quote:
, I was looking for someone to explain the difference in lay man's terms. Right now I am using Amsoil Euro 5W-40 and from what I have been reading, it is a PAO base stock and very stable, but is there a better oil out there that it's base stock is derived from Esters or do I indeed have a good oil.
The Euro is a MAJORITY PAO with some TMP esters and an additive package.
If you go to the Interesting Articles Thread and search for Esters and PAO, there are some white papers on those topics as well.
Most full synthetic OTS PCMO oils today are majority PAO base oil with a minority of ester oil, say on a ratio of 85 to 15, respectively, and this will vary, depending on formulation philosophy, cost, and testing.
Now Redline's oil has a majority POE ester content.
The PAO serves as the main lubricity agent, and has high thermal and oxidation stability. Since PAO's have low miscibility (mixing or solving)potential due to their low chemical polarity, esters or other Group VI fluids are often used to increase the miscibility potential in order to solve the additives. As I stated in other threads, this is not so much a problem anymore since so many additives are in ester form, especially the dispersants. This negates having to use a high percentage of TMP or POE esters.
So why use esters at all? Esters improve the lubricity of the oil (reduce friction), swell the seals ever so slightly, improve fluid clarity and transparency because of their excellent solving capabilities, reduce the oxidation potential, reduce the volatility (reduce evaporation because of their thermal stabilities), lower the pour point below that which PAO's can offer, and increase the flash and fire point temp specs.
And for those who worry about full synthetic fluids damaging seals, stay tuned for the results of the tests that I have been conducting. You will be suprized at the results.
[ July 25, 2005, 05:58 PM: Message edited by: MolaKule ]