Advantage of a higher VI ???

[Oregoonian]

I'm planning on my next OCI....going to a 0w20. Of course all the 0w20's availlable are synthetic....but they vary in their VI from the 160 and 170's to over 200.

Are there any advantages to using a high VI oil?....and if there are....what are they? Could those who are knowledgeable in this area be specific..... and list good reasons why going to a high VI oil would be benificial.

Appreciate your input and opinions.

 

[CATERHAM]

This has been discussed a lot before, but basically a high VI oil is lighter on start-up and during the warming up period.
It's not overly important if your engine spends 99% of it's operating time already up to temperature, but for most applications a significant amount of an engine's life is spent with the engine oil below normal operating temperature.
With ultra high VI oils that means starting your car with an oil the equivalent of one to two grades lighter (up to 60%) every time you start your car. The benefits are numerous, including less fuel consumption, reduced engine wear, more power and greater engine responsiveness when during the warming uop period.

The Sustina 0W-20 has a 229 VI. Their video explaining the benefits is quite interesting (the good part doesn't start till 1/3rd of the way through:
http://www.sustina.us/product-line.php

 

[Rand]

I love that oil problem is the cheapest I've found it is 79$ for 6qt and I need 6 qt/change :\

I'll take a regular 0w20 or the g-oil 5w30 that shears to a 20wt in a couple thousand miles(in some applications)

 

[The Critic]

The problem with VII traditionally is that they leave deposits behind in engines, and are prone to shearing. A high-quality, shear stable oil is not likely to contain a significant amount of VII. However, I am guessing that it is possible for certain VIIs to perform better than others?

 

[mechtech2]

Originally Posted By: CATERHAM
This has been discussed a lot before, but basically a high VI oil is lighter on start-up and during the warming up period.
It's not overly important if your engine spends 99% of it's operating time already up to temperature, but for most applications a significant amount of an engine's life is spent with the engine oil below normal operating temperature.
With ultra high VI oils that means starting your car with an oil the equivalent of one to two grades lighter (up to 60%) every time you start your car. The benefits are numerous, including less fuel consumption, reduced engine wear, more power and greater engine responsiveness when during the warming uop period.

The Sustina 0W-20 has a 229 VI. Their video explaining the benefits is quite interesting (the good part doesn't start till 1/3rd of the way through:
http://www.sustina.us/product-line.php


A high VI makes your oil act 2 grades thinner?
Nonsense.
Read the viscosity on the label for that function.

 

[CATERHAM]

Originally Posted By: mechtech2
Originally Posted By: CATERHAM
This has been discussed a lot before, but basically a high VI oil is lighter on start-up and during the warming up period.
It's not overly important if your engine spends 99% of it's operating time already up to temperature, but for most applications a significant amount of an engine's life is spent with the engine oil below normal operating temperature.
With ultra high VI oils that means starting your car with an oil the equivalent of one to two grades lighter (up to 60%) every time you start your car. The benefits are numerous, including less fuel consumption, reduced engine wear, more power and greater engine responsiveness when during the warming uop period.

The Sustina 0W-20 has a 229 VI. Their video explaining the benefits is quite interesting (the good part doesn't start till 1/3rd of the way through:
http://www.sustina.us/product-line.php


A high VI makes your oil act 2 grades thinner?
Nonsense.
Read the viscosity on the label for that function.

And how does reading the "viscosity on the label for that function" tell you an ultra high VI oil 0W-20 oil will be 60% lighter than a low VI 5W-20 on start-up? It doesn't.

 

[GMorg]

I've never seen a "viscosity on the label" that can tell me anything about the viscosity at start-up. Where can I find that information? The winter grade refers to a reference temperature that has nothing to do with my start-up temperatures. 0W-20 and 0W-40 do NOT have similar startup viscosity at most temperatures.

 

[CATERHAM]

GMorg, exactly.
That's a major problem with the antiquated SAE grading system.
If it was a requirement to show some actual PDS spec's on the back of the bottle including HTHSV and VI that would help a lot.
But our good friend Tom_NJ says that will never happen.
As it stands the SAE grade on a bottle of oil is more about marketing than anything else.

 

[CATERHAM]

Here's another video explaining the advantages of a high VI oil in racing applications. Click on viscosity index 101 at the bottom of the first page:
http://www.joegibbsdriven.com/

 

[mechtech2]

Originally Posted By: GMorg
I've never seen a "viscosity on the label" that can tell me anything about the viscosity at start-up. Where can I find that information? The winter grade refers to a reference temperature that has nothing to do with my start-up temperatures. 0W-20 and 0W-40 do NOT have similar startup viscosity at most temperatures.


But it is so easy to imagine a graph line of temp/viscosity.
It would be close enough for all but a scientific paper.
There is not that much to know.