Which fuel-oil is known to contain the most sediment?

No. 6 fuel oil is known to contain the most sediment among the options provided. This is primarily due to its higher viscosity and density, which lead to a greater level of impurities and particulates that can settle out in the fuel. The presence of these sediments can cause operational issues in combustion equipment, such as clogged filters and poor fuel atomization, affecting the efficiency and reliability of the burner system. No. 6 fuel oil is often used in industrial applications and in situations where cost-effectiveness trumps the need for cleanliness in the fuel. Understanding the sediment content in different fuel oils is crucial for oil burner operators to ensure proper maintenance and operation of equipment.