Oils that meet the requirements of class CI-4 are intended for use in severe conditions of 4-stroke diesel engines of trucks equipped with an exhaust gas recirculation system. Such systems are installed on new models of automobile diesel engines in order to reduce the toxicity of exhaust gases.
Returning part of the exhaust gases to the outlet effectively suppresses the formation of nitrogen oxides during the combustion process, but sharply increases the requirements for the neutralizing, anti-wear and anti-corrosion properties of the oil used. Previously, the oil film on the cylinder wall interacted with combustion products only during the expansion and exhaust strokes, when the gas temperature was high. Now, during exhaust gas recirculation, combustion products come into contact with the oil film during the intake and compression strokes, when the gas temperature is much lower and conditions arise for the formation of acids.
CI-4 class oils should be used in combination with fuels containing no more than 0.05% sulfur. But even under such conditions, exhaust gas recirculation is a factor in seriously tightening the requirements for the neutralizing ability of the oil. Research has shown that not only its high base number becomes important, but also the rate of neutralization of acids by oil additives.
At the optimal temperature of the coolant and oil in the crankcase, turning on exhaust gas recirculation accelerates the reduction in alkalinity by 1.5 times.
If the engine is not warm enough, the decrease in alkalinity increases sharply. Warming up the engine quickly and maintaining optimal thermal conditions is extremely important to maintain the performance of the oil.
In terms of performance properties, CI-4 class oils are significantly superior to their old predecessors (CH-4, CG-4 and CF-4) and can replace them in engines of models of the late 90s. With such a replacement, the mileage before an oil change can be significantly increased.
To certify oils for compliance with the CI-4 class, a wide range of laboratory and engine tests are used, which includes several new methods, including long-term engine tests in engines with exhaust gas recirculation.
Of particular note is the first introduced pumpability control at -20 °C of the oil, which was operated in the engine during bench tests for 75 hours, as well as a strict assessment of the anti-corrosion properties of the oil with respect to lead, copper and tin.
The only indicator in which new American diesel oils are inferior to European ones is volatility. The norm for class CI-4 SAEW-40 is no more than 18%, and according to the European ACEA classification of oils for diesel trucks (class E) - no more than 13% in 1 hour at a temperature of 250 °C. These differences, however, are not accompanied by a reduction in oil consumption requirements during engine tests.
Engine oils are called motor oils. The requirements for quality and are determined by the specifics of operation and design of the internal combustion engine. Oils work under very difficult conditions - high temperature and pressure.
The temperature in the combustion chamber reaches 3000°C; the temperature of gases breaking into the engine crankcase during the compression stroke in diesel engines can reach 500-700°C. Thus, for normal lubrication of engine rubbing parts, the operating temperature range of engine oils must be very wide. In addition, the oil must be fluid in order to seal gaps in mating parts, and have viscosity-temperature, protective, detergent, antioxidant, lubricating and anti-corrosion properties.
Motor oils can be divided according to the following criteria:
- manufacturing technologies: mineral, semi-synthetic and synthetic;
- viscosities: winter, summer, all-season, low-viscosity and thick;
- purpose: gasoline, diesel, universal, high- and low-quality.
There is no uniform classification of oils.
Automakers from different countries are guided by their own classification.
API classification
The American classification of motor oils was developed by API (American Petroleum Institute) together with ASTM (American Society for Testing and Materials) and SAE (Society of Automobile Engineers). It sets the limits of various parameters (such as piston cleanliness, piston ring coking, etc.) using various test engines.
AR classificationIdivides motor oils into two categories:
S- for gasoline engines - SE, SF, SG,SH, SJ and SL;
WITH- for diesel engines - CC, CD, CE, CF, CG, CH and CI.
The marking consists of two letters, the first indicates the category of oil, the second - the level of performance properties.
SE- class of oils for gasoline engines 1972-1980.
SF- the cleaning and anti-wear properties of oils of this class are higher than those of SE class oils. This class meets the requirements for 1981-1988 engines. release.
S.G.- oils of this class are characterized by increased detergent and anti-wear properties, extending the service life of the engine. Meets the requirements of most engine manufacturers since 1989.
SH- the class was introduced in 1993, sets the same indicators as 80, but the test methodology is more demanding.
