Compared to CVT, DCT transmission, AT transmission in the end what is better?

20/05/2021

When it comes to automobiles, it is impossible not to mention the "three major components", and when it comes to the "three major components", it is impossible not to mention the very important transmission, and when it comes to the transmission, it is impossible not to mention the mainstream transmission types now. In the development of the automobile industry for more than 100 years, the transmission has changed a lot, from the world's first car - Mercedes-Benz No. 1 was born, the transmission appeared, but then it was not called a gearbox, called the main reducer, it can only go forward, not backward, and there is no gear. The first real transmission in the world was invented by Peugeot in France (1889), while the automatic transmission was first mass-produced by General Motors in the United States in 1940, and it had four forward gears and one reverse gear, the prototype of the 4AT transmission. Today, there are more and more types of automatic transmissions, and the three mainstream ones are AT (hydraulic automatic) transmission, CVT (mechanical continuously variable automatic) transmission and DCT (dual clutch automatic) transmission. So, which of these three automatic transmissions is better?

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图1)

The Aisin 3rd generation 6AT transmission in the GS4, for example, is equipped with two sets of planetary gears, which has the advantage of expanding the locking range and reducing fuel consumption during transmission upshifts. The Aisin 3rd generation 6AT transmission also features a highly efficient energy-saving valve that makes better and more rational use of fuel in starting and idling conditions, and an electronically controlled pump that improves fuel efficiency by 9 percent. In terms of HVH value (sound insulation and noise reduction), Aisin's third-generation 6AT transmission incorporates a long-stroke damper in the torque converter, which effectively suppresses vibration. This, coupled with the wider gear teeth between them, helps the engine maintain low rpm, thus reducing noise. With the development of technology, you will find that the 6AT transmission is now very fuel-efficient. What is the fuel consumption of the 1.5T+6AT powertrain of the GAC GS4? It has a combined fuel consumption of 6.8 L per 100 km. One of the disadvantages of the earlier 6AT transmission is the relatively high fuel consumption, but now? It is basically similar to DCT and CVT transmissions.

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图2)

For those who do not know how to choose an automatic transmission, the AT transmission is a very safe choice. It does not have the problem of CVT transmission lacking driving fun, nor does it have the problem of DCT transmission shifting unevenly and stuttering at low speeds, so choosing a model with AT transmission is also the least regrettable choice. Of course, if you have a deep knowledge of the transmission and feel that the CVT transmission or DCT transmission is more suitable for you, you can also choose according to your own car needs at your discretion. I would say that those who do not know how to choose an automatic transmission can give priority to the AT transmission.

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图3)

Is the Aisin 6AT transmission well matched to the 1.5T engine in the GS4? In fact, one of the advantages of the AT transmission is that it works well with the engine, unlike the CVT transmission, which cannot carry high torque, and unlike the DCT transmission, which may have problems such as stuttering and heating if it is not well matched with the engine, whether it is a large or small displacement engine, a naturally aspirated engine or a turbocharged engine, the AT transmission can work well with them. The role of the torque converter is to buffer the speed regulation, for example, when the GS4 starts and shifts gears, the torque converter can well filter and absorb vibrations and jitters, giving the owner the feeling of smoothness and comfort.

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图4)

The working principle of CVT transmission is very different from AT and DCT transmission, it relies on chain or steel belt friction between two cone discs to transfer torque, this working principle predestines it can't carry large torque, so you will find that CVT transmission is mainly used for small and medium displacement naturally aspirated engines and small displacement turbocharged engines, it runs just four smooth and steady, car owners can't feel it. In fact, it has no gears, the gears are simulated, like AT transmission and DCT transmission have planetary gears, one planetary gear can be regarded as one gear, while CVT transmission has only two cone discs, the chain or steel belt runs to different positions of the cone discs to select several points as "gears", if you select If 8 points are selected, it is simulated 8 gears, if 10 points are selected, it is simulated 10 gears, it does not really realize the "gear change", therefore, the models with CVT transmission are not much fun to drive.

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图5)

In general, among the three kinds of transmissions, AT, CVT and DCT, the most balanced and stable is the AT transmission, which is fun to drive, can also carry large torque, and is not uneven at low speeds. Consider a model with an AT transmission.

相比CVT、DCT变速箱,AT变速箱到底好在哪?(图6)