Specifications include, but are not limited to: Gasoline: Each contractor agrees to provide standard unleaded gasoline with a minimum anti-knock index of 85.5, 87, 89 or 91, R+M/2, whichever product is ordered by the State. Minimum octane levels will be determined by availability, facility location/elevation and the specifications contained herein. Unleaded products shall comply with ASTM D4814-01 specifications. Products supplied under the resulting contract must be delivered in compliance with ordinances governing regulatory actions, such as oxygenated fuel, unless indicated otherwise by the agency. Diesel: Each contractor agrees to provide ultra low sulfur diesel fuel with a minimum 40 cetane index or maximum 35 volume percent aromatic; and sulfur content of 15 ppm maximum; and meeting ASTM D975-02 specifications. The State requires only Ultra Low Sulfur Dyed Diesel. If the vendor cannot deliver Ultra Low Sulfur Dyed Diesel because of availability issues the State will take Clear Ultra Low Sulphur Diesel. Biodiesel: Biodiesel fuel, when requested, is to be blended to B20 level prior to delivery. Blended biodiesel fuel shall be supplied by a vendor that is registered with the EPA to sell biodiesel and is licensed to sell diesel fuel in Montana. Biodiesel feedstock must meet or exceed ASTM D6751-02 specifications. Ethanol Products: All ethanol products delivered shall comply with ASTM D5798-98a, including seasonal blending adjustments. Montana law requires state agencies to use gasohol in motor vehicles, provided that the gasohol is priced the same or less as non-gasohol products. Vendors are encouraged to bid ethanol blended fuel, if available. All bids for gasoline products must be based on the vendor mark-up over the OPIS/rack price for regular unleaded fuel only. Contractors will be afforded the opportunity to supply gasohol provided it is available at the corresponding OPIS/rack price for regular unleaded fuel. Vendors shall indicate locations that are to be supplied with gasohol.