2dr Convertible (640i SE & M Sport, 650i SE, Sport & M Sport, 640d SE & M Sport, M6)
If every BMW is still to be the 'Ultimate Driving Machine' promised by the advertising, then that slogan must mean many things. Sharp, rewarding handling for most is what this brand is all about but in some market segments, other virtues are just as important. Take up-market large luxury convertibles. Specifically, used ones from the 2011-2018 era. Cars of this sort from this period like Mercedes' SL and Jaguar's XK are all about Grand Touring - fast, stylish cruising, something BMW has more experience in providing than you might expect, with a product heritage in such cars stretching all the way back to the 327 Sports Convertible of the late Thirties. And all the way forward to this car, the second generation 'F12'-series 6 Series Convertible, launched in 2011.
The previous 'E64'-series version of this car was a relatively rare sight on British roads - and not only because BMW imported limited numbers. Despite a hefty price tag, it offered performance, rear seat room and boot space all little better than a BMW 3 Series Convertible from the same era costing half as much. The 'E64' open-topped 'Six' was a car that sold on cachet - and that wasn't enough to tempt significant numbers of wealthy buyers from their Mercedes SLs and Jaguar XKs. This second generation model though, proved to be a different proposition. Seriously fast, significantly bigger and sensationally styled, it claimed at launch to be the car to beat in its segment and sold much better than its predecessor. BMW lightly updated the car in 2015 and continued to sell it until early 2018, when it was finally deleted from the company's line-up.
What You Get
This 'F12'-series car needed to be bigger, more dynamic and more expensive-looking than its predecessor. It is. Yet despite being 39mm wider and 74mm longer than the old model, designer Nader Faghihzadeh still managed to create a lithe, agile look apparently inspired by the feeling of surging through water. Imagine the movement of waves sent out by the bow of a powerful motorboat and you're supposed to be able to relate the impression to this model's harmoniously curved surfaces, from the long sweeping aluminium bonnet with its distinctive 'shark nose' through muscular wheel arches to the unique 'fins' that mark out the soft top.
Yes, it does have a soft top - which might come as a surprise given that the cheaper 3 Series Convertible from this era featured a more expensive folding metal hardtop arrangement. Using that here would have bloated the weight (already around two tonnes), belittled the luggage bay and probably added an ugly rear end, all that roof work having to sit somewhere. So like the Jaguar XK but unlike the Mercedes SL, this 6 Series Convertible has a fabric top, though to be fair, it is a very special one. Multi-layered, acoustically lined and thermally insulated, it's tailored to include special 'fins' which rather neatly, allow the upright, heated glass rear window to be lowered separately from the roof.
The roof is also very quick to operate, electrically retracting via a centre console button (or optionally via the keyfob) far quicker than any metal folding system could, in just 19s at speeds of up to 25mph, raising again in 24s if you find that the breeze is a little fresher than you thought, though the low down seating position which reduces buffeting makes this less likely. Cheaper convertibles help combat cooler roof-down conditions with 'airscarf'-type systems that channel warm air below the head restraints into your neck. There's none of that here. Nor do you get the kind of seat belt 'presenters' that hand you your buckle as you get in to save you reaching over your shoulder for it. And while we're nit-picking, rear visibility roof-up isn't great - but then, that's also an issue common to all this car's close rivals.
Still, these things apart, the gorgeous interior with its fastidious attention to detail is very difficult to fault and is especially nice if you find a car fitted with the expensive option of a leather finish for the instrument panel that dials the cabin ambiance up a few notches. The cabin design is based around what BMW calls a 'twin cockpit' approach, intended to feel like an upmarket powerboat. The dash is dominated by a large colour screen and the instruments are canted carefully towards the driver, though many of them are recognisable from the brand's cheaper models. To reduce button clutter, most of the functions and features are taken care of by the infamous iDrive system, here much easier to use than it once was, despite many functions and menus.
And behind? Well the seats in the back are restricted in size of course but they do benefit from this MK2 model's extra body length to the point where they're significantly bigger than those provided by rivals and perfectly comfortable for children and adults on short journeys. They could be easier to get into with the roof up though, despite an Easy Entry function which electrically slides them back and forward. The boot too, is decently sized for the class at 300 litres with the hood folded and 350 litres with it raised - that's 50% bigger than a Mercedes SL. BMW betrays the target market by letting on that this is enough to hold two golf bags.
What to Look For
Our owner survey did reveal many satisfied users of this car but inevitably, there were a few issues reported. Not, interestingly, with the electrically-powered roof - though check its functionality thoroughly. Issues tended to centre upon electrical and engineering problems. In one case, there was an engine management fault. And there've been some reports of faulty boot seals which have led to ingress of water into the boot - a problem because quite a few electric systems reside here. In some cases, the headlights on this 6-Series can be prone to condensation. This is a common problem on this car and if not treated can damage the wiring, meaning that a new headlight unit would be needed, which can be extremely expensive. To correct this, some owners resorted to drilling a small hole at the bottom of each headlight, so as to allow any water to flow out, this helping to prevent a condensation build up.
