mixing oils can eat your engine?

[buster]

Noria.com

Quote:
Mixing oils with different additive packages is never recommended. Doing so could compromise the additive performance of both constituents, cause corrosion of component surfaces and lead to increased mechanical wear. Trending of some oil analysis properties also will be compromised.

In a pinch, if the oils are the same viscosity, you may be able to get away with mixing for a short time.

 

[buster]

Quote:
In general it is never a good idea to mix two different oils in any application. If this is unavoidable, there are two major concerns, specifically incompatibility between the base oil, and incompatibility between the additives.

From a base oil standpoint, there are usually no problems with mixing a PAO synthetic and a mineral oil since both are hydrocarbon based and chemically very similar. However, extreme caution should be used if the synthetic oil is non-hydrocarbon based.

As for additive incompatibility, the biggest danger is mixing oils with very different additive packages, particularly mixing those with acidic additives, such as most AW and EP oils, with oils containing alkaline additives commonly used in crankcase oils. In this case, mixing can result in a number of problems including additive drop out, loss of demulsibility, foaming problems and reduced oxidation stability.

The best approach is to select the appropriate lubricant for the application at hand and stick with it!

 

[buster]

Case closed.

 

[OVERKILL]

Originally Posted By: Capa

Your problem is that you keep in dealing with absolutes. While I may create a mix that is slightly inferior there is no doubt that I can create a mix that is slightly superior. What if my 5W-20 has sheared and I add a quart of 5W-30 to bring it back to an acceptable 20 weight level. Then, yes, I have created a superior oil given my specific situation. Pleas note that I am not saying that one should always mix a 20 weight with a 30 weight but there are scenarios where it MAY be beneficial. You mention specific testing and so I am really wondering how you feel about boutique oils that lack said certifications?


Unfortunately, since you screwed up the quotes, I'm unwilling to take the effort to dissect all of the points you made in response to mine. The bottom line is that you can claim that you've created a superior product, and trump up all the strawmen you want to support that premise, but until you have actual performance data, it is nothing more than a WAG. An educated WAG? Sure, I can cede that possibility, but it is not verified performance.

With respect to boutique lubricants I know that at least some of those manufacturers run their products through a myriad of OEM testing regiments and simply are unwilling to pay the price necessary for the approvals. That is, they validate the performance of the product by running the many tests that are available to formulators to meet a given performance level, they simply don't pay for the OEM approvals. So yes, to a degree you are dealing with a bit of an honour system, but there is no doubt that the performance of the blended lubricants is indeed verified, which makes it markedly different from just tossing some OTS oils together and assuming you've made a better product.

 

[Garak]

Originally Posted By: Cup of Joe
The bolded portion would suggest he had insider knowledge and that Mobil 1 had 0w-20 AND 0w-30 in production and then pulled them from the shelves to later sell them again in 2009. Perhaps my memory is a bit poor but I remember Mobil 1 0w-30 on the shelves continuously to the present day. Not in every store but available to the market.

In fairness, CATERHAM is in Canada. My familiarity with the M1 0w-XX products is minimal (all I know is that tig1 goes 10,000 miles with the 0w-20

), so I'm not sure what the history is here versus across the border.

As for Jay Leno, I had read that quote in print some time ago. He's as ineffectual a mechanic as he is a comedian.

 

[Garak]

Originally Posted By: Danh
1) Oil certifications require compatibility among oils
2) Since like forever, people have been topping up oil with brands different than used in the last oil change

That is true, and those are the two most important points. But, speaking of certifications, do not forget this:

I cannot take PYB SN/GF-5 5w-30 and Mobil Super 1000 SN/GF-5, mix them in equal parts, and market that as Garak's Special Blend with a Starburst and Donut on the bottle. Assuming SOPUS and XOM let me get away with it, I still have to get API approval, regardless of the fact that both products are approved and compatible.

 

[hemitruck]

a lot of opinions here, seemingly based on some good facts and research. i can tell you with out a doubt, that since i am not a chemist or chem engineer, i am not sure that i would want to run a "little of this and a little of that" so i just avoid the situation by not mixing.

 

[Capa]

Originally Posted By: hemitruck
a lot of opinions here, seemingly based on some good facts and research. i can tell you with out a doubt, that since i am not a chemist or chem engineer, i am not sure that i would want to run a "little of this and a little of that" so i just avoid the situation by not mixing.


But that is the point of some of us. None of us can avoid mixing because every time you change oil brands you are going to have a mix because at least 1/2 a quart of the old oil is still in. The only way you avoid this scenario is to stick with the same brand for life and, yet, you still mixed because more than likely the factory fill was different from what you are currently using. Don't fall for the chemistry FUD.

This back and forth reminds me of the thin vs thick oil debate. The thick group always had the 800 lb gorilla in the room---the fact that so many US and Japanese vehicles run on thin oils were eclipsing 200-000-300,000 miles. It is the same here. Except unlike thin oils that have only been around for a little over a decade, people have been mixing oils for 40, 50, 60 years with absolutely no ill effects. To be fair, most of the anti-mixers acknowledge that mixing oils isn't detrimental to the engine, which is an absolutely untenable position.

