Classification of motor oils for application conditions and performance levels by the American Petroleum Institute (API).

According to the API classification, engine oils are divided into two categories: "S" (Service) and "C" (Commercial).

S (Service)- consists of quality categories of motor oils for gasoline engines, going in chronological order. For each new generation, an additional letter is assigned alphabetically: API SA, API SB, API SC, API SD, API SE, API SF, API SG, API SH and API SJ (SI category - intentionally omitted by API, to avoid confusion with the International system measures).

The API SA, API SB, API SC, API SD, API SE, API SF, API SG categories are now invalidated as obsolete, however, in some countries, oils of these categories are still produced, the API SH category is "conditionally valid" and may be used only as an option, eg API CG-4/SH.

The SL class was introduced in 2001 and differs from SJ in significantly better antioxidant, antiwear, antifoam properties, as well as lower volatility.

C (Commercial)- consists of categories of quality and purpose of oils for diesel engines, going in chronological order. For each new generation, an additional alphabetical letter is assigned: API CA, API CB, API CC, API CD, API CD-II, API CE, API CF, API CF-2, API CF-4, API CG-4 and API CH -four.

Categories API CA, API CB, API CC, API CD, API CD-II are now invalidated as obsolete, but in some countries oils of these categories are still produced.

Classes of oils indicating the scope are designated by letters of the Latin alphabet in ascending order, following the category designation: "Service" (SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL,SM,SN), "Commercial" (CA, CB, CC, CD, CD+, CD-II, CE, CF-4, CF-2, CG-4, CH-4, CI-4). The numbers in the designations of the classes CDII, CF-4, CF-2, CG-4 provide additional information on the applicability of oils of this class in 2-stroke or 4-stroke engines. The introduction of each new class was due to the tightening of requirements for oils, in particular, caused by environmental legislation, the expansion of the use of turbocharged engines, exhaust gas recirculation.

To designate universal oils, i.e. those that can be used for the lubrication of gasoline and diesel engines, double marking is adopted, for example, SF / CC, CF-4 / SH, etc.

For gasoline engines - oil classes on the S scale
Oil group		Vehicle Years	Qualitative indicators
SM	Introduced in November 2004. Trends in the development of technology are aimed at improving their environmental safety, increasing maintenance intervals while maintaining reliability. Naturally, this makes its own adjustments to the process of improving engines, being reflected in the qualities of lubricants. Following these trends, in November 2004, a class for engine oils for gasoline engines appeared in the API classification - SM, suggesting, compared to SL, increased requirements for lubricants regarding oxidation resistance, protection against deposits, wear, etc. Since October 2006, the category for diesel oils of the CJ-4 class has been replenished.	since 2004	-
SL	(active). API planned to develop the PS-06 project as the next API SK category, but one motor oil supplier in Korea uses the abbreviation "SK" as part of its corporate name. To eliminate possible confusion, the letter "K" will be omitted for the next category "S". - stability of energy-saving properties; - reduced volatility; - Extended drain intervals.	since 2001	-
SJ	(active). The category was approved on 11/06/1995, licenses began to be issued from 10/15/1996. Automotive oils in this category are designed for all currently used gasoline engines and completely replace the oils of all previously existing categories in older engine models. The maximum level of operational properties. API SJ/EC Energy Saving Certification Possibility.	since 1996	-
SH	(Conditionally active). Licensed category approved in 1992. To date, the category is conditionally valid and can only be certified as an additional category to API C categories (for example, API AF-4 / SH). According to the requirements, it meets the ILSAC GF-1 category, but without mandatory energy saving. Automobile oils in this category are designed for gasoline engines of 1996 and older models. When carrying out certification for energy saving, depending on the degree of fuel economy, API SH / EC and API SH / ECII categories were assigned.	since 1993	higher for models from 1995 onwards
SG	Licensed category approved in 1988. The issuance of licenses ceased at the end of 1995. Automotive oils are designed for engines of 1993 and older models. Fuel - unleaded gasoline with oxygenates. Satisfies the requirements for automotive diesel engine oils of API CC and API CD categories. They have higher thermal and oxidation stability, improved anti-wear properties, reduced tendency to form deposits and sludge. API SG automotive oils replace API SF, SE, API SF/CC and API SE/CC oils.	1989-1993
SF	Automobile oils in this category are designed for engines of 1988 and older models. Fuel - leaded gasoline. They have more effective than the previous categories, antioxidant, antiwear, anticorrosion properties and have a lower tendency to form high and low temperature deposits and slag. API SF automotive oils replace API SC, API SD and API SE oils in older engines.	1981-1988
SE	High performance engines operating under severe conditions.	1972-1980	higher
SD	Medium boosted engines operating in difficult conditions.	1968-1971	average
SC	Engines operating with increased loads.	1964-1967	-
SB	Motors operating at moderate loads are used only at the request of the manufacturer.	-	-
SA	Engines operating in light conditions are used only at the request of the manufacturer.	-	-

