If anyone here visits the 6speedonline.com forum........here is a thread that is talking about this coolant issue:
Advantages of using porsche coolant over generic prestone? - 6speedonline.com Forums
This particular post on that thread is from the Technical Manager at Prestone:
Hi,
I am the Technical Manager for Prestone coolants. Our all makes, all models coolant is compatible with your factory fill and will not change the color of your current coolant. I looked up the specs for the ELF factory fill, it is a OAT (Organic Acid technology) long life coolant exactly like the Prestone product I am recommending. Our product meets or exceeds all ASTM standards that Porsche requires. You can get it anywhere for around 10$ for premixed 50/50 and 12.50 for concentrate. If you do buy concentrate, make sure to only mix it with demineralized or deionized water. If you have any other questions, please email me at
[email protected]