S.J.- the class appeared in 1996, developed in accordance with more stringent requirements for harmful emissions into the atmosphere.
SL- the class of oils was introduced in 2001. It addresses three key concerns: improved fuel efficiency, increased protection of emissions-reducing components, and increased oil life. The requirements for testing have been tightened compared to the SJ level.
Motor oils for diesel engines
SS- class of oils for diesel engines with and without turbocharging, operating under moderate loads.
WITHD- a class of oils for high-speed diesel engines with turbocharging and high specific power, operating at high speeds and at high pressures and requiring increased anti-wear properties and prevention of soot formation.
SE- a class of oils for forced diesel engines with strong turbocharging, operating under extremely high loads.
WITHF- class of oils for diesel engines with a pre-chamber used in passenger cars.
WITHF-4 - improved class of oils, replacing CE class.
WITHF-2 - this class of oils basically coincides with the previous class CF-4, but oils of this class are intended for two-stroke diesel engines.
WITHG-4 - a class of oils intended for American high-power diesel engines.
CH-4- a class of oils for diesel engines of heavy vehicles, meeting the standard for harmful emissions established in 1998. The class assumes that the engine runs on low sulfur fuel.
WITHI-4 - a new class of oils for diesel engines operated under severe conditions in high-speed four-stroke diesel engines that meet the 2004 emission toxicity standards. In terms of performance characteristics, it surpasses APICH-4, CG-4 and CF-4 oils.
ACEA classification
European classification operational properties ACEA places higher demands on oils compared to the API classification. ACEA is close to the vehicle fleet and operating conditions characteristic of the European zone.
The classification divides oils into three categories:
A- gasoline engines (A1, A2, AZ and A5);
IN- low-power diesel engines installed on low-power cars and trucks (B1, B2, VZ, B4 and B5);
E- diesel engines for heavy transport (E1, E2, EZ, E4, E5 and
The number after the letter indicates the level of requirements. The higher the number, the higher the requirements. The exceptions are levels A1 and B1, which refer to low-viscosity oils, the so-called “fuel-saving”. Class B4 basically coincides with class B2, but is supplemented by tests on engines with direct fuel injection.
SSMS classification
The CCMS classification was introduced by European car manufacturers.
In 1996, it was officially replaced by the ACEA classification. However, the CCMS classification still exists in the operating manuals of older cars and in recommendations for the use of oils.
The CCMS classification divides oils into three categories:
- for gasoline engines (category G);
- for diesel engines of small cars (category PD);
- for heavily loaded diesel engines (category D).
ILSAC classification system
American Automobile Manufacturers Association AAMA and Japan Automobile Manufacturers Association JAMA jointly created the International Committee for Standardization and Approval of Motor Oils ILSAC (International Lubricant Standardization and Approval Committee).
On behalf of this committee, quality standards for oils for gasoline engines of passenger cars are issued: ILSAC GF-1, ILSAC GF-2, ILSAC GF -3.
The new classes GF-3 and API SL differ from the previous ones (GF-2 and API SJ) by significantly better antioxidant and anti-wear properties, as well as lower volatility. The requirements for both classes are largely the same, but the GF-3 is necessarily energy efficient.
Global DHD classification
Since February 2001, the Global World Specification Global DHD-1 came into force, which combined the ACEA E5, JASO DX-1 and API CH-4 specifications. It defines the basic requirements for motor oils for heavy duty vehicles (over 3.9 tonnes) with diesel engines manufactured since 1998 and meeting new exhaust emission requirements.
Thus, this specification takes into account all the requirements of European, American and Japanese manufacturers of heavy diesel engines.
This specification requires oils with a high base number (TBN) and a high-tech additive package.
The Global DHD -2 specification is expected to come into effect in 2005, when SCR (Selective Catalytic Red) catalysts will be installed on heavy-duty vehicles. Oils meeting this specification must meet the EVRO IV and EVRO V emissions standards (2008).
Global DLD classification
The new global specifications Global DLD were jointly developed by the European Automobile Manufacturers Association (ACEA), the United States Engine Manufacturers Association (EMA) and the Japan Automobile Manufacturers Association ( JAMA). They came into effect on January 1, 2001 and are specifications for motor oils for high-speed four-stroke diesel engines in passenger cars and light commercial trucks (up to 3.9 tons). Global DLD specifications meet the requirements of both new engine designs with stringent exhaust emissions standards and older vehicles manufactured anywhere in the world. The Global DLD specifications include three categories - DLD-1, DLD-2 and DLD-3.
