Description:
7 min
Choosing engine oil according to API specification
To select the correct engine oil, you must be able to read and understand the markings on the package. Choosing the wrong type of lubricant or using engine oil that is not suitable for your engine over the long term can lead to engine breakdown.
One of the most common and generally accepted classifications of motor oils is the API specification from the American Petroleum Institute (API). More than 80% of the products on the motor oil market meet this specification, which is marked on packages as API SN, API CF, and so on.
Traditionally, API specification is divided into two broad categories: S for engines that use gasoline as fuel, and C for diesel engines.
New energy-saving oils have also been introduced under the EU category.
Oils that meet the current quality categories and have passed official API and SAE tests feature a round graphic sign (known as the "API Service Symbol" or "donut mark") on their labels. This symbol indicates the oil's viscosity level (per SAE classification), quality category, intended use according to API, and potential energy-saving capabilities (per EU standards).
For gasoline engines, S specification engine oil is recommended. However, it is important to choose the correct viscosity level and quality category based on the manufacturer's recommendations and the API Service Symbol on the oil's label.
S specification engine oil (gasoline engines)
SP entered into force on May 1, 2020. Resource-saving oils will enable vehicles to meet fuel economy standards and provide superior turbocharger protection for use in current and future engines, including engines designed to run on ethanol fuels up to E85. The oils are formulated to provide protection against low-speed pre-ignition, a phenomenon common to turbocharged direct injection (GDI) gasoline engines. Engine oils of the SP specification are available in the catalog.
SN Plus, approved on May 1, 2018, includes all the benefits of API SN, but with added protection against pre-ignition of the mixture at low speeds. Engine oils of the SN Plus specification are available in the catalog.
SN, approved on October 1, 2010, is the modern class of motor oils that meet high environmental requirements and have good performance characteristics that help protect the engine. API SN has one significant difference from previous generation oils: the percentage of phosphorus in the composition is reduced, and properties are increased to help significantly reduce fuel consumption. The main difference between API SN and previous API classifications is the limitation of phosphorus content for compatibility with modern exhaust gas after-treatment systems, as well as comprehensive energy savings. Engine oils of the SN specification are available in the catalog.
SM, approved on November 30, 2004, is for modern gasoline (multi-valve, turbocharged) engines. Compared to the SL class, engine oils that meet the requirements of API SM must have higher levels of protection against oxidation and premature wear of 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 meeting the requirements of API SM can be used in cases where SL or earlier is recommended by the vehicle manufacturer. Engine oils of the SM specification are available in the catalog.
SL is intended for use in engines manufactured in accordance with the requirements for environmental friendliness in 2000. It has improved properties and can also reduce fuel consumption. 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 savings. Oils that meet the requirements of API SL can be used in cases where the SJ or earlier class is recommended by the automaker. Engine oils of the SL specification are available in the catalog.
SJ oil of this class is still valid to this day. It was first certified in 1995 and is designed for servicing cars, small trucks, and minibusses. Improved properties help protect the engine from corrosion, oxidation, and wear. It can replace the greases of previous classes. Engine oils of the SJ specification are available in the catalog.
SH is a class that has been certified and has been formally valid since 1993. The composition with improved performance characteristics is able to protect the engine from the oxidation of metal parts and the formation of accumulations of combustion products on the inner walls of the power unit. It contains a set of additives that contribute to the long operation of the car. It can replace previous classes. Today, it is used according to the manufacturer's recommendation. Engine oils of the SH specification are available in the catalog.
SG was valid from 1988 to 1995, and lubricants of this category were used in engines that used unleaded gasoline as fuel. The composition contains additives that protect the metal parts of the engine from corrosion. Engine oils of the SG specification are available in the catalog.
SF has improved performance compared to SE oil and provides protection against wear, oxidation, and carbon deposits. It was used in cars from 1981-1989
Specification C engine oil (diesel engines)
Classes CA, CB, CC, CD, and CE (and their modifications) are now considered obsolete and can only be applied if there is a recommendation from the car manufacturer.
CK-4 (PC-11A) was introduced in 2016. It describes oils for use in high-speed, four-stroke diesel engines that meet the 2017 emission control standards for trucks and off-highway vehicles, as well as older diesel engines. These oils are formulated for use with low-sulfur diesel fuels (0.0015% - 0.05% by weight). The sulfur content of the fuel can affect the life of the exhaust after-treatment system and/or the oil change interval. CK-4 oils are recommended for engines equipped with Diesel Particulate Filters (DPF) and other after-treatment systems. They are compatible with all previous approvals. The engine oil specification CK-4 is available in the catalog.
FA-4 (PC-11B) was introduced on December 1, 2016. The engine oil of this class meets the highest requirements for the content of ash compounds for the latest high-speed, heavily loaded diesel engines of trucks and off-road vehicles manufactured in 2017 and later. FA-4 grade oils are low viscosity, resulting in better fuel economy. FA-4 lubricants are recommended for use in engines operating on fuels with sulfur content up to 15 ppm (0.0015% by weight). They are recommended for engines equipped with diesel particulate filters (DPF) and other after-treatment systems. FA-4 oils are not compatible with all previous tolerances as they are only approved for modern cars (manufactured from 2017 and later). They should be used in accordance with the recommendations of the vehicle manufacturer. The engine oil specification CJ-4 is available in the catalog.
CJ-4 was effective from October 1, 2006. It is a modern grade of commercial diesel engine oil for use in four-stroke engines designed to meet 2007 emission standards (EURO 5-6). CJ-4 oils are also recommended for engines equipped with diesel particulate filters (DPF) and other after-treatment systems. The engine oil specification CJ-4 is available in the catalog.
CI-4 PLUS was introduced as an additional category in 2004. The requirements for soot formation, deposits, and viscosity indicators have been tightened.
CI-4 has been effective since 2002. The oil of this specification has properties that meet many modern requirements. It is used in four-stroke engines designed to meet EURO 1-5 emission standards. It is characterized by increased resistance to temperature fluctuations and protects the power unit from wear, acidity, and carbon deposits. CI-4 oils are also used in engines equipped with exhaust gas recirculation (EGR) and selective catalytic reduction (SCR), without DPF particulate filters. The engine oil specification CI-4 is available in the catalog.
CH-4 complies with European and American environmental standards, meeting the requirements for exhaust toxicity since 1998 (e.g., EURO 1-4). It possesses increased working characteristics and is used in engines using fuel with a sulfur content of less than 0.5%. CH-4 oils can be used instead of CD, CE, CF-4, and CG-4 oils, and they are compatible with Exhaust Gas Recirculation (EGR) systems. The engine oil specification CH-4 is available in the catalog.
CG-4 meets the environmental requirements of the mid-1990s and has improved performance characteristics compared to CF-4. It is used in engines that operate on fuel with a maximum sulfur content of 0.5%. Although currently obsolete, it is still commonly used for classification purposes. Engine oil specifications for CG-4 can be found in the catalog.
CF-4 has been used since 1990 in 4-stroke diesel engines operating under heavy loads. It contains a set of additives that reduce fuel consumption and protect the cylinder-piston group from the formation of soot. Although currently obsolete, it is still commonly used for classification purposes. Engine oil specifications for CF-4 can be found in the catalog.