Change oil filter every other oil change??

[flatlandtacoma]

Originally Posted By: electrolover
like i said spaces filled that would be void = less flow. i dont know how much because i have not measured but i do know it drops flow. THATS COMMON SENSE!!
You know that it drops flow? Do you understand how a positive displacement pump works?

 

[Gary Allan]

do you change your skivvies every other day????


when you get out of the shower do you put on dirty cloths?



These are the false impressions that crack me up.


Let's look at it another way:


Do any of you feel like your itching half way through the day? Are you totally ripe and pretty much untouchable past noon? Does your wife call you Mr. Stinky when you get home @ 5pm? Do you avoid close quarters after lunch with coworkers?

No?

Then if you're not about to get a hazmat team involved when you DO take your shower, if you're perfectly comfortable all day long ..you're clothes aren't standing when you take them off...

..just what would be wrong with them IF you showered TWICE A DAY??

Would they magically get skid marks to appear? Would you emit MORE disgusting secretions from your body having showered mid day? I hope not, but you may not be from this planet ..so..

Then why would not changing your filter when it is in perfectly serviceable condition such a "crime"?

You're just looking at it from the wrong end of it.

 

[flatlandtacoma]

Gary, post the links to your filter dp testing. Maybe they will listen to you.

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
Originally Posted By: electrolover
really? a new element will flow the same as a used element? thats not very swooft. even if its not "loaded" flow decreases as the filter catches particles because those particles however small take up space that would otherwise be void. its common sence...
Yeah, really. The dp across a filter, even a moderately dirty one, is very small. And the oil pump is positive displacement. Both filters flow the same.


Both filters will flow the same due to the positive displacement nature of the oil pump ... but only until the oil pump hit's relief pressure setting. Once the oil pump goes into pressure relief (ie, it can't put out any more pressure), then the more restrictive filter will flow less.

The more restrictive filter will cause the oil pump to work harder to push that same oil volume through it ... which in turn causes the oil pump to hit its relief pressure setting sooner than the less restrictive filter would.

 

[flatlandtacoma]

Originally Posted By: ZeeOSix
Originally Posted By: flatlandtacoma
Originally Posted By: electrolover
really? a new element will flow the same as a used element? thats not very swooft. even if its not "loaded" flow decreases as the filter catches particles because those particles however small take up space that would otherwise be void. its common sence...
Yeah, really. The dp across a filter, even a moderately dirty one, is very small. And the oil pump is positive displacement. Both filters flow the same.


Both filters will flow the same due to the positive displacement nature of the oil pump ... but only until the oil pump hit's relief pressure setting. Once the oil pump goes into pressure relief (ie, it can't put out any more pressure), then the more restrictive filter will flow less.

The more restrictive filter will cause the oil pump to work harder to push that same oil volume through it ... which in turn causes the oil pump to hit its relief pressure setting sooner than the less restrictive filter would.

All true. But the dp across the filter (even a moderately dirty one) is tiny. So none of this comes into play in the real world.

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
Originally Posted By: ZeeOSix
Originally Posted By: flatlandtacoma
Originally Posted By: electrolover
really? a new element will flow the same as a used element? thats not very swooft. even if its not "loaded" flow decreases as the filter catches particles because those particles however small take up space that would otherwise be void. its common sence...
Yeah, really. The dp across a filter, even a moderately dirty one, is very small. And the oil pump is positive displacement. Both filters flow the same.


Both filters will flow the same due to the positive displacement nature of the oil pump ... but only until the oil pump hit's relief pressure setting. Once the oil pump goes into pressure relief (ie, it can't put out any more pressure), then the more restrictive filter will flow less.

The more restrictive filter will cause the oil pump to work harder to push that same oil volume through it ... which in turn causes the oil pump to hit its relief pressure setting sooner than the less restrictive filter would.

All true. But the dp across the filter (even a moderately dirty one) is tiny. So none of this comes into play in the real world.


I wouldn't say it's "tiny" ... there's a reason for the filter's bypass valve, and some of the bypass settings are in the 14~18 psi range. That's quite a bit of delta P.

A filter that is more restrictive when brand new will go into bypass sooner with the same debris loading then a filter that is less restrictive to start with ... all other things being equal of course.

 

[flatlandtacoma]

Originally Posted By: ZeeOSix
I wouldn't say it's "tiny" ... there's a reason for the filter's bypass valve, and some of the bypass settings are in the 14~18 psi range. That's quite a bit of delta P.

A filter that is more restrictive when brand new will go into bypass sooner with the same debris loading then a filter that is less restrictive to start with ... all other things being equal of course.
You wouldn't say it's tiny? How large do you think it is?

Yes there is a reason for the bypass valve, but you are not going to open it except with cold thick oil when it has all drained down to the pan. The bypass valve setting is never going to be approached due to filter loading in normal service.

 

[Gary Allan]

Originally Posted By: flatlandtacoma
Gary, post the links to your filter dp testing. Maybe they will listen to you.



No way, man.

