Specifications include, but are not limited to:. Delivery of Biodiesel Fuel for the City of Cambridge and City of Newton. The City is seeking a vendor to furnish and deliver B5 and B20 biodiesel whose biofuel portion is made from waste grease, oils and fats as specified below. While the City expects to use B20 almost exclusively, it may order B5 at one or more locations during winter months or other times at its discretion 1. B20 biodiesel is a blend of 20% B100 biodiesel and 80% Ultra Low Sulfur Diesel; B5 biodiesel is a blend of 5% B100 biodiesel and 95% Ultra Low Sulfur Diesel. The biodiesel component must be produced from 100% waste grease, oils and fats that meet the latest ASTMD6751 prior to blending with Ultra Low Sulfur Diesel.