What should you consider when planning a fuel-efficient route?

When planning a fuel-efficient route, avoiding heavy commuter traffic is crucial as it can significantly impact fuel consumption. Stop-and-go driving and idling in traffic can lead to increased fuel usage due to frequent acceleration and deceleration, as well as prolonged periods without optimal engine performance. By selecting routes that are less congested, you can maintain a more consistent speed, which is generally more fuel-efficient.

The other options do not contribute positively to fuel efficiency. Routes with many hills can lead to higher fuel consumption due to the added strain on the engine when climbing and the potential for increased speed when descending, which can also lead to inefficient driving practices. Driving exclusively on city streets often involves more stops, lower speeds, and a greater need to accelerate, all of which tend to decrease overall fuel efficiency. Finally, while a scenic route might be beautiful, it may not be optimized for fuel efficiency, especially if it includes unnecessary detours or less direct paths.