Originally Posted By: CATERHAM
Yes lots of 5w30 choice without having to go with the obsolete 10w30 grade.
I disagree. True synthetic 10w30 lubricants still have a place in high performance cars. A true synthetic 10w30 will flow very much the same as a petroleum base 5w30 @ 32*F and higher. If you have no need for cold flow performance under 32*F, then the two specs you gain with a 10w30 lubricant are well worth it.
1. Greater shear stability (My used oil analysis samples of Amsoil 10w30 ATM do not shear at all...not even 1%)
2. Lower NOACK (Amsoil 10w30 ATM NOACK is only 5.7%. I have very little oil collecting in the supercharger now compared to the "recommend" lubricant for this engine.)
Original Poster....
Choose a 100% true synthetic that contains NO refined petroleum for your high performance turbo application and sleep with ease at night. You will have zero issues.
Amsoil 10w30 ATM Signature Series
Red Line 10w30
Royal Purple 10w30 API SL
Royal Purple 10w30 HPS
Mobil 1 Extended Performance 10w30 API SN