Marvel Mystery Oil - Your Opinion?

[Guest California_Reatta]

I recall many years ago my Uncle was a HUGE fan of adding Marvel Mystery Oil to the gas tank. I had no problem doing that to my 75 Dodge Dart Swinger, but I am much more hesitant to do it to a car I love (89).

Anyone have any thoughts on using this product? If yes, how often and what are the expected benefits?

Thanks in advance.

[Guest F14CRAZY]

No, it's not a mystery...main ingredient of this stuff is mineral spirits. What it would be doing is similar to injector cleaner and would clean any crud out of the injectors and lines. Wouldn't hurt it at all to use it once in a while

[juddev]

I use it to oil my air tools.

[Guest imported_barra]

The Marvel oil is one of many that are on the market. A mechanic once told me that nothing chemical was going to cure anything mechanical. I believe that the oil is safe. I know people who use it in their airplanes. I'm not sure if there is an STC that covers that but,so far, no engine failures have been reported.

Marvel seems to have a light-weight viscosity by comparison to an STP type and therefore should not increase the oil pressure in your engine which could put increased stress on the seals. I added a Lucas product to my oil and noticed a pressure increase on the gage.

[Guest F14CRAZY]

juddev: in this case it's being added to the gas, not crankcase oil.

I might actually use it in the oil in some cases, with some engines, like 50 miles before an oil change. Done it with Sea Foam before and Mystery Oil would act about the same. In this case it's a good engine detergent, but not normally needed