Vegetable oils and fats in comparison with diesel fuel have high viscosity, by transesterification method the viscosity of oil can be decreased. Transesterification of triglyceride with alcohol is one of the methods for production of biodiesel. In this study sunflower oil, methanol and ethanol, with molar ratio of (1:3, 1:4, 1:6, 1:8) and temperature (40, 50, 60 º C) were dependent parameters e...