This is the 18363rd most frequent Russian word.
экономичные
"Economical" – cost-effective or resource-saving.
Describes objects (lamps) being efficient and cost-effective in energy consumption.
Эти лампы очень экономичные, они потребляют мало электроэнергии.
These lamps are very economical, they consume little electricity.
Compares different objects (car models) regarding their cost-efficiency in operation.
Новые модели автомобилей более экономичные, чем предыдущие.
The new car models are more economical than the previous ones.
Referring to systems being designed to save resources or reduce costs effectively.