It can be used in most diesel engines, especially newer ones, and emits less air pollutants and greenhouse gases other than nitrogen oxides. Biodiesel is a renewable alternative fuel that can be used in a diesel engine either pure or in blends with petroleum diesel. According to the September 2005 issue, biodiesel prices for low-level blends (B-2 to B-5) are about the same as regular diesel, $2.81 per gallon biodiesel versus $2.81 regular diesel. On the other hand, biodiesel is created from animal fats and vegetable oils. It has the potential of replacing petroleum diesel in the future, or being used in blends with petroleum diesel to improve performance and reduce toxic exhaust emissions. Unlike petroleum diesel, which contains sulfur and carcinogenic benzene, two components the state emissions boards and EPA regulate, biodiesel is nontoxic and biodegradable. Biodiesel is likely to produce less power with high fuel consumption than diesel as the gross calorific value (energy content) of biodiesel is lower than petroleum diesel. The petroleum diesel is produced through a fractional distillation process of crude natural oil. Blends of biodiesel with petroleum fuel are widely used in the diesel engine [ 13 ]. It’s safer to handle and has virtually the same energy efficiency as petroleum diesel. The main differences are discussed below: The source: The primary difference between biodiesel and diesel lies on the source separating them. B-20 blends are about 10 cents more at $2.91. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics.