Deciphering the oil classification according to API. Deciphering automotive oils according to the API standard What is the api classification

25.07.2019

September 18th, 2016 Admin

All car owners need to be able to understand motor oils, be able to read the information hidden in the markings written on the label. Right choice and use of the product good quality gives you a guarantee for a stable and long service life of the car engine. The properties of the lubricating product must meet all the conditions of the manufacturer. The operation of oils takes place under high pressure and in a large temperature range, for this reason such strict requirements are put forward to them.

To do easier process selection of oil for a certain type of engine according to necessary characteristics and the required conditions, several types of international standards have been developed. Global oil manufacturers use all recognized classifications.

Automobile classification engine oils:

ILSAC;
GOST;
ACEA.

Most often, 3 types of classification are used - API, GOST and ACEA.

There are 2 main categories of motor oils tied to the type of engine: diesel or gasoline. There is also a universal oil. The packaging must contain information on the purpose of the product. Every engine oil contains mineral oil, which is the main part of it, and required amount additives.

Lubricating fluid is divided by chemical composition into:

Synthetic.
Mineral.
Semi-synthetic.

On the container, next to other information, the chemical composition is always written.

What can be written on an oil canister:

API and ACEA additives present.
SAE density classification (viscosity).
Barcode.
Recommendations from car manufacturers.
Specialist. categories of motor oils.
Date of manufacture and lot number.
Pseudonymous labeling (has nothing to do with standard labeling, is part of marketing, for example, fully synthetic and the like).

To find out which oil is ideal for your car's engine, we will help you understand the more significant markings.

SAE engine oil classification: table

The main properties that are indicated in the markings on the container of the product are density parameters according to SAE classification- international standards, adjustable viscosity of oils depending on seasonal changes in air temperature.

Because of this, oils are divided into 3 types, which differ in their structure:

winter oils more liquid and allow you to easily start the car engine at low air temperatures. This type of SAE indicator is indicated by the symbol "W" (for example, 0W, 5W, 10W, and so on). In order to find out the limit value, the number 35 should be subtracted. At positive air temperatures, such an oil is not suitable for use, since it becomes too liquid in structure and cannot form a lubricating layer, i.e. will not fulfill its intended function.
summer oils are used at air temperatures from 0˚ and above, since their viscosity is quite high, so that when high temperature fluidity did not exceed desired indicator for efficient lubrication of engine parts. IN winter period year it will not be possible to start the engine with high viscosity oil. Are marked summer oils a numerical designation without letters (for example, 5,10,15, etc.; a larger number means a stronger viscosity).
Multigrade oils are the most popular because of the ability to carry out the functions of their destination both in the cold and in the warm season. The limit values \u200b\u200bof such oils can be viewed in the diagram, where they are deciphered SAE indicators. This type of oil is indicated by a double marking (for example, SAE 15W-40).

The viscosity characteristic is the very first and most significant component of the marking and specification of a lubricating fluid, but there are others. Making a choice of lubricating fluid using only viscosity data is wrong. It is also necessary to take into account the relationship between the properties of the product and the conditions of its use.

All oils have not only viscosity, but also many other different performance properties (anti-wear, detergent and antioxidant properties, corrosiveness, and others). These properties make it possible to determine the scope of their assignment.

API classification of motor oils: table

The main indicators in the classification according to API are: the type of engine and its mode of operation, the operating properties of the oil and the year of commissioning. Oils are divided according to the standard into 2 categories:

Category "S" - for engines running on gasoline.
Category "C" - designed for a diesel engine.

How to decipher the API engine oil label?

The API designation may begin with the letter "C" or "S". They indicate for which type of engine the oil is intended. The next letter defines the product class, which indicates the level of active properties.

According to this classification, the explanation of the marking of motor oils looks like this:

The abbreviated EU designation, located immediately after the API, indicates energy-saving oils.
Behind the abbreviation, indicating Roman numerals carry information about the level of fuel economy.
The letter "C" defines oils for engines running on diesel fuel.
The letter "S" denotes oils for gasoline engines.
Multipurpose oils are marked with letters of both categories through a slash (e.g. API SL/CF).
After the letters "S" or "C" indicate the degree of performance, it is indicated by letters from "A" (the smallest indicator) to "N", etc. (the higher in alphabetical order the value of the 2nd letter, the higher the product class).
For diesel engines oil API marking divided into two-stroke and four-stroke (indicated at the end by the number "2" or "4", respectively).

Engine oils that have passed a series of SAE/API checks and meet current grade quality standards are identified as a round symbol on labels. At the top of the sign is the designation - "API Service", in the central part - the degree of viscosity according to SAE, below - the degree of energy saving (if any).

Using motor oils of the required specification, you increase wear resistance and reduce the risk of engine breakdown. At the same time, fuel consumption and oil waste are reduced, the engine runs quieter, and its driving performance improves (especially at cold temperatures), the exhaust purification system and catalyst wear out less.

Classifications ILSAC, GOST, ACEA - what does it mean and how to decipher

Classification and designation of engine oils according to ILSAC

Joint development of America and Japan - ILSAC classification. The International Committee for Standardization and Testing has developed 5 lubricating fluid standards:

ILSAC GF-1,
ILSAC GF-2,
ILSAC GF-3,
ILSAC GF-4,
ILSAC GF-5.

They are similar to API grades and differ only in that the corresponding oils of the ILSAC classification are energy efficient and versatile in all seasons. Such a classification is the best option for Japanese cars.

