BMW has revealed its new i8 roadster at the 2017 Los Angeles motor show, which will go on sale alongside an updated version of the two-plus-two i8 Coupe in Australia next year featuring an updated 275kW plug-in petrol-electric hybrid driveline.
The i8 roadster finally arrives more than five years after it was original unveiled as a concept car at the 2012 Beijing motor show and two years after the near production based version debuted at last year?s Consumer Electronics Show in Las Vegas.
Differentiating the roadster from the coupe is a newly-developed fabric roof that automatically stows underneath a panel integrated within the two buttresses behind the cabin at the press of a button.
The roof is claimed to open and close in just 15 seconds at speeds up to 50km/h so drivers don?t get caught out in the rain.
Although both the roadster and coupe receive a similar facelift, the open-top?version?deletes the rear side windows which are replaced by new black panels overlaid with aluminium look trims etched with the word ?Roadster?.
The chassis has been strengthened and the windscreen features a strengthened frame and beefed up quarter windows. The rear window, which doubles as a wind deflector, is also altered, allowing it to be closed or opened individually from the roof.
BMW says the inherent structural integrity of the i8?s carbon fibre reinforced plastic and aluminium structure has helped in reducing the weight gain for the new Roadster, which is claimed to tip the scales just 60kg over the facelifted Coupe at 1594kg.
The roadster makes further changes inside over its coupe sibling with the removal of the rear two pews, which makes way for a claimed 92-litres of oddment space in cubby holes integrated into the rear bulkhead.
The dashboard design has also been lightly updated for the i8 Roadster and facelifted i8 Coupe, with the latest version of BMW?s iDrive system now offering either touch control on a free standing 8.8-inch monitor or rotary control via a dial on the middle console featuring among other subtle changes.
BMW has also confirmed its new open top i brand model receives newly designed seats, an optional head up display unit as well a range of new trim options, including carbon fibre trim elements for the dashboard and ceramic controls within the centre console.
Power for the new i8 Roadster and facelifted i8 Coupe comes from is a reworked version of the plug-in petrol-electric hybrid driveline used by the existing i8 Coupe ? the LifeDrive architecture as it is?labelled by BMW.
A mid-mount 1.5-litre three-cylinder petrol engine sits behind the cabin and with an electric motor mounted within the front axle assembly and the i8 can provide either front-wheel drive when running on the electric motor or four-wheel drive with the petrol engine and electric motor working together.?
The lithium-ion battery has been revised and its cell capacity has risen from a previous 20Ah to 34Ah, with energy capacity increasing from 7.1kWh to 11.6kWh. BMW claims the new battery provides a range of 53km for the i8 Roadster and 55km for the facelifted i8 Coupe in front-wheel drive electric mode up to a limited speed of 120km/h on the European test cycle.?
The three-pot engine remains unchanged in terms of power output producing the same 170kW and 320Nm as before, with drive channelled through a six-speed automatic gearbox to the rear wheels. The electric motor, however, has been upgraded with an additional 9kW increasing its power reserves to 105kW, which is delivered together with the same 250Nm of torque of today?s i8 Coupe via a two-speed gearbox to the front wheels.
The combined result of both motors working harmoniously is 275kW and a theoretical maximum torque loading of 570Nm, although the latter is continually regulated dependent on grip and traction levels.? Five different driving modes are available: comfort, sport, and eco drive in hybrid mode and comfort and eco drive in electric mode.?
BMW claims a 0-100km/h time of 4.6sec for the new i8 Roadster, with the revised i8 Coupe?s time put at 4.4secs. Both possess a limited top speed of 250km/h.
Finally, BMW has included its latest 360? electric charging system provides 7.2kW charging and a claimed 80 per cent state of charge for the i8 Roadster and facelifted i8 Coupe in under three hours.
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