这款车的燃油经济性很出色，每百公里只需6升油。

This car has excellent ___fuel-efficiency, using only 6 liters per 100 kilometers.

这款新车的燃油效率很高，每加仑汽油可以行驶50英里。

This new car has excellent ___fuel-efficiency, getting 50 miles per gallon.

这款新车采用轻量化设计，显著提高了燃油效率。

This new car uses lightweight design to significantly improve ___fuel-efficiency.