K&n Air Filters

[pishta]

Flow through the K&N has never been argued. Hell it's like a screen door, the problem is that it doesn't filter out the fine harmful dust and silica. The website is temporarily down but when it comes back up I'll post the link... but here's one chart & text from it

(the below text is from the test)

"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. See the data tables for a complete summary of these comparisons. "

I have the entire website saved since K&N filters are a common subject in another forum I moderate but the above chart and comments from that ISO test are typical of how the test results turned out.

Again... it's a no-brainer that K&N's have high flow rates but the real issue is that they don't trap and hold much dirt, it passes way more dirt into the engine than any of the other filters tested. Personally I don't race my Lexus (nor do I race my offroad Jeep) so I could care less if it flows more air, I am more interested in keeping harmful dust, dirt, and silica out of my very expensive engines. What I do know is that my personal experience with K&N filters coincides with that of the ISO testing and for a Lexus, I think it'd be short-sighted to want to run a K&N air filter. Our Lexuses were not designed to be high performance cars, at least not in the traditional sense of that phrase, so installing a higher flowing air filter solely to produce better performance just doesn't make sense to me. It certainly won't contribute to better fuel economy, it just doesn't work that way. :)

Interesting, I have another chart that shows that even after the K&N was completely clogged, it still was 50% better than a new paper filter in flow. Granted that these tests were out of a high performance book that is geared toward "more in--more out" theory, It is just a matter of how you manipulate the data. Any good surveyor can gleen the sought after data, no matter who he asks, or how they answer. So it comes down to flow vs. efficiency. Most of us drive on paved roads anyway. The author was convinced the K&N was the superior air filter for HIS applications. Question: what was the "restriction limit" on the filters? Was it a pressure drop test or ? Reason asked is that the paper elements typically have a 1 stage filter, it is a paper element that has microscopic holes in it, once plugged, they are done. The K&N has a much deeper 3 stage filtering process, cotton media, oil, and electro-static. so it takes much longer to clog down to a paper element flow rate.

[lexusnutt]

Flow through the K&N has never been argued. Hell it's like a screen door, the problem is that it doesn't filter out the fine harmful dust and silica. The website is temporarily down but when it comes back up I'll post the link... but here's one chart & text from it

(the below text is from the test)

"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. See the data tables for a complete summary of these comparisons. "

I have the entire website saved since K&N filters are a common subject in another forum I moderate but the above chart and comments from that ISO test are typical of how the test results turned out.

Again... it's a no-brainer that K&N's have high flow rates but the real issue is that they don't trap and hold much dirt, it passes way more dirt into the engine than any of the other filters tested. Personally I don't race my Lexus (nor do I race my offroad Jeep) so I could care less if it flows more air, I am more interested in keeping harmful dust, dirt, and silica out of my very expensive engines. What I do know is that my personal experience with K&N filters coincides with that of the ISO testing and for a Lexus, I think it'd be short-sighted to want to run a K&N air filter. Our Lexuses were not designed to be high performance cars, at least not in the traditional sense of that phrase, so installing a higher flowing air filter solely to produce better performance just doesn't make sense to me. It certainly won't contribute to better fuel economy, it just doesn't work that way. :)

Where do I get an AC Delco???

[IS400]

The fed government has tested the K&N filter for increasing milage and it found no cost benefit for installing one. In essence they said it was a marketing ploy and not really doing much for you based on how expensive they are.

That combined with the sensistivity of re oiling and maybe missing a patch that lets fine dirt in, makes me wonder if they would be more damaging than anything. Air always finds the least resistance area when it flows. That is the area with the least oil and the least filtering ability. Sound logical?

[Jerry Bransford]

Flow through the K&N has never been argued. Hell it's like a screen door, the problem is that it doesn't filter out the fine harmful dust and silica. The website is temporarily down but when it comes back up I'll post the link... but here's one chart & text from it

(the below text is from the test)

"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. See the data tables for a complete summary of these comparisons. "

I have the entire website saved since K&N filters are a common subject in another forum I moderate but the above chart and comments from that ISO test are typical of how the test results turned out.

