Evaluation index of automobile performance What parameters does automobile performance relate to? Usually used to evaluate automobile performance are: power, fuel economy, braking, handling stability, ride comfort and passability. The power of a power car is expressed by the average speed that the car can reach when driving straight on a good road. Automobile power is mainly evaluated by three indicators: the highest speed; The acceleration time of the car; The maximum slope that a car can climb. Maximum speed-refers to the highest speed that a car can reach when driving on a smooth and good road. The larger the value, the better the power. The acceleration time of a car-that is, the acceleration ability of the car, also known as the ability to reflect the speed, has a great influence on the average driving speed of the car, especially for the car. It is often expressed by the acceleration time of starting in place and overtaking. Climbing ability of a car-the maximum slope that a car can climb with a full load. Fuel economy The fuel economy of a car is usually measured by the fuel consumption of the car 100 km under certain working conditions or the mileage that a certain amount of fuel can drive the car. In China and Europe, the unit of automobile fuel economy index is L/ 100km, while in the United States, it is expressed by MPG or mi/gall, that is, the mileage per gallon of fuel. Fuel economy is related to many factors, such as driving speed. The fuel consumption of a car is the lowest when driving at a medium speed close to low speed, and it increases rapidly with the increase of vehicle speed at high speed. In addition, the maintenance and adjustment of the car will also affect the fuel consumption of the car. The ability to stop the car for a short distance and keep the driving direction stable and keep a certain speed on a long slope becomes the braking of the car. The braking performance index of automobile mainly includes braking efficiency, constancy of braking efficiency, directional stability of automobile during braking and braking process of automobile. Braking efficiency-the braking distance or braking deceleration of a car is evaluated by the braking distance from braking to parking at a certain initial speed on a good road surface. The shorter the braking distance, the better the braking performance. The constancy of braking efficiency-the anti-fading performance of the brake refers to the degree to which the braking efficiency of the brake is maintained when the car is continuously braked on a long slope and at a high speed. Directional stability of automobile braking-the performance of automobile braking without deviation, slippage and loss of steering ability. At present, mainstream models are equipped with ABS, ESP and other configurations to improve directional stability. Braking process of automobile-mainly refers to the action time of braking mechanism. Handling stability The handling stability of an automobile refers to the ability that the driver can drive in the direction given by the driver through the steering system without feeling nervous and tired, and when encountering external interference, the automobile can resist interference and maintain stable driving. Vehicle handling stability is usually evaluated by the stable steering characteristics of the vehicle. There are three steering characteristics: understeer, oversteer and neutral steering. When a car with insufficient steering characteristics accelerates around the circle at a fixed steering angle, the turning radius will increase; Under this condition, the turning radius of a car with the characteristics of oversteering will gradually decrease; Cars with neutral steering characteristics have the same turning radius. Easy-to-handle cars should have appropriate understeer characteristics to prevent sudden tail flick. Ride Comfort The ride comfort of a car is the performance of keeping the vibration environment of the passengers comfortable when the car is running. This is closely related to chassis parameters, body geometry parameters, power and handling of the car. Passing capacity refers to the ability of vehicles to pass through certain road conditions. With a powerful car, you can easily climb steep slopes, safely drive into rivers with a certain depth, or drive at high speed on rugged mountain roads, and you don't have to worry about getting on and off the roads in the city. In short, it can make you more likely to go where you want to go than other means of transportation and let you experience the feeling of conquering nature. Edit the automobile performance index in this paragraph. Under certain conditions of use, the ability of an automobile to work at the highest efficiency is called automobile performance. It is a representation of the structural characteristics that determine the efficiency and convenience of automobile use. Capacity: rated loading quality, unit loading quality, unit effective volume of container, unit area of container, number of seats and number of people who can stand. Easy to use: easy to operate, fast to get out of the car, convenient for passengers to get on and off and load and unload goods, reliable and durable, maintainable and pollution-proof. Fuel economy: minimum fuel consumption, average minimum fuel consumption speed performance: power, average technical speed, off-road performance, maneuverability: minimum ground clearance, approach angle, departure angle, front and rear axle load distribution, tire