bill99gxe

iTrader: (1)

Nissan VQ30DE OEM filters use a 14psi bypass valve rating on an engine that has a 10psi idle speed oil pressure. Although the VQ35DE increased to 14psi idle speed pressure, they begain specifying the SR20DE filter, which also uses a 14psi rating.

This information for the SR20DE OEM filter for the bypass valve psi spec does not come directly from Nissan, but rather the specified cross references from Baldwin and Purolator for the late-mode Sentra SR20DE engines, which continue to recommend a 14psi bypass valve oil filter. Therefore, a VQ30DE spec oil filter will work on the VQ35DE and is probably preferred over the VQ35DE filter since its size has been reduced.

One good true oversized filter, fits, and has a bypass valve rating near that range (17 to 22 psi) that is acceptable is the STP S6941. Unfortunately, it is $7.00.

For more info, go here:

http://forums.maxima.org/showthread....hreadid=150186

KL99SEA

iTrader: (1)

Just bought a Fram TG7317 to do the 1st change, thats what the Fram book said for a 2K2 3.5.....Is this ok for my 2K3?

deadrx7conv

Whats your definition of "bypass pressure"?

Isn't it a pressure differential between the input/output pressure of the filter and nothing to do with actually oil pressure?

I don't know about you, but to have ouput pressure 17-22psi lower than input pressure at the filter is a problem. I think that every oil filter/auto manufacturer would understand the importance of total oil pressure and adjust the filters accordingly. Plus, the filter never totally bypasses filtration. It bleeds the oil volume and never allows a decrease in 'total oil pressure loss through' the oil filter by its set amount(usually around 10+psi). The only way to completely have oil filter bypass is when the filter is totally clogged, and this is almost impossible with regular changes with todays engines. If the filter does clog, you will need a new motor anyway.

Another note, I have rarely seen vehicles with two oil pressure senders(before and after oil filter). This is one reason why 'oil bypass pressure' shouldn't be brought up in comparison.

I don't know about you, but to me, 60psi of partially filtered oil is a helluva alot better than having 40psi of fully filtered oil at 7000rpm at the crank/cam bearing.

The problems with mixing oil filters is that different engines have different oil volumes. Each filter is design to filter a certain volume of oil and if you exceed that volume, you will have excessive pressure differential bleeding the oil. Big sized filters and big filter surface area are two different things and everyone should use the recommended filter.

nick778

From what I have read on the subject, it is indeed pressure differential across the filter media and not pure bypass psi opening that is meaningful. Otherwise, almost every car would be in bypass at slightly above idle speed.
For the 2k2-2k3, the Nissan OEM filter that was designed orginally for the Sentra(replacments from Nissan don't even mention the 2k2/2k3 Max yet), I don't see why replacements as the Purolator L14610(with a bypass psi of 14-18) or the Bosch 3323 with similar bypass psi but with the preferred baseplate mounted bypass valve cannot be used as a slightly oversized filter replacement to the ultrasmall nissan oem filter for the vq35. Their mounting diameter is exactly the same and you pick up about 3/4" of length(and a presumable increase in filter media area all other things being equal). The Purolator L24458, on the other hand, has an bypass psi of 8-10 and I'd be leary of using this on 2k2-2k3 Max.
Bill, do you have the size specs for the stp6941? Looks somewhat large to be relative to diameter and the mounting face on my 2k3.
One has to wonder why Nissan went to the smaller Nissan Sentra filter in the first place given that larger filters would fit, the engine displacement got bigger as did oil capacity(over the 95-99 max anyway which uses a larger filter). Any ideas?

bill99gxe

iTrader: (1)

My definition is a relative one and simply revolves around the oil pressure differential between the VQ30 and the VQ35 filters. I really don't know if Nissan gave a great deal of thought to oil filter selection based on Nick's statement regarding the use of a Sentra oil filter. My explanation revolves around simplifying the argument rather than complicating it, as well as my aggressiveness in cutting and pasting rather than outlining my findings with other properly contextual comments as well.

