Quote:
Originally Posted by Spartarus
Heat plus air plus mechanical pressure, doesn't physically break moecules, but it accelerates degradation through oxidation. It doesn't need to be all that hot for that.
Oxidation is what I'm referring to when I say breaking down.
This happens in many ways, with heat and mechanical work, and especially with air entrainment.
This slowly turns your nice oil into a mixture of aldehydes, ketones, peroxides and carboxylic acids that don't do a great job lubricating things.
Oxidation in oils accelerates quadratically at temperatures above approximately 75 C. The rate doubles every 10 degrees. In theory, it will oxidize with ambient air, but not fast. Fast oxidation comes from rapid adiabatic heating of entrained air bubbles. Like when they get crushed between gear teeth.
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YIKES! ....... this is getting more complex than I figured it would ......
Here is an interesting read:
http://www.machinerylubrication.com/...tion-lubricant
So, I reckon that the transmission oil in a FR-S/BRZ can be "broken down" by the process of oxidation.
So, if the temperature of the oil exceeds a threshold point, the oxidation process can take place.
As @
Spartarus mentioned, "(I scraped it off the Internet) generally, oxidation will reduce the service life of a lubricant by half, for every 10 degrees C (18 degrees F) increase in fluid temperature above 60degrees C (140 degrees F)".
However, the manufacturers can add antioxidants and other compounds to slow down the process.
I want to thank @
Spartarus for his insightful and thorough contribution to the discussion.
What is the conclusion .......hell, I'm not sure .....
humfrz