What is an Automatic Transmission Car?

[JasonLynn]

An automatic transmission car is a vehicle that uses an automatic transmission (AT) to regulate speed. While driving, the control system of the automatic transmission automatically selects the appropriate gear based on the engine's speed and load, replacing the driver's subjective judgment of timing and gear-shifting operations. Automatic transmission cars typically use a hydraulic transmission device to replace the mechanical clutch of manual transmission cars, hence there is no clutch pedal. When the engine speed is low, the torque transmitted by the fluid is limited and insufficient to propel the car forward. When the gear lever is placed in the drive position and the brake pedal is released, as the accelerator is pressed and the engine speed increases, the transmitted torque increases, pushing the car forward.