Originally Posted By: Jim Allen
Of course a magnet will help catch ferrous material in the oil and of course that's beneficial. Whether it's a cost effective modification (given the cost of the good magnets) is another matter.
The better magnets will catch most, if not virtually all, of the ferrous material running through the filter.. and safely hold it there. The question is whether that will have a noticeable payoff over the time you will own the car. If you are like me and keep cars for decades (we still have the '00 AccordV6 bought new) it might pay off. If you will trade the car in at 100K miles, probably not. Thing is, the Accord V6s are not notorious for shedding iron (find UOAs in the the appropriate section) so if you take care of the car normally , it will still go 200,000-plus miles without spending the extra hundred on a whiz-bang magnet. In an abstract, cost is no object, sense... heck yes, go magnetic. I'm just not sure the long term payback is there.
Alternatives include using the magnets from old computer hard drives... high quality magnets. Maybe not as good as the Fitlermag kinda stuff but an improvement. Ditto for a magnetic drain plug. BTW, my Accord does not have a magnet on the engine drain plug but does on the transmission.
IMO, worrying about a filter bypass event "flushing" the iron off the filter can and into the oil is pedantic. Could happen but the odds are way, way against it. The same bypass event could flush all the junk off the filter media, with or without the magnet... and the magnet is at least HOLDING the iron versus the junk on the filter media just laying there for the most part.
I think you've about covered it.
Magnets are not new in filtration. The benefit is questionable. If one uses magnets and finds a lot of metal in their oil, you've got more problems than having a nice shiny magnet on the outside of the can.
Some filters may show some metal in the can when you cut it open. You'll find it at the bottom of the filter. The "bottom" may be either the dome end, one side of the element can if mounted horizontally, or near the threads if mounted inverted.
The by-pass valve should be located away from the "bottom". So harder for metal particlas to flush past. Obviously with a horizontal mount either engine end or dome end offer similar protection. Chances of larger metal pieces getting past the by-pass is still remote.
As the element itself filters particles the human eye can't see, why try to collect them on a magnet? Unless you know your element is getting plugged and the by-pass opening more often, then magnets might help. Chances are people in this forum change their oil and filter in a proper manner and won't necessarily be candidates for oil filter elements nearing the end of it's usefull life.
Magnets won't prolong the engine until it's next rebuild.
