It's as if forums were made for discussion and learning. I understand I can search, because I do/have A LOT. But cars/motors change, certs/oils change so info changes.
Go to the MSDS for that particular oil. Look for the pour point and the flash point.
Most are around 230-240c which is well above my oil temps. But whats a good level for both?
Two of the most inconsequential attributes.
So what do you recommend looking at for high temp operation
That Castrol 0w30 you mention is SL.
An oil with an approval that demonstrates high temperature oxidation stability, as well as resistance to deposit formation, ring sticking and varnish. Something like an ACEA A3/B4 oil with Mercedes-Benz 229.5 or VW 502 00 approval. Or the Mobil 1 ESP also mentioned. That's one of the best oils avilable anywhere.
It's more effective/ efficient imo to ask specific things like I did vs going across 4 different old threads. If there's no rule against creating new threads, you could just ignore.
There's 24+ years of history. Formerly by previous forum owners, "Best Oil" threads were forbidden. We sometimes have fun with that.
I have found the newest M1 5W30 EP D1 / Gen 3 rated Synthetic oil to be surprisingly quiet in my otherwise noisy Hyundai Sonata - this could make for a good choice (don’t extend OCI beyond what your OM calls for).
What're your thoughts on QSUP?
Here's a few previous threads to get you started on this brand. Some are quite long and detailed.
fat shaming