In my ubiquitous oil filter research, bypass valve psi settings are getting in the way of me finding copious, decent, and cheap oversized cross reference applications for OEM oil filters, particularly for the VQs, so I did a little research and discovered the following:

VG30E Oil Pressure:

Idle: 9+ psi
3200 rpm: 53 to 65 psi

VE30DE Oil Pressure:

Idle: 9+ psi
3000 rpm: 60 to 74 psi

1995 to 1998 VQ30DE Oil Pressure:

Idle: 10+ psi
3000 rpm: 63 to 80 psi

1999 VQ30DE Oil Pressure:

2000 rpm: 56.6 psi


Oddly enough, on 99 Maximas, that rating is stated at 56.6psi at 2000rpm. This is stated in the Haynes manual.

The OEM Nissan filter for the VQ30DE has a bypass valve setting of 14psi.


What I'm looking for is the oil pressure for the VQ35DE since Nissan is utilizing a different filter with perhaps a different bypass valve pressure reading to better complement a different oil pressure and/or to accommodate the VTC implementation in the VQ35s like there were on the VE30DE which required a "special" VE only oil filter.

If anyone has a link or 2k2+ service manual which alludes to the VQ35 oil pressure I would appreciate it.

 

dunno if this helps

 

I know this isnt the 2002 but here is all of the 99.


Idle speed More than 69(.70,10.0)

2000rpm 390(3.98,56.6)

 

Thanks Matt,


That at least verifies the FSM versus the Haynes Manual.

 

Its cool that you brought this up bill, b/c I plan to measure my oil press before I replace the oil pressure regulator on my VE this comming week. I'm thinking that poor oil press has to do with failing VTC's and damaged lifters and any other decrease in engine performance.

The bypass valve data is interesting, is that data available for all filters? I'm currently using an AC/DElco Ultraguard gold (filters 10-12 micron size particles).

So I guess for the magority of us that likes to drive our engines hard, is where a lot of the engine wear comes from, poorly filtered engine oil. So a bypass system with micron filtration would be very beneficial to everyone (hard drivers and regular drivers), b/c then a little bit of bypass wouldnt harm the engine at all b/c the oil is always clean.

 

Whether the VE uses an internal bypass valve or not is a mystery. My 94 FSM does not make this clear in the least. Some engines do have internal bypass mechanisms, and I suspect it's the case with the VG. However, the "Lubrication Circuit" diagrams for the VG and VE are the same at the oil filter, so perhaps the VE does have an internal filter bypass in the engine as well.

I'm wondering whether Nissan integrated a bypass valve into their "new" VE only OEM oil filter so that oil starvation to the VTCs would not occur, thus limiting the issues with the VTC problems for customers who used OEM oil filters, and possibly explaining why the 94s have "fewer problems" with the VTCs needing rebuilds since the filter redesign would have benefitted the newest VE equipped Maximas.


BTW Eric,

You owe me another analysis.

AC Delco no longer makes those filters. The UltraGuards went on closeout are nowhere in my area.

 

thats from the 2k2 FSM

 

Then I guess you havent checked carparts.com . I recently bought 6, I wasnt going to go overboard and buy 12 b/c in the future the synthetic filters will be more available. BTW if you want a sealed case, they come in quantities of 6.

 

When did you purchase those? They are good filters, just no longer made.

 

Thanks Sprint.


VQ35DE Oil Pressure:

Idle: 14+ psi
2000 rpm: 43 psi

Anyone else find it interesting that the oil pressure at 2000 rpm for the VQ30DE is 56.6, while for the VQ35DE it is 43.

 

It's also interesting to note that there is a 30% to 40% increase in oil pressure at idle for the VQ35 compared to the VQ30........

 

I'm sure less oil pressure on the VQ35 helped a bit on the HP.

 

Nissan has a trick up every sleeve to milk the VQ for all she's worth.

 

What caused the change in oil pressure? Bigger oil pump? Better oil pressure regulator? Or tighter engine clearances? Smaller oil passages?

 

Bill - Regarding the bypass valve and your statement, let me explain what the bypass valve does:

The bypass valve is there so when the pressure difference between the inlet and outlet side of the filter becomes to high it will bypass oil around the element. This does not mean that it opens when the system pressure is greater then 14 psi.