Classification and designation of motor oils according to GOST

In accordance with GOST 17479.1-85, engine oils are divided into:

groups by active properties;
kinematic viscosity category.

By viscosity, oils are divided into the following classes:

Winter period of the year - 3, 4, 5, 6.
Summer period of the year - 6, 8, 10, 12, 14, 16, 20, 24.
Universal - 3/8, 4/6, 4/8, 4/10, 5/10, ... .6/16 (the 1st digit indicates the winter class, and the 2nd - summer).

The larger the numerical designation in all the classes described above, the higher the level of viscosity.

Engine oils are divided into 6 groups according to the area of \u200b\u200buse and are marked with letters from "A" to "E".

Oils with a digital indicator of "1" indicate their intended use in gasoline engines, "2" - for diesel engines, and the absence of a digital indicator indicates the versatility of the fluid.

Classification and designation of motor oils according to ACEA

Association of car manufacturers European countries developed the ASEA classification. It marks their categories and purpose, as well as operational properties oils for engines. This specification is also divided by application in gasoline and diesel engine types.

The latest standards divide oils into 3 varieties and 12 groups:

A / B - diesel and gasoline engines cars, minibuses and vans (A1/B1-12, A5/B5-12, etc.)
C - diesel and gasoline engines with a catalytic converter (C1-12 .... C4-12).
E - trucks with a diesel engine (E4-12 .... E9-12).

In addition to the classification of engine oil, the ACEA marking indicates the edition number (updates of technical requirements) and the year of commissioning. Domestic oils additionally undergo GOST certification.

Oil groups in the ILSAC category, their compliance with API standards:

ILSAC GF-1 (obsolete category) - oil quality similar to API SH classification; according to viscosity SAE 0W-20, 5W-35, 10W-40.
ILSAC GF-2 - similar in product quality to API SJ, in terms of density SAE 0W-20, 5W-25.
ILSAC GF-3 - corresponds to the API SL variety, entered service in 2001.
ILSAC GF-4 and ILSAC GF-5 are similar to SM and SN.

Also in accordance with ILSAC standard For Japanese cars with turbocharged diesel engines, the JASO DX-1 category has been developed. This oil marking is designed for engines of new cars with high environmental standards and built-in turbines.

Specifications and approvals of engine oils

The ACEA and API specifications express the minimum basic requirements adopted by additive and oil manufacturers and vehicle manufacturers. The characteristics of the oil during operation differ, because different brands Car engines are built differently. Some of the leading engine manufacturers have created their own personal oil classification method (simplified name - tolerance), which adds to the ACEA classification system. Engine manufacturers such as: BMW, Mercedes-Benz, Porsche, Renault, Ford, Fiat, GM - preferably use personal approvals when choosing engine oils.

Let's look at the more well-known and more commonly used tolerances that are indicated on the container of motor oils.

Engine oil approvals for VAG

Engine oil - VW 500.00 - energy saving (SAE 10W-30, 5W-30, 5W-40, etc.) For gasoline engines (up to year 2000), VW 501.01 is calculated - suitable for any seasonal period. VW 502.00 - intended for use in turbocharged engines.

Oil for engines running on gasoline with a viscosity of SAE 0W-30 - VW 503.00 - requiring a rarer change (up to 30,000 kilometers). For a car engine with an exhaust system with a three-way converter - VW 504.00.

The approval of VW 505.00 oils for TDI engines is provided for cars such as AUDI, VOLKSWAGEN, SKODA running on diesel (until 2000). PDE motors with a pump injector - oils with a VW 505.01 approval.

For vehicles running on diesel fuel (manufactured after 2002), an energy-saving oil with a viscosity of 0W-30 - VW 506.00 is recommended - more rarely requires replacement (up to 50,000 kilometers in 4-cylinder TDI engines). For engines running on diesel fuel with a pump-injector and turbocharged PD-TDI, approval VW506.01 is an oil that rarely requires replacement.

Engine oil approvals for Mercedes

Manufacturers also have personal approvals. car MERCEDES-BENZ. Approval MB 229.1 designates oil for MERCEDES engines operating on gasoline and diesel, put into production since 1997. Permission MB 229.31, limiting the content of phosphorus and sulfur, introduced later, is consistent with SAE 0W and SAE 5W. Multifunctional oil for engines running on both gasoline and diesel fuel with an extended service life, as well as energy saving, has the approval of MB 229.5.

Engine oil approvals for BMW (BMW)

For cars manufactured since 1998, it is proposed to use oils with the approval designation “BMW long life-98", which comply with ACEA A3 / B3 standards, with an extended service life. "BMW Long life-01" - oil approval, recommended for car engines produced at the end of 2001. With increased engine load in difficult conditions, it is recommended to use oils with a BMW Long life-01 FE approval. In modern BMW cars use motor oils with the approval "BMW Long life-04".

Engine oil approvals for Renault

In 2007, RENAULT manufacturers developed tolerances that meet the main ACEA requirements:

Renault RN0700 - ACEA A3 / B4 or ACEA A5 / B5.
Renault RN0710 complies with ACEA A3/B4 conditions.
Renault RN0720 complies with ACEA C3 conditions (some accessories from Renault).
The RN0720 approval was created for use in modern vehicles running on diesel fuel with a particulate filter.

