2021 BMW 4 Series Convertible detailed: Mercedes-Benz C-Class and Audi A5 rival goes soft with new fabric roof

BMW has revealed the new-generation 4 Series Convertible, which will enter Australian showrooms in the first quarter of next year.

The big news is the 4 Series Convertible is now a soft-top, moving to a ‘panel bow’ fabric roof that is 40 per cent lighter than its preceding hardtop and can be opened or closed within 18 seconds when driving at speeds of up to 50km/h.

This retractability does come at the cost of practicality, though, with cargo capacity ranging from 300-385L, unsurprisingly short of the 4 Series Coupe’s 440L but still up from the previous 220L minimum.

The 4 Series Convertible otherwise share its design with its Coupe sibling, including the tall but relatively narrow interpretation of BMW’s signature ‘kidney’ grille.

Aside from this polarising element, the 4 Series Convertible’s exterior is rather conservative, highlighted by sharp headlights with integrated hexagonal daytime running lights (DRLs), a heavily creased bonnet and pinched tail-lights. Of note, body kits and alloy wheels are variant-specific.

Overall, the new 4 Series Convertible is 128mm longer (4768mm) and 27mm wider (1852mm) than its predecessor, although its height (1384mm) is unchanged. Regardless, it’s on the large side for a mid-sizer.

Inside, the similarities between the 4 Series Convertible and the mechanically related 3 Series mid-size car, let alone its Coupe sibling, are apparent, with both more or less featuring the same cockpit design.

This includes a 10.25-inch touchscreen and a 12.3-inch digital instrument cluster, with both powered by BMW’s latest multimedia system, which supports Android Auto alongside Apple CarPlay for the first time.

That said, the 4 Series Convertible does pick up knee rests as part of its standard-for-Australia M Sport package, and its front doors are naturally different, so much so that they’re completely redesigned, while it also has two rear seats instead of three.

Either way, the 4 Series Convertible stands out from the crowd with its obligatory front neck warmers and wind deflector – and if you look underneath, you’ll find its aluminium shear panel, which helps to increase torsional rigidity.

Under the bonnet, the 4 Series Convertible will available with two turbo-petrol engines in Australia from launch: a 2.0-litre four-cylinder and a 3.0-litre inline six-cylinder.

The former will be available in two tunes: 135kW/300Nm and 190kW/400Nm, dubbed 420i and 430i respectively, while the latter will punch out 285kW/500Nm and be called M440i.

All will be mated to an eight-speed torque-converter automatic transmission with paddle-shifters, with the 420i and 430i rear-wheel drive, while the M440i will use BMW’s xDrive all-wheel-drive system and a limited-slip differential.

BMW Australia will release pricing and full specification closer to the Mercedes-Benz C-Class and Audi A5 rival’s launch. For reference, its Coupe sibling is priced from $70,900 to $116,900 plus on-road costs, but expect it to be positioned much higher.