Engine oil products that have the API category and ratings, including the S on their containers, have undergone the voluntary Engine Oil Licensing and Certification System - EOLCS from the API.

American Petroleum Institute (API) announced the approval of improved performance standards for engine oils that will provide greater protection and fuel efficiency for today’s gasoline-engine ...

These API engine oil categories, CJ-4 and CK-4, differ in their performance attributes, which contribute to a vehicle’s overall fuel economy and operating capacity.

With test parameters established for the proposed new oils, oil companies began developing formulations that would satisfy the new API standards and overcome the perceived shortcomings of CJ-4. During ...

The Product has obtained API (American Petroleum Institute) SP certification*1, making it the world's first*2 engine oil with racing performance*3 and API SP certification using a plant-based raw ...

Gen III then submitted its first Group III based 5 W-30 PCMO formulation and ReGen III product to API’ s Engine Oil Licensing and Certification System.

In February of last year, the American Petroleum Institute (API) engine oil committee designated the new API CJ-4 engine oil performance category to meet the requirements for 2007 on-highway ...

In order to meet the U.S. EPA's 2007 on-highway emission standards for particulate and NOx, all diesel engines will require diesel particulate filters (DPFs) and cooled exhaust gas recirculation (EGR) ...

There's a lot of information on the packaging for your engine's motor oil, but the S designation may be one of the most important to look for.