On the turbo diesel versions of this 6-Series, the turbo is prone to failure. There are 2 turbos on these cars and it is possible for any one of them to fail. Common symptoms of this failure are: a loud whistling noise coming from the top of the engine, lack of power when accelerating and/or black smoke coming from the exhaust. You will need to identify which turbo is faulty and fit a replacement one, in order to fix the issue. Otherwise, it's just the usual things. Insist on a fully stamped-up service record and check the alloys for scratches and scuffs.
[based on a 2015 model 640d diesel auto] Parts prices for a 6 Series Convertible can be reasonable if you shop around. We trawled around the internet and found these: An air filter costs around £19-£31. An oil filter is in the £10-£26 bracket. A fuel filter is in the £20-£29 bracket. Front brake discs cost in the £426 bracket. Rear brake discs cost in the £340 bracket. Front brake pads sit in the £61 bracket for a set. A set of rear pads is around £30-£48. Rear brake callipers are around £225. A radiator can be had for around £243.
On The Road
On the Road
At the end of a day spent in pursuit of the kind of business that makes possible the purchase of a car like this, you want to be rewarded on your route home. First, by the classiest possible cabin. And second by a gloriously emotive soundtrack when you fire the engine and nose out into the traffic. Both are delivered here, along with an alfresco driving experience free, as you would expect, from all the roof-down buffeting and body shake that you'd get in a cheaper convertible. Which means that you'll be tempted to lower the roof more of the time, especially as it can be done in just 19s at speeds of up to 25mph. Raising it again in 24s cocoons you in a cabin almost as refined as you'd find in the alternative Coupe and four-door Gran Cabrio models that BMW also offered during this period in the 6 Series range.
And of course, it's fast. Even in the least powerful 640i petrol model, you've a 320hp in-line six cylinder petrol unit capable of sixty from rest in just 5.7s on the way to a top speed that would be well into the lock-you-up-and-throw-away-the-key area of licence confiscation were it not for a limiter that cuts in a 155mph. The same kinds of figures are delivered with a lot more overtaking torque (up from 450 to 600Nm) by the diesel 640d variant, the twin-turbo six cylinder variant chosen by more than half of all 6 Series Convertible buyers.
Otherwise, provided you don't want to get into M Sport territory, your other option is the 4.4-litre 405bhp V8 provided by the 650i model that goes gunning for wealthier buyers who'd otherwise perhaps be looking at Mercedes SL500s, Jaguar XKRs or Maserati GranCabrios from this era. This engine's torquey too, with more than enough pulling power to make unnecessary as many as eight ratios in the Steptronic automatic gearbox, but BMW has provided them anyway, along with a set of paddle-shifters behind the steering wheel for when your favourite secondary road opens up and you can access performance that'll catapult you to 60 from rest in a Porsche-worrying 5.0s. The same V8 features in the top M6 derivative, which puts out up to 560hp and can demolish the 62mph sprint in just 4.3s.
Across the range, there's a standard Drive Dynamic Control system, which allows you to choose how responsive you want the gearbox, steering and throttle response to be. So if you want to push on, you can use the provided rocker switch by the gear lever to move from 'Normal' to 'Sport' mode. The throttle then sharpens, the steering tightens and the gearbox revs a little longer in each ratio. Not enough? Well, if you've a really challenging road ahead, a further prod on the rocker reveals a third 'Sport +' setting where things are sharper still and the stability and traction control systems allow more wheel slip for playful cornering. Many original owners also specified the extra cost Adaptive Drive package which adds an extra 'Comfort' mode to the rocker switch options, allowing you to adjust the dampers and anti-roll bars to create a really laid-back driving set-up for long distances. Or alternatively sharpen them up by selecting one of the controller's sportier modes. Dynamic Stability Control allows an amount of slip to the rear wheels. Dynamic Stability Control allows an amount of slip to the rear wheels.
After playing with all the settings, you'll discover that that there isn't one with a perfect all-encompassing ride/handling balance you can leave the car in all the time - but maybe that's not the point. BMW wants its drivers to be able to set this machine to their liking on any given day to any given preference. And to be fair, whatever mode you select, there are a few constants. One of them is well regulated body roll, courtesy of the fact that this car's underlying structure is 50% stiffer than its predecessor. Even so, you'll need to remember before throwing this car around that any 6 Series remains first and foremost a Grand Touring GT rather than a sportscar. Or, to put it another way if it makes more sense, more a Mercedes SL than a Porsche 911. The electric power steering is further evidence of this, with a lightness not designed for enthusiasts, though you'll find it a little sharper if the particular car you're trying was originally fitted with the optional direct variable ratio set-up that comes with the 'Integral Active Steering' set-up, a package which also included four-wheel steer for sharper cornering turn-in.