Marking of motor oils. Expertise: “killing” imported synthetic oils with Russian gasoline Choosing the right products

One of the main characteristics of motor oil, which motorists use when choosing the appropriate composition, is the viscosity parameters. In this case, the lubricant manufacturer does not play a big role; it is more important to select a high-quality composition suitable for a specific engine model, following the recommendations of the car manufacturer. The most popular among consumers are all-season synthetic or semi synthetic oils with SAE index 5w30, 5w40, corresponding to the temperate climate of central Russia.

Today, with a huge number of brands, it is difficult to determine which product is the best; each of the leading manufacturers of auto chemicals demonstrates excellent quality indicators in one category or another. It will not be possible to find an undisputed winner in all categories. Manufacturers of lubricants often cooperate with well-known automakers, and many of the formulations are developed specifically for a specific car model. Thus, the most ideal option for one engine will not show the desired results when used in another unit.

Ratings are compiled based on the popularity of the product, taking into account consumer demand and reviews, based on the results of laboratory research, as well as tests on special stands with motors famous companies. Today, every reputable automotive publication conducts its own tests, identifying winners in different categories. Popular compositions with SAE 5w30 parameters have been repeatedly tested by specialists using various testing methods. Tests were carried out both in normal and in the most severe operating modes on stands and cars. Most objective assessment Only an independent examination can give, determining the best motor oils with a viscosity of 5w30 based on the results of the study.

Key features of 5w30 oils

Motor oil has a direct impact on engine performance. When choosing a lubricant, it is better to follow the car manufacturer’s recommendations specified in the manual, because existing approvals indicate that the product meets the manufacturer’s requirements, and before giving the lubricant its approvals, the automotive giants test it.

All motor oils can be divided into three main types:

• synthetic;
• semi-synthetic;
• mineral.

Synthetics have undoubted superiority, therefore the best motor oil with index 5w30 is made on the basis of components produced by synthesis with a package of additives that give the composition additional characteristics. Semi-synthetic is alternative option use and often demonstrates quite impressive results in operation, but it is still not as durable as synthetic lubricants. Mineral compounds are used extremely rarely, mainly on old cars, and do not have high performance. Such oils are completely inapplicable in the SAE 5w30 viscosity class, since they freeze at sub-zero temperatures.

Lubricants are produced for diesel or gasoline units. There are also universal formulations used in different types engines. The main parameter characterizing the properties of the product is its viscosity. The SAE marking indicates the temperature range in which motor oil is capable of operating, providing engine parts with reliable protection against wear, as well as performing other functions assigned to the product.

All-season mixtures have the characteristics of summer and winter compositions, therefore they are indicated by an index with two numbers indicating the maximum permissible low and high temperatures. The letter W indicates the possibility of using the product in winter. Decoding the viscosity index 5w30, we get the following information:

• to find out the permissible temperature with a minus sign, we subtract the number 35 from the first digit of the index, therefore, the liquid can be used when the readings on the thermometer are not lower than -30 ° C;
• the maximum positive temperature for using the product is determined by subtracting 5 from the second digit of the index, which means the oil can work at +25° C.

The products under consideration with viscosity parameters 5w30 do not lose their properties in the temperature range from -30° C to +25° C. The use of compositions with these characteristics in case of deviations from these standards will significantly reduce engine life. Many motor oils are positioned as products with an extended replacement interval, called Long Life, but in fact, under completely non-ideal operating conditions, the replacement period can be extended to 30,000 km. mileage is something out of science fiction.

The rhythm of life in big cities implies the inevitable presence of traffic jams, stops and a lot of gas pollution. Engines are forced to idle a lot, which increases wear on the mechanisms. Rough countryside and off-road conditions also have a negative impact on oil life. For this reason, the lubricant replacement intervals recommended by the car manufacturer do not always coincide with reality. Another important factor affecting the performance of the lubricant is the quality of the fuel used. The results of numerous checks have confirmed that low-quality fuels significantly reduce the service life of oils.

