Base stock question(s)

[ccap41]

Sorry if there is an easy way to search for this but I didn't know how to make a short phrase for an accurate search here or on Google so I thought I'd just make a new topic.. If need be feel free to just send a link to a thread or page that has my answers.

Anywaaaaaay, I'm talking to some guy and we're discussing additives and whatnot of oil and I could have sworn I read that synthetic base's additives and conventional bases additives almost work opposites of each other because one's base is(for example 5w-30) 30wt and additives will give it the cold flow of the 5w and the other is a 5w and the additives give it the warm flow of a 30wt.

This conversation is with a man w/ runs strictly 30wt oil, hence the conversation... Haha

Am I completely wrong in remembering that? Does somebody have a link to "proof", if so?

 

[MolaKule]

Quote:
Anywaaaaaay, I'm talking to some guy and we're discussing additives and whatnot of oil and I could have sworn I read that synthetic base's additives and conventional bases additives almost work opposites of each other because one's base is(for example 5w-30) 30wt and additives will give it the cold flow of the 5w and the other is a 5w and the additives give it the warm flow of a 30wt.


Totally misinformed.

If you are discussing commercial oil additives, there are oil additives for majority Group II oils and there are additive packages for fully synthetic oils.



Recommend you read Motor Oil University 101 on the front page as it has been updated.

 

[ARCOgraphite]

OP may have read where synthetic multigrade 10w30 can be built from majority ISO68 PAO/AN and meet 10W with little VI and PPD.

Whereas a "cheap dino" 5w30 would be built from ISO 22, 32 Group I,II blend with high VM treat rate and moderate PPD wax inhibitor.

That works, except for the additive talk - though VM could be classed additive.

No?

 

[MolaKule]

It wasn't clear from the original post what the actual question might have been, so here is a further explanation:

The Performance Improvement package from commercial suppliers contains all the needed chemistry's for wear protection, friction reduction, corrosion inhibition, dispersancy, detergency, and agents to combat oxidation.

Viscosity Index Improvers (VII's) are added after the base oil/PI package is blended, because base oil viscosities and quality vary.

Whether the base oil(s) used are synthetic or conventional, Viscosity Index Improvers are used to arrive at a target viscosity.

Now if the base oil mix is primarily PAO's/esters, less VII's are needed simply because the base oil(s) have inherently higher Viscosity Indices.

Conversely, if the base oil mix is primarily conventional Group II, more VII's are needed simply because the base oil(s) have inherently lower Viscosity Indices.

Again, a rereading of Motor oil University 101 will help.

 

[y_p_w]

The difference between "conventional" and "synthetic" is somewhat blurred these days. It hasn't been mentioned in this thread yet, but one of the things that's important with certain base oils is seal swell additives.

I believe straight weight oils are defined as not containing any viscosity index improvers. However, they can be made with base oils that technically could meet multi-grade standards. Red Line says their 40wt race oil is technically a 15W-40.

Also - what is "cold flow" as a practical matter? 5W refers to cold cranking and pumping at -30ºC and -35ºC. If you're thinking of a morning temp of 60ºF, the 5W part may not correspond to a better flowing oil at those temps. I thought that the infamous "German Castrol" 0W-30 was thicker at such temps than a typical "conventional" 5W-30.

 

[MolaKule]

Quote:
It hasn't been mentioned in this thread yet, but one of the things that's important with certain base oils is seal swell additives.


That why the the PI has has to targeted to the mix of base oils.

 

[ccap41]

Thank you guys! I definitely have spent some time reading the Motor Oil Uivercity 101 and I kind of saw where I was getting things confused/remembering incorrectly.

What I think I was confusing was that as a conventional oil wears out it tends to thicken over time whereas a synthetic oil tends to shear and thin out when worn down. I think that was the "opposite" characteristic I as confusing this with.

 

[y_p_w]

Originally Posted By: ccap41
Thank you guys! I definitely have spent some time reading the Motor Oil Uivercity 101 and I kind of saw where I was getting things confused/remembering incorrectly.

What I think I was confusing was that as a conventional oil wears out it tends to thicken over time whereas a synthetic oil tends to shear and thin out when worn down. I think that was the "opposite" characteristic I as confusing this with.

That sounds more like a generality.

One of the more fascinating oils is Mobil 1 0W-40. The supposed mechanism for the API sequence tests was that it stayed in grade for the test by shearing down quickly to a 30 (which helped with fuel economy), but eventually thickened up to a 40 by the end of the test sequence. The original M1 0W-40 even carried the Energy Conserving label on the API donut, which was uncommon on XW-40 oils.

 

[Buhwheat]

Base stocks typically come in Group 1, 2, 3, 4, and 5.

Most motor oils are very highly refined Group 3, and enter a sub-category of this refinement.

This is brought to us by the hydrocracking process.

 

[kschachn]

Originally Posted By: Buhwheat
Base stocks typically come in Group 1, 2, 3, 4, and 5.

Most motor oils are very highly refined Group 3, and enter a sub-category of this refinement.

This is brought to us by the hydrocracking process.


So hydrocracking is just refining, Buhwehat?

 

[y_p_w]

Originally Posted By: kschachn
Originally Posted By: Buhwheat
Base stocks typically come in Group 1, 2, 3, 4, and 5.

Most motor oils are very highly refined Group 3, and enter a sub-category of this refinement.

This is brought to us by the hydrocracking process.


So hydrocracking is just refining, Buhwehat?

Yeah - that description sounded a bit generic.

At this point I thought that most base oils were group 2. It's also pretty common to combine different base oils to achieve certain goals. Wasn't a combination of PAO (group 4) and esters (in group 5) used to help achieve multi-grade properties?

 

[CR94]

Originally Posted By: ccap41
... I could have sworn I read that synthetic base's additives and conventional bases additives almost work opposites of each other because one's base is(for example 5w-30) 30wt and additives will give it the cold flow of the 5w and the other is a 5w and the additives give it the warm flow of a 30wt. ...
For both mineral oils and synthetics, your second scenario (i.e, thin base stock, with its thinning at high temperatures limited by additives) is closer to the truth than your other scenario, which is completely confused. Other than that, I think some answers are overly complicated and not relevant to your question, even though they're correct.