Mix Oil Brands for Oil Change?

[fredfactory]

Originally Posted By: wemay
Originally Posted By: fredfactory

There are some additives that work on top of just about any existing oil mix when dosed in small amounts, possibly improving oil.


How do we define 'small amounts'. Some sumps hold 3qts, others 7, etc. I don't think we can have it both ways. If additive clash may cause an issue in mixed oils, the risk of adding stand alone additives may be just as questionable. It may also be that too much of an additive could cause problems. If you are against mixing oils, i cannot see how adding anything to it is different.


One assumes a reputable additive company like LiquiMoly will only provide additives that synergistically blend with most stuff in motor oil. There is a small chance they could be wrong, but they test their stuff. Small amounts means try a half-dose to a full-dose only.

 

[wemay]

Originally Posted By: fredfactory

assumes...
chance...
could be wrong...

 

[Dallas69]

Mixing helps clear space in the garage for more clearance oil.
Mixing makes the world go round.

 

[fredfactory]

Originally Posted By: wemay
Originally Posted By: fredfactory

assumes...
chance...
could be wrong...

I posted the chart below on another thread, from a tech paper which shows Moly plays well with PAO. Also, other tech papers have repeatedly said Moly rides on top of the ZDDP tribofilm, so its synergistic. Mixing may not be a great idea, since many chemicals are involved though. Just adding one thing, like Moly, or polymer Esters (another synergistic one) does the trick, keeps the "mixing" simple:

Note: The BN is hexagonal boron nitride, and notice the PAO+Moly line is high, which is good in the chart above (the higher the line the better).

 

[wemay]

Thanks for sharing that Fredfactory.

 

[Triple_Se7en]

Originally Posted By: bobbydavro
How do people really think they can improve an oil by randomly mixing two together ?!


It's just like medicine, fertilizer, dog food.....etc. You should NOT keep feeding your engine the same thing over & over again.

My next oil change will feature my vehicle getting a nine course meal. All half quarts mixed together from various oils I've used, being two of my vehicles take 4-1/2 quarts. So I always have a half-quart extra, which I put in a five quart container until full.

One oil may be rich in sodium -- another moly -- another boron......etc...etc. So never say blending oils doesn't help your engine. Because you might be dead wrong there.

 

[Shannow]

Originally Posted By: Triple_Se7en
So never say blending oils doesn't help your engine. Because you might be dead wrong there.


....might..."dead wrong" doesn't make "might" more effective.

Balance of probabilities is that things aren't going to be as good as either oil on their own.

Balance of probabilities is that there's going to be nothing really bad happens.Occasionally, bad things DO and are recorded to have happened.

Given all of the factors that go into a formulated oil
* basestocks
* VII
* PPD
* AW
* Detergents and Dispersents
* FM
* Anti-oxidants
* et al.

Your premise that you could randomly snag the ideal combination that improves on every aspect of either oil resulting in an improved outcome "might be" far fetched at the best.

 

[OVERKILL]

Originally Posted By: Shannow
Originally Posted By: Triple_Se7en
So never say blending oils doesn't help your engine. Because you might be dead wrong there.


....might..."dead wrong" doesn't make "might" more effective.

Balance of probabilities is that things aren't going to be as good as either oil on their own.

Balance of probabilities is that there's going to be nothing really bad happens.Occasionally, bad things DO and are recorded to have happened.

Given all of the factors that go into a formulated oil
* basestocks
* VII
* PPD
* AW
* Detergents and Dispersents
* FM
* Anti-oxidants
* et al.

Your premise that you could randomly snag the ideal combination that improves on every aspect of either oil resulting in an improved outcome "might be" far fetched at the best.


Naw man, it's like Young Einstein, you know, accidentally inventing atomic energy while trying to make beer right? LOL!

(in case you haven't seen the movie, Google is your friend).

 

[fredfactory]

Undeniable fact: Motor oil additives decompose at different rates over the course of an OCI. Therefore, that "carefully optimized" package that went in new oil is now down to, for example, 50% VII intact, 30% detergents intact, 40% anti-wear additives, etc., depending on the short tripping or heat cycles present, different in every vehicle.

Conclusion: Your new oil ceases to be new oil after a thousand miles or so, and degrades. Where's the magic balance then?

That said, you still don't want to clash with what's left in the oil, understood. So the strategy would be to worry less about mixing oil if its a 3,000 mile top-off, and try to use the same company's products, or use very select synergistic additives to increase oil capability.

 

[Shannow]

fredfactory,
you'll dind posts of mine where I've said exactly that and been poo-pooed as a fear monger.

