Fuel oil or heavy oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid fuel that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash point of approximately 40 °C (104 °F) and oils burned in cotton or wool-wick burners. In this sense, diesel is a type of fuel oil. Fuel oil is made of long hydrocarbon chains, particularly alkanes, cycloalkanes and aromatics. The term fuel oil is also used in a stricter sense to refer only to the heaviest commercial fuel that can be obtained from crude oil, i.e., heavier than gasoline and naphtha.
|Density at 15 °C||kg/m3||-||890||900||920|
|Viscosity at 40 °C||mm²/s||5.5||6||11||14|
|Aluminium + Silicon2||mg/kg||-||-||-||25|
|Pour point, Summer||°C||-||0||6||6|
|Pour point, Winter||°C||-||-6||0||0|
|Calculated Cetane Index||45||40||35||-|
|Parameter||Unit||RMA 30||RMB 30||RMD 80||RME 180||RMF 180||RMG 380||RMH 380||RMK 380||RMH 700||RMK 700|
|Density at 15 °C||kg/m3||960||975||980||991||991||991||991||1010||991||1010|
|Viscosity at 50 °C||mm²/s||30||30||80||180||180||380||380||380||700||700|
|Aluminium + Silicon2||mg/kg||80||80||80||80||80||80||80||80||80||80|
|Pour point, Summer||°C||6||24||30||30||30||30||30||30||30||30|
|Pour point, Winter||°C||0||24||30||30||30||30||30||30||30||30|
Maximum sulfur content in the open ocean is 3.5% since January 2012. Maximum sulfur content in designated areas is 0.1% since 1 January 2015. Before then it was 1.00%.
The aluminium+silicon value is used to check for remains of the catalyst after catalytic cracking. Most catalysts contains aluminium or silicon and remains of catalyst can cause damage to the engine. The flash point of all fuels used in the engine room should be at least 60 °C. (DMX is used for things like emergency generators and not normally used in the engine room. Gaseous fuels such as LPG/LNG have special class rules applied to the fuel systems.)