Page 1 of 1 The BMW Group showcased its visions of future mobility in the shape of the BMW i3 Concept and BMW i8 Concept studies. Unveiled for the first time, these concept vehicles provide a glimpse of the first electrically powered production cars from the new BMW i sub-brand, due to be launched as the BMW i3 in 2013 and the BMW i8 in 2014.
BMW i stands for a new concept in sustainable mobility and a new approach to vehicle drive system design. The BMW i3 Concept and the BMW i8 Concept, with their highly innovative and efficient drive systems, demonstrate how future mobility can be both sustainable and dynamic. The BMW i3 Concept and BMW i8 Concept are two entirely different vehicles, and this is reflected in their different drive concepts. In both cases the design and configuration of the drive systems are dictated by the individual character of the vehicle and its intended area of application. While the BMW i3 Concept is an all-electric vehicle and therefore optimally equipped for operation around town, the plug-in hybrid BMW i8 Concept combines its electric motor with an internal combustion engine to deliver a high level of performance. The common link between the two vehicles is their electric motor, which marks a move away from exclusive reliance on an internal combustion engine. These cars are "born electric", and define a whole new concept in drive technology in their segment.
Whereas the BMW i3 Concept always drives on electric power, the i8 Concept combines the advantages of two different drive systems - an electric motor and an internal combustion engine. As a plug-in hybrid it offers the best of both worlds, combining maximum efficiency with maximum performance. A 0-100 km/h (62 mph) acceleration time of under five seconds, combined with fuel consumption in the European test cycle of less than 3 litres/100 km (approx. 94 mpg imp) and average real fuel consumption of between five and seven litres (40 - 56 mpg imp) even with a fast driving style are figures unrivalled by any conventional internal combustion-engined vehicle in this power class. Depending on charging habits and the nature of the route, it is even possible to improve on these figures. The secret is the intelligent configuration of the two drive units. In the BMW i8 Concept, the electric motor is not a secondary power source but an equal partner of the internal combustion engine. In this way the BMW i8 Concept achieves a new, ideal balance between the two drive units which results in an optimal combination of efficiency and dynamism.
The electric motor has been adopted from the BMW i3 Concept and modified for use in the BMW i8 Concept's hybrid power train. It drives the front axle, while a 164 kW/220 hp turbocharged three-cylinder petrol engine developing up to 300 Nm (221 lb-ft) of torque drives the rear axle. Together, the two drive units take the vehicle to a governed top speed of 250 km/h (155 mph). Like the electric motor, the 1.5-litre three-cylinder petrol engine was developed entirely in-house by the BMW Group and represents the latest state of the art in conventional engine design. The pairing of these two drive units in the BMW i8 Concept reflects the outstanding expertise of the BMW Group in the development of both engines and electric motors.
The energy supplied by the application-designed battery system installed between the front and rear axle modules to the electric motor at the front axle gives the BMW i8 Concept an all-electric driving range of approximately 35 kilometres (20 miles). The battery can be fully recharged in two hours at a standard power socket. The electric motor of the BMW i3 Concept has been specially modified for use in the plug-in hybrid power train of the BMW i8 Concept, i.e. for operation with a smaller battery pack and in conjunction with an internal combustion engine.
A highlight of the BMW i8 Concept is the high-voltage generator attached to the internal combustion engine, via which the internal combustion engine can generate power for recharging the batteries. This option is only used to increase the range of the vehicle while out on the road, and is not intended as a substitute for stationary recharging at an electric power socket.
Although the BMW i8 Concept has all-electric capability, the big attraction of this vehicle lies in the combination of the two different propulsion systems. The BMW i8 Concept combines the high-torque responsiveness of an electric motor with the power of an internal combustion engine, a field in which BMW has specialised for many decades. The BMW i8 Concept makes the most of the specific advantages of the two propulsion systems, which complement and support each other perfectly. The two power sources dovetail smoothly to compensate for any loss of power during gear changes. The combined result is that the BMW i8 Concept provides very dynamic acceleration performance across the entire road speed range.
All four wheels of the BMW i8 Concept can be driven at the same time, similarly to an all-wheel-drive vehicle. This solution combines the driving dynamics advantages of front-wheel drive, rear-wheel drive and all-wheel drive. An optimal drive configuration can therefore be provided to suit all driving situations.
When accelerating on dry roads, for example, maximum traction is available at all four wheels, resulting in better driving dynamics and driving enjoyment even when pushing the vehicle hard. In winter, too, the two separately driven axles provide benefits, the four intelligently driven wheels making for enhanced safety on slippery roads and keeping the vehicle moving under almost all winter conditions.
The fact that the electric motor is located at the front axle of the BMW i8 Concept optimises braking energy recuperation, since the front axle is where greater braking forces are developed due to the dynamic wheel load shift when decelerating. Whenever there is a chance to recuperate braking energy, intelligent driving dynamics systems make the most of it, taking into account traction conditions and driving situation, without compromising stability and dynamics. This allows very high levels of braking energy recuperation even in the wet or in snow. Depending on requirements, braking is initially provided by the recuperation function and only when more powerful braking is required is the conventional brake system engaged. Page 1 of 1