Keep K&N or NOT ?

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So I have a 2005 Subaru Legacy Wgn, with the 2.5 single over head cam.
I got this car about 6 years ago, first thing I did was drop a K&N air filter into it !
Well, sad to say I haven't looked at that filter in years, well I just did , and really not too dirty !
So I have the cleaning and re-oiling kit, been inside my house for years and the cleaner doesn't feel like being pumped out of the bottle.
So here is were the "fun" begins.
I posted on the Ultimate Subaru forum and asked is there another cleaner I can use, got no real answer, but I did get a lot of pushback on the K&N filter, lots of people saying just dump it !
I guess the thought is that when you clean and re-oil it, the chance that you might get oil on the MAF sensor isn't to be fooled with !
I just saw the video below that I found here.
I just watched the video below were this guy is testing filters of different types on a dyno, then real world.
And yes it's a Subaru and yes it's a K&N filter too.
I'm not so much interested in the performance results, but what he says at the bitter end of this video, he talks about the charcoal filter that is there . 

I find the idea ridiculous that the oil from the K&N filter can migrate pass this panel and get to the MAF sensor !
https://www.youtube.com/watch?v=GS69owXpGdY

So if I dump it, then I'm finding that is a sea of options other than good old OEM paper replacements !
UGH!
 
I put a Spectre filter a knock off of a K&N on the Sentra.
I run full syn oil for 10K.
I noticed the oil was black at about 4K.
I switched back to a paper filter and the oil still looked almost new at 4K.
So I'm thinking the Spectre filter was letting in more dirt.
Keeping the oil cleaner is more important than any gains made by the Spectre filter,gains I didn't see anyway.
It's a Sentra,not going to be a super car with any filter LOL.
 
Only you can decide what to do. I can't think for you. I would have never bought the K@N. They have their purposes though.
 
K&N flow a little more air because they filter a little more poorly.
A little more HP and torque but you will never feel it.
I would use a quality filter (not a cheepie) and be done with it.
You can always keep the K&N in your garage.
 
Originally Posted by JeffKeryk
K&N flow a little more air because they filter a little more poorly.
A little more HP and torque but you will never feel it.
I would use a quality filter (not a cheepie) and be done with it.
You can always keep the K&N in your garage.
I doubt you will see any power gains at anything but WOT or increased MPG from a drop-in filter. The K&N CAI with the large cone filter might give you a few hp but you could probably make your own CAI with a paper filter for similar gains.

K&N is all marketing from when the layman could not modify computer controlled cars in the 90s.
 
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Everyone knows that it's the K&N sticker on the car that makes it go faster and not the air filter itself.
lol.gif
 
Originally Posted by SubeeTedII
Leaning toward one of those MAHLE filters . Trying to find out more about them, like lifespan. I guess MOPAR uses them as OEM filters for Hellcats !

Rock Auto carries Mahle.
 
Originally Posted by JeffKeryk
K&N flow a little more air because they filter a little more poorly.
A little more HP and torque but you will never feel it.
I would use a quality filter (not a cheepie) and be done with it.
You can always keep the K&N in your garage.


That's only if the factory filter is undersized for the application. If you've got a restriction gauge and it doesn't pull vacuum at WOT, the K&N is giving you nothing other than poorer filtration.
 
I was an avid K&N user until I joined this site. There was a member (I don't remember his name) that would throw out a comparative filtration statistic in favor of the paper filter every time one of these types of threads would come up. I tried to ignore it and write it off, but his relentlessness on every single thread caused me to do some research and he was right. I pulled the K&N out of everything I owned and went with paper from that point forth. I don't hate K&N at all, but they have their place and the usage scenarios that my vehicles are primarily in aren't optimal for K&N.
 
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I have been a K&N user for 20 years. Trying to squeak out every bit of MPG. K&N says over oiling by the user could cause MAF sensor oiling but I had MAF sensor oiling issues with a factory new K&N in my Ranger. Last year I did a lot of research on these types of filters. Yes, they will flow better than paper. At WOT which I rarely do. In the Spring I changed all my K&N filters for the paper ones (I kept the paper filters). I haven't noticed any change in MPG or performance.
 
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