To maintain the service life of the unit, 5w30 engine mixtures must perform their functions under different load conditions. The standards of a modern lubricant with these viscosity parameters and a set of additives assume that the products have the following qualities:

• improving unit performance;
• good envelopment of engine elements, creation of a durable protective film, due to which friction of parts is reduced;
• , corrosion prevention;
• heat removal from rubbing elements;
• removing traces of wear from the friction zone;
• cleaning mechanisms from combustion products and other deposits.

Before a lubricant formulation is assigned a parameter, a test determines its compliance with existing standards. Based on expert assessment during testing, the 5w30 motor oil rating is formed.

Test conditions

A full-fledged study of motor mixtures is a rather lengthy process; it combines laboratory examination and practical testing. Oils are subjected to chemical analysis and a series of tests are carried out so that the product can receive specifications and be marked with certain tolerances. You can find this information on lubricant cans and check whether the characteristics of the products are suitable for the motor for which the product will be used. Testing in laboratory conditions is not allowed full picture, as during tests using benches, the real durability of the oil can only be determined relatively, because in practice the engine can be subjected to serious loads and the influence of numerous unfavorable factors.

In order to more objectively rank synthetic motor oils 5w30, products of the same category were used, and their characteristics were carefully studied during the research process. Despite the differences in composition, the results revealed compliance with the available tolerances and standards for this group of lubricants. The sets of additives for all competitors were also different, but the features of each product did not prevent us from leveling the odds based on the results of the chemical and physical study. Next, the tested formulations, which had similar parameters and claimed to be the best 5w30 motor oil, were tested under the same conditions. The test was carried out over a period of 10,000 km. mileage (standard replacement interval), 55 hours of the race the engines were idling, 100 hours of operation at average speeds of 6000 per minute, which included 45 cold starts of the unit, as well as loads created by traffic jams.

During the tests, all motor oils behaved differently; when evaluating each of the parameters, some showed themselves better, others worse, but still later evened the scores. During the experiment, lubricant had to be added to the engines. When compiling the rating automobile oils It is impossible to determine 100% which of the competing products is the best. The thing is that the most suitable option for one engine will not give the same efficiency for another, and when choosing a composition for your car, you should definitely follow the manufacturer’s recommendations specified in the manual.

Distribution of brands based on testing results

Each rating is relative, as automakers, independent automotive publications and other organizations interested in oil testing nominate different brands of oils and conduct their own test for the best 5w30 synthetic motor oil. Expert assessment is not always objective and often there is a different view, supported by weighty arguments. In this case, the top 5w30 motor oils look like this:

The composition is used for gasoline and diesel engines; it maintains the cleanliness of parts throughout its service life thanks to the unique Intelligent Molecules, but after 10,000 km. the oil needs to be changed; at the end of the tests, there were residual parts wear in the waste fluid. low waste consumption, complies with the assigned standards.

The engine oil is suitable for all types of engines, has energy-saving properties and can be used on new Ford units. The composition provides reliable protection throughout the operational period, but the cleaning characteristics were not up to par, so it is not recommended to postpone replacing the lubricant.

Hydrocracked oil for new passenger vehicle engines. The manufacturer assures that it will provide reliable protection under severe operating conditions and long runs. The product performed well during testing, but has a higher waste consumption and a higher share of iron in waste than its competitors, so it is necessary to increase replacement intervals to more than 10,000 km. still not worth it.

Economical synthetic with high detergent and anti-wear properties for any type of engine. During testing, the product demonstrated average performance in all respects, is characterized by stable operation, and complies with the available tolerances.

A premium quality product with good cleaning, protective and anti-wear properties, it works on any engines under different load conditions. According to the results of the race, it showed a minimum of waste, a small content of wear products in the waste liquid. The engine oil meets the declared characteristics.

A synthetic energy-saving product with Ford recommendations is used for gasoline engines passenger cars. with low waste consumption and minimal signs of wear. Considering the cost of the product, this is an excellent option that meets the specifications stated by the manufacturer.

Designed for motor operation under different operating modes, it is economical. Tests did not reveal resistance to high loads, interval of 10,000 km. The oil cannot withstand harsh driving conditions.

The lubricant composition is recommended for all types of engines, reduces fuel consumption, and provides protection to unit parts. In other tests, XQ LS 5W40 with the same characteristics performed much better than the 5W-30 viscosity product. Engine oil is characterized by low waste consumption, but during testing many signs of wear were found.

