Mystery Oil?
 

Does anyone use Mystery Oil in their diesel fuel or in the crankcase? What is your opinion on synthetic lubricants? These were recommended by an independent mechanic. If you have used these items, what are the results?

No, I don't use mystery oil. And yes I use synthetic when driving on raceways and in winter if temperatures drop to 10 F or below.

Stuff like Bardahl, Rislone and Marvel Mystery Oil claim they can make your engine run quieter and smoother, and reduce oil burning. These are products which contain solvents or detergents such as kerosene, naphthalene, xylene, acetone or isopropanol. If used properly, I suppose these products will strip off your Teflon and zinc protective coatings. But unless you have a really old and abused car, you probably have no need of stripping away sludge and deposits from your engine. Thus, you probably have no need for these wonder cleaners. If you overuse such products you can damage your engine by promoting metal to metal contact.

Marvel Mystery Oil, Bardahl, etc. are products that had a certain amount of effectiveness in certain conditions thirty years ago.

One of the most highy improved automotive related products today is your engine oil. The additive packages in modern motor oil are the TRUE "marvel."

That said, I keep a can of Marvel Mystery Oil in my shop all the time. I use it to lubricate my air tools. I make real sure that it doesn't get any closer than that to my cars.

My recommendation is to use the correct engine oil from your favorite producer. As far as the additives, the old spaghetti sauce commercial said it best; "it's in there."

Good luck,

I've never put the two into clear containers to compare them, but I can't help but notice that Marvel Mystery Oil looks very similiar to ATF.

Most people whose sailboats have Atomic 4 gas flathead engines use Marvel Mystery Oil in their gas in order the keep their valves better lubricated. The valves have a tendency to stick on these engines and the oil is reputed to help, even by the most experienced rebuilders of the engines. I see no reason to put it in my cars.