The performance characteristics of DLD-1 motor oils must meet essential requirements, including anti-corrosion properties, which make such oils suitable for markets with high sulfur content of fuel (World Wide Fuel Charter Category).
Motor oils are specified to provide the upper level of performance requirements plus fuel economy requirements.
Oils of the DLD-3 specification must provide the highest level of performance characteristics.
Classification of oils for two-stroke engines
The level of requirements for oils for two-stroke engines is determined by the API classification, which is based on laboratory tests and engine tests. Oils for two-stroke engines are divided into four API classes.
Note. The API-TA and API-TV levels are not the same and are not interchangeable.
JASO classification
Classification of Japanese manufacturers for two-stroke engines. Particular attention in the list of requirements is paid to reducing smoke generation. According to the level of requirements, oils are divided into three categories: FA, FB and FC.
Requirements increase from left to right - from A to C.
As a rule, during the warranty period, oil changes are performed at a service station using oil brands approved by the vehicle manufacturer. If the warranty period has already expired, then the problem of competent choosing the right brand of oil. And there is plenty to choose from - store shelves are filled with a variety of products from different manufacturers.
Remember, you cannot fill the engine with oil if its viscosity does not meet the requirements of the engine operating instructions!
- oils can be mineral, synthetic and semi-synthetic, designed for use in gasoline or diesel engines;
- preference should be given to those oils that are recommended for this vehicle by the manufacturer;
- you should choose according to viscosity class according to SAE, quality class according to ACEA (CCMC) or API;
- It is not recommended to mix foreign oils with domestic ones, since the performance properties and stability of such mixtures are, as a rule, unknown;
- before using another oil, the lubrication system must be flushed;
- foreign oils can be used in domestic equipment only if there is a certificate or other document confirming the compliance of a given batch of oil with the requirements of company specifications for all indicators;
- If you want to fill the engine with synthetic oil instead of mineral oil, do not rush to do this without consulting a specialist, since synthetic oils may contain substances that are poorly compatible with the materials used in the manufacture of car parts (this especially applies to domestically produced cars).
How to switch from one brand of motor oil to another?
If the engine previously used high-quality oil from leading companies, the replacement intervals were not violated, and there are no significant deposits in the engine, then switching to using another brand of oil is carried out in accordance with the usual recommendations for changing the oil.
In cases where the brand of oil poured into the engine is unknown, if the mileage of the car after the last replacement is not determined and there are significant deposits on the internal surfaces of the engine, it is necessary to perform flushing engine.
Replacing mineral oil with synthetic oil is not always justified and is not recommended in the following cases:
- if there are significant deposits on the internal surfaces of the engine. After replacement, the synthetic oil will begin to intensively wash away deposits and they can clog the oil receiver. The lubrication system will fail and, as a result, the engine will fail;
- if seals (oil seals, oil scraper caps, etc.) have lost elasticity and have microcracks. They will not be able to seal the connecting parts, and oil leaks will appear;
- Using synthetic oils on old, worn-out engines is a waste of money.
The API engine oil classification system (API Engine Service Classification System) has been developed since 1969 as a result of joint work API, ASTM And SAE. The system is fully outlined in ASTM D 4485 standards "Standard specification for the quality of performance properties of motor oils"(Standard Performance Specification for Performance of Engine Oils) and SAE J183 APR96 "Engine Oil Performance and Engine Service Classifications (Other than "Energy Conserving"). New quality a step in the development of quality and classification of motor oils was made in 1983-1992, when, under the leadership API and the participation of representatives of car manufacturers ( AAMA), engines ( EMA) and technical unions ( ASTM And SAE) was created and developed "EOLCS motor oil licensing and certification system"(Engine Oil Licensing and Certification System, API Publication No. 1509). This system is constantly being improved. Currently, motor oils are certified in accordance with the requirements of EOLCS and "Code of rules of the SMA"(CMA Code of Practice).
