EDGE EP and M1 EP. Ok to mix?

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Sonata takes 5qts and the warranty period oci max 7500 miles. I was fortunate to purchase both on clearance for $2/qt at AZone (5w20). Cleared them out. EDGE=13qts M1=2qts I've mixed oils before but never cross-brand top tier syns that I plan to use for the full 7500 miles. I also know that the oil manufacturers say there is nothing to worry about. My plan is to use 4qts-EDGE/1qt-M1. Your thoughts...
 
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Why not just use Castrol Edge until it is gone, in the mean time get more M1 EP when it is on sale. I prefer to mix same brand and same type, M1 with M1 (EP or AFE or High Mileage ...), Mobil Super synthetic with Mobil Super synthetic, Castrol Edge with Castrol Edge ...
 
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Originally Posted By: HTSS_TR
Why not just use Castrol Edge until it is gone, in the mean time get more M1 EP when it is on sale.
+1
 

wemay

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Originally Posted By: HTSS_TR
Why not just use Castrol Edge until it is gone, in the mean time get more M1 EP when it is on sale. I prefer to mix same brand and same type, M1 with M1 (EP or AFE or High Mileage ...), Mobil Super synthetic with Mobil Super synthetic, Castrol Edge with Castrol Edge ...
Also a good idea.
 
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wemay

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Kuato, you know what? You're right. Although some have a preference to mix only the same brand etc., there is no issue mixing different ones as Mobil and Castrol have expressed. Enough frankenbrew mixes with excellent uoa on here prove this.
 
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Originally Posted By: bigt61
On a new car, I wouldn't mix. On an old beater, use what you have on hand.
Why would that matter. I suggest looking at the many frankenbrew used oil analysis we have here. You'll see that the oil holds up just fine,and in most cases the wear metals are lower,not that that in itself means a whole lot.
 
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Originally Posted By: Clevy
Originally Posted By: bigt61
On a new car, I wouldn't mix. On an old beater, use what you have on hand.
Why would that matter. I suggest looking at the many frankenbrew used oil analysis we have here. You'll see that the oil holds up just fine,and in most cases the wear metals are lower,not that that in itself means a whole lot.
Yeah, you can get away with it, but I personally wouldn't do it on a new car. Just like I wouldn't use Maxlife on a new car. "in most cases the wear metals are lower" - so just mix whatever you have lying around and your homebrew will produce better results than oil engineers who do it for a living? I don't think so. You can have a mulligan on that one if you want it.
 
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M1 says not to mix because of formulation differences. Like has been said, use the Edge, then later use straight M1.
 
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Originally Posted By: BobThe
When you switch brands at an OCI, you are basically mixing brands anyway since you can't get all of the old oil out anyway, right?
Right, and that's why your TBN typically takes a dive on the first OCI, presumably due to additive clash. Not that I think that it results in more engine wear or anything...
 
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Originally Posted By: BobThe
When you switch brands at an OCI, you are basically mixing brands anyway since you can't get all of the old oil out anyway, right?
In a way, this is true. MS5K has a sodium add pack, but M1 does not. I have done two 15K OCIs since using the last MS5K and sodium still registers in the UOAs. It is dropping each time, but it is still there, so it does take a while for dissimilar additive packs to "flush out".
 

wemay

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From Mobil1's FAQ section: Is it okay to mix conventional motor oil with Mobil 1™ motor oil? Yes. Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. But the superior performance of Mobil 1 will be reduced by diluting it. Of which the BOLD sounds like pure marketing, of coarse.
 
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The "compatibility test" is simply a test to ensure that nothing strange (like clumping, splitting, gelling) occurs, it's not testing the synergy of additives, nor even that two SL oils meet SL when mixed. In fact, the test is that they must not clump/split (like salad dressing) when mixed with 6 reference oils. Which is pretty close to certain but no guarantee that two different oils WON'T in a perfect storm. Most likely to be messed up are the cold weather performance. And in most people's starting temperatures, you are not going to see any issues with cold weather performance. If you need 5W performance, mixing two disparate 5Ws does not guarantee that you are getting it. And Quattro Pete's point is valid also.
 

wemay

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I also called Mobil1, Castrol and Valvoline. "You can mix all you want so long as the same viscosity is used" was the common theme. Well, luckily I found two more quarts of the EDGE EP. That makes an even 15 and affords me plenty of time to find the M1 EP while on sale. I won't need to mix anytime soon but I would have no issue doing so if need be.
 
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Originally Posted By: wemay
"You can mix all you want so long as the same viscosity is used" was the common theme.
Same viscosity? What does that even mean? Presumably they meant the same SAE viscosity grade, but as we know, each grade represents a range of various viscosities. The difference in viscosity between a "light" 30 and a "heavy" 30 could be more than between a "heavy" 20 and a "light" 30 sometimes.
 

wemay

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Originally Posted By: Quattro Pete
Originally Posted By: wemay
"You can mix all you want so long as the same viscosity is used" was the common theme.
Same viscosity? What does that even mean? Presumably they meant the same SAE viscosity grade, but as we know, each grade represents a range of various viscosities. The difference in viscosity between a "light" 30 and a "heavy" 30 could be more than between a "heavy" 20 and a "light" 30 sometimes.
I didn't even get into that with them because it wouldn't be worth the time but you're right, that is surely what was meant.
 
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Originally Posted By: Shannow
If you need 5W performance, mixing two disparate 5Ws does not guarantee that you are getting it.
I see you're still bringing up this unsubstantiated claim. Could you give us one proven example of two 5W oils that shouldn't be blended because the result will be a 10W oil?
 
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Originally Posted By: wemay
From Mobil1's FAQ section: Is it okay to mix conventional motor oil with Mobil 1™ motor oil? Yes. Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. But the superior performance of Mobil 1 will be reduced by diluting it. Of which the BOLD sounds like pure marketing, of coarse.
Sounds like common sense to me.
 
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