75w110 and call it a day
Mixing Differential fluids 75W-90 and 75W-110
- Thread starter urman
- Start date
Just use the 75W-110. Engines are not that sensitive to viscosity, let alone differentials.
Only the European ones though, right? The ones you told us have “unique bearing tolerances”.
Run the 75W-110
MolaKule
Staff member
Pray tell, where are getting your information so as to arrive at this conclusion?
like many conversations on BITOG, ever read any?Here, on this forum. Use the search button, you will find the same.
MolaKule
Staff member
I guess you'll have to explain sensitivity and unique bearing tolerances and what they signify.
Where did I use the words "sensitivity" and "bearing tolerances"?
MolaKule
Staff member
Post #22 https://bobistheoilguy.com/forums/t...75w-90-and-75w-110.393095/page-2#post-7180719
In tribological terms, what is engine sensitivity and unique bearing tolerances?
Engine sensitivity, in simple terms, refers to how an engine responds to changes in friction and lubrication between its moving parts. It's like how sensitive your skin might be to rough surfaces. Some engines are more "sensitive" than others to changes in oil quality, temperature, or wear patterns. This sensitivity determines how efficiently an engine runs, how it performs under different conditions, and ultimately how long it will last.
Post #22 https://bobistheoilguy.com/forums/t...75w-90-and-75w-110.393095/page-2#post-7180719
In tribological terms, what is engine sensitivity and unique bearing tolerances?
Bearing tolerances are essentially the allowable variations in the size and shape of engine bearings. These are the parts that allow smooth rotation between components. Imagine trying to slide a ring onto your finger - if it's too loose, it wobbles; if it's too tight, it won't fit or move properly. Similarly, bearings need to be manufactured within specific measurement ranges (tolerances) to function correctly. These tolerances are particularly important because even tiny variations can significantly affect how well an engine runs and how long it lasts. Different engine designs have unique tolerance requirements based on their specific operating conditions and performance needs.
Oh my. There is a lot of imagination going on in all of that.
Okay oil expert, what are your credentials? I'm a hobbyist that likes to read. You seem to know better, so, let's hear it. Make it easy to understand.
You're always asking for credentials. Do you mean my education? I've stated that before on here, but not very often. I don't think that is relevant but if it is, then I have a BSME and a minor in Chemistry. I'm not an "oil expert" nor have I ever claimed to be one. I'm only responding to things people post and that I'm reading.
But back to the post I called imagination. I said that because you're making up a bunch of stuff there. That whole paragraph on "engine sensitivity" is completely made up. Engines are not skin.
Bearing tolerances have nothing to do with this. Tolerances for bearings hasn't changed. Did you mean clearances? You tried to make this point earlier about how European engines require certain oils because of their "unique bearing tolerances". That's silly. They do not have unique bearing tolerances that result in needing a special oil. This is just pulled from thin air.
By the way, I'm not the only one questioning you about this. Ask the others for their credentials too please.
The problem with reading and watching stuff on the internet and YouTube is you get truths, half truth’s, urban legends and everything in between. It takes some critical thinking to see through most of it and not posting here unless you know what your talking about. We all get called out at times but try not to insult long time members that have made great contributions over the years. I suggest reading books by Dr. Leslie Rudnick.
MolaKule
Staff member
There is no such thing tribologically as engine sensitivity. A specific engine design may show, through testing, how it reacts to certain external factors. You're incorrectly using the word sensitive as if it had human attributes, a fallacy called "reification."
You have a basic misunderstanding of the difference between Tolerances and Clearances, so here is a link to assist in understanding the difference:
https://www.epi-eng.com/mechanical_engineering_basics/clearance_and_tolerance.htm
Now, we can use a mathematical tool called "sensitivity analysis" but this in the realm of sensitivity and specificity analysis such as in this study::
"Global sensitivity analysis of hydrodynamic lubrication performance for textured surfaces" from
https://www.sciencedirect.com/science/article/abs/pii/S0301679X22005588
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You do realize that I repplied to a question I was asked about something I don't know much about, so I read, put time into it, and provided an explanation using simple terms.
I see you still have beef with my "unique bearing tolerances". I know the difference between tolerances and clearances, and that's why two engines aren't the same when it comes to oil pressure. They are similar, but not identical. That's why manufacturers provide ranges for clearances. They try to make bearings wider, but not too wide, and a bit bigger, but not too big, to use thinner oils that the engine can move with as little energy as possible, and so that hydrodynamic friction is minimized. Some Euro vehicles call for 229.51 oil, for example, to protect emissions equipment and bearings (HTHS 3.5 or higher). Other Euro vehicles run fine on 0W-20, even Diesel engines, but they also have specific approvals. I doubt a Mercedes Diesel engine calling for 0W-20 will do well on API SP oil from Walmart. If these differences wouldn't matter, we wouldn't have different kinds of oils. But you're splitting hairs, coming after me, for trying to explain to someone why they should use Euro oil in a Euro car, using as few and simple terms as possible.
Engine metalurgy matters to oil formulation. That is why sometimes we have specific oils for specific engines. One of the many reasons I should say.
Thank you for the link, I'll read it.
Again, I am not an expert, nor do I claim to be.
I think it would be useful to have tags or badges showing who's an expert and who's a hobbyist, novice, etc. Heck, I wouldn't mind being tagged as a novice or hobbyist, because that's essentially what I am.
MolaKule
Staff member
I don't think that is a good idea since one would have to go through a list of all members to make that determination, and by what criteria?
We are all hobbyists in the sense that our interest is the "hobby" of automobiles, their drivetrains, and lubricants.