Originally Posted By: Shannow
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4147917/Re:_How_Realistic_Is_This_Theo#Post4147917
I've read that thread; participated in it.
I love how folks seem to forget how well I describe and account for stuff.
The general objection that Ed has is the thinks I don't take into account a residual effect. Hey, Ed - the clue phone is ringing ... it's for you. READ BELOW ...
Allow me to quote myself from the article I wrote: (I will underline for emphasis here)
https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/
"
It is in fact true to say that when you change oil frequently the UOA will exhibit a higher Fe wear metal count. There are two reasonable explanations to this phenomenon of elevated wear metals shortly after an OCI; residual oil and tribo-chemical interaction. When you change oil, no matter how much you “drip-drip-drip” the oil into the catch basin, there is always a moderate amount left in the engine. Ryan Stark of Blackstone estimates up to 20% of the old oil remains, more or less, depending upon the unique traits of each piece of equipment. So, when you begin your new OCI, you really are not starting at zero ppm. Additionally, there is indication that wear is elevated after each OCI because of chemical reactions of fresh additive packages. This claim is supported via an SAE study done by Ford and Conoco (ref #1) that surmised this very phenomenon, and additionally refers to a former study of the same conclusion predating it.
So, the reality is that we are seeing a combination of two phenomenon; one being the residual oil contribution and the other the chemical reactions. The elevated readings towards the beginning of an OCI are typically (for most engines) less than one point, representing tenths of change. I cannot deduce from this macro-data set what portion of wear is due to residual oil and what portion is due to chemical action, but to be honest it really does not matter, because it’s impossible to separate the two phenomena in real life, and they act together to produce a single result. Wear metals are factually elevated after an OCI due to chemistry and artificially inflated by residual metals; we cannot elude this truth."
Gosh - it seems to me that I clearly, articulately, fairly and openly acknowledged BOTH contributors. But hey, maybe I was too subtle?
What I claim is true:
- you cannot easily (if at all) knowingly separate the two contributors
- it does not matter, because the overall effect is what we have to deal with in reality
- my data proves two things to be true; shorter OCIs do not lower wear rates, whereas longer OCIs do lower wear rates
- the SAE study is a fair explanation as to why the TCB portion exists
Conveniently many folks forget what they read, and/or try to infer I missed something that I already discussed and explained.
I never claimed that TCB was a sole reason for the wear rate changes, any more than I never claimed that the fresh OCI fully strips the TCB down to "virgin metal" (as you implied that I stated, but I never actually made any claim of the sort). I frequently quoted the study, so that I would remove my influence and stick to the interpretation of the study's authors. When they said "remove", that is what I quoted. Don't blame me when all I was doing was directly quoting the origin of the statement.
I cannot stop you and others from either misinterpreting my information, nor maligning it (by error or intent).