According to the API system (ASTM D 4485, SAE J183 APR96), three operational categories (three rows) of purpose and quality of motor oils are established:
S (Service)- consists of quality categories of motor oils for gasoline engines, in chronological order. For each new generation, an additional letter is assigned in the alphabet:
API SA, API SB, API SC, API SD, API SE, API SF, API SG, API SH and API SJ (category SI - intentionally omitted by API to avoid confusion with the International System of Measures).
Categories API SA, API SB, API SC, API SD, API SE, API SF, API SG are currently considered invalid as outdated, however, in some countries oils of these categories are still produced; the API SH category is “conditionally valid” and may used only as an additional one, for example API CG-4/SH.
The SL class was introduced in 2001 and differs from SJ by significantly better antioxidant, anti-wear, anti-foaming properties, as well as lower volatility;
C (Commercial)- consists of categories of quality and purpose of oils for diesel engines, in chronological order. For each new generation, an additional letter is assigned in the alphabet:
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-4.
Categories API CA, API CB, API CC, API CD, API CD-II are currently recognized as invalid as obsolete, but in some countries oils of these categories are still produced;
EC (Energy Conserving)- energy-saving oils - a new range of high-quality oils, consisting of low-viscosity, easy-flowing oils that reduce fuel consumption according to the results of tests on gasoline engines.
Engine oils that have low viscosity at both low and high temperatures can be certified to meet the API EC "Energy Conserving" Oil category. Previously, energy savings were determined using the Sequence VI method (ASTM RR D02 1204). This methodology was used to certify oils of the API SH category for levels (degrees) of energy saving: API SH/EC - 1.5% fuel economy and API SH/ECII - 2.7% fuel economy, compared to the SAE 20w-30 reference oil. Roman numerals after the letters EC indicate the level of fuel economy achieved (EC II - 2.5%).
Impact of emission control systems
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 a different type of engine. For example, API CG-4/SH is an oil optimized for use in diesel engines, but it can also be used in gasoline engines that require an API SH or lower oil category (SG, SF, SE, etc.).
| For gasoline engines - oil classes on the S scale | |||
| Oil group | Vehicle years | Qualitative indicators | |
| S.N. | Introduced in October 2010 This is the last service category for cars with gasoline engines. This new North American standard replaces the previous service category SM, which was introduced in 2004. Motor oils meeting API SN can be used in engines specified in API SM and earlier service categories S. API SN oils are improvements over API SM in areas of oxidative stability and deposit and sludge control. API has also introduced a new designation, "Resource Conserving", which can be used in conjunction with API SN. The “Resource Conserving” designation replaces the previous “Energy Conserving” designation. While the "Energy Saving" designation was focused only on fuel economy, the new "Resource Saving" designation covers fuel economy, aftertreatment and turbo protection, and compatibility with ethanol containing fuels (up to E85, i.e. . with fuels containing up to 85% bioethanol). In other words, the main difference between API SN and previous API classifications is the limitation of phosphorus content for compatibility with modern exhaust gas aftertreatment systems, as well as comprehensive energy saving. That is, oils classified according to API SN approximately correspond to ACEA C2, C3, C4, without correction for high-temperature viscosity. | since 2011 | - |
| S.M. | Introduced in November 2004. Technological development trends are aimed at increasing their environmental safety, increasing maintenance intervals while maintaining operational reliability. Naturally, this makes adjustments to the process of improving engines, affecting the quality of lubricants. Following these trends, in November 2004, the API classification introduced a class for motor oils for gasoline engines - SM, which, compared to SL, implies increased requirements for lubricants regarding oxidation resistance, protection against deposits, wear, etc. Since October 2006, the category for diesel oils has been expanded to include class CJ-4. |
since 2004 | - |
| SL | (Current). API planned to develop Project PS-06 as the next API SK category, but one of the motor oil suppliers in Korea uses the abbreviation "SK" as part of its corporate name. To avoid possible confusion, the letter "K" will be omitted for the next category "S". - stability of energy-saving properties; - reduced volatility; - extended replacement intervals. |
since 2001 | - |
| S.J. | (Current). The category was approved on November 6, 1995, licenses began to be issued on October 15, 1996. Automotive oils of this category are intended for all currently used gasoline engines and completely replace oils of all previously existing categories in older engine models. Maximum level of performance properties. Possibility of certification according to the energy saving category API SJ/EC. | since 1996 | - |
