What are engine oils for? Types of engine oils. as an example, consider the effect of temperature on the properties of mineral and synthetic oils

Most motorists who care about the technical condition of their vehicles are concerned about motor oils, their types and characteristics. The correct operation of the car engine and the duration of its operation directly depend on the quality indicators and performance characteristics. In the article we will talk about the main classification of the product and present a summary table of compatibility of brands and oils.

Requirements for engine oils

The main purpose of oils is to provide effective lubrication of internal elements of rotary and reciprocating internal combustion engines. The product contains base oils and additives that help cool parts that interact with each other during operation.

When motor lubricant is found in the elements of the combustion engine system and on the surfaces of parts, it is exposed to influences of a different nature, namely: mechanical, thermal and chemical. The factor affects the characteristics, which is reflected in the duration of the operating period.

When choosing a lubricant for a motor, it is important to ensure full compliance with three characteristics: the design of the unit, its operating conditions and the properties of the lubricant itself.

Before purchasing, make sure that the oil meets the parameters below:

• Possesses in relation to insoluble inclusions high detergent, solubilizing and dispersant-stabilizing characteristics... The feature helps to effectively clean parts from dirt.
• Differs in high thermal and thermal oxidative capacity to effectively use the engine lubricant to cool very hot pistons and piston rings.
• Possesses the ability to effectively protect engine parts from wear, neutralizing the action of acids.
• Does not have a corrosive effect on metal parts of the motor during operation and during long periods of inactivity.
• Provides engine cold start, effective pumpability of the grease in it, as well as reliable lubrication of parts in extreme conditions.
• Compatible with the material of production of the sealing elements of the systems to neutralize exhaust gases.
• Does not create foam in cold and hot conditions.
• Features low consumption for waste and low volatility.

engine oil

Classification

Since the beginning of the last century, they began to be divided into several categories, depending on the degree of viscosity of the lubricant. A similar classification system, developed and implemented by the specialists of the American Society of Automotive Engineers (SAE), was immediately appreciated by the manufacturers of motor lubricants and their consumers, for whom it became much easier to select them for their equipment.

Such a division is actively used in order to select engine oils, their brands and characteristics, depending on the requirements of the consumer.

When choosing an engine oil, the main selection criterion is its characteristics, which directly affect the durability of the engine and its reliability. An incorrect decision leads to the failure of the entire lubrication system. By carefully studying different motor oils, their brand and characteristics, you can make the most balanced and deliberate choice. The selected product will allow the motor to be operated for at least the manufacturer's recommended period.

Reducing friction is a key function of engine fluid, and engine performance often depends on its quality. If the friction is too high, the engine spends its energy mainly on overcoming this force, therefore, fuel consumption increases, power decreases, exhaust gases become more toxic, and the car is noisier.

Decrease in efficiency is not the only problem, as the metal elements of the motor accumulate surface fatigue, the bonds between the molecules become weaker, due to which even a slight load can lead to the destruction of parts.

Over time, the metal of the engine can completely collapse, since the fatigue limit sooner or later becomes critical.

The surfaces of the engine also suffer from excess friction. The gap between the friction pairs of the motor increases due to their grinding. Shock loads increase in direct proportion to the increase in clearances. As a result, the surface of the parts wears out. At minimum gaps, the noise level is also insignificant, but with their increase, the noise turns into knocking.

It is the use of high-quality oil that avoids the listed problems, but in addition to quality, it is also necessary to take into account the compliance of the oil with the recommendations of the manufacturer of your car.

Timely replacement

Timely replacement of engine oil is a prerequisite for manufacturers, in which the operating life of the engine will be as long as possible. If you ignore this recommendation, you should prepare for the following consequences:

• intensive wear of engine parts, therefore, the failure of the entire unit;
• failure of the oil receiver;
• the engine oil lines are clogged and the engine elements stick together;
• the formation of a solid sediment from the decomposing base;
• filters are clogged with wear products of obsolete oil.

Before deciding which engine oil is the best, you need to make sure that the option you choose meets three characteristics: the properties of the lubricant, the operating conditions and the design of the unit. Also, the oil must meet the following parameters.

1. High detergent, dispersant-stabilizing and solubilizing characteristics in relation to insoluble inclusions. Thanks to this property, it will be easier for you to clean the parts from dirt.
2. The ability to neutralize the action of acids, thereby preventing wear and tear on engine parts.
3. High thermo-oxidative and thermal capacity will allow the oil to be used to cool piston rings and pistons, which are very hot.
4. Low volatility and low waste consumption.
5. Lack of ability to form foam when hot and cold.
6. Compatibility with the material of the seals used in the exhaust gas aftertreatment system.
7. The ability to reliably lubricate parts in extreme conditions, as well as efficiently pump lubricant in the motor and start it in a cold state.
8. Lack of the ability to react with metal elements of the motor during prolonged downtime or during operation.

Specific requirements of car factories

In addition to the basic requirements for engine oil fluids, there are those that are imposed by the car plant itself. We are talking about a list of specific characteristics and their importance can be considered on the following principle.

The range of oils for an old low-performance engine with a carburetor and cast iron liners is much wider when compared to a high-speed engine with a Nikasil block, increased operating temperature and a three-way catalyst. The information in the service book will allow you to deal with the situation and choose an oil that will not damage the engine.

