best oil for hydrodynamic lubrication

[ausrex]

This is a question for the tech heads out there


After reading the wonderful tutorial "states of lubrication" it ocurred to me that I should be chasing an oil that provides the highest level of hydrodynamic lubrication for a given viscosity as the article states "...Now under perfect conditions this type of lubrication will not allow wear..."

My thinking is that a base oil that consistenty offers hydrodynamic lubrication in a given application should rely less on additives in order to provide boundary lubrication; or put simply, an oil that offer higher shear stability in the first place makes the "last line of defense" unnecessary.

Assuming this reasoning is correct, what oil brands/types promise the highest level of hydrodynamic lubrication?

 

[bruce381]

is oil vis related mostly not so much as to type
bruce

 

[MolaKule]

A good oil is a carefully balanced blend of based oils and additives.

Any modern oil today will provide sufficient lubrication in all three regimes. I prefer the thinnest synthetic oil that has shown good UOA numbers.

 

[Merkava_4]

Okay I'm going strictly from memory by what Bruce told me. Hydrodynamic wave formation is directly related to viscosity. An oil needs to be thick enough so that when the crankshaft starts to spin inside its main cap bearings, a wave will form and lift the crankshaft into suspension. I can see it happening in my mind, but it's hard for me to put it into words.

When I think of hydrodynamic wave formation, I think of those hydroplane racing boats that skim across the top of the water at over a 100MPH. I think her name was Miss Budweiser.

 

[JohnBrowning]

All ester based oils will be supior in this reguard to any other base stock oil of simalar viscosity. Ester based oils will also usualy have a much higher HTHS then other lesser base stock's of the same or simalar viscosity.Now I am not saying you need to use an ester based oil in your daily driver. I am saying that ester based oils tend to have supior physical and chemical charteristics of as compared to other base stocks used in PCMO.

 

[buster]

Quote:

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A good oil is a carefully balanced blend of based oils and additives.

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Right. JB, you over generalize my friend. It's not that simple. Some esters suck for automotive applications and some compete with other antiwear additives on the surface. Tooslick's cake analogy is a good one. You can have too much of any one component. It's the complete blend that makes a good oil. Lots of research and a lot of time is spent on these things. This is why I generally am against adding additives to oils or obsessing over "moly" or "esters" as many people are. It's just not that simple

I know Amsoil uses 4-7 bases oils in some oils. It's getting the right balance that makes it great. This is something I've learned over the years reading articles and posts from mola/bruce etc.