Just ordered me some DT40

[JayG]

I fat fingered the quote, sorry
fixed it

The point I was making is them saying you would get a 40% reduction in HP if you didn't flush first if certain oils were in there because the ring seals would leak

sounds like BS to me.
Of course, I could be wrong

BTW, on LN website they say
"LN Engineering, aside from offering many products and services for both aircooled and watercooled Porsche models, devotes considerable resources to continued research and development, and most recently, partnering with Raby Engine Development again to develop Porsche-model specific lubricants.*"
"*For Porsche approved lubricant we use and recommend Motul 8100 X-Cess 5w40."

See for yourself
http://lnengineering.com/products/lubricants/joe-gibbs-racing-dt40-full-synthetic-5w40-european-sports-car-oil-12-quarts.html

and further
WHICH MOTOR OIL DO I (CHARLES NAVARRO) USE?
For cars under warranty, we use primarily Motul 8100 X-Cess 5w40, which is still a mid-SAPS oil with higher Zn and P levels than the low or no-SAPS oils favored by manufacturers for emissions system protection. Both used oil analysis and physical engine teardowns have proven this lubricant to be a superior choice to Mobil 1. Although we are still fans of Brad Penn, outside of warranty, we recommend Joe Gibbs Racing lubricants due to how closely they have worked with Flat 6 Innovations and us in developing their oils for use in Porsche models.

http://lnengineering.com/resources/2014/02/28/frequently-asked-questions-about-motor-oils/