Automatic transmission gearbox has become the mainstream in the world, mainly including AT, AMT, CVT, and DCT.

The early transmission system of AT gearbox is mainly 4AT, and it develops in multiple directions, such as 6AT and 8AT. AT has the characteristics of smooth shifting, good comfort, and a strong ability to transmit power, but its fuel economy is poor and the manufacturing cost is high.

AMT is based on the traditional manual transmission, only the manual operation part is changed, and automatic shifting is realized through an electronically controlled automatic control system. AMT has a simple structure, low cost, and good fuel economy, but its comfort is poor and automation control is difficult.

CVT is a true continuously variable transmission with few parts and small volume and has the advantages of high efficiency and low fuel consumption. It can also be used as a power coupling and transmission to match hybrid vehicles. However, it has disadvantages such as complicated manufacturing, large investment, easy damage to the transmission belt, and short lifespan.

DCT adopts the structure of two clutches, and the shifting process is similar to that of AT. DCT inherits the advantages of good fuel economy and high-quality manual transmission, there is no power interruption during the shifting process, and the shifting comfort is good.

IVT is now actively developed or industrialized by many companies, which may become a new direction for future development.