Is PAO (Group IV) no longer important?

[OVERKILL]

Unless I'm mistaken, I think he's basing his comments on the KRL test results.

Some info for those learning like me:

CEC L45-A-99 - The KRL Tapered Roller Bearing test is becoming the test of choice of many OEM’s around the world, as it is considered the most severe and offers the best correlation to actual field performance. Test oil is run in a fitted tapered roller bearing for 20 hours under design load. Before and after viscosities are compared for percent viscosity loss.

The graph below shows a 12.6% reduction in viscosity shear loss from a shear unstable oil to a shear stable oil as tested in the KRL Tapered Roller Bearing test.

View attachment 192212

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The dual clutch ATF is made from GTL (87.7%), mPAO (1.5%), PPD (0.3%) and when tested:


His second example was the 75W90. GTL (56.02%), mPAO (38.68%), PPD (0.4%) and when tested:

That's all relative to VII performance, we are talking about PPD's.

 

[oil pan 4]

You're using 5w20 in a Heavily modified 1984 6.5L suburban (to this day)?
If that's your ride, then your wife's vehicle never got listed in your signature.

I never put 5w-20 in any diesel. That's my wife's car. I change the oil in the suburban about once every 2 or 3 years, it gets 5w-40.