This sounds like a solution to a problem that does not exist.
Now, mixing windshield warsher fluid, that's batcrap crazy, right?
Now, mixing windshield warsher fluid, that's batcrap crazy, right?
Mixing Oil to top off?
- Thread starter TorchMini
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My Chevy 5.3 gets a 5 qt jug of Valvoline HM 10w30 in its 6 qt sump and 1 qt of NAPA 5w30 synthetic I bought on sale at every OCI. Simply because I refuse to buy 1 qt of the Valvoline at $6 a qt to finish filling the sump. I’ve done this for years and my truck just rolled over 226,000 miles and runs as good as it ever has with no oil consumption. Yes, I could buy 2 jugs of the HM 10w30 and have a partial jug sitting on the shelf for years but I just don’t.
What problem doesn’t exist?
Our GS350 F Sport (not aneconobox by any means) specs 0w20. Last time it got a jug of 5w20 and a quart of 0w20. The shame!
Engines damaged by adding a make up quart of different oil.
Not a problem if they’re the same brand - your econobox won’t know either way.
Didn’t say engines would be damaged.
I did say that oil performance could be degraded.
Ask Molakule. Ask HPL.
With just a slight tweak in chemistry, it sometimes happens that the oil foams up, or changes pour point, of viscosity, or fails any number of the required tests.
It’s degraded, in other words.
But you really have no way of knowing if that happens in your engine because you can’t see and can’t test the performance of the resulting mix.
You might be fine.
You might not.
In this case, the brands were both Mobil1, but the 5w20 was high mileage.
I had the 5w20 HM on the shelf for over a year.
But don't all oils basically have "ALL" the same stuff in them? You know, boron, zinc etc??? Now if one oil has moon dust in it, that might not work.
Agree that the chemistries are mixed and therefore changed. That does not necessarily mean degraded; it may be improved. Or it may be insignificant.
I personally have seen no problem, especially as compared to running an engine with severly low oil level.
As this happens every day, millions of times, I fail to see a problem.
Of course I could be wrong. It would be interesting to see data, repeatable data, showing specific problems.
I sometimes mix a qt of 5w30 into the 0w20 (Honda, 4.5 qt total, often Frankenbrew) at oil change. So far no problems after 100k+ miles.
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Not saying it's causing damage, however while I'd mix oils (and don't lose sleep over)
when I either have nothing different on hand or want to use leftover oil in my garage,
I wouldn't do this by intention and buy different oils to mix them from the beginning.
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Agreed, except possibly if you consider there seems to be no studies showing a problem using a different top off oil.
I have never seen an owners manual saying not to do so, but that does not mean one does not exist.
Imagination is not required. That's why licensing requirements and ASTM D6922 exist.
Astro, question for you. If there were a meaningful issue, don't you think there would be a warning printed on the oil container, or perhaps on an engine's oil fill?
Your thoughts?
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Do people analyze the food and drinks they put into their bodies to this same degree... Or do they just shovel all kinds of overly processed, sugary garbage down their gullet with reckless abandonment...
wemay
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We have no idea how often companies tweak their own formulas. I cant see how topping off with another brand of the same rated oil is even close to being a significant issue.
The issues related to refined sugar are well documented.
Mixing motor oil, not so much.
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