Engine oil approvals for Ford (FORD)

Ford approved WSS-M2C913-A grade SAE 5W-30 engine oil is calculated for initial use and subsequent replacement. Such an oil meets all the requirements and standards for the following classifications: ACEA A1-98, ILSAC GF-2 and additional Ford requirements.

The oil, which has Ford M2C913-B approval, meets the required ACEA A1-98 and B1-98, ILSAC GF-2 and ILSAC GF-3 standards, is recommended for initial use and subsequent replacement in cars with diesel and gasoline engines.

In 2012, the Ford WSS-M2C913-D approval was developed and introduced. Engine oils with this rating are available for all Ford diesel vehicles. The exception is Ford models Ka TDCi put into production before 2009, and engines manufactured from 2000 to 2006. The approval provides for an extended oil life and refueling with high content sulfur or bio-diesel fuel.

Ford WSS-M2C934-A approved engine oil is designed for an extended operating period and is intended for use in vehicles with a diesel engine and particulate filter(DPF). Oil that meets Ford WSS-M2S948-B approval meets ACEA C2 classification standards (for diesel and gasoline engines with a catalyst). The presence of this tolerance indicates that the viscosity of the oil corresponds to SAE 5W-20 with reduced soot formation.

When choosing engine oil, consider the following:

Selecting the appropriate chemical composition oils - synthetic, semi-synthetic or mineral.
SAE viscosity classification standards (winter, summer or universal).
A set of additives that meets the requirements (formulated in ACEA and API classifications).
Pay attention to which car brands the product is intended for (this information can be seen on the container label).
It is important not to lose sight of additional indicators and oil tolerances (for example, the Long life designation indicates that the oil is suitable for use in vehicles with an extended replacement service life).
In the features of some compositions, it is possible to determine a combination with engines that have an intercooler, turbocharging, valve lift adjustment, timing phases and recirculation gas cooling.

Classification of motor oils API(American Petroleum Institute) is widely recognized as setting minimum performance standards and quality levels for gasoline and diesel engine oils. This classification has been significantly improved as the requirements for the quality of lubricants have increased, which, in turn, was caused by a significant improvement in engine technology, which also entailed an increase in the power of engines of these sizes, an improvement in the quality of the metal from which engine parts are made and an increase in mechanical strength, as well as, of course, an increase in operational loads.

Engine oils for gasoline engines are designated in this classification by the letter S( service station) , and the categories range from (lightest duty oils with little or no additives) to very newest category(oils for modern powerful, multi-valve engines, often with turbo and supercharged). Oils for diesel engines differ in a similar range of categories, where the name of the category begins with the letter C (commercial). This includes categories from to . These are oils designed to work in the latest diesels and under current operating conditions.

The following is short description of all categories in their evolutionary development in terms of service classifications of motor oils of the American Petroleum Institute. In cases where there is an "obsolete category" mark, this means that this category has been replaced by a new category.

Performance standards API are specified using the abbreviations API SJ and API CE:
. the first letter indicates the type of engine (S = petrol and C = diesel)
. the second letter indicates the performance level, and the lower the performance level, the higher the letter in the alphabet.

PETROL ENGINES

API SG
Oils for use in gasoline engines in 1989. For use in modern gasoline engines cars, vans and light trucks maintained in accordance with the manufacturer's recommended procedures. Oils designed for this application provide improved protection against engine deposits, oil oxidation and engine wear over previous categories, as well as protection against rust and corrosion. Oils of category SG meet the requirements for operation in diesel engines and can be used where categories , , SF / CC or SE / CC are recommended.

API SH
Oils for use in gasoline engines in 1994. The category was adopted in 1992 to define the characteristics of motor oils recommended since 1993. For normal use in gasoline engines of today's fleet of cars, vans and light trucks, serviced according to the recommendations and instructions of the manufacturers. This category exceeds the requirements of the category and was developed to replace it to improve anti-carbon, antioxidant, anti-wear qualities of oils and protect against rust and corrosion. Oils in this category that meet API SH requirements have been tested in accordance with the requirements of the Chemical Manufacturers Association (CMA). The product is approved by the Code of Practice and can be used according to API recommendations for base oil interchangeability and viscosity grade performance testing. Oils in this category may be used where the category and earlier categories are recommended.

API SJ
Oils for use in gasoline engines in 1996. Operational API category SJ characterizes engine oils sold on the market since 1996. SJ includes the same minimum values as SH, which it should replace, as well as Additional requirements to the control of carbon formation and work at low temperatures during bench tests. Oils in this category are intended for normal use in gasoline engines of modern and earlier passenger cars and sports cars, Vehicle, vans and light trucks serviced according to manufacturers' recommendations and instructions. Oils meeting the requirements of API SJ may be used where the category and earlier categories are recommended.

API SL
Oils for engines of vehicles manufactured after 2000. For multi-valve, turbocharged, lean-burn, with increased requirements for energy saving and environmental friendliness. Oils meeting the requirements of API SL, SM may be used where the category and earlier categories are recommended.

API SM
The category was approved on November 30, 2004. In addition to the SL category, the anti-oxidation and anti-wear properties are improved. Improved low temperature properties. Possibility of certification under the category of energy saving ILSAC.

API SN
The category was approved on October 1, 2010. Designed for oils used in the most modern gasoline engines of passenger cars, sports cars and small vans. Oils in this category have improved antioxidant and detergent properties, provides high protection against wear and corrosion. Enhanced high temperature properties for use in turbocharged engines. Can be used where SM and SL oils are recommended. Some oils in this category may meet the ILSAC GF-5 specification and qualify as energy efficient.

