Originally Posted By: Audi Junkie
To clarify another thing, afaik, The USA fuels react poorly with the new VW 504/507 oils, which the spec looks great on paper, but have low additives and are other-than Groupe III.
It's pretty annoying to hear strident arguments that "VW engineers know best" and "you think you know better" and such. These arguments are driven by a lack of understanding of the specs and engines themselves, and a blind deference to mythical "VW engineers", whom are imagined to be all-knowing and all-seeing and have the 2nd or 3rd owners' interest in mind.
On the other hand, how do ANY of us know exactly what additives are now in play with the latest partially non-metal based additives, that don't appear in the VOA/UOA test regimens? How do we know what the REAL TBN is for instance, when we only see the metals and not the non-metal package to counter acid growth?
I think that you raise some logical questions, but I ALSO think that there are many of us "outsiders" who truly have no clue as to the effectiveness of the newer oils in this environment, other than what we see in VOA and UOA and it all looks like an "oh [censored]" moment because we are only seeing PART of the package of the new oils.
Until and unless we get very CLEAR and unambiguous actual measured wear patterns under comparative conditions, for 504 type oils vs. say, 502 oils....NONE of us is really any the wiser. And THAT is the incredibly frustrating thing for all of us.