| SH | (Conditionally valid). Licensed category approved in 1992. Today, 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 complies with the ILSAC GF-1 category, but without mandatory energy saving. Automotive oils in this category are intended 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. |
| S.G. | Licensed category approved in 1988. The issuance of licenses ceased at the end of 1995. Automotive oils are intended for engines of 1993 and older models. Fuel - unleaded gasoline with oxygenates. Meets the requirements for automotive oils for diesel engines of API CC and API CD categories. They have higher thermal and antioxidant stability, improved anti-wear properties, and a reduced tendency to form deposits and sludge. API SG automobile oils replace oils of the API SF, SE, API SF/CC and API SE/CC categories. |
1989-1993 | |
| SF | Automotive oils in this category are intended for engines of 1988 and older models. Fuel - leaded gasoline. They have more effective antioxidant, anti-wear, anti-corrosion properties than previous categories and are less prone to the formation of 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 | |
| S.E. | Highly accelerated engines operating in difficult conditions. | 1972-1980 | higher |
| SD | Medium-boosted engines operating in difficult conditions. | 1968-1971 | average |
| S.C. | Engines operating under increased loads. | 1964-1967 | - |
| S.B. | Motors operating under moderate loads are used only at the request of the manufacturer. | - | - |
| S.A. | 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 application | Vehicle years | Qualitative indicators |
| CJ-4 | Introduced in 2006. For high-speed four-stroke engines designed to meet the 2007 highway emissions regulations. CJ-4 oils allow the use of fuel with a sulfur content of up to 500 ppm (0.05% by weight). However, operation with fuels containing sulfur content greater than 15 ppm (0.0015% by weight) may affect the performance of aftertreatment systems and/or oil change intervals. CJ-4 oils are recommended for engines equipped with diesel particulate filters and other exhaust gas treatment 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. |
since 2006 | - |
| CI-4 | Introduced in 2002. For high-speed four-stroke engines designed to meet 2002 emissions regulations. CI-4 oils allow the use of fuel 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 have been tightened, and the TBN value has been limited. |
since 2002 | - |
| CH-4 | Introduced in 1998. For high-speed four-stroke engines that meet emission standards introduced in the United States since 1998. CH-4 oils allow the use of fuel 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 running on fuel with a sulfur content of less than 0.5%. CG-4 oils for engines meeting exhaust emissions requirements introduced in the USA since 1994. Replaces oils of CD, CE and CF-4 categories. | since 1995 | higher for models since 1995 |
| SF-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 |
| SF-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 higher. Replaces CD oils. | since 1994 | - |
| C.E. | Highly advanced, highly turbocharged engines operating under severe conditions can be used instead of CC and CD class oils. | since 1987 | higher |
| CD | A class of oils for high-speed diesel engines with turbocharging and high specific power, operating at high speeds and at high pressures and requiring increased anti-fouling properties and prevention of soot formation. | since 1955 | average |
| CC | Highly boosted engines (including moderately boosted ones) operating in difficult conditions. | since 1961 | low |
| C.B. | Medium-boosted, naturally aspirated engines operating at increased loads on sulfur fuel. | 1949-1960 | - |
| C.A. | Engines operating under moderate loads on low-sulfur fuel. | 1940-1950 | - |
Universal oils for gasoline engines and diesel engines they have designations of both categories, for example API SG/CD, API SJ/CF.
Diesel oil classes are further subdivided for two-stroke(CD-2, CF-2) and four-stroke diesel engines (CF-4, CG-4, CH-4).
API Signs
Oils that meet the requirements of current quality categories and have passed official API - SAE tests have a graphic round sign (donut mark) on their labels - "API service symbol" ( API Service Symbol), which indicates the viscosity grade according to SAE, quality category and purpose according to API and the possible degree of energy saving.
Oils licensed by API and meeting API SN are indicated on the rear label with the API service symbol “ring”. Information that the licensed oil also meets the Resource Conserving designation is shown on the bottom of the ring.
The newest categories of oils certified by API, in case of compliance with ILSAC requirements, are indicated by the “API Certification Certificate Symbol” (), the so-called “Starburst” mark. This mark can only be assigned to energy-saving, easy-flowing oils of the highest quality level, with SAE viscosities 0W-..., 5W-... and 10W-.... The ILSAC GF series oil requirements system is part of the API American Oil Quality Assurance System (EOLCS).
