Chapter 170: Standard Tire Pressure

Song Guoyuan's finger lightly swiped the surface of the tire and said: "If the tire pressure is too high, or too low, it will cause fuel consumption to increase, and it is best to adjust it to the standard tire pressure specified by the manufacturer......

"Will too high or too low tire pressure cause fuel consumption to increase?" Song Guoyuan's words had not yet been finished, and they had already aroused questions from Wang Hu and others.

Everyone has heard of it before, and some 4S stores will even suggest that car owners take the initiative to lower the tire pressure, saying that this will save fuel.

Based on his own experience, Wang Hu asked: "I have heard that the tire pressure should be lowered a little, especially in the summer, because the weather is too hot. ”

Xu Hong hesitated for a moment and expressed his opinion: "I remember that some car owners will even take the initiative to deflate and reduce the tire pressure in order to make their cars look low and good-looking." ”

Liu Liang paid more attention to racing, he heard that some cars filled the tires with nitrogen, and wanted to ask Song Guoyuan if it was any good to do so.

......

Five people, one after another, threw out questions one after another, almost annihilating Song Guoyuan, and this master of the auto repair industry was also a little overwhelmed.

Fang Yuan has a car dealer system, knowing that what the master said is right, he waved his hand and asked everyone not to speak: "Standard tire pressure, since it is called standard tire pressure, it is the correct tire pressure that needs to be maintained by the owner during use, it is obtained by various OEMs according to countless experiments and painstaking tests, and it is not allowed to be adjusted up or down at will, if everyone is so willful, there is no need to formulate a standard tire pressure." ”

Fang Yuan's words were a little heavy, because there was a rush of anger in his heart.

Fang Yuan is not disgusted with Wang Hu and others for having too many problems, not angry with his colleagues, he is very disgusted that the Internet is full of a lot of popular science knowledge that is difficult to distinguish between true and false, which disturbs everyone's cognition.

Take this tire pressure as an example, a casual search on the Internet, there are a lot of contradictory, diametrically opposed arguments, many articles say the same thing, but the result is diametrically opposite, bewitching car owners to do this, do that.

These people are selling methods that have not been demonstrated, that have not been experimented, and what if something goes wrong?

If these people are so good, why do they need so many engineers from the OEM?

Since these people claim to be extremely correct, why do OEMs bother to make standard tire pressures with effort and money?

Fang Yuan was even thinking, since these people are so smart, the main engine factory can not spend billions or billions of funds to develop new cars, find these people, touch the upper lip with the lower lip, and the accurate data will come out, but the first car manufactured will ask them to come for a test drive.

Fang Yuan, who relieved the master, had a somewhat unkind face, coupled with his prestige among his colleagues and his status in the car dealership, the chaotic crowd thought that their leader was angry, and they immediately shut up and did not dare to say anything, and listened to Song Guoyuan honestly continue to speak.

"Don't worry, I'll answer you one by one. At this moment, Song Guoyuan was very patient, and once again pointed to the place where the tire and the ground were in contact, and explained to everyone seriously, "As I said just now, if the tire pressure is too low, the contact area between the tire and the ground will increase......"

Everyone nodded, expressing their recognition of Song Guoyuan's current statement, because the facts are in front of them, the tire pressure of the current Audi A4allroad is low, and as Song Guoyuan said, the contact area between the tire and the ground has become larger.

Song Guoyuan compared the distance from the ground to the edge of the wheel: "If the tire pressure is too low, the friction between the surface of the tire and the ground increases, the carcass material will be crushed and fractured, and the damaged tire can not bear the total load of the vehicle, and the tire life will be shortened and the fuel will be consumed, which will cause damage to the wheel hub and puncture." ”

Song Guoyuan's words were reasonable, and with the physical objects in front of him as on-site teaching tools, everyone was very convinced and gradually realized their mistakes.

"Nitrogen-pumping tires is not so magical, at least it has no effect on tire pressure and tire temperature stability while driving......," Song Guoyuan deliberately emphasized after explaining Liu Liang's problem, the standard tire pressure recommended by various OEMs is not the same, for example, the standard tire pressure recommended by Chevrolet Malibu is 2.4bar, while the standard tire pressure recommended by Harvard H6 is 2.1bar.

And the standard tire pressure refers to the tire pressure when the car is cold, not the tire pressure displayed during the car's driving.

Some OEMs will even mark the tire pressure when light load and full load according to the performance of their own models, at this time choose which one as the standard tire pressure, it depends on whether their car is more when it is light loaded, or more time when it is fully loaded, which situation is more than which one is regarded as the standard tire pressure.

In addition, some models consider that the front half of the front-wheel drive model is heavier, which will cause the front tire to bear more pressure, so it is carefully recommended that the front tire pressure should be a little higher than the rear tire pressure.

Of course, if your car is not marked with front and rear tire pressure, then all the same by default, don't do anything high and low.

