One observation about amsoil,
amsoil series 2000 5-30 runs high in viscosity range. I have
confirmed this in my own oil analysis test. I don't think
its appropriate for our 5-20 motor, except southern climates can probably
run it ok in the summer.
I got an email from amsoil, a 0-20 series 2000 is in development.
I will have to run amsoil XL7500 0-20 for now.
This is a long term test that is very interesting, nothing like this
exists anywhere else.
I think this is keypoint of the analysis.
Wear metals at Miles 9000
____________Mobil 1______Amsoil
Iron___________38_________17
Copper________124_________69
Lead__________16__________12
Another is that if running
extended drain like 10k miles, a filter change at 5 k miles will
drop the wear metals.
http://neptune.spacebears.com/cars/s.../oil-life.html
http://neptune.spacebears.com/cars/stories/mobil1.html
http://neptune.spacebears.com/cars/stories/amsoil.html