Wix vs. PureOne - Flow Restriction

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I'm trying to decide between the Wix (Napa Gold) and the Purolator PureOne for my 2004 Nissan Altima 3.5L V6. I'm told that this engine needs good oil flow and pressure for the variable cam timing mechanism and the cam-chain tensioners.

I've heard that the PureOne filter efficiency is very high, and as such, may mean that it is also somewhat restrictive to oil flow.

I was looking at the following by-pass relief valve specs for the two oil filters for my car's application:

WIX 51356 (same as NAPA Gold 1356) spec says: 8-11 psi.

Purolator PL14610 spec says: 14-18 psi.
(The regular Purolator L14610 has the same spec, even though the regular L14610 doesn't have the higher filter efficiency.)

Is this an indication that the Purolator is probably more restrictive to flow due to higher filtration? It looks like they set the by-pass relief pressure higher so there can be a higher pressure delta across the element.

Has anyone seen any actual flow vs. pressure drop data for either one of these oil filters?

I want to go with the PureOne, but don't want to sacrifice oil flow if it's too restrictive.
 
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Originally Posted By: Spartuss
Use either one. Both are excellent filters. Your Altima won't notice the difference.


I'm sure that's true ... but if the PureOne filters better without sacrificing flow I'd rater go with it; plus I think it's less cost.
 
According to a recent flow vs pressure differential graph I saw here, the Pure One actually had better flow than just about everything else.
 
Originally Posted By: chevrofreak
According to a recent flow vs pressure differential graph I saw here, the Pure One actually had better flow than just about everything else.


I'd be very intersted in seeing that data. Could you be so kind as to dig that up and link it, or tell me where to look for it? Thanks!
 
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Quote:
Has anyone seen any actual flow vs. pressure drop data for either one of these oil filters?


This data is only valid in a comparative manner. It has little meaning when in actual usage. Most data is either a flow at a given pressure ..or a pressure differential at a given flow rate. Both state a viscosity and/or temp of the fluid in use during the test.

The flow at pressure reading are into a zero pressure drain. This has little meaning when the engine is producing massive back pressure due to the incredible comparative restriction of the filter. It's like worrying about how big your front door is ..when the hallways inside are 1/25th in area.

When this can make a difference is when your pump is in relief. If the visc is too high or temp too cold (same thing), the pump may not be able to physically push the oil (or accelerate it quickly enough) to prevent the relief threshold from being breached. At that point, the filter's bypass valve limits total resistance that the filter can present to the supply.

This is "generically speaking".
 
Originally Posted By: Gary Allan
The flow at pressure reading are into a zero pressure drain. This has little meaning when the engine is producing massive back pressure due to the incredible comparative restriction of the filter.


So you're saying that the flow restriction due to the engine itself (flow passages, etc) is much higher than what an oil filter can produce in terms of flow restriction? - unless of course the filter was highly clogged. I guess that makes some sense.

If that were true, then the oil pressure you see on the input side of an engine's oiling system wouldn't really change much (or at all) if the oil filter was free flowing.

I’m assuming most oil pressure sensors in engines are on the down side of the oil filter, so if the filter was restrictive, the oil pressure reading would drop some due to the flow restriction.
 
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Originally Posted By: SuperBusa
Originally Posted By: chevrofreak
According to a recent flow vs pressure differential graph I saw here, the Pure One actually had better flow than just about everything else.


I'd be very intersted in seeing that data. Could you be so kind as to dig that up and link it, or tell me where to look for it? Thanks!


pi_filt_oil_gold_coldoil_thumb.jpg
 
Originally Posted By: chevrofreak

pi_filt_oil_gold_coldoil_thumb.jpg



Hey, I've seen that graph before. I think it was produced by AC Delco to show how much the Utragaurd flowed. I use to use them on my Z06 Vette. Thanks for the chart.
cheers3.gif


Only thing is, the pressure delta across the filter will cause the by-pass to open way before it gets above the 20 psid range, as most by-pass valves are set between about 8 and 18 psi (ref my 1st post in this thread).
 
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You may get great flow, but how much cleaning is going on?

I noticed the M1 filter is second lowest for flow, but those high-density media filters clean very well.

Which is more important? Easy flow, or good cleaning?

Obviously somewhere in the middle is best.
 
The Purolator Pure One is one of the most efficient filters you can buy, so if that graph is correct I see little reason to use anything else.
 
Well, if efficiency were the ONLY criteria to judge upon, I'd have to give the edge to Amsoil's EaO filter line. They typically have the best filtration performance for any filter that you could typically find spec'd for an engine. Not that PureOne, or Mobil 1 filters, aren't good stuff; they certainly are.

I don't know that a Wix to PureOne filter comparison is exactly fair; they are targeted at different market levels.

I use NapaGold (Wix) almost exclusively, because I get them from our sponsor, Fleetfilter, for such a darn good price that you can't ignore the performance/dollar ratio. But my OCIs are reasonable enough to warrant this consideration (less thank 10k miles). If very long OCIs were my target, than Eao's would rule. The PureOne and Mobil 1 fitlers are a nice compromise in between.

