ORIGINAL: blw
Red B- I have not seen any proof or claim that any synthetic oil protects like good old castor, newer European oils or not.
My observations may challenge that (to a degree).
The bottom line still is that synthetics burn to ash at lower temps than the point where castor provides better protection with 'varnish'. The varnish is protective whereas ash is not
There is a *very* interesting twist to this however -- which indicates that *some* synthetics may offer *more* protection than castor at high temperatures. It's not *just* the boiling-point that counts when you're examining the hi-temperature "last gasp" performance of an oil.
I use a blend of synthetic and castor.
So do I, but I'm considering revisiting this choice since I performed some pretty comprehensive testing.
Full review of my findings and video evidence to come (but not on RCU -- because after all, I may need to edit such an large and complex post at some stage and this seems to be a "luxury" withdrawn from my account).