Decoding the API code

Section API classification, article 2 of 3114 words, 1 minute

What do the symbols in the API code mean?

In this section: 3 articles
  1. API Engine Oil Classification
  2. Decoding the API code
  3. What API classes are there?

The alphanumeric code denotes the oil's class. Here, the first letter of the code indicates the type of oil:

"S" - automotive oils for petrol engines;

"C" - oil for a diesel engine.If an engine oil can be used in both engine types, it's given two classes — one for diesel and one for petrol engines. On the oil's label these classes are separated by a forward slash — for example, API SJ/CF-4. Here, the class listed first is the one that matches the more priority application (in the automotive oil manufacturer's view). That is, in the example above, the oil's primary purpose is for petrol engines, but the manufacturer also permits its use in diesel engines.