It's the season for convertibles to go into hibernation. While it is summer in Europe and drivers are going top down, unfortunately we have to contend with putting our cars through water-wadding tests on our roads.

But, there I was sitting inside the new BMW 650i, arguably one of the sexiest new four-seater convertibles there is, and sulking about the clouds letting loose their load. With the fabric-top roof up, the rising crescendo of the rain beating down was drowning out the peppy ABBA number that was belting out of the radio. I was in Mumbai to test drive the 650i and was yo-yoing between despair and joy, experiencing open wet roads and gingerly crossing flooded streets in the new car.

Mumbai during the rains can be fun, but can also quickly become messy. It hadn't gotten messy yet. Thankfully, the second day was bright and sunny for the most part and I managed to fully exploit the conditions.

In a manner of speaking, though, the 650i was in its element – water – after all, BMW's punchline for the car is ‘Inspiration Flows'. The new 650i is part of a modification and refresh program for the 6 series done a few years ago. Endowed with a new 4.4-litre V8 engine, the 650i has redefined the performance levels for a car in this segment and has become more of a driver's car than ever before.

The 2011 model year changes to the 6 series coupe and convertible has carried forward the overall squat, shark-nosed design of the predecessor. There are far fewer design flourishes, in the 650i. The design is now more simplistic, yet, there is a certain agility and flowy-ness. The new design also seems to give the 6 series convertible a tauter, sportier proportion.

Styling the curves

There is a lot of interplay between surfaces and (what BMW calls) power lines, which manages to take the monotony out of what could potentially be a rather boring, overall flat four-seater convertible design. The 650i's design also manages an interesting duality with the convertible's waistline providing a cocoon effect when it is in top-down mode and at the same time merging with the fabric fin-roof giving it a distinct coupe-like profile when the roof is extended and closed.

Bi-xenon headlights, the trademark kidney grille positioned low and slightly forward to flow with the shark-nose profile, the LED fog lamps and the signature LED rings of the daytime running lights are other highlights of the exterior design. The roof retracts and folds neatly into the rear or opens out and locks into the front A-pillar at the touch of a button in about 20-odd seconds.

A peek inside

Inside the new 650i, the cabin sports a young and inviting ambience. A lot of inspiration seems to have flowed in the choice of layout and materials for the cabin. Soft, non-reflective plastic, leather trim with contrast stitching and piano-lacquered wood inserts give the 650i's interiors a very plush and sporty feel. My test unit came with a Black and Red colour theme.

The Red perforated seats are comfy and guaranteed to grab attention. However, although it is a four-seater and entry and exit is relatively easy, the rear seats will be a real squeeze for… the rear! If you are going to be heading out to the hills with adults in the rear seats, they are bound to complain of sore backsides and chaffed knees.

The driver and front passenger will, however, have a more memorable experience. The knobs and keys are all angled and positioned on the centre console within easy reach, there are steering wheel mounted controls, F1-style paddle shifters if you choose to drive in manual mode, and the large centrally mounted information display paired with the easy-to-use iDrive controller gives the driver quick access to all the key controls.

A package consisting of High beam assistant, a Head-up display and BMW Night Vision is also available as an optional addition. Other premium functions that are found in BMW's flagship 7-Series such as soft closing doors, Adaptive Drive, Voice control, leather finished instrument panel etc are also optional additions.

Brute force

To focus attention on the 650i's performance, BMW has chosen a more powerful V8 engine than the predecessor. Offering 407 horses on tap, the peak power is delivered by the 4,395cc engine within a narrow, but easily reached 5,500 to 6,400 rpm range. The engine is supercharged using a twin turbo system that helps it generate more power than the larger engine that was used in the previous model.

For a petrol engine, its peak torque of 600 Nm that is available from a low 1,750 rpm to 4,500 rpm is quite amazing. No wonder, right from when I step on the gas, the 650i simply leaves the rest of the traffic behind. There is ample power and torque available right through the rpm band.

Of course, it also helps that the engine has been mated to an 8-speed, quick shifting sports automatic transmission. There are enough gears to go through even at high speeds and in triptronic or manual mode the engine holds the chosen slot all the way to the redline at 7,000 rpm, so you can choose between relaxed automatic or an engaging manual mode of driving.

The powertrain is classic BMW, very refined, very quiet and well packed into the bonnet. The NVH packaging and possibly the wind deflector ensures that there is very little audible evidence of the engine idling or revving in the bonnet even when you have the top down. But the note you will want to hear, of course, is the burbling exhaust that rises and falls as you change gears.

For a large convertible, the 650i's driving dynamics is quite an eye-opener. As I discovered in some of the hilly sections of the old Mumbai-Pune route, this car can be great fun to drive. From the outside the 650i looks big, step in and take the wheel and it seems to collapse into you. A host of BMW technologies for safety and dynamics are at work like automatic stability control, cornering brake control, dynamic traction control and dynamic brake control.

The Drive Dynamic Control option offers three drive modes – Normal, Sport and Sport+. Choosing one of the modes other than the default Normal dynamically changes the settings for the gear shift, speeding it up in Sport and Sport+ modes, and also leads to a stiffening of the steering and engine response characteristics. You have the option of switching off traction control, though the auto traction continues to hover in the background and kicks in during uncontrollable wheel slippage.

The electric power steering with Servotronic is agile and precise, providing the right amount of assistance during slow driving within the city and offering the right amount of feedback in dynamic driving conditions. The 650i convertible also features BMW's EfficientDynamics technologies including brake energy regeneration all aimed at improving the fuel efficiency of the car.

However, the 650i is not really capable of producing a miracle in the mileage department. A full tank of about 70 litres can only go on for a maximum of 600 kilometres and that is in ideal driving conditions. You are more likely to get about 5-6 kmpl, given the natural urge to be ‘fast and furious' in a convertible.

The 650i is offered with a manual transmission too in other markets like the US. Wonder if the buyer here might want to look for that level of engagement with his convertible. Clearly, the 650i is targeted at owner-drivers and with a price tag of over one crore rupees, it is slap-bang in the middle of super sports car territory like the Porsche. The 650i is still a great package overall and has its own strengths to woo buyers who are looking for some post-monsoon top-down action.

muraliswami@thehindu.co.in