Characterization of the surface tension of vegetable oils to be used as fuel in diesel engines

► Existing diesel engines can be fueled with straight vegetable oils. ► Vegetable oils surface tension is higher than the one of diesel fuel. ► Surface tension has a deep impact on the combustion of existing diesel engines. ► Vegetable oils surface tension is reduced to match diesel fuel values by heating. ► Straight vegetable oils heating temperature should be about 120 °C.