Two brothers with opposite personalities.
The dual clutch gearbox was first used in racing cars. In the' 80s, Porsche? 962C and Audi sport? quattro？ S 1？ Remote control racing is the first racing car that really has this technology. In principle, dual clutch is relatively simple, which is about equal to AMT gearbox (AMT is the simplest automatic gearbox scheme, only suitable for cheap cars. ) add another set of clutches. However, the beauty of this extra clutch is that the two clutches control the odd and even gears respectively, and the gear of the next gear is prepared in advance before shifting, so that the effect of gapless shifting can be achieved, so the dual clutch is essentially a technology to improve shifting speed.
The earliest concept of CVT gearbox appeared in Leonardo da Vinci's manuscript. Different from other gearboxes, it does not use gears to transmit power, but uses belts or steel belts to connect two sets of bevel gears similar to cone barrels to control the speed of wheels. The principle is very similar to the chain drive of bicycles. However, because the bevel gear is smooth, there will be no feeling of stepping on the gear, which means that CVT is theoretically adjusted to an infinite number of gears.
Summary: Double clutch is suitable for sports; CVT continuously variable gearbox is suitable for home use.
More important than features is their cost.
As far as cost is concerned, dual clutch is lower than CVT gearbox, because it can be on the same production line as manual transmission, and a dual clutch part can basically be produced and assembled in China, and because its structure is close to manual transmission. Moreover, CVT has to import foreign core components (transmission steel belt). Therefore, some manufacturers use dual clutch instead of CVT, and the low price of dual clutch is at work.
The steel belt of CVT has always been controlled by Bosch, which is a cost that every OEM can't avoid. Only Chery independently develops and produces CVT gearboxes in China. Dual-clutch gearbox does not have so many thresholds in patents, so it has become the first choice for manufacturers to develop.
Who is easy to maintain these two gearboxes?
Is the double clutch easy to break down? Maintenance and replacement of components; CVT is not easy to break down? Maintenance and replacement of components
The two gearboxes are very different in the later maintenance. At present, the dual-clutch gearbox cannot be repaired externally, and the 4S shop only provides replacement service. However, at present, more faults of the dual clutch appear at the program level, which are mainly manifested in (engine idling, no acceleration in refueling, and delay in entering the gear). 4S workshop has no ability to deal with this kind of fault, and it is mainly adjusted by the main engine factory. So its timeliness is very poor, and many problems are solved by waiting for recall.
However, the failure rate of CVT gearbox is much lower than that of dual clutch. Most of the problems are that with the increase of service life, the two key components, cone wheel and steel belt, have problems. The maintenance of the 4S shop is also very simple and rude, and the assembly is directly replaced, because the steel belt and bevel gear are the bulk of the cost of a CVT gearbox, and no auxiliary machine factory can supply accessories.
Which is the most important for consumers, reliability or safety?
To analyze the safety of these two gearboxes, we should return to the working principle. The quality of dual clutch gearbox is largely determined by the logic of the program, that is to say, whether the computer can properly prepare the required clutch gears for combination is the key to whether the dual clutch can give full play to its advantages, because its working principle is similar to that of manual gears. If there is something wrong with the program setting, the problems that the novice manual shift driver will encounter, such as long-term power interruption, overheating of the clutch, abnormal noise jitter and abnormal wear, will all appear on the dual clutch, which is also the reason that will happen in that year.
On CVT, unpredictable faults and safety hazards will be much less. Because of its simple structure, most CVT gearboxes are mainly repaired by replacing two core components, namely steel belt or bevel gear. Its reliability and safety are mainly related to the design and service life of transmission steel belt, so CVT has higher safety in the life cycle of gearbox. But some old cars may not be.
Of course, dual clutch is not without advantages.
In recent years, the evaluation of dual clutch has been worse than freezing point. Objectively speaking, compared with other automatic gearboxes, dual clutch still has its outstanding advantages in sports. I still remember that when Volkswagen promoted dual clutch, shifting speed was one of its main selling points. Fast shifting speed and transmission efficiency close to manual gear make the dual clutch stand at the apex of the sports car field, otherwise Porsche's PDK dual clutch will not always be talked about by fans.
Car detective summary: which is better, dual clutch or Cvt? In order to improve the reliability and smoothness, manufacturers who insist on dual clutch are lengthening the response time of shifting. In order to improve driving pleasure, CVT gearbox is simulating the gear of traditional AT gearbox. At the same time, many conscientious manufacturers in China regard this as a very sad thing in the eyes of car selection detectives. Just like rabbits learn to swim and give up their best strength to catch up with the natural advantages of AT gearbox, such a strategy will naturally be lost by AT gearbox.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.