Being possibly the #1 lubricant manufacturer in the world, why is Mobil 1 the only grease that reliably leaks on the shelves in stores? Couldn’t they do better? Am I wrong for assuming this is an issue?
and there are plenty of mixing calculators online. The short answer is that if you blend a two oils 50/50, you'll get something slightly LESS than the average of the two. You can verify this yourself on the calculators. Of course, these are just estimates.