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2017 Foz 2.5i CVT
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Discussion Starter · #1 ·
Someone posted this link on the Ford-Trucks.com page and I found it interesting, not that I know the full significance of every number. It is only for major brand non-synthetic 5W30's, but since that's a common Subaru weight, I find it relevant:

Petroleum Quality Intitute of America

Apologies if it's been posted already,
George
 

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2016 & 2018 2.5i Premium CVT
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Interesting. Most of the numbers are all in the same ballpark so, whatever they mean, they don't seem to mean much in terms of comparison between brands. But some of the additive figures are startlingly different. Magnesium, molybdenum, boron, sodium each are quite consistent among the majority of brands but significantly different in a few.

Look at Castrol's figure for sodium: 357, with all but Valvoline showing <1. I wonder if my blood pressure would go down it I switched to another brand.
 

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2017 Foz 2.5i CVT
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Discussion Starter · #6 ·
Moly content is different...

Among the few things I know is that moly (as in molybdenum disulfide) is something you want for a flat tappet engine as well as ZDDP, which will show as zinc. I've got a '91 BMW 318is with a flat tappet cam and have been using Havoline or Castrol 10W40 in it. Looks like the Havoline is more of what I want in that car. I've also run it on Shell Rotella 15W40 for many years and the Shell 5W30 looks good for moly--the Rotella hopefully has even more moly and zinc because it's a truck oil. I do know that Zinc content in car oils has gone down in recent years because it's not so good for catalytic converters (if you are burning some oil). Not as much of a problem with roller cams.

Also, the TBN is the total additive content (and when this gets low, the oil is worn out). I'm surprised to see Valvoline as the lowest TBN number in the bunch, and this makes me feel a bit less good because that is what the Honda dealer uses as their standard oil for my wife's '07 Civic--which has a monitor system that has let us run the oil out to 9k miles or so. Looks like I'd rather have Mobil 5000, Pennzoil YB, or Castrol in there. I've probably used more Valvoline in my life than anything else, but used to do 3-4k changes, so the TBN probably wasn't as critical there.

I'm guessing that different oil weights (such as the 5W20 that goes in the Honda or the 10W40 in my BMW) are going to have similar additive packages, but that is only an assumption.

I'd like to see a comparo on different weights, on synthetics, etc, so I will try to keep an eye on this website and see what they come up with.

George
 
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