Ron:
A couple points in response. First, you can't generalize about "turbines" like that. I flew jets in the Marines for eight years. The oil required in our engines (turbines, of course) was MIL-L-23699. All the oils that met the spec were Group-V products. The Group-Is that you've fallen in love with here would have, at the engine temps we saw, been reduced to black goop in a matter of minutes.
Second, before you go congratulating Tom, as if he's agreeing with you, you need to read more carefully. He said, "Consistently, the Grp I based oils are much cleaner than Grp III or PAOs, in spite of the fact that they are not as oxidatively stable. The main reason is that Grp I is more polar due to its aromaticity and better at dissolving polymeric compounds before they can solidify into deposits. PAOs and Grp IIIs are utterly paraffinic and notorious for their poor solubility, which is why they are usually amended with esters or ANs." Yeah, everyone knows that Group-I is good for solubility, but it's awful for oxidation. Once again, you are focussing upon one isolated feature of a product (solvency) while ignoring all the other important other qualities (such as ability to resist breakdown, etc.). If Group-Is are so good where are all the SM rated, top quality motor oils today??? Please name some!
Third, Tom also said, "Our coking test is designed for developing lubricants for jet engines and extremely high temperature industrial applications, where it correlates well with the field. There is no such proven correlation in automotive oils, but the ability of the test to distinguish the varnish/carbon deposit forming tendencies of various base oils is interesting and consistent with theory.
I should also point out that while PAOs and Grp IIIs are deposit formers in thin film, high temperature environments, this does not mean that they will form deposits in your lower temperature car engine." Exactly how does this support your theory of Group-I superiority? Of course, you never defined the environment in which G-I is allegedly superior. History has proven that Group-I is not superior as to car engines and hot run turbines -- again, where are the Group-I SM products today? Again, name some, please!
Finally, you said, "I would suggest that conventional oils due to their higher solubility keep deposits in suspension better than synthetic oils. " If you really don't see the huge distinction between a fluid dissolving one thing and suspending another, then respectfully, you shouldn't be prognosticating here.
This board is not dominated by "groupthink". It's dominated by folks who refuse to accept unsupportable claims without challenge (and who can spot a troll when he appears...).
