a while back i found a thread here, on bobistheoilguy, that showed tests he did with various oil filters. the ones that restricted oil flow were at top, bar colored white, mainstream filters, were colored red, their were some bars for blue and green. it was a test he did, with and without a filter holder, at 10 and 20 psi for 10 to 20 minutes. i already looked thorugh the whol post! can anybody help me find it here?