For example, the tolerance of Volkswagen oil - VW 504.00, therefore, when choosing analogues, it is necessary to focus on the same tolerance, since it specifies specific requirements specifically for VW engines that meet Euro 4 environmental standards. Choosing a product with a more recent approval is not always considered justified. In diesel engines of the same Volkswagen, greases with VW 502.00 approval cannot be used.

Lubricants with VW 503.00 approval, in turn, are prohibited for use in engines where there are no indications regarding a newer or specific conformity, since their feature is a reduced high-temperature viscosity.

Engine oil properties

Before considering the various classifications of motor oils and their characteristics, it is worth familiarizing yourself with the properties of motor fluids that underlie these classifications. Among the key properties, the following are worth highlighting.

1. Viscosity- the main property due to which the ability to use the product in engines of different types is determined.
2. Coking- the ability of the oil to form tar and carbon deposits. The better the oil is refined, the lower its coking properties. The optimal indicator is 0.7% for liquids with a high level of viscosity and 0.1-0.15% for low-viscosity substances.
3. Ash content- the presence of minerals that remain after cleaning and can turn into ash as a result of oil combustion. The optimum ash content is below 1%.
4. Content of impurities of mechanical origin which clog filters, oil channels and accelerate engine wear.
5. Water content leads to the formation of foam, which results in poor engine lubrication as the ducts become clogged.
6. Alkaline number determines the amount of alkalis and water-soluble acids in the product, which affects the detergency and corrosive properties.
7. Detergent properties are represented by the ability to prevent the formation of warm varnish deposits on the side surface of the piston and the skirt.
8. Flash point determines the amount of low-boiling fractions in the product, which indicates the ability to form carbon deposits and burn when in contact with hot elements of the engine. The flash point of a good oil should be high.
9. Pour point allows you to determine the moment when the oil loses its mobility and properties characteristic of liquids.
10. Transparency and color determined the quality of the oil earlier. The reference was a clear amber or honey colored oil. Now this indicator is not considered decisive, since manufacturers use different additive packages that can affect the color of the final product.

Individual code

To make the choice of the oil liquid as fast and simple as possible, it is worth familiarizing yourself with the principle of decoding the individual cipher that each product in this category has.

The code contains the following information:

• base (synthetics, organic or semi-synthetics);
• quality and purpose according to API classification;
• viscosity indicators according to the SAE classification;
• production date and batch number.

With the batch number, production date and brand, everything is extremely simple, the difficulties begin when it comes to the rest of the quality designations. It is about them that will be discussed further.

Classification of engine oils

Motor lubricating products are classified taking into account different methods and approaches, which together allows you to choose the best option for a particular engine. The basis of the oil, its viscosity, and quality characteristics are taken into account.

Classification of oils based on their basis

The base oil is the basis of motor lubrication and it is this oil that conveys its properties to the finished product. The additive package only corrects these properties to some extent. So the oil base could be as follows.

1. Mineral base is a product of the distillation of petroleum and is considered the oldest class. Mineral motor oil is not the best choice as this base is unstable and depends entirely on the starting material. During operation, a lot of deposits form in the engine, since the composition easily oxidizes and quickly loses its viscosity. In the cold, such a base thickens quickly. The option is the most budgetary and is suitable only for old motors.
2. Synthetic base is created specifically taking into account the required properties, among which there may be an increase in the resource, an improvement in protective properties, etc. In this case, the same oil is used, but the technological process of its processing is more perfect. Synthetic motor oil has improved properties and higher cost.
3. Semisynthetics- This is the same mineral base, but with the addition of a hydrocracked synthetic part, which improves performance. Some manufacturers call semi-synthetics and fully hydrocracked base. Either way, this is a good compromise in terms of quality characteristics. Also, semi-synthetic engine oil is less likely to provoke the formation of deposits in the engine and less often needs to be replaced. These advantages fully pay off the higher cost. It is not recommended to use such a product only in heavily contaminated engines, since due to the improved detergent properties, old dirt will rise from the oil channels and go further into the camshaft bed and into the crankshaft liners.

At first glance, you might get the impression that a semi-synthetic base is the best option and will provide the motor with the best resource. In fact, any oil works well if it matches the properties of the engine, and the driver observes the required drain intervals.

Viscosity classification (SAE standard)

The limits of the viscosity of the lubricant are determined by the design of the motor. Lubrication of loaded units occurs under pressure due to the oil pump, while spray from the camshafts and crankshaft provides lubrication of less loaded units.

The viscosity of the oil must be sufficient to build up pressure in the lubrication system, while the liquid state ensures the separation of micro-droplets of the substance to form an oil mist in the crankcase.

Compliance with the viscosity requirements is especially important in the case of modern engines, since the piston rings used in this case to reduce mechanical losses are not elastic enough, and if the oil is too viscous, it leaves a strong film on the cylinder walls, which the oil scraper rings remove worse. The result is an increase in consumption.

The viscosity index is influenced by temperature, therefore it is customary to indicate this parameter with two control points, which is what the generally accepted SAE classification is guided by. The measurement of the oil substance takes place at temperatures of -30 and 100 degrees, while we are talking about winter start-up and operating temperature.

