What API classes are there?

What API oil classes are there, and how many of them?

In this section: 5 articles
  1. API Engine Oil Classification
  2. Decoding the API code
  3. What API classes are there?
  4. What engine oil quality classifications are there?
  5. API SQ and ILSAC GF-7: what do the new classes on the can mean?

Technology never stands still, and every year car manufacturers put forward more and more new requirements for engine oils. That's why the oil classes are regularly updated, once every few years. At the time this article was written, the following classes existed:

Engine oils for petrol engines

Engine oils for diesel engines