Automated Manual Transmission: Auto Gear Shift (AGS)

One of the main reasons people don’t buy automatic transmission cars is that they are not fuel-efficient. Manual cars are way more fuel-efficient than automated transmission cars, and those offer more pleasure to drive. But now automobile manufacturers came up with a new technology called ” Automated Manual Transmission” that can offer the convenience of an automated transmission but the fuel efficiency of a manual transmission.

What Is Automated Manual Transmission

Automated Manual Transmission ( AMT) is often called Semi-Automatic Transmission (SAT) or Clutchless Manual Transmission (CMT). In India, Maruti Suzuki uses the same technology with the name ” Auto Gear Shift.”

In the automated manual transmission, there is no clutch pedal for the driver. So why not call it automatic transmission. Confusion. Right?

I said there is no clutch pedal. But there is a clutch in automated manual transmission similar to any manual transmission. It has the same type of gearboxes as any other manual transmission. The only difference is that the clutch functionality is automated by using actuators and sensors.

automated manual transmission
Manual Transmission vs Automated Manual Transmission
Credit :

Since only the clutch function is automated and everything else is similar to a manual transmission, it is called automated manual transmission.

Automated Manual Transmission vs Automatic

You might already hear about hydraulic automatic transmission and Continuously Variable Transmission (CVT). CVT is the true automatic transmission used in almost all automatic cars nowadays.

In CVT, a car gets a torque converter instead of a regular clutch and gets a planetary gear train instead of a standard gearbox. Don’t get confused if I say that CVT does not have a normal clutch, but it has a clutch inside the torque converter.

In the CVT, you will get an infinite gear ratio as it’s a traditional belt drive system. You won’t feel the jerk as the gear ratio is getting changed continuously. I can say the traditional automatic transmission is far more refined and smooth to drive in a nutshell.

In an automatic manual transmission, you get the gearbox, clutch, and everything like a manual transmission. Only the clutch functionality is automated. You may feel like you are driving an automatic car, but you can always feel the gear shifting jerk. The automatic manual transmission does not offer an infinite gear ratio. What does that mean is that the car will take its own time to change the gear rather than when it is really required.

Automated Manual TransmissionAutomatic Transmission
Uses a manual gearboxUses a torque converter
Slow to respond against the set RPM There is no such predefined RPM.
Gear shift can be sensed by the driverThe gear shift is smooth and can not be felt by drivers
Sometimes comes with dual-mode option( Manual + Automatic manual transmission)No option for a manual gear shift stick
Very unpleasant to drivePleasant to drive
Fuel efficientNot very fuel efficient
Cheaper to buy and maintainCostlier than an automated manual transmission

How Automated Manual Transmission Works?

As I said earlier, an automated manual transmission is basically a traditional manual transmission with the clutch function automated. Some sensors detect the engine RPM, and based on that, it sends a signal to actuators, and actuators, in turn, operates the clutch for you. The gear shifting is also automated. These actuators use a hydraulic system and computer linked with the ECU ( Engine control unit) to do all these automated processes.

The transmission will only change gear when it detects the preprogrammed RPM ( Revolutions per minute). For example, in manual transmission, you may change gear from 1st to 2nd when the RPM is 1500. But in the automatic manual transmission, the RPM range is defined by the car manufacturers. For example, they may set the car to shift from 1st gear to 2nd gear at 2000 RPM. You don’t have any control over that.

Some cars come with a manual stick in automated transmission cars. What that means is that if you want to control the car manually, you can do that, and if you hate to press the clutch pedal, you can set it to automatic. So you are getting both the flavors from the same transmission box.

Types Of Automated Manual Transmission

There are two types of automated manual transmission

  • Single clutch automated manual transmission
  • Dual-clutch automated manual transmission

Single clutch automated manual transmission is what we have discussed so far in this article. There is a single clutch in the transmission that, when engaged, shifts gears irrespective of whether it’s an odd gear set or even gear sets. This transmission box type is old, lurch-prone, and not very pleasant to drive.

Dual-clutch automated manual transmission or dual-clutch technology ( DCT) in manual transmission uses two different clutches for odd and even gear sets. These are much better to drive and lurch free.

What Is Auto Gear Shift ( AGS)

This is a term that Maruti Suzuki India uses for its automatic manual transmission cars. AGS uses the same automated manual transmission technology, but they gave a different name just for marketing purposes.

automated manual transmission

You may notice that they call it Auto Gear Shift and not “Automatic,” Right? Only the gear shift is automated, like in the case of an automated manual transmission. It does not use any torque converter like any other automatic transmission.

Did you notice the “M” symbol with a + and sign. That is for manual transmission mode. When you switch to “M ” mode, your car is like any other manual transmission car.

Advantages Of Automated Manual Transmission

  • There is no clutch pedal for drivers. So you will feel like you are driving an automatic car
  • Often comes with dual-mode ( Manual and Automated Manual Transmission)
  • The transmission box design is relatively simple compared to automatic transmission
  • Reduce the fatigue of drivers
  • Cheap to buy a car with automated manual transmission compared to automatic transmission
  • Similar fuel efficiency like manual transmission cars

Disadvantages of Automated Manual Transmission

  • Predefined RPM to shift gears. This means only when the engine reaches that RPM level gears will be shifted
  • It does not offer an infinite gear ratio
  • Jerky and absolutely painful to drive at low RPM
  • Maneuver in highway traffic is a big pain. The gear won’t shift when you need it.
  • Does not use a torque converter

Final Words

If you want to enjoy the convenience of automatic cars but don’t want to spend more on pure automatic cars, you can go for automatic manual transmission cars. But you will miss the fun of driving a manual car and a pure automatic car. It is a compromise between manual transmission cars and automatic transmission cars.

I could able to give you a basic idea about automated manual transmission. If you have some questions, you can always write that in the comment section, and I will be happy to help.

You may also like to read: Different types of engines


A 2004 batch Mechanical Engineering graduate From NIT, Agartala. Close to 16 years of experience in the field of consumer electronics and appliances domain as a Sr. Design Engineer and Team Leader in India and the United States. A GD&T practitioner, with expertise in Lean Manufacturing and Six Sigma. Crazy about exploring CAD-CAM tools and in his free time love to go for a ride with his champ, Rian.