pattern and size, number of drive axles, minimum turning radius, etc. Safety: stability, braking ride comfort: ride comfort, complete equipment. Most traffic accidents are caused by the rear-end collision between the front car and the rear car. When the front car brakes, the rear car gets too close and slows down, causing two or more cars to collide. In order not to hit or be hit by someone, when driving at high speed, always pay attention to the speed of the front car and observe the dynamics of the rear car through the rearview mirror. After driving a certain distance, you should step on the brakes to remind the rear car to pay attention to the distance from the front car. It is very practical to drive at night or brake on the highway to prevent rear-end collision. Traffic jams often occur in cities now. Many roads are parallel to pedestrians, non-motor vehicles and motor vehicles, and there is no isolation pier between the opposite traffic flows, which makes it difficult for novices to drive. Generally speaking, the closer to the intersection, the slower the speed of the vehicle. At this time, pedestrians and non-motor vehicles passing through the road will take advantage of the gap. If you are galloping on the opposite road (there are generally no big obstacles in front of the intersection, so the speed is faster), and you can't tell which car the pedestrians are coming from, it is very prone to traffic accidents. In this case, don't drive too fast, and pay attention to driving at medium and low speeds. Some novices are not familiar with traffic rules and driving routes. When they go the wrong way, they immediately turn around and completely ignore the vehicles on both sides. This is very dangerous. You should first observe whether there is a sign ahead that allows you to turn around. If you have to turn around as a last resort, don't turn around when there is a train waiting on the opposite side, which will cause traffic jams. You have to wait for the opposite car to start slowly and turn around quickly when the distance between cars is widening. Nowadays, many viaducts have been built in big cities, and there is a big gap. Novices often can't control the brakes when they drive off the bridge. If the vehicle brakes are not working, the consequences will be unimaginable. Don't panic at this time, quickly step on the clutch and shift to low gear, and use the braking force of the engine to slow down the car. Some people drive downhill, that is, slide in neutral, and step on the brakes when they see the car in front. This is very dangerous. The safe way is to put on the brakes and slide in neutral until you can see the bottom of the bridge clearly, put the gear lever in low gear, then slow down and slowly drive off the viaduct. Driving skills in snowy days There are two main difficulties in driving in cold winter in the north. One is that the temperature is low and it is difficult to start. Second, the road is slippery, and the direction and brakes are easy to get out of control. When the temperature is around -20℃, the EFI car parked in the open air has not encountered any difficulties, but it is close to -30℃ and often cannot be started, especially when the power is insufficient. 58. Clear the frost and snow before getting on the bus. Before getting on the bus, clear the frost and snow on the front and rear windshield, lampshade and rearview mirror, and clear the snow on the soles of your feet. The key is that the foot brake pedal can't be slippery with ice and snow. Check antifreeze, oil and tires again. 59. In cold weather, start the car with the clutch in neutral, and don't step on the accelerator, and the instantaneous ignition will not hit. Every time the interval is greater than 10 second, it will be played at least three times. The purpose is to start the lubrication system. After the fire, still step on the clutch in neutral and warm the car at idle speed. /kloc-release the clutch after 0/minute. If you can't hold it, just step on it for a while. After the fire, release the clutch and continue to warm the car at idle speed 1-2 minutes. If you are busy for a long time and still can't catch fire, and the battery is dead, don't call again, the battery can't stand it! There are three options: one is to use it to make a fire, the other is to change the battery, and the third is to drag it to the maintenance department. 60. The road of ice and snow begins with hard and slippery ice and snow roads. Put on second gear, step on the accelerator slowly, lift the clutch to linkage, stop for a while, and lift it slightly. If the car moves, keep lifting, refuel slowly and go. If the wheels slip and can't walk, step on the clutch pedal, change the gear to 1, then lift it and step on it again, so that the car can shake back and forth, gradually expanding the range of shaking back and forth. After several times, when I saw Xiangqian Che shaking, I lifted the clutch pedal and left. If you still can't walk, look at the distance behind the car, step back a little and try again. You can always succeed. Finally, if you still can't walk, you have to clean up the ice and snow under the driving wheel, or pad the sand, which is a bit troublesome. 6 1. Stop and start again when the soft snow directly below reaches 10 cm. Also, put on second gear, slowly lift the clutch and start slowly. The point is to let the wheel turn slowly, and never turn too fast. If you follow the usual operation, the wheels will slip and idle, but they will not walk. If the snow slips and you can't walk, take a step back and try again. If you really can't walk, you need someone to push you, or clean up the snow and sand under the driving wheel. 