Take Honda's new Accord as an example. The gearbox of the new Accord has several gears: P, R, N, D, 3, 2 and/kloc-0. P(park) stands for parking gear, which is used when parking (the engine is turned off and idling for a long time)! R stands for reverse gear. I believe I don't need to explain this! N (neutral) stands for neutral, which means the same as the neutral of manual gear. It's for short-term parking! D (drive) means forward gear. In this gear, the gearbox will automatically switch to 1 ~ 5 according to the speed and throttle! 3 is also a forward gear. In this gear, the gearbox will automatically switch at 1 ~ 3, and will not shift up to 4 and 5. It can be used as a restricted gear when the traffic is not smooth, which can avoid jumping between the third gear and the fourth gear! 2 means second gear. In this gear, the gearbox is in the second gear, which is used as a limit gear when starting on wet roads or driving slowly, to avoid jumping between 1 and the second gear, and between the second gear and the third gear! 1 is 1 file. In this gear, the gearbox is in first gear. Other gears that may appear in automatic transmission vehicles include S gear, L gear (such as Honda Fit) and a snowflake button (such as Buick Sail) and OD OFF button on the gearbox. S means exercise. In this gear, the gearbox can shift gears freely, but the chance of shifting gears is delayed, which keeps the engine at a high speed for a long time and increases the power of the vehicle. Obviously, this will increase fuel consumption. L stands for low gear, which should be the same as 1 of the new Accord. In this gear, the transmission will remain at 1 without upshifting. The snowflake button means to start on a wet road. When this button is pressed, the vehicle will start from the second gear instead of 1 gear, so as to reduce the torque output and prevent the vehicle from slipping when starting on wet roads. The OD OFF key indicates that the highest gear is prohibited. Vehicles with this key often do not have D3, because the fourth gear of the highest gear (4-speed gearbox) has been prohibited by pressing this key, which is equivalent to D3.
Tips for using automatic transmission cars
The difference between an automatic car and a manual car lies in the gearbox. Automatic gear is divided into automatic gear shifting and stepless speed change. A car with automatic shift should look like this in use: 1. If you don't like fast friends very much, please don't start in a hurry and speed up quickly. If you start in a hurry, the instantaneous fuel consumption will be high, because the automatic car is engaged with the induction throttle. If the throttle is too large, the upshift will be delayed to match your acceleration, so the engine speed will be high, resulting in high fuel consumption and even engine wear. 2. When waiting for the red light, put neutral, because the automatic car has an initial speed, that is, put D gear, and you will feel the car moving without stepping on the accelerator. If you hang the D gear for a long time, but step on the brakes, it is harmful to fuel consumption and the engine, and it is easy to wear the brake pads. 3. When climbing a mountain, you should choose the right gear. Some friends are used to driving all the way to the D gear, but when climbing, they will obviously feel overwhelmed. This means that you didn't choose the right gear. Generally, 2 or L is a gear suitable for climbing. 4. Try not to slide in neutral. Many people think that neutral taxiing is more fuel efficient, which is a wrong view. Sliding in neutral can not only save fuel, but also cause danger when going downhill or braking.
It should be noted that in some vehicles, the number 2 above the gearbox does not represent single second gear, but 1 ~ 2 gear (such as Buick). When this gear is used, the gearbox will automatically switch between 1 and 2 without upgrading to a higher gear. Automatic gears may not have that many gears. Except for P, R and N (these three gears are necessary for automatic transmission), the forward gear is a D gear (such as FAW mazda 6), and the functions of other gears can be realized one by one through manual mode.
Difference:
There are three types of automobile automatic transmissions, namely hydraulic automatic transmission (AT), mechanical continuously variable automatic transmission (CVT) and electronically controlled mechanical automatic transmission (AMT).