There are several measurement ranges.

1. Summer viscosity corresponds to a number between 20 and 60, while the number 60 indicates the thickest oil.
2. For winter viscosity, numbers from 20 to 0 and the letter W (winter) are used. In a frost of -30 degrees, 0W oil will be the thinnest, and 20W the thickest.

The designation can be seasonal (summer or winter) or all-season. For example, SAE 50 is a 50 year old lubricant, SAE 10W is winter lubricant, and SAE 10W-40 is an all season lubricant. Markings 0, 5, 10, 15 and 20 with the letter W are for winter, and 20, 30, 40, 50 and 60 are for summer viscosity grades.

It is better to give preference to multigrade oils as they are more convenient to use. When choosing, you can underestimate the low-temperature viscosity.

High-temperature viscosity must necessarily comply with the manufacturer's requirements.

Viscosity according to GOST

Viscosity indicators are taken as a basis in the Russian classification according to GOST.

• summer classes correspond to the numbers 8, 10, 12, 14, 16, 20 and 24, which indicate the level of viscosity in square millimeters;
• numbers 4, 5 and 6 correspond to winter classes;
• When choosing a multigrade oil, also be guided by the number: the numerator will indicate the winter class, and the denominator will indicate the summer class.

API standards

The American Petroleum Institute (API) standard is used to define a characteristic list of properties, that is, designate product quality.

1. According to this standard, designations with the prefix C correspond to diesel engines, and the prefix S to gasoline engines (read about what it is).
2. The next letter will indicate the age of the standard edition (the further the letter in the alphabetical order, the more modern the edition). When choosing, you should not rely on more modern editions, since the standards are being tightened mainly due to the requirements of environmentalists, while the protective properties in relation to engine components may even deteriorate. For example, if the engine is designed for a product labeled API SJ, it will not perform better with SM / SN grease, since it has a lower phosphorus content and lower ash content, and these indicators are not important for an engine without a catalyst.

ACEA is a standard of the Association of European Automobile Manufacturers. Originally developed for European countries, but eventually found application in the global automotive market. According to this classification, there are three groups of engine lubricants.

• class A / B is suitable for gasoline and diesel engines of light commercial and passenger vehicles;
• class C - for gasoline and diesel engines that meet modern environmental standards;
• class E - for diesel engines of commercial vehicles that are operated under increased loads.

A number is indicated next to the letter in accordance with this standard. The higher its value, the higher the requirements for the product. The last two digits, separated by a hyphen, indicate the year the category was adopted.

Studying different motor oils, their brands and characteristics, we can conclude that the most famous brands in most cases prefer not to lose their reputation and continue to produce the highest quality products from year to year. Since there are always exceptions in most cases, you should carefully study the reviews before purchasing products. In any case, it is necessary to focus more on the recommendations of the car manufacturer's plant, and not on advertising slogans. As for the most reliable and proven brands, the following brands of motor oils are worth mentioning.

1. Shell HELIX... We are talking about high-quality synthetic lubricants, the advantage of which is represented by the presence in the composition of special detergent additives - they prevent the formation of carbon deposits and keep the inside of the engine almost sterile. The range is wide and allows you to make a choice, taking into account any type of motor. Lubricants of this brand are not only environmentally friendly due to the minimum concentration of chlorine, but even exceed the requirements of modern standards.
2. Castrol... On the account of this brand twenty record achievements, including the promotion of the Formula-1 motor to 19,000 rpm in 2002. The range of products is no less diverse and includes both mineral and synthetic base greases. Fluids are produced, both with diesel and gasoline engines, and with automatic and manual transmissions. Impurities in this case are completely absent and this is a huge achievement.
3. LUKOIL... The range of lubricating fluids exceeds 200 types, among which you can choose an option for any type of engine. There are separate categories for special equipment and trucks.
4. Xado supplies its products to fifteen countries around the world, provides protection against counterfeiting and reliable metal packaging. The range is represented by fluids for all types of engines, not only for cars, but also for motorcycles, hydromechanical structures, compressors and refrigeration equipment.
5. Liqui moly- a concern whose activities are focused on the production of transmission and engine fluids. Manufacturing facilities are concentrated only in Germany, which minimizes the likelihood of counterfeiting.
6. Esso produces lubricants on all types of bases (synthetic, mineral, semi-synthetic) and is distinguished by an almost jewelry definition of the ratio of additives. The products have been tested and satisfied with such global automotive brands as Volkswagen, Audi and Mercedes.

You might also be interested in our expert's article on performance.

Many years ago, in 1873, Professor John Ellis was able to obtain motor oil for the first time. He spent a lot of time studying the characteristics of crude oil. Numerous experiments led him to conclude that it has excellent lubricating characteristics.

By adding the manufactured lubricant to the valve train of steam engines, he noticed that the movement of the valves was much smoother. The wear of parts has decreased, the operating time of the power plant has increased. John registered his discovery and opened the world's first production of motor lubricants.

Manufacturing technology

It all starts with the extraction of crude oil. It is filtered, where it is cleaned of harmful components. All operations are performed at specialized enterprises with the appropriate equipment. Motor oils are divided into several types, each of which differs in components and properties.

