Performance & drive
What it’s like to drive, and how quiet it is
The BMW 4 Series Convertible range kicks off with the 420i model, which uses a 2.0-litre turbocharged petrol engine producing 181bhp.
It’s our pick in the BMW 4 Series Coupé and it remains so here, as it should be brisk enough for most people and makes sense financially. However, it does have a harder time in the convertible as it has to lug around an extra 165kg (or two fully-grown adults) – 0-62mph, for example, takes a not-so sporty 8.2sec (even the cheapest diesel, the 187bhp 420d, manages 7.6sec) and it feels quite flat low down, so it's just as well that it's happy to rev.
All versions of the 4 Series Convertible benefit from an automatic gearbox that’s less hesitant than the one in the Audi A5 Cabriolet, especially when you flick it into Sport mode. Alternatively, you can take control yourself using the shift paddles mounted on the steering wheel.
Lopping the roof off a car often makes its structure rather floppy, but this is another area in which the 4 Series Convertible is better than direct rivals. You’ll see the rear-view mirror wobbling sometimes, but it takes a big bump for any shake to come up through the steering column. This stiffness is also good news for handling, because it means the steering remains terrifically precise, allowing you to place the nose of the car exactly where you want it.
Adaptive suspension (part of the M Sport Pro Package on lesser models, and standard on M Sport Pro Edition and the M440i) lets you stiffen or soften things up, with even Comfort mode doing an excellent job of propping up the body during hard cornering.
In fact, on pockmarked and uneven B-roads, Comfort is a better bet than the more focused Sport setting because its extra suppleness stops you being bounced off course. Whichever mode you select, there’s an agility that's surprising given the hefty weight of the 4 Series Convertible. You'll have far more fun than you will in the A5 Cabriolet or Mercedes C-Class Cabriolet.
Despite this ability in the twisties, the 4 Series Convertible's adaptive suspension gives it a comfortable ride, even with big 19in wheels fitted. It rounds off all but the nastiest bumps and potholes and deals with undulating tarmac with a great balance of comfort and control, making this a car you’d happily cruise around in all day. We’ve yet to try the standard suspension set-up but we’ll update you on this when we do.