Bob: What you say about suspension is correct when relating to Mobil 1 and others. However there is only one pure synthetic oil. Amsoil is not formulated from a crude oil base as are the others. The others use a crude oil base refined to a clear liquid, but none the less, still a petroleum base. I agree that your statement regarding how good does good have to be, has merit, but Amsoil has a completely different chemical formulation that completely suspends carbon and lead deposits, which can be removed only through filtering. Of course filtering is the key to clean oil in any engine, and Amsoil's filters take the micron levels down significantly, but not enough to restrict flow pressure considerations. One can also use by-pass filter arrangements cleaning the oil up to the ONE MICRON LEVEL. This happens by running the oil through the by-pass filter at the 10% rate so as not to affect the oil pressure. At this writing, I do not know if any of this is Approved, but intend to find out. The real benefit as I see it, is the elimination of stuck valves, dry starts ( 80% wear factor), and reduced oil temp. If one is careful about the fuel they burn, proper leaning, and shut down procedures, most of the engine related problems could be greatly reduced. In my opinion, of course. Fly happy, Doug
<<attachment: winmail.dat>>
