used oil better than new?

[Pontual]

Originally Posted By: used_0il
Bedtime/fairytale;

Your new truck has an 8 liter oil sump capacity
and specifies 5W20 engine oil.

Your old truck with the same engine has a 6.5 liter
capacity and specifies 5W30 engine oil.

After 40,000 Km, your new truck consumes 1 liter of
oil per 1,000km, but uses 10 liters less fuel
in covering that distance repeatedly.

With your old truck, you would change the oil and filter
as per the olm at 13,000km, or about 2,000km per liter
of engine oil.

By the time the new truck arrives at 13,000km, you have
added 12 liters of oil.

Instead of changing the oil, you change just the filter
which holds one liter of oil, and add two liters of oil.

Your oil is never "that fresh" as to strip off, react with
or in other words, upset the chemical balance in the crankcase.

Now Farmer John doesn't know much about organic chemistry,
he just knows what works and doesn't ask why.


Well put! For Sure, thinner oils "are a great resouce conservation", you change a few quarts of gasoline saved and burn a few quarters of engine oil. It takes 160 times more petrol to produce one quart of engine oil than one quart of gasoline ...
That's what some shouldn't be "dividing and ...

 

[userfriendly]

Re Fairytale/Bedtime Story

There is more to the story than meets the eye.
Same for Farmer John's take.

The topic of used oil better than new can be
better addressed in Shannow's Ph vs TBN/TAN.

Why? Because the redundancy of fresh oil TBN
and other additives may.......

And I will leave off right there.

 

[Pontual]

Also a Fairy Tale from Noria?

Ester formation as part of oxidation process in hot parts of engine that burns alcohol (like street vehicles).

SCORE!!!

"Ester Formation
In the used oil environment, major reaction products for oxidation are ester. Some of the original FTIR peak height measurements utilized the ester band as the measurement of oxidation. These products are formed by both a primary free radical reaction mechanism (Baeyer-Villiger rearrangement6 - Reaction 14) and a secondary nonradical mechanism (esterification - Reaction 15).

Acid
ROOH + RC(O)R → ROH + RC(O)OR (14)
Alkyl Hydroperoxide Ketone Alcohol Ester

ROH + RC(O)OH → RC(O)OR+H2O (15)
Alcohol Carboxylic Acid Ester Water

The Baeyer-Villiger reaction typically occurs in the hot reaction zone, where the peroxide can readily decompose to its free radicals. It is catalyzed by the carboxylic acid previously formed in the oxidation cycle. The esterification reaction6 can occur in the hot zone; however, it can also occur in the colder zone."

In 6 years nobody thought of that. Huh, Molaekule?

Some people know better

http://www.machinerylubrication.com/Read/999/lubricants-oxidation

 

[Shannow]

Per the article that you linked, and cherry picked.

Quote:
Oxidation is the most predominant reaction experienced by a lubricant in service, accounting for significant lubricant problems. Oxidation is the major source for viscosity increase, varnish formation, sludge and sediment formation, additive depletion, base oil breakdown, filter plugging, loss in foam properties, acid number increase, rust and corrosion. Therefore, understanding and controlling oxidation is a major concern to the lubricant chemist.


It's a piece on varnish formation and ONE of the intermediary steps is AN esterification process...not the magical unicorn theory that you are advocating, in intermediary process in the varnish/sludge process...which Molakule mentioned a few posts up I believe.

You might want to read your linked article from one end to the other rather than grasping a work in the middle.

 

[Pontual]

That happens too, but it doesn't rule out the benefits of esterification in sump (you saw that?), until the oxidates concentration goes beyond a saturation level and start sludging, witch takes a long time. Why you guys keep searching the reading only what is convenient to your "that's impossible" short thinking ?

Haha

 

[userfriendly]

I thought that by then, the oil was far beyond it's
service life, additive package depleted and thickened
out of grade, or did I skip a page?

With the additive package gone, we have a snow ball
rolling down a mountain side out of control.

Esterification? What's that?
I thought we were talking about Easter vacation.

