Thank you for the education .

I will try to find the SAE paper regarding GM's study on filtration efficiency and the reduction in wear they experienced by tightening up the filtration. It wasn't in the 5 micron range, and their results would blow your mind.

Many of the bypass filtration companies throw around micron ratings and "test results". Bypass filtration works when implemented properly, with proven products. Many of the well known bypass products filter down around 2-3 microns absolute. Sub micronic material is of little detriment, so the manufacturers focus on the range of particle that show the most harm in whatever machinery they are protecting.

So I tried to access the SAE file but it's locked(have to pay to view it). At any rate this article includes part of that study. Keep in mind that GM tested different micron sizes and this is only part of the complete study performed.

http://www.machinerylubrication.com/...ass-filtration

I run the K&N HP6002. It's the longer version of the HP3002. Figure more filter area and flow. Filters down to 10 microns and has the highest burst pressures. chrisf695, These advertise as not having a bypass valve.
http://www.summitracing.com/parts/knn-hp-6002/overview/

Just remember bigger isn't always better ;). In all seriousness though, it's true. If the application doesn't warrant the bigger filter, it isn't improving anything. Yes that filter does not have a built in bypass valve.

***For anyone with the GM oil bypass valves build into your block, an oil filter without a built in bypass is the proper one to purchase. IF your block is plugged, select a filter WITH a bypass valve built in.

im a big believer in bypass filters. for dirty ass diesels going a long time between changes.. as much as we change our oil and as efficient as our engine run (blow by) i dont see a need for it,
just what ive learned at class for work (cummins).

[QUOTE=

***For anyone with the GM oil bypass valves build into your block, an oil filter without a built in bypass is the proper one to purchase. IF your block is plugged, select a filter WITH a bypass valve built in.[/QUOTE]

I run the filter with no bypass valve and my block is plugged. I change my oil and filter often. I watch my oil pressure close always! I feel it is less risk than the chance of unfiltered oil going straight to the bearings.

A good buddy of mine has a toilet paper filter in his truck (400k miles) oil always looks clean.You can wipe the dipstick on a white paper towel anytime and its always clean oil.When he changes the oil its cleaner coming out than going in. :D
http://www.kc-synthetic-oil.com/toil...il-filter.html.

Glad it's working for you, however some folks aren't that great about filter changes, and IMO going plugged, selecting a filter with a built in bypass is the way to go. I think many times we are driven by what makes us feel good, not actual data. Most don't understand that bypass valves operate on differential pressure, not actual pressure. Take the 30lb oil bypass valves for example, something would need to be terribly wrong to take one of these off the seat. With no bypass valve at all, what if the filter fails internally? It happens. Not a risk Id like to take.

The two collapsed filters I dealt with both had bypasses. Didn't help. They both came in because of having almost no oil pressure when driving.

Just my very small experience in this regard.

Just ordered the K&N. $12 on Amazon. Also now that I've ditched the manifolds there's room for the tall filter.