Octane Disclosure Act - Requires disclosure to prospective purchasers of gasoline sold or shipped in interstate commerce of specified information which relates to the octane rating of such gasoline. Requires the Administrator of the Environmental Protection Agency to inspect retail establishments to the extent necessary to enforce such disclosure requirements. Sets civil penalties for the violation of such disclosure requirements.

Amends the Federal Trade Commission Act by making it unlawful for automobile manufacturers to fail to provide written information relating to the octane levels of gasoline appropriate for use in the engines of each automobile sold or shipped in interstate commerce.

Authorizes the Federal Trade Commission to develop standard methods for calculating octane ratings and for testing and assuring the purity and content of gasoline.

Amends the Federal Trade Commission Act by requiring the Commission to publish information correlating octane ratings of gasoline sold to purchasers with octane ratings contained in literature furnished by automobile manufacturers.