Is it really wrong to leave without heating the car?

There is indeed a lot of entanglement about whether to warm the car after the water temperature drops after the vehicle has been parked for a period of time. The old driver's habit is to warm up the car for a long time. He often starts the car first, then walks around the car, checks the condition of the car, and then gets on the car and drives away. However, new drivers are generally at a loss and don't know what effect or influence hot cars have on vehicles.

Why do you want to warm the car? Because the engine does not work after the vehicle stops and stands still, the engine oil will all sink to the bottom, resulting in no engine oil in the upper part of the engine. If you start the vehicle directly, it may cause engine wear. This is the first reason to warm up the car, but now the engine manufacturing technology is more and more advanced, and it takes only a short time for oil to be re-lubricated to all parts of the engine, about ten or twenty seconds.

Another reason is that when the vehicle is driving, it needs to vaporize gasoline through temperature to work normally. However, the newly started vehicle does not have the temperature of completely vaporizing gasoline, which will lead to insufficient combustion of gasoline during use and easy to form carbon deposit.

From the above analysis, we can know that it is best to have a warm-up process after parking for a period of time, but this process does not take long, about half a minute in summer and 1 minute in winter. You can see that the tachometer has dropped, so you can use low-speed driving instead of in-situ preheating. When the engine water temperature reaches above 60 degrees, it can basically run normally.

Proper hot start is beneficial to maintain the state of the vehicle, but it is not a good thing if the hot start time is too long and the idle speed is too high. It will also cause insufficient combustion of gasoline and excessive carbon deposition, which should also remind car owners.

This question is hard to say, because it depends on your starting point. I think we can look at these points:

1, which is right in terms of environmental protection.

I remember that Volkswagen's manual mentioned that the engine should be started immediately after starting, otherwise it would increase the emission of pollutants. In Chinese, it means heating the car in situ, which wastes the oil that could have been used to drive the car forward. When you finish heating the car, it will cost more oil. This increases the emission of pollutants.

2. From the driving experience, it is good to warm up the car properly.

If you tell car owners in the north, especially in Xinjiang, Inner Mongolia and Northeast China, you can't warm your car in the same place, they will probably kill you. If the temperature is low in winter and the car is not warmed properly, it will be uncomfortable to drive, and the engine will warm up for a long time, and the idle speed will remain high. The automatic gearbox does not upgrade against the cold, the manual gearbox is stiff and astringent, and there are ten thousand kinds of unhappiness. Therefore, it really won't be too hard for them to leave in winter.

3. For the health of the engine.

Although there is no exact data, I feel that the engine oil will reach the parts that need lubrication soon after the cold start of the engine, and I think this time should not exceed 10 second. Therefore, it should not be a problem to supply oil after the cold car starts. Theoretically, idling a hot car for a long time will increase carbon deposition, but I think this amount is very small. When the engine temperature is normal, increase the speed and let the intake air wash, which should not accumulate too much. So idling in place, I don't think it hurts the car that much. You can ask those drivers who drive for the leaders full time. In summer, as long as the leader goes out, the car will hardly stall. Otherwise, the leader will be angry if the car is too hot after getting on the bus. Just ask them if the car they drive has serious carbon deposition.

I think you can go after the idle speed is stable under normal circumstances, usually more than ten seconds, except in winter. If it's really urgent, it's no problem to hit and leave. If you are afraid of the cold when you go out in winter, you can also warm the car in situ. It doesn't matter if the warm wind comes. Just wait until the temperature comes up and then pull up the highway.

Strictly speaking, hot cars are necessary, but they should be suitable. It is not good to leave after ignition, because the oil is still in the crankcase, and there is no metal original inside the engine, in other words, there is no oil film. In this state, especially in winter, the engine is very easy to wear.

Therefore, it is very necessary to preheat the car properly. My method is to start the car and preheat it for 30-45 seconds, so that the oil completely wraps the metal parts in the engine and forms an oil film. Actually, 30 seconds is enough. Then drive in D gear, keep the engine speed around 1500 rpm instead of 2000 rpm, and then drive for a certain distance in this way. When the temperature rises, you can drive normally.

