FWIW, my dismally unscientific contribution here is that I switched to Redline 5w40 (mainly to try and protect the turbos better) from the dealer-provided Mobil 1 5w30 and I seemed to have gotten better temps, but only a few degrees difference. But, as the weather is fluctuating I need to see. I'll see how the Redline holds up this Summer.
My old Porsche mechanic heavily involved in racing indicated their data logging showed Redline dropped track temps when compared to Mobil 1. Course, he coulda been trying to sell me on the more expensive oil as I had an oil change coming up.
Different environment tho -- he was prolly referring to air cooled engines.
I have no affiliation with Redline. There is prolly better oil out there.
2007 335i Coupe Jet Black/Black, Premium, Sport, Satellite, Brushed Aluminum
Last edited by qroc; 03-16-2007 at 04:02 PM.
Reason: Forgot something