Originally Posted By: pickled
Gosh dangit Mori don't make me break out the tiddly winks that I had to use back in the day when I was forced to take organic chemistry for 3 semesters. I think they cost me like $50 back in the 90's. I believe they tried to teach me something about a chair, a boat, aeromatics and something called chirality? There were a lot of good looking ladies in those classes so I didn't get much book learnin' done!
Seriously though I would estimate that the second you get some combustion byproducts in your oil you have some polarity introduced no matter what the base oil content or additives are (via oxidation, organic acid production and moisture inclusions). Oils blended with high levels of Overbased Calcium Sulfonate detergents will definitely exhibit more polarity with use than other less fortified oils. This would come from the formation of Calcium Oxides as the detergents react with iron molecules in the tribofilms. Most FM's have polar characteristics and most likely become more so as they break down. Remember you oil is slowly dying as soon as it is dumped down yee old fill hole...gosh that is a sad statement! Essentially I would be looking for a 10W40 group II+ diesel rated oil with a high TBN and that should be the optimal fill because it likely has lots of FM's and Overbased Calcium Sulfonate. The resident tribologists might have a lot more to add.
All granted, but all those non-desirable constituents add up! Thank you for pointing out the degradation of oil during use, which of course changes the composition continually. Yet the requirements for A-Rx to work have been stated:
- no PAO (unless it's 100% PAO -- which does not exist)
- no esters
- no polar ingredients
If these requirements cannot be reasonably met, what's a thinking person to conclude? The mind wonders!*
*Also may wander or even meander, Gary A.