API - ILSAC systems are designed to meet the requirements for oils used in American and Japanese car engines. The requirements of European automakers are somewhat different due to the design features of European engines. Despite this, most motor oils entering the European market are marked with API quality marks and, in rare cases, even with the API Service Symbol.
The API classification system for motor oils () was created in 1969. According to the API system, three operational categories (three rows) are established for the purpose and quality of motor oils:
S (Service)- consists of quality categories of motor oils for gasoline engines, in chronological order.
C (Commercial)- consists of categories of quality and purpose of oils for diesel engines, in chronological order.
EC (Energy Conserving)- energy-saving oils. A new range of high-quality oils, consisting of low-viscosity, easy-flowing oils that reduce fuel consumption according to test results on gasoline engines.
For each new class, an additional letter of the alphabet is assigned. 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 a different type of engine. Example: API SM/CF.
API quality classes for gasoline engines
API class SN– approved on October 1, 2010.
The main difference between API SN and previous API classifications is the limitation of phosphorus content for compatibility with modern exhaust gas aftertreatment systems, as well as comprehensive energy savings. That is, oils classified according to API SN will approximately correspond to ACEA C2, C3, C4, without correction for high-temperature viscosity.
API class SM– approved on November 30, 2004.
Motor oils for modern gasoline (multi-valve, turbocharged) engines. Compared to the SL class, motor oils that meet API SM requirements must have higher protection against oxidation and premature wear of engine parts. In addition, standards regarding the properties of oil at low temperatures have been raised. Motor oils of this class can be certified according to the ILSAC energy efficiency class
Motor oils that meet the requirements of API SL, SM can be used in cases where the car manufacturer recommends class SJ or earlier.
API SL class– motor oils for engines of cars manufactured after 2000.
In accordance with the requirements of car manufacturers, motor oils of this class are used in multi-valve, turbocharged engines running on lean fuel mixtures that meet modern increased environmental and energy saving requirements. Motor oils that meet API SL requirements can be used in cases where the car manufacturer recommends class SJ or earlier.
API class SJ– motor oils for use in gasoline engines starting from 1996.
This class describes motor oils that are used in gasoline engines starting from 1996. Motor oils of this class are intended for use in gasoline engines of passenger cars and sports cars, minibuses and light trucks, which are maintained in accordance with the requirements of car manufacturers. SJ has the same minimum standards as SH, plus additional requirements for carbon formation and low temperature operation. Motor oils that meet API SJ requirements can be used in cases where the vehicle manufacturer recommends class SH or earlier.
API class SH– motor oils for gasoline engines starting from 1994.
The class was adopted in 1992 for motor oils recommended since 1993. This class is characterized by higher requirements compared to the SG class, and was developed as a substitute for the latter to improve the anti-carbon, antioxidant, anti-wear properties of oils and increased corrosion protection. Motor oils of this class are intended for use in gasoline engines of passenger cars, minibuses and light trucks, in accordance with the recommendations of their manufacturers. Motor oils of this class were tested in accordance with the requirements of the Chemical Manufacturers Association (CMA). Motor oils of this class can be used in cases where the vehicle manufacturer recommends class SG or earlier.
API class SG– motor oils for gasoline engines starting from 1989.
Designed for use in gasoline engines of passenger cars, minibuses and light trucks. Motor oils of this class have properties that provide improved protection against soot, oil oxidation and engine wear, compared to previous classes, and also contain additives that protect against rust and corrosion of internal engine parts. Motor oils of the SG class meet the requirements for motor oils for diesel engines API CC and can be used where classes SF, SE, SF/CC or SE/CC are recommended.
API class SF- motor oils for gasoline engines since 1980 (obsolete class).
These motor oils were used in gasoline engines produced in 1980-1989, subject to the recommendations and instructions of the engine manufacturer. They provide enhanced oxidation stability, improved protection against wear of parts, compared to the basic characteristics of SE motor oils, as well as more reliable protection against soot, rust and corrosion. Motor oils of the SF class could be used as substitutes for the previous classes SE, SD or SC.
API SE class- motor oils for gasoline engines manufactured 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 class- motor oils for use in gasoline engines since 1968 (obsolete class). Motor oils of this class were used in gasoline engines of passenger cars and some trucks produced in 1968-70, as well as some models of 1971 and later. Improved protection compared to SC motor oils, also used only if recommended by the engine manufacturer.