That's real world testing. Let's speculate in fairytale land of the imagination. It's much more colorful ..if "unreal"

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
Originally Posted By: ZeeOSix
I wouldn't say it's "tiny" ... there's a reason for the filter's bypass valve, and some of the bypass settings are in the 14~18 psi range. That's quite a bit of delta P.

A filter that is more restrictive when brand new will go into bypass sooner with the same debris loading then a filter that is less restrictive to start with ... all other things being equal of course.
You wouldn't say it's tiny? How large do you think it is?

Yes there is a reason for the bypass valve, but you are not going to open it except with cold thick oil when it has all drained down to the pan. The bypass valve setting is never going to be approached due to filter loading in normal service.


Sometimes service isn't "normal". I'm sure there have been instances where a filter was loaded up and flow restricted enough when the pump is at full tilt to cause a bypass event. And such loading just makes it even easier to open the bypass valve when the oil is cold or the volume high. A loaded up filter eats away the headroom between normal operating psid and the bypass psid. That's something to keep in mind.

Yeah, under "normal" circumstances you probably won't see much psid ... but there are many cases where the psid can be sufficient enough to cause the bypass valve to open. All it takes is the right factor or combination of factors (ie, loading, thick oil, high pump volume, etc) to cause high psid.

Like I said, a filter is designed to take the delta P across the media equal to the bypass setting. Some of these bypass settings are 12~18 and more PSI. So apparently the designer of such filters expect the possibility of some pretty high psid events during the filter's use.

 

[flatlandtacoma]

Have you read any of Gary Allan's filter tests? Might be eye-opening for you. The delta-p on even very used filters was almost too small to measure.

If you had reason to believe a filter may be loaded up after 1 OCI, then change it without question. Like I say, I have cut them open and from my vehicles there is nothing there. So I would have no problem following the engine manufacturer's recommendation and leaving it on for 2 OCIs.

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
If you had reason to believe a filter may be loaded up after 1 OCI, then change it without question. Like I say, I have cut them open and from my vehicles there is nothing there. So I would have no problem following the engine manufacturer's recommendation and leaving it on for 2 OCIs.


You (and anyone else in this free country) can do whatever you want ... leave them on for 5 or 10 oil changes if they look clean every time.

I always change the filter with the oil ... what's $5 for peace of mind. Besides, on a GM vehicle with the filter bypass built into the block, and set to 8 psi there is not as much headroom for filter loading. LS6 has high oil volume, and even with a brand new filter with 200 deg F oil there's around 5 psid at max pump flow ... that only gives a measly 3 psi of headroom for filter loading over the OCI ... not worth the risk for me to leave it on twice or more.

People can do whatever they want ... whatever makes 'em happy. I really don't care.

 

[flatlandtacoma]

Originally Posted By: ZeeOSix
Originally Posted By: flatlandtacoma
If you had reason to believe a filter may be loaded up after 1 OCI, then change it without question. Like I say, I have cut them open and from my vehicles there is nothing there. So I would have no problem following the engine manufacturer's recommendation and leaving it on for 2 OCIs.


You (and anyone else in this free country) can do whatever you want ... leave them on for 5 or 10 oil changes if they look clean every time.

I always change the filter with the oil ... what's $5 for peace of mind. Besides, on a GM vehicle with the filter bypass built into the block, and set to 8 psi there is not as much headroom for filter loading. LS6 has high oil volume, and even with a brand new filter with 200 deg F oil there's around 5 psid at max pump flow ... that only gives a measly 3 psi of headroom for filter loading over the OCI ... not worth the risk for me to leave it on twice or more.

People can do whatever they want ... whatever makes 'em happy. I really don't care.

I don't care what you do either. But if you are measuring 5 psid across your filter steady state you are doing something wrong or your bearings are shot. And if you don't like a manufacturer's recommendation fine, but don't make it sound like I recommended using a filter for more than 2 oil changes.

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
Originally Posted By: ZeeOSix
Originally Posted By: flatlandtacoma
If you had reason to believe a filter may be loaded up after 1 OCI, then change it without question. Like I say, I have cut them open and from my vehicles there is nothing there. So I would have no problem following the engine manufacturer's recommendation and leaving it on for 2 OCIs.


You (and anyone else in this free country) can do whatever you want ... leave them on for 5 or 10 oil changes if they look clean every time.

I always change the filter with the oil ... what's $5 for peace of mind. Besides, on a GM vehicle with the filter bypass built into the block, and set to 8 psi there is not as much headroom for filter loading. LS6 has high oil volume, and even with a brand new filter with 200 deg F oil there's around 5 psid at max pump flow ... that only gives a measly 3 psi of headroom for filter loading over the OCI ... not worth the risk for me to leave it on twice or more.

People can do whatever they want ... whatever makes 'em happy. I really don't care.

I don't care what you do either. But if you are measuring 5 psid across your filter steady state you are doing something wrong or your bearings are shot.


You're not following. My car puts out ALOT of oil volume ... so at full pump pressure there is enough oil flow to create 5 psid across a brand new filter. So ... with the built in 8 psi bypass setting in the engine's block, it only gives a measly 3 psi of "safety margin" for filter loading over the OCI ... and I routinely rev the heck out of this car, so the oil pump will be puttin' out major volume. If there is enough media loading to cause an extra 3 psid at full oil volume flow, then the filter is in danger of going into bypass mode. Get what I'm sayin' here?

Originally Posted By: flatlandtacoma
And if you don't like a manufacturer's recommendation fine, but don't make it sound like I recommended using a filter for more than 2 oil changes.

But you do recommend it if the manufacture recommends it. You said it above in one of your posts.

Every car has it's own characteristics. Most people probably wouldn't realize that some hi-pro GM cars have such a small margin on bumping into the bypass valve compared to other cars with the same pump volume because of the relatively low pressure setting on built-in block bypass valve. It's up to the owner to understand it and make the correct decision in terms of oil & filter use.

 

[electrolover]

i really hope for your cars sake if your running a filter 6-10k depending on your oci you are using a quality filter like bosch or M1. otherwise a filter is too cheap not to replace

 

[pavelow]

Originally Posted By: PurplDodge
Why would you? Oil filters are so cheap, so why not. Its only $7 at the most.
X2. This is one place people should not "cheap out" on with their vehicles.

 

[flatlandtacoma]

Originally Posted By: ZeeOSix
You're not following. My car puts out ALOT of oil volume ... so at full pump pressure there is enough oil flow to create 5 psid across a brand new filter. So ... with the built in 8 psi bypass setting in the engine's block, it only gives a measly 3 psi of "safety margin" for filter loading over the OCI ... and I routinely rev the heck out of this car, so the oil pump will be puttin' out major volume. If there is enough media loading to cause an extra 3 psid at full oil volume flow, then the filter is in danger of going into bypass mode. Get what I'm sayin' here?

I have no doubt that your bypass valve opens on the initial surge every time you start that engine with cold oil. But if you are seeing anywhere close to 5 psid with the oil warmed up and the system full I would be shocked. Please show me where you are measuring this 5 psid.

Quote:
Originally Posted By: flatlandtacoma
And if you don't like a manufacturer's recommendation fine, but don't make it sound like I recommended using a filter for more than 2 oil changes.

But you do recommend it if the manufacture recommends it. You said it above in one of your posts.

There aren't any manufacturers recommending using the oil filter more than two intervals. And if your manufacturer recommends changing the filter every oil change, then I do too.

 

[flatlandtacoma]

If your manufacturer recommends changing the air filter every 30k and you check it at 15k and it is clean, do you change it at 15k?

 

[Sayjac]

Holy thread revival batman. Got to love the dirty cloths/underwear analogies, never fails to surface in this topic discussion.

Relevance, nah.

As I said when this topic was first posted, since arriving at Bitog, I'm more open to changing the filter every other time. That said, while it seems clear a filter becomes more efficient with use, ie,, catches smaller particles, not convinced that following that following the Honda recommendation will make a hill of beans difference in the life of an engine. Since Honda specifically makes that "recommendation", imo if it was critical/important to engine durability, Honda dealers wouldn't change the filter each time with shop service.

That said, if one is comfortable with o/f change every other time and/or uses a mightyvac/oil extractor and/or the filter is in a pita position, that will work too, imo.

But me, with the stash of 14610/7317 apps and others I currently have, I'll changing it every time, including my Accord and the Civic I maintain.

 

[webfors]

meh... changing the filter every other OCI depends on the app and interval length. If we're talking about Subaru's 3750 mile OCI in Canada, running a filter for 7.5k is just fine.

If we're talking monster OCIs mandated by beautiful OLM gizmos, I would change the filter each time.

 

[ZeeOSix]

Originally Posted By: flatlandtacoma
Originally Posted By: ZeeOSix
You're not following. My car puts out ALOT of oil volume ... so at full pump pressure there is enough oil flow to create 5 psid across a brand new filter. So ... with the built in 8 psi bypass setting in the engine's block, it only gives a measly 3 psi of "safety margin" for filter loading over the OCI ... and I routinely rev the heck out of this car, so the oil pump will be puttin' out major volume. If there is enough media loading to cause an extra 3 psid at full oil volume flow, then the filter is in danger of going into bypass mode. Get what I'm sayin' here?

I have no doubt that your bypass valve opens on the initial surge every time you start that engine with cold oil. But if you are seeing anywhere close to 5 psid with the oil warmed up and the system full I would be shocked. Please show me where you are measuring this 5 psid.


You've been on this board since July 2006 ... there have been plenty of threads posted/referenced showing data/graphs of Flow vs. PSID with hot oil, so I'm kind of surprised you don't know this actually happens on hi-pro engines. Go search for Subaru oil system threads and you'll see what I'm talking about.

Most "free flowing" oil filters will create up to 5 PSID when hit with a high volume flow of hot oil. More restrictive filters might even have higher than 5 PSID when subjected to high oil volume flow.