BMW presents Concept Z4

BMW has traded away its traditional long-nose, short-tail sports car design for its all-new Z4 roadster, which has been previewed by the Concept Z4 ahead of its debut at this weekend's Pebble Concours in California.

The third generation of BMW’s Z4 will share its core design and layout with Toyota’s born-again Supra and one of the compromises the Bavarians have made is a major change to the roadster’s profile as a result of its new dual parentage.

Still, it doesn’t seem to lose a lot of form in the transition and continues the theme of deep, broad air intake aprons BMW began with the Concept 8 Series in May.

While BMW isn’t yet talking about the production powertrains the new Z4 will run, it’s steering clear of the V6 options Toyota is favouring for its Supra sibling.

Instead, this is all about getting people used to the new design language for the Z4 and its shortened nose (which should, as a byproduct, ramp up its steering feel).

“The BMW Concept Z4 is an all-out driving machine,” the BMW Group’s Senior Vice President of Design, Adrian van Hooydonk, said.

“Stripping the car back to the bare essentials allows the driver to experience all the ingredients of motoring pleasure with supreme directness. This is total freedom on four wheels.”

Stripping the car back to basics and returning to the roots of its original forebear, the Z3, also means ditching the old Z4's heavy, complex folding metal roof in favour of a multi-layer cloth roof and two large buttresses behind the head restraints.

Besides saving weight, it will also help lower the centre of gravity of the Z4, with sources suggesting Toyota had no interest in compromising its Supra for the complex roof system.

Exterior design
Borne of a technical tie-up between Toyota and BMW that began in 2012 and has spread to hybrid and fuel-cell programs, the Z4/Supra twins aren’t identical in the same way as the Subaru BRZ and Toyota 86, above which the Supra will positioned in the Japanese car-maker's range.

Instead, the BMW way for the J29 Z4 has been to sculpt the living daylights out of the side paneling in a way that both harks back to the first-generation Z4 and looks forward to the 8 Series.

Spotted several times in testing, when it was widely expected to be called the Z5, the new Z4 is rumoured to be clothed in lightweight body panels which will likely employ some of the carbon-fibre-reinforced plastics technology developed for both the i3 city-car and i8 supercar.

“The BMW Concept Z4 expresses the new BMW design language from all perspectives and in all details,” van Hooydonk said.

“From the dynamic-looking front to the striking flanks to the clean-cut tail end: a few lines and the subtle interplay between surfaces are enough to generate a sense of power and emotion.”

That language begins at the nose, with BMW aiming to deliver the emotion of a hunting shark, with aggressive, long headlights, a protruding front splitter and just enough of its traditions in the kidney grilles.

Where the original Z4’s flame-surfaced flanks started suddenly, the similar sculpting on the side of the third-generation model begins at the oversized air breathers behind the front wheels and continues until the upper crease forms a wedged waist line and the lower one pushes the sill lower and runs into the rear wheel-arch.

While there are hints of the outgoing 6 Series in the rear-end, it works strongly on the new Z4, forcing it lower than on its predecessors until it seems flat and wider than the footprint suggests.

Close to production styling and teased several times recently, the Concept Z4 rides on 20-inch wheels with five double spokes and the Energetic Orange paintwork shrink-wraps the clamshell bonnet, with its stylised gill vents.

Interior design
The larger interior (and larger boot) is also ready for production, though most customers will probably prefer two seats of the same colour. BMW did that to emphasise that the J29 was a driver’s car, aiming up at Porsche’s 718 Boxster in a way its predecessors never quite did.

The instrument cluster and the central infotainment and ventilation stack are tilted unashamedly towards the driver, with the infotainment screen now very close to the instrument cluster (though not quite in an E-Class Mercedes-Benz way).

There’s also a full colour head-up display, while the infotainment system switches to a touch-screen set-up and includes navigation, playlists, apps and smartphone compatibility thanks to BMW's sixth-generation iDrive6 system.

To reaffirm its driver’s-car credentials, BMW has slotted a lap timer into the steering wheel, with bright red buttons to start and stop it within easy thumb reach. There’s a digital lap timer display built into the bottom part of the steering wheel, reading down to hundredths of a second.

It retains its traditional gearshift lever, too, and moves the red start button alongside it on the centre console, but autonomous driving aids will be thin on the ground in this driver's car.

The button layout on the console indicates the car will also receive adaptive damping and will still have Eco Pro, Comfort and Sport modes. It will also retain the ability to completely switch off its skid-control systems.

Under the bonnet
The Supra (G29) will differ in another significant way, with recently leaked BMW documents suggesting only the Z4 would come with a manual gearbox, while the Toyota would only run the BMW-sourced eight-speed automatic transmission.

Both rear-wheel drive cars will have 2.0-litre turbocharged direct-injection four-cylinder engines as their entry models, with Toyota’s early documents adopting a very BMW-esque nomenclature in calling them 20i and 30i.

They will also enjoy mild-hybrid charging via 48-volt electrical systems and an integrated starter generator.

Both conventional line-ups top out with a version of BMW’s six-cylinder turbocharged M 40i engine, which suggests a ceiling of around 272kW of power and 465Nm of torque.

Both the Z4 and Supra are also technically pre-engineered to receive a quad-motor hybrid system, with a 2.0-litre turbo-four combined with three electric motors to create an all-wheel drive monster.

As well as the M version, BMW hasn’t ruled out a more potent variant perhaps called the Competition Package and -- just as the Supra could eventually be produced in convertible form -- it's possible BMW could make a a hard-top coupe derivative of the Z4 later in its life.

Intriguingly, both cars will be built at Magna Steyr’s production plant at Graz, in Austria, which once delivered the MINI Countryman and Paceman, and Magna has penciled in combined production of 60,000 cars a year from both brands.

That would be a big step up from the current (2009-2017) Z4, which was heavier and less interesting to drive than its predecessor. BMW sold 2.367 million cars last year and the Z4 accounted for only 0.3 per cent of them.

More information is expected to be revealed following the Z4 concept's official reveal.