The products in question were distributed in the top in different positions, but this does not mean that any mixture is worse than the previous one, located one line higher. All formulations passed the tests and met the specifications indicated on the packaging, but still did not show miraculous properties. Before you fill your car’s engine with a lubricant flavored with loud statements from its manufacturer, check the car manufacturer’s recommendations and change the engine oil in a timely manner, without relying on a long-lasting lubricant life.

The most popular of all the presented fuels and lubricants is 5w30 synthetic motor oil from the world's leading brands.

The main and main task of lubricants is to protect engine parts from running dry and to ensure normal work under conditions of complete sealing of the working cylinders. Properly selected motor oil is the key to proper engine operation and increases the service life of its components.

The fuel and lubricants market is represented by three product categories:

• for cars with gasoline engines;
• for diesel units;
• universal, which have physical characteristics that allow them to be used in engines internal combustion and diesel engines.

According to seasonality of use, lubricating fluids are distinguished:

• winter – 5w, 10w
• summer,
• all-season – 0w 30, 5w30

Regardless of the category of lubricant product, motor oil has the main parameter physical properties, determining its effectiveness. This is the viscosity (5w30), that is, the ability lubricant maintain fluidity while remaining on the surface of the parts. The protection of parts from friction and wear during vehicle operation depends on this indicator. If the viscosity (5w) does not correspond to the recommended one, then the engine life is reduced. Also great importance has a second indicator (30) - this is high-temperature viscosity. Its deviations from the recommended may cause the engine to major renovation faster than originally planned. Since in this case the engine operates at higher speeds, which can take it out of the range of maximum permissible standards.

When choosing a lubricant, you need to take into account the viscosity index. It should not exceed the parameters recommended by the manufacturer. Otherwise, you will increase the load on the engine, which can lead to serious damage and subsequent expensive repairs.

How to make the right choice?

What should you pay attention to when choosing universal fuels and lubricants for your car?

1. Viscosity index.

• The ability to start the engine in winter conditions depends on it. The lower this indicator, the easier the engine obeys the ignition signal.
• The degree of coverage of engine parts with lubricant in order to prevent friction and wear, as well as to prevent chemical and mechanical damage, depends on the viscosity.

1. Temperature regime.

• It determines the minimum threshold for the effectiveness of using a given type of lubricant in the cold season.
• It also sets the temperature range at which the use of oil fluid guarantees safe operation of the vehicle when the engine heats up.

This classification of fuels and lubricants based on viscosity and temperature conditions was established by the American community of engineers SAE. The compliance of motor oils with this classification is indicated on each package “sae”.

Series 5w 30

The most popular of all the presented fuels and lubricants is synthetic motor oil of the 5w30 series. The characteristics of the products of this group meet the stringent requirements for vehicle operation in cities and on highways. City mode is different:

• prolonged idling of the engine,
• car idling in traffic jams,
• stable trips over short distances,
• increased dust content in the airspace.

These factors significantly reduce the service life of engines. A correctly selected oil product is the key to long-term operation and technically sound condition of the engine.

Automotive lubricants of the sae 5w30 class are distinguished by a unique formula based on the synthesis of an oil base and a package of additives that are characteristic of synthetics, providing:

• protection of the engine from friction and wear of parts,
• resistance to oxidative processes during operation in conditions of high humidity and climatic precipitation.

The additive package may vary. They all perform only their specific functions. It is a balanced set of additives that makes the oil base suitable for use in any particular type of engine. In each specific type of lubricating fluid, the compliance of additives must be within the framework of the standards for the quality of motor oils.

It should be noted that changes in the heating temperature of the motor can change the properties of lubricating components. Depending on the intensity of its work, motor oils of the sae 5w30 class can heat up to 150 °C. When choosing engine oil, you must rely on specifications recommended by the vehicle manufacturer. Oil approval is not given for a specific car brand, but directly according to the engine type. Therefore, the brand of oil fluids can be any, but the main parameters of the lubricant must meet the requirements set by the manufacturer of your car.

