Originally Posted By: glxpassat
Note that Delvac 1 meets the E4 spec which is a very severe heavy duty rating, and from Doug Hillary we know it is a group 4/5 oil. The Delvac ESP does not meet that spec, therefore it is more likely to be blended with group 3.
I would suspect all 4 listed are a group 3/4 blend.
One (if not the only) reason why D1 ESP does not meet ACEA E4 is the TBN 12 or higher requirement of the current E4-08 spec. The latest Mercedes Benz 228.5 spec. asks for the same. With its TBN 10.1, D1 ESP cannot meet these spec., but might still pass the required engine tests with flying colors. The trickiest part of E4 and MB228.5 is to achieve the required piston cleanliness in the MB OM441LA test engine, which is now replaced by the OM501LA. However, one can still meet E4-08 via OM441LA test results and to my information, the MB OM441LA is the engine that is currently used to qualify for an MAN M3277 approval with the same piston cleanliness limit as for E4 or an MB228.5 approval. MAN M3277 oils actually have to meet at least ACEA E4-99. Since D1 ESP is an MAN M3277 approved lubricant, it will meet ACEA E4-99 as well as the engine test requirements of ACEA E4-08. As for wear protection, ACEA E7 is more damanding than E4. Whether D1 ESP passes all MB228.5 engine tests, is something only MB and Mobil can tell. I have yet to figure out whether the new OM501LA test engine must be used to get a current MB approval for a new lubricant.