What starts an OCI as a 0W almost certainly doesn't finish the OCI as a 0W.

ZDDP and MoDTC end up with a zinc phosphate and MoS2 glass on rubbing surfaces.

Peroxides, and sheared polymers are all part of the life of an OCI.

Starting the OCI with an upset balance doesn't make much sense.

 

[bobbydavro]

Originally Posted By: fredfactory
Undeniable fact: Motor oil additives decompose at different rates over the course of an OCI. Therefore, that "carefully optimized" package that went in new oil is now down to, for example, 50% VII intact, 30% detergents intact, 40% anti-wear additives, etc., depending on the short tripping or heat cycles present, different in every vehicle.

Conclusion: Your new oil ceases to be new oil after a thousand miles or so, and degrades. Where's the magic balance then?

That said, you still don't want to clash with what's left in the oil, understood. So the strategy would be to worry less about mixing oil if its a 3,000 mile top-off, and try to use the same company's products, or use very select synergistic additives to increase oil capability.


Aging is not mixing.

What are your thoughts on mixing calcium salyiclates with Magnesium phenates? How do you see Phoenlic Anti oxidants working with Moly Trimer? what about OCP VII performance when mixed with a High MW PAMA ppd at low temperatures?

I think you get the point?

 

[weasley]

Another factor to throw in here, is that additives 'metabolise' in use and become new molecules which are actually beneficial. For example the ZDDP 'decay' pathway includes a few active intermediates that help with the anti-wear film, but eventually you end up with a useless simple phosphate.

There are also synergistic interactions between additives, as well as detrimental ones.

Few people in this debate know about formulating engine oils. I am aware of one who does, and I do. It is difficult as a technologist to see so much assumption, hearsay and guesswork passed off and oft-repeated as fact.

To the general topic at hand, and in my PERSONAL opinion (informed by 23 years in the industry), mixing oils will rarely lead to a problem but will lead to sub-optimal performance. Most people will not have the means nor capability of noticing or determining the level of performance delivered by an oil, nor will they ever know how an engine would have performed if they had used a different oil instead. The only way to know what performance you are likely to get is to use a single oil - you at least know that this oil has proven performance in the specification tests it meets. A mix of two (or more) oils that meet the same spec will not necessarily meet that spec as a mixture - but nobody will ever test the mixtures in the specification testing so the whole thing becomes judgement and conjecture.

All this "I did this and it worked fine" experience can simply be boiled down to a no-harm outcome.

 

[Garak]

I think that's a very well reasoned point, Weasley. That's always been my concern, aside from my slightly humorous paranoia about mixing.

I'm not concerned about a blend of necessity or convenience. My outdoor power equipment rarely sticks to one viscosity or brand. However one has to be careful if one ever expects to stretch the limits of the lubricant - as you say, it will rarely lead to a problem but will lead to sub-optimal performance.

I don't want to be risking the 5w- or 0w- properties of an oil I'm using. In my climate, I choose a 5w-XX because of the weather, long before OEMs mandated it. I've also long known that the cold cranking properties of an oil diminish over time, so there's no point in making matters worse, as Shannow's evidence has shown time and time again. Additionally, companies like Mobil don't pro-rate their mileage warranties based upon mixing, nor do they share liability. M1 and M1 EP half and half don't get you a 12,500 mile guarantee. VWB and M1 mixed half and half don't get you a 3,000 mile Ashland warranty, with the rest of the 10,000 (pro-rated because of conventional Valvoline, of course

), covered by XOM.

There is some well reasoned mixing out there. And there are circumstances that warrant it. However, it's not a one-size-fits-all type thing.

Let's take the CATERHAM blend as an easy target. It works very well for a lot of people. CATERHAM has explained his reasons, and for certain circumstances, it makes sense. However, if I were up in the Arctic - or even in a very deep cold spell here - I'd be tempted to use one of the ingredients or the other, all alone, to deal with the cold, and perhaps TGMO 0w-20 in a lot of very short tripped vehicles in the ridiculous cold.

For my winters, if I wanted something 0w-XX, there are some decent choices, including TGMO, M1 0w-40, M1 AFE 0w-30, Petro-Canada Supreme Synthetic 0w-30, and Delvac Elite 222 0w-30, all depending upon the vehicle and the desired HTHS.

Of course, as I've said, I'm paranoid about blending. I can hardly bring myself to switch brands and viscosities from one OCI to the next. Note to all: I've got a few different jugs on the shelf that will likely be going into the F-150 over the next while before the Defy. If you don't hear from me for a time, I've probably had a stroke from switching from a QSGB 10w-30 to a 5w-30 and am temporarily incapacitated.

