Generally, API adopts ILSAC specs when there's a spec change. SL is equal to GF-3 except in some non-energy conserving viscosities.
ACEA sets their own specs, and roughly speaking, A1 is about equal to API-SL (and SL is the floor for everything), A2 is old fashioned, A3 is tops, there's no A4, and A5 is not as robust as A3 but more energy saving.
Daimler-Chrysler starts with A3 for most of their oil spec and in some cases has requirements above that. (there's a link to oil that qualify for the different MB specs, but I've lost it).
There are many, many details I've left out, and hopefully someone will fill them in.
quote:Originally posted by vaphilly:
The detailed tests for all of them can be found in the following link...
I am not sure how meaningful all these tests are..
and if they can trully distinguise between bad and good oils....
That's a great link man. It is my strong opinion that some of the tests are very applicable in the real world since they essentially are real world tests. The DHD-1 test includes a used oil analysis after running the test oil in a Mack engine, lead has to be less than 15ppm. Doesn't get any more real than that.
European OEM specs will typically use the ACEA "A3/B4" spec as a starting point, then add manufacturer specific tests. For example, VW 502/505 starts with ACEA A3/B4 and then adds high temp testing in the 2.0L gas engine and wear testing in the 1.6L, IDI diesel engine. So I would look for OEM specs like DB 229.3, BMW Longlife, VW 502/505, etc in addition to the more generic ACEA A3/B4.
I would consider any ACEA, A3/B4 rated oil to be significantly better than your garden variety API, "SL" formulation.
For HD diesel oils, the Mack EON, Premium Plus and Cummins CES 20078 are probably the most stringent specs to meet. They are above and beyond the generic API, CI-4 specification ....