API classification

What API is, how to read the code, and which classes exist.

5 articles in the section, about 20 minutes of reading in total

  1. API Engine Oil Classification How the API classification of the American Petroleum Institute (1969) works: petrol and diesel classes, the marking on the label and what its absence means. 235 words, 2 min
  2. Decoding the API code How to read the API class on a label: S marks oil for petrol engines, C for diesels, and a double class such as SJ/CF-4 shows the oil’s main purpose. 114 words, 1 min
  3. What API classes are there? An overview of API classes for petrol and diesel engines: how often they are updated, what was added from SN to SQ and CK-4 to CL-4, and which are obsolete. 145 words, 1 min
  4. What engine oil quality classifications are there? How the API, ACEA, ILSAC and JASO classifications differ, which classes apply today, how they relate to approvals and why a newer class is not always better. 1 241 words, 7 min
  5. API SQ and ILSAC GF-7: what do the new classes on the can mean? What API SN, SP and SQ added, how the ILSAC GF-7A “starburst” differs from the GF-7B “shield”, where the diesel CK-4 and FA-4 stand, and why a class is only the minimum. 1 595 words, 9 min new article

Other subsections

API SN oils

All 208 oils rated API SN

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