Mineral ones are considered the cheapest. They are made from crude oil that is filtered and standardized. Synthetic are the most expensive class. They are based on substances obtained after complex chemical manipulations with products from gas and oil. The hybrid of the above-described compositions came to be called semisynthetics.

How motor oil is made: the manufacturing process

The modern process for the manufacture of lubricants for the latest technology is subdivided into several stages. First, the preparation of raw materials is carried out, from which certain oil fractions are obtained. To obtain components of motor oils, special technological units are used that process oil in accordance with flow schemes.

After distillation of oil, distillate fractions of oil are obtained:

• 350-420 degrees;
• 420-500 degrees;
• More than 500C.

The modern oil refining industry opens up new possibilities for distillation using the minimum fractional composition. The result is a lot more base oils.

At the next stage, all fractions are purified in special oil block installations. Moreover, cleaning can be performed in various ways. Selective purification of the available oil fractions is mainly carried out. To do this, use:

1. A mixture of tricresol with phenol;
2. Deasphalted, which is part of propane.

The result is a residual oil fraction raffinate. It is hydrotreated in a standing catalyst. Residual raffinate is produced at a temperature of more than 500 ° C. At the final stage, commercial oils are obtained by compounding oil components and special additives.

More and more high-end cars appear on the roads every day. Of course, engine oil manufacturers take this factor into account. Each car manufacturer creates a specific technical task for the manufacture of the latest lubricant, corresponding to the characteristics of the car engine. It must reliably protect the propulsion system and extend its service life.

Of course, the technology described above is of a general nature. Every lubricant manufacturer tries to keep the technology of obtaining the latest oil secret. This is the only way to stay afloat in an age of fierce competition.

Each car owner should be able to decipher the marking of the engine oil applied to the product packaging, because the guarantee of durable and stable engine operation is the use of a high-quality engine that meets all the requirements of the manufacturing plant. Such serious requirements are imposed by them due to the fact that oils have to work in a wide temperature range and under high pressure.

From this article, you will learn:

Engine oil marking contains all the necessary information for the correct choice, you just need to be able to decipher it

In order to streamline and simplify the procedure for selecting oil for a specific type of engine according to the required characteristics and tasks assigned to it, a number of international standards have been developed. World oil producers use the following generally recognized classifications:

• ACEA;
• ILSAC;
• GOST.

Each of the types of oil labeling has its own history and market share, the decoding of the meaning of which allows you to navigate in the choice of the necessary lubricating fluid. Basically, we use three types of classification - API and ACEA, as well as, of course, GOST.

There are 2 main classes of engine oils, depending on the type of engine: gasoline or diesel, although there is also a universal oil. The intended use is always indicated on the label. Any engine oil consists of a base composition (), which is its base, and certain additives. The basis of the lubricating fluid is oil fractions, which are obtained during oil refining or artificially. Therefore, by chemical composition, they are divided into:

• mineral;
• semi-synthetic;
• synthetic.

On the canister, along with other markings, the chemical is always indicated. composition.

What may be on the oil canister label:

1. Viscosity grade SAE.
2. Specifications (edit) API and ACEA.
3. Tolerances car manufacturers.
4. Barcode.
5. Batch number and production date.
6. Pseudo-labeling (not a generally recognized standard labeling, but used as a marketing ploy, for example, fully syntetic, HC, with the addition of smart molecules, etc.).
7. Special categories of motor oils.

To help you buy the one that works best for your car's engine, we'll decipher the most important engine oil markings.

SAE Engine Oil Labeling

The most important characteristic that is indicated in the marking on the canister is the SAE viscosity index, which is an international standard that regulates at plus and minus temperatures (boundary value).

In accordance with the SAE standard, oils are indicated in the XW-Y format, where X and Y are some numbers. First number- this is a symbol of the minimum temperature at which the oil is normally pumped through the channels, and the engine turns without difficulty. The letter W means the English word Winter - winter.

Second number conventionally means the minimum and maximum value of the high-temperature viscosity limit of the oil when it is heated to the operating temperature (+ 100 ... + 150 ° С). The higher the number, the thicker it becomes when heated, and vice versa.

Therefore, oils are necessarily divided into three types depending on the viscosity value:

• winter oils, they are more fluid and provide trouble-free starting of the engine in the cold season. In the designation of the SAE index of such an oil, the letter "W" will be present (for example, 0W, 5W, 10W, 15W, etc.). To understand the boundary value, you need to subtract the number 35. In hot weather, such oil is not able to provide a lubricating film and maintain the required pressure in the oil system due to the fact that at high temperatures its fluidity is excessive;
• summer oils are used when the average daily temperature is not lower than 0 ° C, since its kinematic viscosity is high enough so that in hot weather the fluidity does not exceed the required value for good lubrication of engine parts. At subzero temperatures, starting an engine with such a high viscosity is impossible. Summer brands of oils are indicated by a numerical value without letters (for example: 20, 30, 40, and so on; the higher the number, the higher the viscosity). The density of the composition is measured in centistokes at 100 degrees (for example, a value of 20 indicates a boundary density of 8-9 centistokes at an engine temperature of 100 ° C);
• all-season oils the most popular, since they are able to operate at both minus and plus temperatures, the boundary value of which is indicated in the decoding of the SAE indicator. This oil has a double designation (example: SAE 15W-40).

