Mixed Oil Debate

Interesting it would mention gelling. While I have dumped most of my "scraps" into my "lawn mower" jug and used this Frankenoil in my small engines for years, I do look for anything strange. Before using it I always give it a good shake. And I pour it into a clear measuring cup before it goes into the engine. I've never noticed anything unusual...no weird coloring, no clumping, no streaks or gelling. And this mixture has about everything in it...conventional, synthetic, various brands and just about any weight under 50.

When I change the oil in my small engines I always examine it. I never seen anything unusual in there as well....though I'm no expert.

Would I run this type of Frankenoil in one of my vehicles? No. In a lawn mower....especially one as old as mine? Sure.

As I mentioned earlier....I do have 2 quarts of Valvoline synthetic 0/20 and 2 quarts of Valvoline synthetic 5/30 that I accumulated over the last few months that I intend to use in my wife's Corolla. Same brand, both synthetic, both in the same family within the same brand...just different weights. I feel pretty comfortable about using it. What are your thoughts?

The most likely (and the probability is extremely low) interaction is something happening to the cold temperature characteristics, which is why the pour point is tested as part of the standard, because that's where negative interactions have happened in the past. With a lawnmower, that isn't going to be a concern, and you definitely don't need to worry about it meeting LL-01 or A40, so it's a pretty good application to use up spare product all things considered.
 
If you read the thread, an oil formulator recommended mixing two different oils to help clean piston rings. Which is of benefit to the engine, which is the question you asked.
I did read the thread and I also actually UNDERSTOOD it too and its not what's in question or even close.

Putting the claims aside ( that's a different subject) this is a blender talking about base stocks to make a custom oil from scratch ( which is what they do with a custom ad pack)

That's NOT the same as putting PUP and QS in magic bullet with a dash of #2 grease to make Frankenbrew.
 
As far as true mixing goes, It was a hit or miss affair over the decades.
Not directed at your claims or you but that's the point. There is no reliable verifiable proof that any of this mixing did anything a fresh oil change wouldn't accomplish with all the apothecary stuff.

Even in your case, it could just as easily be said that the current oil in your engine was either low ( can create issues) or partially consumed (in terms of service) and it was not the "mixing" just the restoration did the trick.

People putting "stuff" in a blender and then imagining "supernatural achievements" based on anecdotal observations simply is not supported by any legitimate proof so far that I personally have ever seen or heard of.

Right up there with rain makers and patent medicines.
 
In plain words, mixing oils together and looking at the final mix and saying it’s looks okay is different from whether the final mixture will still correspond to the specs and needs of the engine.
 
The most likely (and the probability is extremely low) interaction is something happening to the cold temperature characteristics, which is why the pour point is tested as part of the standard, because that's where negative interactions have happened in the past. With a lawnmower, that isn't going to be a concern, and you definitely don't need to worry about it meeting LL-01 or A40, so it's a pretty good application to use up spare product all things considered.
Thoughts on the Valvoline synthetic 0/20 and 5/30 being used in a vehicle? Being the same brand and type of oil...I never gave it a 2nd thought for using it in my wife's Corolla spec'd for 0/20 until I started reading this thread.
 
Thoughts on the Valvoline synthetic 0/20 and 5/30 being used in a vehicle? Being the same brand and type of oil...I never gave it a 2nd thought for using it in my wife's Corolla spec'd for 0/20 until I started reading this thread.
Far less likely to do strange things when it is the same brand of oil.

Why are you mixing them though? What's the intention?
 
Far less likely to do strange things when it is the same brand of oil.

Why are you mixing them though? What's the intention?
No intentions other than using perfectly good oil. I had accumulated 2 quarts of the 0/20 and 2 of 5/30 from OCs on various friends vehicles.

It's certainly not something I have to do
 
If mixing oils causes such a problem I would assume oil manufacturers request you drain 100% of the old oil before putting in the new oil. I have yet to see that recommendation in my 40 years.

Does API or other entities test for mixing oil brands/viscosities? No.
Is there a likely hood any ad-packs may be not as effective when mixed with other ad packs or base oils? Likely.
Is mixing engine oils going to cause catastrophic failure? I would say as long as the oils meet the requirements set forth by the engine manufacturer, then no.

