Babyhog,
Magnets are used on oil filters to remove fine bits of ferrous metal that would otherwise circulate in the oil. The idea is explained in detail here.
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1197231468/0===============
Please excuse Bill, he is a little bit grumpy from losing another oil war again. Bill is a fan of Klotz oil, but he can't show that it is better than the other contenders, just more expensive.
Bill doesn't lose very gracefully, so you can expect a stream of one liners that will attempt to derail other discussions. Bill unfortunately likes to throw out incorrect information intentionally in an attempt to confuse and irritate once he starts to lose.
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Verslagen is attempting an experiment to see if a thicker synthetic oil will help his oil consumption issues. He is reporting set up data, that the thicker oil doesn't change operating temperature conditions in any meaningful fashion. What this has to do with diesel oil and sump capacity aka Bill, who knows? Verslagen is changing over from Rotella Syn 5w40 to Mobil 1 Syn 20w50 and he is reporting what he sees with this change.
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Babyhog? What does the name mean? Curious .....