Gallon. Treats up to: 640 Gallons. A concentrated, high-potency formula that keeps stored gas fresh for easy start-up next season and optimum performance year-round. Formulated to reduce the harmful impact of Ethanol-blended gasoline. Protects against gum and resin build-up. 1 oz. treats 5 gallons. For all 2 and 4-cycle gasoline engines.