Why Change your air filter?

[BlazerLT]

quote:

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Originally posted by Patman:
I don't think it's being cheap and it is true, the longer you leave your filter in, the better it filters. It's a proven fact. Only if the media gets damaged, will the filtration get worse.

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I think the benefits of having an engine not running rich due to insufficient airflow outweighs the advantages of running a plugged filter because it filters better.

I think people are getting a little neurotic about the filtration thing. An engine running inefficiently will cause more damage and sludge and acid than the damage caused from a clean air filter.

 

[Patman]

It has to get pretty plugged up before your engine will run rich though. Even when I changed my 80k (130,000km!) oem filter, my MPG did not go up, so that shows me I was not previously running rich.

 

[BlazerLT]

quote:

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Originally posted by Patman:
It has to get pretty plugged up before your engine will run rich though. Even when I changed my 80k (130,000km!) oem filter, my MPG did not go up, so that shows me I was not previously running rich.

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Of course you wouldn't see a difference seeing the computer may take up to 500kms relearning the new air/fuel ratio.

You can quicken the process up by resetting the ECM.

But realistically, not changing your filter because you think it will filter has much more drawbacks from improper combustion than any damage you will see from changing your air filter every 1 or even two years.

[ April 30, 2005, 12:29 AM: Message edited by: BlazerLT ]

 

[Patman]

quote:

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Originally posted by BlazerLT:

quote:

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Originally posted by Patman:
It has to get pretty plugged up before your engine will run rich though. Even when I changed my 80k (130,000km!) oem filter, my MPG did not go up, so that shows me I was not previously running rich.

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Of course you wouldn't see a difference seeing the computer may take up to 500kms relearning the new air/fuel ratio.

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And 500km later (and 40,000km later for that matter) the MPG did not change either. The old air filter was not causing my engine to run rich, that much I know for fact. I never saw high fuel dilution on my UOAs (a tell tale sign of running rich), my tailpipes were very clean (another good sign) and my quarter mile performance was always much better than other stock LT1 f-bodies (it ran 13.74 at 100mph in 100% bone stock trim, with that old air filter too)

 

[BlazerLT]

That filter was probably not very plugged at all.

We just have to watch telling people to not change their air filter seeing some will go way overboard and not change it ever thinking they are doing something good for their engine.

 

[Tosh]

I think there are good arguments for keeping the OEM air filter in much longer than the owner's manual states. After all, these are written only to cover the manufacturer's bum in case of owner neglect or other severe conditions. Which brings up this point: every car (and owner) is different and also sees different operating conditions. So, as y'all are obviously reading this forum, you are a proactive owner-operator and should make informed decisions based on your own experiences and local conditions (and err on the safe side).
But with that said, I don't think you should expect more than a cosmetic visual improvement (and warm fuzzy feeling) by vacuuming out the filter, and you might even be weakening the structure of the paper by the vigorous air movement. My opinion would be to knock out the leaves and bugs, but don't suck or blow on it with anything stronger than your mouth...

 

[lukey]

Reminds me of when I bought my '84 Honda Civic 4 cyl 1500 cc back in '87. It had 32k miles on it with the original air filter. When I changed the air filter the mpg improved by 2 mpg roughly.
Now that was a carburetor not fuel injection.

Lukey

 

[RedWolf4000]

I agree with you BlazerLT. Why would you leave an air filter in for 100k and have it be caked and clogged, probablly suffering gas mileage and creating a vacuum which wont allow the proper fuel mixture just so you can think you may have a more efficient filter.

They are very efficent clean.

Even a cotton guaze filter doesnt let enough dirt in to really damage your engine. It's only damaging in your minds and in a forth of the UOA's that you guys present (with K&N's), which are never very accurate, or so any difference that would do damage prematurely.

Do some of you honestly think that if you change your paper air filter every 15k that it does more harm then good? If this is the case you need to stop using this forum cause its making you crazy.

Is paper now not good enough at filtering your engines?

