Light diesel oil (ldo) is a distillate fuel derived from the middle distillate fraction during crude oil refining. It is lighter than heavy fuel oil but heavier than standard diesel (hsd). Ldo is commonly used in industrial applications for low and medium-speed diesel engines and furnaces, where high-speed engine grade fuel is not essential. Key Features: Physical State: Liquid, typically light to dark amber in color. Viscosity: Lower than heavy fuel oil; does not require preheating in most applications. Calorific Value: Approximately 9, 500–10, 000 kcal/kg, providing efficient combustion. Sulfur Content: Typically higher than High-Speed Diesel (HSD); subject to regulation depending on region.