K&N Drop-in vs. OEM

I don't think anyone's going to notice this thread since it's in the NA section but I'm going to post it anyway. Wondering if anyone had any experience with the K&N drop-in air filters? Are they any better than the OEM filter in terms of performance and MPG? I found them for $20 online so possibly cheaper than an OEM one from the dealer.

 

Show some NA love.

There's a few of us NA's out there

 

I've had a K&N drop-in for the last year or so.. I also removed the silencer at the same time, so I noticed a definate improvement on acceleration response, but that might be more due to the air flow then the filter.

 

Had good luck with the filter, and it's nice to clean as opposed to replace, but I haven't noticed any real measurable differences.

 

Just looking at the OEM vs the K&N, the K&N looks to be much higher quality, and if you run a compressor through the 2 of them, the air flow is much higher through the K&N. For the money, I would definately go with something other then OEM.

With the increase in 3.0R owners you will not be on your own for long.

 

I have a 99 Legacy SUS and I jsut recieved by K&N filter today! Not sure if we willget it put in tonight but I will let you know if we can tell any difference. I am sur eyou are more interested in 2005-2008 Legacy feedback though.

i have to say i am a tad dissappointed. No michigan M on your avatar. Your going to have to fix that mayne.

 

As far as the filter goes. If you can get them for that price then get one. You wont notice a whole lot. Get a tad bit louder under WOT. But nothing that is going to make you say OMG this filter Is tEh ShIt. nothing like that. But still a respectable mod over the OEM filter.

 

Bump for updating your avatar for another Big M fan. Hail to the VIctors!!!

^ there...happy now? i thought about using the M a while ago but i decided to remain humble instead. since you mentioned it, i might as well show some school spirit!

 

anyway, i'm surprised to see replies so quickly! so the NA section isn't totally dead! instead of going all out to get a $200 CAI, i think i might just go with a $20 K&N when it comes time to replace the OEM one (at 30k miles, right?).

 

With the increase in 3.0R owners you will not be on your own for long.

 

I have a 99 Legacy SUS and I jsut recieved by K&N filter today! Not sure if we willget it put in tonight but I will let you know if we can tell any difference. I am sur eyou are more interested in 2005-2008 Legacy feedback though.

 

please keep us posted!

Boosted my gas mileage from 29.5 hwy to 32 mpg hwy.

There's a few of us NA's out there

 

I've had a K&N drop-in for the last year or so.. I also removed the silencer at the same time, so I noticed a definate improvement on acceleration response, but that might be more due to the air flow then the filter.

 

Had good luck with the filter, and it's nice to clean as opposed to replace, but I haven't noticed any real measurable differences.

 

Just looking at the OEM vs the K&N, the K&N looks to be much higher quality, and if you run a compressor through the 2 of them, the air flow is much higher through the K&N. For the money, I would definately go with something other then OEM.

 

i'm a little scared to remove the silencer because it might mess up the pressure inside the intake box. more air flow is nice but i hope the K&N is also filtering the dirt properly.

Boosted my gas mileage from 29.5 hwy to 32 mpg hwy.

 

seriously?!

 

edit: what about city?

btw, [ame=http://www.amazon.com/K-N-33-2304-Replacement-Filter/dp/B000COC0GQ/ref=pd_bbs_sr_1/104-0128097-0676778?ie=UTF8&s=automotive&qid=1186435575&sr=8-1]Amazon[/ame] has it for $18.82, buy something else that you need to make the total amount go over $25 and get free shipping.

 

i used a charity's referral link to place my order. thought i should help out the poor kids.

yes much better. be PROUD forget humble. We are going all the way this time.

 

http://i72.photobucket.com/albums/i171/Crucifix79/michiganfl.jpg

also with you having the " i " i left my intake silencer in. Didnt do anything with the " I " but make the bottom end fall on its face. put it back in and i had low end. Didnt really notice a whole lot with the filter itself. Maybe just a tad bit better MPG. but couldnt be by a whole lot.

First post here, new 08 Legacy Limited owner...

