Anyone explain this thinking please? Some saying "no to VIIs" when others recommend VIIs.

[SammyChevelleTypeS3]

And Nissan found more timing chain wear in oils that include VM.

Very interesting. One would not think just something like a VM would make such a difference.

 

[chris719]

'Not going to look them up but there are studies comparing an oil with and without VM that show less wear in oils that include VM in the formulation.

ali

C

Post in thread 'Use 10W-20 as a replacement for XW-20 and XW-30 applications?'

Nov 20, 2023

It’s no shocker that some VII would give slightly better cold properties over a similar oil with no VII, but it would be a surprise if there were wear, deposit, or other benefits. Any chance you can dig them up?

https://spiral.imperial.ac.uk/bitstream/10044/1/45361/1/Marx-N-2017-PhD-Thesis.pdf

Page 73 has a good summary of the findings of various groups.

Okrent [54,55] found in engine tests that polymer-containing oils decreased friction
compared to Newtonian mineral oils of the same viscosity at a given temperature (an
equivalent Newtonian mineral oil) [54]. To his...

• chris719

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[ChrisD46]

If you have a GDI engine then consider using off the shelf Mobil and Pennzoil oils containing better base stocks which would require less VII’s or they use better quality VII’s in oils such as 5W30 or 0W20. Valvoline and Castrol may very well be using high quality VII’s as well (not sure) .