Very interesting post. I think Ive learned a lot. I have a question more or less related to the theme. If you switch from syntetic to regular oil, is there any configuration to do to the DIC when resetting the Oil Life Monitor? This will be the bonnie'* first oil change with us, and my dad told me he is going to use regular oil (we've used it on all our cars without any problems).
I've used Mobil 1 synthetic since I've owned the car (29,000 miles, now at 50,000). When we took it apart to do the cam the lifter valley looked like brand new and I've never had a valve cover or oilpan leak. I change the oil when the DIC is at about 20-25 percent which is about 5000 miles give or take a few hundred.