If only is was as simple as this guy lists things.
Sulfated ash is the result of treating some oil with sulfuric acid, incinerating, and other lab treatments of the sample. The constituent components of the ash are more important than the quantity. The main component of the sulfated ash comes from detergents, and those are usually magnesium or calcium compounds. The magnesium ash is abrasive while calcium ash is oil soluble and soft. But, they read-out the same in the lab test.
The zinc content numbers are so close as to be meaningless, and likely within the lab test tolerances.
TBN level of new oil is not a huge clue about much of anything. The TBN level remaining in used oil is a very important factor. A high initial TBN does not necessarily relate to a long-lived TBN.
The viscosity index is calculated on the viscosity changes between 40°C and 100°C, and does not necessarily relate to the viscosity of very cold oil.
In any case, the results of used oil analyses are more significant to picking a good oil than looking at new oil specs.
Ken