 

[OVERKILL]

Originally Posted By: Capa
Except unlike thin oils that have only been around for a little over a decade, people have been mixing oils for 40, 50, 60 years with absolutely no ill effects.


We don't really know if there have been ill effects or not. If the reduction was simply in deposit control, it isn't something the average person is going to know. Same with reduction in lubricant life, particularly with the short intervals that most run. There are all kinds of negatives that can potentially result from mixing that aren't going to be observable without controlled testing. This is very much reflected in the quotes from the oil manufacturers who basically say that while oils are compatible, you are best to run a particular lubricant by itself to achieve the full advantages of the formulation. Yes, there will always be some trace amount from a previous fill, and that is acknowledged, however a 1/2L of "a little bit of this and a little bit of that" mixed in with, in my case 6 or 7L of fresh oil of the same oil is a far cry from purposely blending say 3L of one oil with 4L of another.

Quote:
To be fair, most of the anti-mixers acknowledge that mixing oils isn't detrimental to the engine, which is an absolutely untenable position.


Exactly. Nobody is crying catastrophic engine failure here. Simply that you may impact the performance of the lubricant in a certain area or areas by intentionally blending it with another. And the only way to know what has or has not been compromised would be to run it through the same testing regime employed by the manufacturers of the product when they blended it.

 

[JAG]

Capa, judging by your posts that I've randomly seen over the years, I'd rate your knowledge of motor oils as slightly better than the average guy off the street. Yet you argue with people about things who clearly know more about the matter than you do. You don't know knowledge sources here when you see it. Rather than me continuing to be irritated by your posts, I'm putting you on "Ignore". Yay, I won't have to see you write "FUD" again!

 

[JANDSZIRKLE]

after countless pages of debate...

i wonder what a voa or uoa of mixed odds and ends of oils would look like and what the testers comments would be of said concoction?

 

[Capa]

Originally Posted By: JAG
Capa, judging by your posts that I've randomly seen over the years, I'd rate your knowledge of motor oils as slightly better than the average guy off the street. Yet you argue with people about things who clearly know more about the matter than you do. You don't know knowledge sources here when you see it. Rather than me continuing to be irritated by your posts, I'm putting you on "Ignore". Yay, I won't have to see you write "FUD" again!


Jag, you are doing exactly what some here have accused Caterham of in belittling people and employing ad hominem arguments and, ironically, some of those people don't know more about oils than Caterham does. I have asked honest questions and have stated arguments that I believe have weight. While not many mix oils like Caterham, many do mix oils to get rid of excess inventory and I have been speaking for them.

 

[crinkles]

I Know certainly I will be mixing pennzoil blend, shell blend, M1 EP, and MSS in the coming years. I used to throw my stubs out (the bit left after an oil change) but figure I need to stretch my dollar a bit more. I regret not doing the same a few years ago when I had 6L frankenblend saved up.

 

[Swarmlord]

Originally Posted By: JAG
Capa, judging by your posts that I've randomly seen over the years, I'd rate your knowledge of motor oils as slightly better than the average guy off the street. Yet you argue with people about things who clearly know more about the matter than you do. You don't know knowledge sources here when you see it. Rather than me continuing to be irritated by your posts, I'm putting you on "Ignore". Yay, I won't have to see you write "FUD" again!


Because THAT is the mature thing to do in a discussion...

 

[MinamiKotaro]

I plan to go to Advance and buy one quart of every oil they have on the shelves to mix for the next OC in my Ion. Theoretically, I will have the best oil known to man ...

 

[JANDSZIRKLE]

Originally Posted By: MinamiKotaro
I plan to go to Advance and buy one quart of every oil they have on the shelves to mix for the next OC in my Ion. Theoretically, I will have the best oil known to man ...


x2.

theoretically it sounds right.... would have every additive known too man and may create one not yet known.... i kid....

truth be told, my father used too mix oils as if he were some secret biochemist when i was a kid. not once in all my youth did any of our family vehicles ever break down due too an oil related issue. and he would drive them till the wheels fell off so too speak. is it optimal these days? probably not. but im nowhere near an expert and am new here so will just say, its my 2 cents.

 

[panthermike]

Originally Posted By: ted s
mixing oils can eat your engine?


No. As already said here, mixing isn't ideal but certainly won't "eat" your engine. I don't typically mix oils but did on my current OCI to even out my stash. I surely won't lose any sleep over it, but won't make a habit of it either.

 

[Mr_Incredible]

This argument is reminding me of the argument...

"How many angels can dance on the head of a pin?"
"Blonde angels or brunette angels"
"Do angels even dance?"
"Baptist angels wouldn't. But if they DID dance..."
"What dance are they dancing?"

etc. etc. etc.

Or...

What is the air speed velocity of a fully laden swallow?

Or the REAL question that will confound Great Thinkers for centuries to come: David Lee Roth, or Sammy Hagar?