Buying synthetic or mineral motor oil with sae 5w30 is a purely personal matter. This depends on the age of the car, engine characteristics and operating conditions. Some are inclined to believe that cars older than 5 - 7 years accept mineral lubricants better, as this reduces oil consumption and increases engine life. In this case, it is better to opt for increased viscosity.

For cars with new generation and foreign-made engines, synthetic motor fluids are recommended for use. From this series, synthetic motor oils of the sae 5w30 class are in greatest demand, as they satisfy climatic conditions and traffic intensity in urban format.

Replacing lubricant

The frequency of replacing lubricant in a car depends on operating conditions, mileage, and the condition of engine parts. The best option is 10 thousand km. In difficult conditions of use, this period can be reduced to 7 - 8 thousand km. mileage With a dual fuel format, for example “gasoline - gas”, the replacement period increases to 15 - 20 thousand km. This is due to the fact that gas fuel is a more environmentally friendly product and is gentler on the parts of the unit. It is necessary to monitor the quality of engine oil in the engine and its quantity once every two weeks. For this purpose, cars have a special dipstick indicating the minimum and maximum oil level.

Classification and standards

Synthetic motor oils sae 5w30 meet environmental requirements. All representatives of this group not only have SAE, ACEA and API compliance, but are also certified for use in vehicles with valve petrol and diesel engines from major manufacturers such as BMW, VOLVO, RENAULT, MAN. To obtain approval from manufacturers, all oil products undergo strict control and numerous tests. All declared characteristics must comply with the manufacturers' requirements.

SAE - classification of lubricant products by viscosity (5w);

ACEA is a European classification based on the set of additives and the quality of the final product.

API is an American classification of fuels and lubricants by engine type. Separates the purpose of the oil for use in gasoline (SJ) and diesel (CF) engines. The absence of this information indicates an outdated quality class.

Advantages of choosing 5w30 synthetics

Thanks to technical staff 5w30 synthetics have the following advantages:

• enhanced protection of internal engine parts from mechanical and chemical influences;
• provide heavy-duty film coating of engine parts from the inside;
• protective properties against oxidation and corrosion;
• protective functions in relation to the moving parts of the motor from mechanical friction and wear during operation;
• greater time range between engine oil change procedures;
• The universal lubricant composition 5w30 allows the use of fluids of this class in different types of power units.

Synthetic sae 5w 30 is a demi-season lubricant, which allows it to be used all year round. There is no need to change the oil according to seasonal changes. At the same time, it does not lose its properties and remains effective for any engines.

Synthetics 5w 30 CF series for diesel engines

Synthetic low ash motor oil 5w 30 is designed for diesel cars and supplied dual system exhaust gas cleaning. This category corresponds state standards environmental friendliness of lubricating fluids. Recommended for vehicles with particulate filters, turbocharging and catalysts. Complies with the latest API SN/CF, ACEA C3 requirements.

In the production of 5w 30 diesel motor oils, modern basic components are used, developed using new nanotechnologies. They increase protective functions and reduce the amount of waste emissions. Synthetic additives have a reduced content of sulfur, phosphorus and chlorine bonds.

5w30 motor oils have characteristics recommended for filling in diesel engines With particulate filters and turbines:

• keep the working unit clean;
• provide quick access to engine parts;
• maintain normal operating pressure in the engine at any load level;
• guarantee durable lubrication at low and high temperatures;
• reduce fuel consumption;
• reduce the amount of exhaust gases.

Diesel engine oils sae 5w 30 guarantee high vehicle performance and increase service life gas neutralizers. Car manufacturers allow the use of synthetic sae 5w 30 with the specified properties, which maintains preferential conditions for vehicle maintenance during the warranty period.

Modern lubricants have the ability to reduce fuel consumption. Being a universal lubricant, motor oils are used both in new generation cars and in older models of global automakers. One of the significant indicators in choosing a lubricant is its compliance with all necessary regulations and standards.

Every motorist knows that from the right choice engine oil depends on the service life of the engine. Owners modern cars you need to think less about which substance is better to choose, because current manufacturers recommend products for specific characteristics different engines. It is more difficult for users of older vehicles to make a choice. To prevent the unit from presenting unpleasant surprises, for example, in winter, they need to be very responsible and attentive to the designations of the oils presented on the canisters. But the symbolism is so diverse, how to make the right choice?