Speaking of hot cars in the same place, it takes at least five minutes for the temperature to rise in winter. Instead of producing so much carbon deposits in the same place for five minutes, it is better to drive a distance lightly. The temperature is still fast and won't hurt the car, but remember not to exceed 2000 rpm.

Yes, there is nothing wrong with it. You know, in Germany, it is illegal to warm the car in the original place! According to German law, in-situ hot car is equivalent to discharging pollutants. Once found, a fine is required. Have you subverted your cognition?

On the one hand, this law in Germany is related to the global control of pollutant emissions, on the other hand, rigorous Germans believe that modern cars that have passed the carburetor era no longer need in-situ heating.

Let me talk about the harm of hot cars in situ first. When the engine is idling in place, the air flow into the engine is very small. At this time, the engine temperature is not high enough, and the combustion needs air and temperature, both of which are not up to standard. Incomplete combustion will occur and carbon monoxide will be produced. When it is heavy, it becomes carbon particles, that is, carbon deposits, which attach to the surfaces of valves and cylinders. With the accumulation of carbon deposit, it will seriously affect the performance and emission of the engine. Idling in place for 3 minutes is equivalent to the fuel consumption of driving 1 km. While wasting fuel, it also emits more polluted exhaust gas, which is not good for you (wasting time), cars (producing carbon deposits) or the earth (emitting pollutants).

As for why there is always a hot car? Let's start with the carburetor. The carburetor needs a certain temperature to work normally. According to the physical principle, the cylinder generates negative pressure, and the gasoline is sucked out of the carburetor by narrowing the intake pipe. Let gasoline and air mix and atomize freely and enter the engine cylinder for combustion. The reason why the old driver said that the car was hot in place was because the carburetor was not easy to use at low temperature, and the gasoline sucked out kept this water droplet state, which directly affected the normal work of the engine. If the road on the bus is not hot, if you refuel at any time, you will not go, and the brakes will turn off, which will seriously affect the driving safety. Therefore, vehicles using carburetors must be preheated in place before they can get on the road safely.

Fortunately, the carburetor was eliminated as early as 200 1. Instead, it is an electronically controlled gasoline injection system. It precisely controls the injection of gasoline to ensure good atomization. Even at low temperature, the atomization efficiency will not be affected, and small droplets of gasoline will not appear again, so there will be no danger of unstable speed and flameout. However, hot car in situ not only brings carbon deposition but also pollutes the environment, so there is no reason for us to hot car in situ.

However, I'm not telling you not to heat the car. What we need is a low-speed hot car.

Today, when automobiles are highly electrified, every automobile that leaves the factory is equipped with electronically controlled fuel injection or a more advanced gasoline in-cylinder direct injection system. These systems all need to control the fuel injection state through the fuel injection applet.

Moreover, we are worried that the car will be injured if it is not hot in winter, mainly because the engine oil is not lubricated enough for the main parts of the engine at low temperature.

However, at the moment of automobile ignition, the time for the oil pump to push the oil into the oil pipeline is less than110 second. Let the oil form a circulation loop between the oil pipe and the oil pan. Through the heat energy generated by engine operation, the temperature of these oils rises rapidly, and with the increase of temperature, the lubricating effect of the oils will get better and better.

Here I have to talk about the standard for everyone to measure whether the car is hot enough-the water temperature.

Water temperature actually refers to the temperature of antifreeze. The engine is covered with oil pipes and antifreeze channels. When the car is cold, the antifreeze flows back to the lower half of the water tank, and when the car is ignited, the water pump works at the same time, so that the antifreeze instantly forms a waterway circulation in the engine waterway. Take away the heat of the engine, in the water tank at the front end of the engine, after radiating through the wavy micro metal pipe, it flows back to the engine waterway and continues to take away the next wave of heat. When the water temperature is constant at 90 degrees, it shows that the working temperature of the engine has stabilized and reached the best working state. Just when the water temperature is constant at 90 degrees, don't wait in the same place, choose a low-speed hot car.