62. When driving at a low speed, control the speed at about 20-30 kilometers on the uncertain smooth road surface, and enter the rutted normal road surface with a speed of up to 40 kilometers per hour. When you see the black road surface after snow removal, you can drive normally, but always pay attention to the snow and ice that may suddenly appear. 63. Slow refueling When driving on smooth ice and snow roads, refueling should be light and slow, which will make the wheels spin and slip, and the direction will be out of control. 64. When driving on the ice and snow road without gaps, it is not allowed to slide in the gaps. Especially when going downhill, you must put a low gear in advance to drive safely. 65. Skillfully slow down and drive on smooth ice and snow roads. When you drop from high speed to low speed, you can't rush to collect oil or step on the foot brake! We can only use the method of gradual downshift to slow down, and use the braking force of low engine to slow down. Only when the speed is very slow can you collect oil, neutral, and brake on your foot. If you don't know the braking method of ice and snow pavement, lift the accelerator and brake with your foot, and the consequences will be unimaginable! 66. Slow steering should also slow down first, then slowly hit the steering wheel and appropriately increase the turning radius. Steering operation should be smooth and soft. When the steering wheel is in a hurry, it is not turning, but slipping and losing direction control. 67. Take the grooved wheel and choose to take the straight groove or rut on the ice and snow road. At least one wheel walks in grooves or ruts to prevent side slip. Never go where there are no ruts and snow. 68. Keep your distance on the icy road. Cars may slip irregularly at any time, so you should try to stay away from other people and cars and take precautions. 69. What can I do to get rid of the state of uncontrolled sliding on the ice and snow road? I didn't step on the brake, but clicked on the accelerator and accelerated by intermittent refueling, so that the driving wheel could find the action point and restore the driving ability, thus restoring the car's ability to control the direction. When driving correctly, the waist is the most laborious, because all the strength of the upper body is in the waist. Therefore, for people who often drive, it is very important to learn to adjust the seat to the best comfort. First, adjust the height of the seat, and adjust the seat up and down so that the head is at least one punch away from the roof. If the seat is adjusted too high, the head will easily hit the roof when the vehicle bumps, and if it is adjusted too short, it will affect the line of sight. Then adjust the distance before and after. When the foot steps on the brake pedal to the deepest point, the leg still needs to have a certain degree of curvature. The backrest should not be too straight, nor should it be half lying down. The best driving state is that when the shoulders naturally lean back, the wrist should just be able to ride on the steering wheel after the arms are straightened, so that when the steering wheel is twisted, the force can be used, and the functions such as the kilometer, speed and fuel quantity of the dashboard can also be displayed within the line of sight. When holding the steering wheel, it is best to put your hands at the "3 o'clock" and "9 o'clock" positions. The thumb naturally rests on the steering wheel spokes. Some drivers like to stick their thumbs in or pull the wheels from the inside when turning. In fact, this is a very dangerous driving habit, which will make the driver unclear about the steering feedback of the steering wheel. In addition, in the case of poor road surface or emergency operation, it may also hurt his fingers. Novices who verify the distance from the following car often can't judge the distance from the preceding car, so they are often far away from the preceding car, which affects the traffic speed and creates conditions for other cars to merge, causing hidden dangers of accidents. There are also some bold novices who are close to the car, but their ability to deal with emergencies is very poor. Once the front car slows down or stops a little faster, it is easy to rear-end. So how to keep a proper distance when following the car? The distance from the car is different under different road conditions and different speed. A general principle is that the front and rear cars must keep a safe distance. That is, when the preceding vehicle slows down or brakes, there is enough safe distance between the two vehicles, so that the driver of the following vehicle has enough time to react and take braking measures. At the same time, keeping a limited following distance can effectively prevent vehicles in other lanes from merging into their own front at will. Beginners had better practice repeatedly in different road conditions. When practicing, choose a multi-lane road in the same direction. When driving, you can refer to the following distance of the vehicle in the next lane and verify it yourself. However, the practice process should be gradual, and the distance with the car should be from large to small until it is reasonable and safe. Hope to adopt the answer, thank you!

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