What is the normal RPM for an automatic transmission car?

[DiJames]

Automatic transmission cars typically operate at a normal RPM range of 1800 to 2000 rpm. The engine RPM is directly related to the number of work cycles per unit time or the effective power output of the engine. In other words, the engine's effective power varies with different RPM levels. Therefore, when specifying the effective power of an engine, the corresponding RPM must also be indicated. An automatic transmission generally refers to a car's automatic gear-shifting mechanism. While driving, the control system of the automatic transmission automatically selects the appropriate gear based on the engine's RPM and load, replacing the driver's subjective judgment of timing and gear-shifting operations. Most automatic transmission cars have six gear positions, arranged from top to bottom as: P, R, N, D, S, L.