The radical BMW i8 has been revealed in its final production form at the Frankfurt motor show.

The plug-in, mid-engined hybrid sports car is the sister car to the new BMW i3. The 4.7-metre-long i8 features the same unusual construction methods, using a carbonfibre-reinforced plastic (CFRP) bodyshell sitting on a welded aluminium chassis. 

BMW claims the i8 can hit 100kph from rest in just 4.4sec with both the engine and electric motor engaged. Top speed — achieved by the petrol engine alone — is 250kph. BMW says this performance is partly thanks to the i8’s relatively low weight of 1490kg and an aerodynamic bodyshell. 

BMW says the i8 can reach 121kph in its pure electric mode. Weight distribution is “almost exactly” 50 percent front, 50 percent rear. The car has three driving modes: Comfort, Sport and EcoPro. BMW claims a range of 499km in hybrid mode, or up to 35km on lithium ion battery power alone.The i8 has a 2+2 layout with the three-cylinder engine and generator mounted behind the rear seats, driving the rear wheels. The front wheels are driven by an electric motor and a two-speed automatic transmission, while the battery pack is stored in the centre tunnel, with a petrol tank under the rear jump seats.The i8’s complex, part-time all-wheel-drive transmission is also of interest because it uses BMW’s new turbocharged 1.5-litre, three-cylinder engine, which will feature in the Mk3 Mini and BMW 1-series. The version of this engine in the i8 develops a remarkable 228bhp, and its specific output of 151bhp per litre is said to be the highest of any production BMW engine to date. The petrol engine — which drives through a six-speed automatic gearbox — and electric motor combined produce peak outputs of 356bhp and 58.06kgm.