 

[OVERKILL]

Originally Posted By: bobbydavro

Aging is not mixing.

What are your thoughts on mixing calcium salyiclates with Magnesium phenates? How do you see Phoenlic Anti oxidants working with Moly Trimer? what about OCP VII performance when mixed with a High MW PAMA ppd at low temperatures?

I think you get the point?


And

Originally Posted By: weasley
Another factor to throw in here, is that additives 'metabolise' in use and become new molecules which are actually beneficial. For example the ZDDP 'decay' pathway includes a few active intermediates that help with the anti-wear film, but eventually you end up with a useless simple phosphate.

There are also synergistic interactions between additives, as well as detrimental ones.

Few people in this debate know about formulating engine oils. I am aware of one who does, and I do. It is difficult as a technologist to see so much assumption, hearsay and guesswork passed off and oft-repeated as fact.

To the general topic at hand, and in my PERSONAL opinion (informed by 23 years in the industry), mixing oils will rarely lead to a problem but will lead to sub-optimal performance. Most people will not have the means nor capability of noticing or determining the level of performance delivered by an oil, nor will they ever know how an engine would have performed if they had used a different oil instead. The only way to know what performance you are likely to get is to use a single oil - you at least know that this oil has proven performance in the specification tests it meets. A mix of two (or more) oils that meet the same spec will not necessarily meet that spec as a mixture - but nobody will ever test the mixtures in the specification testing so the whole thing becomes judgement and conjecture.

All this "I did this and it worked fine" experience can simply be boiled down to a no-harm outcome.


Great posts from both of you

It is nice to hear from people in the industry that provide legitimate testimony regarding the points a few of us are trying to get across.

Thank you

 

[quint]

what is the point being made, anyway? This thread seems to be a clash of guys in white lab coats holding clipboards sternly telling people how non-optimal it is to mix oils, versus the guy who has been mixing oils for years and years standing next to his fifteen year old Chevy with north of 300,000 miles on the odometer shrugging his shoulders while asking when the problems are going to start.

 

[kschachn]

Originally Posted By: Triple_Se7en
It's just like medicine, fertilizer, dog food.....etc. You should NOT keep feeding your engine the same thing over & over again.


It is? You mean my engine is just like my dog's metabolism?

I think you lost me there with that analogy.

 

[Clevy]

There are a couple of schools of thought and I feel both have some merit.

One is that using the exact same brand and grade of oil will maintain a more consistent anti wear layer.
The other is that using a different brand every interval will keep an engine cleaner because of the varying chemistry and new oil strips the previous oils anti-wear layer and applies its own regardless of brand.
So it's a toss up. I use a different brand every interval and my fleet of work vehicles all have in excess of 450k kms,and all city miles with the vans loaded almost to be point of pulling a wheelie and all still have the original gaskets(thanks motor oil saver) I see no real world evidence in my experience with my own vehicles.
I'm not saying that there isn't merit in the first example listed,just that in my experience it's not causing me any money in parts replacement.
No oil consumption to note either.

 

[fredfactory]

Originally Posted By: weasley
.......To the general topic at hand, and in my PERSONAL opinion (informed by 23 years in the industry), mixing oils will rarely lead to a problem but will lead to sub-optimal performance. Most people will not have the means nor capability of noticing or determining the level of performance delivered by an oil, nor will they ever know how an engine would have performed if they had used a different oil instead.......


True. Mixing is not a good idea. I'm not going to do it. Unless you're lucky, the mixture will probably not work as well.

 

[bobbydavro]

Originally Posted By: quint
what is the point being made, anyway? This thread seems to be a clash of guys in white lab coats holding clipboards sternly telling people how non-optimal it is to mix oils, versus the guy who has been mixing oils for years and years standing next to his fifteen year old Chevy with north of 300,000 miles on the odometer shrugging his shoulders while asking when the problems are going to start.


There's no issue with mixing. The issue I have is when people think blending two oils together can result in an oil that is better than either of the individual oils.

People with 'lab coats' are people who do this for a living with tools enabling real understanding of effects. 300,000 miles is pretty low compared to the equivalent testing that goes into an engine oil development.

Of course this is all useless if all that is required is mixing two off the shelf oils.

 

[wemay]

Originally Posted By: weasley
A mix of two (or more) oils that meet the same spec will not necessarily meet that spec as a mixture - but nobody will ever test the mixtures in the specification testing so the whole thing becomes judgement and conjecture.


The testing of every mixture possible would be impossible. Because those mixtures have not and will not be tested (of coarse), the outcome is uncertain. Therefor, assuring they meet any spec would be disingenuous.