Which two indicators can inform you when to shift gears?

Engine speed (rpm) and road speed (mph) are key indicators that inform a driver when to shift gears while operating a vehicle. The engine speed, measured in revolutions per minute (rpm), helps indicate how hard the engine is working. As the engine approaches higher rpm, it signals that shifting to a higher gear may be necessary to maintain efficiency and prevent engine strain.

Road speed, measured in miles per hour (mph), also plays a significant role. When a vehicle is traveling at a certain speed, especially at lower speeds, it may require a lower gear to maintain adequate power and speed. As the vehicle accelerates and reaches higher speeds, shifting to a higher gear improves fuel efficiency and reduces engine wear.

This combination of engine speed and road speed helps the driver determine the optimal time to shift gears, ensuring safe and efficient operation of the vehicle.