It was time for another oil change for me. I've got to say, the honeymoon is over. I crawled underneath it and found my oil pan was covered in oil. Last time it was changed, I had the dealer do it. They told me they changed the drain plug because they couldn't just change the oring. I personally find this to be crap, but hey, why would you want to insert logic into an argument with a dealer? I believe the oring should be changed at every OCI, but I couldn't find out what size I would need until I dropped the oil plug again. I mic'ed the oring and the slot it fits in, and found some interesting #'s. The oring measure 20x24, 2mm dia. The SLOT measured 19x24, 2.5mm recess. So now the question is, which should I go with, the 19mm or 20mm? I'll buy both if I can find it locally.