Originally Posted By: CATERHAM
Yes lots of 5w30 choice without having to go with the obsolete 10W-30 grade.
I disagree. True synthetic 10W-30 lubricants still have a place in high performance cars. A true synthetic 10W-30 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 10W-30 lubricant are well worth it.
1. Greater shear stability (My UOA samples of Amsoil 10W-30 ATM do not shear at all...not even 1%)
2. Lower NOACK (Amsoil 10W-30 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 10W-30 ATM Signature Series
Red Line 10W-30
Royal Purple 10W-30 API SL
Royal Purple 10W-30 HPS
Mobil 1 EP 10W-30 API SN