Engine oils are selected based on two main technical parametersof paramount importance for the engine: viscosity grade and operating class.

Viscosity should be understood as a parameter characterizing the ability of liquid molecules to move relative to each other, while maintaining a molecular bond. On a liquid scale, viscosity is understood as the property of different layers of a lubricant to move relative to each other with a certain index of internal friction. The higher the intermolecular friction index, the higher the viscosity parameter of the engine oil.

The international standard SAE J300 regulates all requirements for the viscosity grade of engine oil. The optimal indicator is selected in accordance with the design of the mechanisms, engine operating modes, periods of active operation, external operating conditions.

The operating class is understood as a parameter that determines the quality indicators of the oil itself. Implementation the latest systems and technology in all areas of mechanical engineering has led to the fact that more and more stringent requirements are imposed on engine oil. To give each engine exactly the lubricant that will provide it with the most efficient operation, special classification systems have been developed motor oils... Each of which subdivides the entire range of petroleum products into categories and series, depending on the purpose of each and the level of their quality.

The most popular classifications of oils

• KAPI - classification developed by the American Petroleum Institute, the name comes from the corresponding abbreviation.
• ILSAC - the classification was developed by the International Lubricant Standardization and Approval Committee for engine oils.
• - the classification was developed by the European Automobile Manufacturers Association, the name is also formed from the abbreviation - (Association des Cunstructeurs Europeens d'Automobiles)

The only system recognized worldwide is the SAE classification developed by the Society of AutomotiveEngineers.
It was this classification that most fully described the relationship between temperature and viscosity of engine oil during its operation in a car engine. In total, the classification includes 12 different classes for seasons, six for each season.
In this classification, oils are divided into two categories:

• Summer SAEs do not have letter designations, but only numbers from 20 to 60, which determine the viscosity index. This category includes only oils with a high viscosity index, which allow the engine to operate effectively at high ambient temperatures.
• Winter SAE, marked with digital designations and the Latin letter W. The figure shows the degree of viscosity and varies from 0W to 25W. Low-viscosity oils are used for low-temperature operation.

Depending on the ambient temperature, the temperature of different parts of the engine, the viscosity parameter for the same fluid changes in proportion to cooling or heating, since this accelerates or slows down the movement of the lubricant molecules.

SAE summer grease allows reliable lubrication even in high temperature conditions, but becomes a real obstacle to the normal operation of mechanisms at low temperatures. As a result, the process of starting the engine becomes much more difficult.
SAE winter lubrication allows for easy engine start when operating in low temperatures, but is completely unable to provide reliable lubrication at high temperatures or high engine loads.

What are the cool brands worth?

The optimal solution for any season

The solution to the problem of changing oils during the transition from season to season became possible thanks to the appearance on the market of a new product - SAE multigrade engine oil. The special formula allows you to effectively use such oils in all weather conditions. The general classification table contains two markings at once in the designation of all-season oil, both for winter and summer types (5W - 30; 10W - 40). The peculiarity of these types of oils is that when the temperature drops, the lubricating fluid behaves in the same way as summer types, and when the ambient temperature drops, it acquires all the properties of winter types of lubricants.

Multigrade oil is created on the basis of two basic principles: first, it should not exceed the low-temperature characteristics of the dynamic viscosity; secondly, the kinematic viscosity should be within the operating parameters at a temperature of 100 ° C.

Main parameters characterizing low-temperature properties according to SAE

The oversteer indicator determines the parameters of oil flow at low temperature conditions. This parameter should be understood as the maximum permissible level of oil viscosity during engine start-up while operating at low temperatures. The oversteer must be sufficient to turn the crankshaft at such a speed that the engine can start.

The pumpability index is expressed by the value of the dynamic viscosity index for the temperature regime of each specific class. This parameter should not exceed 60,000 mPa * s, but at the same time it should provide pumping through the oil circulation system. Measured with an MRV mini-rotational viscometer. In practice, it is measured at temperature conditions 5 ° C less than the calculated one, while the engine should not suck in air from the external environment.

High-temperature viscosity is characterized by the following indicators

The kinematic viscosity index is measured at a temperature of 100 ° C. This parameter, for multigrade oil, should not go beyond the specified range. Since with a decrease in viscosity, premature wear of rubbing surfaces, such as a bearing, will occur, crankshaft, camshaft, crank mechanism. And in case of exceeding the upper limit, it causes oil starvation and also premature wear and failure of the mechanical part of the engine.

Comparison of oils at a temperature of -35

Dynamic viscosity index HTHS

Shows how stable the viscosity characteristic of the grease is when operating under extreme operating conditions (high temperature mode). It is one of the main parameters characterizing the energy-saving properties of motor oils.

