* Cayenne: 3.6L V6 (290 horsepower)
* Cayenne S: 4.8L V8 (385 horsepower)
* Cayenne Turbo: 4.8L V8 (500 horsepower)
It's important to note that these are just the base engine options. There were also several optional packages and upgrades available, which may have affected the engine specifications.
To determine the exact engine size of a specific 2008 Cayenne, you'd need to know its trim level or consult the vehicle's documentation.