I'd really like to know what Amsoil thinks about how their SS line would compare to equivalent Euro grade oils grade for grade. They'll never share that but it would be interesting.
There was an interview with one of Amsoil's reps a few months back. For some of their oils (OE/High Mileage etc.) they purchase generic additive packages and just blend them. For other oils like SS/Dominator, they customer develop/tweak formulations in-house. The SS line is their flagship product using some of the highest quality base oils available.
For example, SS 0w40 vs Euro 0w40. I'm willing to be the SS is as good or better than the Euro. The primary difference is likely the SA levels and HT/HS of some grades.
The European grades are actually restricted a bit compared to what they do with SS line.
You can see with their Euro 0w40 there is no moly and boron is less. That doesn't necessarily mean it's worse off, but due to SA they reduced some metallic additive levels for better or worse.
Between the Euro and SS 0w40 I'd go with the 0w40. Noack is better with the SS 0w40. The Amsoil IIIH results are just too good to ignore.
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