K&N Air Filters - Better or Worse

Mark20

Original poster
Member
Dec 6, 2011
1,630
Not too long ago I read a comment on another forum that K&N filter worse than standard filters. Can anybody clear this up?
 

Boricua SS

Member
Nov 20, 2011
3,080
Ohio
i too read something along the lines of them attracting and/or retaining more dirt then other filters... im sure others will chime in...
 

Busterbrown

Member
Dec 4, 2011
253
For breathability, K&N air filters can't be beat. I purchased my first for my Rainier over the past summer and the filter still looks remarkable clean. I've read 20K between cleanings is all that's required. I've also read posts of long time K&N owners who have run 100's of 1000's of miles on the same filter. For dryer, smoggier climates, oiled filters may not be the most suitable choice. I think those aggressively running offroad would detest the K&N's.
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
Mark20 said:
Not too long ago I read a comment on another forum that K&N filter worse than standard filters. Can anybody clear this up?

I read that too.

The OEM filters, filter out more and smaller dust particles.
 

Regulator

Member
Nov 20, 2011
2,496
Better breathability means a more porous filter, which means more potential for dirt to pass through the filter. Keeping the filter properly oiled is supposed to help prevent this.

I am running a K & N on my Bravada, which is lowered and never sees a dirt road. I love the sound, and think I feel a slight performance boost. I clean and oil the filter every oil change (8k-10k miles) just to be on the safe side. I would not even consider running it on my Envoy though as it sees a lot of dirty and dusty air.
 

DJones

Member
Jan 21, 2012
701
St. Petersburg, Florida
What I don't understand is why the filters aren't listed in terms of microns and surface area. Then, as long as the biggest size passed through the filter is smaller than the maximum size of dirt that could be damaging to the engine, we should be fine. A filter with more pleats has more surface area, and therefore more breathability, regardless of particulate size.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Busterbrown said:
For breathability, K&N air filters can't be beat.
Yes they can. I have played with a flow tester and seen how a Green Air Filter flows better than a KN. I also saw that there is virtually no difference in a stock vs K&N flow. Some parts stores and many truck shows with have testers that you cant change any variable but the filter so you can see the effects.


Busterbrown said:
I purchased my first for my Rainier over the past summer and the filter still looks remarkable clean. I've read 20K between cleanings is all that's required. I've also read posts of long time K&N owners who have run 100's of 1000's of miles on the same filter. For dryer, smoggier climates, oiled filters may not be the most suitable choice. I think those aggressively running offroad would detest the K&N's.

I do detest K&N. I ran them on multiple vehicle and equipment but never will again. Look at the inside of a K&N and you see dirt...dirt that has pulled through and you dont see the dirt that has passed through completely and is junking up your motor. There are lots of tests out there showing that K&N filters allow more particles through. Your filter may look clean because you are n a clean enviroment or because the stuff that should have been trapped by the filter went through...

If you want a great filter that actually filters and keeps out dirt and flows excellently, check out Green Air Filters.

http://gmtnation.com/f25/green-filter-experience-158/

The pictures speak for themselves.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Busterbrown said:
...K&N air filters ... still looks remarkable clean. ...
That's enough of a clue there for me, and part of why I took mine off ans discarded it instead of selling it. I want a filter to look dirty. Means it's working. Not to the point of getting clogged, but dirty is good.
 

Mark20

Original poster
Member
Dec 6, 2011
1,630
I also found the Duramax comparison. The K&N will be coming out of the Silverado this weekend. I just installed it last weekend but haven't driven it much.

Who would have thoought GM would have the best filtering air filter though that comes at a price in terms of flow restriction.
 

Fire06

Member
Dec 18, 2011
7,223
I have heard that EA filters from AMSOIL are good. I am presently trying one in the truck but has not been long enough to notice anything. The k&n filter I had in my car (ford) messed up the mass air flow sensor over time due to the oiling of it. Cleaned it a few times but ended up replacing the sensor
 

Mark20

Original poster
Member
Dec 6, 2011
1,630
Looking at the Duramax link posted above, the Amsoil isn't much better than the K&N.
 