For diesel engines - oil classes on scale C
Oil group	Recommended area of ​​application	Vehicle Years	Qualitative indicators
CJ-4	Introduced in 2006. For high-speed four-stroke engines designed to meet 2007 emission standards on main roads. CJ-4 oils allow the use of fuels with sulfur content up to 500 ppm (0.05% by weight). However, operation with fuels containing more than 15ppm (0.0015% by weight) sulfur may affect the performance of exhaust aftertreatment systems and/or oil change intervals. Oils with the CJ-4 specification exceed the performance properties of CI-4, CI-4 Plus, CH-4, CG-4, CF-4 and can be used in engines for which oils of these classes are recommended.	since 2006	-
CI-4	Introduced in 2002. For high-speed four-stroke engines designed to meet the 2002 exhaust emission regulations. CI-4 oils allow the use of fuels with a sulfur content of up to 0.5% by weight, and are also used in engines with an exhaust gas recirculation (EGR) system. Replaces CD, CE, CF-4, CG 4 and CH-4 oils.	since 2002	-
CH-4	Introduced in 1998. For high speed 4-stroke engines that meet U.S. emission regulations since 1998. CH-4 oils allow the use of fuels with a sulfur content of up to 0.5% by weight. Can be used instead of CD, CE, CF-4 and CG-4 oils.	since 1998	-
СG-4	Introduced in 1995. For high-speed diesel engines operating on fuel with a sulfur content of less than 0.5%. CG-4 oils for engines that comply with the exhaust gas toxicity requirements introduced in the USA since 1994. Replaces CD, CE and CF-4 oils.	since 1995	higher for models since 1995
CF-4	Introduced in 1990. For high-speed four-stroke diesel engines with and without turbocharging. Can be used instead of CD and CE oils.	since 1990	higher for four-stroke engines
CF-2	Introduced in 1994. Improved performance, used instead of CD-II for two-stroke engines.	since 1994	higher for two-stroke engines
CF	Introduced in 1994. Oils for off-road vehicles, engines with split injection, including those running on fuel with a sulfur content of 0.5% by weight and above. Replaces CD oils.	since 1994	-
CE	Highly boosted advanced high turbo engines operating under severe conditions can be used in place of CC and CD grade oils.	since 1987	higher
CD	Class of oils for high-speed turbocharged diesel engines with high specific power, operating at high speeds and at high pressures and requiring increased anti-wear properties and prevention of carbon deposits.	since 1955	average
CC	Highly boosted engines (including moderately supercharged) operating in difficult conditions.	since 1961	low
CB	Medium boosted naturally aspirated engines operating at high loads on sour fuel.	1949-1960	-
CA	Engines operating at moderate loads on low sulfur fuel.	1940-1950	-

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

This classification was created and is being developed in collaboration with API (American Petroleum Institute), ASTM (American Society for Testing and Materials) and SAE. It determines the limits of various parameters (particularly 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 where SE, SF, SG, SH, SJ, SL, SM, SN classes apply.
2. For diesel engines where CC, CD, CE, CF, CG, CH, CI, CJ classes apply.

Universal oils for gasoline and diesel engines are indicated by two symbols of the corresponding categories: the first symbol is the main one, and the second indicates the possibility of using this oil for another 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 oil of API SH and lower categories (SG, SF, SE, etc.) is prescribed.

Categories of oils for gasoline engines of passenger cars

Oil group		Vehicle Years
SN	Current	Engine oil in this category provides better protection against high temperature piston deposits, reduction of low temperature deposits (tar) and enhanced compatibility with sealing parts. The API SN Resource Conserving category combines API SN performance with improved fuel economy, turbocharger component protection, emission control compatibility, and additional engine protection when using ethanol-containing fuels up to E85. Thus, this category can be equated with ILSAC GF-5	Introduced in October 2010 for vehicles 2011 and older.
SM	Current	Introduced in November 2004.	For vehicles 2004 and older
SL	Current	API planned to develop the PS-06 project as the next API SK category, but one motor oil supplier in Korea uses the abbreviation “SK” as part of its corporate name. To eliminate possible confusion, the letter “K” will be omitted for the next category “S”. - stability of energy-saving properties; - reduced volatility; - extended replacement intervals;	For vehicles 2001 and older
SJ	Current	The category was approved on 11/06/1995, licenses began to be issued from 10/15/1996. Automotive oils in this category are designed for all currently used gasoline engines and completely replace the oils of all previously existing categories in older engine models. The maximum level of operational properties. API SJ/EC Energy Saving Certification Possibility.	since 1996
SH	obsolete	Licensed category approved in 1992. To date, the category is conditionally valid and can only be certified as an additional category to API C categories (for example, API AF-4 / SH). According to the requirements, it meets the ILSAC GF-1 category, but without mandatory energy saving. Automobile oils in this category are designed for gasoline engines of 1996 and older models. When carrying out certification for energy saving, depending on the degree of fuel economy, API SH / EC and API SH / ECII categories were assigned.	since 1993
SG	obsolete	Licensed category approved in 1988. The issuance of licenses ceased at the end of 1995. Automotive oils are designed for engines of 1993 and older models. Fuel - unleaded gasoline with oxygenates. Satisfies the requirements for automotive diesel engine oils of API CC and API CD categories. They have higher thermal and oxidation stability, improved anti-wear properties, reduced tendency to form deposits and sludge. API SG automotive oils replace API SF, SE, API SF/CC and API SE/CC oils.	1989-1993
SF	obsolete	Automobile oils in this category are designed for engines of 1988 and older models. Fuel - leaded gasoline. They have more effective than the previous categories, antioxidant, antiwear, anticorrosion properties and have a lower tendency to form high and low temperature deposits and slag. API SF automotive oils replace API SC, API SD and API SE oils in older engines.	1981-1988
SE	obsolete	Should not be used in gasoline engines of vehicles manufactured after 1979.	1972-1980
SD	obsolete	Should not be used in gasoline engines of vehicles manufactured after 1971. Use in more modern engines may result in poor performance or breakdowns.	1968-1971
SC	obsolete	Should not be used in gasoline engines of vehicles manufactured after 1967. Use in more modern engines may result in poor performance or breakdowns.	1964-1967
SB	obsolete	Should not be used in gasoline engines of vehicles manufactured after 1951. Use in more modern engines may result in poor performance or breakdowns.	-
SA	obsolete	Does not contain additives. Should not be used in gasoline engines of vehicles manufactured after 1930. Use in more modern engines may result in poor performance or breakdowns.	-

