RPM meter is known for telling the driver the rounds per minute.Here you go with some uselful info:D
Revolutions per minute (abbreviated rpm, RPM, r/min, or r·minsup−1/sup) is a unit of frequency: the number of full rotations completed in one minute around a fixed axis. It is most commonly used as a measure of rotational speed or angular velocity of some mechanical component.An automobile's engine typically varies between 700 and 7000 r/min (12–120 Hz) though some cars’ engines can spin as quickly as 11,000 r/min (180 Hz).