Specifications for several 3309 ATF fluids

[vtl]

https://www.bobistheoilguy.com/ester...ic-lubricants/

[AKAMick]

My take on reading that is esters are synthetic molecular formulations which the "lubricity" exceeds that of petroleum products, "In automotive applications, the first qualified synthetic crankcase motor oils were based entirely on ester formulations", Now I am even more unsure of which is better suited Mineral or synthetic ATF, does Lubegard increase "lubricity" by its use similar to ester based synthetics. maybe i just better leave this contradictory subject alone. "Esters are a broad and diverse family of synthetic lubricant basestock"

[vtl]

My take on reading that is esters are synthetic molecular formulations which the "lubricity" exceeds that of petroleum products, "In automotive applications, the first qualified synthetic crankcase motor oils were based entirely on ester formulations", Now I am even more unsure of which is better Mineral or synthetic ATF

Esters are unstable and can break back to acids and spirits.

Mineral base wears out and breaks under high temperature quickly and forms sludge. But otherwise is high polar, lubricate well, high dispersant, holds additives well.

Refined mineral base (hydrocracked, what in US is commonly called "synthetic") does not lubricate that well, does not hold additives well, forms sludge too.

PAO is not polar, can't hold additives, has the worst lubrication, but is highly thermostable.

Good engine oil usually have a mix of 60% PAO, 30% mineral and a few percent of esters.

But speaking about transmission: I never see ATF temp higher than 190-200 F in my AW55 equipped with external cooler. And mineral based 1161540/1161640 is a far superior ATF (while fresh) than anything else on the market. I spent north of $1000 experimenting with different ATFs in past years.

[AKAMick]

I spent north of $1000 experimenting with different ATFs in past years.

That's more than I'm willing to spend on ATF for my old Volvo XC's, thanks for your help.