bancu

On based on coolant temperature and fuel consumption...off in 15 seconds to 13 minutes.

"To cool the engine compartment the fans are switch on with the ignition OFF, depending on coolant temperature and the last driving cycle (map on fuel consumption). The switch-on threshold is between 90c (195f) and 93c (200f) and running time is between 15 seconds and a maximum of 13 minutes. Once fan run-on is concluded, the fans will not start again with "Engine OFF."

In the Cayenne Turbo, the electric coolant run-on pump, which provides cooling for the turbocharger (to prevent coking) is activated through this function.

ajauch

From observation of my CT, this is based on engine temp. When the car is cool, there isn't an audible fan run-on. However, after an extended run you can hear the fans run after shutdown.

Alex

Kaz

A method I've used on all the turbo cars I've ever owned is to ease up on the engine ten minutes or so before I reach my destination. Lots of engine idling while rolling, no high RPM engine loads etc. Never had a turbo failure and have gone well over 100K on former turbo cars that I've owned.

Brent 89-GT

The turbo bearings are still lubricated by oil. The water jacket around the bearings is used to control the oil temp at the bearings. Sounds like the CT went one step further and monitors temps after shutdown. From what has been posted I see that the CT manages the cool down for you.