Best price on any K&N I've ever seen. Just ordered it with the cleaning kit as mine is about all used up.

yes much better. be PROUD forget humble. We are going all the way this time.

 

http://i72.photobucket.com/albums/i171/Crucifix79/michiganfl.jpg

 

are you a student there too? i once saw a modded Legacy parked outside of the Dennison Bldg.

 

First post here, new 08 Legacy Limited owner...

Best price on any K&N I've ever seen. Just ordered it with the cleaning kit as mine is about all used up.

 

Welcome to the forum!

btw, Amazon has it for $18.82, buy something else that you need to make the total amount go over $25 and get free shipping.

 

i used a charity's referral link to place my order. thought i should help out the poor kids.

oh, so tempting. i have the avo. hmmmmmm....

oh, so tempting. i have the avo. hmmmmmm....

 

don't be greedy, you already have a turbo.

 

now i'm a bit concerned about the level of filtration these K&N filters provide. i mean K&N claims that they use ISO standards (even stricter than SAE's) to make their filters but do they really provide the same kind of protection as Subaru's OEM air filters? a little HP increase and/or mileage improvement is definitely not worth risking the longevity of an engine. is it true that IF the K&N filter lets more harmful particles in, you can fix that by changing oil regularly?

A while back I read about a test performed on many of the so called performance filters out there, including the K&N:

 

http://www.bobistheoilguy.com/airfilter/airtest1.htm

 

In summary their was very little advantage over the stock PAPER filter. An air filter is primarily a filter and should be chosen for it's filtration ability. Many of these performance filters do let more dirt into the engine than a paper filter. You can't offset this with oil changes because this dirt is going directly into the cylinders... not someplace you want ANY dirt. I for one am not going to put something that has oil all over it into my intake up stream from my MAF meter. I have had problems in the past with a K&N fouling my MAF sensor and I am not going to mess with it again. The only advantage a K&N really has over paper is longevity, but with the costly and time consuming cleaning and re-oiling process that is really a wash. You would have to keep a K&N a very long time and/or drive a lot of miles for it to make financial sense.

 

OEM or high quality aftermarket paper for me.

seriously?!

 

edit: what about city?

Lets see. I was getting about 20 before. I avg around 21/22 in the city. Can do 24 if I coast alot.

I dropped a K&N in my 08 3.0R when I got it. Am not sure of performance differences since I didn't get exposed much to the OEM filter. But my past experience with K&N in other vehicles has been that it's opened up airflow slightly. This past weekend during some spirited mountain driving in Sport Sharp mode, I averaged 24.5 MPG over the span of the whole tank. Good luck!

A while back I read about a test performed on many of the so called performance filters out there, including the K&N:

 

http://www.bobistheoilguy.com/airfilter/airtest1.htm

 

In summary their was very little advantage over the stock PAPER filter. An air filter is primarily a filter and should be chosen for it's filtration ability. Many of these performance filters do let more dirt into the engine than a paper filter. You can't offset this with oil changes because this dirt is going directly into the cylinders... not someplace you want ANY dirt. I for one am not going to put something that has oil all over it into my intake up stream from my MAF meter. I have had problems in the past with a K&N fouling my MAF sensor and I am not going to mess with it again. The only advantage a K&N really has over paper is longevity, but with the costly and time consuming cleaning and re-oiling process that is really a wash. You would have to keep a K&N a very long time and/or drive a lot of miles for it to make financial sense.

 

OEM or high quality aftermarket paper for me.

 

The problem arises when people improperly oil their K & N filter. This is done at intervals of 100,000 miles, which you would use 3-4 paper filters in that time. A K & N wire filter is really no different that an intake cone which people use on their engines all the time to gain performance.

 

My best reccomendation. Use the K & N filter for 100,000 miles. You will have gotten your moneys worth of it by not having to replace paper filters and the fuel economy boost will also put more money in your wallet. The sound coming from under your hood might also trick people into thinking you have a short ram intake under there.

use AEM's dry filter. No oils.

