What action should be taken to optimize fuel efficiency?

Maintaining steady speeds is the most effective action to optimize fuel efficiency. When driving at a constant speed, the vehicle's engine operates more efficiently, minimizing fuel consumption. Rapid changes in speed, such as frequent acceleration or deceleration, can lead to increased fuel usage because the engine has to work harder to reach higher speeds repeatedly.

Driving at high speeds also tends to reduce fuel efficiency, as air resistance increases significantly, requiring more power and, consequently, more fuel. Furthermore, increased idling time can waste fuel without any benefit since the engine consumes fuel while not moving the vehicle. Consistent, moderate driving allows the engine to perform at its optimal level, benefiting overall fuel efficiency.