Automatic, CVT or automated transmission: which is best? | Estadão Mobility | Mobility Workshop

Automatic transmissions already represent the majority of cars sold in Brazil. It is worth highlighting, however, that, when talking about automatic transmissions, CVT and automated technologies are in the same context, although they present certain differences.

The automatic transmission itself accounts for 40% of sales. The CVT occupies a 21.5% share of the market, while the automated transmission has a 7.5% share, according to automotive consultancy Jato Dynamics.

“The systems have advantages and disadvantages between them, depending on the vehicle’s application”, says Marco Barreto, professor of Mechanical Engineering at Fundação Educacional Inaciana (FEI).

Discover the main characteristics of each of the three transmissions.

Automatic transmission

The favorite of most drivers, the automatic transmission works with a torque converter – which converts the movement of the engine to the transmission – and small clutch assemblies that perform the changes.

“The automatic transmission gives the driver a greater feeling of comfort, due to the smooth shifts, but has low efficiency in some operating conditions”, reveals Barreto.

For the most appropriate connection with the engine, the torque converter uses hydraulic pressure to manage the transfer of energy between the engine and gearbox. In general, it has lower performance than manual transmission.

The automatic transmission’s torque converter assumes the clutch function when the vehicle is parked with the lever in position D (drive). This component has oil internally and does not suffer from wear.

The electronic management of the automatic transmission allows the management of these changes, including economy or performance modes, by altering shift times.

CVT transmission

The CVT is a type of automatic transmission and its acronym in English stands for continuously variable transmission. While the conventional automatic transmission has a torque converter, the CVT has conical pulleys, of variable diameter, generally connected by a metal belt or chain.

As there are no gears, the set offers infinite movement ratios, that is, they depend on how the belt or chain moves. Some manufacturers, however, have programmed their CVT transmissions to simulate gears, as in conventional automatics.

“The CVT, in naturally aspirated internal combustion engines, tends to have lower fuel consumption, but the sensation of constant engine rotation can cause discomfort when driving”, says the professor.

Although the CVT has a simpler construction than the traditional automatic transmission, the maintenance cost can be higher, because most of the spare parts are imported. The services performed during periodic inspections are similar, including, for example, changing lubricants according to the manufacturer’s recommendations.

Automated exchange

The automated transmission is a cheaper and simplified version of the automatic. It’s like a manual transmission that works with a part called a hydraulic actuator.

“Automated transmissions have lower production costs; on the other hand, they cause some unidentified discomfort in other transmissions”, highlights Barreto.

The system works with an electronic module and an electromechanical actuator, which directly interfere with gear changes. It activates the so-called shifter to activate the gears, activating the clutch automatically. The performance, however, does not match the same speed as the automatic transmission, which leaves many drivers upset. The advantage of automated transmission is that it eliminates the need for a complex, hydraulic transmission or a CVT. Therefore, only the electromechanical actuators, the selector lever and the electronic management module are used.

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Author: Eric

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