As soon as Song Guoyuan's voice landed, Liu Liang continued to ask: "How can I know what the standard tire pressure of my car is?"

Song Guoyuan was old, and after talking for a long time, he seemed a little tired, Fang Yuan was a little worried about his master's body, and preemptively explained to Liu Liang: "Generally, it will be noted on the inside of the fuel tank cap, or check the co-pilot's B-pillar." ”

Liu Liang and the others didn't have a car, and they didn't pay attention to such details, but now that Fang Yuan said this, Liu Liang and the others suddenly understood.

Liu Liang and the others also noticed Song Guoyuan's tired expression, and asked Fang Yuan instead: "What did Master Song say just now about ordinary tires, BMW, and mini?

"Of course. Fang Yuan told Liu Liang that it also depends on what the standard tire pressure is written on the nameplate of the car body or the fuel tank cap.

"Other models have spare tires, BMW and mini are flat-proof tires, and you don't need a spare tire at all. Liu Liang said with envy that he wanted to buy a BMW in the future.

"Brother Liu, it's not right for you to think like this. In Fang Yuan's view, Liu Liang's idea is very dangerous, the run-flat tire is stronger than ordinary tires, and when there is no gas, it can also drive about 80 kilometers at a speed of no more than 80 per hour, which is enough to persist until it finds an auto repair shop, and now many ordinary tires can also do this.

People design this run-flat tire not to let the car continue to drive after a problem, but mainly to prevent the body from losing control in the case of a sudden loss of tire pressure, and to drive the car to the nearest place where it can be inflated and repaired in time.

The shorter the time, the better, and if you work with illness for a long time, tires, wheels, ball joints, swing arms and other parts are also very easy to scrap.

And the run-flat tire is not so strong that it is fearless, BMW's run-flat tire is afraid of the bump of the road teeth and ditches, otherwise it is easy to break down.

"Oh, I see, I thought I could go on a rampage with a run-flat tire. Liu Liang blushed a little embarrassed, and then realized that a run-flat tire is not a panacea.

"BMW and mini don't have spare tires, and now some models are starting to have no spare tires. Fang Yuan remembered a message in the car dealer system and told Liu Liang and others that the first thing some car owners do after buying their cars home is to remove the spare tire fixed in the trunk or on the chassis, because this reduces weight and saves fuel.

This practice of these car owners has inspired some OEMs, although they are not equipped with run-flat tires, but they have prepared some tools to repair tires to replace spare tires.

This approach saves trunk space and saves fuel consumption, but it also has disadvantages, in short, there are pros and cons, and Fang Yuan has not commented much.

......

After finishing the exterior inspection, Song Guoyuan asked Liu Liang to open the hood again and began to inspect the engine, coolant, water tank and other places.

Song Guoyuan inspected these places very quickly, roughly looked at the working condition of the engine, and made sure that there was no shaking and violent abnormal noise, so he turned to other places such as oil circuits, focusing on checking the problem of oil leakage and leakage, which was not as comprehensive as when Sun Yanming identified the car.

"Because most of the car condition appraisal is checked by professionals, the pre-travel inspection is the owner of the car himself, and most of the car owners do not have sufficient auto repair skills, in many cases it is also in vain, so only use to check the shaking, abnormal noise, leakage, etc. can be clearly seen and heard. After Fang Yuan stood next to explain to everyone, Liu Liang and others felt that it was right, they did not have the skills of auto repair, and it was in vain to see it, in case it was bad if it was broken, it was better to just do a preliminary inspection, and if you feel that your heart is not steady, you will go to a professional auto repair shop or 4S shop.

Liu Liang and others now know the difference between car condition identification and temporary detection, this time no longer make a fuss, wait until Sun Yanming sits in the car, check the oil pressure, brake system, steering machine and other places are not faulty, and finally determine that this Audi A4allroad is at the peak of the state, just need to put a little pressure on the line.

Song Guoyuan just did a very simple inspection, and it took nearly an hour to be busy, sweating profusely, Liu Liang and others were envious, and felt that Song Guoyuan was far too good to the other party.

Fang Yuan had a car dealer system, and it only took a few seconds to get the same result that Song Guoyuan took an hour to get, but he was also grateful to Song Guoyuan.

After telling everyone about the simple test, Song Guoyuan began to ignore everyone, and instructed Liu Liang to put the car on the lift, and began to do a more detailed test alone.

The crowd gathered around them dispersed, and they were busy with what they should be busy with.

Liu Liang came to Fang Yuan and said with great envy: "Master Song is so good to you. ”

Fang Yuan smiled, he had heard Sun Yanming say that his master had a very strange temper before, but after such a long period of contact, he learned that it was not the case at all.

Song Guoyuan's face is cold and warm-hearted, especially paying attention to professional ethics, and refusing to do things that violate professional ethics, which makes Fang Yuan very respectful in this regard.