Ask The Editors: Unraveling the Mystery in Marvel Mystery Oil
Marvel Mystery Oil has been around since the mid 1920s and has been marketed and sold as both a fuel and oil additive designed to increase engine performance (by creating a tighter piston ring seal and thus higher compression) as well as clean out deposits left by the chemicals found in pump gas. Does it live up to its claims? That answer is much harder to tell.
We can take a look at precisely what you’re buying when you pick up a bottle of the stuff- 74% of the fluid in the bottle is actually standard fair mineral oil. 25% is the solvent known as mineral turpentine and the 1% left over? That would be pig fat or as it is more commonly called, lard. This is the ingredient often credited with the formula’s unique and appetizing aroma.
It’s benefits make more sense when used as an oil additive than they do a fuel additive and the reason for this is very simple: Since the Mystery Oil contains no octane increasing capabilities, adding it to gasoline (regardless of its potential benefits at removing deposits/ cleaning fuel system internals) dilutes the octane rating of your fuel.
We talk about this often and it is crucial to reiterate it again here- octane is not a measure of a fuel’s performance capabilities but rather a measurement to inform the buyer of the gasoline’s resistance to detonation (or knock). The higher performance (compression) engine you run, the higher the octane rating required to prevent detonation from taking place.
We’d personally steer clear of the stuff in the sensitive arena that is your ATV’s fuel system. There are a wide variety of fuel detergents and cleansers on the market that come with the added bonuses of stabilizing fuel and maintaining a consistent octane rating these days.
As an oil additive, a little bit in the crankcase is much more practical, especially in older ATVs that seem low on compression. As a bonus, your exhaust will ever so slightly contain the aroma of bacon.