What is a low-speed hot car? After we light the fire in the morning, fasten your seat belt, pay attention to the surrounding car conditions, and then we can start! ! ! The whole process is 15 second at most.

Yes, it is so refreshing. However, please note that if you want to make the car durable, don't exceed 2000 rpm at low speed. Driving at low speed for 2-3 minutes can make the oil reach the normal working temperature. As for why low speed is needed? Because the friction between metals is fierce, and the lubricating effect of oil at low temperature is not very good. Don't let the metal rub too hard, after all, it takes time for the oil to reach normal temperature. 2-3 minutes is enough.

What are the advantages of this low-speed hot car?

First of all, save your precious time. I have already driven 1 km compared with the hot train that took 3-5 minutes.

Second, while stepping on the accelerator, although the engine is still in a low temperature state, the throttle opening becomes larger, the air flow into the engine becomes larger, and the incomplete combustion of gasoline is greatly reduced, which means that the generation of carbon monoxide and engine carbon deposit is greatly reduced, and the car naturally becomes more durable and environmentally friendly.

In fact, there is another saying that hot cars are used to preheat the gearbox. That's right, the gear shift is rough when the car is cold, because the gearbox oil flows to the lower half of the gearbox in the cold state, and the gearbox gear is not fully lubricated. But the car is not allowed to move, and the engine is not engaged with the gearbox. It has not been running, and it is still in a low temperature state. How to lubricate gears when they don't run? How can it have a preheating effect?

For in-situ hot cars, Germany has banned them. We don't need to make stupid mistakes again. Just remember to heat the car at low speed.

First, let me talk about what I did. After I got on the bus, the oil warning light went out. I fastened my seat belt and checked the car condition and road conditions. At this time, if the engine runs smoothly, I will start driving at 50 km/h in third gear.

In extremely cold areas, below MINUS 20 degrees, if the oil and gearbox oil are not properly configured, you should step on the clutch until the engine runs smoothly, and slowly lift the clutch to drive the gearbox to run. When the engine and gearbox run smoothly, start driving, and the speed of the third gear is within 50 km/h.

In any case, driving safety in cold areas in winter is the first priority.

Interested friends, you can continue to look down, if you have no time to look here.

When winter comes, people have different views on hot cars. See how the national automobile inspection agency does it!

Let's talk about the misunderstanding of friends who support the idea of hot car in situ.

These friends think that cold car driving increases engine load, surface stress of parts and wear. In fact, after the cold car starts, as long as the oil pressure warning light goes out, it means that the oil has been sent to the friction surface. What we need to do at this time is to warm up the engine as soon as possible, and don't accelerate quickly.

If the car warms up in the same place and the engine runs at no load, the temperature of the coolant will rise slowly, and it will take a long time for the engine to reach the normal temperature. Therefore, during preheating, two disadvantages will occur:

1, long running time at low temperature and increased wear;

2. The atomization of gasoline is poor at low temperature, so it is necessary to inject more fuel to maintain combustion. Ungasified fuel washes the cylinder surface, destroying the formation of oil film and accelerating the wear of parts;

3. Increased pollutant emissions;

4. It is easier to form carbon deposits.

Everyone should understand that driving at a low speed is to warm up the engine as soon as possible.

Every car in the automobile factory must pass the national emission standards. The fifth stage document is GB 18352.5-20 13 emission limits and measurement methods for light vehicles (China Phase V), (GB18352.5-2018332).

There is a test period of minus 7 degrees in this standard. The vehicle is required to be stored at minus 7 degrees 12 hours but not more than 36 hours, and then tested. About the standard drawing, I turned it out from the standard document.

After the cold car starts, take four small cycles, each cycle 195 seconds, ***780 seconds. Driving a small cycle is also to simulate the driving process of our actual car. The graph and table of the small loop are as follows.

Each small loop has three parts.

