Marvel Mystery Oil

Marvel Mystery Oil is one of the oldest surviving American petroleum additive brands, introduced in 1923 by Marvel Chemical Company and now produced by Marvel Oil Company, Inc. (Lombard, IL). The red-dyed, wintergreen-scented formula has remained largely unchanged in character for a century, though the current SDS (v2.1, revised 2025) discloses a more complex ingredient picture than the brand's heritage image suggests — including tricresyl phosphate (an organophosphate anti-wear agent), dichlorobenzene isomers, and petroleum distillates.

The brand markets the product as a dual-purpose additive for both gasoline and engine oil, claiming fuel system cleaning, valve lubrication, and engine protection benefits. These claims are manufacturer-asserted; independent tribology data for the specific formulation is not publicly available.