This is copied from another thread.

We analyzed and tested both of these additives at Exxon.

Marvel Mystery oil is 30% varsol (charcoal lighter fluid) and 70% 30wt base oil some red dye and wintergreen fragrance. It is from the late 1920s.

Avblend is very light weight paraffinic base oil (sewing machine oil)with 1% ether and blue dye. It is from the late 1950s. If it is absorbed by the metal, why doesn't it leak out of the can?

These are solvent type products. Some people find them beneficial for sticky valves or some sludge dispersal. If you are depending on them for either of these reasons, you have bigger problems.

Both evaporate within hours in an engine. Neither one provides any corrosion protection or anti-wear benefit. Neither one will harm anything in the recommended concentration.

Regards,

Ed

Edward Kollin
Techncal Director
Aircraft Specialties Lubricants
www.aslcamguard.com