The Cayenne's combination of precise balance and confidence can best be described as "sure-footed." This remarkable poise can be attributed, in part, to the revolutionary Porsche Stability Management (PSM) system.
PSM uses a series of sensors as well as information from the Porsche Traction Management System, to monitor direction, speed, yaw velocity and lateral acceleration. PSM then uses the sensor readings to calculate the actual direction of vehicle travel.
The system can reduce understeer caused by sudden steering inputs when changing lanes or negociating a rapid sequence of bends, as well as mitigate understeer encountered when entering a corner at speed, especially in low-grip conditions. If the Cayenne begins to oversteer or understeer, PSM applies selective braking on individual wheels to help keep the Cayenne on the desired cornering line. If braking alone isn't enough to maitain control, PSM then utilizes the engine management system to control engine output in order to stabilize the handling.
PSM also compensates for mid-corner changes in load resulting from deceleration or braking, and when accelerating with the rear wheels on different surfaces, it improves traction and keeps the Cayenne on course. Braking is stable in all types of weather, while braking distances are reduced to a minimum.
A PSM indicator on the instrument cluster displays the systems presence. Of course, PSM can be switched off and is re-activated by braking.