With the popularity of automobiles, the automobile market is developing very fast, and the most noteworthy thing is the progress in gearbox, from the previous manual transmission models to the current automatic transmission models. Although both manual transmission and automatic transmission have their own consumer groups, automatic transmission vehicles have the advantages of simple operation, more effective improvement of engine and transmission system life, and are more suitable for modern fast life, so many people will give priority to automatic transmission when buying a car.
However, there are many kinds of automatic transmissions, and each transmission has its own advantages and disadvantages in theory, especially the last one. Tutu suggested that you had better not choose it, otherwise there is no place to regret it. Let’s take a look.
Generally, for convenience, everyone calls it AT gearbox, which is composed of hydraulic torque converter, planetary gear mechanism, electronic control system and hydraulic control system. Among them, the hydraulic torque converter is equivalent to the clutch on the manual gearbox, and the power is transmitted by the high-speed movement of the liquid. Because there is liquid between parts, the stability is good; However, because it is not a rigid connection, the problem of power loss is easy to exist.
The core of automatic transmission is to realize automatic gear shifting, which can automatically shift into different gears by manipulating the accelerator pedal, but the transmission efficiency is lacking, resulting in relatively high fuel consumption. As for whether this kind of gearbox works well or not, it depends on the number of gears and shifting logic. For example, the previous models were generally 4AT, but now they are more common at 6AT, 7AT, 8AT and 9AT.
However, the more gears, the better. It depends on the shift timing set by the gearbox manufacturer, which is often called shift logic. This timing is related to engine speed, accelerator pedal degree and vehicle speed. A good automatic gearbox, with sensitive shifting and reasonable logic, can also run a good fuel consumption performance.
This kind of gearbox also uses hydraulic torque converter to transmit power, similar to AT gearbox. However, in the gearbox part, the steel belt sandwiched between two cones is used to realize power transmission by clamping force, which is often used in Japanese cars.
There are many advantages. The first one is smoothness, which is smoother than AT. The second is fuel saving, because stepless speed change can keep the engine speed in the highest combustion efficiency range and the most economical speed range, which naturally saves fuel; The third advantage, low cost, CVT gearbox only needs a few thousand dollars. There are also disadvantages. First, it can’t bear too much torque, because the steel strip can’t stretch, it will slip and respond slowly to speed changes; The second is that the quality is average, the mileage is too long, and the steel belt may slip, resulting in damage to the gearbox and need to be overhauled.
Powershift has been widely used in the automobile field, ranging from Bugatti, Koenigsegg and other supercars to Great Wall, Geely and other domestic vehicles. The first is that it can bear large torque, because the clutch is hard-connected, and it is not afraid of large torque. Now many high-horsepower models have also used DCT dual clutch; Second, the shift speed is fast; The third is to save fuel, because the clutch connection and the gear connection are hard connections, and will not lose too much power.
However, the production cost of dual clutch is high, and the adjustment of each family is also different, and there may be setbacks in specific operation. The recall of Volkswagen DSG, which made a lot of noise in recent years, is also one of the shortcomings of DCT gearbox, that is, frequent shifting can easily lead to overheating of some modules in gearbox, which leads to failure and damage, but this problem has been improved in recent years.
Tutu’s advice to everyone is that when choosing DCT dual clutch gearbox, don’t choose dry type if you can choose wet type.
Also known as semi-automatic gearbox, AMT is essentially a manual gearbox, which is just a computer to help shift gears, that is, ECU completes two actions of operating clutch and gear selection, which liberates the driver’s operating intensity to the greatest extent.
The biggest advantage of AMT gearbox lies in its cost. Compared with the traditional AT automatic gearbox, the internal structure of AMT is much simpler, which is common in all kinds of entry-level cars. However, the shift quality of AMT gearbox is average. When shifting gears, there is obvious frustration. This is because the AMT gearbox will rudely disconnect the throttle to supply oil when engaging the clutch. Therefore, when you buy a car, it is best not to choose this gearbox.
Seeing this, many friends may have a question, which gearbox is better? If the elimination method is used, the AMT gearbox has poor driving experience due to many faults; There are many problems with CVT gearbox in the later period. The king of family car has frequent gearbox problems, and at the same time, it can’t bear large torque. However, CVT gearbox can’t be seen in high-end cars, which shows that CVT gearbox is special for low-end cars.
The remaining AT and DCT gearboxes are relatively good, among which AT gearboxes have smooth acceleration and deceleration and good driving experience. In terms of market share, AT gearboxes are used in low-end, high-end and ultra-high-end markets. 80,000, 500,000 BMW and millions of Rolls Royce are all AT gearboxes. In terms of quality, AT gearbox is very reliable and has the same life as the car. In terms of power matching, whether it is a small horse power self-priming engine or a V12 engine, the AT engine can match. Therefore, it is best to give priority to AT gearbox. Do you think it makes sense?
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