SN, SM, and SL refer to the API quality grades of gasoline engine oil. SN is the highest grade, SM is the second, and SL is the lowest. They represent the fuel economy, durability and cleanliness of gasoline engine oil respectively. The gasoline engine oil additive complex is a chemical additive added to gasoline engine oil to improve the quality and performance of the engine oil.
SN SM SL gasoline engine oil additive package is formulated for gasoline engines meeting SN, SM and SL performance specifications. This additive package is designed to meet the demanding requirements of modern engines and provide superior lubrication, protection and performance.
SN SM SL gasoline engine oil additive packages consist of synthetic base stocks, dispersant additives, multi-functional anti-corrosion and antioxidants, dispersants, foam inhibitors, detergents and anti-wear agents as well as other performance additives used in formulating gasoline engine oils.

Some key additives that may be included in this package include:
- Detergents and Dispersants: These additives help keep your engine clean by preventing the formation of deposits, sludge and varnish. They work by suspending and dispersing contaminants in the oil so that they can be removed by the oil filter.
- Anti-wear additives: These additives form a protective film on the metal surface to reduce friction and wear between moving parts. They help extend the life of your engine and reduce the risk of damage from metal-to-metal contact.
- Viscosity modifiers: These additives help control the viscosity of the oil to ensure it maintains optimal lubrication properties at different temperatures. They help improve fuel efficiency, reduce friction and provide better protection under varying operating conditions.
- Antioxidant additives: These additives help prevent oil from oxidizing and forming deposits and sludge. Their job is to scavenge free radicals and inhibit the chemical reactions that cause petroleum degradation.
- Corrosion Inhibitors: These additives help protect engine components from corrosion, which can be caused by acidic byproducts of combustion or moisture. They form a protective barrier on metal surfaces, preventing rust and other forms of corrosion.
- Foam inhibitors: These additives help reduce the formation of foam in the oil, which causes aeration and reduces the oil’s ability to provide proper lubrication. They help maintain oil film strength and improve lubrication efficiency.
- Friction modifiers: These additives help reduce friction between moving parts, improve fuel efficiency and reduce wear. They form a protective film on metal surfaces, reducing contact and friction.
The main performance characteristics of SN, SM, SL and gasoline engine oil additive complex include: improving fuel economy, reducing wear, reducing noise, cleaning the engine, anti-oxidation, etc. In addition, different grades of engine oil additive packages have their own unique characteristics. For example, SN grade engine oil additive complex has better fuel economy and turbocharger protection performance; SM grade engine oil additive compound focuses on protecting the engine and extending oil service life; while SL grade engine oil additive compound focuses on cleaning performance and Engine start protection.

Performance advantages:
- It has good performance in dispersing particles, suspending dirt, and preventing sludge and sediment.
- Professional dispersion chemistry helps disperse high temperature deposits.
- Excellent oxidation stability, high temperature viscosity index, high oil film strength and wear resistance.
- The possibility of paper mesh clogging and piston varnishing is low.
- Excellent protection against rust and corrosion during engine start-up and normal operation
- Improve high-temperature engine cleanliness, fuel consumption and fuel economy.
- Excellent friction and wear characteristics.
- Extreme pressure performance (EP) protection.
Applications SN SM SL engine oil is suitable for modern automotive turbine and naturally aspirated engines.
Specification
Engine oils are formulated with high-performance additives that meet the latest industry standards.
Including API SN, SM or SL, ACEA, ILSAC and other testing requirements.
Motor oils are designed to provide optimal performance for a variety of vehicles from different manufacturers.
Since the 1960s, with the rapid development of the automobile industry, the demand for gasoline engine oil additive compounds has been growing day by day. In order to meet the requirements of environmental protection and fuel efficiency, API grades have gradually become the standard for measuring engine oil quality. At present, SN grade engine oil has become the mainstream, while SM and SL grade engine oil also occupy a certain share of the market.