EU API
Energy Efficiency Classifications for Gasoline - EU 1995. There are two grades that define the category of gasoline engine oil designed to improve fuel economy. TESU stands for oils that improve fuel economy in standard tests by at least 1.5% compared to conventional oils, and TEC-IIY by at least 2.5%

DIESEL ENGINES

API CE
Oils for use in diesel engines 1983 (obsolete category). For use in certain powerful engines with turbocharging and additional compression, manufactured since 1983 and operating at heavy loads both low and high frequency shaft rotation. They can also be used in conditions for which category oils are recommended.

API CF
Used in diesel engines with indirect injection - CF 1994. Typical use for diesel engines with indirect injection, as well as other types of diesel engines using various types of fuel, including those with a high sulfur content (for example, more than 0.5% by weight ). CF oils are effective in preventing piston deposits, wear and corrosion of bearings containing copper, which are of great importance in these types of engines, and can be drawn in in the usual way, supplied by a turbocharger or supercharger. Oils in this technical category may be used instead of oils.

API CF-4
Oils for use in diesel engines 1990 For typical use in four-stroke diesel engines running on high speeds where the requirements exceed the capabilities of the category and application is required instead of oils of the CE category. Provides improved oil consumption and protection against piston deposits. In particular, they are effective in diesel engines of powerful tractors and vehicles on the highway. In combination with the appropriate category, they can be used in gasoline engines if recommended by the manufacturer.

API CF-2
Used in heavy duty two-stroke diesel engines - CF-2 1994. Typical use for two-stroke engines that require highly effective prevention of cylinder and ring wear and deposits. has improved performance and can be used instead of other materials if necessary.

API CG-4
The category was introduced in 1995. Oils designed for heavy-duty, high-speed, four-stroke diesel engines trucks mainline type using fuel with a sulfur content of less than 0.05% by weight and non-mainline type (sulfur content can reach 0.5% by weight). Effectively suppress the formation of high-temperature soot on pistons, wear, foaming, oxidation, soot formation (these properties are necessary for engines of new mainline tractors and buses). The category was created to meet the requirements of the US Emissions Standards (Revision 1994). Replaces oils of categories , and . The main disadvantage that limits the use of oils of this category in the world is the relatively large dependence of the oil resource on the quality of the fuel used.

API CH-4
The category was introduced on December 1, 1998. Oils in this category are designed for high-speed, four-stroke engines that meet the stringent 1998 emission standards. Meet the highest requirements not only American, but also European manufacturers diesel engines. Specially formulated for use in engines using fuels with sulfur content up to 0.5% by weight. Unlike the category, the use of diesel fuel with a sulfur content of more than 0.5% is allowed, which is important advantage in countries where high-sulfur fuels are common (South America, Asia, Africa). Oils meet the increased requirements for reducing valve wear and reducing carbon deposits. Replace oils of categories , , and .

API CI-4
Category introduced since 2002 . Oil corresponding to this level has higher dispersing properties (amount of detergent-dispersant additives), has increased stability to thermal oxidation in comparison with the class , provides a reduction in oil consumption for waste due to a decrease in volatility and a decrease in evaporation losses under the influence of gases at operating temperature 370°C. Improved cold pumpability, extended life of engine seals due to improved oil compatibility with seals. The class was introduced taking into account the tightening of requirements for the environmental performance of engines produced from October 1, 2002.

API CI-4PLUS
Service category for diesel engines with more stringent soot requirements. Upon receipt of this classification, engine oil is tested in 17 engine tests.

API GL-3
Oils for gears operating under moderate conditions. Contain up to 2.7% antiwear additives. Designed for lubrication of conical and other gears of trucks. Not intended for hypoid gears.

API GL-4
Oils for gears operating in conditions of varying severity - from light to heavy. Contains 4.0% effective extreme pressure additives. Designed for bevel and hypoid gears with small axle displacement, for gearboxes of trucks, for drive axle units. API GL-4 oils are designed for non-synchronized transmissions in North American trucks, tractors and buses ( commercial vehicles), for main and other gears of all vehicles. Currently, these oils are also the main oils for synchronized gears, especially in Europe. In this case, the label or data sheet of the oil must contain inscriptions about this purpose and confirmation of compliance with the requirements of the machine manufacturers.

API GL-5
Oils for the busiest gears operating in harsh conditions. Contains up to 6.5% effective extreme pressure and other multifunctional additives. The main purpose is for hypoid gears with a significant axle offset. Used as universal oils for all other units mechanical transmission(except gearbox). For a synchronized manual transmission, only oils that have a special confirmation of compliance with the requirements of machine manufacturers are used. Can be used for limited slip differential if they meet the requirements of the specifications MIL-L-2105D(in the US) or ZF TE-ML-05(in Europe). Then the class designation has additional characters, for example, API GL-5+ or API GL-5 SL. Oils for the busiest gears operating in very difficult conditions (high speeds sliding and significant impact loads). Contains up to 10% high performance extreme pressure additives. Designed for hypoid gears with significant axle offset. Correspond to the highest level of operational properties.

API MT-1
Oils for highly loaded units. Designed for non-synchronized manual transmissions of powerful commercial vehicles (tractors and buses). Equivalent to oils, but with increased thermal stability.

API PG-2
Oils for transmissions of driving axles of powerful commercial vehicles (tractors and buses) and mobile equipment. Equivalent to oils, but with improved thermal stability and improved elastomer compatibility.