Depending on the type of material, all engine oils are classified into three main types of classification:

1. Mineral based lubricantsobtained by distillation of waste oil products or from agricultural crops. This category is characterized by fast evaporation and low resistance to chemical processes and low resistance to various influences. Viscosity index in mineral oils high enough. But such oils will be used up quickly.
2. Synthetic based lubricating fluids... For these oils, the main feature is the low viscosity grade. Manufacturing technology is based on oil refining and subsequent chemical processing. Such oils are much less susceptible to aggressive environments, they are more stable and provide reliable protection for engine parts.
3. Semi-synthetic lubricants consist of a mixture of mineral and synthetic oils and are outstanding representatives of all-season machine lubricants.

What do car manufacturers recommend to consider when choosing oil for different temperature conditions?

Before choosing an engine oil initially, you should carefully read the factory instructions and the manufacturer's recommendations. Recommendations and instructions are drawn up on the basis of design features mechanisms of engines, such as the degree of load on lubricants, the indicator of the hydrodynamic resistance of the oil system, the indicator of the pump performance for pumping the lubricant. Some manufacturers produce lubricants approved for operation in a certain temperature region.

Before purchasing engine oil, it is necessary to check the Classification on the label with the data in the manufacturer's instructions. Consider the SAE 5W40 all-season grade as an example. In this case, the Latin letter W indicates that this type of lubricant can be used in winter conditions. The first number 5 indicates the lowest temperature at which the lubricant will be able to cope with the tasks assigned to it. In order to get the real temperature, it is necessary to add the figure 5 to the temperature - 40 ° C, which means that this type of grease has a lower limit of - 35 ° C. The second number in the label indicates the upper temperature limit. In this case, the upper limit is + 40 ° C.

It should be noted right away that from the list of classification of oils, the car owner should pay special attention to precisely those brands that are suitable specifically for his engine and are recommended by the manufacturer. Otherwise, the use of grease with parameters different from the parameters set by the manufacturer will lead to breakdowns and failure of individual parts or the entire engine.

The currently recognized international viscosity grading system for engine oils is SAE J300, developed by the Society of Automotive Engineers. The viscosity of the oil in this system is expressed in conventional units - degrees of viscosity. The higher the SAE number, the higher the viscosity of the oil.

The specification describes three ranges of viscosity of oils: winter, summer and all-season. But, before considering them, a little theory. Temperature Range Motor oil is mainly determined by two of its characteristics: kinematic and dynamic viscosity. Kinematic viscosity is measured in a capillary viscometer and indicates how easily oil flows at a given temperature by gravity in a thin capillary tube. Dynamic viscosity is measured in more sophisticated installations - rotary viscometers.

It shows how much the oil viscosity changes when the speed of movement of the lubricated parts relative to each other changes. With an increase in the speed of relative movement of the lubricated parts, the viscosity decreases, and with a decrease, it increases.

Row winter oils : SAE 0W, 5W, 10W, 15W, 20W, 25W - designated by a number and the letter “W” (Winter-Winter). For winter classes, two maximum values \u200b\u200bof low-temperature dynamic viscosity and a lower limit of kinematic viscosity at 100 ° C are established.

Low-temperature parameters include:

• Understeer- shows the dynamic viscosity of the engine oil and the temperature at which the oil
  remains liquid enough to start the engine.
• Pumpability - this is the dynamic viscosity of the oil, at which the oil can be pumped through the lubrication system and the engine will not operate in dry friction mode. The pumping temperature is 5 degrees lower than the cranking temperature.

The high-temperature properties of winter oils are characterized by the minimum kinematic viscosity at 100 ° C - an indicator that determines the minimum viscosity of the engine oil when the engine is warm.

Row summer oils: SAE 20, 30, 40, 50, 60 - indicated by a number without a letter designation. The main properties of the summer range of oils are determined by:

• minimum and maximum kinematic viscosities at 100 ° C - an indicator that determines the minimum and maximum viscosity of the engine oil with a warm engine.
• minimum viscosity at 150 ° C and a shear rate of 106 s-1. The shear rate gradient is the ratio of the speed of movement of one friction surface relative to the other to the size of the gap between them, filled with oil. As the shear rate increases, the viscosity of the oil decreases, but it rises again when the shear rate decreases.

Row multigrade oils: SAE 0W-20, 0W-30, 0W-40, 0W-50, 0W-60, 5W-20, 5W-30, 5W-40, 5W-50, 5W-60, 10W-20, 10W-30, 10W-40, 10W-50, 10W-60, 15W-30, 15W-40, 15W-50, 15W-60, 20W-30, 20W-40, 20W-50, 20W-60. The designation consists of a combination of the winter and summer series, separated by a dash. t

All-season oils must meet both the criteria for both winter and summer oil... The lower the number in front of the letter W, the lower the viscosity of the oil at low temperatures, the easier cold start of the engine with a starter, and the better the pumpability of the oil through the lubrication system. The larger the number after the letter W, the higher the viscosity of the oil at high temperatures and the more reliable engine lubrication when hot.
the weather.

