First off, I'm glad this mistake happened. Nothing was harmed and I learned a lot as a result of digging into it.
Here is the first lab result with the mistake
I've been running Schaeffer 15w40 for the summer and this is my third extend drain on it. The last 5 analysis's were on this oil grade(previous was Schaeffer 5w40 and different operating parameters). So I was concerned and not sure what to make of the OXD and COX results in this last UOA to be significantly off trend. What confused me the most was the consistent correlation of OXD and COX in all the past analysis, and the significant change in COX in this analysis. I have a basic understanding off OXD, but up until I looked into it I was ignorant of what COX is. So I started digging.
I called Schaeffer first and asked them what they though of my results. I ended up talking to a competent lady who had operated the lab in schaeffer for 25 years. She was also confused by the sudden change in COX, even though she was not sure what COX was referring to. I did however learn that the condemnation limits for this oil were much higher per Scheaffer then what I had assumed (yes I know engine manufactures have there own limits). She stated Schaeffer wouldn't of flagged this oil unless viscosity @ 100c had reached 18.8 or OXD had reached 35. She explained that in CK-4 oils, OXD was less important.
Next I emailed my Lab, and my rep explained that COX is referring to carbolic acids, and gave me this link for further reading. https://www.machinerylubrication.com/Read/475/oil-breakdown
When asked what could of caused the major spike in COX, she eventually replied back with this:
"I was surprised by the jump in OXD and COX with the similar hours. Upon further investigation, I pulled the hard copy data for your engine and our team had not used the correct IR reference spectrum and I apologize for that. I had them rerun the IR using the Schaeffer 15W40 (2022) IR reference spectrum and the OXD and COX data is more on trend."
This was new to me! I had no idea a VOA of the oil was so important for accurate oxidization readings. Here is my corrected results.
Furthermore she also supplied me with this excellent guide on Oil Analysis - this is chock full of info that I expect pretty much everyone will find useful!
Here is the first lab result with the mistake
I've been running Schaeffer 15w40 for the summer and this is my third extend drain on it. The last 5 analysis's were on this oil grade(previous was Schaeffer 5w40 and different operating parameters). So I was concerned and not sure what to make of the OXD and COX results in this last UOA to be significantly off trend. What confused me the most was the consistent correlation of OXD and COX in all the past analysis, and the significant change in COX in this analysis. I have a basic understanding off OXD, but up until I looked into it I was ignorant of what COX is. So I started digging.
I called Schaeffer first and asked them what they though of my results. I ended up talking to a competent lady who had operated the lab in schaeffer for 25 years. She was also confused by the sudden change in COX, even though she was not sure what COX was referring to. I did however learn that the condemnation limits for this oil were much higher per Scheaffer then what I had assumed (yes I know engine manufactures have there own limits). She stated Schaeffer wouldn't of flagged this oil unless viscosity @ 100c had reached 18.8 or OXD had reached 35. She explained that in CK-4 oils, OXD was less important.
Next I emailed my Lab, and my rep explained that COX is referring to carbolic acids, and gave me this link for further reading. https://www.machinerylubrication.com/Read/475/oil-breakdown
When asked what could of caused the major spike in COX, she eventually replied back with this:
"I was surprised by the jump in OXD and COX with the similar hours. Upon further investigation, I pulled the hard copy data for your engine and our team had not used the correct IR reference spectrum and I apologize for that. I had them rerun the IR using the Schaeffer 15W40 (2022) IR reference spectrum and the OXD and COX data is more on trend."
This was new to me! I had no idea a VOA of the oil was so important for accurate oxidization readings. Here is my corrected results.
Furthermore she also supplied me with this excellent guide on Oil Analysis - this is chock full of info that I expect pretty much everyone will find useful!
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