Originally Posted By: ZeeOSix
Originally Posted By: BOBISTHEOILGUY
If you have two filters, phyiscal size simular if not exact to meet the car specs, both have same bypass pressure ratings, only real difference is the media. One has less, the other more, which is going to allow flow easier? of course the lower media. Now, here's one thing I think is interesting.. These filters have bypass somewhere between 8-12lbs of pressure or there abouts. What is the pressure of an oil system? anywhere between 20-60lbs. So, one the oil pressure rises in an engine, the filter would be a restritor if it wasn't for the bypass, so, IMO, the filter hits the bypass pressure point and is in bypass from there on and that the only oil being filtered is what ever can pass through the media. Well, if the media is higher or has more restriction, then oil, like many things is going to take the least path of resistance. Point is, m1 filters is so effeicient that it take pressure to pass through the media, the fram doesn't as it will allow better flow because it doesnt' resist as much and that would mean more oil would go through the media vers the oil in a m1 filter.
So, in a nutshell, more flow through a low filter media or no or little flow through a high filter media, which would be better?
With a positive displacement oil pump, the flow at start-up going through the filter will be the same even if one filter is a bit more restrictive than another. Only exception to this fact is if the oil was so thick that it would cause the oil pump pressure relieve valve to regulate the max output pressure of the pump. That just doesn't occur unless you're cold starting at -20 deg F with 20W-50.
Also, the oil pressure of the system has nothing to do with if or when the filter's bypass valve will open up, as the delta-p across the filter is a function of oil viscosity and flow rate.
Yes, I know this thread is from 2002.
My mind is blown a second time.
