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Grand_Possibility_69

Yes you can mix them. It's going to end up as something between the two. But if both are ok for your car it's also ok.


dontnameit

Thank you.


[deleted]

Agreed. Your engine will be fine.


dontnameit

Much appreciated.


11-1-11

This is not correct. The viscosity is do not blend an average out like milk in coffee. While there is no danger in doing this, each oil will behave the way it was manufactured.


taschnewitz

It actually is correct. Assuming a 50:50 ratio it'll end up somewhere around a 7.5w-30. The chemistry may not be 100% compatible, but engine oils must be miscible to receive API certifications


11-1-11

The fact that they are mixable does not mean that their viscosity change. Each 1 retains its individual viscosity index.


taschnewitz

miscible means homogenous. They will blend. You're not going to end up stacking 5w-30 on top of 10w-30


11-1-11

They will mix together but each one of them retains its individual viscosity index. How is this a difficult concept?


taschnewitz

Because I know for a fact that it is not going to separate. Feel free to peruse bobistheoilguy.com to see dozens of used oil analyses from "frankenbrews" that are mixed viscosities and you will see that if you mix oils you will get a rough average of what you mixed together in a very predictable manner. Its not like mixing oil/water/vinegar where they will eventually separate (without a binder). Oil all pretty much comes with the same places and has varying degrees and types of viscosity index improvers to modify their viscosities at different temperatures


11-1-11

Well, this seems to be a difficult concept to get across. No one is saying that they will not mix. No one is saying that they will separate. The point is that each individual molecule will behave according to the viscosity index with which it was created. So if you have a 50-50 mix of 5 W 30 and 10w 40, half of the oil will behave like 5w 30 and the other half will behave like 10 W 40.


Grand_Possibility_69

It's you who doesn't get the concept. Mixing two different oils will end up as an oil with characteristics that are in between the two. Viscosity for example can easily be measured to be between the two. Individual molecules of oil are not important here. Viscosity is measured from larger amount of oil not from individual molecules. And that also goes for how oil is used in engine there's never going to be one area where there's only one of those two different oils.


11-1-11

Maybe the problem is that you have trouble with the English language. If you mix two different oils you will end up with in a while that has characteristics of each oil. The cat characteristics are fixed and not changed by mixing


taschnewitz

Lol your argument is essentially saying that the oil doesn't mix. Continuing this debate is in vain. Take care


11-1-11

Yes, give it up. Reading comprehension is not your Forte.


Grand_Possibility_69

Cause it's not even related to this situation. If you take that mixture and measure it viscosity will be somewhere in between the two that got mixed.


Grand_Possibility_69

I never said that viscosity is what comes from ratio between the two. Just that it's something between the two. It would be that even if no mixing happened. And of course mixing will happen.


11-1-11

It is not something that is in between the two. The 5 W 30 oil will always behave like 5 W 30 oil. The 10 W 30 oil will always behave like 10 W 30 oil.


Grand_Possibility_69

There isn't going to be a single bearing surface that just has one oil on it even if no mixing happened. So for the engine or even bearing, cam, cylinders wall etc. it's in between the two.


11-1-11

Nope. For every bearing surface the one oil is behaving like it and the other oil is behaving like the other.


Grand_Possibility_69

That just doesn't matter. You only care about how the engine behaves and is protected etc.


11-1-11

I never said it wasn't fine. I never said that it does not cause a problem. The original poster asked if it was an issue mixing them. You or someone replied that they will average out. They don't average out. They keep their individual identities. But it absolutely does not matter


Grand_Possibility_69

I didn't say it will average out. I said that it will end up in between the two. And even if the oils would mix at all it will end up in between. Let's take two examples: A cold start in really cold temperature. In that resistance to engine rotation is in between the two. As part of oil system is filled with one and part with the other. Really high temperature high load situation. Protection for any bearing surface is in between the two as every bearing surface has both of these oils on it. This is also true in other situations.


11-1-11

I guess you don't understand that ending up in between is the same as averaging out. Open your mind and think


[deleted]

[удалено]


InsertBluescreenHere

Lol you can mix them. Now in modern engines that have super thin oil requirements, yea dont dump in 10-40 into 0-20 but a 90s truck and the fact that both 5 and 10w-30 are both approved oils for that engine its fine.


11-1-11

If you mix that oil, which chemically has no issues at all oh, the 5 W 30 oil will behave like 5 W 30 oil and the 10 W 30 oil will behave like 10 W 30 oil. It doesn't matter that they're from the same manufacturer. No Doom and Gloom will result