Going Topless

Along with dancing and golf, organisation isn’t really one of my strong suits. But even for me, getting BMW’s new 640i convertible on test on the same weekend that I needed to drive my girlfriend, my bike, bundles of kit and a BBQ to the New Forest for a triathlon was staggeringly short-sighted. It could only have been worse were I taking delivery of a scooter or, God forbid, a G-Wiz.

But a quick visit to BMW’s website, and the situation was looking up: the new 6-series is 74mm longer and 39mm wider (though 9mm lower) than its predecessor, and the boot has an impressive capacity of 350 litres with the hood up (300 litres when down). I’d never really thought about my bike in terms of volume, and after a rough calculation in my head involving dismantled bits of frame and wheel and several hundred bottles of Ribena (the closest reference point I had for any kind of litreage) I was none the wiser. Clearly, I was just going to have to stuff it all in and hope for the best.

I needn’t have worried – the 640i swallowed us and all our clobber whole, with room to spare. It’s no Tardis – at 11cm shy of 5m long and just under 3m wide it’s undeniably a big car – but it’s roomier than you’d expect from a 2+2 convertible with a substantial folding roof.

Unusually, BMW launched the new 6-series in convertible form first (the coupé followed soon after) and it’s not hard to see why. Not only is the 2011 model a more handsome car than its predecessor (its sleepy eyes and bizarre protruding rump were always Marmite features), but the drop-top is the looker of the new pair, hood up or down. The roof’s chrome trim and rear ‘fins’ are apparently inspired by the deck of a speedboat, and the overall effect provides as convincing an argument as you’ll find for rag-top over folding hard-top.

And on the move, hood up, there’s little on the inside to suggest you don’t have a metal roof over your head – a fraction of extra wind noise on the motorway, perhaps, and a letterbox of a rear window that makes the optional reversing camera near essential. And while I’m at it, the camera emerges James Bond-style from underneath the BMW badge on the boot when you select reverse; there’s fun to be had in shooting pedestrians a menacing glance before you start backing out, and watching them freak out as the badge starts to rotate.

Needless to say, I didn’t do this. No sir. I was too busy shepherding my precious cargo down the M3 and acquainting myself with the 640i’s armoury of other talents. The large, spacious cabin and cosseting ride make the big convertible a very pleasant place to be holed up for a couple of hours – swathes of leather and brushed metal look modern and feel appropriately luxurious, while BMW’s now-brilliant iDrive console (housing the navigational gubbins, multimedia and BMW support services) sits in the centre of the dash, angled towards the driver.

And, for the first time in a 6, a head-up display, which projects information (including speed, navigation instructions and the speed limit) onto the windscreen in front of the driver, is available as an option. Like smartphones and ATMs, you’ll wonder how you ever coped without. There’s room in the back, too – more than before thanks to that extra length and width – though only your kids (or tiniest friends) will thank you for putting them there; it’s undeniably a 2+2. Still, if they complain, remind them of the generous capacity of that boot.

The one thing the 640i doesn’t have is a 4.4-litre V8 engine – that’s in its big brother, the 650i – though you’re not likely to miss it too much. The turbo-charged 3.0-litre straight-six in the 640i provides plenty of grunt throughout the rev range (peak torque of 450nm comes between 1,300 and 4,500rmp) and hauls the car from 0-62mph in a very respectable 5.7 seconds, with a soundtrack to match. But where the six-pot really trumps the V8 is at the petrol pumps – combined cycle fuel consumption is 35.8mpg compared with 26.4mpg for the bigger engine.

To unlock the 640i’s full potential you’ll need to tick the box marked ‘Adaptive Drive’, which allows you to select from a range of performance settings. ‘Comfort’ does what you’d expect it to while ‘Sport+’ weights-up the steering, sharpens throttle response and limits intervention by the car’s stability control systems. It also eradicates body roll to a pretty remarkable degree, so even if the styling echoes that of a boat the handling doesn’t – the BMW’s far more capable in the twisty stuff than a car of its size has any right to be.

Even so, you sense that were the 640i to choose its own purpose in life it would be as a grand tourer, whisking its occupants to the South of France with the hood down under a blazing sun, rather than soaking up the bumps of English country roads. Or, for that matter, lugging some idiot’s clobber around Hampshire. But you know what? I wouldn’t have swapped the 6-series for anything else that weekend.

As happy accidents go, this was as good as they come – if you ever see a G-Wiz with a bike and a BBQ sticking out the window you’ll know I wasn’t so lucky next time around.

bmw.co.uk