The BMW i8 has been a technological pioneer and the world’s best-selling plug-in hybrid sports car since it arrived in 2014. Now in 2018 it is joined by a new model that adds further allure to the arena of sustainable driving pleasure.
The all new BMW i8 Roadster takes the combination of emissions-free and high-perfromance motoring and adds open-top thrills. It is unique in offering such performance and silent acceleration with the pure sensation of roof-down driving.
The i8 Roadster is on sale now with prices starting from £124,735 OTR
First shown as a concept car back at the Beijing Motor Show in 2012, the BMW i8 Concept Spyder showed what a roofless version of the, as yet, unlaunched i8 Coupé might look like. It too featured clever packaging and dihedral doors despite the design challenges of not having a fixed roof.
Jump forward to 2018 and much of that striking original concept car has been retained in this finished vehicle. From innovative packaging of the roof, through to retaining the iconic doors and maintain the i8 family side profile, something many roadsters and convertibles fail to do when switching from hard-top to soft-top variant.
Driver and passenger in the all-new BMW i8 Roadster will look up to find either the open sky or a high-quality, all-season fabric soft-top with high-level soundproofing. All-electric operation ensures the roof opens or closes in an almost silent hush, within 15 seconds and while travelling at up to 31mph. This makes the i8 Roadster the BMW with the fastest opening roof across all the company’s models.
The i8 Roadster is unique in offering a fabric soft-top which stows into a perpendicular position in the rear when opened. This allows for far better packaging and day to day practicality. The three segments of the roof fold vertically in a Z-shape, thus taking up very little space and leaving an additional 100 litres of storage capacity between the roof box and the seats. This is in addition to the 88 litres of cargo space in the rear compartment.
Opening the roof raises the rear window automatically by around 30mm, reducing air turbulence inside the cabin and ensuring passengers can enjoy the pleasure of open-top driving with minimal disturbance. The driver can adjust the height of the window at the touch of a button and control airflow as desired.
Intelligent, lightweight design and innovative production technology play a key role in the car’s construction. For example, aluminum elements connecting the roof with the body of the car are produced via a new 3D printing process. This manufacturing method breaks new ground in the industry and allows the parts to be produced in a geometric form, which would not be possible using conventional casting techniques.
The framework was provided by the new LifeDrive vehicle architecture for BMW i models, whose horizontally split structure comprising an aluminium chassis and a CFRP passenger cell offers an exceptional degree of design freedom. The new i8 Roadster translates the BMW i design language to another vehicle concept, fusing the proportions of the i8 with signature roadster features to give it a character all of its own.
The C-pillars are adorned with beautifully made model-specific badges bearing the inscription “Roadster”. A similar logo can be found on the tail of the sporty two-seater.
The design cues common to the i8 Coupé also appear on the i8 Roadster and include dihedral doors that open forwards and upwards as well as optimised aerodynamics. The low bonnet, the BMW kidney grille, air flap control system, Air Curtains in the front apron, sealed underbody, contoured side skirts, “stream flow” lines of the car’s flanks, and air ducts between the rear lights and roof frame allow the air to be channeled extremely effectively.
The flow of cooling air at the front has now been rerouted, instead of flowing out through the outlet in the bonnet the air escapes at the sides of the car near the wheel arches and into the underbody. This ensures a pleasant cabin temperature is maintained at all times, especially when travelling with the roof down.
Two sources of power for the BMW i8 Roadster
The new BMW i8 Roadster is powered by a hybrid synchronous electric motor and a three-cylinder petrol engine with BMW TwinPower Turbo technology. The engine’s power is fed to the rear wheels through a six-speed Steptronic transmission, while the electric motor propels the front wheels via a two-speed automatic gearbox. The end result is a hybrid-specific all-wheel-drive system that glues the car to the road.
However, to enhance low emissions running and overall performance the number of driving situations where the electric motor is solely responsible for powering the car has been significantly increased. By contrast, the combustion engine is only brought into play when accelerating hard, and is switched off again more frequently with a measured driving style.
Underpinning its improved emission-free range is an updated version of the i8’s lithium-ion battery. The high-voltage unit is located centrally under the car, and its cell capacity is increased from 20 to 34Ah. All of which means the motor has more energy at its disposal. Plus, the cell configuration allows a 12hp increase in peak output to 143hp. And in typical electric motor fashion it generates its maximum torque from rest which means it is ideally equipped to deliver razor sharp responses from the slightest movement of the accelerator.
The improved technology means the i8 Roadster can cover up to 33 miles with zero emissions, broadening the reach of all-electric mobility well beyond the city limits.
