"Gasóleo" refers to diesel fuel, which is commonly used in vehicles with diesel engines. It is a type of fuel that is derived from crude oil and is less refined than gasoline. In Spanish, "gasóleo" is used to describe the fuel itself or the diesel type of fuel generally. It is more frequently used in oral speech than in written contexts.
Examples
Spanish: Mi coche funciona con gasóleo.
English: My car runs on diesel.
Spanish: El gasóleo es más caro que la gasolina actualmente.
English: Diesel is more expensive than gasoline currently.
Idiomatic Expressions
Echar gasóleo al fuego: To worsen a situation.
Example:Spanish: No vamos a echar gasóleo al fuego, simplemente trataremos el asunto con calma.
English: We're not going to worsen things, we will just handle the issue calmly.
Ir como el gasóleo: To do something smoothly.
Example:Spanish: Maria siempre saca buenas notas, todo le sale como el gasóleo.
English: Maria always gets good grades, everything goes smoothly for her.
Etymology
The word "gasóleo" comes from the French word “gasoil”, which is a blend of "gaz" (gas) and “huile” (oil).