Thus, the SAE class informs the consumer about the ambient temperature range in which the oil will provide:

• cranking the engine with a starter (for winter and multigrade oils)
• pumping oil by an oil pump through the engine lubrication system under pressure during cold start-up in a mode that does not allow dry friction in friction units (for winter and all-season oils)
• reliable lubrication in summer during long-term operation at maximum speed and load mode (for summer and all-season oils)

Classification of engine oils by purpose and API performance levels

The most famous international classification of motor oils in terms of application and level of performance is the API (American Petroleum Institute) classification.

The API classification divides engine oils into two categories:

• S (Service) - for gasoline engines passenger carsmobiles, vans and light trucks.
• C (Commercial) - for diesel engines commercial vehicles (trucks), industrial and agricultural tractors, road construction equipment.

The oil class designation consists of two letters of the Latin alphabet: the first (S or C) indicates the oil category, the second - the level of performance properties. The further from the beginning of the alphabet the second letter, the higher the level of properties (i.e. oil quality).

Classes diesel oils are further subdivided for two-stroke (CD-2, CF-2) and four-stroke diesel engines (CF-4, CG-4, CH-4). Most foreign engine oils are universal - they are used in both gasoline and diesel engines. These oils have a double designation, for example: SF / CC, CD / SF, etc. The main purpose of the oil is indicated by the first letters, i.e. SF / CC - "more petrol", CD / SF - "more diesel". Energy-saving oils for gasoline engines are additionally designated by the abbreviation EU (Energy Conserving).

As of today (April 2009) the API classification contains 3 valid classes of category "S" and 6 valid classes of category "C". But many manufacturers continue to produce oils of the classes excluded from the specification, as cars with old engines continue to operate, which means there is a need for these oils. According to API recommendations, any upstream effective class of category “S” replaces the downstream effective class. For diesel oils, the higher class in effect usually, but not always, replaces the lower class.

API Specification for Gasoline Engines

API Specification for Diesel Engines

Marking

ILSAC classification developed by the International Committee for Approval and Standardization lubricants (ILSAC) in partnership with JAMA (Japan Automobile Manufacturers Association) and AAMA (American Automobile Manufacturers Association). For gasoline engines of Japanese-made passenger cars, this classification is best suited, for american cars both oils according to ILSAC and API are equivalent. The current ILSAC standard, adopted in 2004, is GF-4. Oils of this class are energy efficient, compatible with exhaust gas aftertreatment systems and provide improved engine wear protection. In 2010, the introduction of the GF-5 standard is expected.

Classification of engine oils by purpose and ACEA performance levels

The Association des Constracteuis Europeen des Automobiles (Association des Constracteuis Europeen des Automobiles) - since January 1, 1996, has introduced its own classification of engine oils, which has been repeatedly updated since then. Here is the classification introduced on December 22, 2008.

The requirements of European standards for the quality of motor oils are more stringent than American ones, because in Europe, the operating conditions and engine design differ from American ones:

• more high degree forcing and maximum speed;
• lower engine weight;
• higher power density;
• high permissible travel speeds;
• more severe urban regimes.

Due to these features, engine oil tests are carried out at european engines and by methods different from American ones. This does not allow direct comparisons of ACEA and API requirements and standards.

The ACEA classification divides engine oils into 3 classes:

• A / B - for gasoline engines and diesel engines of cars and light trucks;
• C - compatible with exhaust gas converters;
• E - for powerful diesel engines trucks.

A / B- oils for gasoline and diesel engines

A1 / B1 Designed for gasoline and light duty diesel engines that are designed for extended drain oils that provide low friction, low viscosity at high temperatures and high shear rates (2.9 to 3.5 mPa.s.) These oils may not be suitable for service in some engines. It is necessary to follow the instruction manual of the car.

A3 / B3 Designed for high performance gasoline and light duty diesel engines designed for use and / or with extended drain intervals as recommended by the engine manufacturers and / or for use in difficult conditions operation, and / or all-season use of low-viscosity oils.

A3 / B4 Designed for use in high-performance gasoline engines and diesel engines with direct fuel injection. Can be used instead of A3 / B3 oils.

A5 / B5 Designed for high performance gasoline and light duty diesel engines that are designed for extended drain oils that provide low friction, low viscosity at high temperatures and high shear rates (2.9 to 3.5 mPa.s.) These oils may not be suitable for works in some engines. It is necessary to be guided by the vehicle operating instructions.

C - oils compatible with catalytic converters

C1 Designed for vehicles equipped particulate filters and three-way catalytic converters. They are used in high-performance gasoline engines and light diesel enginesrequiring oils that provide a low coefficient of friction, low viscosity, low sulphate ash, low sulfur and phosphorus content, having a minimum viscosity at high temperatures and high speeds shear 2.9 mPa.s.

C2 Designed for vehicles equipped with particulate filters and three-way catalytic converters. They are used in high performance gasoline engines and light diesel engines designed to use oils that provide a low coefficient of friction, low viscosity, having a minimum viscosity at high temperatures and high shear rates of 2.9 mPa.s.

