The American Petroleum Institute (API) is a trade association that represents the oil and natural gas industry. The API is responsible for developing and maintaining standards for the motor oil industry. These standards are designed to ensure that motor oils meet certain quality and performance requirements.
Key Facts
- API Service Symbol “Donut”: The API certifies motor oils with a service symbol known as the “Donut.” This symbol indicates that the oil meets specific quality and performance standards set by the API.
- Motor Oil Grades: The API classifies motor oils into different grades and categories based on their performance properties. These grades are designed to meet the requirements of different types of engines, including gasoline and diesel engines.
- Gasoline Engine Categories: For gasoline engines, the API has different service categories such as SP, SN, SM, SL, SJ, SH, SG, SF, SE, SD, SC, SB, and SA. Each category represents a specific level of performance and protection for different generations of automotive engines.
- Diesel Engine Categories: The API also has service categories for diesel engines, including CK-4, CJ-4, CI-4, and CH-4. These categories describe the performance and protection levels of motor oils for high-speed four-stroke cycle diesel engines.
- Compatibility: It’s important to note that not all motor oils are compatible with each other. For example, API FA-4 oils are not interchangeable or backward compatible with API CK-4, CJ-4, CI-4 PLUS, CI-4, and CH-4 oils. It’s essential to refer to the engine manufacturer’s recommendations to determine the suitable API category for your specific engine.
API Service Symbol “Donut”
The API certifies motor oils that meet its standards with a service symbol known as the “Donut.” The Donut is a circular symbol that contains the API logo and the API Service Category. The API Service Category is a code that indicates the type of engine that the oil is suitable for. For example, the API SP category is suitable for gasoline engines, while the API CK-4 category is suitable for diesel engines.
Motor Oil Grades
The API also classifies motor oils into different grades based on their viscosity. Viscosity is a measure of how easily oil flows. The higher the viscosity, the thicker the oil. The API grades motor oils on a scale from 0W to 60. The lower the number, the thinner the oil. The higher the number, the thicker the oil.
Gasoline Engine Categories
The API has different service categories for gasoline engines. The current categories are SP, SN, SM, SL, SJ, SH, SG, SF, SE, SD, SC, SB, and SA. Each category represents a specific level of performance and protection for different generations of automotive engines. For example, the API SP category is the latest category for gasoline engines and provides the highest level of protection.
Diesel Engine Categories
The API also has service categories for diesel engines. The current categories are CK-4, CJ-4, CI-4, and CH-4. These categories describe the performance and protection levels of motor oils for high-speed four-stroke cycle diesel engines. For example, the API CK-4 category is the latest category for diesel engines and provides the highest level of protection.
Compatibility
It’s important to note that not all motor oils are compatible with each other. For example, API FA-4 oils are not interchangeable or backward compatible with API CK-4, CJ-4, CI-4 PLUS, CI-4, and CH-4 oils. It’s essential to refer to the engine manufacturer’s recommendations to determine the suitable API category for your specific engine.
Conclusion
The API is a leading organization in the development and maintenance of standards for the motor oil industry. The API’s standards help to ensure that motor oils meet certain quality and performance requirements. The API also classifies motor oils into different grades and categories based on their performance properties. These grades and categories are designed to meet the requirements of different types of engines, including gasoline and diesel engines.
Sources
FAQs
What does API stand for in motor oil?
API stands for American Petroleum Institute.
What is the API Service Symbol “Donut”?
The API Service Symbol “Donut” is a circular symbol that contains the API logo and the API Service Category. The API Service Category is a code that indicates the type of engine that the oil is suitable for.
What are the different API Service Categories for gasoline engines?
The current API Service Categories for gasoline engines are SP, SN, SM, SL, SJ, SH, SG, SF, SE, SD, SC, SB, and S Each category represents a specific level of performance and protection for different generations of automotive engines.
What are the different API Service Categories for diesel engines?
The current API Service Categories for diesel engines are CK-4, CJ-4, CI-4, and CH-4. These categories describe the performance and protection levels of motor oils for high-speed four-stroke cycle diesel engines.
Are all motor oils compatible with each other?
No, not all motor oils are compatible with each other. For example, API FA-4 oils are not interchangeable or backward compatible with API CK-4, CJ-4, CI-4 PLUS, CI-4, and CH-4 oils.
How do I know which API Service Category is right for my engine?
You can find the recommended API Service Category for your engine in your vehicle’s owner’s manual.
Where can I find the API Service Symbol “Donut” on a motor oil container?
The API Service Symbol “Donut” is usually located on the front or back of the motor oil container.
What are some of the benefits of using motor oil that meets API standards?
Motor oil that meets API standards can help to:
- Protect your engine from wear and tear
- Improve your engine’s performance
- Extend the life of your engine
- Reduce your vehicle’s emissions