We like
Does almost everything well, sumptuous interior, excellent multimedia system, performance and handling in Sport mode

Room for improvement
Annoying sports exhaust, driver’s seat could go lower, poor forward visibility, flimsy and fiddly wind deflector

Price and equipment

The price of $193,900 plus on-road costs for our Melbourne Red 640i Convertible was supplemented by a $2800 cosmetic upgrade comprising a gloss black shadow line running from the A-pillar, below the side windows and around the base of the rood and two-tone Nappa leather upholstery.

Another $2700 was spent on 20-inch multi-spoke black and silver alloy wheels, the piano black interior trim was $1000, dynamic damper control cost $2650, electrically adjustable ‘comfort’ front seats added $1600, ceramic control surrounds commanded $1100 and the premium Harman Kardon surround sound system seemed a relative pinch at $1600.

Other than the options, the 640i makes for a pretty well-specified entry point to the 6 Series Convertible range with a full suite of visibility aids including reversing camera, a top-down surround view and lenses in the front bumper to help when pulling out of parking spaces or junctions.

Further driver aids include a head-up display, lane-keeping assistance, blind-spot monitor, adaptive cruise control, automatic parking, front and rear parking sensors, high-beam assist, rain-sensing wipers, automatic adaptive LED headlights and LED fog-lights.

Soft-close doors, heated seats, dual-zone climate control, contrast stitching and leather trim for almost everything add to the luxurious feel.

A combination of BMW’s iDrive system, the multi-function steering wheel and voice control provide access to a 10.2-inch monitor with sat-nav, DAB+ digital radio, Bluetooth audio streaming, in-car internet/apps/concierge/traffic updates and much more.

The soft-top is fully automatic and comes with a wind deflector. BMW Australia also throws in a sports exhaust system.

Being a European luxury brand, BMW offers many options and customisations for the 640i, from a $60 smoker’s pack or $500 heated steering wheel to the $9500 Pure Metal Silver paintwork or a $16,000 Bang & Olufsen hi-fi pumping 1000W through 12 illuminated aluminium speakers.

Interior

It takes the most searching of fingers to find any cheap, hard plastics in the 640i interior, which is dominated by supple, contrast-stitched leather – even the sun-visors are upholstered in hide.

Non-leather surfaces are either soft-touch or have classy high-gloss finishes.

We were impressed by the plushness of the optional ivory Nappa leather on our test vehicle, which contrasted nicely with the black with white stitching applied to upper areas like the door caps and dashboard.

The cabin design is cohesive, with no single dominating feature, and it feels every bit the $200,000 car as a result. At the same time, the layout is unmistakably BMW and therefore logical, practical and user-friendly.

Our car’s optional comfort seats with electric adjustment (standard seats are powered too) move in almost every way imaginable but we felt a more ideal driving position could have been achieved if it went lower than it did. The adjustable thigh support was heaven-sent though, and we remained comfortable after hours behind the wheel.

Both the iDrive system and digital instrument panel were the paragon of clarity, with impressive and attractive hi-res graphics. The head-up display was also a boon, providing entertainment info, sat-nav directions, warning icons and more in additional to the speed readout.

Unlike some multimedia setups the iDrive was quick and responsive, with accurate voice recognition and beautifully detailed map graphics in the navigation mode’s 3D view. Pairing a phone via Bluetooth was a cinch, as was accessing music streaming services from the same device.

On the move and with the canvas roof up, we were impressed by the cabin’s quietness. The main intrusion is tyre noise from the rear but even at motorway speeds the air-conditioning fan was the most audible sound.

With the roof down, conversations can be had at normal volume provided there is not too much external traffic noise. Roof down, windows up and wind-deflector in place makes for a serene but sensual driving experience. Shame the flimsy-feeling deflector is a fiddle to fit and threatens to damage the leather surrounding its fixing points. On first use we did not trust it to stay in place at speed, but it did.

Narrow, shallow door bins and a rather small, divided glovebox were storage let-downs but the twin cupholders and large centre console bin beneath the central armrest made up for it. There are always the occasional rear seats and map pockets if more cabin storage is required.