Gasoline oil additive complexes are widely used in various industries and equipment, such as automobiles, aviation, railways, ships and other transportation vehicles, as well as industrial and commercial machinery and equipment. In the automotive industry, gasoline engine oil additive packages are widely used in engine lubrication and protection to improve fuel efficiency, reduce wear and clean engines. In addition, the aviation and railway industries also use it for the lubrication and protection of critical equipment to ensure the normal operation and extend the service life of these equipment. In industrial and commercial machinery and equipment, gasoline engine oil additive complexes are used to meet the lubrication and protection needs of equipment and improve equipment efficiency and production capacity.
Gasoline oil additive packages play a key role in ensuring normal engine operation, improving fuel efficiency, reducing maintenance costs and extending equipment service life. Through the understanding and application of SN, SM, SL and other grades of gasoline engine oil additive complexes, equipment managers and drivers can better choose engine oil additives that suit their equipment and needs, providing strong support for stable operation and extended service life of the equipment. Assure. Therefore, gasoline engine oil additive complexes will still play an indispensable role in future development.
The designations SN, SM, and SL refer to the American Petroleum Institute (API) service categories for gasoline engine oils. Each category represents a set of specifications and performance requirements that engine oils must meet to provide adequate protection for modern gasoline engines. An additive package designed for SN, SM, and SL engine oils would include components that address the specific requirements of these service categories.
Here’s a brief overview of the SN, SM, and SL API service categories:
API SN:
- API SN is the latest service category as of my last knowledge update in January 2022.
- It includes more stringent requirements compared to the previous categories and addresses the needs of modern engines, especially those with turbochargers and direct injection.
- Oils meeting the API SN specification provide enhanced protection against low-speed pre-ignition (LSPI), wear, and deposits.
API SM:
- API SM is an earlier service category that includes specifications for protecting engines against deposits, wear, and sludge.
- It was introduced to address the requirements of engines with variable valve timing (VVT) systems and other advancements.
API SL:
- API SL is an older service category and is designed to meet the needs of engines built in the early 2000s.
- It provides protection against deposits, wear, and sludge formation in engines.
An additive package for SN, SM, and SL engine oils would typically include a combination of additives to meet or exceed the specified performance requirements. The specific components in the additive package may include:
- Detergents and Dispersants: To keep the engine clean by preventing the formation of deposits and sludge.
- Anti-Wear Agents: To reduce friction and wear on engine components.
- Anti-Oxidants: To inhibit oxidation and extend the oil’s life by preventing the formation of harmful by-products.
- Viscosity Index Improvers (VII): To ensure stable viscosity across a range of temperatures.
- Pour Point Depressants: To improve low-temperature fluidity.
- Friction Modifiers: To enhance fuel efficiency by reducing friction.
- Corrosion Inhibitors: To protect metal surfaces from corrosion.
- Foam Inhibitors: To minimize foam formation during operation.
It’s important to note that the formulation of additive packages can vary among lubricant manufacturers, and the exact composition is often proprietary information. Lubricant formulators carefully design additive packages to meet the specified API service category and deliver optimal performance for gasoline engines. If you are looking for an additive package for SN, SM, or SL engine oils, it is recommended to consult with lubricant additive suppliers or manufacturers to ensure compatibility and performance.
An SN SM SL Gasoline Engine Oil Additive Package is a concentrated mixture of chemicals that are added to base oil to improve the performance and protect gasoline engines.
These SN SM SL Gasoline Engine Oil Additive Packages are designed to meet or exceed the API SN, SM, and SL performance standards. These standards were introduced in 2010, 2004, and 2001, respectively, for gasoline engines. They offer improved wear protection, oxidation resistance, and sludge control compared to earlier API categories.
However, it’s important to note that these are older standards and have been superseded by more recent ones like API SP and ILSAC GF-6. These newer standards offer even better performance and protection for modern gasoline engines.
Here are some things to keep in mind when using SN SM SL Gasoline Engine Oil Additive Packages:
- Always follow the manufacturer’s instructions carefully. Adding too much additive can actually harm your engine.
- Only use additives that are compatible with your engine oil. Mixing incompatible additives can lead to sludge formation and other problems.
- Consider whether an additive is really necessary. Modern engine oils already contain a variety of additives, so you may not need to add any more.
- Be aware of the potential risks of using additives. Some additives can increase emissions or shorten the lifespan of your engine oil.
If you are considering using an SN SM SL Gasoline Engine Oil Additive Package, it is important to weigh the potential benefits and risks carefully. Talk to your mechanic or consult your owner’s manual for more information.
I hope this information is helpful! Let me know if you have any other questions.