For mechanical gearboxes (except hypoid ones), oils and are mainly used; for hypoid main gear: API GL-4 - for medium loaded gears and API GL-5 - for heavily loaded gears, including hypoid gears with significant axle offset. Oil companies produce universal oils designed both for gearboxes with synchronizers and for heavily loaded hypoid gears.

Lubricants for various machines people have been using whiter for more than 150 years. Since they produced two types of raw materials (vegetable origin, and oil), there was no special classification.

A thick consistency (such as tar) was used for lubrication wheel hubs, more liquid options were poured into crankcases with moving mechanisms.

The further development of engine building made ever higher demands on consumables. There were standards for compatibility with types of internal combustion engines, applicability to different conditions and even quality. For example, the classification of motor oils according to API.

Today, any lubricant contains up to 10 different certificates, approvals and classifiers. Our material will help you understand the numbers and abbreviations.

What is an API?

API - American Petroleum Institute (American Fuel Institute), develops specifications, standards and classifiers for engine oils for internal combustion engines. The oil industry has developed rapidly, technological opportunities have appeared to produce lubricants with various properties. Automakers, continuously improving their units, began to impose increased requirements on engine and transmission oils.

In order not to tie oil brands to automotive brands, the largest players in the consumables market decided to develop a unified system of standards.

The task was not just to bring the relationship of car factories and oil refineries to a common denominator (acting within the framework of free competition). The buyer of lubricants also had to have the right to freely choose the manufacturer.

motor classification API oils and ILSAC - video workshop

The first universally recognized standards were the norms of the technical unions SAE and ASTM. But these designations spoke only about the basic (rather technological) properties of the lubricant.

There was a need not only to bind technical fluids to certain types of motors, but also to develop a quality system. The buyer must understand in which case he pays more, and what benefits he gets.

The so-called “quality classifier” was developed by the US Petroleum Institute (API for short). The first mention of the API system for engine oil appeared in the late 60s, when, together with technical unions SAE and ASTM have developed a single standard that operates within ASTM D 4485 and SAE J183 APR96.

Then, over the course of 15 years, the system was adapted to the GOSTs of various countries, research was carried out with the participation of leading engineers from the unions of automobile manufacturers (AAMA) and engines (EMA). As a result, two methods were gradually introduced, in which the specification of oils according to API was "legalized":

EOLCS engine oil licensing and certification system;
SMA Code of Practice.

The specification of oils according to API is recognized not only in North America. Since the mid-80s, most countries have been using these standards, not to mention auto concerns.

This is convenient for the buyer: entering the store, you can easily navigate. Just look at the technical specifications (SAE) and API quality standard. Information is on the label of any lubricant.

Some countries have a national system of standards: for example, the Russian GOST. According to international conventions, all systems of quality standards are compatible with each other and have an equal semantic load.

For example:

SC / CA (American API standard) = B (Russian GOST);
CD (American API standard) = D2 (Russian GOST).

The main indicators that the manufacturer puts into the alphanumeric designation of the API standard:

The first letter in the classification indicates the type of fuel. S - gasoline, C - diesel. Consumables for diesel fuel are also suitable for commercial vehicles (tractors, combines, excavators, etc.), including diesel engines.

The additional abbreviation EC refers to the energy-saving properties of the oil. Such a lubricant has a high fluidity, which significantly reduces the resistance between rubbing parts.

The second letter (today from A to N) defines that very quality. The farther the letter is from the beginning of the alphabet, the higher it is. It is by this symbol, in contrast to the manufacturer's advertising messages, that the buyer determines what the high (or low) cost of the consumable is set for.

Let's consider each of the classifications in more detail:

API engine oil classification for gasoline engines

Modern gasoline classification engine oil according to API is indicated by symbol combinations from SA to SN. Car factories set tolerances in the following order: each next class of oil is compatible with the previous one, backward compatibility is undesirable.

This means that an API SG engine can be filled with SN oil. But SF oil cannot be filled in instead of SL.
The decryption API looks like this:

API class	Applicability Status	Aggregate Compatibility
SM	current	Introduced into circulation since 2004, and suitable for everyone modern motors gasoline-powered, including high-revving turbine units.
SL	current	Applied since 2001, has the function of energy saving, designed for an extended replacement interval. This class replaces the letter K, to eliminate confusion with internal classification Korean oils.
SJ	current	Introduced since 1996, it has 2 subclasses. Since 2001, oils have been certified in the API SJ / EC energy saving category.
SH	outdated	The classification is classified as conditionally valid. After its introduction in 1992, it was subjected to additional certification for the energy saving class. With the designations API SH / EC and API SH / ECII, it can be used in modern engines without turbocharging.
SG	outdated	The class was introduced in 1988 and is compatible with engines manufactured before 1993. It has good anti-wear properties. For older engines, it is better suited than engine oil of more recent categories.
SF	outdated	Available for units older than 1988. Good compatibility with leaded gasoline. For motors operating on a two-stroke cycle - the best ratio of lubricating properties.
SE	outdated	High-class oil for work in the conditions of the big loading (the forced motors). Compatible with units manufactured between 1972 and 1980.
SD	outdated	Suitable for motors with a high load, the degree of forcing is medium. Years of production of units - 1967-1971.
SC	outdated	Suitable for motors with a high load, but without forcing. Years of production of units - 1964-1967.
SB	outdated	It is intended for motors operating with an average load, can only be used according to the direct instructions of the manufacturer of the units.
SA	outdated	It is intended for gasoline engines operating under low load and may only be used on the direct instructions of the manufacturer of the units.