These oils extend the life of particulate filters and catalytic converters and contribute to fuel economy. May not be suitable for some engines. It is necessary to be guided by the vehicle operating instructions.

C3 Designed for vehicles equipped with particulate filters and three-way catalytic converters. They are used in high-performance gasoline engines and light diesel engines with a minimum viscosity at high temperatures and high shear rates of 3.5 mPa.s.

C4 Designed for vehicles equipped with particulate filters and three-way catalytic converters. They are used in high-performance gasoline engines and light diesel engines requiring oils with low sulphated ash, low sulfur and phosphorus content, with a minimum viscosity at high temperatures and high shear rates of 3.5mPa.s.

These oils extend the life of particulate filters and catalytic converters. May not be suitable for some engines. It is necessary to be guided by the vehicle operating instructions.

E- for powerful diesel engines of trucks

E4

They can only be used in engines without a particulate filter, and in some engines with exhaust gas recirculation and nitrogen oxide reduction systems. However, manufacturer's recommendations may differ, so it is necessary
follow the vehicle operating instructions.

E6 Oils that provide high piston cleanliness, wear protection, high resistance to soot contamination and stable properties throughout the entire period of operation. Recommended for modern diesel enginesthat meet the requirements of Euro-1, Euro-2, Euro-3, Euro-4 and Euro-5 and operate in very difficult conditions with significantly extended drain intervals (in accordance with the manufacturer's recommendations).

They can be used in engines with an exhaust gas recirculation system, with or without a particulate filter, and in engines with nitrogen oxide reduction systems. Oils of this class are highly recommended for engines equipped with
Diesel particulate filters for low-sulfur fuels. However, manufacturer's recommendations may differ.
therefore it is necessary to follow the vehicle's operating instructions.

E7

extended drain intervals (in accordance with the manufacturer's recommendations). Recommended for use in engines without diesel particulate filters and for most engines equipped with exhaust gas recirculation and nitrogen oxide emission reduction systems. However, the manufacturer's recommendations may differ, therefore, the vehicle's operating instructions must be followed.

E9 Oils that effectively provide piston cleanliness and paint protection. Provides excellent wear protection, high resistance to soot contamination and stable properties throughout the entire service life.

Recommended for modern diesel engines meeting the requirements of Euro-1, Euro-2, Euro-3, Euro-4 and Euro-5 and working in severe conditions with
extended drain intervals (in accordance with the manufacturer's recommendations). They can be used in engines with or without particulate filters and in most engines equipped with exhaust gas recirculation and nitrogen oxide reduction systems.

Oils of this class are highly recommended for engines equipped with diesel particulate filters and designed to operate on fuels with a low sulfur content. However, the manufacturer's recommendations may differ, therefore, the vehicle's operating instructions must be followed.

Classification of engine oils by viscosity, purpose and levels of performance GOST

According to GOST 17479.1-85, the marking of oils includes the following signs:

• letter M (motor)
• one or two numbers, separated by a fraction, indicating the grade or grades of viscosity (for multigrade oils). For multigrade oils, the numerator characterizes the winter class, and the denominator characterizes the summer class; the letter "z" indicates that the oil is thickened, ie contains a thickening (viscous) additive.
• one or two letters (from A to E) indicating the level of performance and scope of this oil. Universal oils are designated by a letter without an index or by two different letters with different indexes. Index 1 is assigned to oils for gasoline engines, index 2 is assigned to diesel oils.

For example, the M-6z / 10V brand indicates that this is an all-season engine oil, universal for medium-powered diesel engines and gasoline engines (group B). M-4z / 8-B2G1 is an all-season, universal motor oil for medium-powered diesel engines (group B2) and highly-powered gasoline engines (group G1).

Car manufacturers specifications

The API and ACEA classifications formulate the minimum basic requirements, which are agreed between the manufacturers of oils, additives to them and the car manufacturers. The latter have the right to put forward their own additional requirements for oils, which are formulated in the specifications of automobile plants. Since engine designs different brands differ from each other, the operating conditions of the oil in them are not quite the same. Therefore, car manufacturers test oils on their own engines. Based on this, either a certain class is indicated according to some generally accepted classification, or they make their own specifications, which indicate specific brands of oils approved for use. The manufacturer's specifications must be present in the vehicle operating instructions, and their number is applied to the oil packaging next to the designation of its performance class.

The API (American Petroleum Institute) engine oil classification system was established in 1969. According to the API system, three operational categories (three rows) of the purpose and quality of engine oils are established:

S (Service) - consists of quality categories of motor oils for gasoline engines, in chronological order.
C (Commercial) - consists of the categories of quality and purpose of oils for diesel engines, in chronological order.
EC (Energy Conserving) - energy saving oils. New row high-quality oils, consisting of low-viscosity, low-flowing oils that reduce fuel consumption in gasoline engine tests.

