The Subaru Impreza is the most fuel-efficient sedan with an overall average of 6.4L per 100km. That’s not far off the mark of the averages in the list above — and we’re talking about a car with a 2.0iL LineartronicTM CVT transmission. It also comes standard with impressive interior and exterior features such as Apple CarPlay and Android Voice Recognition software, along with dual-zone automatic air-conditioning.