Changing filter every other OCI?

[Gary Allan]

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There was a UOA not long ago where the filter was changed every other OC and the UOA was stellar, albeit it was a honda uoa. Terry also approved the filter change interval and also made the comment that the filter becomes more efficient. I would definately follow his advise.

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That certainly may be, but I will stick to changing my filter at the time of the oil change. At some point the efficiency will go down. Does the UOA predict when this will happen?

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Surely do whatever you feel is right. I've personally studies 10k old filters and they weren't nearly saturated. What you don't perceive is the capacity of a common filter in a modern combustion environment. The holding capacity is well in excess of any factory recommended level if adhering to the factory format.

The media efficiency never goes down ..it only improves. What can occur, and this is still way out there in terms of when this will occur, is that differential pressure across the media will cause whatever bypass mechanism to be employed. Now this occuring due to loading is a very substantial mileage. Now it will exacerbate cold start/oil pump in relief/transitional peaks/prewarmup type bypass activity ..but this too is highly over rated in my observations for how often it happens ..and how long it lasts. Even with a 10k old filter with 20w-50 oil in a subfreezing starting temp I didn't reach the bypass threshold and had very little static PSID after warmup. Even in a "half the distance to the goal line" type deminishing return for mileage added ..this filter, a PureOne, would have been good for 15k.

FWIW

 

[bob_ninja]

So if the filter type/size hasn't changed and engines haven't changed that much, then why is it suddenly possible to use the filter for twice as long as before?
I am not sure what "media efficiency never goes down" really means???? As particles are caught in the media, less open pores are left remaining, hence less oil flow. In the extreme case bypass kicks in, which is effectively filter failure. I am concerned that in such a small filter volume one can pack only so much media surface.

BTW, doesn't motor age also affect filter change interval? I would guess that 2x rule might be sufficient for 100K or less engines, but perhaps not for older 100K+ engines.

 

[RD400]

OK, how do you drain a filter with anti-drainback valve? I've 'drained' such a filter and then cut it open only to discover there's still about 3 ounces of (dirty?) oil remaining.

 

[delacerda]

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OK, how do you drain a filter with anti-drainback valve? I've 'drained' such a filter and then cut it open only to discover there's still about 3 ounces of (dirty?) oil remaining.

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I use a small screwdriver and insert it into one of the inlet holes. This seems to drain out most of the oil.

 

[Gary Allan]

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So if the filter type/size hasn't changed and engines haven't changed that much, then why is it suddenly possible to use the filter for twice as long as before?
I am not sure what "media efficiency never goes down" really means???? As particles are caught in the media, less open pores are left remaining, hence less oil flow. In the extreme case bypass kicks in, which is effectively filter failure. I am concerned that in such a small filter volume one can pack only so much media surface.

BTW, doesn't motor age also affect filter change interval? I would guess that 2x rule might be sufficient for 100K or less engines, but perhaps not for older 100K+ engines.

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Engines have changed a lot. You must have been born with fuel injected engines not to know of these evolutions. The "every other" filter change method has been around in some cars since the late 70's if you used mileage as the criteria for your OCI.

So ..it's not "sudden" and engines have continually changed to produce less combustion byproducts. Unleaded fuel alone constituted a 1000 mile increase in my OCI on my 1975 SBC (which didnt' require unleaded fuel).

Just because some pores are blocked doesn't at all mean that flow is reduced. Flow would tend to accellerate through the remaining pores. The basic concept is that you have smaller pores and larger pores. Larger pores are, initially, going to see more oil pass through them ..and will then trap more particles. This will leave the smaller pores carrying more of the flow later on in the filter's usage.

As I said, but will repeat, even very long use filters (10k) showed no substantial bypass action even under extreme conditions.

As far as "small filter" syndrome goes, you're not alone. This is a common problem. You can be cured if you can begin to accept that there is that much less "stuff" produced to tax even the tea cup size filters. I tested a PureOne (a fine filter) that was the size of a PH3614 ....and I kept waiting for it to accumulate any PSID (pounds per square inch DIFFERENTIAL). I thought that my differential guage was broken. I got so annoyed that I then installed the 10k used filter in order to see results.

Now that's not to say that a larger filter can be of NO benefit. It just means that you aren't in jeopardy of reaching holding limits with a smaller filter. It's the least of your worries.

You don't have to raise the bridge ....they lowered the river long ago.

 

[CivicFan]

On my 03 Civic, I replace the oil filter at every oil change, too. But my OCI-s are 1 year/10,000 miles with 0W-20 Mobil1 oil.

