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K&N bashing

4K views 37 replies 20 participants last post by  NYC F-350 
#1 ·
I've noticed that K&N air cleaners take quite a beating on these forums with statements like 'let too much dirt through' or 'K&N and turbos don't go together'. What's conspicuously absent is any concrete data to support these statements. I'm not necessarily a K&N defender but I'm also not one to jump on the rumor bandwagon. Can anyone cite any concrete data/examples of K&N's failures?
 
#2 · (Edited)
When I was in the atv racing and etc there was some tests that used a white substance and black light and found the k&n let a lot through but I don't remember who done it and I'm not looking it up. It's not really that big a deal if you feel the need to run k&n then do so if not that's fine too. It's your truck

Edit: Thank a phone for auto correct
 
#3 ·
You 'don't remember who done it' and you're 'not liking it up'? That's not very convincing. And by the way, I know my truck is my truck and I'm not looking for anyone's approval to use K&N. I haven't decided between AFE, S&B, and K&N. I'm simply wondering whether all the criticism of K&N is actually justified.
 
#4 ·
Ok ,so he had some type o's.
 
#5 ·
^^damn sassy. no proof or test results or anything, but ive seen diesels suck those things white, thats personally why i wont run them
 
#8 ·
Ok, we got the smartassiness out of our system. According to the ten year old data that 'drunk' referred me to, AFE performed poorly but is very popular among Powerstroke owners. I think I'll stick with the stock air cleaner until it shows that it can't hang with my 250 hp Spartan tune.
 
#10 ·
In my experience with vehicles, the most popular parts are the most popular for good reason. They hold up and they produce the best results. That being said, I know a guy running a K&N on his truck and has no complaints about it. When the time comes for me, I will be doing either the S&B or the No Limits intake.
 
#11 ·
I have not conducted any controlled experiments, but I have 4 90's Mitsubishi-built turbo cars - one 1998 with 17x,000 miles on it, a 95 with ~185k, and another 95 with a little over 199k on it. All have run K+N filters almost all their lives; the 199k car melted an exhaust valve at ~150k, so technically it's not running the original motor - but the bottom end is 100% original. All have good compression and negligible leak-down. None of them have their original turbos, but that's purely for power/efficiency reasons, nothing else.

The fourth one is used exclusively for autocross and that one's gone through more motors and turbos than I can keep count of :)
 
#12 ·
So many people run K&N because they spent the most money on TV advertising for so many years. Its called a sales pitch and people bite off on it. From other stuff I read though supposedly K&N has made their conical filters much better.

Their filters claimed more mpgs because they let more are in. The only way to do so is to make them less restricted. Thats also why they use oil. As the dirt passes through, it may touch and stick to the oil, instead of passing through if you didn't oil the filter.
 
#13 · (Edited)
Did anyone else get the impression that the OP already had his impression of K&N set in stone and was just trying to get someone to change his mind even though it cant be changed?

Maybe most of us just don't like K&N because it has two letters instead of three like AFE.

You can type in something about K&N filters on google and you will come across a forum that bleeds K&N and the next one you come across everyone may be against K&N. Its easier to see the negative in something rather than the positive because when everything is going positive you are always wonder if it will ever have a negative. And "ever" is a long time. If something negative happens then it is already proven. See what I am saying? All it took was that one test that I followed closely to see what K&N filters let through. It was done by someone with no affiliation to any company, I think the guy may have had some ring problems a couple times ore etc in order for him to finally decide to conduct a test to figure why.
 
#14 ·
Did anyone else get the impression that the OP already had his impression of K&N set in stone and was just trying to get someone to change his mind even though it cant be changed?
:rofl: now thats funny and I agree....

to much oil + turbo = bad...
to little oil + turbo = dusted turbo

why not run a "dry" filter and not have to worry about it? :dunno:...thats why I dont run a K&n on anything turbo, but I run one on wife's envoy and my ranger because they're a good filter just not for turbo, I can provide data and info but google can to soooo go here and find for youself link
 
#16 ·
Let me add guys the old K&N was 4 layers and the new one is 6 layers.

If the installer does a bad job and leaks. Well I think you know.

I have K&N and it has done great but if I had to do it again I would of probably bought a No Limits as it has the "Air filter change" indictator removed and a hugh filter.
 
#18 ·
It has the Air filter indicator (which you would probably never suck in), just doesn't have the hole for CCV
 
#20 ·
FYI No Limits uses an aFe filter (mine was the 5r)...the advantage of the No Limits is that the filter is about twice as big as the one on my aFe StII. Like Woodboy said, you won't have to worry about sucking in the filter minder with it.
 
#21 ·
It's not that my mind can't be changed, I'm just having trouble figuring out how they were able to become so successful if they're selling a bad product. Usually that catches up to you pretty quickly. I sent K&N an email asking what they could provide to convince us that their air cleaners are safe for our trucks. I'll share their reply if I get one. I suppose I do have some bias in that I've had a K&N on my 7.3 for years without a problem. It's when I got a 6.4 and started researching air cleaners for it that I started to wonder if the criticism of K&N was justified.
 