You are filtering oil 100% of the time no matter what pressure your lubrication system is running at. 14PSI - 56.6 PSI doesn't matter.

When your filter element becomes clogged and the pressure difference across the element becomes to high, the bypass valve will open to releave the pressure. This will protect against a collaps of the element and complete contamination of the lubracattion system, and maintain correct system pressures in the oil channels.

If you've got a new filter, the pressure drop across it should be basically zero. As it starts to become clogged with dirt, the pressure drop across it will increase. Your oil pump may be pushing 56.6 PSI, but if your element is dirty you may drop 7 or 8 PSI so your engine will only see 48 - 49 PSI.

The bypass plays 2 rolls here. One is for protection against the element collapsing and complete contamination of your oil. The other is to make sure you constantly have enough oil pressure in the oil channels to assure proper lubrication, no matter what condition the oil filter is in.

There are many tests involved which determine filter ratings. Flow capacity will also effect pressure drops. If the flow rating is to low for a given filter, the pressure drop will be high across that filter causing it to go into bypass mode sooner then necessary. It's extremely important to size filters correctly. Don't be fooled by size. A 10 micron filter element will flow much less then a 25 micron element of the same size. You'll get better filtration with the 10 micron element, but it will become contaminated much quicker then the 25 micron element will. In some cases it may not last 3,000 miles without going into bypass mode, especially if your engine isn't clean to begin with.

It would be very interesting to see what the micron ratings of all these filters are. In servo hydraulic systems, the ratings are usually very tight. Filter elements down to 3 micron are used to keep them clean. I highly doubt that the automotive industry is comming anywhere close to that kind of filtration with engine oil. From what my company sells in spin on filters, my guess would be automotive filtration is somewhere in the range of 20 micron.

To further complement your spread sheet, we should start collecting filtration ratings from the filter manufactures. These ratings should include the filters beta ratings, micron ratings and flow capacity. It would make the data you've collected come together very nicely.

Tom

 

Tom,

Thanks for taking the time to explain it. I did some more research late last night, and my initial research in bypass pressure was on a false premise. Your comments are right on. Thanks for taking the time to state it in a clear and concise manner.

I modified my post(s) in the 5th gen forum, but failed to so here.


From my understanding, a new filter will have a pressure drop of around 0.5 psi due just to being on earth. Obviously, not a big deal there.

Most mainstream filters such as Purolator, SuperTech, and STP have 20 micron filter ratings while the Bosch has one of 15 (info is courtesy of KCDoug when he called the tech line the other day). Generally, OEM Nissans are 22 to 25 microns in filtration. However, in terms of efficiency, the Bosch has a slightly lower efficiency rating than the others.

Filter Single Pass Efficiency Multi - Pass
STP Same as Mobil 1
Super Tech 98% 99%
Bosch 98% 93%
Mobil 1 98% 95%

Those values come directly off the boxes. I believe member KCDoug alluded that the STP's efficiency numbers were on par with Mobil 1's, based on his coversation with Champion Labs' tech line.

It stands to reason that the more (i.e. smaller) you filter, the less efficient it will filter. However, this is splitting hairs and only probably matters if you go over 5k on a filter, which I no longer recommend in general.

 

Anytime Bill, keep up the great research work!

 

Yeah I just checked, they are not available for 4&5 gen's.

But they are still available for us 3rd geners

 

Interesting......do you have to buy in case quantities? Looking at carparts.com, they are $10.57 each? I hate to ask if that is per case or per filter. Heck, I would just go Mobil 1 at those prices.

 

Yeah the price is each. I miss spoke earlier, this filter will go down to 8-10 micron size particles, the mobile 1 filter will do 10-12 size particles. I think the price is reasonable for the performance it delivers over the competition. Also by me the price of mobile 1 filters is over $10

There was a graph from Amisol that I cannot locate, it illustrated how filtering below 10 microns substantually increases the life of the engine.

 

After shipping, it seems to me like the price difference would be negligible, but I guess that depends. Since they aren't made anymore, stock up while you can.

