Quote:
Originally Posted by Suberman
I found this:
https://www.avl.com/c/document_libra...&groupId=10138
Apparently the issue is DI injectors breaking up fuel which then coats the combustion chamber (and intake valves ) with a thin layer of fuel which displaces lubricant. It seems to me it is a ring design and valve stem problem, not an oil problem. |
The article you quoted provides a good discussion of the subject and of course, their model for evaluation.
As Dennis has eluded, from time to some additional clarity can help keep a discussion on course!
As technology evolves the ability to measure, divide things into smaller and more precise slices and understanding what goes on ever keeps improving.
I find the fascination with UOA wear metals that vary by very low ppm values ( lets say <10-20 ppm, only as an example) to be a bit of a wonder? Folks would benefit from appreciating that every test procedure has an inherent measurement error that is determined by evaluating multiple results of a control sample independent of field samples. In addition to that you are trying to understand a system(oil/engine)that is also prone to large variations from sample to sample, for lots of reasons. So unless you see gross wear metals above recognized benchmark limits, you really should focus on trends established from many oil samples compared with a baseline for your particular engine. And you need at least 4-6 samples on one oil, (particularly at the beginning of the life of an engine when things can be changing a lot) to get any kind of a baseline of what is normal for a particular engine. And even that may not be enough!
So if folks want to debate the minutiae of small differences to help their learning about the subject, that's one thing. Unfortunately, using one or two UOA samplings to evaluate the value of one oil as compared to another has very low capability of telling folks what they think they are trying to learn.
But I'm not trying to start a debate, just sharing, in the hope that some background might provoke some thought towards clarity.
Time to go back to watching!