2018 BMW Z4 Concept shows bold design direction of upcoming roadster

In place of the customary vertical bars, the insides of the kidney grille feature a new mesh that van Hooydonk said was inspired by the functional treatment used on early BMW roadsters, including the iconic 328 Mille Miglia. 

The long bonnet, meanwhile, retains the clamshell design of previous Z4 models. On the concept, it features two vents. However, these are unlikely to make production, according to Autocar’s sources. 

Certain licence has also been taken with the concept’s windscreen, which does not have the sturdy surround of the production version, and the two metallic domes conceived to act as rollover protection will be replaced by more conventional rollover hoops on the production roadster. 

Although BMW has yet to officially confirm it, the new Z4 eschews the folding hard-top of today’s model for a traditional fabric hood. Already sighted on prototype versions of the two-seater, the hood folds and stows underneath a dedicated tonneau cover at the rear of the cabin. 

BMW has provided a clear glimpse of the look and layout of the new Z4’s interior. The production car will have a flowing dashboard and relatively wide centre console resembling those of the concept. Features such as the digital instrument panel and head-up display included in the show car will also make their way on to the new roadster. However, the brushed aluminium and carbonfibre trims will be replaced by more cost-effective composite plastic materials. 

Accommodation is said to have improved thanks to the car’s increased overall dimensions. Boot capacity is also claimed to top the 310 litres of the outgoing Z4. 

The new Z4 is underpinned by BMW’s CLAR (cluster architecture) platform. It is already used by the 2, 5 and 7 Series and is also set to be adopted by the upcoming 8 Series and the successor to today’s 3 Series. The CLAR platform is allied to a multi-material body structure, featuring a combination of high-strength steel, aluminium and magnesium. Insiders suggest the new roadster will tip the scales at under 1400kg in its most basic form, despite the increase in dimensions. 

An internal BMW document seen by Autocar revealed that the new Z4 will be offered with a choice of two petrol engines from the start of sales. The first is a turbocharged 2.0-litre four-cylinder unit expected to develop around 181bhp in the Z4 sDrive20i and 248bhp in the Z4 sDrive30i. The second engine powers the Z4 M40i and is the latest incarnation of BMW’s B58 turbocharged 3.0-litre in-line six-cylinder engine. It is rumoured to develop the same 355bhp as it does in the X4 M40i. 

A full-blown M version of the roadster, running the BMW performance car division’s 425bhp twin-turbo 3.0-litre in-line six-cylinder, has also been mooted, but it has yet to be officially confirmed by BMW.