Como dizer "Gastar (consumir) em inglês

Sugestões:

• A: Porque vendeu o aquecedor? [Why did you sell the heater?]
• B: Porque gastava muita energia. [Because it uses too much electricity. Because it used too much electricity. Because it guzzled electricity. Because it guzzles electricity.]

• A: Porque vendeu o carro? [Why did you sell the car?]
• B: Gastava muita gasolina. [It guzzles gas. / It guzzled gas. It used too much gas. It uses too much gas.]

Bons estudos.

Porque qualquer "heater" consome muito combustível (ou energia) e nem todos os carros são beberrões.

Porque você coloca a primeira frase no presente e a segunda no passado se elas tem a mesma ideia?

Also

- Why did you sell the heater?
- Because it burns a lot of fuel.

- Why did you sell the car?
- Because it drank a lot of petrol (or diesel).

Sugestãozinha (com algo mais):

"Sold it because the (darned) thing guzzled a lot of gas (and also consumed an amazing amount of oil)."

Because it (the AC) was an energy guzzler.
Because it (the car) was an energy guzzler.

Also "energy hog" to both, provided that your car is eletric one", other than that you could say that it´s a gas guzzler.
Of course if you have problems with your car, even if it is gas-powered, then something a radio for instance, could be an energy hog in your car. It would be the cause of the quick depleting of your battery.