Stop Playing Chemist

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Originally Posted By: buster
Same brand, similar chemistry obviously. Should be common sense. Anything beyond that you're just guessing.


Even with the same brand you're still guessing, only its a more educated guess. About all you'll really know is the viscosity, from using a viscosity calculator, and maybe a increase in something like moly for example.

OTOH I think you might be able to create a better dino synthetic blend than you can buy, by mixing your own. Although proving it to a skeptic might be tough.
 
Don't we all mix oils, whether we want to or not, with each oil change? A small percentage of the old oil remains, perhaps a 1/4 of a quart or so.

I'm looking very forward to my blend of 4 quarts of 0W-20 and 1 quart of 0W-40 for my next OCI.
 
Originally Posted By: Capa
Don't we all mix oils, whether we want to or not, with each oil change? A small percentage of the old oil remains, perhaps a 1/4 of a quart or so.

I'm looking very forward to my blend of 4 quarts of 0W-20 and 1 quart of 0W-40 for my next OCI.

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Don't do it! The back tires may fall off your car!


Originally Posted By: demarpaint
Although proving it to a skeptic might be tough.

Very true. Even if half of the stuff argued about here could be proven, some still would not believe if it countered their opinions.

All of the feuds, this, thick vs thin, syn vs dino, they're all fueled on opinions. Not many here have the ability to prove much of any of their side of argument.

I do find it funny that while so many ask for facts, Caterham still gets singled out yet he advocates, knowing minimum oil pressure, a fact, gauges that give facts. A fact to him, as many would ask for proof of the conversation, is that he has spoken to the manufacturer and been given the ok to mix the two oils. I don't get it. Here is another fact, I used his idea and both of my engines are still running!
 
Compatibility is one, thing but whether it's optimal is another. I'm sure you read how detergents compete with anti wear additives and that it takes a balance to get it right. If you're changing chemistry it's possible you disrupt that and the oil isn't as good as it should be. That's just one possible example.

Quote:
Mobil 1 Extended Performance 5W-20 synthetic oil is made with a proprietary blend of high-performance synthetic base stocks fortified with a precisely balanced additive component system
 
Originally Posted By: buster
Compatibility is one, thing but whether it's optimal is another. I'm sure you read how detergents compete with anti wear additives and that it takes a balance to get it right. If you're changing chemistry it's possible you disrupt that and the oil isn't as good as it should be. That's just one possible example.

Quote:
Mobil 1 Extended Performance 5W-20 synthetic oil is made with a proprietary blend of high-performance synthetic base stocks fortified with a precisely balanced additive component system

That's just marketing fluff. All motor oils have "precisely balanced" additive packages.
All street oils must be miscible with each other.
Most oils have very similar additive chemistries.
All formulators will tell you that you can add their oils to other oils without issue.
So what's the concern about blending oils?
There may be some possible minor positive or negative synergies between the additives used, but since no formulator is concerned about it I'm not either.

There is a trend on BITOG to over emphasis the less than obvious differences between oil brands; that one brand favourite has something magical going on that we just don't know about and if you through in a quart of something else you'll totally screw it up. The reality is undoubtedly closer to at most a slight dilutive affect to your favourite oil. And that's what every formulator I know of will tell you if you ask.
 
Originally Posted By: CATERHAM
Originally Posted By: buster
Compatibility is one, thing but whether it's optimal is another. I'm sure you read how detergents compete with anti wear additives and that it takes a balance to get it right. If you're changing chemistry it's possible you disrupt that and the oil isn't as good as it should be. That's just one possible example.

Quote:
Mobil 1 Extended Performance 5W-20 synthetic oil is made with a proprietary blend of high-performance synthetic base stocks fortified with a precisely balanced additive component system

That's just marketing fluff. All motor oils have "precisely balanced" additive packages.
All street oils must be miscible with each other.
Most oils have very similar additive chemistries.
All formulators will tell you that you can add their oils to other oils without issue.
So what's the concern about blending oils?
There may be some possible minor positive or negative synergies between the additives used, but since no formulator is concerned about it I'm not either.

There is a trend on BITOG to over emphasis the less than obvious differences between oil brands; that one brand favourite has something magical going on that we just don't know about and if you through in a quart of something else you'll totally screw it up. The reality is undoubtedly closer to at most a slight dilutive affect to your favourite oil. And that's what every formulator I know of will tell you if you ask.