#22 ·
For the sake of arguement lets say the "new" filters do a lot better job filtering and that is what was on your 7.3 that did so good, that still doesn't mean it is a good choice for the 6.4. The 6.4 moves a good bit more air than the 7.3 (without significant mods). You would need to know the surface area for the filters on both the 6.4 and 7.3 filters, but if they are close, the 6.4 will be pulling more/creating more vacuum than the 7.3. That effects filtration so the K&N may have been adequate for the 7.3 and still not be good enough for the 6.4.
 
#24 · (Edited)
My email to K&N and their response:
Hello,
I own a 2008 Ford F250 Super Duty with the 6.4l Powerstroke and I’m a regular visitor to a couple of Ford Powerstroke owners forums. I’ve noticed that KN takes quite a beating on these forums. Is there some data that you can show me that would convince me that KN air filters are safe for our trucks?

Hello,

Thank you for your interest in K&N products. One of the largest areas I personally see on the forums is that our filters flow more air so they must let too much dust through, that claim is false and normally when you ask someone claiming this to show you a test that proves it, they can’t produce the test, or they quote some obsolete test that has nothing to do with your specific air filter.

Here is some information to help you. K&N performs multiple tests to verify that air filters will not only perform as expected however will also still protect your engine. In this case, (and here is the data/test results) we offer the E-0785 air filter for your truck. This filter, when tested in our lab, had an initial efficiency of 99.22%, an overall efficiency of 99.63% and held a total of 538.2 grams of dirt before it was plugged and needed to be cleaned.

You can find that test result here: http://www.knfilters.com/dynocharts/E-0785.pdf

There is a lot of mis-information and false claims that are out there, I recommend always asking for test results when someone makes a claim about any product and what it can or cannot do, that way you can compare the two and know which you would prefer.

If there is any more information or questions that you have, please feel free to contact me directly.

Thank you for choosing K&N Engineering

James Johnston
K&N Engineering Inc
K&N Performance Air Filters, Air Intakes, & Oil Filters
Phone: (800) 858-3333
 
#29 ·
Unfortunately, this test tells me nothing about whether the K&N will be adequate for my truck. The test specifically said, "Keep in mind, this test protocol was not developed or intended to identify how an air filter will perform in a vehicle during operation". Don't misunderstand what I am trying to say, I DONT know if the K&N is a good choice for a 6.4. Based on previous results comparing other filters, they didn't do as well. Maybe they have improved and the results today if performed by a non-biased 3rd party would test them would be different. As was discussed in this test, the pressure at which air is flowing will affect the filtration ability (as it would on any filter). My truck is flowing about 600HP with of air and that is about to go up so in general, the larger the surface area of the filter, the less pressure there will be to at any once place on the filter. My No Limits CAI filter is massive in size. That means that even if the filter on my No Limits was inferior to K&N (or any other brand), it still may provide better filtration. When I consider that my No Limits filter is the same material as the aFe St II 5r (just much bigger) and I have never heard of anyone developing a problem related to filter filtration to the 5r on an aFe St II (and there are a sh#tload of people running that setup), I feel comfortable that I am getting adequate filtration for my application. I am not saying that the K&N may not be adequate for your truck, but the fact is we don't know and I doubt we will ever know for sure because it unlikely anyone will ever perform such a test. That makes me lean towards spending the extra coin on the No Limits and never worrying about it. In the end, each of us gets to decide if we think think whichever brand filter is adequate for our needs and it is somewhat of a guess since there is no hard data one way or the other....in that case, I prefer to look at how many people have used such and such setup and see what their real world results are.
 
#28 ·
My aFe is oiled too.
 
#30 ·
K&N is fine for an engine, bad for turbo impellers. It's just common sense.

They let very fine particles through that mostly find their way through an engine without doing damage to cylinders and rings but those fine particles flying through the turbo wheel at high speed will wear it down over time. It takes a really long time for it to happen and it depends on what kind of particles are in the air where you live. Some that live in an area with a high level of ash (mt st helens wa) eat up engines much faster with even the best filters. People living in area with rain year round will show no signs of wear due to dust particles.

Air filters are almost optional most of the year where I live.
 
#31 ·
S&B also tests to the internationally accepted ISO 5011 Standard when testing for airflow, efficiency and capacity. This is the same protocol used by most of the large automakers. Although I can't find it on their website, I would imagine AFE uses the same test.
 
#33 ·
I know it's not a scientific test but I replaced my OEM filter at 5000 miles with a K&N filter, after 55000 miles I pulled the K&N and it still wasn't as dirty as the OEM was at 5000 miles and that was good enough reason for me to not use K&N filters again.

Results may vary.
 
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#34 ·
Yeah I put a K&N on my 03 f150 w the 5.4 and ran it for about 20000 miles. After taking it off I looked down into the intake tube and could take my finger and rub and see the mark left by my finger in the very fine dust. Maybe that dust wasnt bad enough to harm my engine but I never saw that with oem filters before or since. So with that being my own "test" results I would never think of a filter like that to protect an engine as high dollar as these 6.4's. I'm not trying to bash their product really, I just dont think they are good for daily drivers where thousands upon thousands of miles is the goal.
 
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