The Difference Between CVT and AT Transmissions

Many people wonder about the differences between Continuously Variable Transmission (CVT) and Automatic Transmission (AT) and which type is the best choice. These two types of transmissions have different standards, structures, and operating principles. Let’s compare CVT and AT together with Huỳnh Châu through the information below to find the most suitable option for your needs!

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Detailed comparison of CVT and AT

1. Definition of CVT and AT

1.1. Automatic Transmission (AT)

Automatic Transmission (AT) is designed to reduce the driver's operational tasks while driving, operating based on complex planetary gears to create gear ratios for vehicles. The AT has been available in the automotive market since 1940, and since then, most models in the market have used this type of transmission.

AT comes in various gear levels like 4-speed, 5-speed, 6-speed, 7-speed, 8-speed, etc. The 4-speed and 5-speed types are widely used in the automotive market, while the 6-speed, 7-speed, and 8-speed variants primarily appear in luxury car models. However, increasing the number of gears isn't just about adding internal components but also involves complexity due to increased size and weight of the transmission, as well as higher production costs.

• The structure of automatic transmission (AT) includes three main parts: the brake band, planetary gear system, and a three-piece clutch system. Among these, the planetary gear system is the most crucial part for stable operation.
• Operating principle: The AT uses a hydraulic torque converter that functions similarly to a clutch to disengage and transmit rotational motion from the vehicle's engine to the transmission. Computers calculate the gear ratio and execute the appropriate shifting based on the car's operating conditions.

The AT transmission operates based on planetary gears.

1.2. Continuously Variable Transmission (CVT)

Continuously Variable Transmission (CVT) is a type of automatic transmission that can create an infinite gear ratio. The main characteristic of CVT is that it does not have fixed gear levels, enabling smooth gear shifts and fuel efficiency.

• Structure of CVT: CVT uses a system of variable pulleys connected by a belt. The CVT consists of three main parts: a high-performance metal or rubber belt, a variable input pulley connected to the engine