The battery cells’ higher capacity means that the proportion of all-electric driving can be increased substantially, even in hybrid mode. With the default driving mode engaged, the BMW i8 Roadster is capable of pulling away and reaching speeds of up to 65mph purely on the electric motor’s power, making it possible to drive with zero emissions not just in town, but on country roads as well. If the eDrive button is pressed, the all-electric threshold is increased further to 75mph.
Three-cylinder petrol engine with improved sound and lower emissions
The i8’s combustion engine has also undergone further improvements. The turbocharged three-cylinder unit featuring direct injection and VALVETRONIC variable valve timing extracts a maximum output of 231hp from its displacement of just 1.5-litres, plus peak torque of 320Nm. It is pleasantly refined and generates a distinctive soundtrack that now has an even sportier note when its power reserves are called upon. The engine also runs more cleanly, as it now comes equipped with a particulate filter as standard that effectively absorbs all the particulate matter contained in the exhaust gases.
The system output produced by the electric motor and engine acting in unison has increased to 374hp. The new i8 Roadster takes 4.6 seconds and has an electronically limited top speed of 155mph.
Combined fuel consumption, as calculated in the EU test cycle for plug-in hybrid vehicles, stands at 141.2mpg– which equates to petrol CO2 emissions of 46g/km– plus 14.5kWh of electricity In everyday driving, the i8 Roadster returns fuel consumption and emissions figures that undercut those for conventionally powered sports cars with similar outputs by around 50 per cent. A typical commute through city traffic and along country roads can be negotiated with fuel consumption of over 56mpg. On long-distance journeys with prolonged sections of country and motorway driving, the intelligent energy management ensures that average economy betters 40mpg.
Maximum driving pleasure with intelligent energy management and all-wheel drive
In hybrid mode, the electric motor provides a power boost to assist the engine when vigorous acceleration is required. The electric motor is also able to recuperate energy and feed it to the battery on the overrun and under braking. The petrol engine’s high-voltage starter-generator can similarly generate additional reserves of electricity, thereby ensuring that sufficient energy is on tap at all times.
The blend of dynamism and efficiency is further honed by the intelligent energy management’s proactive function. When the navigation system’s route guidance is activated, the energy management ensures the electric motor is employed as extensively and as wisely as possible from an efficiency point of view. The system analyses the route and prompts the powertrain to run on purely electric power, particularly over low-speed sections of the journey.
BMW i8 Roadster with model-specific chassis and body features
The high-end chassis technology in the new i8 Roadster is based on a double-wishbone front axle and a five-link rear axle, whose aluminium components have been engineered for optimum weight and rigidity using specific design techniques and production processes. Also as standard on the i8 Roadster is Dynamic Damper Control. The bespoke tuning of the suspension and damping systems, specially configured steering characteristics, a firmer roll stabilisation set-up and precise tweaks of the DSC parameters together ensure the new i8 Roadster boasts all of the plug-in hybrid sports car’s hallmark handling and performance qualities.
The lightweight design approach was meticulously adapted to the specific requirements of the Roadster model. The open-top comes with new frameless dihedral doors made from CFRP, with an aluminium outer shell, while the windscreen frame is made entirely from CFRP. This ultra-strong high-tech material is ideally equipped to provide exceptional rigidity, maximising the car’s occupant protection even if it rolls over. CFRP is also used to manufacture the side skirts with their extra-large cross-section. The skirts also contribute to the body’s stiffness, as do the additional panels in the rear suspension and the specially designed struts for the front and rear axle. Thanks to the high-strength CFRP body, the chassis and body elements specific to the BMW i8 Roadster result in an extremely small weight gain when compared to other open-top models. The unladen weight of the i8 Roadster stands at 1,595kg, just 60kg more than the Coupé.
Driving Experience Control switch and eDrive button provide five driving modes
Drivers will find an eDrive button in the centre console alongside the Driving Experience Control switch to allow them to adapt not just the vehicle’s set-up but also the drive system’s operating strategy. This provides a total of five driving modes to choose from: hybrid drive with COMFORT, SPORT or ECO PRO settings and all-electric driving in COMFORT or ECO PRO mode. If the eDrive button is pressed in either COMFORT mode – which strikes an even balance between sporty and efficient characteristics – or ECO PRO mode (designed for particularly fuel-efficient driving), power is provided by the electric motor alone up to a speed of 75mph. The combustion engine will only cut in automatically if the battery’s energy reserves are nearly fully depleted or the driver summons full power via kickdown.
It is in SPORT mode that the intelligently controlled interaction between electric motor and combustion engine can be experienced at its most intense. Both power units deliver extra-sharp performance, accelerator response is faster and the power boost from the electric motor is maximised. And to keep the battery topped up, SPORT mode also activates maximum energy recuperation on the overrun and under braking. The intelligent energy management’s mode of operation can be visualised by calling up the energy flow graphic in the Control Display via the iDrive menu.