This.

lol@'precisely balanced' so suggestive yet so abstract. What balance are we even talking about? The balance between Ca and Mg? The balance between VII shear and oxidative oil thickening? The balance between production cost and standards satisfaction?

Too much FUD coming from the "authorities". All these apocalyptic doomsday scenarios of blown engines and violent chemical reactions.
Sorry, but I was never the type of person to be afraid of the "unknown" or to be blindly subordinate. I HAVE to know about it first, before I can be afraid of it or respect it. Nobody should be dumping random things into their crankcase (ie Lucas, Slick50 etc), just like no one should be dumping random things into their mouth, but to assert that I shall not add a determined measure of MoDTC, ZDDP or borate esters to my oil, simply due to not holding a certain professional title, is well beyond their scope of authority.

Are there no good cooks who aren't chefs? Are all chefs better skilled than non-chefs? Should a non-chef ever prepare food? How about butchers? Can I not butcher my own meat? I'm not a custodian, but I gotta keep my residence clean- can I? I'm not an accountant, but I do my own taxes.

If that bothers you, then all I can say it "Be afraid of the autodidacts, be very afraid!"
 
lol@^

Wrong.

It's not hard to understand. Just because oils are compatible, doesn't mean you should mix them.

Quote:
Regardless of the type of oil you choose to run, Speed and Glady agree that you should remain consistent with your brand choice. "The worst thing you can do to your motor is change your brand of oil regularly," says Speed.

"You shouldn't mix oil brands because each brand is typically formulated with a select balance of additive systems that are unique," adds Glady.

Different oils and lubricants have different additives that can, at the very least, compete with one another and in the worst case scenario cancel each other out. Remember when you drain the oil from your engine the internal components that were exposed to the additive package still have those additives on their surfaces.

Speed says, "Be consistent with a good quality brand, and change the filter regularly."
 
Quote:
I shall not add a determined measure of MoDTC, ZDDP or borate esters to my oil, simply due to not holding a certain professional title, is well beyond their scope of authority.


Most oils are using similar enough chemistry that compatibility isn't an issue and you can add whatever you want to the oil. But when you do, you no longer know what you are getting.

When you buy an oil, the only way to tell what you are getting is based on the specifications and product data sheet. So you do know what you're getting.

What you are suggesting is actually creating an unknown.

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BTW, no one said engines are going to blow up. That's absurd. Of course you can mix oils.
 
Originally Posted By: buster

Most oils are using similar enough chemistry that compatibility isn't an issue and you can add whatever you want to the oil. But when you do, you no longer know what you are getting.

When you buy an oil, the only way to tell what you are getting is based on the specifications and product data sheet. So you do know what you're getting.

What you are suggesting is actually creating an unknown.

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BTW, no one said engines are going to blow up. That's absurd. Of course you can mix oils.

Well said!
 
So, after using Pennzoil YB for 26 years, and, at the insistence of my father in law, switching to Castrol GTX for an oil change on all three of my cars; I can switch back to PYB and use the left over Castrol GTX for what gets burned in between oil changes?
 
Originally Posted By: buster

Quote:

"You shouldn't mix oil brands because each brand is typically formulated with a select balance of additive systems that are unique," adds Glady.

Different oils and lubricants have different additives that can, at the very least, compete with one another and in the worst case scenario cancel each other out.



I appreciate the excerpts sir.

But honestly, I would LOVE to hear a technical explanation of exactly which common additives will compete, how surface competition is bad, and how they "cancel" each other out, as well as details on exactly how this happens! Because without any further elaboration, it's only FUD. If branding is what differentiates incompatible oils, then let' drop some names and get to the bottom of who is formulating a non-standard product with the potential to damage an engine upon contact with a competitors product. It all lies in the details, my friends
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Originally Posted By: jrustles
I appreciate the excerpts sir.

But honestly, I would LOVE to hear a technical explanation of exactly which common additives will compete, how surface competition is bad, and how they "cancel" each other out, as well as details on exactly how this happens! Because without any further elaboration, it's only FUD. If branding is what differentiates incompatible oils, then let' drop some names and get to the bottom of who is formulating a non-standard product with the potential to damage an engine upon contact with a competitors product. It all lies in the details, my friends
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I don't think anyone said engines could be damaged. You seem to be up to no good...taking a position against an extreme one that you've made up. Not only that, but you say it's FUD unless someone spoon feeds you details. Doing some online searches for terms like "additive-additive interactions antagonism oil" will help you find some articles. Here is one:
http://www.stlehouston.com/2HoustonSTLE/2011-2012/Program/Lubricant Additives-Heverly-2012_2_8.pdf

Also base oil type affects a lot of additives based on the oil's solubility toward those additives. This then affects the additive's performance. One example is ZDDP in an ester vs ZDDP in PAO or Group 3.
 
