Another thick/thin article to discuss

[Shannow]

Originally Posted By: fdcg27
Is there really such a thing as a true monograde?
Even absent VIIs, all basestocks have some inherent VI.
Therefore, is an SAE 30 really a monograde, or is it really something like a 25W-30?
Or are we defining monogrades as those oils which contain no VIIs and are therefore not subject to temporary shear?


Really ???

Monograde as per J300...containing no Viscosity Modifiers.

Of COURSE base oils have a viscosity index.

 

[Shannow]

Given that we refer to SAE J300 in every second thread...

 

[gfh77665]

Originally Posted By: Snagglefoot
Ok, how about this. If 0w20 bothers someone, use 5w30. I’m thinking after 15 years, there is no significant numbers of failures of Ford engines due to using 0w20 oil. If anyone has data counter to that, let’s see it.


Has there been "any significant numbers of failures of Ford engines due to using heavier oil like 5w-30 or 10w-30"?

If there is any data, then let’s see it.

 

[Y_K]

Thank you for the intelligent discussion.

Even though the article dates back to 2003, Physics involved did not change.

Still, some folks believe that their new and improved camel can go through the needle eye with aplomb

 

[ka9mnx]

Originally Posted By: Shannow
Originally Posted By: fdcg27
Okay, but you can easily find 10W-30s that have 3.5 HTHS and that was my point.
Many of those who think that they're looking for a thicker oil might really be looking for a higher HTHS oil.
As you are well aware, there are different ways of measuring viscosity and folks might be well advised to focus on those that actually matter in reducing wear.


That's why oils should be graded "xW-HTHS"...since the discovery of non Newtonian behaviour in polymer thickened oils in the 80s, HTHS has been the metric that counts.


Extremely well said by both of you. I totaly agree with the "xW-HTHS" idea. It's how I pick my engine oils.

 

[fdcg27]

Thank you, although your second reply would have been quite sufficient.