Started New Thread Agreed...so I started a new thread in the Tires section... http://bmwcca.org/forum/showthread.php?t=7666 Freude am Fahren (und Bewegen das Thread)...
This thread was about oil change intervals D.B. Cooper! I can afford a BMW but that dosen't mean I throw money away!
Always add this read to threads regarding oil change intervals, i.e. bring the knowledge base up to the 21st century: http://papers.sae.org/2007-01-4133/
S50B30US with 128k, with regular oil changes at 5k with Mobil 1 10W-30 synthetic. Sees regular autocross and track usage.
Thankfully the major car makers all conduct extensive oil and durability testing to insure that their prescribed OCI is appropriate. That is why they specify the oil spec and viscosity that must be used. If in doubt a $25 UOA test will tell you if the oil is still serviceable.