For each new class, an additional letter is assigned alphabetically. Multipurpose oils for gasoline and diesel engines are indicated by two symbols of the respective categories: the first symbol is the main one, and the second indicates the possibility of using this oil for a different type of engine. Example: API SM / CF.

API quality classes for gasoline engines

API SN class - approved on October 1, 2010.
The main difference between API SN and previous API classifications is in limiting the phosphorus content for compatibility with modern exhaust gas aftertreatment systems, as well as comprehensive energy savings. That is, oils classified by API SN will approximately correspond to ACEA C2, C3, C4, without correction for high-temperature viscosity.

API SM class - approved on November 30, 2004.
Motor oils for modern gasoline (multivalve, turbocharged) engines. Compared to the SL class, engine oils that meet API SM requirements must have better protection against oxidation and premature wear of engine parts. In addition, standards have been raised regarding oil properties when low temperatures... Engine oils of this class can be certified according to the ILSAC energy efficiency class
Engine oils that meet the requirements of API SL, SM can be used in cases where the car manufacturer recommends class SJ or earlier.

API SL class - motor oils for engines of cars manufactured after 2000.
In accordance with the requirements of car manufacturers, motor oils of this class are used in multivalve, turbocharged engines operating on lean fuel mixtures that meet modern increased environmental requirements, as well as energy saving. Automotive oils that meet API SL requirements can be used in cases where the car manufacturer recommends the SJ class or earlier.

SJ API class - engine oils for use in gasoline engines since 1996 release.
This class describes motor oils that are used in gasoline engines since 1996. Motor oils of this class are intended for use in gasoline engines of cars and sports cars, minibuses and light truckswhich are serviced according to the requirements of the car manufacturers. SJ provides the same minimum standards as SH, plus additional carbon and low temperature requirements. Engine oils meeting API SJ requirements can be used when the vehicle manufacturer recommends SH class or earlier.

API SH class- motor oils for gasoline engines since 1994.
The class was adopted in 1992 for engine oils recommended since 1993. This class is characterized by higher requirements compared to the class SG, and was developed as a substitute for the latter, to improve the anti-carbon, antioxidant, anti-wear properties of oils and increased protection against corrosion. Motor oils of this class are intended for use in gasoline engines passenger cars, vans and light trucks, in accordance with the recommendations of their manufacturers. Engine oils of this class have been tested in accordance with the requirements of the Chemical Manufacturers Association (CMA). Engine oils of this class can be used when the vehicle manufacturer recommends class SG or earlier.

API SG class- motor oils for gasoline engines since 1989.
Designed for use in gasoline engines of passenger cars, minibuses and light trucks. Motor oils of this class have properties that provide improved protection against carbon deposits, engine oil oxidation and engine wear, in comparison with previous classes, and also contain additives that protect against rust and corrosion of internal engine parts. SG engine oils meet API CC diesel engine oils and can be used where SF, SE, SF / CC, or SE / CC grades are recommended.

API SF class- motor oils for gasoline engines since 1980 (obsolete class).
These engine oils were used in gasoline engines from 1980-1989, subject to the recommendations and instructions of the engine manufacturer. Provides enhanced oxidation stability, improved wear protection compared to baseline SE lubricants, and better protection against carbon deposits, rust and corrosion. Engine oils of class SF could be used as replacements for previous classes SE, SD or SC.

API SE class - motor oils of gasoline engines produced since 1972 (obsolete class). These engine oils were used in gasoline engines produced in 1972-79, as well as some models in 1971. Additional protection in comparison with SC and SD motor oils and can be used as substitutes for these categories.

API SD class - motor oils for use in gasoline engines since 1968 (obsolete class). Motor oils of this class were used in gasoline engines of passenger cars and some trucks produced in 1968-70, as well as some models of 1971 and later. The improved protection compared to SC engine oils was also used only when recommended by the engine manufacturer.

API SC class - motor oils for gasoline engines, since 1964 (obsolete class). They were usually used in engines of passenger cars and some trucks produced in 1964-1967. Reduces high and low temperature carbon deposits, wear, and also protects against corrosion.

API SB class - motor oils for low-power gasoline engines (obsolete class). Motor oils of the 30s of the 20th century, which provided fairly light protection against wear and oxidation, as well as anti-corrosion protection for bearings in motors that are operated under light load conditions. Engine oils of this class may only be used if specifically recommended by the engine manufacturer.

API SA Class - motor oils for gasoline and diesel engines. An outdated class of oils for use in old engines operating in conditions and modes in which protection of parts with additives is not needed. Engine oils of this class can only be used if they are recommended by the engine manufacturer.

API Grades for Diesel Engines

API class CJ-4- valid from October 1, 2006.
This class is specially designed for heavy duty engines. Meets key NOx and particulate emissions regulations for 2007 engines. For CJ-4 oils, limits are introduced for some indicators: ash content less than 1.0%, sulfur 0.4%, phosphorus 0.12%.
The new classification accommodates the requirements of the earlier API categories CI-4 PLUS, CI-4, but introduces significant changes to the requirements in response to the needs of new engines that meet the new 2007 and later emission standards.