When choosing an oil viscosity (from those approved for use in the engine of your car), you need to be guided by the following rule: the more mileage / older the engine, the higher the high-temperature viscosity of the oil should be.

Viscosity characteristics are the very first and most important element of the classification and labeling of engine oils, but not the only one - choosing an oil purely by viscosity is not correct... Is always it is necessary to choose the right property relation oil and its operating conditions.

Each oil, in addition to viscosity, has a different set of performance properties (detergent, antioxidant, antiwear, tendency to form various deposits, corrosiveness and others). They allow you to determine the possible area of ​​their application.

In the API classification, the main indicators are: engine type, engine operating mode, oil performance, conditions of use and year of manufacture. The standard provides for the separation of oils into two categories:

• Category "S" - shows intended for gasoline engines;
• Category "C" - indicates the purpose for diesel vehicles.

How do I decode API markings?

As already found out, the API designation can begin with the letter S or C, which will speak of the type of engine into which you can fill, and another letter of the oil class designation, indicating the level of performance.

According to this classification, the decoding of the marking of engine oils is carried out as follows:

• abbreviation EC which is right after the API, denote energy saving oils;
• Roman numerals after this abbreviation talk about the level of fuel economy;
• letter S(Service) denotes applications petrol engine oils;
• letter C(Commercial) are indicated by;
• after one of these letters follows performance level indicated by letters from A(lowest level) to N and further (the higher the alphabetical order of the second letter in the designation, the higher the oil class);
• universal oil has letters of both categories across the oblique line (for example: API SL / CF);
• API markings for diesel engines are divided into two-stroke (number 2 at the end) and 4-stroke (number 4).

Those motor oils, who passed API / SAE test and meet the requirements of the current quality categories, indicated on labels with a round graphic symbol... At the top there is an inscription - "API" (API Service), in the middle is the SAE viscosity, as well as the possible degree of energy saving.

When using oil according to its "own" specification, wear and tear and the risk of engine breakdown are reduced, oil wastage, fuel consumption, noise is reduced, engine performance is improved (especially at low temperatures), and the service life of the catalyst and exhaust purification system is increased.

ACEA, GOST, ILSAC classifications and how to decipher the designation

The ACEA classification was developed by the Association of European Automobile Manufacturers. It indicates the performance properties, purpose and category of engine oil. ACEA classes are also divided into diesel and gasoline.

The latest edition of the standard provides for the division of oils into 3 categories and 12 classes:

• A / B – gasoline and diesel engines cars, vans, minibuses (A1 / B1-12, A3 / B3-12, A3 / B4-12, A5 / B5-12);
• C – gasoline and diesel engines with catalyst exhaust gases (C1-12, C2-12, C3-12, C4-12);
• E – diesel engines for trucks(E4-12, E6-12, E7-12, E9-12).

In addition to the engine oil class, the ACEA designation indicates the year of its introduction into force, as well as the edition number (when the technical requirements were updated). Domestic oils are also certified according to GOST.

Classification of engine oils according to GOST

According to GOST 17479.1-85, motor oils are divided into:

• kinematic viscosity classes;
• performance groups.

By kinematic viscosity oils are divided into the following classes:

• summer - 6, 8, 10, 12, 14, 16, 20, 24;
• winter - 3, 4, 5, 6;
• all-season - 3/8, 4/6, 4/8, 4/10, 5/10, 5/12, 5/14, 6/10, 6/14, 6/16 (the first number indicates the winter class, the second for summer).

In all of these classes, the higher the numerical value, the higher the viscosity.

By area of ​​application all engine oils are divided into 6 groups - designated from the letter "A" to "E".

Index “1” denotes oils intended for gasoline engines, index “2” - for diesel engines, and oils without an index indicate its versatility.

ILSAC classification of engine oils

ILSAC is a joint invention of Japan and America, the International Committee for Standardization and Approbation of Motor Oils has issued five standards for motor oils: ILSAC GF-1, ILSAC GF-2, ILSAC GF-3, ILSAC GF-4 and ILSAC GF-5. They are completely similar to API classes, the only difference is that oils corresponding to the ILSAC classification are energy-saving and all-season. This classification is best for Japanese cars.

Correspondence of ILSAC categories regarding API:

• GF-1(obsolete) - oil quality requirements similar to API SH category; by viscosity SAE 0W-XX, 5W-XX, 10W-XX, where XX-30, 40, 50,60.
• GF-2- meets the requirement by oil quality API SJ, and viscosity SAE 0W-20, 5W-20.
• GF-3- is an analogous to the API SL category and put into operation since 2001.
• ILSAC GF-4 and GF-5- respectively analogs of SM and SN.

In addition, within the framework of the standard ISLAC for Japanese cars with turbocharged diesel engines, used separately JASO DX-1 class... This marking of automotive oils provides engines of modern cars with high environmental parameters and built-in turbines.

