noun
Refers to petroleum-based liquid fuels used for heating, power generation, or marine engines. Often used in technical, industrial, or regulatory contexts.
この工場では燃料油を使ってボイラーを動かしている。
This factory uses fuel oil to run its boilers.
船舶用の燃料油は重油とも呼ばれる。
Fuel oil for ships is also called heavy oil.
軽油 is diesel fuel or light oil, which is a lighter fraction than heavy fuel oil. 燃料油 can include both light and heavy oils.
ガソリン is gasoline/petrol, a light fuel for spark-ignition engines. 燃料油 typically refers to heavier liquid fuels and does not usually include gasoline.
Compound of 燃料 (nenryō, 'fuel') and 油 (yu, 'oil').