Originally Posted by Triple_Se7en
On the week of November 1st, when I do my winter OCI, I will be mixing four quarts of Castrol Edge Black 0W40 with two quarts of Mobil-1 AFE 0W20 for a 6K run to April 2020.
Been doing this blending stuff for almost 30 years. 1st and last owner of my vehicles and when I drive the badly rusted vehicle to the junkyard 18 years later, there is no engine ticking - no blue smoke at startup and the engine runs / sounds perfect..... about 250/275k later.
So your theory that this viscosity blending stuff is somewhat bad....well..... you are dead wrong about that. I am living proof. I want to be near a 0w33 with this blend and I should be knocking on that door. This summer I will run straight 0W40 in that Colorado 3.5. But not in Michigan's cold winter. This five cylinder engine has been treated delicato by me.
Obviously, it has worked for you, but the experience really only
proves these things:
1. You have not reached the ultimate limit of your blends, whatever or wherever that may lie. That's good for you, but nobody (including you) knows when, where or how your mixtures will fail (ALL oils WILL fail -- it's only a question of when). No way to tell with this "protocol."
2. A misunderstanding of the SAE grading system. There's no such thing as an "0w-33" oil. The SAE numbers, of course, represent
ranges of viscosities. You can attempt to calculate the
viscosity in centiStokes of specific mixture, or you could send a sample to a lab for an actual reading. Then you can say, "the resulting mix tests (or calculates) as x cSt, and therefore would fall within the 30 wt range.
3. You enjoy mixing oils, presumably hoping to derive some benefit from doing so. That's perfectly OK, it's your equipment and money and I really hope it continues to work out for you. Seriously. But I won't be doing it.
Enjoy.