Categories of oils for diesel engines of commercial vehicles

Oil group
CJ-4	Current	Introduced in 2006. For high-speed four-stroke engines designed to meet 2007 emission standards on main roads. CJ-4 oils allow the use of fuels with sulfur content up to 500 ppm (0.05% by weight). However, operation with fuels containing more than 15ppm (0.0015% by weight) sulfur may affect the performance of exhaust aftertreatment systems and/or oil change intervals. CJ-4 oils are recommended for engines equipped with diesel particulate filters and other aftertreatment systems. Oils with the CJ-4 specification exceed the performance properties of CI-4, CI-4 Plus, CH-4, CG-4, CF-4 and can be used in engines for which oils of these classes are recommended.
CI-4	Current	Introduced in 2002. For high-speed four-stroke engines designed to meet the 2002 exhaust emission regulations. CI-4 oils allow the use of fuels with a sulfur content of up to 0.5% by weight, and are also used in engines with an exhaust gas recirculation (EGR) system. Replaces CD, CE, CF-4, CG 4 and CH-4 oils. In 2004, an additional API category, CI-4 PLUS, was introduced. The requirements for soot formation, deposits, viscosity indicators, and the limitation of the TBN value have been tightened.
CH-4	Current	Introduced in 1998. For high speed 4-stroke engines that meet U.S. emission regulations since 1998. CH-4 oils allow the use of fuels with a sulfur content of up to 0.5% by weight. Can be used instead of CD, CE, CF-4 and CG-4 oils.
СG-4	obsolete	Introduced in 1995. For high-speed diesel engines operating on fuel with a sulfur content of less than 0.5%. CG-4 oils for engines that comply with the exhaust gas toxicity requirements introduced in the USA since 1994. Replaces CD, CE and CF-4 oils.
CF-4	obsolete	Introduced in 1990. For high-speed four-stroke diesel engines with and without turbocharging. Can be used instead of CD and CE oils.
CF-2	obsolete	Introduced in 1994. Improved performance, used instead of CD-II for two-stroke engines
CF	obsolete	Introduced in 1994. For diesel engines with two-cavity combustion chambers (indirect injection) and others installed on off-highway vehicles, including engines that operate on fuel with a sulfur content of more than 0.5% by weight. Can be used instead of CD oils.
CE	obsolete	Introduced in 1985. For high speed naturally aspirated and supercharged 4-stroke engines. Can be used instead of CC and CD.
CD-II	obsolete	Introduced in 1985. For two stroke engines.
CD	obsolete	Introduced in 1955. For some naturally aspirated and supercharged engines.
CC	obsolete	Should not be used in diesel engines manufactured after 1990.
CB	obsolete	Should not be used in diesel engines manufactured after 1961.
SA	obsolete	Should not be used in diesel engines manufactured after 1959.

The API classification of engine oils was developed in 1969. It is quite widespread all over the world.

She labels products of well-known manufacturers, such as Castrol, Motul, Shell. The marking indicates the type of car engine into which it is possible to fill the oil fluid. Its decryption is quite simple. According to the classification of oils according to API, all lubricants are divided into:

• S - motor oils for gasoline engines;
• C - consumables for diesels;
• EC - energy-saving motor oils. They are of high quality, low viscosity, fluidity, and are able to reduce fuel costs.

Lubricants suitable for any motor are marked with a pair of symbols. The 1st character is considered the main one, the 2nd indicates that the oil product can be poured into a different type of engine. Example: API SM/CF oils.

Categories of oils for internal combustion engines on gasoline

The API classification includes the following classes of oil for internal combustion engines on gasoline:

1. SN - approved 01.10.2010. Contains a limited amount of phosphorus. Compatible with new emission neutralizing systems, energy saving.
2. SM - approved 11/30/2004. The API SM class is for gasoline engines produced today. Better than SL, protects against oxidation and early wear of motor parts. Almost does not change its own characteristics in low-temperature conditions.
3. SL. Optimal for cars made in the twenty-first century. According to the tolerances of automakers, this lubricant is used in multi-valve, turbocharged power units that operate on lean fuel. The oil is environmentally friendly, energy-saving.
4. SJ. Suitable for gasoline engines manufactured after 1996. Such a car oil is intended for use in cars, sports cars, minibuses, small trucks. When using it, a little soot is formed, the lubricant retains its properties in winter.
5. SH. Optimal for gasoline engines made after 1994. Good resistance to soot, oxidation, wear, corrosive attack. It can be poured into cars, minibuses, freight transport. The main thing is to comply with the manufacturer's tolerances. They are listed in the table in the operating manual.
6. SG. Suitable for cars manufactured no earlier than 1989. The additives contained in the motor oil protect the engine parts from corrosion and rusting.
7. SF. An obsolete category in the API engine oil specification. A lubricant related to it can be poured into internal combustion engines made after 1980.
8. SE. Suitable for engines released after 1972.
9. SD. Car oil for use in gasoline engines manufactured after 1968 (obsolete category). The oil was used in gasoline internal combustion engines of cars and trucks.
10. SC. Oily fluid for engines manufactured after 1964. It was usually used in the engines of passenger cars, trucks manufactured in 1964-1967.
11. SB. Lubricant for gasoline engines that have low power. Provided rather weak protection of motor bearings from wear, oxidation, corrosive effects. Such a car oil cannot be poured into a modern car (unless the opposite is stated in the operating manual).
12. SA. It differs from previous oils in that it can be used not only in gasoline, but also in diesel engines. A very outdated group of lubricants that are almost never used today. Previously, high-quality protection of motor parts through additives was not particularly required, so SA API oils were quite popular.

Brief description of API oils

Categories of oils for diesel engines

API diesel engine oil may fall into one of the following categories:

1. CJ-4. It was introduced on 01.10.2006. It was developed specifically for high load motors. The lubricant meets the basic requirements for the formation of carbon deposits and solid elements for power units manufactured in 2007. There are restrictions on certain characteristics: ash content should be less than one percent, sulfur concentration - less than four tenths of a percent, phosphorus - less than twelve hundredths of a percent. Oils in this API quality class have all the benefits of lubricants from other categories. They are also great for modern powertrains, comply with the introduced environmental standards.
2. CI-4PLUS. The lubricant forms little soot, evaporates weakly, and practically does not oxidize at high temperatures. Any oil certified in this API specification class will pass approximately 17 production tests.
3. CI-4. This class was introduced into the API specification fifteen years ago. Similar motor oils are used in today's diesel engines with different types of injection and boost. They contain in their composition special dispersing and detergent additives. Consumables are resistant to thermal oxidation, have good dispersing properties. They also significantly reduce the amount of smoke during operation. Volatility is reduced, evaporation begins when the temperature reaches three hundred and seventy degrees Celsius. The oil is very fluid, perfectly passes through the entire lubrication complex in severe frosts. This reduces the wear of the sealing elements of the power unit.
4. CH4. The class was introduced on 01.12.1998. Lubricants are used in four-stroke diesel engines operating in high speed mode. They meet all requirements for the content of toxic substances in the exhaust. These requirements were adopted nineteen years ago. Oily fluids belonging to this category are recommended to be poured into the motor by automakers from Europe and the United States of America. Lubricants are designed for use in engines that run on very high quality fuel containing no more than five tenths of a percent of sulfur. However, they can be poured at a sulfur concentration that exceeds the established limit. This is especially important for South American, Asian and African states. Consumables contain additives that protect valves well from wear and prevent the appearance of carbon deposits on motor parts.
5. CG-4. This API oil class was introduced twenty-two years ago. Petroleum products included in this category must be poured into four-stroke diesel engines (buses, trucks, tractors - vehicles operated under highly loaded conditions and at high speeds). The level of sulfur in the fuel must not exceed five hundredths of a percent. You can also fill this oil into power units for which there are no special requirements for fuel quality (sulfur concentration can reach up to five tenths of a percent). Lubricants that are certified in this class do not allow wear of motor parts, the appearance of carbon deposits in the piston system. The elements of the power unit are less oxidized, little foam and soot are formed (such characteristics are very significant for the engines of today's buses and tractors). The main disadvantage, which limits the mass use of such consumables, for example, in Eastern European and Asian countries, is that oils significantly depend on the quality of the fuel being poured.
6. CF-2. API CF 2 oils are intended for use in two-stroke diesel engines operating in difficult conditions. The class was introduced twenty-three years ago. Such motor oils are usually poured into highly loaded engines.
7. CF-4. This includes lubricants designed to be filled in four-stroke diesel engines manufactured after 1990. Unless the automaker indicates otherwise in the owner's manual, the oil can be used in gasoline internal combustion engines.
8. CE. Motor oils for use in diesel engines manufactured no earlier than 1983. They were used in very powerful turbo engines, which are characterized by a significantly increased working pressure compared to others.
9. CD. The class was introduced in 1955. Such oils were often used in agriculture (tractors, combines).
10. CC. This class appeared in 1961. This includes oil products that can be poured into medium-loaded engines.
11. CB. The class was adopted in 1949. It was an improved CA class.
12. ca. Lubricants were poured exclusively into lightly loaded diesel power units.

Categories of oils for transmissions

It is necessary to familiarize yourself with the classification of gear oils in order to be able to decipher the marking when choosing a lubricant for the transmission. By means of the designations on the canister, it is possible to understand what the performance of the product is, what additives and base oils it consists of.