API Class CI-4 (CI-4 PLUS) - a new performance class of engine oils for diesel engines. Compared to API CI-4, the requirements for the specific soot content as well as volatility and high-temperature oxidation are increased. When certified in this classification, the engine oil must be tested in seventeen motor tests.

API Class CI-4 - the class was introduced in 2002.
These engine oils are used in modern diesel engines with different kinds injection and boost. An engine oil corresponding to this class must contain the appropriate detergent and dispersant additives and, in comparison with the CH-4 class, has increased resistance to thermal oxidation, as well as higher dispersing properties. In addition, such motor oils provide a significant reduction in engine oil waste by reducing volatility and reducing evaporation when operating temperature up to 370 ° C, under the influence of gases. The requirements for cold pumpability have also been strengthened, the resource of clearances, tolerances and engine seals has been increased by improving the fluidity of the motor oil.
The API CI-4 class was introduced due to the emergence of new, more stringent requirements for the ecology and toxicity of exhaust gases, which are imposed on engines manufactured from October 1, 2002.

API class CH-4 - valid from December 1, 1998.
Motor oils of this class are used in four-stroke diesel engines that operate in high-speed modes and meet the requirements of the norms and standards for exhaust gas toxicity adopted in 1998.
API CH-4 motor oils meet the stringent requirements of both American and European diesel engine manufacturers. The class requirements are specially designed for use in motors running on high quality fuels with a sulfur content of up to 0.5%. Moreover, unlike aPI class CG-4, the resource of these engine oils is less sensitive to the use of diesel fuel with a sulfur content of more than 0.5%, which is especially important for countries South America, Asia, Africa.
API CH-4 engine oils meet increased requirements and must contain additives that more effectively prevent valve wear and the formation of carbon deposits on the internal surfaces. They can be used as replacements for API CD, API CE, API CF-4 and API CG-4 engine oils in accordance with the engine manufacturer's recommendations.

API Class CG-4- class presented in 1995.
Motor oils of this class are recommended for four-stroke diesel engines of buses, trucks and tractors of mainline and non-mainline types, which are operated under increased loads, as well as high-speed modes. API CG-4 engine oil is suitable for engines that use high-quality fuels with a specific sulfur content of no more than 0.05%, as well as for engines for which there are no special requirements for fuel quality (specific sulfur content can reach 0.5% ).
Automotive oils certified according to the API CG-4 class should more effectively prevent wear of internal engine parts, the formation of carbon deposits on internal surfaces and pistons, oxidation, foaming, the formation of soot (these properties are especially needed for modern engines main buses and tractors).
API CG-4 class was created in connection with the approval in the United States of new requirements and standards for the ecology and toxicity of exhaust gases (1994 revision). Motor oils of this class can be used in engines for which API CD, API CE and API CF-4 classes are recommended. The main drawback limiting the massive use of this class of motor oils, for example, in Eastern Europe and Asia, is the significant dependence of the motor oil resource on the quality of the fuel used.

API class CF-2 (CF-II) - motor oils intended for use in two-stroke diesel enginesthat are operated in difficult conditions.
The class was introduced in 1994. Motor oils of this class are commonly used in two-stroke diesel engines that operate under high stress conditions. API CF-2 oils must contain additives that provide enhanced performance protection against wear on internal engine parts such as cylinders and rings. In addition, these motor oils should prevent the accumulation of deposits on the internal surfaces of the engine (improved cleaning function).
An API CF-2 certified engine oil has improved properties and can be used in place of earlier comparable oils, subject to the manufacturer's recommendation.

API class CF-4 - engine oils for use in four-stroke diesel engines since 1990.
Motor oils of this class can be used in four-stroke diesel engines, the operating conditions of which are associated with high-speed modes. For such conditions, the requirements for the quality of oils exceed the capabilities of the CE class, therefore CF-4 engine oils can be used instead of CE oils (subject to the appropriate recommendations of the engine manufacturer).
API CF-4 motor oils must contain appropriate additives that reduce car oil waste, as well as protection against carbon deposits in the piston group. The main purpose of motor oils of this class is the use in diesel engines of heavy-duty tractors and other vehicles that are used for long-distance trips on highways.
In addition, these engine oils are sometimes assigned the API CF-4 / S dual grade. In this case, subject to the availability of appropriate recommendations from the engine manufacturer, these oils can also be used in gasoline engines.

API CF class (CF-2, CF-4) - motor oils for diesel engines with indirect injection. Classes were introduced from 1990 to 1994. A hyphenated number means a two- or four-stroke engine.
Class CF describes engine oils recommended for use in diesel engines with indirect injection, as well as other types of diesel engines that run on fuels of various qualities, including those with a high sulfur content (for example, more than 0.5% of the total weight).
CF engine oils contain additives to better prevent piston deposits, wear and corrosion of copper (copper) bearings, which are important for these types of engines, and can be pumped in the usual way as well as with a turbocharger or compressor. Engine oils of this class can be used where the CD quality class is recommended.