A while back I read about a test performed on many of the so called performance filters out there, including the K&N:

 

http://www.bobistheoilguy.com/airfilter/airtest1.htm

 

In summary their was very little advantage over the stock PAPER filter. An air filter is primarily a filter and should be chosen for it's filtration ability. Many of these performance filters do let more dirt into the engine than a paper filter. You can't offset this with oil changes because this dirt is going directly into the cylinders... not someplace you want ANY dirt. I for one am not going to put something that has oil all over it into my intake up stream from my MAF meter. I have had problems in the past with a K&N fouling my MAF sensor and I am not going to mess with it again. The only advantage a K&N really has over paper is longevity, but with the costly and time consuming cleaning and re-oiling process that is really a wash. You would have to keep a K&N a very long time and/or drive a lot of miles for it to make financial sense.

 

OEM or high quality aftermarket paper for me.

 

thanks for posting the filter test results. i've decided against the K&N filter because the negative factors simply outnumbered the possible positive factors. too many people report the K&N's don't do anything and test results clearly show they don't filter dirt as well as their paper counterparts. i'm sticking with OEM paper filters as i can get them for free once my Subaru Mastercard gift cert. comes in. better safe than sorry, you know.

OK, so if you guys are so against oil filters, who do you recommend? And if you do have a rec, can you verify that they actually make the correct size for the Legacy?

Alright, so you guys got me all stressed about the situation. I went on to KandN's website to find out what the deal is. Here is a link from them with a letter specifically about this case. It's indicating that it's illegal under federal law to void a warranty due to a different air filter. Enjoy!

 

http://knfilters.com/warrantyletter.htm

Alright, so you guys got me all stressed about the situation. I went on to KandN's website to find out what the deal is. Here is a link from them with a letter specifically about this case. It's indicating that it's illegal under federal law to void a warranty due to a different air filter. Enjoy!

 

http://knfilters.com/warrantyletter.htm

 

1st of all, don't be stressed! i wouldn't consider that anything more than a marketing gimmick. i'm reading all kinds of stuff about air filters not because i'm really concerned about the performance of my 2.5i hamster engine but the fact that i'm an engineering student and deeply interested in this kind of stuff. the fact is K&N makes aftermarket filters to MAKE $. common sense tells us that more air flow=poorer filtration. as for oil particles messing up engine sensors, that's highly possible too. the truth is you might get a small amount of HP increase but the amount of dirt your K&N filter lets in can't be too good for your engine either (we're talking about 99.7% efficiency of OEM vs. 97% efficiency of K&N). now the question is will you or most K&N filter owners keep the cars long enough to notice the long-term negative effects? probably not! let's say 1 of every 10,000 K&N customers gets into warranty trouble, it would be profitable for them to cover the financial damage as long as people still buy their stuff.

 

i'd highly recommend sticking with the OEM filters unless you really know what you're putting in your car. don't you think the Subaru engineers spent more time on finding the right filter than the guys at K&N spent on making their filters? i mean you just CAN"T go wrong with the OEM stuff.

The problem arises when people improperly oil their K & N filter. This is done at intervals of 100,000 miles, which you would use 3-4 paper filters in that time. A K & N wire filter is really no different that an intake cone which people use on their engines all the time to gain performance.

 

My best reccomendation. Use the K & N filter for 100,000 miles. You will have gotten your moneys worth of it by not having to replace paper filters and the fuel economy boost will also put more money in your wallet. The sound coming from under your hood might also trick people into thinking you have a short ram intake under there.

I just posted a link that proves that the performance gain is marginal at best, so tell me how it will put money in my wallet? Will it also make me more handsome?

 

K&N filter cleanings are 50,000 miles not 100,000 miles. So it takes longer to get your moneys worth, and I consider my time money.

 

FYI- I had problems with oil gunking up my MAF with the FACTORY applied oil. My mechanic recommended against them. He said that the oiled filters were used for years in motor sports where maintainance issues were not a big deal and then K&N started marketing to the consumer where they cause problems. Seriously, I don't get why people think these things are so great... must be the marketing hype. That free sticker when properly applied in a visible location must be good for at least 3-5 WHP.