1. GL-1. Designed for cone-spiral, worm and mechanical gearboxes (without synchronizers) installed in trucks and special equipment.
2. GL-2. Optimal for worm gearboxes that operate in low-speed and light-loaded mode. Usually used in tractor equipment.
3. GL-3. Suitable for cone-helical transmissions operating in medium conditions. Designed to lubricate spiral and other truck gearboxes. Do not pour into hypoid transmissions.
4. GL-4. Oils for hypoid transmissions operating in high speed/low torque/low speed/high torque applications. Today, these lubricants are often used in synchronized gearboxes.
5. GL-5. Lubricants are suitable for hypoid gearboxes that operate under conditions of heavy load on the gear teeth and high speeds. Usually they are poured into transmissions with offset axles. For synchronized manual transmissions, you must use petroleum products approved by the automaker.
6. GL-6. Car oils are intended for filling in hypoid gearboxes with a large displacement. Today they are not used due to their complete displacement by GL-5 oils.

Purchasing lubricants,

pay attention to the declared specifications and

container tolerances.

Example

SAE 5W-20

ACEA A5/B5

API SN/SM, SL/CF, CF-2

ILSAC GF-5/C-3

GM-LL-A-025/GM-LL-B-025

VW 502.00/505.00, MB 229.31

BMW Longlife-04

Viscosity classification according toSAE

SAE- The American Society of Automotive Engineers assigns oils a viscosity grade according to a scale they developed. The most common all-weather oils with a double index, for example SAE0 W-30, 0 W-40, 5 W-30, 5 W-40 and others. The smaller value on the left with the abbreviation W , the higher the fluidity property of the oil at low temperatures. The larger value on the right without abbreviation W, the higher the viscosity of the oil at high temperatures. An oil change is carried out taking into account not only its type specified by the car manufacturer, but also the ambient temperature, the conditions of its use and other factors. For example: 5 W-30 (motor oil), 85W-90 (gear oil).

ViscositySAEand ambient temperature required at the time of engine start

Engine oil Transmission oil

When choosing the viscosity of engine oil, you should be guided by the recommendations of the manufacturer of a particular engine. These recommendations are based on the design features of the engine - the degree of oil loads, the hydrodynamic resistance of the oil system, the performance of the oil pump, the maximum oil temperatures in various areas of the engine depending on the ambient temperature, the engine is equipped with a catalytic diesel particulate filter (CDPF)

Purpose and quality

The quality of the oil is a set of properties that is necessary for the performance of the oil for its intended purpose. Some properties, such as viscosity, are essential for all oils, regardless of their purpose, while others are necessary only under certain conditions of use and in each case are characterized by separate quality indicators.

To facilitate the selection of oils of the required quality for a particular type of engine and operating conditions, classification systems have been created. Within each system, motor oils are divided into ranks and categories based on quality level and purpose. These series and categories were created at the initiative of international organizations of oil refineries and car manufacturers, taking into account the design features of various types of engines and their operating conditions. Purpose and quality levels are the basis of the range of oils. Due to differences in designs and operating conditions, there are currently several classification systems for motor oils at the same time - API/ ILSAC , JASO, ACEAand GOST (for CIS countries).

The US military department and the largest car manufacturers put forward additional requirements for the quality of motor oils. Thus, along with generally accepted classification systems, there are also requirements (specifications) of car manufacturers.

Classification systemAPI

API- The American Petroleum Institute, which assigns quality classes to oils according to their tests. The quality class is indicated on the label with two letters for gasoline engines ( SM, SN), letters and numbers for diesel engines ( CI-4 Plus, CJ-4 ). The higher the alphabetical order of the second letter in the designation, the higher the oil class. Besides, API assigns oils with viscosity 0 W-30, 5 W-30, 5 W-20 energy saving index, for example ILSACCF-5.

● APIS consists of quality categories of motor oils for gasoline engines, going in chronological order. For each new generation, an additional letter is assigned alphabetically : APISA, APISB, APISC, APISD, APISE, APISF, APISG, APISH, APISJ, APISM and APISN. Categories API SA , API SB, APISC, APISD, APISE, APISF, APISG, APISJ today invalidated as obsolete, however, in some countries, oils of these categories are still produced, category APISH is "conditional" and can only be used as an additional, for example APICG-4/ SH;

API STANDARD FOR GASOLINE ENGINE OIL
CATEGORY	STATUS	DESCRIPTION
SN	CURRENT	Introduced in October 2010 for vehicles 2011 and older. Engine oil in this category provides better protection against high temperature piston deposits, reduction of low temperature deposits (tar) and enhanced compatibility with sealing parts. The API SN Resource Conserving category combines API SN performance with improved fuel economy, turbocharger component protection, emission control compatibility, and additional engine protection when using ethanol-containing fuels up to E85. Thus, this category can be equated with ILSAC GF-5.
SM	CURRENT	For vehicles 2010 and older.
SL	CURRENT	For vehicles 2004 and older.
SJ	CURRENT	For vehicles 2001 and older.
SH	OBSOLETE
SG	OBSOLETE
SF	OBSOLETE
SE	OBSOLETE	ATTENTION! Should not be used in gasoline engines of vehicles manufactured after 1979.
SD	OBSOLETE	ATTENTION! Should not be used in gasoline engines of vehicles manufactured after 1971. Use in more modern engines may result in poor performance or breakdowns.
SC	OBSOLETE	ATTENTION! Should not be used in gasoline engines of vehicles manufactured after 1967. Use in more modern engines may result in poor performance or breakdowns.
SB	OBSOLETE	ATTENTION! Should not be used in gasoline engines of vehicles manufactured after 1951. Use in more modern engines may result in poor performance or breakdowns.
SA	OBSOLETE	ATTENTION! Does not contain additives. Should not be used in gasoline engines of vehicles manufactured after 1930. Use in more modern engines may result in poor performance or breakdowns.

