of variable chassis settings allowing you to alter the mapping characterstics of the steering, throttle gearbox, damping and stability control characteristics.
Grip levels are massive, allowing you to carry enormous speeds through faster corners without any premature breakaway. In slower corners the negative scrub radius brought to the front end provides an initial touch of understeer, but with the most liberal of driving modes (MDM or M drive mode) dialled up the operation of the DSC (dynamic stability control) system is sufficiently delayed to allow a whiff of oversteer before the onset of the electronic safety net.
Should I buy one?:
The M6 convertible is an enormously impressive piece of engineering. It is quick - blindingly so in the right conditions. But at the same time it delivers the sort of relaxed cruising traits to make it a excellent every day proposition. It is also terrifically surefooted for an open top car, with dependable handling traits that urge you to explore its performance potential when the opportunity arises.
The breadth of its dynamic abilities is at the root of its appeal. It is also superbly finished, with a high quality interior that puts some open rivals to shame. However, it lacks the sort of back road delicacy we’ve come to expect from cars conceived, designed and produced by the German car maker’s highly respected performance car off-shoot.
BMW M6 convertible
Price: £98,995; Top speed: 179mph; 0-62mph: 4.3sec; Economy: 27.4mpg; Co2: 239g/km; Kerb weight: 1980kg; Engine: V8, 4395cc, twin-turbo, petrol; Installation: Front, longitudinal, RWD; Power: 552bhp at 6000rpm; Torque: 502lb ft at 1500rpm; Gearbox: 7-spd dual-clutch auto