The API and ACEA classifications formulate minimum baseline requirements that are agreed upon between oil and additive manufacturers and vehicle manufacturers. Since the designs of engines of different brands differ from each other, the operating conditions of the oil in them are not quite the same. Some major engine manufacturers have developed their own classification system motor oils, so-called tolerances which complements the ACEA classification system, with its own test engines and field tests. Engine manufacturers such as VW, Mercedes-Benz, Ford, Renault, BMW, GM, Porsche and Fiat predominantly use their own approvals when choosing an engine oil. The operating instructions for the car must contain specifications, and their numbers are applied to the packaging of the oil, next to the designation of its class of performance properties.

Consider and decipher the most popular and frequently used tolerances present in the designations on canisters with engine oils.

VAG approvals for passenger cars

VW 500.00- energy-saving engine oil (SAE 5W-30, 10W-30, 5W-40, 10W-40, etc.), VW 501.01- all-season, intended for use in conventional gasoline engines manufactured before 2000, and VW 502.00 - for turbocharged ones.

Tolerance VW 503.00 provides that this oil is for gasoline engines with a viscosity of SAE 0W-30 and with a keen replacement interval (up to 30 thousand km), and if the exhaust system is with a three-component neutralizer, then oil with VW 504.00 tolerance is poured into the engine of such a car.

For Volkswagen, Audi and Skoda cars with diesel engines, a group of oils with tolerances is provided VW 505.00 for TDI engines manufactured before 2000; VW 505.01 recommended for PDE engines with unit injector.

Energy saving engine oil with viscosity grade 0W-30 with a tolerance VW 506.00 has an extended replacement interval (for V6 TDI engines up to 30 thousand km, 4-cylinder TDI up to 50 thousand). Recommended for use in new generation diesel engines (after 2002). For turbocharged engines and unit injector PD-TDI, it is recommended to fill with oil with a tolerance VW 506.01 having the same extended drain interval.

Mercedes passenger car approvals

The auto concern Mercedes-Benz also has its own approvals. For example, engine oil marked MB 229.1 intended for diesel and gasoline engines Mercedes manufactured since 1997. Tolerance MB 229.31 introduced later and meets the SAE 0W-, SAE 5W- specification with additional requirements that limit the sulfur and phosphorus content. MB 229.5 Is an energy saving oil with extended service life for both diesel and gasoline engines.

BMW engine oil approvals

BMW Longlife-98 such an admission is possessed by motor oils intended for filling into the engine of cars manufactured since 1998. Extended service interval is provided. Meets basic ACEA A3 / B3 requirements. For engines manufactured at the end of 2001, it is recommended to use oil with a tolerance BMW Longlife-01... Specification BMW Longlife-01 FE provides for the use of a motor oil when operating in harsh conditions. BMW Longlife-04 approved for use in modern BMW engines.

Renault engine oil approvals

Tolerance Renault RN0700 was introduced in 2007 and meets the basic requirements: ACEA A3 / B4 or ACEA A5 / B5. Renault RN0710 meets the requirements of ACEA A3 / B4, and Renault RN 0720 by ACEA C3 plus additional Renault. RN0720 approval designed for use in latest generation diesel engines with particulate filters.

Ford approval

SAE 5W-30 approved motor oil Ford WSS-M2C913-A, intended for initial and service replacement. This oil meets the ILSAC GF-2, ACEA A1-98 and B1-98 classification and additional Ford requirements.

Oil with tolerance Ford M2C913-B intended for initial filling or service replacement in gasoline and diesel engines. Also meets all ILSAC GF-2 and GF-3, ACEA A1-98 and B1-98 requirements.

Tolerance Ford WSS-M2C913-D was introduced in 2012 and is recommended for all Ford diesel engines with the exception of Ford Ka TDCi models manufactured before 2009 and engines manufactured between 2000 and 2006. Provides the possibility of an extended drain interval and refueling with bio-diesel or high-sulfur fuels.

Certified oil Ford WSS-M2C934-A provides extended drain intervals and is intended for use in vehicles with a diesel engine and a particulate filter (DPF). Ford WSS-M2C948-B, based on ACEA C2 class (for gasoline and diesel engines with catalytic converter). This tolerance requires an oil with a viscosity of 5W-20 and reduced soot formation.

When choosing an oil, you need to remember several main points - this is the correct choice of the required chemical composition (mineral water, synthetics, semisynthetics), the viscosity classification parameter, and know the necessary requirements for the set of additives (defined in the API and ACEA classifications). Also, the label should contain information for which brands of machines this product is suitable. It is equally important to pay attention to the additional designations of the engine oil. For example, the Long Life mark indicates that the oil is suitable for machines with an extended service interval. Also among the features of some formulations can be distinguished compatibility with engines that have a turbocharger, an intercooler, cooling of recirculation gases, timing control and valve lift.

For a person who is concerned about what he is pouring into the engine of his car, information on the composition of engine oil will be very useful. This knowledge will give a clue to what the oils on store shelves are made of, and why one is one and a half times cheaper than the other, although both say "synthetic oil". We have already touched on this topic a little earlier, now it is time to talk about this topic in more detail.
As I already mentioned in the article about, in a first approximation, the oil consists of a base base (base oil), a viscosity modifier responsible for maintaining the viscosity within specified limits and additives that determine the presence of various useful oils in oils. By the way, this viscosity modifier sometimes scares motorists a lot when they try to pour oil into the car in the cold.

Base oil.