Again... it's a no-brainer that K&N's have high flow rates but the real issue is that they don't trap and hold much dirt, it passes way more dirt into the engine than any of the other filters tested. Personally I don't race my Lexus (nor do I race my offroad Jeep) so I could care less if it flows more air, I am more interested in keeping harmful dust, dirt, and silica out of my very expensive engines. What I do know is that my personal experience with K&N filters coincides with that of the ISO testing and for a Lexus, I think it'd be short-sighted to want to run a K&N air filter. Our Lexuses were not designed to be high performance cars, at least not in the traditional sense of that phrase, so installing a higher flowing air filter solely to produce better performance just doesn't make sense to me. It certainly won't contribute to better fuel economy, it just doesn't work that way. :)

Interesting, I have another chart that shows that even after the K&N was completely clogged, it still was 50% better than a new paper filter in flow. Granted that these tests were out of a high performance book that is geared toward "more in--more out" theory, It is just a matter of how you manipulate the data. Any good surveyor can gleen the sought after data, no matter who he asks, or how they answer. So it comes down to flow vs. efficiency. Most of us drive on paved roads anyway. The author was convinced the K&N was the superior air filter for HIS applications. Question: what was the "restriction limit" on the filters? Was it a pressure drop test or ? Reason asked is that the paper elements typically have a 1 stage filter, it is a paper element that has microscopic holes in it, once plugged, they are done. The K&N has a much deeper 3 stage filtering process, cotton media, oil, and electro-static. so it takes much longer to clog down to a paper element flow rate.

Once again, NO ONE has argued that the K&N is capable of flowing more air through its screen door-like coarse filter design. Sheesh. The WHOLE point was how crappy it works as an air filter... read the ISO test results, the K&N passed 18X the dirt than the AC-Delco filter did. Remember what an air filter is supposed to do? Filter the air? The K&N lets in way more dirt, I don't know why anyone would continue to remain hung up on air flow. Besides, our Lexus engines seem to run just fine on the paper element air filters Lexus installed at the factory, which is the same type of filter made by AC-Delco, Wix, Purolator, etc.

I can only see young street racers who only focus their thoughts on air flow, which shouldn't be an issue for most Lexus owners... especially since a good quality air filter like an AC-Delco paper element air filter flows very well anyway due to its large surface area.

It's amazing how K&N's hype is swallowed hook, line, and sinker by some... no matter how they drive their vehicles.

By the way, here's a photo of my old K&N air filter and the two layers of pre-filters I had to install over it to keep the grime out of the inside of my air intake. The first layer being a K&N Outerwears prefilter, the outer filter being an oiled foam Unifilter. This is now out of my vehicle sitting on a garage shelf as a reminder of just how bad of a filter I found the K&N to be.

I was amazed at how much grime and dirt my properly serviced K&N air filter passed into the air intake until getting those two layers of prefilters on top of it. I certainly wouldn't have gone to the trouble of ordering the K&N Outerwears prefilter if I hadn't noticed significant amounts of grime & fine silica being passed by the K&N. Then when I found the Outerwears didn't fit tightly enough to prevent dust & silica from getting in from the side and around the Outerwears, that's when I added the foam Unifilter to hold the Outerwears down against the K&N to keep dirt from gettting around it. And even with all that on top of the K&N, wouldn't you know it that I noticed no difference in my engine performance!

The K&N has been proven by the ISO (a scientific organization... International Standards Organization) tests to be a terrible air filter... sure it passes a lot of air but it's the other stuff it also passes that is the problem.

And don't forget that if one filter has 96% effficiency and another has 98% efficiency, the one with 96% efficiency passes twice as much dirt. :)

[lexusnutt]

I agree wholeheartedly. I had one on my F-150 and noticed that after 3000 miles, the oil was filthy (only 10k on it). After switching back, no problems. I can only imagine the damage I've done to it. :cries:

There are a lot of threads on this topic but to summarize, if ANY auto manufacturer thought that a "screen door" filter would add more horsepower w/ better mileage, they would all do it.

Would save them millions of dollars in R&D costs...