On the subject of rear seats, the individual buckets are comfortable and roomy enough for shorter adults provided those in the front are not tall. Those slim and agile enough to get in with the front seats tilted are lucky but others have a long wait as the electric adjuster takes its time to move them out of the way.

With the roof up, there is plenty of headroom in the front and it is adequate in the back given the limited legroom for taller passengers.

The pillarless design means side and over-the-shoulder visibility are great – especially with the roof down – but the thick pillars of the steeply raked, low windscreen limits forward visibility (we lost a whole hatchback in the driver’s side A-pillar while the interior mirror causes another blind-spot) and the flying buttress design of the roof makes rear quarter vision difficult.

As a result we were grateful for the plethora of standard cameras, parking assistance and sensors but we still had to take extra care around pedestrians and cyclists in urban areas.

We felt the blind-spot assistance was hampered by the location of the illuminated warning triangles, which are on the inner mirror casing rather than in the glass. The illumination was hard to see in daylight and the viewing angle on the driver’s side is not ideal.

A significant amount of boot is given to roof stowage but the shallow remaining space is wide and long enough to provide more than 300 litres of volume. As the 640i has run-flat tyres, only a small tool roll and battery system are located beneath the boot floor.

Engine and transmission

Within the long, low snout of the 640i lurks a 3.0-litre turbocharged straight-six, pumping out 235kW between 5800 and 6000rpm. Peak torque of 450Nm is available from 1300 to 4500rpm.

Despite having to shift a portly 1820kg, it provides plenty of punch when pushed and a searing mid-range for confident overtaking or brisk acceleration out of corners.

The official 0-100km/h time of 5.5 seconds sounds about right but once up and running this is by no means a slow car. For Australian road use, the V8 650i would feel like a decadence by comparison.

In one of the two Comfort driving modes, throttle response is calibrated for smooth chauffeur-like driving, which initially felt doughy and sluggish but suits the car’s easy-going nature. Eco Pro mode takes this even further, but more on that later.

A much sharper feel is available from either of the Sport modes. It also opens a valve in the (standard for Australia) sports exhaust, which drones annoyingly at low speeds, howls intoxicatingly under load at high RPM, gurgles on full-throttle up-changes and crackles on the overrun. The start-up idle has a purposeful, sports-bike rasp too.

But in Comfort or Eco Pro modes the exhaust automatically opens and closes the valve, with artificial-sounding results and the aforementioned annoying – and embarrassing – drone accompanies even moderate throttle inputs like accelerating away from traffic lights or hill-starts.

Were it our money, this would be enough to make us ask the BMW dealership to specify a standard exhaust.

As with throttle response, the character of the eight-speed automatic transmission is dramatically altered between Comfort and Sport modes.

In the former it is smooth, discrete and slurs changes, while the latter brings lighting-fast cog-swaps – automatically or manually using the paddle-shifters – and a habit of holding onto each ratio for longer to complement the sharper throttle response.

Drivetrain characteristics are not compromised in Sport mode, making it more than usable for low-speed, urban driving and the recalibration reveals a much more dynamic side to the 640’s otherwise grand touring nature, bringing the car alive.

Eco Pro mode sets the transmission to upshift early and ride the wave of turbocharged torque while further numbing throttle inputs and allowing the 640i to coast off-throttle. It also changes the tachometer to a more EV-like charge/power display and clocks up the additional kilometres of fuel tank range gained as a result of selecting Eco Pro.

We found driving the 640i sedately on a twisty country road frustrating in Comfort or Eco Pro modes, the dulled throttle response sometimes causing the turbo to kick in unpredictably mid-corner. The extra control of Sport mode made smoother country road progress easier to achieve.

Fuel consumption during our week of mostly top-down driving on urban, suburban and country roads plus a couple of motorway stints was 11.7 litres per 100 kilometres, significantly higher than the official 7.9L/100km combined figure – one we didn’t even achieve on a roof-up motorway cruise. But we were happy when we found it took 95 and not the expected 98 RON Premium Unleaded.

Ride and handling

If it seemed as though we went on about the different driving modes in the Engine and Transmission section it was due to the Jekyll-and-Hyde nature of the calibration differences, which apply equally if not mores to the 640’s dynamic characteristics when fitted with our car’s optional dynamic damper control.

