what oil gives the best coating at long time intervals?

[JHZR2]

Hi,

I am curious, what oil maintains the best and thickest coating on metal parts, especially contacting parts at long time periods? I have three thoughts:
1) A heavy dino oil, due to its inherently poorer flowability characteristics, as compared to synth oils would be best. Particularly an oil such as a 20w-50 which is quite heavy and would be relatively resistant to flow.
2) Any synthetic oil (heavier would still be better). As I understand it, synth oils tend to have a slight charge on the molecular endgroups, causing the oil to act like a large-scale surfactant, electrically attracting itself to the oppositely charged metallic engine surfaces. Since there is a layer of oil that is 'stuck' to the metallic surfaces, any synthetic, even a very light one, would easily build up a good hydrodynamic boundary because of the remaining oil.
3) The oil (synth or dino) with the best extreme pressure package, because no oil is going to coat beyond more than a few molecules thick if the engine has been sitting for a week or more.

Opinions? connents?
Thanks

JMH

 

[Patman]

For one, you want to choose an oil with moly in it, as the moly will coat the metal parts and leave a protective layer behind, so it's beneficial for infrequently driven cars.

 

[rugerman1]

Patman ,
Your next post is 5000!

Mark

 

[Al]

He's the "Administrator" he can just change the numbers

Sorry I hi-jacked the thread. I believe Esters cling to metals better than the PAO's and Dino oils. As was mentioned though the Moly is important as well as the ZDDP

[ March 14, 2003, 08:38 PM: Message edited by: Al ]

 

[TooSlick]

I'd run a synthetic diesel rated oil, something like Delvac 1, 5w-40, Redline 15w-40, or the Amsoil 10w-40. These are formulated with additional rust/corrosion inhibitors.

TooSlick

 

[satterfi]

According to this web site:

http://www.silkoleneoil.com/newpop4.htm

PAO's are nonpolar and "hopeless boundry lubricants".

I thought they were polar.

 

[MolaKule]

On the molecular level, esters give the best bonding and attraction to metals.

On the macroscopic level, there are two additives that can keep the oil on the surfaces:
1. A "clinger" called polyisobutylene (a synthetic hydrocarbon, usually in the form of an olefin copolymer)
2. A surfactant (surface-active-agent) of the alkylamine family of chemicals.

 

[Steve S]

I don't know stuff from Shinola only did chem 101 but from articles I've read pao is a copy of an oil molecule where as esters are something different as far as covalent charge or something.