Due for it's full reveal on July 29, BMW today revealed in-depth details of it's lightweight, battery-powered i3 city car.
The BMW i3 is designed from the ground up to be powered by an electric drive system. Like the car’s unique vehicle architecture – based around the LifeDrive structure and its carbon-fibre-reinforced plastic (CFRP) passenger cell – the electric motor, power electronics and high-voltage lithium-ion battery have been developed and manufactured independently by the BMW Group under its BMW eDrive programme.
The use of lightweight CFRP for the passenger cell cancels out the extra weight contributed by the lithium-ion battery, while the low, central positioning of the battery pack enhances the car’s agility thanks to perfectly balanced 50 : 50 weight distribution. Additionally, the electric motor mounted in close proximity to the driven rear axle offers unique performance characteristics for this type of drive system as well as providing unbeatable traction.
The electric motor generates output of 125 kW/170 hp and peak torque of 250 Newton metres (184 lb-ft), which is on tap from the word go. The motor weighs just 50 kilograms and boasts power density and responsiveness unprecedented in the world of electric mobility. The specific construction of the hybrid synchronous electric motor, developed exclusively for the BMW i3, maintains a linear flow of power into the higher reaches of the rev range. The BMW i3 sprints from 0 to 60 km/h (37 mph) in a mere 3.7 seconds and 0 to 100 km/h (62 mph) in 7.2 seconds.
The single-pedal control concept in the BMW i3 – configured by the BMW Group’s drive system development engineers – also contributes to the engaging driving experience. Recuperation mode is activated the moment the driver takes his foot off the accelerator. The electric motor switches from drive to generator mode, feeding power into the lithium-ion battery. At the same time, it generates a precisely controllable braking effect. This recuperation is speed-sensitive, which means the car “coasts” with maximum efficiency at high speeds and generates a strong braking effect at low speeds.
The lithium-ion battery enables the BMW i3 to achieve a range of 130 to 160 kilometres (81 – 99 miles) in everyday driving. This rises by around 20 kilometres (12 miles) in ECO PRO mode and by the same distance again in ECO PRO+ mode. If desired, the BMW i3 is also available with a range-extender engine, which maintains the charge of the lithium-ion battery at a constant level while on the move as soon as it dips below a specified value. This role is performed by a 650cc two-cylinder petrol engine developing 25 kW/34 hp and mounted immediately adjacent to the electric motor above the rear axle. The range extender increases the car’s maximum range in day-to-day driving to around 300 kilometres (approx. 180 miles).