BMW's preliminary figures peg the new i8 at 70 miles per gallon equivalent (MPGe).
Inside, the i8 Roadster receives the latest version of iDrive with a choice of touch control on a free-standing 8.8-inch monitor or rotary control via a dial on the middle console. And like the coupe, the i8 Roadster boasts upward-swinging "gullwing" doors that further emphasize this a sports auto as not just another innovative vehicle, but rather art on wheels. BMW has been teasing this model for quite some time, but we finally get the chance to see it uncovered. The soft top folding into a covered compartment that replaces the coupe's rear seats. With an updated battery system, the hybrids now make 374 horsepower, up from the old i8's 357 hp.
The new BMW i8 Roadster accelerates from 0 to 100 km/h (62 mph) in 4.6 seconds and has a top speed of 250 km/h (155 mph). That said, for safety and longevity reasons, the usable capacity of only 9.4 kWh, which is enough to give the BMW i8 Coupe an electric range of 55 km (34 miles) in the NEDC cycle, while the slightly more cumbersome i8 Roadster can be driven in electric mode for up to 53 km (33 miles). Otherwise, the car's design will be familiar to current owners of the coupe - much of the changes to the Roadster are to its complex aluminium construction, to compensate for the loss of a rigid roof.
BMW has also had a fiddle with the glasshouse, beefing up the windscreen and quarter window and turning the rear window in to a deflector which can be raised or lowered wherever you have the roof. Unladen weight is 1,595 kg (3,516 lb), thanks to the use of the same LifeDrive vehicle architecture with aluminum chassis and carbon-fiber-reinforced plastic (CFRP) passenger cell.
It's been a great addition to the BMW range, now the i8 will welcome a second variant - a roadster. The battery pack is upgraded to 11.6kWh over 7.1kWh.
Both the 2019 i8 Roadster and the updated 2019 i8 Coupe will be available beginning spring 2018; stay tuned for pricing information.
The unchanged 170kW/320Nm 1.5-litre turbocharged three-cylinder petrol engine drives the rear wheels. When running on pure electric power, drive is sent to the front, though when both motors are running, power is sent to all-four-wheels. The i8 Roadster is set to go on sale in the United Kingdom in January, with a price of £124,730, while the updated i8 Coupe will cost £12,000 less.