DogWood

ciaka used " Mobil Delvac 1 full synthetic gear oil 75W-90 (direct cross reference to Shell TF0951 - factory fill oil) " when he did his, has a nicely written DIY thread on this site....

DogWood

Never mind -wrong transmission

ciaka

There were several folks who drove for 60k then sent their PDK fluid for analysis at blackstone labs. Results showed oil was barely affected and particulate was barely showing and about a third of the way of its use.
Even dealers have chimed in to say not necessary. It if is something an individual feels strongly about, they should plan on replacing that too at 60k. It is your car after all and only you will be financially responsible for it.
So take charge, make decision, stick with it and own it all the way, through good or bad.

I paid about $20 bucks per quart for Pensosin FFL3, at NAPA. They have most Porsche fluids and greases in stock, at price half or third of what you would pay at dealer, and it is identical stuff. Not close to it, similar. IDENTICAL.
Also available online, search and you will be rewarded. Do nothing and expect others to search, and you will be handed what they find only.
Takes 10 quarts to refill.