BMW says that it paid close attention to two-seater body, powertrain and chassis to ensure it arrives with genuine sports car performance pedigree.
This means that the German carmaker has made it larger at 4,336mm-long (+97mm), 1,864mm-wide (+74mm) and 1,306mm-tall (+15mm).
The more powerful M40i Roadster will sport a closer 1,595mm (front) and 1,582mm (rear) track.
The sDrive30i will roll on 18 x 8.0inch (front) and 18 x 9.0 inch (rear) wheels with a staggered setup of 225/45 (front) and 255/40 (rear) tyres.
The M40i will use wider 18 x 9.0inch (front) and 18 x 10inch (rear) wheels and will be fitted with 255/40 (front) and 275/40 (rear) tyres.
As for the M40i, the wheels can be upgraded to front 19 x 9.0inch with 255/35 tyres and rear 19 x 10inch with 275/35 tyres.
Regardless of tyre size, the Z4 will have a cruising altitude of 119mm off the ground.
Powerwise, the 1,491kg (kerb) SDrive30i, that will be arriving first, will have a standard 50-litre fuel tank feeding the 2.0-litre (1,998cc) B46 four-cylinder turbocharged mill.
With a compression ratio of 10.2:1 and higher pressure injectors (350bar / 5,076 psi), the engine is now capable of producing 255hp (+15hp) from 5,000 to 6,500rpm and 400Nm (+47Nm) of torque from 1,500 to 4,400rpm.
The heavier M40i at 1,562kg (kerb) will use a 3.0-litre (2,998cc) B58 inline-six engine with a higher compression ratio of 11.0:1 that have been fitted with a more reactive turbocharger, water-cooled exhaust manifold integrated into the cylinder head and the same higher pressure injectors.
Both engines will be managed by an eight-speed Steptronic automatic transmission with paddle-shifters and launch control to allow the Z4 to sprint from standstill to 100kph in 5.3 seconds (sDrive30i) / 4.0 seconds (M40i) before reaching an electronically limited top speed of 250kph.
The same transmission fitted in the M40i will be configured with M-specific shift-characteristics to complement the straight-six engine’s power delivery.
For handling, the Z4 has been fitted with a newly designed double-joint spring strut suspension at the front and a new five-link suspension in the rear, a first for a BMW Roadster.
The Munich-based carmaker says that this chassis combination offers the best balance between sports car handling and ride comfort.
The front suspension subframe and control arm mounting points are extremely rigid, which lends to precise cornering characteristics as well as having a beneficial effect on the drivetrain’s acoustics.
The new rear suspension also employs a lightweight aluminum/steel design. The large supporting base and very rigid structure of the rear axle subframe as well as the bracing used for connecting it to the body result in extremely precise wheel guidance.
Another standard feature is the sport steering with variable power assist and ratio. This particular version of the power steering system is designed to promote not just straight-line stability, but also precise feedback during cornering and low-speed maneuvering.
The Adaptive M Sport suspension, M Sport brakes and M Sport differential are all standard on the M40i and as an added upgrade option for the sDrive30i.
Driving modes will include COMFORT, SPORT and SPORT+ modes and the two latter modes will drop the roadster's ride-height by 10mm with the Adaptive M Sport suspension which includes electronically controlled dampers.
An electric motor generates a locking effect in the differential that equalizes torque distribution between the inside and outside rear wheels when cornering, making it possible to power out of bends with greater momentum.
The active differential lock also works effectively in reducing both understeer and oversteer.
The list of options includes Active Cruise Control with Stop & Go function, Lane Change and Lane Departure Warning systems, as well as a Parking Assistant including Back-Up Assistant.
The new BMW Z4 is also the first Roadster to be made available with an optional BMW Head-Up Display.
Lookswise, there are a number of signature details that forms the defining features of the new Z4.
Firstly, the Z4 possesses a sculpted front end with large air intakes, a low, broad BMW kidney grill and headlights positioned at the outer edges to showcase the carmaker's new design direction.
The design of the headlight units are a first for the brand, with the two light sources positioned one above the other.
The vertical design is cut off at the top by a diagonal accent strip with integral direction indicator.
The new Z4 is equipped with LED headlights as standard and Adaptive LED headlights available as an option.
The long hood with arrow-shaped contour lines directed at the kidney grill straddles the wheel arches in a “clamshell” style characteristic of classical sports cars of the past.
An upper character line runs from the bottom of the hood to the tail lights, while a second, lower character line emerges from the large air vents behind the front wheel arches - all of which mimics the flow of air sweeping along the new Z4.
