10W-40: transcript. What do the numbers "10W-40" mean in engine oil?

For all the time of existence of the automotive industry has not yet invented a better way to protect the engine than engine oil. And although its structure has been constantly updated over more than a century of history, the principle of operation remains the same - ensuring the proper coefficient of sliding between the elements of the engine with cooling of the surface. One of the most commonly used species is oil 10W-40. The interpretation of this designation gives complete information about the characteristics of the liquid.

Application area

For a better understanding of the rules of application and the choice of engine oil, you need to know more about the principle of its effect on engine parts.

During the operation of the power unit, friction between its elements inevitably occurs. In particular, this applies to the movement of pistons in the heads of the cylinders and crank-and-rod mechanisms. This produces high temperatures that adversely affect the material and can lead to rapid wear.

Motor oil is a kind of liquid gasket between them. As soon as the engine starts and the first batch of fuel burns - oil under the influence of moving parts is evenly distributed over the surface. This is an exaggerated characteristic, since a complete description in the details of the whole process in most cases is only necessary for specialists. For the consumer it is important to know not only what the 10W-40 means, but also the main parameters:

• Composition.
• Temperature limitations.
• Viscosity.

According to the engine parameters and external factors, the choice of the most suitable oil is 10W-40. Decoding will give full information about these characteristics.

Composition

Ideas for the application of motor oil were laid even at the stage of designing the first internal combustion engines. Before the development of the chemical industry, only one of its species was known - mineral. The composition includes natural components, which are obtained as a result of oil refining. But its properties do not always correspond to the external conditions and characteristics of the engine. Disadvantages of mineral oil are:

1. The change in the coefficient of viscosity when reaching the limiting temperatures (both minus and plus).
2. Relatively low shelf-life. The longer the oil is in the engine, the more its internal structure changes. This leads to a loss of positive properties.

Undoubted advantage can be considered affordable value.

In the second half of the twentieth century a new kind of oil appeared - synthetic. It came from the aviation industry. Obtained as a result of a complex synthesis, the tool quickly became popular.

A special design for launching aircraft engines at low temperatures has found its application in the automotive industry. Therefore, engine oil 10W-40 has the following advantages:

1. Large temperature range of operation.
2. Long service life without loss of properties.
3. Unique viscosity parameters, which are peculiar only to this kind of engine oil.

In order to make cheaper manufacturers, an intermediate variant was developed - semisynthetic types. This is the result of mixing the above types of lubricants.

Explanation

Now that the main species are known, a detailed description of the oil characteristics of the 10W-40 can be started. The interpretation of this notation consists of several indicators.

• 10W means maintaining the viscosity parameter at a minimum temperature of -25 ° C.
• 40 - upper high temperature limit (up to + 40 ° С).

In fact, when the manufacturer indicates such data on the packaging, he informs the consumer of the operational limitations of a particular type of oil. How does this actually show up in the operation of the power plant in the event that the recommended temperature conditions do not match the required one?

Non-observance of operating conditions

Reducing the temperature below the limit level leads to an increase in density. In this case, there may be problems with starting the engine - the oil will not be evenly distributed over the surfaces. In this case, rapid wear or breakdown of the power unit is possible. Therefore it is extremely important to know what information this decoding of the oil contains - 10W-40.

As the temperature rises, the oil density decreases critically. It is no longer able to perform its functions, since the viscosity coefficient does not make it possible to create a uniform film. Most of the lubricating fluid settles in the crankcase. With a constantly high temperature regime, a partial evaporation of the liquid takes place. A characteristic feature of this phenomenon is the darkening of exhaust gases and an increase in their volume. This also leads to quick breakdowns.

Classification

It is necessary to select the brand of oil, depending on the field of application. Currently, they use the international standard API - American Petroleum Institute. According to him, a separate classification for gasoline and diesel engines was adopted. The main difference lies in the years of production of models of cars.

Therefore, to select a lubricant it is not enough to know what the numbers on oil 10W-40 mean. In addition to these data, it is necessary to take into account the classification. For modern vehicles, the markings shown in the table are accepted.

Sometimes there are brands that can be used for all types of power units regardless of the type of energy carrier.

Quality parameters

After choosing the type of oil, as close to real operating conditions, you need to make sure of its quality. To do this, you can use two different methods:

• Experimental. Through long trials and mistakes to find a really high-quality oil 10W-40.
• Read more about the API classification.

The latter method is more acceptable, since it does not pose a potential threat to engine operation. Annually, API representations evaluate new brands of lubricants. Depending on the results, they are assigned a certain quality index.

For gasoline there are eight designations - A, B, C, D, E, F, G, N. For diesel, there are six - A, B, C, D, E, F4. Therefore, when buying, you need to pay attention to the letter - the further it is from the beginning of the alphabet, the better the quality.

Additives

Special chemical components are used to improve the properties of the lubricating fluid. They have received the general name of additives. Therefore, sometimes it is not enough to know the basic properties of the 10W-40. The decoding of the full characteristics of the manufacturer is indicated on the package, including the type of additive, its technical parameters and content.

There are many different types of additives. Some of them are added directly by the manufacturer, some are sold separately for independent use.

The most popular at the moment are the following types:

• Increasing viscosity index.
• Removing combustion products from the internal surface of the engine.
• Increasing durability.
• Prevent the development of oxidative processes.

Before adding each of them, you should carefully read the instructions for use. After all, in addition to the positive effect, there may be side effects.

Advice

To ensure that the engine has fulfilled the put resource and in order to avoid unforeseen breakdowns it is recommended to follow the following tips for choosing the oil:

1. Before buying it is necessary to consult the recommendations of the car manufacturer.
2. It is mandatory to make a replacement oil according to the schedule of the manufacturer. For urban conditions, when driving at low gears, the consumption of lubricant increases. It is best to undergo periodic testing in a specialized service station.
3. Before pouring any engine oil 10W-40, it is necessary to flush the engine. This will increase energy resources and eliminate the possibility of a decrease in performance.

Experienced motorists are always guided by these rules - it's enough just to make a schedule for a technical inspection of the machine.

Having learned the specificity of the name of motor oils, you can safely choose the type of lubricant you need. Given the large number of manufacturers, this can be quite difficult. For every car enthusiast, it's important to know what 10W-40 means. Therefore, it is necessary to take a responsible attitude to this issue - the cost of repairing a car is incommensurably greater than the price of a good oil.