I have made the switch to NAPA filters after reading the list and actually
looking at the filters. But I'm still wondering about synthetic oil. If I
understand the general gist, it goes something like this: synthetic oil has
better flow at low temperatures, and works better at extremely high
temperatures. The one big advantage of a quality filter, like the NAPA gold is
that it has a valve which allows thick, cold oil to bypass the filter element
until the oil warms up. So, if I only use my van in the summer, is there any
real advantage to the synthetic oil, and if you change synthetic oil at 10,000
mile intervals instead of 3,000 mile intervals, aren't you just allowing for
more dirt particles ie...dirtier oil in the crankcase longer?