[Ezgoin]

I figure after 2+ years of cleaning my oem air filter every 3k miles, it's probably time to just replace it in general. I noticed K&N sells an airfilter for the car that is washable for life, and just sets in place where the oem one sits, no modifications required. Has anyone ever used one of these in their LS? Any horror stories, or effects it would have on the cars super quiet and smooth engine? Not trying to hotrod or anything, just thought the "washable" aspect was pretty cool, and never have to replace it again.

I've read some of the conflicting discussion here, but all I can say is that in the street performance world, K&N is very highly regarded. Personnaly, I run K&N air and oil filters in everything I own, including my LS 430, except my SC-300 which K&N dosen't make an air filter for. I have used Mobil-1 oil and K&N filters in my 95 Chevy truck since it was new, and so far have 177,000 trouble free miles on her.

I built a highly modified Corvette a few years ago and during the break-in of the 383 Stroker motor, I changed the oil about 6 times in the first few hundred miles. I used several different oil filters during that time, and each time I changed one I would cut the old filter open. You would be amazed at the difference in filter quality! Pensoil filters are absolute garbage. Never use a Pensoil filter! Wix was almost as bad as Pensoil! Fram was middle of the road, with reasonable filter material, and decent construction. NAPA Silver was quite good, and NAPA Gold was very well constructed. However, K&N was far and away the best made filter I've seen.

If you properly maintaine a K&N filter, I don't think you will ever regret your decision!

[grandmaster]

K&N let quite a bit of fine dust in. Take your K&N filter out... take a white paper towel and wipe the inside of the air intake (behind the filter where it should be only clean air) and you will be impressed with the amount of dust it lets through. Great for airflow but i'm very leary about how much ultra fine dust it captures.. considering you visibly see holes in the cotton.

[mburnickas]

I used to like the oil glazzed air filters and now I would not use them if someone GAVE them to me for free! They suck and will kill sensors (over oiled) or have high engine wear (too little oil). It is a fine line to get it right and it is far too much work.

If you want use the OEM paper ones, WIX air filter or Amsoil Eaa filters.

[pato]

Hi, Don't use any type of oil type air filter! If you do an oil analysis you will find silica in the oil. This is sand that is getting past the filter. If the filter is less restrictive for better air flow it is not filtering like it should be. I had K & N on my MB 500 S 1995 and my 1972 Pantera and took them off for this reason. Just use a OEM paper filter and change it every 5,000 miles. New member looking to buy a LS 430 2003-2005. Just my two cents.

[AZ Mike]

Relativity is key here. Perhaps a K&N filter does let a LITTLE more particulate through than a paper filter......but as yet I have never seen it proven that it is enough to do any damage to an engine. I have 11 years with a K&N FIPK on my Grand Cherokee......over 100K miles......and no trouble with the engine, sensors, or anything else (FIPK went on in 4th year when it had 70K miles) . I understand the arguments against K&N filters......just haven't seen any science to support them (arguments), and my personal experience refutes them. My own two cents say that the warnings against the use of K&N filters are much ado about nothing. That being said, I don't find any reason to use a filter other than OEM on my Lexus.

I don't know if there is much to be gained in an LS400 that is not particularly restrictive.........but in my Jeep, which has a V-8 fed by a pretty restrictive stock airbox, the FIPK makes a world of difference in throttle response.

[amcdonal86]

K&N let quite a bit of fine dust in. Take your K&N filter out... take a white paper towel and wipe the inside of the air intake (behind the filter where it should be only clean air) and you will be impressed with the amount of dust it lets through. Great for airflow but i'm very leary about how much ultra fine dust it captures.. considering you visibly see holes in the cotton.

For this reason, I would never recommend K&N air filters to ANYBODY. They let so much dust in, and any "increase" in power you get is a placebo at best. I drove around in a 2005 Honda Accord V6 in high school and I changed out the air filter with a K&N. I thought it felt much faster, but then after several months, I changed it back and didn't really notice a difference. You might notice a slight change in sound, but definitely not performance.

If you must use one, make sure that when you clean it and oil it, you do not use too much oil. I have heard horror stories (whether they are substantiated or not is beyond me) about people putting too much oil on those things and having the oil foul up the oxygen sensors.

[jcrome04]

They really suck...

big time.