I had a paper air filter in one of my cars with a torn seal from being snagged on the box when it was closed, for 5 years. That engine has around 210k on it right now, a 92 lumina, runs great doesnt burn a drop.

Make a longer story short, the reason you should change your air filter is for efficiency.

 

[jason07-1zzfe]

quote:

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Originally posted by RedWolf4000:
I agree with you BlazerLT. Why would you leave an air filter in for 100k and have it be caked and clogged, probablly suffering gas mileage and creating a vacuum which wont allow the proper fuel mixture just so you can think you may have a more efficient filter.

It won't be in most cases.

They are very efficent clean.

Have you ever done SAE or ASHRAE tests on an air filter? Or seen test reports?

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[kenw]

RedWolf, your logic is lost on the OCP......

Using logic here is often like teaching pigs to sing: It sounds awful and just makes the pigs mad.....

 

[jason07-1zzfe]

It's not logic when it does not correlate with SCIENTIFIC TESTS.

It is BELIEVING WHATEVER YOU FEEL LIKE because you're too friggin arrogant.

 

[RedWolf4000]

Yes I have seen the reports. Are you refering the good clean paper air filter results, or the good cotton guaze air filter results, because there both good for the life of an engine way past the life of the chasis it sits on.

Not to mention that these test results, like the one from spicer, (which shows good filtration for paper and cotton as far as efficiency goes)can only be guessed that they are accurate. I would much rather believe the filtration efficiency stated by acdelco, fram, and K&N then I would from some guys buddy that has the proper equiptment to test the filters.

 

[RedWolf4000]

Your calling me arrogant? "Friggin" arrogant. Arrogant is sitting on a website and believing everything you read just because its on paper. Half the guys on this site love to play around with this stuff to much, which makes them take the smallest things and blow them up into problems. Comparing smells of oils, supports this. Fact is everything on this site should be taken with a grain of salt because, none of it has been proven.

Just because it is presented by Black Stone Labs who I do not support does not mean its factual in anyway.

You can take virgin oil and get it sampled at 3 different companies, and the UOA's will have very different results.

It's more arrogant to believe everything you read thats different then what "the man" says then to listen to what "the man" says.

 

[MN Driver]

quote:

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Originally posted by RedWolf4000:

You can take virgin oil and get it sampled at 3 different companies, and the UOA's will have very different results.

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This has been done with used oils at 3 companies, they came back incredibly close, a search will probably find that thread, it is recent. Used oil analysis results are a better indication of an oils capability than a VOA.

 

[jsharp]

quote:

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Originally posted by Patman:

quote:

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Originally posted by BlazerLT:

quote:

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Originally posted by Patman:
It has to get pretty plugged up before your engine will run rich though. Even when I changed my 80k (130,000km!) oem filter, my MPG did not go up, so that shows me I was not previously running rich.

---

Of course you wouldn't see a difference seeing the computer may take up to 500kms relearning the new air/fuel ratio.

---

And 500km later (and 40,000km later for that matter) the MPG did not change either. The old air filter was not causing my engine to run rich, that much I know for fact. I never saw high fuel dilution on my UOAs (a tell tale sign of running rich), my tailpipes were very clean (another good sign) and my quarter mile performance was always much better than other stock LT1 f-bodies (it ran 13.74 at 100mph in 100% bone stock trim, with that old air filter too)

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If the engine has a mass airflow sensor I don't see how the mixture will change by changing filters.

I believe the ecu should only need to be reset if you make enough changes to the intake that the available fuel trim isn't sufficient. I'd expect OBDII vehicles to show a check engine light if that were the case...

 

[George7941]

Fram has restriction gauges, part no. SP3789 and they are not expensive, about $50 Cdn, will be cheaper in the States. I installed them in my Ford pick-up and on a chevy diesel van at work. I used to change air filters every 15000 mi, now, going by the gauge, I only change them every 25000 mi. I think Delco can supply these gauges too.