 

[Hermann]

If I went to the trouble of getting to the PITA filter location on the latest generation Accord 4-cyl, I would surely change it. This is a horrible location, when you have your arm and hand bent just so to get to it, you have no leverage.

 

[4esorselrahc]

Okay. So I'm a little more convinced that changing the filter every other OC is acceptable. But it just seems to me that putting a fresh good filter on at every change would be better no matter how you look at it. I have no problem spending a little bit of extra cash for the new filter. Fresh oil is going in, so why not a clean filter?

 

[Gary Allan]

Well, by all means, do what makes you feel good. You have to have confidence in your methods. The cost difference isn't much ..nor is the difference in realized benefit in terms of wear (or non-wear). We're shaving crums here into smaller crums.

For example, a European trucking company did a cost/benefit analysis on using tp bypass filters versus regular oil changes. The found that although they saved lots of oil, the savings only added up to $81 over the same 8 years of ownership. It was mainly due to labor rates and the cost of the right size TP for the filters.

The longevity of the engines was never taken into account since they were always traded in @ 8 years. Now if they had kept running the same trucks and ran a cost analysis beyond that point ..there may have added benefit in avoided costs over units maintained the conventional way.

So, unless you're the type that can keep a car into the 250k+ range ..and maintain the rest of the car in the same manner, you're not going to alter the engine's longevity in your ownership. You may alter its condition marginally when you dispose of it.

Most Amsoil dealers will tell you that it would be a tough sell for their bypass filter setups based on realized benefit. The next owner of the vehicle will usually reap the rewards and no value premium will be assigned to it because of that type of care. :shrug:


If you get where I'm coming from here

All that I'm trying to tell everyone is that there's nothing negligent or harmful to doing an every other OCI filter change if the conditions are appropriate. Some sensible limitations do apply.

 

[bob_ninja]

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So if the filter type/size hasn't changed and engines haven't changed that much, then why is it suddenly possible to use the filter for twice as long as before?
I am not sure what "media efficiency never goes down" really means???? As particles are caught in the media, less open pores are left remaining, hence less oil flow. In the extreme case bypass kicks in, which is effectively filter failure. I am concerned that in such a small filter volume one can pack only so much media surface.

BTW, doesn't motor age also affect filter change interval? I would guess that 2x rule might be sufficient for 100K or less engines, but perhaps not for older 100K+ engines.

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Engines have changed a lot. You must have been born with fuel injected engines not to know of these evolutions. The "every other" filter change method has been around in some cars since the late 70's if you used mileage as the criteria for your OCI.

So ..it's not "sudden" and engines have continually changed to produce less combustion byproducts. Unleaded fuel alone constituted a 1000 mile increase in my OCI on my 1975 SBC (which didnt' require unleaded fuel).

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Clarification:
My time frame is the past 10 years. My oldest vehicle is a Civic CX 1995 (Canada) with recommended 7.5K OCI and filter change for every oil change (severe service is 3.75K).

I cannot find it anymore, but seem to remember a discussion about current recommendation for 10K OCI, and filter on 2nd change (so 20K). Correct me if I am wrong.

Now the 7.5K OCI for the little 1.5L engine (assuming dino) is, how should I put it???? .... NUTS
For the initial 7 years I always went to the dealer which always placed the sticker to come back in 3K (which is acutally reasonable as we are supposed to follow severe schedule).

So in the past 10 years they changed OCI from 7.5K to 10K = +33%
For filter from 7.5K to 20K = +166%

In 10 years I would call that a very big change relative to engine technology improvements.

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Just because some pores are blocked doesn't at all mean that flow is reduced. Flow would tend to accellerate through the remaining pores. The basic concept is that you have smaller pores and larger pores. Larger pores are, initially, going to see more oil pass through them ..and will then trap more particles. This will leave the smaller pores carrying more of the flow later on in the filter's usage.

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Back pressure will increase. Oil flow will remain constant so long as the pressure can keep up and maintain flow through smaller number of non-blocked pores. At operating temp I would assume that flow would be ok due to low viscosity. However, at 0F and much higher viscosity oil flow is already too low and filter that is too dirty doesn't help.

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As I said, but will repeat, even very long use filters (10k) showed no substantial bypass action even under extreme conditions.

As far as "small filter" syndrome goes, you're not alone. This is a common problem. You can be cured if you can begin to accept that there is that much less "stuff" produced to tax even the tea cup size filters. I tested a PureOne (a fine filter) that was the size of a PH3614 ....and I kept waiting for it to accumulate any PSID (pounds per square inch DIFFERENTIAL). I thought that my differential guage was broken. I got so annoyed that I then installed the 10k used filter in order to see results.