1. Idle after landing 1 1 s, and then return to idle in the first gear of 15 km/h;

2. Idle at 2 1 s, then rise to the second gear of 32km/h, and then return to idle;

3. Idle at 2 1 sec, rise to the third gear of 50km/h, and gradually return to idle;

Look at the watch. Here is just an example, the driving method for measuring automobile emission level formulated by the state. After landing 1 1 second, that is, the time to fasten your seat belt, check the car condition and check the road conditions after landing, you can start.

Now the car really doesn't need to be preheated in place, just ignite it directly. However, it should be noted that the cold start oil does not adequately lubricate the engine gearbox and other parts, so do not drive violently.

A more reasonable way is to check around the car after ignition, and then fasten your seat belt and leave. The automobile has developed for a hundred years, and the engine technology is relatively mature, so it will not be as fragile as we thought. Therefore, as long as it is properly maintained, there is no problem with safe driving. There's really no need to worry about the hot car for a minute or two.

Hot cars are a bad habit left by old drivers in China when they started to drive tankers, so that they are now misled into thinking that they will drive away hot cars in winter.

What car needs a hot car to go?

Twenty years ago, most cars were still using carburetor engines. Carburetors are mechanical devices that atomize gasoline. At extremely low temperature, the gasoline concentration is high, atomization is difficult and combustion is insufficient. You have to buy fire fighting and black smoke, so you have to start in winter, and you have to warm up the car before you can drive. But this habit can be completely abandoned in the era of EFI cars.

Do you need a hot car now?

From the working principle, any mechanical device needs preheating, but in the carburetor era, it needs manual preheating. In the era of EFI, the on-board computer will help you coordinate the preheating of all components, and you only need to drive forward step by step. At this time, you will find that the idle speed of the engine is relatively high and the speed is relatively slow, which is actually the result of the automatic warming-up of the car.

Now the most important thing for cars to predict is the oil temperature. When the oil temperature rises, it can lubricate and protect the engine. If the oil temperature is low and viscous, the engine protection is not enough. But you don't have to wait in the same place for this job, just drive straight ahead.

Harm of in-situ hot car

The biggest harm of in-situ hot car is to produce a lot of pollutants. Due to the idle hot car in situ, the engine speed is low and the air intake is insufficient, which leads to insufficient combustion and a large number of pollutants are removed. In addition, due to insufficient combustion, it will also cause carbon deposition in the engine.

None of the operating instructions of this car clearly States that it needs to be warmed up after the ignition is started! Then why do we have the concept of hot car? That's because we know the engine too well, and we all know that the best state of engine operation is after the water temperature and oil temperature rise! It is the best operation mode of the engine, so we have the concept of hot car, thinking that hot car will be good for the operation of the engine!

That's right, that's right. After we start the hot car, it will be of great help or protection to the engine operation! (Generally, we only need to wait for 30 seconds to warm up the car), but I want to tell you that we left as soon as we set off. This situation has little effect on engine wear. These can basically be completely ignored! Because the design and manufacture of an engine has long considered this problem! If the engine is damaged just because the car is not hot, it is a big joke!

In fact, hot car is to achieve an ideal engine oil temperature and water temperature. There is nothing wrong with this concept! To correctly understand how to do it, wait for 15-30 seconds to start the train. In fact, it is entirely possible! In fact, it is completely possible to start the car directly without heating. It turns out that when the starter of the engine is ignited for the first time, the whole oil circuit of the engine has already started running! So don't worry at all! The engine of the car is not as fragile as everyone thinks!

Many novices are used to starting the engine directly when driving, but is this correct? Is hot car a necessary preparation before driving? Is the car not hot harmful to the engine? Let's discuss it together today.

The concept of hot car originated more than 20 years ago. Most of the engines used at first are low-speed engines. In winter, in order to ensure the lubrication of the engine and transmission system of the vehicle, it is often necessary to slowly fill the accelerator so that the vehicle can be fully heated before going on the road.

But in fact, with the development of economy, technology is also updating and iterating. Looking at the current cars, most of them use high-speed engines and short connecting rod transmission systems. As soon as the engine starts, the oil is sent to all corners, and the slowest is only three or four seconds. Cold car ignition will not hurt the machine, so there is no need to warm the car now, which means it is not a necessary step before starting.