Video lecture - Classification of motor oils according to SAE and API

API Oil Quality Classes for Diesel Engines

The classification of diesel engine oils allows you to accurately identify Consumables by type of fuel. The API designation begins with the Latin letter C.
Table automotive oils for heavy fuel is as follows:

API class	Applicability Status	Aggregate Compatibility
CJ-4	current	The standard was developed for motors from 2007 of release. The main emphasis in certification is made on the compliance of ash content and sulfur content.
CI-4PLUS	current	In addition to the main characteristics of the content of harmful elements, these oils do not oxidize under high load, and also do not evaporate "to waste".
CI-4	current	The standard was certified in 2002 to meet stringent environmental regulations. High fluidity allows to work in conditions of low ambient temperatures.
CH-4	current	This API oil class is designed for engines manufactured prior to 1998. Basically, it corresponds modern standards, but strongly depends on the quality of diesel fuel. It contains additives that prevent valve wear.
CG-4	outdated	Mainly used for heavy commercial vehicles. The certificate implies universality in terms of fuel quality, but in practice it is better to fill the engine with high-quality diesel fuel.
CF-4	outdated	Universal oil for diesel and gasoline engines operating on a four-stroke cycle. Compatible with units manufactured before 1990.
CF-2	outdated	Applicability - two-stroke motors operating under high loads.
CE	outdated	The standard is compatible with diesel engines manufactured before 1983. Works well on high pressure turbo engines.
CD	outdated	Introduced at the turn of the 50-60s for operation on agricultural machinery. It is still used on older units.
CC	outdated	Introduced in 1961, almost never used.
CB	outdated	A slightly improved formula of the previous API CA standard
CA	outdated	Designed for lightly loaded simple aspirated.

What is the difference between gasoline and diesel engine oils?

The specification of engine oils according to API does not allow the use of consumables in different engines. Modern units are very different (under working conditions) depending on the fuel.

Temperature conditions, shock loads, the presence of soot or ethylene - all this is taken into account in the classifier formula. Some manufacturers average applicability standards, and produce consumables that can be used in both diesel and gasoline engines. This marking contains the symbols C and S.

However, the buyer should be aware that universal oils are inferior in quality to specialized lubricants.

Lubricants began to be used long before our era. And if earlier vegetable fats and fats of animal origin were used as them, then starting from the 60s of the last century they were replaced by refined products. After that, the active development and improvement of motor oils began, and about 70 years ago, the first polymeric viscosity modifiers appeared, thanks to which different classes and varieties soon appeared in motor oils, corresponding to the temperature regime of a certain season, and all-weather types of lubricants appeared.

Since that moment, the composition and technical qualities of oils have undergone many changes, but their main purpose has remained unchanged. Engine oil is designed to cover moving parts with a thin, but at the same time strong, film, thereby protecting them from friction between themselves.

To date, there are several oil classification systems that allow you to classify lubricants according to their performance, technical characteristics, and purpose. Among the main generally accepted systems, one of the most famous is the API classification of engine oils. It was introduced at the end of the 50s of our century by the American Petroleum Institute, and the fundamental principle in it is the classification into two categories - S and C, that is, for gasoline and diesel engines, respectively.

S and C oil specifications

As noted above, API system involves a division into two main categories, however, there is a third designation for the quality of lubricants. Of these, each type is independent:

All these standards are indicated by a two-letter index, for example, SN, SM, SH, SG, CF, CI, where the second value is an indicator of the level performance characteristics. At the same time, the closer to the end of the Latin alphabet is the letter in the designation, the higher the oil level according to API. For example, a product designation such as API SL, SM, or SN indicates superiority over API SF.

Gasoline engines: quality classes, their designations and decoding

Group	Description
SN	SN lubricants differ from previous SM specifications in that they contain much less phosphorus, which gives them additional energy saving qualities and makes SN compatible with the latest systems aimed at neutralizing exhaust gases. The SN class was approved in the fall of 2010 and is used in the engines of the most modern cars. It should be noted that oils with the API SN specification are close in their characteristics to ACEA C2, C3, C4, so SN can successfully replace SM class grease.
SM	SM was first introduced at the end of 2004. This class is more common today than CN, because it is intended for modern gasoline engines, including multi-valve and turbocharged engines. The lubricant of this category was developed taking into account the improvement of engines, therefore it is designed to increase their environmental safety and be more durable. SM differs from the previous category SL in greater oxidation resistance and excellent protective properties against the formation of sludge and deposits, which certainly affects the high quality of lubricants. Two years after the release of SM, a category of oils for diesel engines was developed with the designation CJ4. SM specification products are designed for cars from 2004 and are designed specifically for them.
SL	The SL class was developed shortly before the release of SM and SN. It has been developed for car engines manufactured since 2001 and absolutely meets all modern standards and requirements, including high environmental friendliness and energy saving. SL are designed for modern engines, including multi-valve, turbocharged and engines adapted to run on lean fuel mixtures. On lubricants SL groups may well work with engines for which products of the SJ category are intended. Thanks to properties such as low volatility, SLs are distinguished by their long-term retention of their qualities, due to which the engine oil change interval is noticeably extended. To date, this category is valid and is widely used by modern car owners.
SJ	This class is also active today. It was approved in November 1995, although the product was certified only a year later. Therefore, SJ category oils are used for cars with a gasoline engine, starting in 1996. They are successfully used in the engines of passenger cars and sports cars, as well as in the engines of minibuses and small trucks. SJ shows good technical characteristics, including resistance to the formation of deposits and deposits, as well as the ability to maintain its properties at low temperatures. According to these properties, SJ category oils are very close to SH class products, therefore they are quite suitable for use when the automaker recommends the use of SH category oils for a car.
SH	This category was created in 1992 and is considered conditionally valid. Oils included in this group are used in car engines manufactured in 1996 and earlier. In terms of its qualities, this class surpasses SG category oils, because it was developed to replace it. Therefore, SH class oils are successfully used for vehicles in which SG is recommended.
SG	Class SG is for motors manufactured in 1193 and earlier. Oils in this category are distinguished by excellent protection against carbon deposits and are resistant to oxidation and corrosion processes. SG oils meet all requirements for motor oils intended for diesel engines. API engines CC, which means SG, can be used for machines in which the manufacturer recommends the use of categories SF and SF / CC, as well as SE and SE / CC.

