No, I am not wrong on this. You are making the mistaken assumption that the value of UOA is all or nothing,
No, I think he's stating that for the use of determining engine WEAR, which a LOT of people on this site do, it is basically useless. And he would be correct in that statement.
AND you are mis-characterizing what I'm saying about UOA.
I think his statement is meant to broadly address those using $30.00 UOA's to find the "holy grail" of engine oil... Not to you specifically.
You are also overlooking the fact that I usually order particle counts with UOA.
You would be in the minority though. You are not the one being discussed, as your technique, since you use things like particle counts, steps outside the scope of the $30.00 UOA crowd....
I have never assumed, nor argued, that basic UOA is the be all and end all answer to what's happening in an engine. As I've already noted, you have to look at all the available information, in combination, before drawing any conclusions.
It is a good indication of contamination level, oil life depletion, and can act as a great indicator for things like coolant leaks, fuel dilution...etc.
Not so great for monitoring what people like to call "wear metals", because they may not be from wear.
Here's a hypo to consider: you do two UOAs, same vehicle, different oils, where virtually all the other variables remain the same, or very similar. On the first UOA, the Iron is normal. On the second, it shoots up to a much higher level. Now, off the bat, obviously this does not necessarily mean that the second oil is at fault. It could very well be other things. But nevertheless, the UOA provides the initial information that the owner can use to track down whether there is an issue, and if so, how to fix it.
This involves trending though. And the size of the spike would have to be factored into how one categorized the severity. If it was only a few PPM, then that falls into the category of noise.
Since we (not you, as you do particle counts) in general are dealing with particles less than 10 microns, as the poster above noted, then exactly what ARE we looking at? Not much. Any sort of large mechanical failure is going to create particles LARGER than 10 microns, which, like in BuickGN's example, DO NOT show up in your typically Blackstone UOA.
So here, you can have somebody thinking things are hunky-dory, when they are NOT, or could have somebody thinking their engine is coming apart when a pocket of deposits became uprooted, dissolved, and some <10 micron iron particles were put in suspension in the oil.
This is why Doug, and OTR truckers use UOA's to monitor CONTAMINATION levels, check for coolant leaks, and watch TAN and TBN to gauge their OCI's. That is the PURPOSE of this TOOL.
Perhaps you should consider the foolishness of condemning another poster, without having bothered to understand what that poster is saying. Please show me where I've said, ever, that I advocate relying solely upon low cost UOA results in drawing "meaningful conclusions".
But MANY on here DO. And unless you explicitly preface your posts with "I do particle counts too, and not just basic $30.00 UOA's", and refrain from citing UOA's in posts that ARE just basic UOA's and using them as EXAMPLES, like was done earlier, than you ARE enforcing that mindset. Obviously not intentionally, but without that sort of disclaimer, nobody KNOWS that you are not just doing the same thing they are.
Beyond that, what's your alternative? Fly blind until one day, your engine fails with no warning? You attack those of us who try to make some use of UOAs, but on the other hand, you don't offer anything that's any better.
Lets flip this over:
He could live contently in ignorant bliss doing regular OCI's and his engine will likely outlive the rest of his car.
Isn't the reason for specifically shopping for a vehicle that is known to be RELIABLE done to eliminate the headaches?
I will repeat: I use UOA, blotter cards, filter inspection, and the subjective signs my engines send, in order to determine whether further examination is necessary. And even then, I very well understand that there will be many things I can not determine from readily available sources of information.
So, what alternative do you propose for finding those larger particles that MAY not be detected in a low cost UOA???
Without a tear-down, you really can't. And that's the point I think. I know it sort of goes in concert with the whole maintenance OCD of those of us on this site, but really, if you think about how anal retentive you are with the maintenance of your car, then think about how many people rack up (in blissful ignorance I might add) ridiculous mileage without doing ANY of those things, I think perhaps you may be able to see the other side of this.....
Remember, OTR transport guys DO perform periodic tear-downs. They do them for a reason......