Air Filters - Independent tests

[RedBrat]

For any of you that have any interest in air filter performance data, go to the link below. A quote from it is below.

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

 

“The AC Delco filter test ran for 60 minutes before exceeding the restriction limit while the AMSOIL and K&N tests each ran for 20 and 24 minutes respectively before reaching max restriction. In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms. Compared to the AC, the K&N “plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons.”

Just in case you are looking for long life from your engine.

[86subaru]

but the k-n you can wash out and use again , can you do this to other filters ?

[Ross]

the k&n may be reusable, but it costs 10-20 times the amount of others, and you still have to buy k&n oil (preferably).

[86subaru]

mine cost me 20 bucks shipped and it came with the cleaning stuff

[rallyruss]

mine cost me 20 bucks shipped and it came with the cleaning stuff

that means a stock filter should cost 1.00$ to 2.00$?

hmm... funny math here or somthing.

 

yeah I will stick with the K/N still. nothing against a good stock type filter though. Its about preferance.

 

K/N usually pays off in three washings for me.

[Ross]

funny math here or somthing.

 

no, not funny math, funny pricing! Over here in new zealand you can pay $100 for a K&N!!!

Standard filters here cost around $5-$10.

If i was into high horsepower, sure, i'd probably still get a k&n - even with the price.

[Myxalplyx]

I've never had an engine fail using a K&N air filter. I have 5 cars with K&N air filters on them. I never noticed any power loss or loss in performance attributed to dirt getting in. I've had my Outback Sport going on 8 years now and it's running stronger than ever (2nd engine though...my bad..hehe). Even still, no problems because of the filters letting in too much dirt or because of restriction.

 

I'm going to read up more on that site. I can't understand how something that is dirtier be less restrictive. I mean, how can air flow through more dirt/debris easier? Time to read!

 

 

*Edit* Looks like we have to do our own independant test to know for sure. "However, if a filter is using "better airflow" as their marketing tool, remember this....Does it flow better? At very high airflow volumes, probably. BUT, Our trucks CAN'T flow that much air unless super-modified, so what is the point? The stock filter will flow MORE THAN ENOUGH AIR to give you ALL THE HORSEPOWER the engine has to give. And this remains true until the filter is dirty enough to trip the air filter life indicator. At that point performance will decline somewhat. Replace the filter and get on with it."

I don't understand this point. If the Delco unit flows better than type 'B' air filter, why would type 'B' air filter flow better at high airflow volumes? What is considered 'high airflow volumes'?

[rallyruss]

wow 100 bucks for a K/N. I wolud pass on that too if I had to pay that.

 

please note that this is on only one type of vehicle. some OE filters. espically Diesel filters are well made. I agree on that. In this case I agree with the guy that for a duramax maby a K/N is not the best choice.

 

but this is no "unbiased report" and not all filters compare the same on every vehicle. I had a OE filter fail on my old RX once. never had that problem with a K/N. far more secure sealing area. not to mention it can handle some water from time to time.

[bratman2]

You need to read the whole test. All the paper filters and the amsoil filter were tested using coarse dust while the K&N was tested using fine dust, that is not objective testing. Further down they show the micron ratings and percents of coarse compared to fine dust and they are very significant differences. One would have to wonder why they dumped a finer dust in the K&N. I have two K&N filters installed in my vehicles now and a paper filter in wife's 2003 Legacy. I like K&N style filters and truely believe a paper filter probably does filter better if all things are equal, a bad seal will cause way more problems. Several years ago I had my wifes former Mustang serviced at a tire store and they installed a new air filter, next time I changed oil some 10k miles later(mobile1) I pulled the air filter out to tap the bugs and crap free. The air filter had been improperly installed so as not to seal, the inside of the housing on the throttlebody side was coated in dust along w/ the throttlebody itself. Sold the car 36k miles later w/ no engine failure and still ran great so go figure.

[4WDFrenzy]

Here is some info directly from K&N's website under "Facts." *Nothing has been changed*:Facts You Should Know About Air Filters

 

We believe the primary function of an air filter is to deliver both high airflow and superior dirt protection. We design our air filters to provide minimum restriction allowing high airflow into an engine. In the vast majority of cases increased airflow will increase engine performance measured by horsepower and throttle response (torque). The performance benefits of maximum airflow are clear, compelling and well documented. That is why so many professional racers are willing to run expensive vehicles with no air filter, as opposed to installing a disposable air filter. They are seeking the additional horsepower and throttle response needed to win the race.

 

We design our air filters to provide superior filtration of the contaminants that can harm your engine while maximizing the airflow characteristics of the filter in question. The ability of an air filter to protect your engine is generally measured using a testing procedure developed by the Society of Automotive Engineers identified as the SAE J726 procedure. We subject a sample of our filter designs to this test procedure using Coarse Test Dust, which includes particles ranging in size from less than 5.5 microns to 176 microns. As a point of reference, a human hair is approximately 50 microns in diameter. The result of the above test procedure is a specific air filtration efficiency number. This efficiency number represents the percentage of test dust retained by the filter and thereby kept out of an engine. Our goal is to design our air filters to achieve maximum airflow while targeting overall filtration efficiency at 98%.

 

 

<FONT face=Arial size=3>Because no two air filters are alike, the specific airflow and overall filtration efficiency will vary depending on the filter in question. However, you can rest assured that each air filter we sell, has been designed to achieve high air flow while providing superior filtration.

 

 

Maybe this info will help. Personally, I run a stainless steel mesh cone filter, that incidentally filters the same as a K&N without the need for the oil. I have had absolutly no problems with either(K&N and the Stainless Steel) filter(s).

[Ross]

In my opinion, this test is only confirming what most of us could have worked out for ourselves. That is, that for less flow restriction, you are going to sacrifice some filtration performance.

Just comes down to what you want - a paper filter will fiter out slightly more dirt, while a K&N will be less restrictive to flow.

[RedBrat]

You need to read the whole test. All the paper filters and the amsoil filter were tested using coarse dust while the K&N was tested using fine dust, that is not objective testing. .

Go back and reread it. The K & N was tested twice: once with the coarse dust and once with the fine dust. The results discussed in the text and in the graphs were those obtained with the coarse dust. With the fine dust, even more dust is passed on into the the engine. It was apples to apples.

 

The testing standard refered to on the K & N site is the old test number, but here it is refered to by it's international number (ISO#). This is identified in the comentary.

 

Racing engines don't always use filters because they are at the extreme edge and they aren't run over any length of time before they are rebuilt anyway.

 

In my opinion, if you want long life from your engine use a filter that gets 99.8% of the particles out rather than just 98%. It isn't neccessarily an OEM filter. For a new type that can get wet and survive and gets a higher percentage of the fines out of the air stream, look at the specifications on the new Donaldson PowerCore design. It's used in Ford Duramax Diesel and the Hummer H2. I am putting the Hummer H2 canister and filter on another vehicle of mine.

 

http://www.donaldson.com/en/engine/air/index.html

 

Take care.

[bratman2]

I did reread it and you are correct, that's what I get for trying to read something after working a 12hr night shift. At the same time one could wonder what does very small microns of dirt due when induced inside a combustion chamber and exploded. For now I'll leave the K&Ns on my F150 and Brat and stick to factory panel filters for the Legacy.

[stngllhm]

It's used in Ford Duramax Diesel and the Hummer H2. I am putting the Hummer H2 canister and filter on another vehicle of mine.

 

 

Take care.

ford does not have the duramax. ford has the powerstroke. the durmax is in the chevy and gmc trucks

[RedBrat]

ford does not have the duramax. ford has the powerstroke. the durmax is in the chevy and gmc trucks

You are correct! Sorry for the switch in names. It is Ford with the Power Stroke that is using the new Donaldson Filter (there are also Freightliner and John Deere tractor applications). They also have a retrofit kit for prior years Power Strokes.

 

Fine dust does the same thing coarse dust does. It causes internal engine wear. More dust equals more wear. Coarse dust just does it even faster. You will never get all dust out, but less equals longer engine life.

 

Because diesel engines operate at much higher compression ratios, any wear to the pistons or cylinders has a much more significant effect sooner than on a gas engine. That is probably why it was diesel folks that undertook this comparison test. I work in the agricultural equipment business which is a combination of diesels and dusty conditions so I guess I am just more sensitive to this issue than most. People lose jobs over one filter screwup in this industry! While gas engines can take a little more and survive, in my scheme of things I would like my engine to last as long as possible. I have just rebuilt the engine in the unit that is getting the Donaldson PowerCore Hummer air filter and I want it to last a long time.

 

To get free breathing and good filtration, I have oversized the filter relative to the original or the K & N that was on it.

 

One possible option would be to have a setup for offroading where water and maximum performance are issues and another for general street use to ensure long life. Quick change air filtration systems! Now that's a thought.

[stngllhm]

i thought that i would throw out the fact that on some new vehicles K & N filters void the warrenty