I'd agree with low-temperature viscosity being possibly messed up with mixing. Also, mixing creates different percentages of AW, FM, detergents, etc., all the additives are now a special one-off mixture, which blenders try to optimize to pass dexos1, SN, LL-01, etc., the performance tests.
I'm sticking with the understanding that mixing using Infineum additives (Pennz-Mobil-Quaker-Shell) doesn't create major issues, though using across other brands carries a higher risk of problems.
I'm sticking with the understanding that mixing using Infineum additives (Pennz-Mobil-Quaker-Shell) doesn't create major issues, though using across other brands carries a higher risk of problems.