OVERKILL
$100 Site Donor 2021
There has been much discussion over the years and more recently, calculations that predicated on results from this Index, which was drafted up years ago by member A_Harman, to determine, roughly, the amount of VII in a lubricant. Essentially, the closer to 1 you got, the lower the VII content.
Given the recent extrapolations based on this, I thought it prudent to run the calculation on some base oils, which of course we know, have no VII in them. This proved somewhat difficult to do broadly because it would seem HTHS data for base oils isn't a parameter commonly published. Using what was available, I started with XOM Chemical's SpectraSyn line of PAO products and the results were what one would hope to expect:
SpectraSyn 8: 1.017
SpectraSyn 6: 1.077
SpectraSyn 4: 1.011
The only real stand-out being SpectraSyn 6, as it is closer to 1.1.
Then, I ran it on the SpectraSyn Plus bases, and this is where things got interesting:
SpectraSyn Plus 3.6: 0.874
SpectraSyn Plus 4.0: 0.886
SpectraSyn Plus 6.0: 0.936
So, if we were to use the A_Harman index as the basis for a VII content calculation on a lubricant with a significant component of it comprised of a SpectraSyn Plus PAO base, the perceived VII content would be artificially inflated.
Based on this, I would encourage those interested in this to see if they can find other bases that list HTHS, perhaps we can compile a list of base oil A_Harman indexes.
Given the recent extrapolations based on this, I thought it prudent to run the calculation on some base oils, which of course we know, have no VII in them. This proved somewhat difficult to do broadly because it would seem HTHS data for base oils isn't a parameter commonly published. Using what was available, I started with XOM Chemical's SpectraSyn line of PAO products and the results were what one would hope to expect:
SpectraSyn 8: 1.017
SpectraSyn 6: 1.077
SpectraSyn 4: 1.011
The only real stand-out being SpectraSyn 6, as it is closer to 1.1.
Then, I ran it on the SpectraSyn Plus bases, and this is where things got interesting:
SpectraSyn Plus 3.6: 0.874
SpectraSyn Plus 4.0: 0.886
SpectraSyn Plus 6.0: 0.936
So, if we were to use the A_Harman index as the basis for a VII content calculation on a lubricant with a significant component of it comprised of a SpectraSyn Plus PAO base, the perceived VII content would be artificially inflated.
Based on this, I would encourage those interested in this to see if they can find other bases that list HTHS, perhaps we can compile a list of base oil A_Harman indexes.