Main settings

If you decide without professional help choosing motor oil means you need to familiarize yourself with the car manufacturer’s recommendations, taking into account the main differences between current lubricant products. An example would be semi-synthetic 5w40 and all-season oil 5w30. What is the difference between the presented products, which oil is better for your car model?

The main parameter of the oil is viscosity. According to the SAE (American Association of Automotive Engineers) classification, a double number in the classification, for example, 40, indicates the versatility of the product. It can be used at any time of the year.

Let's look at the notation using 5w40 as an example. In this case, the first value 5W describes the viscosity at low temperature. Semi-synthetics thicken more when the temperature drops. Consequently, it is more difficult for the pump to pump liquid. The second number indicates the high temperature of the liquid. The high viscosity of 5w40 promotes the formation of a durable film that provides good protection for the rubbing parts of the power plant. As for the numerical values, all liquids under consideration differ only in the temperature viscosity index.

Similarity of goods

Semi-synthetic ultra 5w40 is a high-quality product that provides good lubrication to all moving engine elements. The acceptable viscosity of the product allows you to start the engine even at low temperatures in winter. In hot weather, Shell 40 oil provides protection due to the formation of a good lubricating film.

Motor oil 5w30 is semi-synthetic with application class 5w. The product is distinguished by providing a durable film and offers good characteristics work. Even taking into account that viscosity significantly affects the functioning of the engine, which is why you need to choose oil taking into account the manufacturer’s recommendations, this product is suitable for most modern vehicles. The letter “W” in the product name indicates that the oils can be used in cold weather.

Comparison of parameters

Whether it is synthetic or semi-synthetic, any product consists of base oils as well as thickening additives. The latter elements are responsible for the necessary characteristics in winter and summer. Lately, consumers are increasingly paying attention to all-season products, because they are much more effective and convenient. The viscosity class directly depends on the amount of additives. 5w40 oil, like 5w30, is capable of changing this characteristic by changing the shear rate. Accordingly, the lower it is, the higher the viscosity of Shell 40 oil. For example, the semi-synthetic index 5W30 varies from 9.3 to 12.6 mm2/s. For 40 the range is smaller - from 12.6 to 16.3 mm2/s.

When comparing 5w30 and 40 oils, it should be noted that they have different amounts of thickening additives. Therefore, determining which engine oil is best to use should be based on the viscosity characteristics, manufacturer’s recommendations, and weather conditions. In our case, when high temperatures the indicator is 30 and 40. The parameters determine how long the protective film will last on the parts of the unit in the summer. This is an important characteristic of semi-synthetics, because the film is responsible for premature wear of power plants. If you use the wrong fluid, it is quite likely that the engine will stop unexpectedly during hot weather.

Considering that the higher the viscosity, the higher the resistance the pump will work towards lower flow. Consequently, the user will allow premature wear of the power plant as a whole. Due to oil starvation, parts will begin to fail and the engine will gradually break down. Accordingly, if 5w40 is recommended, but the engine is filled with semi-synthetic 30, then the oil film will not be strong enough and the oil will be too thin. Thus, in tribosystems (a system of units subject to friction), premature wear of component parts will also occur.

The difference between 5w40 motor fluid and other oils is that 40 is an average value. This product copes with the tasks set by the manufacturer, both in winter and in summer, excellently. The characteristics of semi-synthetics with index 30 are more likely to be designed for modern car brands. The difference between the above products and oils with an index of 50 and above is a wider range of applications. In the latter case, it is recommended to use the product for cars with high mileage.

In general, the differences between motor fluids 5w40 and 5w30 are not significant, however, if the engine temperature is 100-120 degrees, it is better to use 40. The viscosity will be one and a half to two times higher. For this reason, 5w40 series motor oil can be used even for internal combustion engines that have a high thermal load. Semi-synthetics are attractive due to the preservation of their original properties while high voltages. Even at high speed shifts and high temperatures, the lubricant will create a durable film to protect spare parts.

