Don,
Here is that link (different site than Bob's):
http://neptune.spacebears.com/cars/s.../oil-life.html
In this test, they did run Mobil 1 for a year, then AMSOIL for a year. Both "passed".
They ran the Mobil 1 first and racked up 18k miles in that year. They decided to change the filter at the 12k mark for the Mobil 1.
During the year they ran AMSOIL, they racked up 14k miles and didn't need a filter change.
The AMSOIL showed lower wear metals than the Mobil 1. That may be due to better AW additives, or due to being later in engine life. Jury is still out. They are retesting with Mobil 1 next month.
The AMSOIL did thicken to about a 40 weight which seems to be normal for AMSOIL 5w30 which runs at the high end of the vicosity range. Mobil 1 starts lower in the 30 weight band.
Bottom line is they just ran that engine for two years and 32k miles with one oil change at the one year mark.
