A few posts I found about MMO.


MMO was created in 1923, long before low sulphur diesel fuel was even a concept. Its purpose was to promote clean carburetors and fuel systems, which was a not-insignificant problem back then due to the inconsistent refining processes used. Conceived as an engine system cleaner (solvent) its purpose seems to have morphed more recently*into that of a fuel lubricity additive, which may explain its poor showing in the lubricity comparison quoted in a previous post if the solvent ingredients have remained unchanged. Promotional material about the product implies that it's "mysterious" formula is still the same.

So it seems a bit odd to me that one would want to use a chemical mixture that was designed to remove petroleum-based sludge and deposits as something to promote the the lubrication of components by petroleum-based fuel.

Here's what it is:
- About 75% aromatics (e.g., benzene)
- About 25% mineral spirits (i.e., mostly hexane)
- About half a percent of chlorinated hydrocarbons (yet another solvent)

So, the "mystery" is out. It's a solvent. Pure and simple.

The funny thing is, it's not an oil. In fact, it's just about the opposite of an oil. It's clearly nothing more or less than a solvent.

In fact, they should call it "Marvel Mystery Solvent" but I guess that wouldn't distinguish it from any other solvent, nor even from plain old gasoline for that matter.