Lots of stuff on filters... thought I'd try and get a little more statistics on experience with K&N filters alone.

If I've set up the poll correctly, I'm looking for a breakdown which shows initial effect on performance, and longer term performance. As you all know if you've read even a small amount of the experience out there, that there are many different results ascribed to K&N filters.

 

One "result" from using a K&N that's not included in the is the amount of crap that they allow through, compared to the OEM filter.
They also, if improperly oiled (which they often are), allow oil through which can and does damage sensors.
I would never run a K&N out here in the SW with all the super fine dust that we have. Everyone that I know that has run them that has pulled their air tube off after running one for a while, has found it coated on the inside with fine particulates.
Simply isn't worth it, to me anyway, even if there were a minuscule power increase (though unlkely except maybe at WOT).


Best,
Fred

 

I have read this comment from others.. if that has been your experience, I'd have voted for option 2, as, if true, this would lead to a loss of performance long term attributable to the filter.

If that is not your direct experience, but reflecting what you've observed from others comments, then option 4.

I'd expect to pick up a few of those as the poll continues.

Thanks for your comment.

 

Loss of power due to breathing all the hot air from under the hood.

Improperly oiled filters let a lot of dirt thru.

Over oiled filters drip goo all over.


Amsol makes a 'dry' washable filter I'm thinking about getting to replace the K&N as well as ducting it so it breaths outside air only.

 

My '85 1st generation came with a K&N (purchased in '96. Not knowing any better, I have cleaned it with soap and water for 12 years now, once a year. No Oil.

The truck has always run great, and still does. I assume by cleaning it that way, that I'm not getting proper filtering. I drive 8 miles of dirt roads every day I use it, so I assume I've been putting the engine at risk. The dust on these roads is a fine powder.

Silly me... I'll check out the Amsol dry washable. I agree it makes no sense to use oil as part of the filter system, which, absent the instructions, is the reason it never occured to me to add oil. Thanks for the tip.

 

K&N have been around quite a while and there's no evidence that they cause harm to engines and there's still plenty in use so they can't be the bane of the filtering world.
I ran one on my turboed Eclipse for 6 years with no issues ever and as you know turbos have very little tolerance for dirt getting into them but of course my Eclipse was never off road.

On my Runner I've switched back and forth between the K&N and a OEM version and not really any noticeable diff in performance or MPGs and since cleaning is a chore somewhat I just stick with OEM in the end.

 

I had a K&N and noticed no difference, now I am back to OEM.

 

As I've said before personally I like the K&N product, I definitely noticed an improvement in performance. My '87 was a 22R with the old ring style filter and it defintely woke up with the K&N never noticed any powder of fine silica getting through even driving on dusty construction sites... MY '94 has a cone filter and there was noticably more pep after I switched over, still hav'ent seen any crud getting through, just remove and clean/re-oil with K&N kit once a year. And I love the little woosh sound you get from the intake...

 

The K&N didn't do anything but make my intake louder. I got tired of cleaning it and put a OEM back in. It's still sitting around here if anybody wants it.

 

ive been running a K&N for the past 6 or so years, pulled it out of my 99 runner that i totalled and put it in my 02. i clean and oil it once a year, never had a problem with dust getting thru it. i may switch to the amsoil or the true flow(?) whenever someone drops some $$ in my lap. i just like that i dont have to go out and buy a new paper filter every 15k, plus they give you that sticker that easily adds 5hp

 

A good handful of test (some "better" than others) have been done on K&N's and they all (all that I've seen) produced exactly the same results.

From one of them that was very weel done in a lab (I'll have to poke around some and find the original link):

"In the chart above it’s important to note the different test durations for each filter. 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."



Less scientific, but certainly real world.
This makes K&N's and Amsoil basically stink:

http://www.bobistheoilguy.com/airfilter/airtest3.htm


I've experienced the crap that it lets through on my own vehicle a handful or years ago when I ran one for a brief period of time.
Everyone that I know, first hand, that have run them have seen the same thing, the inside of their air tube coated with fine particulates that you don't see running an OEM style filter.



Fred

 

ive ran k&n filters in everything i own for the past 8 yrs. and have never had any problems to date. i dont like spending money so it is cheaper to buy one and clean it every few monyhs.

 

I thought you only had to clean K&N filters once every 50,000 miles. The intructions for one I had years ago was like that. If you clean it every year, you must drive a lot

 

I think if your vehicle is a street machine, K&N filters may flow more air when you are on the gas, but for offroading they are a bad idea for all the reasons listed above. When I first got my truck, I got a K&N FIPK no knowing what I know now from reading yotatech. This thing is LOUD, annoying, and not giving me any performance that I notice. It is an expensive POS.

 

You are right Fred! I read a thread on www.tundrasolutions.com about filters. Someone did a study and found that the OEM air filter was better and there was no HP gain with the K&N filter.

 

I like the k&n because u can clean it after a long day of wheeling if it gets muddy at all insted of buying a new oem every time

 

I've run the drop in filters in my '93 Accord, 1998 4Runner, 2001 4Runner, 2004 4Runner and I've got the K&N FIPK in my 1997 4Runner. I havent had any problems with particulates accumulating in the intake tube or MAF fouling. I've found most complaints stem from improper servicing. If you over oil them yes, they will muff your sensors and if you under oil them you will not get advertised filtering efficency. I believe the "dry" filter is by AEM, this seems like a good idea for those that want a bit more WOT and less maintenance headaches. For the ease of replacement and filtering quality the OEM filter is tough to beat.

 

I used one and it didnt do much, I got the same effect by removing the intake silencer.

 

Have a K&N on my 97; works great - I probably clean it more than most - only work of caution, don't over-oil cuz it'll get all over your MAF & that'll cause problems.....other wise product!

 

I think most who say it hasn't let anything more through than stock haven't had oil analysis done, or looked inside the plenum much less the heads to see. And I know for a fact the power gains are worthless...what little they MIGHT give isn't worth it.