Just did a search and found this thread. I am a bit confused about my oil pressure. As you may have read on my other topic, (getting little/no response).

I have been concerned about my oil pressure gauge readings. I changed the oil after I got the car, the oil was very dirty and the filter was shot and literally had a big hole in the side of it. I put in new oil and a new oil filter and initially, the readings seemed to be the same, if not slightly better- which seems normal. I have been reading that it (gauge) should be at "3" bar by 3000 rpms, but mine is at the "3" bar at about 1700 rpms and it at about "2.8" bar at 1500 rpms when the engine is around 85*C. My concern is when it is at idle, in gear, when the temperature is above 80*C. Today, it was nearly at "0" when it was idling in gear when the engine was hot. When I placed it in park it went to about .3 bar. Before it seemed to me like the pressure was better before I changed the old oil out. I may be wrong. I checked the oil level and it is fine. I also used 15W-40 as recommended by the owners manual. I did use a "purolator" oil filter however. Could this be the problem, or is my engine worn out? Should I put in an additive? Should I go with a thicker oil and a MB filter?

It is a 3.8L V8, with 264K. It still does not smoke, or burn oil, so I guess that is a plus.

Thanks for any advice.