Marvel Mystery Oil has been around since shortly after Otto started selling 4 stroke industrial engines. Now that we are no longer allowed to use real gasoline, it is possible that that stuff might lubricate the lower part of the intake valve stems.
Now, compare today's oils with those of, maybe, 30 years ago. They have about as much in common as silent movies and Hi-Def TV. If there was an additive that would make your engine run for 25K miles between oil changes and half million miles between rebuilds, oil companies would be falling all over themselves to be first to be able to make such claims for their product. Priced at 4X the current oil, the consumer would break even and the oil companies would make the same revenue for 1/4 as much production, making motor oil as profitable as fuel.
