We did a story earlier about “Whether I should buy a manual or automatic transmission car” in which we shared the advantages and disadvantages of Manual VS Automatic transmission. In past few years, the technologies have advanced much beyond the conventional thinking to bring the best features of both of them in a new Auto Gear Shift or EZ Drive or Semi-Automatic or Automatic Manual Transmission (AMT) system. I will not try to bore you here with too much technology terms, but will try to explain it in simple language here. But to understand the differences and what AMT is, lets see what is a conventional Manual Transmission and a conventional Automatic and then lets look at the new Automatic Manual Transmission (or AMT) or Auto Gear Shift system.
Why Do We Need Transmission System?
Before we dive into details, transmission is a part of the car which connects the engine to the wheels. When car speeds up, the engine can not speed up in the same proportion, so there are gears involved which match the engine speed to the wheel speed so that we can drive faster or slower than the engine speed.
What is Manual Transmission System?
When the driver manually selects at which gear (depending on speed) should the car run, and he/ she changes the gears using a clutch, it is a manual transmission. Clutch is the part which connects the engine to transmission, when driver needs a gear change, he/she presses clutch pedal/lever, which disconnects the wheels and engine, he/she changes the gear and releases the clutch which puts the wheel back in connection with the engine. With changed gear, the speed range of the car changes. This is why when we go faster, we put higher gears. The reason behind this is that engine has only a limited speed range. I will not go further into tech here for the sake of our non-engineer readers here.
- Simple system and easy to maintain
- Low cost
- Gives high fuel economy as there are no losses
- Tiresome in stop and go traffic
- Gear shift speed depends on driver prowess, and some may not be able to extract the maximum out of the car
What is Automatic Transmission System?
In automatic transmission, there are again gears like we have in manual, but in this case, instead of conventional clutch, there is an automatic mechanism called torque converter which works with some fluids and turbine mechanism (will not go in its details here). When the speed of the car changes, the torque converter helps change the gears automatically, so the driver does not have to operate clutch lever to change gears.
- Easy to operate
- Freedom from manually selecting gears
- Enthusiastic drivers like manual better than automatic as it offers more flexibility and manual control
- Torque converter has transmission losses (energy loss) which causes loss in fuel economy
- More complex system than manual, so its more expensive to maintain / replace
Video: Automatic Transmission Explained
What Is Auto Gear Shift EZ Drive or Semi-Automatic or Automatic Manual Transmission?
Clutchless transmission is almost the same at the manual transmission, but in this case, the clutch operation is automated. Like the manual transmission system, gear has to be selected by the driver only depending on his/her selection, he/she has to change the gears, but without operating the clutch lever. In this case, an electronically controlled (microprocessor based) system is used to identify when the driver changes the gear, an electrically operated (power operated) system depresses the clutch automatically when the gear is changed. The components of the system are almost same as manual transmission, just than an automated clutch mechanism is added to it for the comfort of the driver. The most tiring part of a manual transmission is to operate the clutch lever, once that it eliminated, the effort is reduced to just selecting and changing gears. In nutshell, it takes out the tiring part of the driving from the manual transmission and still leaves the choice of changing gears with the driver. One such system called eClutch has been developed by Bosch which works on the same principles.
- Freedom from operating the clutch lever
- Very comfortable for stop and go traffic
- Better mileage than automatic transmission (less transmission losses)
- Lower cost than automatic transmission
- More expensive than manual transmission
- Not widely available
Video: Suzuki Suto Gear Shift System
What Are Other Alternatives? Dual Clutch Automatics?
If cost of the transmission can be overlooked (such as in performance or luxury cars), there are even better systems which are available. These systems cars called Dual-Clutch Automatic transmission systems. These are generally equally or more expensive than the conventional automatic systems, but they are really good in terms of efficiency as well as performance. The way they operate is that instead of one, they use two-clutches which connect with even and odd number of gears. When the car speed changes, the transmission system (controlled by a microprocessor unit), selects a gear (depending on load, speed, driver’s throttle input and many other factors). After selecting the gear, the system automatically engages that gear in almost no time as it has two clutches, so one clutch is dis-engaged and other is engaged. This process is very fast, efficient and comfortable to use, but since it involved more components and electronics, it is more expansive than all other 3 which are mentioned above.
- Very comfortable for any kind of traffic
- Better mileage than automatic transmission (sometimes better than manuals)
- Better performance as gear shifts are fastest compared to other systems
- More expensive than all other transmission systems (for now)
- Not widely available