Operating costs for fleet managers are fixed and variable. Extending the life of an engine, adding lubricity to meet oncoming ultra low sulfur, and running cleaner engines results in lower operating costs. Biodiesel also makes a tremendous parts cleaner. The product is easier on your hands and does not leave the typical odor of a solvent. This product demonstrates its own quality. All of the reduction in carbon emissions, reduction in oil imports, and increased local economic activity come at no extra charge. Biodiesel offers fleet operators a safer, cleaner alternative to petroleum diesel. Biodiesel is also a cost effective tool when complying with federal regulations. The Energy Conservation Reauthorization Act of 1998 allows federal, state and alternative fuel provider fleets who must comply with the Energy Policy Act (EPAct) and Executive Order 13149 to meet up to 50 percent of their light duty alternative fueled vehicle purchase requirements with biodiesel. The biodiesel fuel use credit gives fleets and covered persons, who are otherwise required under EPAct to purchase alternative fuel vehicles (AFVs), the option of purchasing and using 450 gallons of biodiesel in vehicles in excess of 8, 500 lbs. gross vehicle weight instead of purchasing an AFV. Biodiesel operates in conventional engines. Biodiesel blends operate in diesel engines, from light to heavy-duty, just like petroleum diesel. B20 works in any diesel engine with few or no modifications to the engine or the fuel system, and provides similar horsepower, torque, and mileage as diesel. Pure biodiesel is not compatible with natural rubber, sometimes found in pre-1994 vehicles. Because it is a solvent, it can degrade natural rubber hoses and gaskets, so those would need to be changed to more modern material if B100 is desired. This is not a problem with B20 blends (20 percent biodiesel/80 percent diesel) and below. Biodiesel does not require special storage. In fact, in its pure form or in blends, biodiesel can be stored wherever petroleum diesel is stored, except in concrete-lined tanks. Acceptable storage tank materials include aluminum, steel, fluorinated polyethylene, fluorinated polypropylene and Teflon. The fuel should be stored in a clean, dry, dark environment. At higher blend levels, biodiesel may deteriorate natural rubber or polyurethane foam materials. Biodiesel also has a higher flash point, handles like diesel and is safe to transport. Users should be sure to verify compatibility with materials exposed to neat biodiesel.