Specification of oils for diesel engines

Among modern engine oil specifications, CI and CF oils are the most popular. They are designed taking into account all the features of modern diesel engines and meet all standards.

Category CI -4 approved in 2002. They are designed for various diesel engines, CI specification products have high oxidation stability and contain dispersant additives. CIs are quite environmentally friendly compared to previous classes of oils. It is worth noting that from general category CI allocate another class - CI -4 PLUS. The improved CI -4Plus class was developed taking into account the stringent requirements for oil volatility, its oxidation during elevated temperatures and soot formation.

The CF specification was created for diesel engines with indirect injection. They are distinguished by a high content of various additives that prevent deposits on pistons, as well as protect against wear and corrosion of internal parts with copper content, such as bearings.
The CF class can be designated CF-4 and CF-2, which means motor oils intended for use in four-stroke and two-stroke (respectively) diesel engines.
At the same time, CF-4s are designed for engines operating in accelerated mode, and CF-2s are ideal for engines that are constantly subjected to increased loads.

API Classifications Video

The American Petroleum Institute engine oil classification system was created in 1969. Usually, the API classification is associated with the quality of engine oil.

The API classification divides motor oils into two types - oil for gasoline engines and oil for diesel engines. For each of these types, quality classes are provided that describe a set of properties and characteristics of the oil. that this oil either does not have an API certificate at all, or the quality class assigned to it is very outdated.

The first letter of the coding indicates the type of oil:

S– oil for gasoline engines
C- oil for diesel engines.

There are oils that can be used in both types of engines. This oil is assigned two classes - for diesel and for gasoline engines. On the oil label, these classes are separated by a slash - for example API approval SL/CF. In this case, the class of oil that corresponds to the more preferred (according to the manufacturer of the motor oil) application is put first. That is, in the above case, the main purpose of the oil is for gasoline engines, but the manufacturer also allows its use in diesel engines.

API Classes for Gasoline Engines

API SM- the class was approved on November 30, 2004. Engine oils for modern gasoline (multi-valve, turbocharged) engines. Compared to the SL class, engine oils that meet the requirements of API SM must have more high rates oxidation protection and premature wear engine parts. In addition, standards regarding the properties of the oil at low temperatures have been raised. Engine oils in this class can be certified to the ILSAC energy saving class. Engine oils that meet the requirements of API SL, SM can be used in cases where the SJ or earlier class is recommended by the vehicle manufacturer.

API SL - engine oils for engines of cars manufactured after 2000. In accordance with the requirements of car manufacturers, motor oils of this class are used in multi-valve, turbocharged engines running on lean fuel mixtures that meet modern increased environmental requirements, as well as energy saving. Oils that meet the requirements of API SL can be used in cases where the SJ or earlier class is recommended by the automaker.

API SJ - engine oils for use in gasoline engines since 1996. The API class SJ describes motor oils that have been 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 trucks, which are serviced in accordance with the requirements of vehicle manufacturers. SJ has the same minimum standards as SH and additional requirements for carbon build-up and low temperature operation. Engine oils meeting the requirements of API SJ may be used where SH or earlier is recommended by the vehicle manufacturer.

API SH- engine oils for gasoline engines since 1994 of release. The class was adopted in 1992 for motor oils recommended since 1993. This class is characterized by higher requirements than the SG class, and was developed as a substitute for the latter, to improve 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 of cars, minibuses and light trucks, in accordance with the recommendations of their manufacturers. Engine oils this class tested in accordance with the requirements of the Chemical Manufacturers Association (CMA). Engine oils of this grade may be used when grade SG or earlier is recommended by the vehicle manufacturer.

API SG- engine oils for gasoline engines since 1989 of release. 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, 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 grade engine oils meet API CC diesel engine oil requirements and can be used where SF, SE, SF/CC or SE/CC grades are recommended.

API SF- engine oils for gasoline engines since 1980 (obsolete class). These engine oils were used in gasoline engines manufactured in 1980-1989, subject to the recommendations and instructions of the engine manufacturer. Provide enhanced oxidation resistance, improved protection against wear of parts, in comparison basic characteristics SE motor oils, as well as more reliable protection against soot, rust and corrosion. SF class engine oils could be used as substitutes for the previous SE, SD or SC classes.

