I am about to change the oil on my wife's 2002 Montero that has about 160,000 miles on it. We bought it with 150,000 on it so this will be my second oil change. I put PU 5W30 last time and wanted to know why I would choose one over another. Mobil1 is so much easier to find than the other 2. I think my local walmart still carries the PU though. I would be using the M1 Extended performance most likely. I love Amsoil products but they are harder to get especially if you need some to top off and are out. I usually let the oil changes go about 10,000 miles maybe more and to date have not done any oil analysis but that may be in my future.