Base oil is the base that determines how long a product will last in an engine and is responsible for its lubricating properties. Plus, it serves as a carrier medium for the additives. There are five main types of base oils:

• mineral
• mineral selective purification
• hydrocracking (HC)
• polyalphaolefin (PAO)
• etheric (esters)

Mineral bases are obtained by selecting the appropriate petroleum fractions during oil distillation. Selective oils are additionally refined with selective solvents (hence the name), which wash out the most inappropriate molecules from the base, improving the composition of the engine oil, making it more homogeneous.

The hydrocracking base is also obtained from mineral raw materials, but at the same time synthesis processes are used, that is, conversion into hydrocarbons of the required structure. Therefore, this base is considered synthetic. By the way, it was referred to synthetics not so long ago, ten to fifteen years ago, all the leading oil brands in the product line had two semisynthetics, with a viscosity of 10w-40 and 5w-40, higher than which were premium oils on PJSC -based. About five years ago, a layer of oils appeared between them, declared as synthetic, but cheaper and not inheriting the form of the name of premium products (for example, the number 1 in the name Mobil, or the word Ultra for Shell, Edge for Castrol, etc.). This was the moment when hydrocracking came to be considered synthetics. From a marketing point of view, it's a good move: consumers think that synthetics have been made cheaper for them, but in fact they simply began to sell more expensive what used to be called semi-synthetics. As they say, the wolves are fed and the sheep are safe.

Polyalphaolefins, or PAO for short, are the most expensive and most common synthetic base for the production of technical oils. It is produced from ethylene, synthesizing molecules of a given shape and properties. This has a number of advantages:

I will dwell on the last aspect in more detail. Oil molecules (any) when working in an engine experience heavy loads, as a result of which they are destroyed, turning into debris that contaminates the oil. Since the mineral base consists of dissimilar molecules (roughly speaking, a mixture of petroleum fractions in the distillation temperature range of 300-600 degrees, naturally having different properties), then they will decompose in different ways: some earlier, others later. At the same time, after the disintegration of less stable molecules, the physical properties of the oil in general change for the worse: after all, the composition of the oil has changed, plus garbage has been added from the remnants of the disintegrated molecules. And this process occurs constantly from the moment new oil is filled, so that as the operation progresses, the level of performance properties smoothly creeps down.

Due to their uniformity and stability, synthetic molecules withstand all engine loads (if they do not exceed the calculated ones), therefore they do not disintegrate, respectively, the base in the oil, almost the entire set mileage has a state like that of freshly poured oil (I emphasize that we are talking about the base , visually it will not manifest itself in any way, well, or almost nothing. The oil will still darken due to the work of detergents). However, PAO also does not last forever and wears out, so at one point the molecules will nevertheless begin to disintegrate. And practically at the same time, they are the same, and their wear resistance is also the same. So it is very important to change the oil before this moment, because starting from it, your engine will work on working off, which will adversely affect its resource up to failure.

The essential, or ester base, is also made by means of synthesis, which is more complex and expensive than PAO, so oils on it are not very common. Of the companies that declare the production of essential oils, only Motul comes to mind. Of course, there are also a bunch of oils with esters, but usually in one or two positions, but not in every brand. Esters differ from PAO in the presence of excellent lubricating properties, but poor resistance to water. And here a revelation awaits us: it turns out that there is no ideal basis for engine oil, everyone has their own drawbacks (see the plate).

As you can see from the table, any type of base oil has "twos" or "threes". Manufacturers see a way out in mixing the bases for mutual neutralization of negative indicators. The most technically good option is with a mixture of PAO and ethers, but the price in this case becomes not so much a "two" - "one". Although for many motorists this is not a reason to pour something worse than the most perfect oil into your favorite car :). Since there are few such people, all kinds of mixtures of PAO, mineral water and hydrocracking are made for the rest. The main conclusion from this is this: even if the oil is written fully synthetic (which means "fully synthetic"), in fact, it is most likely synthetic by fifty percent +/-. As I mentioned in another article, at a technical seminar, a representative of one of the major (in the sense of the main) brands said that their oil is considered synthetic if the share of synthetics in it is more than 35%. So for reasons of altruism of "extra PAO" no one pours us, be sure.

Oil additives.

With the base sorted out, we turn to the additives that are part of the engine oil. All additives are divided into 3 groups:

• viscosity modifiers
• oil protection additives
• additives for protecting the engine surface

Viscosity modifiers.

This group includes the viscosity modifier itself, which is responsible for maintaining the calculated viscosity with increasing temperature, and a depressant additive, which maintains the viscosity within specified limits at low temperatures. Read more about this in the article about. Here we will mention that the viscosity modifier is remarkable in that it should be much more in the oil than other additives, as a rule, about 10% of the total oil volume, while all other additives taken together make up another 10%.

Oil protection additives.

In addition to physical and thermal decomposition with oil in the engine, two troubles can occur that will interfere with its high-quality operation. This is foaming and oxidation (or chemical destruction). Therefore, they add to the oil anti-foam and antioxidant additive (antioxidant). An antifoam additive reduces the surface tension coefficient of the oil, so bubbles that form during foaming burst immediately.

