You posted stuff you nor anyone here understands, so explain it. Don't try and turn it around on me.
How do you know what I do or do not understand? Are you really saying that
no one else here understands the science behind motor oils? It's chemistry but it isn't overly complex. The problem is spending the time drilling down to get the relevant data so an apples-to-apples comparison can be made.
Your posting up of some mathematical formula and then asking me to decipher it was offbase and argumentative. However, I will state, for ease of understanding and as a frame of reference, that:
Water at 20 °C has a kinematic viscosity of about 1cS.
Does that help?
You also stated wear comes from thick oil. Totally wrong, wear comes from metal to metal contact for the most part.
Uh, no I didn't. Reread what I said. It is well known that a significant portion of engine wear comes from startup when the oil is not at operating temperature nor optimal viscosity (10cS) as engineered by the overall oil volume, oil gallery diameters, pump volumetrics, etc. You are correct in that wear is metal-to-metal contact. Our (apparent) argument is what is causal to that wear.
The thicker the oil the better the protection.
Completely and blatantly false.
What thicker oil does require is more pressure to push it and more energy to push it, so I am in know way telling anyone to run heavy oils like 50 weights. I've managed to get by on about 6 cars
and nearly a million miles in my life. And only 2 of those were bought new. The rest were all 10 year old or better when I bought them. Never lost a motor, never wore out a motor or even burn't a valve in anything
but race cars.
I agree with your assertions about thicker oil. I would add that clogged oil galleries, occluded filters, sludge buildup, and dirty oil all also increase pressures.
Your annecdotal evidence that you "never lost a motor" doesn't support any of your previous arguments. You can't prove a negative.
And I didn't have to answer why I run 30w in the summer. It's obvious, because it is 30w, 10-30 is not.
The only thing obvious is your misunderstanding of modern motor oil grade chemistry and your (and many others') confusion about the naming/numbering conventions on motor and gear oil containers.
A straight 30 grade is as much a 30 grade oil as a 10W-30 at operating temperature. The difference is the source (base stocks, i.e. how they get there) and additive package formulation.
Here is a great piece on the differences of mineral vs synthetic oils, and compares the same weigh or grade of oils showing that the operating viscosities are the same whereas the startup viscosities vary.
I am not a fanatic about when I change it, if it's spring it gets 30 wt. If it's summer or fall it gets 10-30. When it's cold (below 0 f.) we plug in.
That's my point my friend.
Engines are designed and optimized to run at operating temperature, which for motor oils, approaches 190-212F, and which correlates to 10cS on the viscosity scale. If your motor oil never cooled off, the outside temperature would be irrelevant when it comes to motor oil choice; a 30 grade oil would sustain 30 grade characteristics -- and lubricity -- whether you were in the middle of winter in Alaska or in Death Valley in summer. The issue is what happens when your motor oil cools down to 75 F ambient and you go out and turn the key. A straight 30 grade has a lot further to go (250cS--->10cS) to get to op temp than a 0W-30 (40cS--->10cS) and that correlates to wear, plain and simple.
Thin oils are for the epa mileage game.
If you are referring to multi-grade oils like a 0W-30, then that's your opinion, and I can respect that. However, I disagree that the intent of the automakers and engine designers in recommending a lower viscosity oil is simply related to fuel economics. Engines are designed and manufactured with far closer tolerances than ever before and that requires oils that can pass through these channels to keep these engines sufficiently cooled and lubricated. I think you'd agree with the assertion that a faster-flowing motor oil correlates to a cooler engine. :tu:
And I would love to see how 75 w is 30 w at 212. Since the oils viscosity is rated at 212 for oils. Do you have a link?
I didn't say a "...75 w is a 30 w at 212". I said that a 75W-90 gear oil shares the same viscosity of a 10W-40 motor oil at operating temperatures. This data is readily available in many places. This page on
BITOG is just one. However, the link YOU posted above in support of your argument also has the info. Did you read it?
Here it is directly from your source. It is the first 'chart' on the page.
:tu::tu: