The M4 and its folding hard-top roof make up the replacement for the old M3 Convertible. The new number is part of BMW’s efforts to separate its four-door and two-door cars, which now wear odd and even numbers respectively.
The old M3’s eight-cylinder engine has been downsized to a “mere” 3.0 litres, but it’s now turbocharged to offer even headier performance. BMW says their task, in line with customer feedback, was to make the M4 Convertible lighter, more efficient and more aggressive.
The M4 certainly makes a more dramatic entrance, with a wider, bolder front end carving a path down the outside lane of the autobahn like a hot knife through soft cheese. Its dimensions, especially its width, boost its road presence close to that of older M5s, but it does make the new model something of a handful on narrower roads, unless you like pretending that your bonnet has an itch that only hedgerows can scratch.
It will be interesting to see whether the loss of the iconic M3 badge will be enough to dent its image. It’s unlikely, but technically the M4 badge has no heritage or sub-brand image of its own.
In many drop-tops the roof folding mechanism gets in the way of luggage space, and the M4 is no exception. Cleverly, though, at the touch of a button on the inside of the boot lid, the whole folded roof assembly can be moved up and out of the way so that bags can be slotted in beneath.
There are a few small spaces for odd bits and pieces in the cabin, and if you’re aiming to use those rear seats you’ll be pleasantly surprised by the long bases that give good under-thigh support and help offset the impression of slightly cramped legroom. There’s actually more there than you think.
The best thing about the M4 Convertible is the absolutely outrageous noise the four exhausts treat you to when the top is down. A deep, barrel-chested growl mutates into a full-blown roar that reaches earthquake proportions, in contrast to the lovely but slightly synthetic woofle when the roof is raised.
There’s quite a lot of extra weight due to chassis strengthening to compensate for the loss of the roof, and that causes a slight reduction in the M4 Coupe’s explosive performance. That said, it pounds its way past 140mph with ease, staying astonishingly stable all the while.
In corners it’s hugely composed thanks to very well tuned suspension and wide, grippy tyres. Most drivers are unlikely to find themselves reaching its limits of adhesion very often, unless you count wheelspin away from the line.
Without any optional extras the M4 stands alone in terms of its breadth of capabilities for the price. This one, though, has many thousands of pounds’ worth of extras. It offers its best value with as few options as possible.
Those who love their performance cars but also want a weekend toy practical enough to take their growing kids along will love the M4 Convertible. It’s more than a little naughty, but at a moment’s notice it can be civilised, comfortable and luxurious.
Car BMW M4 Convertible
Engine 3.0-litre, 6cyl, turbocharged petrol, 426bhp, 406lb/ft
Performance Top speed 155mph, 0-62mph in 4.6 seconds
Economy 30.1mpg combined
CO2 emissions 213g/km