OK but how is that determined? I mean specs are for sure set as minimums, but it could be that mobil 424 meets the minimum and tsc exceeds it. We have know way of knowing so it's all just marketing at this point. I'm not making a case for either fluid, I'm just saying that proclaiming one oil is a better "j20c" oil because it's name brand is purely conjecture. All we know is both oils meet j20c and that is it, so on paper they are both equal. Without real lab data we are left to guess or form opinions based on loyalty and marketing.