The rear end’s look is strengthened by the side surrounds and the trapezoidal exhaust tailpipes flanking the diffuser.
There is a choice of eight colors for the exterior, including Frozen Grey for M Sport models.
The powered soft-top roof can be opened and closed in 10 seconds at speeds of up to 50kph and comes in Black as standard or Anthracite with silver effect as an option.
The Z4 sDrive30i arrives with Sport Line as standard with added performance enhancements that include the optional M Sport or Track Handling packages.
The highlights of the M Sport package include a three-section air intake for the front apron, prominent side skirt contouring, a rear apron with highly distinctive side surrounds, 19-inch M light-alloy wheels, M Sport or Adaptive M suspension, an M Sport steering wheel and Active Driving Assistant.
The Z4's driver-centric cockpit can be upholstered in SensaTec and Vernasca leather with a special Vernasca/Alcantara upholstery available for M Sport vehicles.
Features and fittings include a push-start button, a standard 205-watt 10-speaker hi-fi audio system, electric sports seats featuring integral head rests, cup holders under the center armrest cover (which folds open in two sections) and larger door pockets.
Under the options list, owners can opt for dual-zone automatic climate controls, automatically dimming and folding exterior mirrors and a keyless-entry system with soft-top operation via key FOB.
Also included are the instrument panel LED fiber-optic accent strips, 12-speaker 464-watt Harman Kardon surround sound system with digital amplifier, M sports seats with electro-pneumatic backrest width adjustment and a boot-through loading system to help with handling longer items,
Safety comes with the standard availability of Anti-lock Braking System, Dynamic Traction Control, Cornering Brake Control and Dynamic Brake Control, Forward Collision Warning and Daytime Pedestrian Detection with City Braking function and Lane Departure Warning system as standard.
The range of functions also includes the Back-up Assistant, which offers the highly convenient option of automated reversing in situations where there is little margin for error or the driver does not have a clear view.
To do this, the system stores the steering movements for the section of road the car has just driven forward.
It then traces these last forward movements when reversing and keeps the car on exactly the same path for a distance of up to 150 feet.
All the driver has to do is operate the accelerator and brake pedals and keep an eye on the area around the car.
The latest-generation of the iDrive comprises of a high-resolution digital 12.3-inch instrument cluster display and a 10.25-inch centre display.
The system offers many hardware upgrades including new haptic controls on the iDrive controller and a tablet-like touch interface.
The seventh incarnation of iDrive, which runs the latest BMW Operating System, has a fully digital design that has customizable widgets of information.
This new level of personalization is then stored in the BMW Cloud and can follow the customer to other BMW vehicles.
Various information from categories such as driving, entertainment, navigation, connectivity, and the vehicle info itself, can be selected in nearly any combination in any of four layouts on the Center Display.
This new design opens space in the middle for routing and navigation, if desired.
Information from the center display can also be shown within the tachometer. Additionally, the chosen driving mode will determine the visual display style.
Other elements of the BMW Live Cockpit Professional are the Navigation Professional system, a hard-drive-based multimedia system with 20GB of memory and two USB ports, plus Bluetooth and Apple CarPlay interfaces.
The driver can be automatically identified and personal settings activated either using the traditional key FOB or by downloading the driver’s personal settings from the BMW Cloud.
Drivers can enjoy the full benefits of the car’s intelligent connectivity capabilities through vehicle apps such as news, weather, office and online search.
Other capabilities include Intelligent Emergency Call – which automatically summons swift assistance in an emergency – and regular updates for the navigation system’s maps.
Customers can continue to download various new digital services individually as they become available or renew existing services via the ConnectedDrive Store.
With regards to BMW Connected, it is an all-embracing concept designed to seamlessly connect the driver and their smartphone with their vehicle.
At the heart of it all is the Open Mobility Cloud, which allows the app to connect the car with the customer’s digital devices.
These could include the iPhone and Apple Watch, smartphones and smartwatches running the Android operating system, Alexa-compatible smart devices and Google Home.
The system calculates the optimum departure time based on real-time traffic information and notifies the driver with a message on their smartphone when it is time to leave.
As the vehicle is linked up via the Open Mobility Cloud, it is able to access the calculated route directly when the navigation system starts up.
Lastly, the Z4 is Remote Software Upgrade capable, which is a feature that helps keeps the vehicle up to date with the latest software.
All updates can be loaded over the air, similar to smartphones and the upgrades can be loaded onto a smartphone via the BMW Connected app when connected to a Wi-Fi network or imported directly via the BMW’s built-in SIM card.
