Tried this in the 944, if you have not tried it, take about 20 out of your wallet, clean your back side with it and discard, same feeling.
Red Line Synthetic Oil - WaterWetter® Coolant Additives
I need more data before I'm willing to believe that Mobil one ruins plastic internals yet is used worldwide in a myriad of engines and is recommended by Porsche itself. As for engine noises, people used to come to our shop and tell me the same thing about marvel mystery oil quieting their engines, I never tried that goop either (except maybe to fog a boat motor). Some improvements are like the medical placebo effect, they just feel better. I always think a car runs smoother and quicker right after an oil change and although that would make sense I'm sure the effect is more mental than real. My education in the shop equated to this: frequency of oil changes and filters keeps engines cleaner. In other words, I'd rather add another Mobil 1 and filter change each year than fork out more for oil and leave it in the pan longer, just my take. I sincerely doubt whatever did my 986 in would have been effected by a different manufacturers snake oil.