Now, when the car is hot, the engine needs to idle in place. At this time, the air flow into the engine is very small. At this time, the engine temperature is not high enough, and the combustion needs air and temperature, both of which are not up to standard. Incomplete combustion will occur and carbon monoxide will be produced. When it is heavy, it becomes carbon particles, that is, carbon deposits, which attach to the surfaces of valves and cylinders. With the accumulation of carbon deposit, it will seriously affect the performance and emission of the engine.

Therefore, in general, the current engine does not need to be warmed up in advance, but it does not mean that it does not need to be warmed up. Everyone can warm up at low speed on the road, which can not only ensure sufficient engine power, but also reduce the possibility of carbon deposition. Therefore, while loving a car, we should also care for the environment and truly save energy, low carbon and travel in an environmentally friendly way.

As a maintenance technician who has worked for many years, I personally think that you are really wrong! There is a simple reason.

As a car owner, everyone knows that there are necessary oils such as engine oil, antifreeze and gearbox oil in the car to maintain the normal operation of the engine and gearbox. Among them, engine oil and gearbox oil mainly play the role of lubrication, and antifreeze mainly plays the role of cooling. When our vehicle is left for a period of time, the temperature of the engine and gearbox will drop to the same temperature as the outside air, which is often much lower than when the vehicle is driving normally. If the temperature when the vehicle is running normally is set to normal temperature, the temperature after being left for a long time is called cold car temperature, and starting the engine at this time is called cold start!

Why can't I drive immediately after a cold start? According to my years of maintenance experience, there are two main reasons!

First of all, after being left for a long time, engine oil and gearbox oil will flow back to the oil pan of the engine and gearbox along the oil path of the engine and gearbox due to the influence of gravity. Therefore, under normal circumstances, when the engine and gearbox are cold started, all parts that need lubrication are short of engine oil and gearbox oil; After the cold start, the oil pump inside the engine and gearbox starts pumping oil into the oil circuit, which takes some time! Especially at the moment of start-up, although the oil pump has started running, the amount of oil pumped out at the initial stage of operation can not fully meet the lubrication needs of the engine and gearbox! If you turn on the throttle immediately, it will increase the load on the engine and gearbox. Due to insufficient lubrication, the engine and gearbox will be worn to a certain extent, and its service life will be greatly reduced if it is used for a long time! This is also the reason why many cars will make an obvious sound of about 5 seconds at the moment of starting after driving for a long time. This is caused by insufficient lubrication during cold start and oil shortage of hydraulic tappet of engine internal valve!

Secondly, many car owners will find that after each cold start, the engine speed will be maintained at 1500 rpm for a period of time, and then it will gradually drop to about 750 rpm. This is because the theoretical air-fuel ratio of the engine is now designed as 14.7: 1, which means that theoretically burning one kilogram of fuel requires 14.7 kilograms of air. The better the air quality, the more fuel is needed! During cold start, the quality of cold air around the engine is much larger than that during normal warm start. In order to achieve the theoretical air-fuel ratio and make the tail gas produced by combustion cleaner, the fuel injection can only be increased accordingly, that is to say, the engine speed should also be relatively increased! However, at this time, the oxygen sensor for detecting engine exhaust emissions is still in open-loop control because of its low temperature, so it can't detect the concentration of exhaust emissions in time and participate in the fuel correction of the engine, which will lead to the concentration of exhaust emissions when the car is cold! At this time, it will not only cost more oil, but also make the engine burn insufficiently, producing a lot of carbon deposit and waste tail gas! These carbon deposits continue to accumulate and attach to engine valves, pistons and three-way catalysts for a long time. Slight consequences are engine jitter, fire and weak acceleration, and serious cylinder pulling, engine oil burning and even scrapping!

To sum up, leaving the ignition is really harmful to the engine! Personally, I suggest that the majority of car owners stop after starting the car 15 to 30 seconds, so that the engine and gearbox can have enough lubrication time before starting driving, which can effectively protect the engine and gearbox, prolong the service life and reduce carbon deposition!