As Gary often points out, it's all in consideration of the filtration triangle.
 
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The Amsoil filters don't have and edge unless you're doing an extended drain. For short intervals the Mobil 1 filters beat them for filtering ability, and the Pure One's are said to beat the Mobil 1's.
 
Originally Posted By: Hethaerto
I noticed the M1 filter is second lowest for flow


I`ve read this about M1 filters on several forums.
 
Originally Posted By: chevrofreak
The Purolator Pure One is one of the most efficient filters you can buy, so if that graph is correct I see little reason to use anything else.


I'm with you, especially if you do reasonable OCI's.
 
Quote:
So you're saying that the flow restriction due to the engine itself (flow passages, etc) is much higher than what an oil filter can produce in terms of flow restriction? - unless of course the filter was highly clogged. I guess that makes some sense.


Side note: I've expressed this a few times ..make that many times ..and not too many people grasp the concept here. I obviously cannot express it in sensible terms. All conceptual views are integrated from observational data of real world testing with remote filters with individual gauges above and below the filter ..and/or a differential gauge. While I may not be able to articulate the physical events properly, they are what they are. If you can manage to read into it a bit ..massage it for your particular frame of reference, you may be able to have the same light bulb go off. You may even be able to expand and augment the interpretation/expression into more sensible terms.

All "truths" are generic. There will always be exceptions for those who operate in/on fringe environments or with some exotic/high tech engines. [/end disclaimer/qualifier]

The engine is by far the most restrictive element that the oil flow sees. It's what develops your pressure ..or back pressure. The oil filter is a slight intermediate choke to flow. As long as your pump is not in relief, then it is no more than a "rapids" ..actually, it's probably a "slow down" ..but the same concept applies. SAME FLOW, different velocity. What else can possibly occur with a positive displacement pump (assuming 100% sensible efficiency for discussion's sake) where 100% of the sensible flow goes to the engine?? The filter, and all intermediate restrictions (galleries ..passages ..bearings ..cams ..lifters) all collectively produce pressure ELEVATIONS back to the pump. It's what happens when oil molecules slam up against immovable objects and start playing bumper cars with each other soon after start up.

If the oil pump doesn't reach the relief point threshold ..then the filter is but one minor velocity change in an otherwise irresistible fluid flow. IT'S GOT NOWHERE ELSE TO GO. The filter must fall into a subordinate resistance of the total resistance of the fluid circuit.

Most view "flow" like we do faucets and electrical outlets. A supplied pressure with variable flow based on resistance. What we have in a non-pump relief scenario is:

How much oil is passing through a 2" pipe @ 5gpm?
How much oil is passing through a .5" pipe @ 5gpm?

A: 5gpm. The difference is just the velocity and the "back pressure" developed.

Now when we open the relief valve, the physics change. Now you are at an attenuated pressure over a given resistance. The filter is the division that sees this differential of developed pressure. It sees the supplied pressure on the pump side, and the developed "back pressure" from the engine based on the reduced flow going to it. The differential pressure is the difference between the sum of the total flow/output and the net flow to the engine.

The bypass valve limits the max resistance that the filter can present to the supply in the relief event.

Two important distinctions:

The bypass valve is there to prevent oil starvation to the engine during pump relief events.

The bypass valve setting is there to limit stress on the media (some exceptions apply).

Now lets take on the difference between "free flowing" and "restrictive" filters.

XYZ filter is "tight". It has a 10psi bypass valve setting.

ABC filter is loose. It also has a 10 psi bypass valve setting.

In pump relief, what is either filter's maximum resistance presented to flow?

Suppose XYZ hits 10 PSID
Suppose ABC only hits 7 PSID.

How much difference does "free flowing" vs. "tight" mean??



When does a bypass open?

A bypass opens (we're talking generically here) when you're in transition. Perhaps when you're in transition from dead still cold start, with empty galleries ..and a high volume void to fill before you develop (our infamous) "back pressure".

It can also occur when you're flat shifting @ 7000 rpm and the oil cannot physically stop on a dime. The relief is there to "bleed off" the transitional excess output. Between the relief and the bypass valve you have slack in an otherwise solid fluid train.

The bypass may also open when you start a cold engine with heavy oil. That static column of oil just doesn't want to move from ZERO to whatever instantaneously. So the pump spins its tires applying max pressure but producing little flow. This produces the maximum pressure on the pump side of the filter, but the least flow to the engine ..and limited "back pressure". As the train gets moving, the flow proportions more and more to the engine ..and the differential read across the filter ..evaporates.

Now this hasn't dealt with filter loading. Filter loading will elongate and exacerbate these transitions. Viscosity becomes a more reactive component in the equation(s). So, while you may not reach the bypass threshold of the filter after any relief event is over, you may see elevated PSID due to viscosity. But it is still a pressure elevation toward the supply and NOT a reduction in flow.

Did anyone hang in there this far??
 
Now is the point where I field objections.

I love fluid dynamics too. I really wish I had studied it.
 
I took two semesters of it in school, and a laminar fluid shear class. That, and two semesters of thermodynamics will drive a man to drinkin' ...
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