What does a tachometer indicate?

A tachometer measures the speed of rotation of the engine, typically expressed in revolutions per minute (RPM). This tool provides crucial information to the driver about how hard the engine is working. By monitoring the RPM, drivers can optimize engine performance and efficiency, avoid over-revving, and make better decisions regarding gear changes in manual vehicles. Understanding the tachometer is essential for maintaining proper engine function and preventing potential damage caused by excessive engine speed. It plays a significant role in driving skills, particularly in performance or racing scenarios where precise control of engine output is crucial.