Diesel engines are used in a wide range of industry such as agriculture, transportation, building and energy production due to their high efficiency. Besides, with the development in electronics technology diesel engines are being more and more used in automobiles. Because a good many of diesel engines are being used, we are in need of petroleum more than ever. On the other hand, it is also commonly recognized today that the world petroleum energy resources are finite, thus many researchers have been carried out to find suitable alternative fuels to petroleum products. Researches, on alternative fuels to petroleum based fuels, are increased since petroleum fuels are finite, as well as pollution resulted from their combustion have sincere affects on environments. It is important for an alternative diesel fuels to be technically acceptable, economically competitive, environmentally acceptable and easily available. Many researchers have concluded that biodiesel holds promise as an alternative fuel for diesel engines. Therefore, biodiesel can be used in diesel engines with few or no modifications. Diesel-fuel blends with biodiesel have superior lubricity, which reduces wear and tear