Compared with manual transmission, automatic hydraulic transmission (AT) is quite different in structure and use. Manual gearbox is mainly composed of gears and shafts, which produce speed change and torque through different gear combinations. AT is composed of hydraulic torque converter, planetary gear and hydraulic control system, which realizes speed change and torque change through hydraulic transmission and gear combination. However, due to the automatic shifting of various auxiliary mechanisms, various driving needs can be met, such as parking and reversing. There is also an intervention device, that is, a manual gear lever marked with P (parking), R (rear gear), N (neutral gear) and D (forward gear). The forward gear also provides additional gears of "2" and "1" for use. Because its transmission is divided into several speed ratio sections, it is stepless only in the specified speed section, so AT is actually an automatic transmission between step and stepless.
Design differences: Take Jetta and Fukang as examples. Jetta "Urban Pioneer" adopts a straight-through baffle, and it only needs to push the joystick up and down when shifting gears, while Fukang 988 "Leader" adopts a stepped shift trajectory with six gears, P, R, N, D, 3 and 2 * *, which has the advantage of clear hand feeling, but this design increases the lateral movement of the joystick compared with the straight-through one. Many automobile manufacturers have given up this design, and now the latest automatic transmission cars abroad, such as BMW, Mercedes-Benz S600, S320, Volvo S80, Audi A6, Passat B5 and Toyota New Camry, all adopt straight-through design.
Knowing the working principle of automatic transmission, we can understand that the design of automatic transmission will make D gear automatically switch between 3-2(4-speed or 3-speed automatic transmission car) or 4-3-2(5-speed automatic transmission car) according to the vehicle speed. If you are driving at a slow speed in the city, the automatic gearbox will constantly change between 3-2 and 2-3. Of course, the manual transmission car can be controlled by the driver to shift gears at the maximum torque output point, while the automatic transmission car frequently shifts gears up and down, which will make the driver feel weak.
Because of the historical position of manual transmission in automobile development, manual transmission driving has naturally become synonymous with "driving" (only a few countries in the world, such as Japan, have special automatic transmission driving learning courses and can receive special automatic transmission driver's license after graduation). In our country, all driving schools, without exception, use manual cars to teach driving skills; Therefore, the car with manual transmission is also the most familiar.
The shift operation of manual transmission vehicles completely complies with the driver's will. Drivers who like to save fuel can shift to a higher gear at the lowest speed and the most economical engine speed to save fuel. On the contrary, young people who prefer "sports car feeling" and like "squeezing" vehicle performance can continuously increase the engine speed with lower gears; To get a strong sense of acceleration. Especially because the manual transmission car has the characteristics of high power transmission efficiency, clear gear and arbitrary control. Therefore, it still seems to be the only choice when racing cars and other places have to constantly shift gears up and down to maintain the best driving force at any time. The author once tested the Mitsubishi racing car with WRC entry specifications at Zhuhai International Circuit, and the acceleration created by the manual gearbox combined with the 280 HP supercharged engine was unforgettable for a long time.
In addition to the above characteristics, manual transmission has a series of advantages, such as simple and intuitive structure, relatively low failure rate, low price, good quality, and timely giving drivers the feeling of "I am driving", which is probably one of the reasons why it can dominate the car world with the same "old face" for decades.
The pursuit of comfort is definitely the driving force behind the birth of automatic transmission. With the evolution of the concept of "car", it is based on manual gear. Various more advanced "semi-automatic transmission" and "automatic transmission" are constantly emerging. As a new thing; Because of its outstanding advantages such as convenience, comfort and safety, it has developed rapidly. Especially the appearance of automatic transmission. Not only changed the traditional way of driving cars. It has even changed the traditional structure of "three pedals and one steering wheel", which has a far-reaching impact on the development of automobiles far greater than its own use value.
When there is traffic jam, go in and out of the garage and pass through complicated and difficult sections. Automatic transmission can make every driver cope-it has great charm in itself. Meanwhile. Because automatic transmission saves the shifting operation that always distracts the driver's attention. It is also more conducive to the driver to concentrate on the road ahead and the surrounding environment. Let less skilled drivers have more confidence. Therefore, the accident rate of automatic transmission is generally low. It has higher indirect safety than manual transmission cars.
Automatic transmission not only greatly overcomes the shortcomings in the past, but also makes great progress in fuel consumption, power transmission performance, reliability and cost, reaching the same level as manual transmission. At the same time, it has the advantage that manual gear can never be replaced.