Originally Posted by sloinker
I don't think anyone can actually know what percentage of ester is contained in Red Line. The SDS shows 99% non hazardous so it could be anywhere from 1%-99% Ester with PAO taking up the difference. What I consider a 100% synthetic oil, there are very few out there and they cost more. Who would have thought it? I'm guessing there is next to no ester/pao in most easily available, heavily marketed synthetic oils, especially those that cost the least. If there were significant quantities in any of the major brands you could be sure it would be shouted from the rooftops in their advertisements. The Casstrol you can pretty much count on being whatever is cheapest contained in the bottle, they probably buy Supertech in bulk and re-bottle it, possibly add some magnet dust as a special ingredient and for marketing.
Here's an SDS of which I speak.
https://w3apps.phillips66.com/NetMSDS/ViewPDF.aspx?fileName=829143&Language=EN&IssueDate=7%2f2%2f2015&SubFormat=USDS
See the MSDS snapshot I posted earlier. They HAVE had SDS sheets that showed ranges for actual base oils, but the more recent ones have become significantly more vague, despite the specs on the products remaining identical. So, based on that, I would assume the product hasn't changed, simply they've made the SDS's less "revealing".