Would I personally run a homebrew concoction on a regular basis? No
Would I use a different oil for top up if needed? Absolutely. I think having the right amount of oil is more important than running low on oil.
 
They are mixed with a group of reference oils to ensure they don't split or do anything unexpected. They are in no way tested to confirm they retain all of the same performance characteristics they had when initially tested.

The biggest risk from mixing is a potential significant impact on the Winter rating. That's the most likely characteristic to be affected.

In the past, some oils have used significantly different additive package chemistries, for example, Valvoline used sodium, while nobody else did. Currently, Ravenol uses Tungsten while other manufacturers use moly. I'm sure you can recall Castrol and Kendall using Titanium. Some will use tri-nuclear moly (Mobil/Shell) while others may use more traditional forms of moly that require a higher treatment rate to achieve the same effect. They may also use different types of VII polymers.

While the potential for significantly negative synergies is quite low, upsetting the carefully selected balance of additives, particularly when mixing oils from different vendors that use different chemistries is not going to result in an improvement in performance, you are essentially guaranteed to have made something worse but it's unlikely that you'd ever notice it or that it would be significant.

Edit: I see @kschachn beat me to this bit, so I'm essentially reiterating, lol.
+10 BITOG points for using synergy in a reply
 
I'm running a mix of leftover oils right now. Car only takes 4.25L and oil comes in 5L bottles, so every sixth oil change gets whatever is left over, assuming no need to top off between.
 
I did read the thread and I also actually UNDERSTOOD it too and its not what's in question or even close.

Putting the claims aside ( that's a different subjecnt) this is a blender talking about base stocks to make a custom oil from scratch ( which is what they do with a custom ad pack)

That's NOT the same as putting PUP and QS in magic bullet with a dash of #2 grease to make Frankenbrew.
Please calm down and read the link again, because it is not a blender making a custom oil from scratch, it is a blender answering the question of mixing two already formulated oils purchased off the shelf, Nulon 25W60 with Edge 10W30. He liked the idea and gave his reason, and also gave me his preferred ratio.


Originally Posted By: SR5
Joe, do you think a dash of something like this 25W-60 mixed in with a normal Group IiI synthetic would help clean stuck piston rings ? If so how much would you add ? 10% as a starting guess ? Would you add it to something very thin like Shell Helix Ultra 0W20 (GTL) or somthing with natural low volatility like Castrol Edge 10W30 (a ILSAC Group III) ?

SonofJoe:
Yes. There's just something about Bright Stock that's great for rings. I might go for 20% with the Group III 10W30. Don't think about any Italian Tune-up's with the mixed oil; just lots of steady driving and lots of 'sit & soak' time so that the aromatics can do their job. Obviously same rules as before; check your dip stick and at the first sign of black, change the oil.”


Anyway I was just trying to help, not argue, I’ll leave you to it now.

I also thought Joe’s points about mixing in the other linked thread above were very interesting. I learnt a lot from Joe, he was a great educator, shame he is not around any more.
 
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Now, the appearance that most SP/GF6 lubricants share additive technology may make mixing more desirable/palatable for many, but we should never consider the brew is better performing than the highest quality oil used in the mixture.
So, you are saying, "mixing yields unpredictable results", and at the same time also saying "the brew is no better than the individual oils"

Isn't that a conundrum of sorts? Is there any test data showing that mixes are no better than the single oil of the mix?
 
How did you wind up with the extra L ?
The multiple jugs were on my garage shelf, and not empty.
Farm equip and the vehicles used on the farm, don't always take a full jug on fills, etc.

It's a simple 50/50 mix of the two oils.
 
@Jimmy_Russels response to me above...

That's a red herring. It's incumbent upon the mixer to prove his concoction is superior to the formulated, tested, certified highest quality oil incorporated in the mix. Not the other way around.

And to be clear for all the extremist that say "nothing catastrophic occurred in my years of mixing" No one said there would be. All that's being shared is that mixing is not an avenue towards a better product.
 
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