Very Interesting Air Filter Test

100R1 · May 9, 2005

I found This Test article. More Food for thought

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

MrQuadrasteer · May 9, 2005

Cool. Thanks for sharing.

Very interesting....

topo4u2 · May 9, 2005

Does this mean that the factory AC Delco air filters are the only worthwhile filters to put in our trucks?

JDeere7296 · May 9, 2005

I know tests don't lie, but do you guys think that a stock paper filter really flows better than say a aftermarket oiled cotton media or foam media? I have had a K&N drop in filter in my last two chevys, and I have always keep them clean and oiled. I have never noticed even the slightest bit of dust in my intake tube or around my TB.

I don't know, what do you guys think?

JRW68 · May 9, 2005

I know tests don't lie, but do you guys think that a stock paper filter really flows better than say a aftermarket oiled cotton media or foam media? I have had a K&N drop in filter in my last two chevys, and I have always keep them clean and oiled. I have never noticed even the slightest bit of dust in my intake tube or around my TB.

I don't know, what do you guys think?

<{POST_SNAPBACK}>

The test makes sense, the less restrictive filters dont filter as well.

I have never been a big fan of alot of aftermarket filters but I think this verifies the company's claims, they do flow better when clean. Thats why K&N and Uni are cleanable.

As for them not filtering quite as well... you have to ask youself what size particle is going to cause damage... Ive seen numerous industrial motors run without filters and run fine for thousands of hours. Im not recommending it but I wouldn't be concerned with a small amount of dust getting by your filter.

Do I feel that K&Ns arn't worth it... depends on the person, if you look at the fact you should never have to buy another filter again, I can certainly see the pay off in the long run. But if you dont mind spending money on an OEM filter every once in a while, an OEM isn't a bad way to go.

Just my 2 cents

Bish · May 9, 2005

I'll offer my 2 cents on the topic. Bear in mind I've had an 01 Tahoe for over 140K so far. I have had the K&N FIPKII on since around 20K.

First off, I would agree that paper filters better than oiled cotton (K&N). THrough oil analysis, I have tracked silicates (a good indication of filter capability) at every oil change (5,000mi). Tests went from averaging around 8PPM to 10PPM when I changed to the K&N. That says that more partculate matter is definitely getting through. However, I've been told that until silicates get above 15PPM, there is no difference to the engine. Even though several knowledgeable people have told me this....is it true???

Second, while I have no actual dyno numbers, I can say throttle response is DEFINITELY better with the K&N. I swapped them back and forth repeatedly and there is definitely an improvement. That improvement may be completely due to the straight intake tube versus the cluge oem intake with the chamber for keeping quiet but it is definitely an improvement.

Third, I believe the clean/oil process is CRITICAL and if done improperly could lead to problems. If under-oiled, could greatly reduce filtering. If over-oiled, could foil MAF sensor or pass oil into intake.

Fourth, it just plain sounds better with an aftermarket intake versus stock.

I'll boil my opinion down to these statements.

If running a stock intake and stock exhaust, there is no real benefit to using a non-paper filter IMO.

If running an intake and exhaust, I think a better flowing filter will help.

If properly cleaning and oiling your filter, there is little risk of any damage.

I've got over 142K on my Tahoe now and according to the oil analysis guys, the engine is wearing like it has 30K on it. I'll accept that as adequate evidence I am not doing damage to the motor.

Not trying to start a flame war...this is just my opinion. One thing I like about this board is you hear ALL sides of the discussion.

JDeere7296 · May 9, 2005

Thats kind of what I was thinking, if properly maintained the K&N filters should be fine, there are alot of people who buy K&N so if there was a problem with filtering I would think we would hear a lot more than we do. Its just I had never seen a test where K&N do so poorly than other filters and was a bit concerned with the results.

May 9, 2005

I love this stuff (throwing numbers around).

First, how much dirt a filter can hold before it reaches full restriction tells you what?

Answer: how often it needs to be cleaned (cotton/oil) or replaced (paper). If you assume we care then you must also assume we do our maintenance. Once you establish that we do maintenance, how often we do it is irrelevant. (note the differences in our oil change frequencies).

Argument: I would venture to say that those who use cotton/oil type filters check and clean their filter far more often than those who use paper. Why, because they tend to fall in the "do it yourself" category more often.

Conclusion: Will you not be better off with a clean cotton/oil filter than a dirty paper one?

Second, why were these test done at 350CFM air flow? If my figures are right a 5.4 liter engine (at 100% efficiency) can flow 524 CFM of air at 5500rpm. 350 CFM would convert back to about 3673 rpm. Where would that speed fall in our daily driving? Either do the test at race speeds to show maximum effect or at highway or average speeds which would be somewhere in the 1800-2200 rpm range or about 190 CFM.

Third, the test was done while maintaining the airflow at a constant volume. Since the purpose of the cotton/oil type filter is to increase that volume you must allow the increase to occur. Take them off the test bench and put them on a real engine. Measure the restriction and airflow volumes and see how far the graphs separate when you reach higher RPM levels.

Fourth, I'd like to know how much dirt was passed through each filter AFTER it reached its maximum loading. While I contend that we would not let it reach that point it is still a useful figure since it shows efficiency across the range. You'll note that even after the filters were "loaded" the cotton/oil type filter still passed more air at lower restriction than the paper filter.

...why were there figures for "fine dust" for the cotton/oil filters but not for the paper ones? Is this supposed to imply the paper filters have the SAME efficiency for both?

don't get me started

Meatco1 · April 26, 2007

Hello:

If anyone has a copy of this report, I for one would love to read it! The posted link is dead, so unless someone here has a full copy, it is gone forever!

Thanks,

Richard

J.B.R. · April 26, 2007

I agree the link does not open. When I was looking for a new air filter for the Yukon 99 5.7l. The stock oem filter was rated at 250cfm, which seems a little lite. So I went with the Dry Amsoil nanofiber. It has the best capture rate and 3 times the flow. Made by Donaldson filters. I LOVE it.

Silverado4x4 · April 26, 2007

It doesnt open because the original post is almost 2 years old.

redvett · April 26, 2007

Here is an air filter test.

http://www.duramax-diesel.com/spicer/index.htm

Meatco1 · April 27, 2007

Here is an air filter test.
http://www.duramax-diesel.com/spicer/index.htm

Thank you, that was the link I have been looking for.

Thanks again,

Richard

allroads · April 29, 2007

I'll offer my 2 cents on the topic. Bear in mind I've had an 01 Tahoe for over 140K so far. I have had the K&N FIPKII on since around 20K.

First off, I would agree that paper filters better than oiled cotton (K&N). THrough oil analysis, I have tracked silicates (a good indication of filter capability) at every oil change (5,000mi). Tests went from averaging around 8PPM to 10PPM when I changed to the K&N. That says that more partculate matter is definitely getting through. However, I've been told that until silicates get above 15PPM, there is no difference to the engine. Even though several knowledgeable people have told me this....is it true???

Second, while I have no actual dyno numbers, I can say throttle response is DEFINITELY better with the K&N. I swapped them back and forth repeatedly and there is definitely an improvement. That improvement may be completely due to the straight intake tube versus the cluge oem intake with the chamber for keeping quiet but it is definitely an improvement.

Third, I believe the clean/oil process is CRITICAL and if done improperly could lead to problems. If under-oiled, could greatly reduce filtering. If over-oiled, could foil MAF sensor or pass oil into intake.

Fourth, it just plain sounds better with an aftermarket intake versus stock.

I'll boil my opinion down to these statements.

If running a stock intake and stock exhaust, there is no real benefit to using a non-paper filter IMO.

If running an intake and exhaust, I think a better flowing filter will help.

If properly cleaning and oiling your filter, there is little risk of any damage.

I've got over 142K on my Tahoe now and according to the oil analysis guys, the engine is wearing like it has 30K on it. I'll accept that as adequate evidence I am not doing damage to the motor.

Not trying to start a flame war...this is just my opinion. One thing I like about this board is you hear ALL sides of the discussion.

Did you notice a difference in gas mileage as well?

stregaiq440 · July 24, 2007

Glad to see a good test done on this. My experience has led me to believe that KN has great marketing and poor filter performance. They should be stomped to death on the garage floor!