● APIFROM consists of categories of quality and purpose of oils for diesel engines, going in chronological order. For each new generation, an additional letter is assigned alphabetically : APICA, APICB, APICC, APICD, APICE, APISF, APICF-2, APICF-4, APICG-4, APICI-4 and APICJ-4. Categories APICA, APICB, APICC, APICD today invalidated as obsolete, however, in some countries, oils of these categories are still produced;

API STANDARD FOR DIESEL ENGINE OIL
CATEGORY	STATUS	DESCRIPTION
CJ-4	CURRENT	For high speed 4-stroke diesel engines from 2010 model year on-road and Tier 4 off-highway emission standards and legacy diesel engines. Oils in this category are designed for use in engines designed to use diesel fuel with a sulfur content up to 500 ppm (0.05% by weight). However, when using fuel with a sulfur content greater than 15 ppm (0.0015% by mass), the life of the aftertreatment system and the oil change interval may be reduced. CJ-4 oils are particularly effective in maintaining the longevity of the emission control system of diesel engines that use diesel particulate filters and other advanced aftertreatment systems. Provides optimum protection against catalytic converter fouling, diesel particulate filter fouling, engine wear, piston deposits, soot and oxidative thickening, viscosity loss due to shear and foaming, as well as low and high temperature stability. API CJ-4 oil outperforms API CI-4 (including CI-4 PLUS), CI-4, CH-4, CG-4 and CF-4 oils and can serve as a full replacement. When using CJ-4 oil in combination with fuel containing more than 15 ppm sulfur, check with the engine manufacturer for oil change intervals.
CI-4	CURRENT	Introduced in 2002. For high-speed four-stroke engines meeting 2002 emission standards. CI-4 is designed to support the longevity of Exhaust Gas Recirculation (EGR) engines and is designed for use with diesel fuels containing less than 0.5% sulfur by weight. Can be used instead of CD, CE, CF-4, CG-4 and CH-4 oils. Due to their performance properties, some CI-4 oils may qualify for the CI-4 PLUS category.
CH-4	CURRENT	Introduced in 1998. For high speed four-stroke engines meeting 1998 emission standards. The CH-4 oil is designed for use with diesel fuel with a sulfur content not exceeding 0.5% by weight. Can be used instead of CD, CE, CF-4 and CG-4 oils.
CG-4	OBSOLETE	Introduced in 1995. For highly loaded, high-speed four-stroke engines operating on fuel with a sulfur content of not more than 0.5% by weight. CG-4 oil is required for engines that meet 1994 emission standards. Can be used instead of CD, CE and CF-4 oils.
CF-4	OBSOLETE	Introduced in 1990. For high speed naturally aspirated and supercharged 4-stroke engines. Can be used instead of CD and CE oils.
CF-2	OBSOLETE	Introduced in 1994. For highly loaded two-stroke engines. Can be used instead of CD-II oils.
CF	OBSOLETE	Introduced in 1994. For diesel engines with two-cavity combustion chambers (indirect injection) and others installed on off-highway vehicles, including engines that operate on fuel with a sulfur content of more than 0.5% by weight. Can be used instead of CD oils.
CE	OBSOLETE	Introduced in 1985. For high speed naturally aspirated and supercharged 4-stroke engines. Can be used instead of CC and CD.
CD-II	OBSOLETE	Introduced in 1985. For two stroke engines.
CD	OBSOLETE	Introduced in 1955. For some naturally aspirated and supercharged engines.
CC	OBSOLETE	ATTENTION! Should not be used in diesel engines manufactured after 1990.
CB	OBSOLETE	ATTENTION! Should not be used in diesel engines manufactured after 1961.
CA	OBSOLETE	ATTENTION! Should not be used in diesel engines manufactured after 1959.

● APIEFROM (ILSAC) - energy-saving oils (Resource Conserving). A new range of high quality oils consisting of low viscosity, easy flowing oils that reduce fuel consumption as tested in gasoline engines.

A decrease in oil viscosity can provide fuel economy in a warm engine of 0.6-5.5% (with a decrease in high-temperature viscosity), and in a cold one - 1.0-6.5% (with a decrease in low-temperature viscosity). With an optimal combination of engine and transmission oil, fuel savings of 2.7-10.9% can be achieved. The latest categories of oils certified by API, in case of compliance with the requirements of ILSAC, are designated by the "API Certification Mark Symbol" (API Certification Mark), the so-called "Starburst" mark. This mark can only be awarded to energy-saving, highly volatile oils of the highest quality level, with viscosity SAE 0W-.., 5W-.. and 10W-...

The ILSAC GF series oil requirements system is part of the American Oils Quality Assurance API (EOLCS). ILSAC GF-3 fuel economy tested meets API Class SM classification requirements; ILSAC class GF-4 complies with API classification class SM. For example: API SN fuel economy pass = ILSAC GF-5.