CE API class - motor oils for use in diesel engines from 1983 (obsolete class).
Motor oils of this class were intended for use in some heavy-duty turbocharged engines, characterized by a significantly increased working compression. The use of such oils was allowed for engines with both low and high shaft speeds.
API CE engine oils have been recommended for low and high speed diesel engines manufactured since 1983 that have been operated under high load conditions. Subject to the availability of appropriate recommendations from the engine manufacturer, these oils could also be used in engines for which CD class engine oils were recommended.

API class CD-II - motor oils for use in heavy-duty diesel engines with a two-stroke operating cycle (obsolete class).
The class was introduced in 1985 for use in two-stroke diesel engines and is, in fact, an evolutionary development of the previous API CD class. The main purpose of the use of such auto oils was the use in heavy powerful diesel engines, which were installed mainly on agricultural machinery. Motor oils of this class meet all working standards of the previous CD class, in addition, the requirements for highly effective engine protection against carbon deposits and wear are significantly increased.

API CD class - motor oils for diesel engines of increased power, which were used in agricultural machinery (obsolete class). The class was introduced in 1955 for normal use in some diesel engines, both naturally aspirated and turbocharged, with increased cylinder compression, where effective protection against soot and wear is essential. Engine oils of this class could be used in cases where the engine manufacturer did not put forward additional requirements for the quality of the fuel (including fuels with a high sulfur content).
API CD motor oils were supposed to provide increased protection against corrosion of bearings and high-temperature carbon deposits in diesel engines, in comparison with previous classes. Engine oils in this class are often referred to as "Caterpillar Series 3" due to their compliance with the Caterpillar Tractor Company Superior Lubricants (Series 3) certification.

API CC class - motor oils for diesel engines that are operated at medium load conditions (obsolete class).
The class was introduced in 1961 for use in some engines, both naturally aspirated and turbocharged, which were characterized by increased compression. Motor oils of this class were recommended for engines that were operated under moderate and high load.
In addition, subject to the availability of the engine manufacturer's recommendations, such oils could be used in some powerful gasoline engines.
Compared to earlier grades, API CC motor oils were required to provide a higher level of protection against high temperature carbon deposits and bearing corrosion in diesel engines, as well as rust, corrosion and low temperature carbon deposits in gasoline engines.

CB API class - motor oils for diesel engines operating with medium load (obsolete class).
The class was approved in 1949 as an evolutionary development of the CA class when using fuels with a high sulfur content without special quality requirements. API CB motor oils were also intended for use in supercharged engines that were operated in light and moderate conditions. This class was often referred to as "Appendix 1 Engine Oils", thereby emphasizing compliance with the military regulation MIL-L-2104A Appendix 1.

CA API class - motor oils for lightly loaded diesel engines (obsolete class).
Motor oils of this class are intended for use in diesel engines operating in light and moderate modes at high quality diesel fuel... In accordance with the recommendations of car manufacturers, they can also be used in some gasoline engines that are operated in moderate modes.
The class was widely used in the 40s and 50s of the last century and cannot be used in modern conditions, unless it is provided for by the requirements of the engine manufacturer.
API CA engine oils must have properties that provide protection against carbon deposits on piston rings, as well as against corrosion of bearings in supercharged engines, for which there are no special requirements for the quality of the fuel used.

Oil quality - this is a set of properties that is necessary for the oil to work as intended. To facilitate the selection of the required oil for a specific engine type and operating conditions, an API engine oil classification system has been created.

This classification was created and is being improved in collaboration with API (American Petroleum Institute), ASTM (American Society for Testing and Materials) and SAE. It determines the limits of various parameters (in particular, piston cleanliness, piston ring wear, etc.) using various test motors.

According to the API system, 2 operational categories of purpose and quality are established

1. For gasoline engines with classes SE, SF, SG, SH, SJ, SL, SM, SN.
2. For diesel engines with classes CC, CD, CE, CF, CG, CH, CI, CJ.

Universal oils for gasoline and diesel engines are indicated by two symbols of the respective categories: the first symbol is the main one, and the second indicates the possibility of using this oil for a different type of engine. For example, API CG-4 / SH is an oil optimized for use in diesel engines, but it can also be used in gasoline engines for which an API SH or lower oil is prescribed (SG, SF, SE, etc.).

Categories of oils for gasoline engines of passenger cars

Categories of oils for diesel engines of commercial vehicles

How long and efficiently, that is, economically, will it work car engine, largely depends on the engine oil used, its classification according to SAE, API or ACEA. This is especially true in winter, when the engine starts in frost, and it takes much longer to warm up the unit.

How to help the engine of your favorite car last longer? Every motorist secretly hopes that someone very smart will invent a fabulous elixir of eternal youth. A few drops of which will ensure that everything inside the engine sparkles clean and the exhaust smells of violets. IN real life the role of such an elixir is assigned to motor oil.

