Well I guess Rossjo and I can agree to disagree on the higher micron filtration. The Fleetguard filters that you are talking about look like an excellent set up with the 2 stage micron capability however as stated, these are for oil filtration on heavy duty diesel applications with extended service intervals. What I'm talking about is oil filtration on a typical gas engine in the average pleasure boat.
As Paul (prowlersfifh) stated,
prowlersfish wrote: I will have disagree with the use of the high micron racing filter . Your just not filtering the oil like you should . I don"t thing this would be a issue on a low hour and dust free environment like a pleasure boat . How often do you see a marine engine wear out ? most issues are from time and lack out use .
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I don"t thing this would be a issue on a low hour and dust free environment like a pleasure boat" is exactly why this type of filtration (27 micron) works for me. Although I use my boat often, it's still a pleasure boat and the oil gets changed long before it becomes a contaminated mess.
The simple truth of the matter is that at elevated RPMs, a typical oil filter on a gas engine cannot keep up to required flow (dirty or clean) which in turn causes oil to bypass the filter. This also stands true with the 27 micron filter however the volume of oil that bypasses the filter is reduced. Also, I don't want to confuse any one reading this who might not have a full understanding of the "bypass system". The bypass system ensures that oil is getting to your bearing surfaces filtered or not. And since this oil travels in a continuous circuit thru the engine then back to the pan, it always ends up going thru the filter somewhere along the way.
As Paul (prowlersfish) also stated, there's another way to achieve better filtration. The oil filter relocation kits, such as the one that I have installed, are also available in a dual filter configuration. This would double the filter volume capacity and possibly keep the bypass shut. Its a great add on if you have the space.
Any way, my choice in oil filters works well for me. The proof is in the engine.

I hope our discussion on filtration has helped enlighten others on the subject.
And don't get me started on oil.
