AMT vs. CVT Transmission: Key Differences Explained

This article explores the differences between Automated Manual Transmission (AMT) and Continuously Variable Transmission (CVT).

AMT Transmission | Automated Manual Transmission

AMT stands for Automated Manual Transmission.

Figure 1: Planetary gear set used in AMT Transmission

• The AMT transmission utilizes gears and clutches, much like a conventional manual gearbox.
• The primary difference lies in the gear shifting mechanism. In an AMT, a control unit automates gear shifts, eliminating the need for manual intervention.
• It automatically changes gear ratios as the vehicle moves.
• AMT eliminates driver effort by automating clutch and gear shifting via a hydraulic process.
• It has a limited number of gear ratios, typically 4, 5, or 6 speeds, similar to a manual transmission.
• The AMT engine may not always operate at the optimal speed for maximum efficiency.

CVT Transmission | Continuously Variable Transmission

CVT stands for Continuously Variable Transmission.

Figure 2: Commonly used CVT type i.e. variable diameter pulley transmission

• Instead of gears, CVT uses variable diameter pulleys connected by a metal belt or chain.
• One pulley connects to the engine, and the other connects to the drive wheels.
• The pulleys are shaped like pairs of opposing cones.
• Cones rotate due to centrifugal force and belt tension.
• CVT is also an automatic transmission, but it offers an infinite number of gear ratios between minimum and maximum values.
• Unlike AMT, CVT does not use fixed gear ratios.
• CVT transmission incurs less power loss compared to AMT Transmission.
• The CVT engine operates consistently at the most favorable speed for optimal efficiency.

Advantages and Disadvantages of CVT Transmission

Advantages:

• Stepless Transmission
• Smooth Drive
• Better Fuel Consumption
• Good Adaptability
• Better Emission Control

Disadvantages:

• Limited amount of torque
• Higher cost
• High wear