ILSAC STANDARD FOR PASSENGER CAR ENGINE OIL
EDITION	STATUS	DESCRIPTION
GF-5	CURRENT	Introduced in October 2010 for 2011 and older vehicles. GF-5 engine oil provides better protection against high-temperature deposits on engine pistons and turbocharger parts, reduction of low-temperature deposits (tar), improved fuel consumption, improved compatibility with the aftertreatment system, enhanced compatibility with sealing parts, as well as additional engine protection during using fuels containing ethanol up to grade E85.
GF-4	OBSOLETE	Valid until September 30, 2011. Use GF-5 oil instead of GF-4.
GF-3	OBSOLETE	Use GF-5 oil instead of GF-3.
GF-2	OBSOLETE	Use GF-5 oil instead of GF-2.
GF-1	OBSOLETE	Use GF-5 oil instead of GF-1.

Universal oils for gasoline and diesel engines are indicated by two symbols of the corresponding categories: the first is the main one, and the second indicates the possibility of using this oil for other types of engines. 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 oil of API SH and lower categories (SG, SF, SE, etc.) is prescribed.

Attention: each of the subsequent quality standards is superior to the previous one, so the latest quality standards are superior to all previous ones. For example, SN grade oils can be used instead of all grades for gasoline engines.

SignsAPI

Oils that meet the requirements of the current quality categories and have passed official API-SAE tests have on their labels a graphic round sign (donut mark) - “API service symbol” (API Service Symbol), which indicates the degree of viscosity according to SAE, quality category and API assignments and possible energy savings.

ACEA- European Association of Automobile Manufacturers. If these letters are present on the label, then the oil is suitable for use in European car engines. Classes ACEA also divided into diesel and gasoline.

AUTO MANUFACTURERS PERMISSIONS - some car companies such as Porsche, Mercedes- Benz, bmw, vw, Ford, impose additional requirements on oils for engine protection, fuel saving, extended service life, etc. You can find information about the tolerance required by you and the required intervals between oil changes in the service book of your car.

Probably, any motorist will agree that the key to durable and trouble-free operation of the engine is the use of high-quality motor oils, the characteristics of which would correspond to the maximum extent to the parameters set by the manufacturer. Given the fact that automotive oils operate in a wide range of temperatures and at high pressures, and are also exposed to aggressive environments, very serious requirements are placed on them. In order to streamline oils and facilitate the selection procedure for a particular type of engine, a number of international standards have been developed. Currently, the world's leading manufacturers use the following generally recognized engine oil classifications:

• SAE - Society of Automotive Engineers;
• API - American Petroleum Institute;
• ACEA - Association of European Automobile Manufacturers.
• ILSAC - International Committee for the Standardization and Approbation of Motor Oils.

Domestic oils are also certified according to GOST.

SAE engine oil classification

One of the main properties of motor oils is viscosity, which varies with temperature. The SAE classification separates all oils depending on their viscosity-temperature properties to the following classes:

• Winter - 0W, 5W, 10W, 15W, 20W, 25W;
• Summer - 20, 30, 40, 50, 60;
• All-weather oils are indicated by a double number, for example, 0W-30, 5W-40.

SAE class	Low temperature viscosity		High temperature viscosity
	cranking	Pumpability	Viscosity, mm 2 / s, at 100 ° С		Minimum viscosity, mPa*s, at 150 °С and shear rate 10 6 s -1
	Maximum viscosity, mPa*s
	6200 at -35 °C	60000 at -40 °C
	6600 at -30 °C	60000 at -35 °С
	7000 at -25 °С	60000 at -30 °C
	7000 at -20 °С	60000 at -25 °С
	9500 at -15 °C	60000 at -20 °С
	13000 at -10 °С	60000 at -15 °С
					3.5 (0W-40; 5W-40; 10W-40)
					3.7 (15W-40; 20W-40; 25W-40)

The main characteristic of winter oils is low temperature viscosity, which is determined by the indicators of cranking and pumpability. Maximum low temperature viscosity cranking measured according to the ASTM D5293 method on a CCS viscometer. This indicator corresponds to the values ​​​​at which the crankshaft speed required to start the engine is provided. Viscosity pumpability determined according to the ASTM D4684 method on the MRV viscometer. The pumpability temperature limit determines the minimum temperature at which the pump is able to supply oil to engine parts without allowing dry friction between them. Viscosity, which ensures the normal operation of the lubrication system, does not exceed 60,000 mPa * s.

For summer oils, minimum and maximum values ​​of kinematic viscosity at 100 °C, as well as indicators of minimum dynamic viscosity at a temperature of 150 °C and a shear rate of 10 6 s -1 are established.

All-weather oils must meet the requirements that are defined for the respective classes of winter and summer oils included in the designation.

API engine oil classification

The main indicators of oils in accordance with the API classification are: engine type and mode of operation, performance properties and conditions of use, year of manufacture. The standard provides for the division of oils into two categories:

• Category "S" (Service) - oils designed for 4-stroke gasoline engines;
• Category "C" (Commercial) - oils for diesel engines of vehicles, road construction equipment and agricultural machines.

The designation of the oil class includes two letters: the first is the category (S or C), the second is the level of performance.

The numbers in the designations (for example, CF-4, CF-2) give an idea of ​​the applicability of oils in 2 or 4-stroke engines.

If the engine oil can be used in both gasoline and diesel engines, then the designation consists of two parts. The first indicates the type of engine for which the oil is optimized, the second - another permitted engine type. An example designation is API SI-4/SL.

