Car operation in winter: 16 myths and facts. Can you tell them apart?

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Veröffentlicht am Übersetzt mit Hilfe von KI aus unserem Originalartikel (Quelle:

Driving in winter can have its charm, but it can also bring in many worries and problems. And we do not mean just the icy and snowy road, but especially the low temperatures that our cars dislike.

How to deal with low temperatures? Many myths are out there on the internet, and the advice tends to be half-true. Let's take a look at both of them.


1. You must wear winter tires in winter = Myth

This statement is not true. In some countries, you cannot enter the road with summer tires at a specific time of the year. Others take a different approach, and you can have summer tires as long as there is an absence of a continuous layer of snow, ice, or frost on the road. Summer tires are only effective when the temperature is higher than 7°C.

It is more reasonable to replace summer tires with winter ones if you live in a colder climate in winter time. In addition to the fact that driving in winter with summer tires is dangerous, you risk a fine and problems with the insurance company in the event of an accident.

2. The more additives I pour into diesel, the better = Myth

This statement is not true. Excessive addition of additives to diesel can cause oversaturation with additives, which deteriorates their properties and negates their function. This can occur especially if you add additives to premium diesel, which already contains additives.

3. Long engine start-up makes no sense = True

If the engine does not start within the first 10 to 15 seconds when starting, there is no point in trying to start it any longer. In this case, the starter heats up significantly and can be damaged. In addition, the battery starter takes a lot of energy, which is needed by the glow plugs.

It is ideal to wait at least 30 seconds after a failed start, give enough time for the heaters to generate enough heat, and try to start again. However, if you do not manage to start the engine even after several attempts, you should start looking for the cause somewhere else, for example, by checking the fuel filter. Otherwise, you will only achieve a total discharge of the car battery.

4. If I start the engine before removing the frost from the windows, I will have them cleaned sooner = Myth

You can clear the ice from the windows before the engine warms up and starts heating. In addition, warming up the engine on site is prohibited in some countries, as it is harmful to the environment and ineffective. During quiet driving, the engine warms up much faster.

5. The engine consumes more in winter = True but only partially

At low temperatures, injecting more fuel into the engine (enriching the mixture) is necessary. Otherwise, starting a cold engine would not be possible. However, as the engine temperature rises, the enrichment of the mixture decreases, and thus the fuel consumption also decreases.

In addition, at low temperatures, the viscosity of the engine oil also increases, which causes higher resistance for the moving parts of the engine, which also increases fuel consumption. Other factors that increase fuel consumption in the winter are, for example, snow or ice on the road, winter tires, and constant heating of the windows, steering wheel, and seats.

It must be remembered that when the engine reaches its operating temperature, it has the same current consumption as in the summer. Driving style, a longer time for the engine to warm up, snow on the road, and other factors mentioned above are behind the higher consumption, but not the effect of winter on a warmed-up engine.

The engine must maintain its constant working temperature regardless of the outside temperature.

6. A frozen lock can be opened with a hot key = True

Usually, you only need to heat the key slightly, and you can open the lock without any problems. However, you cannot overheat the key, because some parts in the lock mechanism can be damaged due to large temperature fluctuations.

7. Riding in ski clothing is prohibited = Myth

Driving in ski or thick winter clothing is not prohibited but dangerous. Rough winter clothing limits the driver's freedom of movement and the ability to react quickly, which is a decisive factor in crises.

In addition, if the clothing is too thick, the seat belts do not surround the body as they should and thus cannot sufficiently protect the passenger in an accident.

8. At low temperatures, the battery has less power = True

The performance and capacity of the accumulator decrease significantly with the decreasing temperature. Even at temperatures slightly below zero, the classic accumulator can only have half the capacity as in warm weather.

However, starting problems may not be caused only by lower battery performance, but also by longer parking of the car, because the battery self-discharges faster at low temperatures. So it's worth carrying jump-start cables with you in the car.

9. Before starting at low temperatures, turning off the radio will help = True

At very low temperatures, the battery needs almost all its capacity to start the engine. It is, therefore, better to turn off the radio, heating, and all devices that could draw energy from the battery before starting.

10. If I turn on the heater immediately after starting, the engine warms up later = True

Switching on the heating too early extends the engine's warm-up time. A cold engine consumes a significantly larger amount of fuel than a warm engine.

In addition to higher consumption, moving components' wear increases due to greater resistance and insufficient lubrication, due to the higher density of engine oil at low temperatures. That is why it is recommended to turn on the heating only after approx 5 to 10 minutes after starting the engine.

11. Diesel at low-temperature forms flakes = True

Paraffin crystals form in diesel at temperatures below -20°C, which clog the fuel filter. The resistance of diesel to frost thus expresses its filterability. Winter diesel, sold at our pumps, must withstand temperatures of at least -20°C, and premium diesel can also withstand temperatures below -30°C.

However, low-quality diesel can also contain water, which freezes much earlier, so it is necessary, especially in winter, to refuel with high-quality diesel from certified sellers. Otherwise, it may happen that you won't start your car until the temperatures rise, or until you tow the vehicle to a garage or other warm place.

12. If I don't start, I can easily crush the car = Myth

Pushing the car and releasing the clutch with gear two or three engaged is not recommended. This is not because you could not start the vehicle using this method; on the contrary, there is a risk of breaking or skipping the timing belt/chain and colliding with pistons and valves.

Such a repair would be costly, and if you have an older car, it could even exceed the price of the entire vehicle. So I really wouldn't recommend pushing the car. However, the exception can be crises when starting the vehicle.

13. Heating the fuel filter and battery helps to start easier = True

If the paraffin crystals clog the fuel filter, you can deal with this problem very easily by heating the fuel filter, which will cause the accumulated paraffin to break up and restore the diesel flow. You can heat the fuel filter, for example, with hot water or a hair dryer.

As for the battery, you can also help it in the cold before starting. If you have left your car in the cold for several days and are unsure whether the battery will have enough energy to start the vehicle, heat it, and its capacity can increase by 30-40%.

Before starting, you can remove the battery and submerge it up to the top edge in warm water so that it shines, or you can put a bag of warm water on top of the battery, or open the hood and let the sun warm the battery.

14. I can unfreeze the window with hot water = Myth

Hot water can cause a dangerous voltage on cold glass, which could lead to its breaking. A safe way to defrost glass quickly is to use a dedicated defrosting agent.

15. I can start the car even if the coolant freezes = Myth

If the coolant freezes, do not start the engine under any circumstances. The solidified cooling mixture could damage the water pump and other cooling system parts. It is, therefore, essential to check the freezing point of the coolant before winter.

If the freezing point of the coolant in your engine is at least -25°C, such a problem should not occur in our conditions, so you have nothing to worry about.

16. In winter, it is better to have a full tank = True

The most common cause of clogging of the fuel filter is water in the diesel or, as I mentioned in point 11 - clogging of the filter with paraffin crystals. The prevention against water in the tank is always refueling with a full tank, or at least 3/4 of the tank.

The tank will have a minimum of air humidity, which would otherwise condense into water. You can also help a diesel car in the winter by refueling with a small amount of gasoline. Gasoline can dissolve paraffin crystals in the tank, which clogs the fuel filter.

It should be remembered that adding gasoline to diesel reduces its lubricating ability, which can damage the fuel system. That is why you should be careful when pouring gasoline into diesel fuel and mix it at a maximum ratio of 1:15, i.e., 3 liters of gasoline per 45 liters of diesel fuel.

However, you can avoid all these problems if you have not neglected the preparation of your car for the winter and have sufficiently prepared for it.