Now that's not to say that a larger filter can be of NO benefit. It just means that you aren't in jeopardy of reaching holding limits with a smaller filter. It's the least of your worries.

You don't have to raise the bridge ....they lowered the river long ago.

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My cheap little Civic has no instruments t show me what is going on. How would I know how much life is left in the filter? Indeed I use my filters for 1.5 oil OCI (leave old filter in during off-season storage) but I am blind as to how much longer a filter can be used for after the 1st oil change.

 

[tripleM]

I see no problems with all the evidence shown here that every other filter changes are ok to do.

But if you are going through the trouble of getting underneath the car & taking the filter off to drain the old oil...you might as well change the filter esp is most of us can get filters for ~ $3 around here.

Too little to not provide extra assurances.

 

[Laminar Lou]

At what point though do you need to change the filter because the media itself has degraded and there is risk that the media breaks off? I have always been concerned that the paper filters would deteriorate over time and eventually crumble. How about synthetic media? I don't put a lot of miles on my vehicles so I don't think I would chance 10K on my truck (which would take 2 years to accomplish), or even 3K on my motorcycle (that could take 2 or 3 years to accomplish - gosh I need to ride more

)

 

[caprice_2nv]

I just paid $3.91 Canadian for a Wix filter for my 307 Olds V8 the other day. Seems hard for me to justify leaving a $3.91 filter on there.

 

[Gary Allan]

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At what point though do you need to change the filter because the media itself has degraded and there is risk that the media breaks off? I have always been concerned that the paper filters would deteriorate over time and eventually crumble. How about synthetic media? I don't put a lot of miles on my vehicles so I don't think I would chance 10K on my truck (which would take 2 years to accomplish), or even 3K on my motorcycle (that could take 2 or 3 years to accomplish - gosh I need to ride more

)

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There's sensible limits to the practice, Lou. Typically if you're using mileage ..then it works. If you're using time, typically it doesn't. If you're doing 15k a year with a 7500mile OCI ..then you're not getting moisture and fuel and all the other things that can produce too many contaminants ..or degrade the media. You're operating, to a very high %, in the sweet spot for everything (oil, engine, and filter). If, OTOH, you're doing 3 miles a day ..ect ..then it just doesn't work.

I'd say that I'd probably do this for any car that did around 10k or more a year and did 6 month (+/-) OCIs.

 

[toocrazy2yoo]

I use the 24458 Purolator, half again as big as the specc'd 14459 for my Hyundai. I'm doing around 3-4K/month, almost all of it parkway/interstate with 5-7.5K OCI. My oil is still clean when I change it, and I've cut the filters open after 5K and they're like brand new inside. So, I drain em, clean off the gasket boss and throw that thing back on for another 5K. We're just not loading these filters up very much, at least, with a new car, I'm not. While not scientific, grabbing hold of the filter immediately after startup, it flows hot right in lockstep with engine warmup, so I'm surely not losing flow through the thing.

IMHO, folks buying these lovely PureOnes, Amsoil, Donaldson, and WIX/NAPA filters are really wasting a good filter tossing that thing after a lousy 3-5K OCI. Again, assuming a healthy, clean running mill.

 

[Patman]

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I just paid $3.91 Canadian for a Wix filter for my 307 Olds V8 the other day. Seems hard for me to justify leaving a $3.91 filter on there.

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Where did you find it so cheap? The Wix filter I just put on my Corvette cost me over $11 at NAPA.

 

[JavaMan]

I wouldn't bother changing my oil without changing the filter. It's like not washing your dishes before you serve in them again. New oil flowing through a dirty filter just doesn't make any sense.

 

[Patman]

If someone is doing 3k oil changes though, they could easily change the filter every 6k. The oil left in that old filter isn't even close to dirty yet.

 

[FleetFilter.com]

I run Royal Purple oil and I chage my filter every 4,000 miles, and add a quart of oil. I would rather put a clean filter on there, but that is just me.
Bryan

 

[caprice_2nv]

Patman, I bought the Wix at a local Napa store. The 307 Olds in the Caprice has a smaller than average diameter filter, it's a lot smaller than my small block Chevy filters, or the filters for my 350 and 455 Olds V8's. I paid about $5.60 for the Napa Gold for my Ford 302 filter and it's about the same size as the SBC filters. I'm not sure about the LS filters though?