	Operating conditions
Category S
	Oils designed for gasoline engines of cars, vans and light trucks. The SH class provides for an improvement in the performance of the SG class, which it replaced.
	Ensures compliance with SH requirements and also introduces additional requirements for oil consumption, energy-saving properties and resistance to the formation of deposits when heated.
	It provides for the improvement of the antioxidant, energy-saving and detergent properties of oils.
	Establishes even more stringent requirements for engine oils.
	The standard applies additional requirements to ensure energy saving and wear resistance, and also implies a reduction in wear of rubber-technical products of the engine. API SN grade oils can be used in biofuel engines.
Category C
	It is used for oils used in high speed diesel engines.
	It is used for oils used in high speed diesel engines. Provides for the use of oils with a sulfur content in diesel fuel up to 0.5%. Provides an increase in the life of engines with an exhaust gas recirculation (EGR) system. There are additional requirements for antioxidant properties, wear resistance, deposit formation, foaming, degradation of sealing materials, shear loss of viscosity.
	It is used for oils used in high speed diesel engines. Provides the possibility of use when the sulfur content in diesel fuel is up to 0.05% by weight. CJ-4 oils work particularly well in engines with diesel particulate filters (DPF) and other exhaust aftertreatment systems. They also have improved antioxidant properties, stability over a wide temperature range, and resistance to deposit formation.

Classification of engine oils according to ACEA

The ACEA classification was developed by the Association of European Automobile Manufacturers in 1995. The latest edition of the standard provides for the division of oils into three categories and 12 classes:

• A/B - petrol and diesel engines of cars, vans, minibuses (A1/B1-12, A3/B3-12, A3/B4-12, A5/B5-12);
• C - gasoline and diesel engines with an exhaust gas catalyst (C1-12, C2-12, C3-12, C4-12);
• E - heavy duty diesel engines (E4-12, E6-12, E7-12, E9-12).

In the ACEA designation, in addition to the engine oil class, the year of its entry into force, as well as the edition number (if the technical requirements have been updated), are indicated.

Classification of motor oils according to GOST

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

• kinematic viscosity classes;
• performance groups.

By kinematic viscosity GOST 17479.1-85 subdivides oils into the following classes:

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

Viscosity classes of motor oils according to GOST 17479.1-85:

Viscosity class	Kinematic viscosity at 100 °C		Kinematic viscosity at -18 °С, mm 2 /s, no more

By Areas of use all motor oils are divided into six groups - A, B, C, D, D, E.

Motor oil groups according to performance properties according to GOST 17479.1-85:

Group of oils according to performance properties
		Unforced gasoline engines and diesel engines
		Lightly boosted gasoline engines operating in conditions that promote the formation of high temperature deposits and bearing corrosion
		Low boosted diesels
		Medium-boosted gasoline engines operating in conditions conducive to oil oxidation and the formation of all types of deposits
		Medium-boosted diesel engines with increased requirements for anti-corrosion, anti-wear properties of oils and a tendency to form high-temperature deposits
		Highly accelerated gasoline engines operating under severe operating conditions that contribute to oil oxidation, the formation of all types of deposits, corrosion and rust
		Highly boosted naturally aspirated or moderately aspirated diesel engines operating under operating conditions conducive to the formation of high temperature deposits
		Highly accelerated gasoline engines operating under operating conditions that are more severe than for oils of group G 1
		Highly accelerated supercharged diesel engines operating in severe operating conditions or when the fuel used requires the use of oils with high neutralizing ability, anti-corrosion and anti-wear properties, low tendency to form all types of deposits
		Highly accelerated gasoline and diesel engines operating under operating conditions that are more severe than for oils of groups D 1 and D 2. Differ in the increased dispersing ability, the best antiwear properties.

Index 1 indicates that the oil is intended for gasoline engines, index 2 for diesel engines. Universal oils do not have an index in the designation.

An example of engine oil designation:

M - 4 Z / 8 - V 2 D 1

M - engine oil, 4 Z / 8 - viscosity class, V 2 G 1 - can be used in medium-powered diesel engines (B 2) and high-powered gasoline engines (G 1).

Classification of motor oils according to ILSAC

The International Motor Oil Standards and Approval Committee (ILSAC) has issued five motor oil standards: ILSAC GF-1, ILSAC GF-2, ILSAC GF-3, ILSAC GF-4 and ILSAC GF-5.

	Year of introduction	Description
	outdated	Conforms to quality requirements of API SH classification; viscosity grades SAE 0W-XX, SAE 5W-XX, SAE 10W-XX; where XX is 30, 40, 50, 60
		Meets API SJ quality requirements, SAE 0W-20, 5W-20 are added to GF-1 classes
		Conforms to API SL classification. Differs from GF-2 and API SJ in significantly better antioxidant and antiwear properties, as well as improved volatility. ILSAC CF-3 and API SL classes are similar in many ways, but GF-3 oils are necessarily energy efficient.
		Complies with API SM classification with mandatory energy saving properties. SAE viscosity grades 0W-20, 5W-20, 0W-30, 5W-30 and 10W-30. It differs from the GF-3 category in higher oxidation resistance, improved detergent properties and less tendency to form deposits. In addition, oils must be compatible with exhaust gas catalysts.
		Meets API SM classification requirements with more stringent requirements for fuel economy, catalyst compatibility, volatility, detergency, and deposit resistance. New requirements are introduced for the protection of turbocharging systems against deposits and compatibility with elastomers.