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

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

API SC- engine oils for gasoline engines, starting from 1964 (obsolete class). They were usually used in the engines of cars and some trucks manufactured in 1964-1967. Reduce high and low temperature deposits, wear and protect against corrosion.

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

API SA- engine 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 may only be used if they are recommended by the engine manufacturer.

API Classes for Diesel Engines

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

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

API CH-4- the class was introduced on December 1, 1998. Engine oils of this class are used in four-stroke diesel engines that operate in high speed conditions and meet the requirements of the 1998 emission standards and standards. API CH-4 motor oils meet the fairly stringent requirements of both American and European diesel engine manufacturers. Class requirements are specifically designed for use in engines running on high-quality fuels with a specific sulfur content of up to 0.5%. At the same time, unlike the API CG-4 class, the resource of these motor oils is less sensitive to the use of diesel fuel with a sulfur content of more than 0.5%, which is especially important for the countries of South America, Asia, and 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 internal surfaces. They can be used as substitutes for API CD, API CE, API CF-4 and API CG-4 motor oils in accordance with the recommendations of the engine manufacturer.

API CG-4- the class was introduced in 1995. Engine oils of this class are recommended for four-stroke diesel engines of buses, trucks and tractors of the main and non-main line type, which are operated in high load and high speed modes. API CG-4 engine oil is suitable for engines that use high quality fuels with a specific sulfur content of not 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% ). API CG-4 certified motor oils should more effectively prevent wear of internal engine parts, the formation of deposits on internal surfaces and pistons, oxidation, foaming, and soot formation (these properties are especially needed for engines of modern long-distance buses and tractors). The API CG-4 class was created in connection with the approval in the USA of new requirements and standards for the ecology and toxicity of exhaust gases (revised in 1994). Engine oils of this class can be used in engines for which API CD, API CE and API CF-4 classes are recommended. The main disadvantage that limits the mass use of motor oils of this class, for example, in Eastern Europe and Asia, this is a significant dependence of the motor oil resource on the quality of the fuel used.

API CF-2 (CF-II)- motor oils designed for use in two-stroke diesel engines that operate in harsh conditions. The class was introduced in 1994. Motor oils of this class are usually used in two-stroke diesel engines that operate under increased stress. API CF-2 oils must contain additives that provide protection increased efficiency from wear on internal engine parts such as cylinders and rings. In addition, these motor oils must prevent the accumulation of deposits on the internal surfaces of the motor (improved cleaning function). Engine oil certified to API CF-2 has improved properties and can be used in place of older similar oils, subject to the manufacturer's recommendation.

API CF-4- engine oils for use in four-stroke diesel engines since 1990 of release. Engine 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 oil quality exceed the capabilities of the CE class, so CF-4 engine oils can be used instead of CE class oils (if there are appropriate recommendations from the engine manufacturer). API CF-4 motor oils must contain appropriate additives that provide a reduction in motor oil fumes, as well as protection against carbon deposits in 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 trips by motorways. In addition, these engine oils are sometimes assigned the dual API CF-4/S grade. In this case, subject to the availability of relevant recommendations from the engine manufacturer, these motor oils can also be used in gasoline engines.

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

API CE- engine oils for use in diesel engines since 1983 (obsolete class). Car 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 operate under heavy duty conditions. Subject to the availability of relevant recommendations from the engine manufacturer, these motor oils could also be used in engines for which CD class engine oils were recommended.

API CD II- engine oils for use in heavy-duty diesel engines with two-stroke working 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 using such motor oils was the use in heavy powerful diesel engines, which were installed mainly on agricultural machinery. Engine oils of this class meet all the performance standards of the previous CD class, in addition, the requirements for highly effective engine protection against carbon deposits and wear have been significantly increased.

API CD- engine oils for diesel engines increased power, which were used in agricultural machinery (obsolete class). The class was introduced in 1955 for general use in some diesel engines, both naturally aspirated and turbocharged, with increased cylinder compression, where effective protection against carbon deposits 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 fuel quality (including fuel with a high sulfur content). API CD motor oils were supposed, in comparison with previous classes, to provide increased protection against bearing corrosion and high-temperature soot in diesel engines. Often referred to as "Caterpillar Series 3" motor oils, due to the fact that they met the requirements of the Superior Lubricants (Series 3) certification developed by tractor company Caterpillar.

API CC- engine oils for diesel engines that are operated in medium load conditions (obsolete class). The class was introduced in 1961 for use in some engines, both atmospheric and turbocharged, which were characterized by increased compression. Engine oils of this class were recommended for engines that were operated in moderate and high load modes. In addition, subject to the recommendations of the engine manufacturer, such motor 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 deposits and bearing corrosion in diesel engines, as well as rust, corrosion and low temperature deposits in gasoline engines.

API CB- engine oils for diesel engines operating with medium load (obsolete class). The class was approved in 1949 as an evolutionary development of the CA class using fuel 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 grade was often referred to as "Annex 1 Motor Oils" to indicate compliance with military regulation MIL-L-2104A Annex 1.

API CA- engine oils for lightly loaded diesel engines (obsolete class). Car oils of this class are designed for use in diesel engines operating in light and moderate conditions on 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 conditions. The class was widely used in the 40s and 50s of the last century and cannot be used in modern conditions unless required by the engine manufacturer. API CA engine oils must have properties that provide protection against carbon deposits on piston rings, as well as against bearing corrosion in supercharged engines, for which there are no special requirements for the quality of the fuel used.