Is this a true statement about oil filters?

[Grease is the word]

"...the filter only sees about 10% of what the oil pump is putting out. the rest goes directly into the oil gallies via the oil filter bypass valve."

I read the above quote by a marine/boat mechanic on another board. My impression was that once the oil is thin enough due to engine heat virtually all oil would flow through the filter.

 

[T-Keith]

At startup, some filters would be in bypass. Remember Bob's test. Thr Fram was in bypass with room temperature oil, but none of the others were.

-T

 

[TC]

I suspect that 10% claim is true, but only under the usual bypass conditions -- initial starts, cold oil, improper weight (way too thick) oil, high RPMs, throttle jabs, and clogged filters. If we experienced this 10% filtration under normal driving, this would certainly be an indictment against the efficiency of oil filters, something I strongly doubt, especially since substantially increasing the media area would likely solve the problem, a fairly simple fix.

 

[RedWolf4000]

I have a 1987 Toyota 4x4. It has 419,000 miles on it, i have used nothing but AC Delco filters. I have also stayed away from fram. Ac Delco has proven to be a great filter. I now have a 03 cavalier, and it takes a catridge filter, so i can actually see the quality of the product and the ammount of filter media. The AC delco's media is wrapped completely different from the cheaper brands, there is also much more media, and although the fram didnt have cardboard ends or anything, because its a catridge type, the ammount of dried glue running down over the media was enough for me to put that right back where i found it. AcDelco's efficenty rating is very good also, for a non-high end synthetic media filter.