I am familiar with the graph you're speaking of. Do you happen to know the single and multi pass efficiency ratings of the Ultraguard Gold? It's probably no better than Mobil 1's 98/95 (that doesn't mean it's bad, just higher micron rated filters tend to have better multi-pass efficiency because they aren't trying to catch everything so small).

 

Why are all the makers going to ultra small oil filters? Toyota/nissan etc.. have them. Has anyone found concrete evidence that the smaller filter is not holding up well or just as well has "oversized" ones?

 

I dont know what you are talking about Jeff (clerificatin required). Do you mean the physical size of the filiter? or the quality of the filtration?

Ofcourse a physically larger filter is better, capable of filtering the smallest particles.


-Bill, I dont have the single pass efficiency with me, but I know its up there (I can check when I get home). Also, I generally dont pay shipping from carparts.com , infact every oder I've place was free shipping. All you have to do is search for 'coupon free shipping carparts.com'.

 

Physically smaller filters. I was using Toyota filters and they were ultra small. I don't know what the size of the filter has to do with the micron ratings. I would think it would be the media and filter design.

 

Depends on how much actual filtering media is used. From what I understand and have researched, Toyota uses a relatively high level of filtering media in their small physical filters.

The only filter I've seen lab proof of being fairly inferior from an OEM standpoint are the Canadian/US-spec OEM Honda filters. But considering AlliedSignal (i.e. Fram) is making those, that's not really a surprise. Nissan OEMs seem to hold up well. We don't know how Toyota OEM filters hold up from lab results because your VE is so screwed up internally anyway.

Nissan's OEMs haven't been that small until this latest iteration, used in the Sentra SR20s and now the 2k2+ VQ35s.

The main knock I have on the Nissan OEM VQ30 filter is the lack of a top bypass valve since I do extended drain intervals. The tinier the filter gets, the less that probably really matters.....

 

Here is an illustration of the oil pressure regulator that I'm replacing on my VE.
http://www.vtr.org/maintain/tr6-spinon.html

The kit that I purchased from nissan is $10 and includes two springs, a piston, spacers, and an end cap. I was amazed at how inexpensive it was.

So the FSM shows that the piston can wear down on the sides (from friction) something I'm going to measure and compare. Also the spring can wear over time, as it gets weaker it'll allow more oil pressure to be relieved.

One thing that the FSM does not go into detail is how many spacers to add. If I add too many then the oil press will be too high and vise versa.

 

Actaully the VE filter is much larger than the VQ

Also Fram $ucks http://www.yft.org/tex_vfr/tech/filters.htm

 

Yeah, the VE OEM filter is special, I'm referring to Jeff's Toyota OEM cross-reference filter he has used in the past for his VE. Too bad he has coolant loss issues.


Interesting coincidence, as that link was where I did my additional research on bypass pressure last night.....looks like I'm not the only one who can use Google search.

I originally found that link looking for VQ oil filters, and little did I know that Honda VFRs, CBRs, etc. could use the same filter.

 

Good question Jeff....is there something the import engine makers know or are doing that domestics don't? My damn crappy 95 Escort has a larger STOCK sized filter (SDF-36) than the oversized 6941 I'm using on my VQ. What in the world is used to determine the size of filters at the OE level? Is it nothing more than inlet/outlet size and pressure ratings? Do filter media (types, depths, etc.) and overall can size (ie. largest possible fit) not enter the equation? Just wondering.....

 

The solution is to use remote oil filtration. Then you can choose whatever filter you want.

 

Bill here is the info for the AC delco ultraguard gold filter. The package didnt have that much info, it was in like 4 languages . but it did state the 8-10 micron single pass efficency (but did not give a % figure). the info is on the www.acdelco.com site, single pass is 98%, You guys gotta check out all the info they have, I was impressed.

http://www.acdelco.com/html/pi_filt_oil_gold_flow.htm
http://www.acdelco.com/html/pi_filt_oil_gold_single.htm
http://www.acdelco.com/html/pi_filt_...ld_feature.htm
http://www.acdelco.com/html/pi_filt_oil_gold_comp.htm
http://www.acdelco.com/html/pi_filt_oil_gold_main.htm


I find the flow data very interesting, and I like the fact that this filter kicks the butt out of mobile 1 (now renamed mobile 2)

 

Very interesting data Eric. Does anyone know how this compares to the STP and Amsoil filters?

