Car Transmission system

Car Transmissions Explained | CVT, DCT, IMT, AMT, Manual, Automatic

Car Transmissions Explained | CVT, DCT, IMT, AMT, Manual, Automatic

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  • Post last modified:April 30, 2023
  • Post category:Cars
  • Post comments:3 Comments
  • Reading time:12 mins read
Car Transmission system

The Transmission system is one of the most crucial parts of a vehicle’s power distribution system from the engine. Different types of transmissions are unique for different scenarios while others just don’t cut it. Basically, there are two main transmissions from which the rest arise from; Manual and Automatic.

In order to explain the rest, we first have to start from the basics. Essentially, the main differentiating factor between a Manual car and an Automatic one is the presence of a driver operated clutch in a Manual transmission vehicle. These cars have three pedals; the brake, clutch and gas pedal while in an Automatic car, you only get two pedals; the gas pedal and the brake pedal.

Manual car vs Automatic car Pedals

The main function of a transmission is essentially to distribute power from the engine to the wheels. The transmission system in most vehicles, is located between the engine and the drive shaft which transfers torque to either axles depending on the car’s architecture then to the drive wheels.

With that out of the way, there are six different types of transmissions which will further be discussed in this article;

1. Automatic Transmission. (AT)

2. Manual Transmission. (MT)

3. Continuous Variable Transmission. (CVT)

4. Dual Clutch Transmission. (DCT)

5. Intelligent Manual Transmission. (IMT)

6. Automated Manual Transmission (AMT)

1. Automatic Transmission.

Automatic Transmission gear lever

As explained earlier, an Automatic car only comes with two pedals; the Gas pedal and the Brake pedal. One myth people often throw around, is that an Automatic car does not have a clutch, which is down right crap. They do have a clutch, multiple ones in some vehicles, with the difference being that they are computer operated unlike in Manual cars which require human input.

Automatic vehicles have recently taken over the market overshadowing their Manual counterparts due to three simple reasons. They are dead easy to operate, they require less driver input meaning a relatively enjoyable driving experience in some drivers and finally, smoother gear changes which translates to better comfort of both the driver and passengers.

Automatic car pedals

This is not to say that they don’t have downsides because they have their fair share of cons. One, they require more maintenance as compared to manual cars and some ‘seasoned’ drivers prefer manual transmission due to the simple fact that they are more fun to drive. Of course preferences vary from person to person.

2. Manual Transmission.

Manual Transmission Gear lever

Manual Transmissions are becoming less and less common these days but that’s not to say that you can’t own one. So, how do these types of vehicles works? Well, as mentioned earlier, Manual transmission vehicles come with three pedals; the Brake pedal, the Gas pedal and the Clutch pedal.

In a Manual vehicle, the driver is responsible for making gear changes in response to the speed in which the car is moving. Typically, higher gears are used when the car is moving really fast while the lower gears are used when a vehicle is moving at a lower speed and when high amounts of torque is needed. Lower gears are better in scenarios such as launching a vehicle which heavily relies on torque, when stuck you are stuck in mud, when traveling uphill etc.

So, how does the clutch in a Manual vehicle work? I am glad you asked. Basically, the engine burns fuel to produce rotational force; Torque. For the torque to get to wheels, it needs a transmission system, in this case, a Manual one. Remember the rotational force from earlier? Well, this rotational force is exerted on the crankshaft, which is in turn connected to the transmission system.

Manual Transmission Pedals

The clutch is positioned between the Engine, Fly wheel and the set of gears in the transmission. Inside a clutch system, we have a pressure plate which engages or disengages the engine’s motion from the wheels. So, when you press the clutch pedal, you are essentially exerting a force on the pressure plate. To change gears, you have to press the clutch to disconnect the engine’s motion from the wheels otherwise you risk damaging the whole transmission system.

Manual transmission are much preferred by seasoned drivers and ‘boy-racers’ due to the control of gears by the driver which sends adrenaline rushing through their bodies. In addition this, they require less maintenance and they tend to last longer than their Automatic counterparts.

3. Continuous Variable Transmission. (CVT)

CVT Transmission Gear Lever

Continuous Variable Transmission vehicles are by far the most unique of the bunch. This is because they don not use gears. Instead, they use a set of pulleys. That’s right, these cars use pulley belts to channel engine torque to the drive wheels.

A CVT is basically an Automatic vehicle with no gears. But how do these vehicles work? Well, a CVT consists of two cones at each pulley connected by a chain belt. One cone is connected to the engine while the other one directs power to the drive wheels. The cones move in a manner which either increases or decreases the diameter of the chain belt. This provides an infinite gear ratio and is often controlled by the on board vehicle computer.

CVT Transmission

Subaru(s) and Nissan(s) are notorious for producing CVT transmission vehicles. In fact, Subaru produces one of the best Continuous Variable Transmissions in the industry. But why would you want a CVT vehicle. Well, for starters, they provide a comfortable ride for a daily commute vehicle. Moreover, they provide great fuel efficiency and are more suitable for smaller 4-cylinder engines.

4. Intelligent Manual Transmission. (IMT)

Intelligent Manual Traansmission

This is one of the least common transmissions of the bunch and frankly speaking, I have never come across an IMT in real life. Any way, these type of vehicles offer the conventional Manual stick shift, with the ability to switch gears when need be. However, they do not have the conventional clutch with the three pedal setup. Instead, it relies on a single clutch modulated by an actuator.

Simply put, an Intelligent Manual Transmission vehicle is a Clutch-less Manual vehicle. It is important to note that an iMT vehicle cannot, shift gears on its own. It still requires human input. One of the downsides to this type of transmission is that, the gear shifts are not as smooth as in an Automatic but in turn, you get a clutch-less Manual car. Some consider this system the best of both worlds, but in the real sense of things I’d suggest making up your mind and going for either an Automatic or Manual vehicle.

5. Dual Clutch Transmission. (DCT)

BMW DCT Gear Lever

As the name suggests, a DCT is a type of automatic transmission with two clutches instead of one. They are typically found in high end sports and racing vehicles due to their lightning speed ability to shift gears which a conventional automatic or manual just can’t match.

In a DCT vehicle, there a two clutches for both odd and even gears which enable faster gear changes. In addition to this, DCT vehicles can either be operated Automatically by the system or Manually via the paddles on the steering wheel or manual mode on the gear selector.

Dual Clutch Transmission diagram

BMW is notorious for using this kind of transmission in their high performance M cars. A very good example is the much loved F80 BMW M3 which had a dual clutch system before they shifted over to a torque converter in the latest G80 BMW M3.

6. Automated Manual Transmission. (AMT)

Automatic Transmission Gear lever

This type of transmission is also known as a torque converter automatic vehicle. Just, like in the Dual Clutch Transmission, an AMT can be operated Automatically by the on board computer or manually by paddle shifts or a manual mode in the gear selector in some vehicles. But unlike in a DCT, an AMT does not come with Dual Clutches. Instead, the single clutch is operated by actuators and sensors.

In addition to this, the gears are pre-programmed with an RPM range in the ECU. This simply means that even if you are in manual mode, the on board computer can still automatically up-shift or downshift when need be. An AMT can still be used in relatively fast cars and high end luxury vehicles due to their smoother gear changes and sportier feel.

Final Thoughts.

Futuristic Car

These are the six main types of transmission systems used in different cars for different scenarios. I hope this article has finally shed some light on transmissions as well as their use cases. Be sure to share this article if you found it helpful and leave a comment if you have any question, suggestion or inquiry. Cheers!!

This Post Has 3 Comments

  1. Carson Anekeya

    Great technology, a good read.

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