 

[userfriendly]

I change my engine oil twice a year.
Once in October and again just before EasterVacation.

 

[Garak]

Originally Posted By: Pontual
That happens too, but it doesn't rule out the benefits of esterification in sump....

However, do we know if these particular esters have any benefit whatsoever? Are they something that would ever be used as a base stock, or part of a base stock blend, and in what concentrations? Or, could they be counterproductive? That's what I'd fear.

I do know, however, that modern motor oil functioning is next to miraculous, in no small part due to the careful balancing act carried out by formulators, plus a little old fashioned luck.

 

[MolaKule]

Here is an excerpt from a White Paper that will appear on BITOG (Auto-Oxidation of Lubricants):

Quote:
The introduction of oxygen into oil is inevitable since oxygen comprises 21% of our atmosphere. Adding thermal energy, mechanical shear, and moisture to the lubricant froth only accelerates the degradation of engine oils.

Many good synthesized esters are introduced into the engine oil formulation, such as succinimide dispersants, ZDDP for anti-oxidation (AO) and anti-wear (AW), di-esters for seal swell, boron esters for AW and AO, and polyol esters for friction reduction and AW.

Some very bad esters can be found during the later portion of high temperature oxidation (> 150C), and only accelerates the transition of peroxides to hyper-peroxides and on to sludge. These transitional esters are short lived(1) and serve no useful purpose other than to promote auto-oxidation.

Sludge can be described as the terminal portion of oxidation and is a polymeric substance that increases the viscosity of the oil.

(1) Rosenberger, M., Oxidative degradation and stabilization of mineral oil based lubricant, in Chemistry and Technology of Lubricants


The polymeric substance known as sludge is the junk you will find in an overextended, oxidized lubricant.

So Ponty's hypothesis does not pass the scrutiny of organic chemistry research.

 

[turtlevette]

Originally Posted By: edhackett
This paper is often cited as proof that running your oil longer results in less wear. The paper does not say that at all, and that conclusion can not be drawn from the paper. The experimental design was not set up to test lower wear in an engine.

The two primary issues with the experimental design which prevent such conclusions from being drawn are:

1. The new oil was always run on a new shim. The aged oil was run on broken-in shims. Break-in wear of the shims was an uncontrolled variable.

all of the oils had long passed condemnation points for oxidative thickening, TBN, and TAN.

Ed


I'm not sure what a shim is. Why not run the used oil on a new shim to get apples to apples comparison. Of course a new part is going to wear more until the surfaces mate up.

If tan is at an unserviceable level, how can aw activate?

 

[Pontual]

Originally Posted By: MolaKule
Here is an excerpt from a White Paper that will appear on BITOG (Auto-Oxidation of Lubricants):

Quote:
The introduction of oxygen into oil is inevitable since oxygen comprises 21% of our atmosphere. Adding thermal energy, mechanical shear, and moisture to the lubricant froth only accelerates the degradation of engine oils.

Many good synthesized esters are introduced into the engine oil formulation, such as succinimide dispersants, ZDDP for anti-oxidation (AO) and anti-wear (AW), di-esters for seal swell, boron esters for AW and AO, and polyol esters for friction reduction and AW.

Some very bad esters can be found during the later portion of high temperature oxidation (> 150C), and only accelerates the transition of peroxides to hyper-peroxides and on to sludge. These transitional esters are short lived(1) and serve no useful purpose other than to promote auto-oxidation.

Sludge can be described as the terminal portion of oxidation and is a polymeric substance that increases the viscosity of the oil.

(1) Rosenberger, M., Oxidative degradation and stabilization of mineral oil based lubricant, in Chemistry and Technology of Lubricants


The polymeric substance known as sludge is the junk you will find in an overextended, oxidized lubricant.

So Ponty's hypothesis does not pass the scrutiny of organic chemistry research.




Hummm, bad esters eh?
Now those are made above 150C or 260+F. My oils don't get that hot ... Maybe in the ring pack ...

 

[MolaKule]

Yep bad esters and a bad hypothesis.