September 16, 2005 Porsche plans to launch a fourth version of the Cayenne Sports Utility Vehicle by the end of the decade. This vehicle will be powered by hybrid drive (gasoline engine and electric motor) being developed together with Volkswagen Group. This environmentally-friendly drive concept in the Cayenne will be based on a Full Hybrid Drive System, meaning that the vehicle will be powered by both a gasoline combustion engine and an electric motor able to operate both independently of one another and together in a joint process. A second clutch between the two drive units will allow the electric motor to operate fully independently whenever appropriate. The vehicle's power electronics, focusing on the position of the throttle, will determine the level of electrical energy to be supplied by the storage battery fitted at the rear of the vehicle to the electric motor in order to generate the drive power needed. Once the second clutch is closed, both the combustion engine and the electric motor are able to convey their power to the transmission. As soon as the electrical energy available has been consumed, the electric motor is automatically deactivated and the vehicle is driven entirely by the combustion engine.
These three different operating modes allow exclusive use of the electric motor not only when accelerating at a moderate speed from the traffic lights and in parking manoeuvres, but also when driving in residential areas with a speed limit of 30 km/h or 20 mph. Yet a further advantage is that the electric motor provides an additional brake effect, electrical energy generated in the process being stored in the battery and kept available for subsequent use when driving in the electric mode.
The hybrid concept chosen by Porsche combines a reduction of fuel consumption and emission-free motoring in the electric mode with the performance and driving dynamics typical of Porsche. The use of the electric motor decreases fuel consumption by approximately 15 per cent. The reduction of fuel consumption is the predominant factor in the decision for the Hybrid-Cayenne.