I had one in my LS. Let in a helluva lot of dust. I'll never own a K&N again in my life.

I would only buy an Amsoil EaA air filter for my vehicle. (for performance) Or WIX for stock replacement. They seem to be the only reasonable alternative to stock.

[AZ Mike]

For this reason, I would never recommend K&N air filters to ANYBODY. They let so much dust in, and any "increase" in power you get is a placebo at best. I drove around in a 2005 Honda Accord V6 in high school and I changed out the air filter with a K&N. I thought it felt much faster, but then after several months, I changed it back and didn't really notice a difference. You might notice a slight change in sound, but definitely not performance.

If you must use one, make sure that when you clean it and oil it, you do not use too much oil. I have heard horror stories (whether they are substantiated or not is beyond me) about people putting too much oil on those things and having the oil foul up the oxygen sensors.

The "increase" in power that you speak of......and don't forget much improved throttle response......will vary greatly depending upon the vehicle. My '94 Grand Cherokee with a 5.0 V-8 came stock with a highly restrictive air box. Replacing it with a K&N FIPK and putting a more free flowing muffler on make a substantial amount of power and a tremendous improvement in throttle response as compared to stock (i.e., measurable hp improvement that can be seen on a dyno......no placebo effect). As I mentioned before, the rig has 175K miles, 100K of that with the K&N, and no engine damage, no sensor damage, or any of the other things that the anti k&n people tell you will absolutely happen if you use a k&n air filter on your vehicle.

Of course, any benefit depends upon how the vehicle comes from the factory. As I said, my Grand Cherokee had a very restrictive air box and muffler on a 5 liter V-8.......so substantial gains can be had from bolt-ons for that vehicle. I also have a Honda S-2000 that was hand built in Japan and so well tuned out of the factory that anything short of the addition of forced induction gives essentially no improvement. I would assume that the Lexus is much closer to the S2000 out of the factory than it is to the Jeep. Besides, I am perfectly happy with the power and throttle response in the Lexus, so see no need to look at making any changes. I stick with the Lexus OEM air filter on the LS400.

If you don't like k&n, that's fine; don't use them. You may or may not see any measurable improvement in hp and throttle response with the use of a k&N depending upon the vehicle. I do have to raise the "BS" flag when people claim that the use of a k&n air filter will lead to the destruction of your engine, greenhouse gas emissions, global warming, higher cholesterol, the federal deficit and whatever else people are blaming k&n for. ;)

[amcdonal86]

For this reason, I would never recommend K&N air filters to ANYBODY. They let so much dust in, and any "increase" in power you get is a placebo at best. I drove around in a 2005 Honda Accord V6 in high school and I changed out the air filter with a K&N. I thought it felt much faster, but then after several months, I changed it back and didn't really notice a difference. You might notice a slight change in sound, but definitely not performance.

If you must use one, make sure that when you clean it and oil it, you do not use too much oil. I have heard horror stories (whether they are substantiated or not is beyond me) about people putting too much oil on those things and having the oil foul up the oxygen sensors.

If you are talking about removing the stock airbox, sure it will make a difference. But then so would a paper filter in that same configuration.

I'm talking about people who literally change their paper air filter with a K&N brand air filter in the stock air box. It makes absolutely no difference (except more dust).

[flop170]

have any of you actually read the stuff on k&ns website.... they guarantee total engine protection....

from their website... "We perform tests of filters both in the factory air box and in SAE/ISO recommended test housing fixtures. Our goal is to design filters with the maximum possible airflow achievable while providing guaranteed engine protection. Our actual air filters when tested generally demonstrate a cumulative filtration efficiency of between 96% and 99%. All this testing we do allows us to guarantee our air filters provide all the protection your vehicle will ever need."

argue it if you want... but they have been making these filters since 1969 and they're still in business and still guaranteeing their products...

[flop170]

hey randy i posted this on the other thread with the same topic..... either like them or hate them.... the end.

[eatingupblacktop]

hey randy i posted this on the other thread with the same topic..... either like them or hate them.... the end.

Geezz.. flop... I think we've got this subject covered!!

Although... I don't think this will be the "end". :D

Maybe it's just the "END OF THE BEGINNING" :whistles: