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It seems that the Cayenne Petrol (Base, S, GTS, Turbo and Turbo S) is more different than we think compared to a Cayenne Diesel and Hybrid.  
The driveline differential for a Non Diesel Cayenne is apparently different from a Diesel Cayenne. Which one is better?     
Here's how Porsche describes them:     
For Cayenne/S, GTS, Turbo/S:   
Porsche Traction Management (PTM): active all-wheel drive with electronic controlled, map-controlled multi-plate clutch, automatic limited-slip differential (ABD) and traction-slip control (ASR)    
For Cayenne Diesel and Hybrid:   
Porsche Traction Management (PTM): permanent all-wheel drive with self-locking center differential, variable rear torque split    
Link below talks about driveline differential technologies.   Questions for technical gear heads  :  
1. Simple question: For those with a Catenne V6, Cayenne S, GTS, Turbo/S, can you lock your center and rear differential via the control knob?    
 2. Complex question: Which driveline differential technology is better, the Diesel or Petrol? The self-locking center differential technology of the Diesel appears to be old technology from my (non expert) research.     
3. Super complex question: is the presence of a self locking center diff (in the case of the Diesel) a core reason why PDCC is not offered on a Diesel vs a Non-Diesel? You can get PDCC only with non-diesel Cayenne's.     
Would appreciate your help and comments on the two differential technologies.