Do you know the difference between S-speed gear and D-speed gear of automatic transmission cars? How should you choose when running the highway? How should I switch under different road conditions? Today I will explain the difference between S and D levels in detail.
Many drivers have a habit when driving, which is to use one gear to the end and never actively switch according to the road conditions, making many gears on the transmission a decoration. Little do we know that only the rational use of gears can bring out the real performance of the car and double our driving experience. First, let’s understand the difference between S-speed and D-speed.
P is parking, N is empty, reverse P and D are used to walk the world, but everyone knows that there are several concepts of gears, such as L gear for climbing, S gear for switching to improve power, M gear for manual addition and subtraction, and two low-speed gears 1 and 2. If you only talk about S and D gears, they are both part of the "driving gear". In other words, no matter which one you hang, the car can run forward normally. Although they look very similar, they have many differences in details. The D gear is commonly known as the "economic gear", while the S gear is called the "sports gear" or "overtaking gear". The reason why
is called different and has different definitions is mainly due to the different logic of training when they leave the factory, the different timing of shifting gears, and the performance is very different in terms of fuel consumption, power, and NVH. The training logic of D gear is based on economical and fuel-efficient. When you hang on this gear, the power is sufficient for most cases. The only disadvantage is that the power echoes slowly. In the words of veteran drivers, the car does not move after the fuel is given, and the speed is too slow. Of course, for most drivers, D gear can ensure that every drop of oil in the fuel tank is not wasted to the maximum extent, which is a good thing. The
S setting is different. The training logic is based on the pursuit of a car's sporty sense, in other words, in order to exert the performance of the car as much as possible. When you move to S gear, the power echoes very directly, and you can almost get through with some oil. In the eyes of veteran drivers, this is the state of "man-car integration", full of passion.
Let’s talk about the timing of shifting gears. Since the D gear is mainly fuel-efficient, there are requirements for the engine speed. In principle, the lower the speed, the more fuel-efficient it is. Therefore, the gear shifting time of D gear is to increase if it can be raised, and it will never drag it. No matter which kind of automatic transmission car it is, once it is switched to D gear, the default speed will not exceed 2000 rpm, which will generally change from 1300 to 1800 rpm. The
S gear is just the opposite. It requires the high power at high speeds combined with the overall performance of the car. Therefore, the timing of upshifting will be slightly delayed. The purpose of this is to maximize the torque force of the engine. There are many turbocharged engines now, with a maximum torque speed between 1500 and 4000 rpm, and even the self-priming engine can reach 4400 rpm. You can compare the maximum D gear 2000 rpm. The difference between the two is clear at a glance.
Next, let’s talk about the most concerned thing - fuel consumption.
D gear is undoubtedly an active gear for upshifts. It will deliberately stabilize the engine speed in a relatively economical mode. thermal efficiency will also approach the highest thermal efficiency set by the engine itself. The fuel consumption will naturally decrease; the upshift of the S gear is slower, and the engine speed is higher. Although it is full of power when driving, fuel consumption is relatively sacrificed. In my experience, compared with the two, the fuel consumption per 100 kilometers of the S gear is 1-2L more than that of the D gear. If you often take congested roads, this performance will be completely unlimited, you know.
is right. Many friends don’t understand what the performance of NVH means. I’ll explain it briefly to you. When the car engine is running and working, in addition to providing power, it is also accompanied by high temperature, high pressure, high noise, abnormal jitter, etc. In principle, the higher the engine speed, the greater the probability of these phenomena occurring. When gear D is on, the engine speed is low and the noise itself is limited. With the isolation of sound insulation cotton , our drivers and passengers will not hear it too clearly in the car. At the same time, the abnormal noise and jitter are also relatively blurred, which is called the performance of NVH.Needless to say, the engine speed is increased to more than 3,000 rpm at any time. High noise and car shaking cannot be suppressed. After sitting in the car for a long time, you will feel passionate. Therefore, for ordinary drivers, the NVH performance of D gear is obviously better than that of S gear.
is OK. After talking about some performance differences between them, we need to return to reality and talk about how to choose gears when running highways.
First talk about my experience. When I used S and D gears to run 500 kilometers of highways each, I found that the actual performance of the car is completely different under different gears. I will focus on the four points that everyone is more concerned about: power, fuel consumption, driving experience, and noise.
