Originally Posted By: Shannow
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Now, back to the In field anaylsis that they did, with the actual engines, in the actual field....and your belief that the paper proves that the bench tests are proof of your theories...
Would you advise the operator of car B, monitoring his Fe, TAN, and TBN at 5,000 miles to push through to 15,000 miles ?
Why, or why not ?
Why did the total wear metals (Fe), drop in the OCIs past that point, if the technique is repeatable ?
If same engine, same oil is a repeatable combination, how does it change so markedly from one run to the next ?
I would not advise anyone what to do with those UOA results, because they are not, in my belief, "normal" UOA data. They are clearly abnormally high.
However, it has just occurred to me that you and I may have a VERY SUBSTANTIALLY DIFFERENT understanding of the UOA data from the TCB study.
First and foremost, I want to say that despite our tense differences, I'm going to lay aside the attitude and just ask questions, without any intent to trap you, tease you or belittle you. I want to ask fair questions here because I think I may have an understanding of WHY you and I see things differently. AND I ALSO WANT TO ADMIT THAT I DON'T HAVE A CLEAR ANSWER TO THE QUESTIONS I AM ABOUT TO ASK YOU. I am looking for your input, so as to understand where your point of view is at, and also that it might give me an epiphany into a new view I may have overlooked. If you can accept this, read on. If not, please just ignore the rest of this post.
I'd like to state that I see the lubes as a GF-3, GF-4, and (what will become a) GF-5. That's just for clarification of how I'll refer to them. I realize it was a prototype lube, but it's close to what we'd call it today. Please don't go after me for this; I realize it's not 100% accurate. We can also refer to them at lube I, II and III (choosing to use the tables as name-sake).
Q: What is your understanding of just how the oils were used, collected and subsequently studied? Please be specific; tell me what you think happened in terms of what is and is not present at the test rig and how it got there.
I ask because I am making presumptions that you may not be making. There is room for a lot of interpretation in some aspects of the methodology of the study.
The SAE study data clearly shows two phenomenons; that of higher wear at the front end of an OCI and that of falling wear rates as the OCI extends. They noted those things repeatedly. They do not acknowledge, but I certainly call into question, the magnitude of wear in their study; it is not "normal" by any means. However, at the end of their study, their wear rates were very realistic and totally in-line with what we see in the real world. So how does an oil go from being unrealistic to realistic?
Regarding the overall Fe wear from all the samples, where does the Fe ppm come from? Are the results of the Fe a view of the wear from the engine PRIOR to the rig test, or perhaps the Fe is a combination of 4.6L wear AND 2.0L cam wear, or is it only wear from the rig? IOW, at what point did the take the UOA ppm count? They actually don't say (or at least I don't see it; maybe I overlooked it). Did they pull the oil and then test it immediately for the data in your image above? Or did they run the oil in the rig and then UOA? Or, did they do both and then subtract out the 4.6L basis from the overall numbers?
I cannot understand how they got such high Fe ppm counts. They do say they use "new" cars, and as I discussed previously, I don't know what "new" means. New off the showroom floor, or new after they did a break-in cycle? The magnitude of such ultra-high Fe numbers at the front of the short OCIs makes me wonder how they got such giant metal numbers. Are we seeing a combination of "new" engine wear AND "new" lobe/shim wear?
As they stated, each oil type was only run in one car. The Phos levels of the GF-3, 4 and (soon to be ) 5 oils varies. Are we seeing a double hit of break-in, and with the lower phos "C" type oil is just more susceptible?
And as I said, despite the unworldly high Fe in the short OCI oils, the longer oils settle down in to totally believable numbers. The wear rates become "real" and totally echo my data.
I feel unable and uncomfortable in answering your question about oil B at 5k miles. I don't believe the testing represents typical UOA data; in fact I know it to be so. They have three UOAs; I have over 600 of that same engine series. They have an engineering sample set; I have a statistically solid macro data set. I don't trust their data to be applicable to real observations in the field; my is totally "normalized". I am, to be honest, unwilling to make a comment about the question you ask because I just don't think the UOA data is "real" in terms of what normal wear represents. I am not trying to be evasive; I just don't trust the data to be "normal" and I am not totally sure what all the UOA represents in terms of contribution to the Fe.
It appears to me that the GF-4 lube has an issue basically throughout the bulk of the testing. It's way higher than type I and III in wear rates. Why? I don't know and they don't say.
I make a distinction here; one I've brought up before. As I've said before, there is a difference between the phenomenons and the realities.
The SAE study shows that short OCIs have high wear, and longer OCIs will produce lower wear rates, BUT the magnitudes are unnatural at the front end.
My data shows these same two conditions, but over a HUGE SET OF ALL KINDS OF ENGINES from all manner of applications.
The correlation between studies is undeniable; those two phenomenons clearly exist in both. But I don't claim that their study is anything other than what they claim it was to prove. It shows how older oils have an ability to develop a more mature TCB, and that product contributes to lower wear rates. I offer their results as an explanation as to what I see in the field. However their data would imply that LOTS of wear is induced by an OCI, whereas I find no such reality. Frequent OCIs are not harmful at all to the engine; they just do not offer any wear reduction as some folks believe that "new" oil is "better" for wear. It is my belief that the UOA data comes from the 4.6L engines, and the other frictional and wear data comes from the 2.0L rig in the lab. But, I cannot for the life of me understand how they got such high wear metals in the type II oil. Was it ONLY the 4.6L wear, or a combo of the wear from both contributors (engine and rig)? It would have been foolish for them to use "new" engines; what self-respecting engineer in auto and lube industry does not expect break-in metals? (remember it was Ford and also Conoco in collaboration). Were they THAT stupid to use brand new engines and test them right from mile 1? Still that does not explain why oil II (GF-4) did so much worse in terms of wear data. Point being this: the two phenomenons were present in all three engines, but engine with oil II was much higher than the other two, and all three were higher than "normal" data would ever expect to see.
Here's what I think they did with the cars (not the rigs in the lab). Do you see it the same way?
Load in new oil and a filter, drive 3k miles, do a full O/FCI and use the oil as the 3k "sample".
Load in new oil and a filter, drive 5k miles, do a full O/FCI and use the oil as the 5k "sample".
Etc ..
But, is it possible that they did this:
Load in new oil and a filter, drive 3k miles, draw a sample of oil for the rig test but continue on to the next sample without an OCI?
Same at 5k miles and continue the OCI?
etc?
I don't think they did it the second way, BUT ...
how is it that engine II with oil II managed to have a 57ppm of Fe at 3k miles, but then jump to 155ppm at 5k, then only slightly lower at 120ppm at 7.5k, but then DROP like rock to 34ppm at 10k and 32ppm at 15k?
Either the engine was having a really bad month, or they collected oil in a manner with fused some metal counts together.
Engine II took off like a rocket in Fe wear at 5k miles, but by the end settled back down to "normal" wear rates, as did the other two. Engine two had a vicious spike in wear, but I'm not able to understand why that happened at "mid test".
Do you believe that it was one OCI sampled along the way for a total of 15k miles in the test, or successive OCIs for a total of 40,500 miles?
And why do ALL of them have unnaturally high metals?
Just asking; trying to understand where you are at on this.