So I'm well aware of the superiority in terms of filtration rate of the fram XG series, however how much does it impede flow rate? I obviously don't want to be running a portion of my flow through the bypass at higher RPM's. I want to utilize the better filtration but am wary of the flow tradeoff. Vehicle is a 19' Ram 5.7 running Shell Rotella Gas truck for now
Flow vs filtration rate
- Thread starter LevelZero
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No more than other filters
The positive displacement oil pump overcomes any slight flow restriction in oil filters. The oiling system in an engine is not a pressure source system like the water system in your house ... it's a positive displacement volume supply system.
Fram isn't going to design the bypass valve to open unless necessary, so don't worry about it bypassing unless it's loaded up and you rev the engine really high with stone cold thick oil in the winter time. There is no "flow trade off".
"LevelZero" is the latest?
so it seems
Truck has roughly 14k miles on it, been running Wix filter with shell Rotella gas truck oil. Will replace the air filter at 20k. Ive run the fram XG before on V6 Toyota and Nissan motors, but with the higher flow demand of the V8, idk maybe its paranoia, but something in the back of my head says frams filter media is more restrictive and will pull flow from the bypass valve when running hard (which is a decent percentage of my driving)
Hmm?
I'm not sure I follow the thought process that a V8 has a higher flow demand or that a FU is more restrictive than any other brand. Is there specific data on either point you can provide? I wouldn't expect any filter that has been used at a appropriate interval to go into bypass except as Zee0Six described.
No one really follows that thought process.
The more fine the filtration, the higher the flow impedance. Given our vehicles usually have full-flow filters, everything the oil pump pumps has to go through the filter, so it's either going to go through the media or around it in bypass mode. These filters can only do so much. I tend to think the fancy expensive 'mega micron' rating filters are overrated.
When they say the capacity is a certain amount, like in grams, or miles, they are saying that's the cut off limit for restriction before the oil bypasses the element. So you have to trust the restriction is not enough when new to cause the bypass to open under almost all conditions. That would be no good. . If not, move on to another brand. How can you trust one over another? I can see grams, but can't see miles, which is a range based on some average particle load rate they are assuming. Grams must be some kind of range too because thick oil and low temp combined with say half the stated capacity could possibly cause the bypass to open. Is that confusing enough?
That broad statement about flow and restrictions is not universally true, it depends on the media.
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Don't get too concerned about these "alleged" flow restrictions- they are more myth and misunderstanding than an actual reality to be addressed.
This is still one of the largest misconceptions on this chat board. With modern day full synthetic filtering media, a filter can have both high efficiency and low flow restriction (ie, meaning low delta-p across the media at high flow rates).
Jay (Motorking) provided delta-p data for the Ultra, and it flowed very well (slightly better than the graph for the PureOne below). There was also a long standing misconception that PureOne filters were also "flow restrictive" because they were so efficient. Purolator provided some flow vs delta-p data of the PureOne and it showed a very low delta-p even at 10 GPM of hot 5W-30 viscosity oil flow. Absolutely nothing to worry about.
The misconception of "high efficiency oil filters are too flow restrictive" will never end, even though oil pushed through them is by a positive displacement oil pump so it doesn't really matter if a filter is a few more PSI delta-p restrictive than another.
Impedance was poor wording on my part and I'm not disputing any of what you guys above are saying or Motorking's data, but those pressure/GPM numbers are based on a specific test sample. There's probably 100 or more different sized filters and so many other variables at play in terms of oil, oil condition and temperatures, it's difficult to say one style media benefits an engine better than another in a full flow filter application. I thought that's what this thread was about, but could have missed the mark.
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