Speaking about which oil is better to use under heavy loads on the engine, the answer is obvious - semi-synthetic with an index of 40! But when choosing between the described options for winter, you should consider 30. Perhaps it would be more rational to use this type due to the fact that it starts the power plant more efficiently when it’s cold, because it has less viscosity. At high loads, the liquid becomes too fluid.

Thus, we looked at the nuances of different oils. There is only one conclusion: you should take into account the manufacturer’s recommendations when choosing between different oils and consider the conditions under which the product will be used!

It is impossible to imagine the operation of any rubbing parts without lubrication, the task of which is to reduce wear of mating surfaces and remove heat from the friction zone. Internal combustion engine installed on most modern cars, like no other mechanism, is sensitive to the characteristics of the lubricants used for its normal functioning. This is due to high rotation speeds of parts and microscopic gaps between parts. Plus, power plants are forced to operate in a wide range of temperatures, which, as is known, have a significant impact on the properties of materials, including lubricants.

International classification systems provide for the gradation of motor oils according to a number of indicators. The most important among them is the viscosity indicator, regulated by the SAE specification. Currently, some of the most popular oils are those with the designations 5w-30 and 5w-40 defined by this standard. We have already familiarized ourselves in detail with the methods by which the viscosity-temperature properties of lubricants are established. The information provided in that article will be needed to compare the characteristics of the oils in question.

Motor oils 5w30 and 5w40: difference in viscosity-temperature properties

So, the marking of 5w-30 and 5w-40 oils begins with the same index 5w, which indicates low-temperature viscosity, which affects the cold start of the engine and its operation at subzero temperatures. This parameter will not be of interest to us, since it is the same in both cases, which means there are no differences in this part. But the second number is different for the compared oils. It determines high-temperature properties, characterized by two indicators - kinematic viscosity at 100 °C and dynamic viscosity at 150 °C. If we compare the values ​​of these parameters for 5w30 and 5w40 oils, we will find that in the second case it will be greater, i.e. 5w-40 oil is more viscous. In practice, this means that the lubricant has a thicker consistency and, accordingly, less fluidity. In what cases will this be beneficial for the engine, and in what cases will it harm it? We'll figure out.

As is known, the gaps between friction pairs in an engine (for example, crankshaft-liners or piston-cylinder) are measured in thousandths of a millimeter (microns). The exact values ​​are determined by the developers power unit. The gaps formed must be filled with a lubricant so as to exclude the possibility of dry friction on some areas of the contacting surfaces. Which oil can do this optimally is known only to the engine manufacturer, who, as a rule, subjects the assembled power units to a lengthy series of tests. Recommendations for the use of lubricants can be found in the vehicle's owner's manual. It is these, and no other, data that the car owner must operate when choosing a specific brand of oil.

What could be the risk of using motor oils that do not meet the requirements? Here everything will depend on whether the oil poured into the engine has a higher or lower viscosity than the recommended one. If oil with a higher high-temperature viscosity is used, then at some engine operating modes the thickness of the film formed between the rubbing parts may not correspond to the required values. In the worst case, certain areas may not receive lubricant at all for a short period of time. This is fraught with an increase in engine temperature and accelerated wear of parts. On the contrary, using an oil with a lower viscosity does not pose such a threat, since it is more fluid and will therefore quickly fill gaps. If we look at our case, then if there are manufacturer recommendations, it is impossible to use exclusively 5w30 oil and fill in 5w40 oil. Reverse castling can be done, but it is not advisable, otherwise 5w-30 would also be on the list of permitted ones.

Features of seasonal use of 5w30 and 5w40 oils

There is a situation where the manufacturer allows the use of any of the two types of motor oils under consideration, often stipulating that 5w-40 is preferable to use in conditions of high ambient temperatures. What are these recommendations based on? We have already noted that the designation 5w, which characterizes low-temperature viscosity, is responsible for winter operation. Since it is the same for both types of oils, there will be no differences in engine operation at low temperatures. But when the engine gets very hot, certain features occur.