The likelihood of going into bypass with the VQ30 is much higher on a VQ35 than is good for the motor. That's the main reason behind not recommending a VQ30 oil filter.

Unless you are racing to 7k constantly and winding the VQ like a Honda, what the filtration does at redline isn't really an issue. If this were a free-er revving engine that needed to stay above 6k to maximize power (a la Honda style), I would concur more with your contentions.

Good points though.

bill99gxe

iTrader: (1)

Nick,

The 6941 is a top bypass valve design, which is my main gripe as well against the Purolators.

Size specs (approximate, taken from Baldwin cross reference):

3" x 4"

They are about 3/4" longer than OEM and a 1/8" or so wider, IIRC.

For Bosch's, the 3323 does work for VQs and the 3312 is being researched.


The Purolator 14610 is probably properly rated for the VQ35, as it looks like Purolator went more "universal" for that new filter to take over the design flawed 14620. I would avoid the 24458 as well.

Nissan went with the Sentra filer for cost cutting reasons, which drives most everything they do these days.

nick778

Thanks. Sad that for cost cutting reasons Nissan decided to save a few pennies on something like an oil filer for their crown jewel...the vq35, that is also used in the 350z, g35, the new altima and pathfinder.
I have noticed that in these applications, the 'Sentra' filter is also specified. Guess these folks may be having these same discussions...especially the 350z crowd.

bill99gxe

iTrader: (1)

Well, the cost cutting is speculation. Obviously, Nissan tinkered with the oil pressure on the VQ35 for a good reason, as I doubt they would do that for the heck of it.

But with different engines using the same filter (i.e. the Sentra's motor versus the VQ35, etc.), one has to wonder how viable the OEM bypass valve rating is and how much it acutally matters in the real world....

But on the other hand, why change the filter spec if it wasn't warranted, since the VQ30 filter is still around, unless Nissan is phasing that part number out of production.

deadrx7conv

I wasn't trying to complicate anything. I saw an incorrect statement concerning oil pressure and oil pressure differential. And, I gave you a definition in the form of a question so that you can do your own research. Sorry if I was too polite. Next time I will be blunt/harsh when I read BS.

Oil pressure is at every RPM. I used the 7000rpm just as an example to get people to think. From the looks of the oil pressure specs at the other rpms, I again would say that more oil pressure is better. To hell with high oil pressure differential. If the filter clogs, I want as much pressure as possible. If it never clogs, ditto. If Nissan increased the volume of oil flow, then the higher pressure differential was due to the increase in volume.

And again, screw bypass. You would have to measure oil volume flow at every rpm and before/after oil filter pressure ratings at each rpm to even consider using the oil pressure bypass during filter comparison. As long as the filter or oiling system is capable of bypass, then noone needs to worry about oil pressure differential. And, if it is so important, get a dual remote oil filter(parallel) and never worry about it since you just doubled the filter area.

bill99gxe

iTrader: (1)

Bump, to reflect more accurate info and that most VQ30DE filters should cross reference fine with VQ35DE engines based upon some more research I did this morning.

I trust Baldwin's and Purolators cross reference spec's, given their information is pretty accurate, especially Baldwin, when it comes to cross references and proper bypass valve psi pressure settings. Looks as though Nissan is trying to go to a "catch all" oil filter application for what I'm sure is cost and production reasons.

I would imagine the Nissan OEM VQ30DE filter is on its way out of production since the 2k2 and up VQ35DE now uses the SR20DE filter. The main thing I don't like about the "new" filter is it's a good bit smaller than the VQ30DE filter. Were it me, and I was insistent on using OEM Nissan filters, I would purchase the VQ30DE part number 15208-00001 instead of the new VQ35DE 15208-00006.

I'll begin more seriously putting together a complete VQ cross reference list of available oil filters, their pros and cons, etc.