The situation with oxidation is as follows: it is known from the school chemistry course that acids are neutralized by alkalis. So to combat oxidation (that is, the effect of acids on the oil), additives are added to the oil that have an alkaline medium and neutralizing acids. The main indicator of the neutralizing properties of the oil is the base number. It is designated by the abbreviation TBN - "total base number", where total - in this case means general, base - alkaline, since alkalis in chemistry are also called bases, who do not remember :), but number is a number. The TBN value is the amount of potassium hydroxide (KOH) in milligrams, equivalent in neutralizing effect to the additives contained in one gram of oil. Such is the squiggle, as they say :). By the way, there is a very interrelated characteristic of the oil - the acid number. It is expressed in the same milligrams of KOH, but in a slightly different way. This is the amount of potassium hydroxide needed to neutralize all acids contained in 1 gram of oil. To assimilate these tricky maxims, I will try to explain "on the fingers". Let's say the base number of the oil at the beginning of use is 7, and the acid number is 1.5. This means that acids are completely neutralized and there is still a large margin of safety. As antioxidants are produced, the base number will decrease and the acid number will increase. When they become equal, the oil will not have a margin of safety and in the future it will not be able to fight oxidation processes, which means it will begin to actively turn into unusable waste. This oil needs to be changed urgently.

Additives for protecting engine surfaces.

Now let's see how the oil protects our engine. The motor is guarded by:

• antiwear additives
• friction modifiers (antifriction additives)
• extreme pressure additives
• detergents (detergents)
• dispersants
• anti-corrosion additives

Let's go over the functions and the principle of operation. Sulfur compounds are often used as antiwear additives, which at high loads and temperatures form a film of iron sulfide on the surface of the part, which is very resistant to wear of the joint. So sulfur, which a European organization called ACEA (Association des Constracteurs Europeens des Automobiles) is trying to get rid of automobile oils in the name of ecology, is very much needed in the engine in reasonable quantities, since it protects it from wear. There is a reservation about the quantity, since in addition to protecting the engine, it is also a component of the formation of sulfuric acid, which the antioxidant additive already has to fight with. Such is the relationship.

Antifriction additives (friction modifiers) are needed to reduce friction (wow :)) in the engine. Molybdenum disulfide is widely used in this capacity (there are even oils that stand out on the label, Mannol, for example, LiquiMoly ...). In oil, this material settles on the surface of parts and, when they come into contact with each other, stratifies like graphite (due to the peculiarities of its molecular structure) under low loads, thus reducing friction losses.

EP additives work where wear occurs as a result of the cyclic repetition of shock loads (for example, a cam-follower pair in a timing belt). The force of the cam is such that the upper layer of the follower is destroyed on contact. To prevent this from happening, a protective film of an additive forms on the pusher, which is destroyed instead of metal when the cam strikes, but immediately forms again. The use of antiwear and extreme pressure additives at the same time is due to the fact that each of them is most efficient in different conditions. Some cope better with high voltages, others withstand high temperatures, etc.….

Detergents are additives that remove deposits from the engine and prevent re-contamination. Their molecules attach to sediment particles and form an electrically charged shell that pushes the dirt out into the oil. They are also able to attach to the surface of metals and repel dirt particles, preventing them from re-settling on the engine.

Dispersing additives work by catching insoluble particles in the oil and enveloping them, keeping them in suspension, preventing them from settling somewhere in a nook and forming a layer of dirt in the engine. I will not bore you by listing the names of these additives, personally I hardly perceive all this alkylphenol and succinimide terminology, and we don't need it here.

Anti-corrosion additives prevent corrosion of non-ferrous metals in the engine by forming a film on their surface that is not destroyed by friction under the influence of detergents and weak acids formed during engine operation. In order not to confuse antioxidant and anticorrosive effects, it is enough to remember that antioxidants protect the oil, and anticorrosive additives protect engine parts. Moreover, many additives combine these two effects.

Here is a schematic diagram of the composition of the additive package.

Multifunctionality and synergy.

In general, it should be borne in mind that very often additives have a complex effect, combining two or more of the above functions. For example, zinc dithiophosphates were noted in almost all of the described properties (with the exception of viscosity). Another thing is that each additive has a primary action and a secondary one. At the same time, several different additives can be used to provide the same function in different engine components. You also need to take into account such a phenomenon as synergy and its inverse antagonism. Several additives can be used together to produce additional effects that exceed the simple sum of the individual effects, and this is the synergistic effect. However, it can be the other way around, the two additives mutually neutralize the actions of each other. In addition, many additives, having the main positive effect, give subsidence in other parameters, and something else has to be added to neutralize it. Oil manufacturers spend a lot of time and energy trying to select an additive composition with the optimal synergistic effect at a reasonable cost. It looks like a lot of experimental mixes with their subsequent testing and analysis of the results. That is why none of the manufacturers strongly recommends adding foreign additives / additives to their oils. It is not known what the overall effect will be with this new mixture, it may turn out that all this painstaking work went down the drain. So in this case it makes sense to listen to them and not tempt fate. Although, of course, if there is a sufficient baggage of knowledge, a clear idea of ​​what and why you are uploading, and an understanding of the possible negative consequences, then why not. In the end, the dosage of additives is calculated with a certain reserve, which, for example, is spent on neutralizing the non-draining oil residue after replacement, and in which case, can mitigate the consequences of such experiments.