Mixing different oils

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So for some reason the seal on my oil filter failed this morning and I lost about 6 qt's of oil in my driveway before I realized it. The filter and oil only have 3100 miles on it. I had another filter on hand so I changed it and topped off the oil. The sump was filled with Schaeffers 15w40 but I didn't have enough to refill with it and just used whatever I had at my house. So when I was refilling I used two qt's of schaeffers, 2 qt's of Case No. 1, and 3 qt's of Proline. They were all 15w40 though. So I am wondering if I should finish the OCI with this mix or go pick up 3 gallons of oil and do another oci.
 
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Originally Posted By: Rendezvous
So for some reason the seal on my oil filter failed this morning and I lost about 6 qt's of oil in my driveway before I realized it. The filter and oil only have 3100 miles on it. I had another filter on hand so I changed it and topped off the oil. The sump was filled with Schaeffers 15w40 but I didn't have enough to refill with it and just used whatever I had at my house. So when I was refilling I used two qt's of schaeffers, 2 qt's of Case No. 1, and 3 qt's of Proline. They were all 15w40 though. So I am wondering if I should finish the OCI with this mix or go pick up 3 gallons of oil and do another oci.
DUDE, post pictures of this "failed" filter! This needs investigated.
 
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Rendezvous

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Originally Posted By: NHGUY
That filter was on way too tight,or way too loose...
That would be incorrect.
 
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Sometimes the crimped edges on spin-on oil filters fail & leak. I've also heard of bad design or manufacturing of the rubber o-ring seal too. It happens, rare we hope. More to the topic: Mixing is OK if its an older car. More persnickety about newer cars, so the "rule" is: If the car is worth less than $6,000, mix to your heart's content.
 
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I will ask this.. How about mixing say Pennzoil PYB 10w30 with Pennzoil Ultra 10w30 ? I have read on here mixing within the same brand is a all right way to go.
 
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Don't stress about the mix. You won't find a really scientific study anywhere or an official statement for any automaker or oil maker that mixing is bad. The people the tell you mixing is a cardinal sin are basing it on pure opinions and no facts.
 
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Originally Posted By: ToadU
Don't stress about the mix. You won't find a really scientific study anywhere or an official statement for any automaker or oil maker that mixing is bad. The people the tell you mixing is a cardinal sin are basing it on pure opinions and no facts.
There HAVE from time to time been some monumental mixing failures, and they HAVE been researched scientifically and published, so I'm not sure where you can come up with the statement above (another "pure opinion/no facts" perhaps ???). Anyway, I've never suggested that it's a cardinal sin, but the Myagi defence "best defence in no be there" is the ultimate protection against the very rare times that negative interaction can occur. OP, chances are that all will be fine, nothing to worry about.
 
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Originally Posted By: Rendezvous
It is a 13 Ram 3500 6.7 if it makes a difference. Thanks for the responses.
A friend of mine had a 2010 had a f-350 with the 6.7l power stroke. He had a Napa filter on it and from what he told me he was driving down the road unloaded and the recess that the gasket sits in blew out. He said it was a perfect notch almost like it was cut. It ended up ruining the engine. Ford covered half a new engine cause the failure was an aftermarket part. I don't know if it was a defective filter or excessive engine pressure though.
 
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excess pressure should rip open the can of the filter though, it's the thinnest and with the largest area. The notch was likely cut: too much pressure when shaping the material upon manufacture
 
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I don't know how many samples of oil I've blended up in my time but I would guess it's in the tens of thousands. I have never, ever, ever come across an example where a commercial oil will be incompatible another commercial oil. I have had prototype gunk that has caused problems but stuff like this always gets weeded out early on in the commercialisation process. My advice is feel free to comingle till your heart's content... PS - By commercial oil I mean 'crankcase' oil. If you try to blend with crude oil, olive oil, Oil Of Ulay or rancid chip fat, you might get problems...
 
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Joe90_guy does this correlate to properties and test performance as well ? i.e. do two 0W oils from different manufacturers always give you a 0W ? A 0W40/0W20 blend always mean that the 30 ish oil that results is a 0W30 ? I'm of the position that the different blends while being compatible, miscible etc. can't guarantee the performance specs of the blend...a half concentration of additive (A), and a half concentration of additive (B) doesn't necessarily add back up to "1". But happy to learn...
 
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If you blend two oils of identical viscosity grade, then absolutely yes, you will get a mix that is the same (eg 0W20 + 0W20 = 0W20). If you blend two different oils but which share a similar 'end', then the similar 'end' will not change but the dissimilar end will (eg 0W20 + 0W40 = 0W30-ish and 0W40 + 10W40 = 5W40-ish). The 'ish' is there to convey that what you get depends on the ratio in which you comingle the oils. Obviously 99% 0W20 + 1% 0W40 will very likely result in a slightly heavier but still on-grade 0W20. Regarding additive packs, if you blend a 50:50 mix of one oil that contains 10% DI and another with 6% DI, you will end up with an oil containing 8% DI. This gets tricky because 50% API SL + 50% API SN doesn't give you 100% API SM (would that life was so simple!). So, no, performance doesn't automatically blend. Having said that, if you blend a OW20 GF-5 oil with a 5W20 GF-5 oil, then you will get something that very likely GF-5 performance (albeit not demonstrable because there are no specs for 2.5W20 oil).
 
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Originally Posted By: Joe90_guy
If you blend two oils of identical viscosity grade, then absolutely yes, you will get a mix that is the same (eg 0W20 + 0W20 = 0W20). If you blend two different oils but which share a similar 'end', then the similar 'end' will not change but the dissimilar end will (eg 0W20 + 0W40 = 0W30-ish and 0W40 + 10W40 = 5W40-ish).
So the CCS and MRV specs can be interpolated (give or take, I know) between disparate brands, of disparate chemistry...although as you pointed out, there are like 4 "brands" for want of a better word. I thought the non-linearity that was shown in the PDS of the additive suppliers couldn't guarantee that. Guess I've got some humble pie to start on.
 
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Just remember that viscosities of virtually any description (CCS, MRV, KV, HTHS. etc) blend logarithmically not linearly but in answer to your question yes... The viscometrics that blenders quote on PDSs will I am sure have been properly measured on a batch of oil but the reality is that all of these numbers will move up and down depending on individual base oil batches and slight difference in additives.
 
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Originally Posted By: Joe90_guy
I don't know how many samples of oil I've blended up in my time but I would guess it's in the tens of thousands. I have never, ever, ever come across an example where a commercial oil will be incompatible another commercial oil.
Seems like some time back in HDDO there was a problem with high ethylene OCP and high propylene OCP causing low temperature problems in used oil. Most commercial engine oils are approved for military use which requires compatibility.
 
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