two things Rondo, Not to be sounding rude, just wondering,
1- have you ever done an oil analysis on your mixed oils?, If so, would you share your formula of that mix, miles, engine, ect, and the #'s on that analysis so we might see just how good this mix is in comparision to what you'd get from the chemists mixing the oil. I think it would be interesting to compare your's against theirs.
2- If what you are wanting to do is increase an oils protection ability, then look at stp(thats right, you do use stp also don't you, forgot) or better yet Schaeffers 132 EP additive. These are designed to increase the viscosity of any oil by adding a heavier dose of EP additive and VI's, therefore more hydrodynamic properties, more clinging, and more barrier additive.