Originally Posted By: d00df00d
Do you disagree that mixing oils introduces unknown variables?


No, I would agree with that statement. Whether the unknowns a cause for concern? Well that depends on who you ask. PCMO mixing wouldn't concern me too much. Blending Redline (API unapproved) and, say GC wouldn't concern me in the least.

Originally Posted By: JAG
Originally Posted By: jrustles
I appreciate the excerpts sir.

But honestly, I would LOVE to hear a technical explanation of exactly which common additives will compete, how surface competition is bad, and how they "cancel" each other out, as well as details on exactly how this happens! Because without any further elaboration, it's only FUD. If branding is what differentiates incompatible oils, then let' drop some names and get to the bottom of who is formulating a non-standard product with the potential to damage an engine upon contact with a competitors product. It all lies in the details, my friends
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You seem to be up to no good...taking a position against an extreme one that you've made up.


The people who ask questions, to some types of people, will always "be up to no good". I can't help you there. Appreciate the comment, though.

Quote:

Not only that, but you say it's FUD unless someone spoon feeds you details.

Look, I share what I know with others who ask with the hopes of helping them, and I ask questions of others who may know, when I don't. Is that unreasonable? If you don't have the answer, why reply? To call me a seedy troll? Let someone who actually knows the details, share if they feel so inclined.

If someone says "don't blend oils because they're precision mixtures", suddenly, I need to know what happens. Do boron and moly compete for surface area causing both to perform worse? Does Ca reduce the efficacy of ZDP? Does more ZDP deplete TBN faster?

Am I just asking too many questions and annoying everyone? I can stop.
 
Originally Posted By: jrustles
Originally Posted By: d00df00d
Do you disagree that mixing oils introduces unknown variables?


No, I would agree with that statement. Whether the unknowns a cause for concern? Well that depends on who you ask. PCMO mixing wouldn't concern me too much. Blending Redline (API unapproved) and, say GC wouldn't concern me in the least.

You're thinking "I haven't heard a clear story about what could go wrong, so I'm going to go ahead and do it."

Buster and others are saying "there's no benefit and some possible risk, so it's not worth gambling."

If you want to call that two sides of the same coin, I think we'll have to agree to disagree.
 
jrustles, I've posted multiple links in this thread already and am done replying to you after this post because of your attitude...not that mine is all that great either. Your questions themselves are not what's annoying to me.
 
Originally Posted By: jrustles
But honestly, I would LOVE to hear a technical explanation of exactly which common additives will compete, how surface competition is bad, and how they "cancel" each other out, as well as details on exactly how this happens! Because without any further elaboration, it's only FUD.

I don't have an exact technical explanation, but it is a little more than FUD. I don't see formulators making one oil with both types of common detergent packages just to make the claim it's got the most detergent. I don't see them dumping in moly willy nilly, either, or dumping in the ZDDP to within a hair of the limits.

As I've said before, guys like CATERHAM do reasoned blending with an established goal in mind. I have absolutely no issue with that. Guys like MolaKule have jobs because they are extraordinarily well educated on how to properly blend motor oils. And it's in no small part due to that expertise that we do have the freedom to do blending experiments without causing a catastrophe. If one wishes to adjust viscosity and VI, guys like CATERHAM know what they're doing. Although I can't speak for him, he's not intending to play chemist with the additive package and I know him to be very careful with what he mixes.

I just doubt that someone who decides they like the moly of PYB, the certifications of M1 0w-40, the POA of GC, the esters of Red Line, and the color of RP and then takes a bit of each and dumps it into his sump each OCI is doing himself any favours. I'm not of the opinion it would cause outright harm (unless the blend were terribly out of spec or something odd). I can't see it being optimal, though.

The requirement for SN/GF-5 oils (and earlier such requirements) to be miscible were not designed to be a license for backyard chemists. They were designed to ensure that a driver who is low a quart on his sump full of GTX 5w-30 wouldn't need to fear problems or experience problems by tossing in a litre of PYB 5w-30 or 10w-30 at the gas station for top up. If we think the API/ILSAC regime established miscibility guidelines to please us BITOGers, we're dreaming.
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