quote:Good question! I've wondered the same thing. Adding to this; are there more base oils from slack wax than just XHVI? What percentage does Castrol use in their US Syntec? FWIW I believe Rotella 5w-40 WAS about 90%, but NOW I'm not sure. I'm really curious to find out which other oils use it?
can anyone give me a list of oils known to use slack wax?