How Does an Automatic Car work?

automatic car working

Many cars use a form of automatic transmission called a hydraulic planetary automatic transmission, which is also used in some industrial and commercial machinery and heavy-duty vehicles in a scaled-up version. The friction clutch is replaced by a fluid coupling and, depending on the car’s needs, the mechanism specifies a set of gear ranges. Both gears lock when you put the vehicle in park to stop the car from rolling forward or backward.

An automated manual transmission is a less popular choice (AMT). This model couples the clutches and gears of an automatic transmission with a series of actuators, sensors, processors, and pneumatics, also called a semi-automatic transmission. Although offering the affordability and fuel-saving advantages of a manual transmission, AMTs works like an automatic. The driver can change gears manually with this type of transmission or opt for automatic shifting. He or she does not need to use the clutch, which is run by a hydraulic mechanism, either way.

Also, read| All You Need To Know About Automatic Cars

Automatic Transmission Operation

The most popular form of automatic transmission shifts gears using hydraulic power. A torque or fluid coupling converter combines this system with gear sets that provide the vehicle with the desired range of gears. The torque converter attaches the engine to the transmission and transfers power to the gears using pressurized fluid. A manual friction clutch is replaced by this system which allows the car to come to a full stop without stalling.

The pump transforms this power into a transmission fluid that drives the turbine of the torque converter, while the engine transmits power to the pump of the torque converter. This apparatus raises the fluid’s strength and transmits even more power back to the turbine, generating a rotation of vortex power that spins the turbine and the central shaft attached. The power produced by this rotation is then transmitted from the shaft to the first planetary gear collection of the transmission.

What is called hydraulic power has this kind of transmission. An oil pump pressures the transmission fluid, causing the speed to adjust depending on the vehicle’s speed, tire revolutions per minute, and other factors. The gear pump is located between the planetary gearset and the torque converter, where the transmission fluid from the sump is pulled and pressurized. The pump input leads directly to the torque converter housing that is connected to the engine’s flex plate. The transmission does not have the oil pressure required to work when the engine is not operating and therefore the vehicle can not be push-started.

The planetary gear train is a mechanical device in which a series of bands and clutches are associated with the gears. In order to transfer torque from the engine and increase or decrease gears, when the driver switches gears, the bands always retain one gear while spinning another.

How To Change Gears In An Automatic Car?

In order to keep the engine running at an optimal RPM, the automatic car transmission in your car is computer-controlled (revolutions per minute). The transmission automatically moves into a higher gear so that the engine can turn slower under the same power once the RPMs rise above the top limit.

Similarly, the transmission automatically switches to a lower gear when the RPM level decreases above the low limit (the engine turns too slowly) so that the engine turns faster with the same power. You can help to monitor when and how the car changes gears by varying the way you drive.


It is easy to push your automatic transmission to change into a higher gear. Take these measures simply:

  1. Push the gas pedal as hard as you need to raise the amount of engine RPM above the “shift limit” of the transmission. When you push the pedal to the floor to overtake someone or to drive quickly on the highway, you’ll find this happening.
  2. When the transmission moves, you can slightly ease off the gas pedal to stop moving faster than you would like.
  3. Enable the transmission to downshift after your car has driven up the hill. When the engine isn’t needed to work as hard, this will happen automatically.


You can also push the downshift of your automatic transmission into a lower gear. Here is how it should be done:

  1. Ease the gas pedal off when you enter a situation where you’d like to downshift.
  2. Enable the transition to turn to a lower gear.
  3. To retain this gear as long as you would like, keep your speed steady.

Also, read| List of The Top 10 Automatic Cars in India

How To Shift Gears In An Automatic Car?

In instances where you want to shift in or out of low gears, except without the use of a clutch, the procedure will be close to the general approach taken with manual transmission shifting. Never change at a high speed into the low gear while driving.

Do one of the following techniques to change into a low gear:

  1. Let your foot off the gas or brake until you slow to around 20-25 mph if you are in “D,” then resume a steady pace.
  2. Turn to’ 2.’
  3. Slow down a little if the RPMs spike too high (to 4,000 or 5,000 RPMs).
  4. To go to “1”, follow the same method. Until switching, slow down until you are in the 10-20 mph range.

Automatic Transmission Vs Manual Transmission

1- Manual Transmission 

  • Usually, vehicles with a manual or standard transmission are called stick shifts. To change the gears manually as they accelerate and decelerate their car, the driver uses a stick shift. Located on the center console, a connection links the shift lever to the transmission.
  • A manual transmission needs the use of a clutch pedal located on the left of the brake pedal, in addition to a stick shift.
  • The clutch mechanism located between the engine and the transmission is disengaged by engaging the clutch pedal. It prevents power from moving from the engine to the transmission by pushing down on the clutch pedal so you can shift gears. 
  • The driver presses down on the clutch pedal to change gears, shifts the shifter to the desired gear, and then releases the clutch pedal to reconnect the power from the motor to the transmission.

2- Automatic Transmission 

  • While the driver plays an active role in the running of a vehicle with a manual transmission, the driver simply selects D on the shifter in the automatic transmission and the car does all the hard work.
  • The vehicle automatically completes gear changes on its own using fluid pressure. A planetary gear collection is at the center of the automatic transmission.
  • Automatic car transmission fluid is used to provide the pressure required to enable the bands and clutches that decide what gear the vehicle should be in.
  • Not only does this fluid cool and lubricate the transmission’s moving parts, but it helps move the engine.


What type of transmission to get in your next car really comes down to preference; choose the type of transmission that matches your needs. Automatic transmission may be easier to maneuver through stop-and-go traffic than a regular transmission if you do a lot of city driving.

However, you might want to suggest a manual if efficiency and driving experience matter to you. Another thing to bear in mind is whether the car would be driven by other people. If they’re not up for stick shift driving, you’re going to have to stick with an automatic.

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