Seen in a compound at one of the Munich brand's development facilities alongside other disguised mules, the drop-top is, as expected, close to the hard-top in terms of its body design. It'll be the smallest four-seat convertible model BMW makes because the next-generation 2 Series will come in coupé and four-door forms only.
With the current 2 Series and new 8 Series Convertible adopting a cloth roof, it’s not a huge surprise that BMW has elected to ditch the folding metal roof for the second generation of the 4 Series. The decision also brings the car in line with its closest rivals: the Audi A5 and Mercedes C-Class cabriolets.
Doing so reduces the complexity of engineering and producing an intricate folding hard-top system and is likely to improve the long-term reliability that complicated folding hard-tops are often criticised for lacking.
The move will also reduce the car’s kerb weight, aiding handling, performance and fuel efficiency. Expect the new convertible to be less than 100kg heavier than the coupé. With less mass to store underneath the bootlid when the roof is down, improvements in rear seat and luggage room are possible, too.
The new 4 Series revealed a bold and controversial front-end styling direction for BMW last month. It also introduced a new aluminium-intensive platform, a wider and longer body with a wheelbase matching that of the 3 Series saloon, and the latest array of technology.
It will go on sale with three petrol engines and one diesel. Two 2.0-litre four-cylinder petrols offer 181bhp (420i) and 254bhp (430i), while a 48V mild-hybrid 2.0-litre four-cylinder turbo diesel delivers 187bhp (420d) and official fuel economy of between 67.3mpg and 72.4mpg.