In the default Comfort mode, the 640i is a consummate grand tourer and feels as though it would happily waft its occupants through a 2000km road-trip in complete luxury and control. The steering is light and smooth, the ride supple and the refinement impressive.

Road imperfections only affecting one wheel or perhaps one side of the car result in some chassis shudder and the rear suspension seems to slam across bumps more than the front, while the suspension and chassis seem to store up ripples or patchwork surfaces rather than casing them off, sending reverberations around the body.

We can live with these occasional foibles, no doubt symptoms of the missing structural roof, in exchange for the pleasures of open-top motoring.

The ride only gets slightly more nuggety in Sport mode but the steering comes alive. Around the centre it remains calm but tip the 640 into a corner and the extra bite in how it loads up is instantly recognisable after the insulated feel of Comfort mode.

What little body roll Comfort mode permits is all but eliminated, the chassis and steering communicating in harmony to tell the driver exactly how hard they can push the nose into corners – and the answer is alarmingly quickly.

There is heaps of grip but the 640 feels alive enough at legal speeds to provide plenty of satisfaction for the keen driver. Despite the warnings about reduced stability control in Sport+ mode, we found this setting just right for a back-road blast as the nannies felt a little too intrusive in standard Sport mode.

Interestingly, Sport+ will still keep the driver nice and tidy but seems intelligent enough to know when deliberate liberties are being taken and take a step back from the action while keeping a firm hand on the digital safety net.

The powerful brakes and their fantastic pedal feel add to the confidence – and smile – that builds with every twist in the road.

After days of wafting around and concluding that the 640i nails its brief as a luxury open-top grand tourer, we were surprised and delighted after hitting our favourite serpentine stretch of Sunshine Coast blacktop in Sport and Sport+ modes.

It revealed a totally different and utterly enthralling side of the car’s character that begs to be explored once discovered.

Safety and servicing

NEITHER ANCAP or Euro NCAP have rated the BMW 6 Series.

Standard safety equipment on the 640i Convertible includes front and side airbags for the driver and front passenger, electronic stability control, traction control, anti-lock brakes with cornering brake control and dynamic brake control.

As mentioned above, there is also adaptive cruise control, lane-keeping assistance, blind-spot monitoring and a raft of cameras and sensors to help with manoeuvring in tight spaces.

Being a modern BMW, the 640i sets its own service schedule depending on how it is driven, and BMW Australia includes basic servicing for the first three years and roadside assistance for seven years in the price of each new 6 Series, transferrable to future owners.

The standard warranty is three years and unlimited kilometres including paintwork, plus 12 years’ bodywork cover.

Verdict

Every journey in a $200,000 car should feel like an occasion, but you would be surprised at how many we encounter in this job that do not. The BMW 640i Convertible however, does make every outing feel special, roof up or down.

And that’s not just because the model is so rare on Australian roads.

Something that kept going through our minds as we drove the 640 was that its relaxed, grand touring nature reminded us of a Jaguar. Then we’d look at the long, sleek bonnet and overall proportions of the car and find more parallels with the Big Cat brand. We mean that very much as a compliment.

But the excellent interior that demonstrates a rare harmony of high technology with traditional luxury and the excellent dynamic package unlocked by selecting Sport+ mode reveal an impressive depth of engineering achieved by few.

That the 640i Convertible offers such distinct personalities at the touch of a button, with the extra dimensions of roof-optional driving and just-about-usable rear seats, make for a compelling package.

Most of its flaws are forgivable compromises to versatility or annoyances that would probably fade with familiarity. We must remind ourselves that no car is perfect.

But if a car can be judged by how much it makes you smile or want to go for a drive just for the sake of it, the 640i Convertible is a perfect 10.

Rivals

Porsche 911 Carrera Cabriolet from $239,300 plus on-road costs
The price above is for the facelifted and newly turbocharged version we had not driven at the time of publication. Compared with the front-engined 6 Series the rear-engined 911 is sportscar first, grand tourer second. It costs more and is less lavishly equipped but the Porsche badge has arguably more cachet than BMW.

Meanwhile the conceptually similar Aston Martin DB9 Volante, Bentley Continental GTC and Maserati GranCabrio are the next nearest thing to the 640i Convertible and all cost significantly more.