Diesel Fuel Supplement, 26oz, +Cetane Boost. A winterizer/antigel that is used in the cold winter months to prevent fuel gelling and kep fuel-filters from plugging with ice and wax. When temps drop, this will help provide trouble-free winter operation for diesel fuel. Contains anti-icing additives which protect against fuel-filter icing. Effective in all diesel fuels, including ultra low sulfur diesel (ULSD) and biodiesel blends containing up to 20% biodiesel (B20).