"Chemical reaction" could be linked to anti-wear layer stripping ... who knows since there seems to be no real specific test evidence of that actually happening. I will say this, that the Ford Coyote 5.0L V8 engine used in the Mustang and F-150 trucks typically experience a ticking noise right after an oil change - even when the same exact oil has been used on the oil change. And typically the ticking will slowly go away as the oil gets more and more miles put on it. Then do another fresh oil change and bingo, the ticking shows back up again. But if an anti-friction/anti-wear additive (like Liqu-Moly Ceratec, ratio of only 150-300 ml in 8-10 qts of oil) is put in the engine the ticking almost instantly goes away. I've had long discussions about this phenomena on other chat boards, and the ticking seems to be directly related to the friction level of the oil. So in that case, it seems possible that the anti-wear layer on engine parts has somehow changed upon a fresh oil change (AW layer stripped by the new oil?), which changes the friction level enough between certain parts that causes the ticking to begin. Then add 150-300 ml Ceratec and the ticking instantly disappears. A very strange phenomena that's been going on since 2011 in the Coyote and nobody has 100% pinned it down to the actual cause.
Originally Posted by kschachn
Yes, I saw that later. One should also note that his article is really not about increased wear with new oil, that's only a topic he invokes during his discussion about oil analysis in general. And the idea of stripping the tribofilm layer is proposed as one mechanism for the higher iron counts, but he provides no real evidence that's what is happening. In fact he doesn't even make that statement, what he does say is: "Studies have shown that elevated wear levels after an oil change can be directly linked to chemical reactions of fresh additive packages." So if you use the same oil as you did the last time then this should not happen?
Originally Posted by ZeeOSix
^^^ Notice who wrote that Machinery Lubrication article.