 

Impressed? I got some beachfront property in Antartica to sell, and I am selling house lots on the planet Venus. If anyone is interested, send me cash.

And you trust manufacturer data? Ever hear any manufacturer claim that they were 2nd/3rd best? So, what is a SUS2000 oil simulator?
How about 'hot' oil pressure differential bypass since oil is only cold for a few minutes and you shouldn't beat on cold engines?
Every manufacturer will locate a test that makes their filters look the best. Yeah, ACDelco is unbiased.

And for single pass effieciency(spe/spfe), at what oil temp? at what oil volume? at what oil pressure? Or is this just another spec that can be manipulated by the manufacturer. And read to understand a little better:
http://www.shotimes.com/SHO3oilfilter.html
Notice that filters don't dump oil during oil filter bypass. It bleeds off pressure slowly, and amount bled off is limited to the bypass diameter.

And pureone claims that they are the best:
http://www.pureoil.com/TEMP_old_site/faq.htm

And amsoil claims that they are the best:
http://amsoil.com/products/sdf.html
Which company makes the amsoil filter for amsoil?

And synlube & mobil1 claim that they are the best:
http://www.synlube.com/prod06.htm
Who makes the synlube filter for synlube?
http://www.mobil1.com/products/filter.jsp
Actually, they are better than a conventional filters. Do they define conventional filter?

Holds more dirt than the leading national brand. If anyone wants to prove this, I'll help pour the dirt into your engine.
http://www.wixfilters.com/productinf...ilfilters.html

This might help with your oil filter comparisons:

Allied-Signal makes: Fram, Autolite, Quaker State, Pennzoil, and Bendix.
Champion Labs makes: ACDelco, AutoZone, Champ, Champion, Car & Driver, Deutsch, Lee, Lee Maxi, Mobil 1, OEM Motorcraft, OEM GM, STP, Valvoline, Many OEM brands and over 100 private label filters.
ArvinMeritor makes: Aftermarket Motorcraft, PowerFlo, ProLine, Purolator Pure One, Purolator Premium Plus, Quaker State, etc.
Dana Corporation makes: CarCraft, Napa, Wix, etc

There's some overlap due to certain private labels switching suppliers. You never know which company gets the lowest bid when "insert brand here" decides to order a warehouse full of filters for their stores/customers. This means that filters can change from time to time.

Fram filters don't suck. It has been and is being using by 10's of millions of people. Its cheap and passes all manufacturer requirements which is usually different between manufactures and why I don't care for cross referencing. Cross referencing using filter thread size is risky.

What I am trying to get at is that everyone SHOULD use the recommended filter for their vehicle(especially if under warranty). Don't give the auto manufacturer/dealer an excuse to deny repairs.
And, if you must play musical filters, buy a remote oil filter kit and have fun.

 

Great info and rebuttal, but doesn't this assume that the manufacturer recommends the BEST product for the respective vehicle? I find that very hard to believe. I find it much more likely that manufacturers find the best product in terms of cost effectiveness to the bottom line as long as it meets some minimum operative spec rather than the best filter available. I understand the warranty argument, but can they deny a claim if the filter you are using is rated with the same nominal specs? If they were concerned about what was best for vehicles rather than the bottom line and service calls, why not spec. synthetic fluids, filters, etc since they clearly outperform the majority of conventional options? Not trying to argue, just understand your rationale a bit more. Thanks for the info!

 

The inability for you to provide information (which I and others have seen and is found all over the internet) in a manner that is respectful of others contribution attempts marginalizes your own contributions and gives me the desire to delete rather than respond to your information and contentions.


There's a fine line between being a smartass and being smart. Trust me, I walk it everyday.

 

Understood!
I had too many smilies and deleted them all to post. I should've knocked the smilies out one at a time until the post was allowed.

You mean that Nissan doesn't want the BEST for my car Damn beancounters.
My rationale, I'm eccentric, so it is more like irrationale

We all agree that oil filters have built in bypasses that open between ~8-~22psi depending on brand etc. Right?
Then, why don't all these filters revert to full bypass and zero restriction(if possible) once the differential exceeds the spec?
http://www.acdelco.com/html/pi_filt_oil_gold_flow.htm