Tank location and storage temperatures affect a fuel’s storage life. As diesel fuel is stored, it slowly reacts with oxygen in the air to form gums and varnishes. As temperatures increase, the reaction also increases. The addition of contaminates such as water or rust accelerates this process. Generally, fuel should not be stored longer than six months. If long-term storage is required, the tank should be located underground or inside to reduce temperature extremes, and it must have proper ventilation caps. If storage exceeds one year, testing is recommended. The storage stabilizer additives in Cenex Roadmaster XL® and Cenex® Ruby Fieldmaster® reduce the formation of gum and varnish and can extend the fuel’s storage life.