Braking energy can be utilised via the alternator on the electric motor. Experts call it recovery: the force acting on the brake pedal is determined via a control system. This influences the current intensity of the alternator supplying this braking energy to the battery (recovery). The disc brake system only engages on more severe braking manoeuvres.
In the Cayenne S Hybrid, Porsche uses the proven technology of the nickel-metal hydride battery. This gas-tight battery, which requires no maintenance, stores energy during driving. For example, for every 100 km driven, energy recovery saves 1 litre of fuel.
Power assistance and comfort systems have been converted to electric drive for the Cayenne S Hybrid. The AC compressor also takes its energy from the 288-Volt network of the NiMH battery. One advantage of the high voltage: the supply cables can be relatively small in cross-section, further saving weight. For the first time in this class of vehicle, Porsche is using electrohydraulic steering. This gives the precision typical of a Porsche, and – thanks to special functions such as stand-by mode for straight ahead driving – substantial fuel savings. In figures, this means a reduction of 93 %* in steering-specific energy consumption, compared with conventional hydraulic power steering in the New European Driving Cycle.
The great thing about the parallel full hybrid is that both the environment and the driver benefit. The electric motor does more than just replace the combustion engine: it also supports it (‘boosting’), further improving the acceleration and flexibility of the vehicle. Up to a speed of 130 km/h, the Hybrid Manager can switch off the combustion engine, which means that the vehicle – with no direct fuel consumption – can ‘glide’ almost silently on its way.
* The consumption values given are based on the combined cycle in the NEDC (New European Driving Cycle) to Euro 5 (715/2007/EC and 692/2008/EC). The figures do not relate to an individual vehicle but are intended solely as a means of comparing different vehicle types.
Fuel consumption/emissions** of the Cayenne S Hybrid: Urban in l/100 km 20 mpg; Extra urban in l/100 km 24 mpg; Combined in l/100 km ; CO2 emissions in g/km .