But its service life is insultingly small, since engine oil has to work in very difficult conditions, taking on the bulk of mechanical, temperature and aggressive chemical influences. It is no exaggeration to say that oil saves the engine at the cost of its life.

He gets especially bad from high temperatures. Suffice it to say that the temperature of the gases in the combustion chamber can reach 2500 degrees. It is also hot in the area of \u200b\u200bthe first piston groove, about 300 degrees. The temperature of gases escaping into the crankcase during the stroke is 150-450 degrees in gasoline engines and 500-700 degrees in diesel engines.

Information about the engine oil, as indicated by the label on the canister.

The first and often decisive purchase, information about the oil, the buyer receives from the label glued to the canister. Having understood the inscriptions and designations, you can quite confidently choose the right oil. And for an ultra-modern, electronically-stuffed injection engine, and for a long-established resource soviet car industry... The year of release of which was lost somewhere in the last century.

So, let's consider a specific label, abstracting from the manufacturer as much as possible and brand product. First information you need: Fully Synthetic Motor Oil indicates that the canister contains fully synthetic motor oil.

It will be appropriate to remind here that by origin, or depending on the type of base, lubricating oils are divided into mineral oils. Mineral, that is, petroleum raffinates obtained from heavy fractions of oil distillation products are used as the basis. And synthetic - their bases are prepared on the basis of synthetic hydrocarbons or petroleum hydrocracking products.

Synthetic oils, in contrast to mineral oils, have a better ability to maintain fluidity at low temperatures, minus 40-50 degrees and below, and at the same time withstand high operating temperatures without noticeable decomposition and evaporation. The intermediate group consists of the so-called semi-synthetic oils, which may include both mineral and synthetic substances.

Second required information: The designation 5W-40 indicates that the SAE - the Society of Automotive Engineers of the USA - has classified this oil as multigrade in the operating temperature range from minus 30 degrees to +35 degrees. SAE has been classifying oils by viscosity for decades, and no one questions the conclusions of this international expert.

The most common SAE grades are 0W, 5W, 10W, 15W, 20W, 25W (winter) and 20, 30,40, 50, 60 (summer). Combined, or all-season, oils have a double designation. For example 0W-40 or 15W-40. They must correspond in terms of low-temperature properties to the winter class W, and in terms of high-temperature properties to summer.

Third required information contained in the API SG / CD label. She informs that API - American Petroleum Institute divides motor oils into two main groups: S (Service) for gasoline engines and C (Commercial) for diesel engines. road transport, road construction machinery and agricultural machinery.

In turn, these groups of oils are divided into quality classes, which, in fact, constitute a certain set of performance properties for motor oils of each class. These classes are designated by letters of the Latin alphabet. Moreover, the farther the letter is from its beginning, that is, from A, the higher the quality indicators of the oil - for example, SF, SG, SJ, SM, CC, CE, CF, etc. Additional numbers in class designations, for example, CF-2 , CF-4, CG-4 ,. informs about the applicability of this oil for 2-stroke or 4-stroke diesel engines.

Oils that can be used to lubricate both gasoline and diesel engines are called universal oils. They are designated by double marking, for example, SJ / CF, SH / CF and the like. On the label, these classes are separated by an oblique line (API SJ / CF-4). The first is the class of oil that is more preferable for the given product. That is, in the above case, the main purpose of the car oil is for gasoline engines, but at the same time the manufacturer allows its full use in diesel engines.

On the canister labels of many engine oils from well-known manufacturers (and not only), you can also see the abbreviation ACEA and a code, for example: A3 / B4-04. This code ACEA - the Association of European Automobile Manufacturers - designates engine oils for modern European car engines. In the example shown, for engines with direct fuel injection.

ACEA also divides oils into classes: A - for gasoline engines, B - for diesel engines of passenger cars, C - compatible with exhaust gas converters. E - for diesel engines of trucks. In terms of performance, oils of the newest class C are equivalent to universal oils of category A3 / B5-04. C1-04 and C2-04 oils have low viscosity and improved energy saving properties.

Certification of oils for compliance with ACEA requirements is carried out based on the results of laboratory and motor tests. Mainly in European-made engines. Test methods for fuels and oils are standardized by the CEC (Coordinating European Council) - European Coordination Council. Strict control is established for strict observance of the rules for certification of oils.

The difference between the European and American systems for evaluating the performance properties of engine oils has developed historically. This is due to some difference in the design of the engines and their operating conditions.

The oil canister label may also contain an inscription confirming the approval of this oil for use in vehicles of the respective types and manufacturers. For example MB 229.1. This tolerance makes it possible to delve less into the classification of API and ACEA, but only requires the attention of the car owner, so that he does not forget to look into the operating manual of his vehicle.

Based on the materials of the automobile weekly "Autocentre". No. 44.2012.
Vladimir Yaroshenko.