The reason why the dual-clutch transmission appeared earlier than the automatic transmission is that its structure and working principle are developed from the basis of manual transmission, but with more precise electronic control systems instead of manual clutch operation. Structurally, the DCT can be seen as a superposition of two sets of manual transmission gear sets, relative to the planetary gear set of an automatic transmission, and the pure mechanical structure is simpler and more stable in performance, with lower maintenance costs.
In fact, even with the development today, the basic principles of the world's top DCT transmissions have not changed. What has changed is only the upgrade of the control system and the further optimization of the structure, such as the increase in the number of gears.
Since the dual-clutch trans uses two clutches to control odd and even gears respectively, alternately shifting, when one gear is in operation, the next gear is already ready to shift, so the shifting speed is fast, and it can be completed within 0.2 seconds.
Some car companies have always insisted on using dual-clutch trans in their performance models precisely because of their advantages in shifting speed. Of course, this also indirectly shows that the dual-clutch trans is not a low-end product.
In recent years, energy conservation and environmental protection have always been the theme of the times, and car companies have also racked their brains to reduce product fuel consumption. Compared with hybrid systems and start-stop systems, choosing DCT is the most economical and effective solution.
You should know that AT transmissions require a hydraulic torque converter to cushion power impacts, which, although smooth, can consume a lot of energy. On the other hand, CVT transmissions are theoretically only fuel-efficient when driving at low speeds. In the event of sudden acceleration, due to the torque protection of the steel band, CVT will drop one or two "gears" more than normal AT and DCT, and you will find that the engine speed rises sharply but the speed increases slowly. Therefore, many CVT models feel not so much that they lack power, but that the CVT gearbox is struggling and can only come slowly.
In contrast, DCT uses clutch hard connection to transfer power, which has the lowest energy loss and higher electronic control level than AT. As long as it is optimized properly, energy loss can be reduced to a minimum. There are testing data that show that DCT can improve overall fuel economy by about 6% compared to AT.
So do you think that the advantages of the dual-clutch will end in the era of the rise of new energy? The fact is that electric vehicles are even more dependent on DCT technology because the dual-clutch structure of DCT is also easy to lay out hybrid systems, which can develop a variety of technical options for hybrid gearbox products.
It can be said that the development of the dual-clutch trans is now very mature, and experienced manufacturers will use multi-round calibration to enable the vehicle TCU to accurately judge driving intentions and gear requirements. The control system will automatically learn and optimize starting strategies to allow the vehicle to start and shift more smoothly. At the same time, some mid-to-high-end models will even introduce hybrid DCT transmission technology, which can save energy while effectively enhancing vehicle performance.