For most car enthusiasts it is no secret that normal working temperature engine temperature is 86 °C, and deviations from this value are minimal. The readings are taken from a sensor built into the cooling circuit of the power unit, i.e. Engine temperature is nothing more than the temperature of the coolant. It would seem that the oil should not heat up any more. However, in fact, the temperature of engine oil under certain conditions can reach 150 ° C, and one of the factors influencing the maximum value is the outside air temperature. Thus, driving in hot weather at low speeds (standing in a traffic jam) definitely contributes to more intense heating of the engine oil than, for example, driving at average speed in cool weather. This is due to less active air flow around the power plant, which promotes cooling. It is no coincidence that the SAE specification for high-temperature characteristics indicates viscosity values ​​at 100 and 150 °C. So a thick 5w-40 oil at higher temperatures environment in a warm engine it acquires a more liquid consistency than in that situation if it were colder “overboard”. This allows it to form a film of the required thickness, which is taken into account by the manufacturer, who allows the possibility of using this type of oil.

Use of 5w-30 and 5w-40 oils depending on engine condition

During long-term operation When the vehicle is running, engine parts inevitably wear out, causing the gaps between them to increase. Accordingly, the thickness of the oil “layer” required for friction pairs also becomes larger. Up to a certain point, an increase in clearances does not affect the functioning of the power unit, but sooner or later the wear of parts becomes excessive, significantly exceeding the tolerances established by the manufacturer. In this situation, liquid oil, designed for completely different gaps, is not able to form a high-quality protective film in the interface area of ​​the rubbing surfaces, which accelerates their degradation. Another problem could be more oil getting into the combustion chamber and escaping from there. increased consumption. This is exactly the case when filling the engine with 5w-40 oil instead of 5w-30 is a justified step. Its thicker consistency will ensure normal lubrication, but it will not allow it to leak so easily through the increased gaps of the cylinder-piston group or gas distribution mechanism. It is not without reason that after a certain mileage, many car dealers advise switching to oils with increased high-temperature viscosity.

Perhaps this is all we wanted to talk about in this article. We hope that the information presented will be useful in terms of a clearer understanding of the difference between the properties of 5w-30 and 5w-40 motor oils, which influence the choice of one option or another in a particular situation.

When operating a car, owners are faced with the need to replace worn-out spare parts and consumables, including technical fluids.

Regular Maintenance implies a mandatory change of engine oil. Unlike the brand of gasoline, lubricants have many parameters, characteristics and standards.

They can be conditional (tolerances for specific car brands) or unconditional, which determine compatibility with many brands and models of engines.

The most popular is the 5W30 standard, the decoding of which determines the climatic operating conditions. After mandatory connection to the dealer service (end of the warranty period), the driver has to figure out on his own what the labeling of motor oils includes.

Deciphering automobile oils in the light of world standards

Let’s leave out the specific specifications of automakers, although their presence frees us from the need to study other technical characteristics. Any motor oil has universal characteristics that are suitable for different engines.

What do the numbers 5w40 on the canister mean - video

One of the main characteristics is the SAE viscosity classification.

Brief history of the standard

The abbreviation SAE means a formalized society of automotive engineers, which involves almost all states that are in one way or another connected with the production and mass operation of vehicles.

It was founded in 1905, when it became clear to everyone that the future transport transportation for cars. Today, there are more than two and a half thousand standards for the operation of all types of transport and stationary mechanisms.

To understand them for an untrained operator - real problem. After all, these standards are valid not only for the personal vehicle we are used to.

Technologies cover public transport, cargo vehicles, construction and road equipment, agricultural units.

What is SAE in detail - video

The formats, developed by the automotive engineering community and adopted by SAE, create almost 500 working groups accredited in different countries.

In technical forms you can find another name: “J-Reports”. The working groups employ more than 4 thousand certified specialists who have the right to assign international decoding of lubricant designations.

The relevance of the standards has clear objectives that help not only consumers, but also buyers of lubricants:

• setting guaranteed and consistent expectations when using the purchased product;
• compliance with the standards established by international treaties at the expert level;
• compliance with the quality level of produced lubricants;
• guaranteed compatibility of consumables with the units in which they are intended to be used;
• saving Money for the consumer;
• reducing costs for the development and production of new products;
• preservation natural resources, including reducing harm when disposing of lubricants.

Positive results of the activities of the Society of Automotive Engineers:

Popular designations: decoding of 5w30 and 5w40 oils

This classification was adopted by the aforementioned Society of Engineers (SAE) in 1911, when the relative diversity of engines forced oil manufacturers to expand their range.

