Mixing oil from the manufactures perspective

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1,007
Location
Oklahoma
I certainly believe it's not ideal to mix oils. What are your thoughts on these quotes taken directly from their websites?
Originally Posted By: Amsoil
Mixing AMSOIL motor oils with other oils, however, will shorten the oil’s life expectancy and reduce the performance benefits. AMSOIL does not support extended drain intervals where oils have been mixed.
Originally Posted By: Mobil 1
the superior performance of Mobil 1 will be reduced by diluting it.
Originally Posted By: Pennzoil
It is advisable that you use the same oil for top-ups if needed, thereby giving you the best protection from the oil that you have chosen.
 
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13,616
Location
Frisco, TX
Originally Posted By: dave1251
Why would blenders support mixing their products with a unknown quantity?
Exactly. They can't outright say "don't mix" because API-certification requires them to be mixable. They just don't want people playing home chemist and then trying to sue them when something goes wrong. And of course, they want you to keep buying their products so there's a slight scare tactic. On the contrary, other manufacturers actually tell you to blend. Red Line, Motul, etc. tell you to mix THEIR oils together to make the one you want.
 
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15,879
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NE,Ohio
they almost have to say that.. mixing m1 5w30 with dollar general 5w30 certainly would dilute the oil Then you have the fact that there are many different additive packages, mixing together may reduce the effectiveness.
 
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9,783
Location
Saskatoon canada
Originally Posted By: Rand
they almost have to say that.. mixing m1 5w30 with dollar general 5w30 certainly would dilute the oil Then you have the fact that there are many different additive packages, mixing together may reduce the effectiveness.
I hear this all the time yet the used oil analysis done on the various frankenbrews posted onsite show that the mixed oil,different brands and grades,performed just fine. In fact if you put any stock in the wear metal levels the frankenbrews tend to have lower wear metals. So yeah one might think mixing is a bad idea however the data proves otherwise.
 
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Maricopa Arizona
Originally Posted By: Clevy
Originally Posted By: Rand
they almost have to say that.. mixing m1 5w30 with dollar general 5w30 certainly would dilute the oil Then you have the fact that there are many different additive packages, mixing together may reduce the effectiveness.
I hear this all the time yet the used oil analysis done on the various frankenbrews posted onsite show that the mixed oil,different brands and grades,performed just fine. In fact if you put any stock in the wear metal levels the frankenbrews tend to have lower wear metals. So yeah one might think mixing is a bad idea however the data proves otherwise.
It all depends. Someone will see your last sentence and will deduce that mixing one quart of API certified oil with 3 quarts of Bullseye from 7-11 and considers this not to be a bad idea.
 
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1,250
Location
Oklahoma
The oil companies want you to use their oil as much as possible and therefore will always be against mixing their oil with another brand. Many of us here mix oils and have been doing so for decades. In fact, if you change oil brands after an oil change and then you have effectively mixed brands since there is really no reasonable way to remove 100% of the old oil. I'd estimate that anywhere between 10-20% of the old oil is still there.
 

BlueOvalFitter

Site Donor 2021
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Cajun Country, La.
I remember back in the day, around here, Chevron Supreme was almost equal to GC, as to being "THE" Holy Grail in oil. I would buy CS 10W30 and 5W30 and mix it with ST synthetic 10W30 and 5W30. Why? Because I thought I was getting the best of both worlds; a top notch dino along with some full synthetic added in.
 

CELICA_XX

Thread starter
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1,007
Location
Oklahoma
Originally Posted By: Capa
Many of us here mix oils and have been doing so for decades.
I'm not saying it will destroy an engine. I'm simply saying it's definitely not ideal, and I don't understand why this practice is so prevalent on an oil enthusiast forum.
 
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OH
OTOH, finished oils are a carefully balanced blend of basestocks, correction fluids and add packs. OTOH, we've seen very clean UOAs here of brews consisting of three different basestocks and three different add packs. IMHO, it's better to mix like with like, even for any needed adds. If you want a valid UOA for any given oil, you need to run that oil only for three consecutive OCIs. If you don't care about that, then I doubt that any mixing of any motor oils will do any harm. It might even do some good, although I doubt that.
 

BlueOvalFitter

Site Donor 2021
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9,516
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Cajun Country, La.
In the end, why is it even a bother if someone wants to mix oils? Are they smarter than the engineers? NO. Will it harm their engine? Probably not. Will they sleep better at night? Most likely. So, all in all, why should it matter? Unless it's a personal thing with the one/ones against it. shrug
 
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28,123
Location
Regina, Saskatchewan, Canada
Originally Posted By: CELICA_XX
I'm simply saying it's definitely not ideal, and I don't understand why this practice is so prevalent on an oil enthusiast forum.
Some people like to experiment, and I certainly understand that on an enthusiast forum. Personally, I despise mixing to the point that it's a phobia. Heck, I prefer to buy oils in large enough quantities to ensure I have the same batch number for a few successive oil changes. wink
 
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43,670
Location
'Stralia
Originally Posted By: CELICA_XX
I'm simply saying it's definitely not ideal, and I don't understand why this practice is so prevalent on an oil enthusiast forum.
From my perspective, when synthetics came out in Oz, they were (and are) expensive, and a few of us (pre-internet), reading the works of David Vizard started making syn blends...and nothing blew up that we could blame the oil for. Years ago here, there was debate on the synthetic content of blends, and people did it themselves to make a known quantity (synth wise). Other people like to do "stuff", and it makes them feel good...I don't "need" chainmail, but like to make it. my new laundry has a tile grout that I've engineered with 50% fly ash, and I'm playing with ash/granite/limestone "roman concrete" for an outdoors project this summer.
 
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