First: Power performance. When
is hung in D gear to run the highway, the effect is average, whether it is speeding up or overtaking. In general, the acceleration is slow, the oil is deep and there is no obvious feeling of pushing back. But when using S gear, it is obviously faster than the next level, especially at a speed of 120 kilometers per hour. The speed is very fierce and the low-speed pushback feels strong.
Second: driving experience. There is an advantage of running on the highway with D gear on the D gear, that is, the car runs very steadily. If you are the kind of friend who drives step by step and does not overtake if you can, then D gear is obviously a good choice. But you have to understand that if you feel that if you have a car, you must reserve a longer "overtaking vehicle", otherwise your confidence will be greatly reduced. In a word, running on the highway in D gear is not a question of driving desire.
If you are the kind of person who pursues speed and passion, then the driving feeling in all aspects of the S gear is more intense than that in the D gear. It has sufficient power, quick echo, and you can always get it on the highway.
Third: Noise. The most obvious things to run high-speed under
D gear are tire noise and wind noise, while the noise caused by the engine is not obvious. With the window closed, the entire cab is still relatively quiet and comfortable. Run high-speed in S gear. If it is under stable cruise settings, you can hear obvious engine noise. If there is an acceleration, the engine starts to downshift and pull up the speed, and the engine noise will be more than twice as loud. If you are used to D gear, this will really scare you.
Fourth: fuel consumption.
Just now we mentioned that in theory, cars are more fuel-efficient than S gear when driving in D gear, which is relatively true in high-speed driving. The only difference is that under high-speed conditions, the fuel consumption per 100 kilometers of S gear is only 0.8-0.9L more than D gear, which is much lower than the fuel consumption when driving in the city. Everyone can choose at their discretion.
Before, many friends asked me which gear is more appropriate to use when I run the highway? Let me talk about my point of view: Although we all have different understandings of car performance and different driving habits, one thing cannot be denied, that is, veteran drivers are more accustomed to running highways in S gear. Of course, this is also a talk of experience over the years, or the mileage is "feeded".
When driving in the city, the speed cannot be raised. There are many cars and people on the road. In most cases, there is no overtaking. In this case, the D gear can be handled. But the situation of running on the highway changes, and the traffic speed is not slow. You must pay attention to the overtaking speed when running from the auxiliary road to the main road. Friends with sufficient driving experience know that the speed at this time often ranges from 100 kilometers to 120 kilometers per hour.
So one principle is: the city only needs the car to have enough power, while the highway requires strong power. Therefore, for veteran drivers, the S-speed is more convenient to run highways. Let's give an example. If you run at a speed of 100 kilometers per hour on the highway, then when you enter the main road, the speed gradually drops to 60 kilometers per hour. If the rear vehicle does not take braking measures in time, it is easy to hit the head and cause a traffic accident. If you keep moving to S gear, you can speed up more easily. In other words, it will ensure our personal safety to a large extent, so I suggest that you can slowly develop the habit of using S gear to drive on highways.In addition, using S gear at high speed can effectively reduce the production of carbon deposits in the engine. For this reason, we only pay less than 1L of fuel consumption than D gear, which I personally think is worth it.
Below I will give new friends some suggestions for developing S-speed driving habits. Simply put, there is no rigid requirement to use S gear when running highways, but in order to develop good habits, it is recommended to change to S gear in the following situations. When overtaking at
- at high speed, I talked about a lot of theoretical things before, so you can just try it out. When
- is speeding up at high speed, shifting gears, so that everyone can slowly become familiar with the performance and speed increase of the car in S gear, so as not to be in a hurry in the future. It is also recommended to switch to S gear when climbing the high-speed hill. For friends in Sichuan and Chongqing, , Guangdong and Guangxi , Yunnan and Guizhou, there are many mountains in the country and many steep sections. At this time, they still insist on using D gear to climb the hill. The fuel consumption of the car is not worthwhile. In addition, the continuous attenuation of power, I really have no idea. Switching to S level in time can be said to be "removing the disease by medicine".
- when the high-speed downhill. If you use D gear at this time, the long downhill will increase the speed, and the car will run faster and faster. Ordinary braking can easily cause the brakes to overheat, which is not a good thing. You might as well try S gear. You can use the principle of high speed of the engine to use engine braking , and cooperate with brakes to ensure safety.
In short, as an excellent driver, understanding the difference between D and S, and being able to flexibly switch in actual operation is really a compulsory course. Okay, that’s all for today. Which gear do you usually use to drive? Have you mastered the good habit of flexibly using different gears of a car?
