Porsche model overview

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Porsche Traction Management

A New Generation of Four-Wheel Drive

Introducing the Cayenne model series, Porsche has succeeded in combining outstanding power and torque, sporting and agile handling as well as excellent driving dynamics with superior performance also off the beaten track. This is ensured to a large extent by Porsche Traction Management (PTM) featured as standard in the Cayenne, feeding 62 per cent of the engine's power to the rear and 38 per cent to the front wheels in the basic mode. Using a multiple-plate clutch operated by an electric motor and controlled electronically, the driver is able to vary the power split as required, if necessary even feeding 100 per cent of the engine's torque to the front or rear wheels. Porsche Traction Management can rightly be called an all-new generation of four-wheel drive with a significant influence on the dynamic performance of the Cayenne models. The map-controlled front-to-rear lock and the optionally available rear axle differential lock not only respond to lack of traction on the front or rear wheels, but also incorporate sensors within the PTM system measuring, say, the speed of the car, lateral acceleration, the steering angle and operation of the gas pedal, PTM thus determining the optimum lock on both axles and distributing the drive power actually required to the front and rear wheels. PTM may therefore be compared with an intelligently networked system providing superior driving stability and safe lane change behaviour both at high speeds and when driving on snow and ice at moderate speeds.

This innovation offers a whole range of outstanding results:

• Excellent driving stability and traction in all situations, regardless of the frictional coefficient

• Even more precise steering provided by the front-to-rear differential lock opening up to avoid any understeer effect

• Better control when driving to the limit ensured by the front-to-rear differential

• Enhanced directional stability and better road grip by operating the front-to-rear lock as required

• Maximum traction by increasing locking action before the wheels start to spin


Porsche Stability Management (PSM) featured as standard in the Cayenne models remains consistently in touch with PTM but only intervenes when the vehicle reaches its limits. Masterminding essential systems such as ABS, ASR and the ABD Automatic Brake Differential, PSM cuts in immediately under critical over- or understeer conditions and tells PTM to open up the locks in order to restabilise the vehicle by applying the brakes specifically on individual wheels.

A champion off the beaten track

The three versions of the Cayenne successfully combine outstanding performance on the road with equally outstanding offroad abilities. Indeed, they are already genuine masters off the beaten track in their “basic� configuration, intelligent four-wheel drive enabling the Cayennes to easily cross light terrain without any modification of the traction systems. On rough terrain the Porsche Traction System then uses the reduced-ratio gearbox featured as standard in the power divider. With its reduction ratio of 2.7:1, the reduction gearbox is ideal for even the most extreme offroad manoeuvres, easily handling steep gradients and, in particular, downhill passes. Activating the low-range mode by means of a toggle switch on the centre console, the driver can automatically prepare several control systems for offroad driving conditions: PTM switches over to the reduced ratio for offroad requirements and changes to a special offroad control map activating the differential locks, PSM responds by setting ABS and ABD to a special traction mode for offroad motoring, and the air suspension featured as standard in the Cayenne Turbo automatically lifts the entire vehicle up to its offroad level. Porsche is the first car maker to offer this combination of systems all controlled by one central offroad switch and thus significantly facilitating operation of these systems when driving under extreme conditions off the beaten track.