The instrument cluster takes the form of a fully digital multifunctional instrument display, which shows the car’s speed and driving status information in a format and colour scheme selected to suit the driving mode engaged. Traditional, orange-coloured circular dials appear in SPORT mode, in COMFORT mode, a blue “power meter” display keeps the driver up to speed on what the electric motor is up to, and ECO PRO mode supplements this with an efficiency gauge.
Non-dazzling laser headlights with high-beam range of 600 metres
The BMW i8 was the world’s first production vehicle to be equipped with pioneering laser headlights. The non-dazzling BMW Laserlights with BMW Selective Beam achieve a remarkable high-beam range of up to 600 metres, double that of the full-LED headlights fitted as standard on the i8 Coupé and Roadster, which are themselves exceptionally powerful.
Another optional extra available for both models is an acoustic pedestrian warning, which makes it easier for pedestrians to notice the vehicle when driving at low speeds in all-electric mode by generating a distinctive identifying sound similar to the noise from a turbine. The acoustic pedestrian warning is active up to 18mph, i.e. at the sort of speeds where tyre noise and wind noise are barely audible.
BMW Connected and ConnectedDrive: sustainable mobility as an integral part of digital lifestyles
The enthralling driving experience offered by a plug-in hybrid sports car is further enriched by the digital services offered by BMW ConnectedDrive.
Intelligent connectivity between vehicle, driver and the outside world paves the way for remarkably efficient mobility, increases comfort, expands the infotainment offering and helps with individual mobility planning.
The BMW Connected App is a personal mobility assistant that interfaces the vehicle with the customer’s smartphone or smartwatch. This turns the personal mobility assistant into a seamlessly integrated component of the driver’s digital life, available anytime and anywhere.
The new BMW i8 Roadster also benefits from the latest digital services offered vis the BMW Connected App and BMW Connected+. These include intelligent route planning, complete with refueling stops at a charging station or fueling stations (Send my Routes to Car), sharing of the current trip status by text message and live link (Share Live Trip Status), personalised display of the relevant in-vehicle information (BMW Onboard), seamless transfer of route guidance to a smartphone or smartwatch once the car has been parked (Navigate Door-to-Door) and linking of contact details and addresses so they can be imported directly into the navigation system (My Destinations).
ConnectedDrive Services are also included as standard, providing access to functions such as Concierge Services, Remote Services and Real Time Traffic Information, which now includes Hazard Warning and On-Street Parking Information. The car’s built-in SIM card also allows drivers to use the BMW Teleservices and Intelligent Emergency Call with automatic locating and accident severity detection. ConnectedDrive Services are also required to access additional services such as Online Entertainment, as well as allowing the integration of various apps.
The BMW Display Key and BMW Connected for smartphones and smartwatches allow the vehicle status to be checked at any time. The standard BMW Display Key provides the driver with a handy way of accessing important vehicle status information at any time. Not only can the fuel level, battery charge, range and service information all be viewed on its 2.2-inch touchscreen display, the BMW Display Key can also be used to operate the door locks and power windows. Meanwhile, the BMW Connected App also allows the most important vehicle information – such as the remaining range and battery charge – to be accessed on the customer’s digital touchpoints (e.g. their smartphone or smartwatch). The functions which can already be called up from the customer’s home using the Alexa voice-controlled assistant or Google Home, or controlled via Remote Services, can also be displayed fully by BMW Connected.
360° ELECTRIC: new charging cable, connected BMW i Wallbox
BMW i represents an all-embracing concept for sustainable and forward-looking mobility and has bundled together an extensive ecosystem of solutions for electric driving under the umbrella of 360° ELECTRIC. These products and services are designed to help make electric mobility in the new i8 Roadster a convenient and practical experience every day. It is supplied with a mode 2 charging cable as standard, enabling the high-voltage battery to be recharged from a standard domestic socket in under four-and-a-half hours. The new mode 3 cable can also be used to hook up the car to a public charging point for high-power charging.
The BMW i Wallbox makes home charging particularly easy and convenient. The latest version of the Wallbox allows the high-voltage battery to be recharged at a rate of up to 3.6 kW, meaning that charging can be completed in under three hours. The BMW i Wallbox Connect extends the functionality of the unique BMW Digital Charging Service to enable intelligent charging based around optimised cost efficiency or preferential use of self-generated solar power. There is additionally a facility for controlling the charging process from a smartphone via BMW Connected and for managing usage with an access card. Drivers have to register just once to gain access to the UK’s largest network of public charging stations via the ChargeNow card, which currently opens up an array of more than 5,500 charging points.