API SC class- motor oils for gasoline engines, starting from 1964 (obsolete class). Typically used in engines of passenger cars and some trucks produced in 1964-1967. Reduce high- and low-temperature carbon deposits, wear, and also protect against corrosion.
API class SB- motor oils for low-power gasoline engines (outdated class). Motor oils of the 30s of the 20th century, which provided fairly light protection against wear and oxidation, as well as anti-corrosion protection of bearings in engines operated under light load conditions. Motor oils of this class can only be used if they are specifically recommended by the engine manufacturer.
API SA class- motor oils for gasoline and diesel engines. An obsolete class of oils for use in old engines operating in conditions and modes in which protection of parts with the help of additives is not necessary. Motor oils of this class can only be used if they are recommended by the engine manufacturer.
API quality classes for diesel engines
API class CJ-4- valid from October 1, 2006.
This class is designed specifically for heavily loaded engines. Meets key NOx and particulate matter emissions standards for 2007 engines. Limits are introduced for CJ-4 oils for certain indicators: ash content less than 1.0%, sulfur 0.4%, phosphorus 0.12%.
The new classification accommodates the requirements of the earlier API categories CI-4 PLUS, CI-4, but carries significant changes to the requirements in response to the needs of new engines that meet the new environmental standards of 2007 and later models.
API Class CI-4 (CI-4 PLUS)- a new performance class of motor 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, motor oil must be tested in seventeen motor tests.
API class CI-4- the class was introduced in 2002.
These motor oils are used in modern diesel engines with various types of injection and supercharging. Motor oil corresponding to this class must contain appropriate detergent-dispersant additives and, in comparison with the CH-4 class, has increased resistance to thermal oxidation, as well as higher dispersing properties. In addition, such motor oils provide a significant reduction in engine oil waste by reducing volatility and reducing evaporation at operating temperatures up to 370°C, under the influence of gases. The requirements regarding cold pumpability have also been strengthened, the service life of clearances, tolerances and engine 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 gas toxicity, which are imposed on engines manufactured from October 1, 2002.
API class CH-4- effective from December 1, 1998.
Motor oils of this class are used in four-stroke diesel engines that operate in high-speed modes and comply with the requirements of exhaust gas toxicity norms and standards adopted in 1998.
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 fuel with a specific sulfur content of up to 0.5%. At the same time, in contrast to 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. Can be used as a substitute for API CD, API CE, API CF-4 and API CG-4 motor oils in accordance with the engine manufacturer's recommendations.
API class CG-4- class introduced in 1995.
Motor oils of this class are recommended for four-stroke diesel engines of buses, trucks and tractors of main and non-mainline types, which are operated under high load conditions, as well as high-speed modes. API CG-4 engine oil is suitable for engines that use high-quality fuel with a specific sulfur content of no more than 0.05%, as well as for engines for which there are no special requirements for fuel quality (specific sulfur content can reach 0.5% ).
Motor oils certified to API CG-4 should more effectively prevent wear of internal engine parts, carbon deposits on internal surfaces and pistons, oxidation, foaming, and soot formation (these properties are especially needed for engines of modern long-haul buses and tractors).
The API CG-4 class was created in connection with the approval in the USA of new requirements and standards for ecology and toxicity of exhaust gases (1994 edition). Motor oils of this class can be used in engines for which API CD, API CE and API CF-4 classes are recommended. The main drawback limiting the mass use of motor oils of this class, for example in Eastern Europe and Asia, is the significant dependence of the life of the motor oil on the quality of the fuel used.
API Class CF-2 (CF-II)- motor oils intended for use in two-stroke diesel engines that are operated 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 heavy load conditions. API CF-2 oils must contain additives that provide enhanced performance protection against wear on internal engine components such as cylinders and rings. In addition, these motor oils should prevent the accumulation of deposits on the internal surfaces of the engine (improved cleaning function).
Engine oil certified to API CF-2 has improved properties and can be used instead of earlier similar oils, subject to the manufacturer's recommendation.
API class CF-4- motor oils for use in four-stroke diesel engines starting from 1990.
