BMW's futuristic i8 supercar ran on a small three-cylinder engine plus electricity
With butterfly doors and a spaceship profile, the BMW i8 looked like a supercar, and it reached 100 km/h in 4.4 seconds. Under the rear sat a 1.5-litre three-cylinder petrol engine, the first ever fitted to a production BMW, helped by an electric motor driving the front wheels. Some of its engine sound was piped in artificially.
The car grew out of a 2009 concept called Vision EfficientDynamics, which paired a small three-cylinder diesel with two electric motors and had a drag coefficient of just 0.22. BMW confirmed in 2010 that a production version would be built in Leipzig, switched to petrol for the 2011 concept, and put that show car in the film Mission: Impossible – Ghost Protocol. Benoit Jacob designed the final version, unveiled at Frankfurt in 2013, borrowing heavily from a concept honouring the BMW M1, the company's previous mid-engined sports car.
The engineering chased lightness and balance. A carbon-fibre-reinforced plastic passenger cell kept weight to 1,485 kg, the battery ran down the car's central tunnel for a low centre of gravity, and mounting the engine and motor over the axles gave an even front-to-rear weight split. The small petrol engine produced 115 kW per litre, the highest specific output of any BMW Group engine. The i8 was also the first production car with laser headlights, which reach farther than LEDs.
Its green credentials depended on how it was driven. Europe's official test credited it with 2.1 litres per 100 km, but the original 7.1 kWh battery gave only about 24 km of electric driving on the American EPA cycle. The EPA estimated an average driver would cover 37 percent of miles on electricity, far below BMW's own i3 with range extender. A bigger 11.6 kWh battery arrived in 2018 alongside a roadster, yet the American electric range rose only from 15 to 18 miles.
Production ended on 11 June 2020 after 20,465 cars: 16,581 coupés and 3,884 roadsters. Along the way the i8 also served as the official safety car in the Formula E electric racing series.
Source: BMW i8
