I have been running PP since I bought my car used on 10/07. I recently had my oil pan gasket replaced under the GM Certified powertrain warranty. Since the oil was due for a change anyway, I wasn't worried about losing that oil, but now I'm a little worried about what kind of oil they used. I know the filter is a Valvoline which according to the forums is probably made by Champion Labs, so no worries there. Here's my situation... I want to switch back, but I'm afraid if the oil leak is elsewhere, and the pan didn't fix it, then they may have to redo something and drain my oil again. Do you think the "dealer mystery oil" is ok for now? What would you do? Also, does anyone have any suggestions of the best way to remove all the old oil residue from the leak? I want to make sure I can spot fresh oil if the leak continues.