Motor oils of this class can be used in four-stroke diesel engines, the operating conditions of which are associated with high-speed modes. For such conditions, the quality requirements for oils exceed the capabilities of the CE class, so CF-4 motor oils can be used instead of CE class oils (subject to appropriate recommendations from the engine manufacturer).
API CF-4 motor oils must contain appropriate additives that provide reduction in oil burnout, as well as protection against carbon deposits in the piston group. The main purpose of motor oils of this class is to use them in diesel engines of heavy-duty tractors and other vehicles that are used for long trips on highways.
In addition, such motor oils are sometimes assigned a dual API CF-4/S class. In this case, subject to the appropriate recommendations from the engine manufacturer, these motor oils can also be used in gasoline engines.
API class CF (CF-2, CF-4)- motor oils for diesel engines with indirect injection. Classes were introduced from 1990 to 1994. The number separated by a hyphen indicates a two- or four-stroke engine.
Class CF describes motor oils recommended for use in diesel engines with indirect injection, as well as other types of diesel engines that run on fuel of various qualities, including those with a high sulfur content (for example, more than 0.5% of the total mass).
CF certified motor oils contain additives to better prevent piston deposits, wear and copper bearing corrosion, which is essential for these types of engines, and can be pumped conventionally or via a turbocharger. or compressor. Motor oils of this class can be used where CD quality class is recommended.
API class CE- motor oils for use in diesel engines starting from 1983 (obsolete class).
Motor oils of this class were intended for use in some heavy-duty turbocharged engines, characterized by significantly increased operating compression. The use of such oils was allowed for engines with both low and high shaft speeds.
API CE engine oils were recommended for low- and high-speed diesel engines manufactured since 1983, which were operated under high load conditions. Subject to the appropriate recommendations from the engine manufacturer, these motor oils could also be used in engines for which CD class motor oils were recommended.
API class CD-II- motor oils for use in heavy-duty diesel engines with a two-stroke operating cycle (obsolete class).
The class was introduced in 1985 for use in two-stroke diesel engines and is, in fact, an evolutionary development of the previous API CD class. The main purpose of using such motor oils was to use them in heavy, powerful diesel engines, which were installed mainly on agricultural machinery. Motor oils of this class meet all operating standards of the previous CD class; in addition, the requirements for highly effective engine protection against soot and wear have been significantly increased.
API CD class- motor oils for high-power diesel engines that were used in agricultural machinery (obsolete class). The class was introduced in 1955 for normal use in some diesel engines, both naturally aspirated and turbocharged, with increased cylinder compression, where effective protection against soot and wear is extremely important. Motor oils of this class could be used in cases where the engine manufacturer did not impose additional requirements for fuel quality (including fuel with a high sulfur content).
API CD motor oils were supposed to provide increased protection against bearing corrosion and high-temperature carbon deposits in diesel engines compared to previous classes. Motor oils in this class were often called “Caterpillar Series 3” due to the fact that they met the requirements of the Superior Lubricants (Series 3) certification developed by the Caterpillar tractor company.
API class CC- motor oils for diesel engines that are operated under medium load conditions (obsolete class).
The class was introduced in 1961 for use in certain engines, both naturally aspirated and turbocharged, which were characterized by increased compression. Motor oils of this class were recommended for engines operated under moderate and high load conditions.
In addition, subject to the recommendations of the engine manufacturer, such motor oils could be used in some powerful gasoline engines.
Compared to earlier classes, API CC motor oils were required to provide a higher level of protection against high-temperature carbon deposits and bearing corrosion in diesel engines, as well as against rust, corrosion and low-temperature carbon deposits in gasoline engines.
API class SV- motor oils for diesel engines operating under medium load (obsolete class).
The class was approved in 1949 as an evolutionary development of the SA class using fuel with a high sulfur content without special quality requirements. API SV motor oils were also intended for use in supercharged engines that were operated in light and moderate modes. This class was often referred to as “Appendix 1 Motor Oils,” thereby emphasizing compliance with military regulations MIL-L-2104A Appendix 1.
CA API class- motor oils for lightly loaded diesel engines (obsolete class).
Motor oils of this class are intended for use in diesel engines operating in light and moderate 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 specified by the engine manufacturer.
API CA motor oils must have properties that provide protection against carbon deposits on piston rings, as well as against corrosion of bearings in supercharged engines, for which there are no special requirements for the quality of the fuel used.