In addition, by this time, cars began to be used in different climatic zones: it became necessary to classify their applicability depending on the ambient temperature.

It was the viscosity of the oil, or rather the preservation of this parameter in a certain temperature range, that formed the basis of the standard. The SAE classifier received code J300, and included the following temperature thresholds:

• 6 classes for use in winter conditions (in the classical sense for mid-latitudes): 0W, 5W, 10W, 15W, 20W, 25W;
• 5 classes for use in summer conditions: 20, 30, 40, 50, 60.

Since operating cars in tropical climates is not relevant for domestic consumers, let’s consider the so-called all-season oils. They can be poured into a car without being tied to a specific time of year.

At the same time, the designation of temperature compatibility can shift in the desired direction: for regions with a predominance of winter or summer periods.

Narrowly focused standards are typical only for a few regions: the far north, or hot desert areas with constant above-zero temperatures.

note

The Latin letter “W” means Winter, that is, winter. Its presence in the standard means all-season use. That is, the interpretation of 5W 40 prescribes the use of oil not only in winter, but also in summer.

Numerical designations relate the lubricant to temperature conditions, but do not indicate a specific value in degrees. The number to the left of the letter “W” characterizes the winter temperature range, and to the right – the summer one. The connection to temperatures is shown in the illustration, in the form of a diagram.

Two characteristics are especially important for engine operation:

1. Pumpability temperature (minimum and maximum). The numbers mean that within the specified range, the oil is guaranteed to pass through the oil pipeline channels, not harden, and will not flow down.
2. The minimum temperature at which the starter is able to crank the crankshaft to start the engine. Low temperatures They increase the viscosity of the oil so much that it tightly grips the rotating elements.

A good example in the illustration:

In short, for example, the 5w40 oil marking means that the oil is thicker than 5w30 and, therefore, better protects the engine in hot climates.

Mineral water, synthetic or semi-synthetic, diesel or gasoline

Despite the practice of introducing a large number of additives into motor oils, the quality of the final product is 70% determined by the base, that is, the environment into which these components are added.

The SAE classifier requires the following markings:

1. If the oil is produced from a base obtained from the refining of crude oil, the word “Mineral” will appear on the label. It means that the raw materials are 100% of natural origin, and the processing method is distillation.
2. The base stock obtained by synthesis (from natural gas or otherwise) is labeled "Fully Synthetic". At the same time, mineral additives may be present in the final product; this does not in any way affect the origin of the base.
3. In order to reduce the cost of the product, while maintaining the qualities inherent in synthetic oils, manufacturers can mix a mineral base with a base obtained artificially. Such lubricants are designated as “Semi Synthetic”.
4. There is a category that does not fall under any of the above. This is a basic base obtained from natural petroleum by processing using hydrocracking technology.

The procedure is so deep that the properties of the base differ little from pure synthetics. However, it is a mineral base.

With the active lobby of oil producers, the SAE association decided to classify such oils as synthetic. The manufacturer, on a voluntary basis, can label the product with the abbreviation “HC”, that is, hydrocracking. Or maybe not mark it: this is not a violation.

note

Hydrocracking has become so widespread in recent years that more than 50% of oils are created on this base basis.

Diesel or gasoline engines work under different conditions, in terms of oil applicability. For example, engines running on heavy fuel are characterized by shock loads and the presence of soot deposits in the crankcase.

Therefore, there are oils designed both for individual categories(diesel/gasoline) and universal. Information must be included in the labeling.

API classification of oils

Except purely technical parameters, the international community has introduced a quality standard for lubricants: API. Its decoding (for example: API SM/CF) is tied to the engine type, year of manufacture of the car, operational and quality characteristics of the oil.

• the letter “S” indicates that it belongs to gasoline engines;
• The letter “C” indicates that it belongs to diesel engines.

The last letter (deciphering SM, SN, CF, etc.) just characterizes the quality and compatibility with generations of cars.

The higher it is (the serial number of the letter in the Latin alphabet), the higher the quality standard the oil meets. Each subsequent decryption standard absorbs the previous one: that is, there is no backward compatibility.