Fire06

Member
Dec 18, 2011
7,223
Mark20 said:
Looking at the Duramax link posted above, the Amsoil isn't much better than the K&N.

Thanks for pointing that out. Not what I expected but glad to know it. This Green filter that is mentioned has any one seen the testing on it??
 

Bartonmd

Member
Nov 20, 2011
545
Mark20 said:
I also found the Duramax comparison. The K&N will be coming out of the Silverado this weekend. I just installed it last weekend but haven't driven it much.

Who would have thoought GM would have the best filtering air filter though that comes at a price in terms of flow restriction.

Not really, for us non-SS guys, especially... The stock filter has plenty of media, and isn't really restrictive at all, to begin with... 99% of the 1-2hp improvement you see from a K&N in these is from the larger diameter, smoother tube...

Mike
 

MDBT

Member
Jan 26, 2012
223
DJones said:
What I don't understand is why the filters aren't listed in terms of microns and surface area. Then, as long as the biggest size passed through the filter is smaller than the maximum size of dirt that could be damaging to the engine, we should be fine. A filter with more pleats has more surface area, and therefore more breathability, regardless of particulate size.

Increased surface area makes for better breathing when you are comparing two filters of the same flow/type. A fibrous filter like the K&N (wet) or Amsoil (dry) flow more air per square inch than your typical paper filter. You will need a larger surface area of paper filter to equal the flow of a standard size fibrous filter. In this case, particle size does matter because bigger holes that let in larger particulates also let in more air.

In the powersports world the guys worried about filtration and water run oiled foam filters while the ones looking for every ounce of power run fibrous ones. Due to the prevalence of water in the terrain run by these vehicles and the shapes of filter typically installed paper is out of the equation. In the last few years a lot of competitors to K&N have come out touting equivalent or superior flow and often without oils. This is basically done by throwing a lot more layers in, I believe the Amsoil has 6 or 8 layers in many applications. The benefits over K&N besides the flow typically include better filtration, less maintenance, and no issues related to oil in the intake. The "green" filter one member is touting is an example of one of those pieces. Amsoil makes them as well, from "nanofiber". Not to be confused with the foam filters that also bear an Amsoil name or the TwinAir two stage foam filters sold under their banner.

The multi-layer fibrous filters are the hot hand and probably the way to go if you want better breathing but are concerned about filtration.
 

PatM

Member
Jan 27, 2012
25
Take the money you would have spent on fancy filters and change your OEM one more often. You'll save money and end up with a longer living engine and pretty well an equal performance over time.

One thing people tend not to think about is that your engine only pulls in as much air as it needs. As long as your filter can handle that there's no such thing as "better" when it comes to airflow.Really, unless you're flooring it at every stoplight or racing at the track you'll see no appreciable difference between filters.

A co-worker of mine decided to run GM60 fiberglass filters on an HVAC system (I do buildings) while I stuck with AP40 pleated filters. He was bragging how his lasted six months while mine went three. After one year the supply and exhaust grills in his building were black and horizontal surfaces were very dusty. In my buildings the grills were white and horizontal surfaces had very little dust. I spent three times as much on filters while his building spent 20 times as much on annual janitorial labour and supplies.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
PatM said:
Take the money you would have spent on fancy filters and change your OEM one more often. You'll save money and end up with a longer living engine and pretty well an equal performance over time.

My "fancy" filter cost me about $60 when I got it nearly three years ago. With normal use I would have replaced it about 5 or 6 times. With my offroad performance use I have packed it with mud or gotten it wet another 4-5 times. So at $15 a piece for OEM filters, I would have spent almost $150. Not sure how that saves me money... Even without my extra offroad activity and needs, the "fancy" filter still allows you to come out ahead cost wise.


PatM said:
One thing people tend not to think about is that your engine only pulls in as much air as it needs. As long as your filter can handle that there's no such thing as "better" when it comes to airflow.Really, unless you're flooring it at every stoplight or racing at the track you'll see no appreciable difference between filters.

I can agree. As long as your filter can meet the maximum demands of your vehicle, it is adequate. That being said, my stock exhaust worked to. It only expells as much as the engine pushes through it. However with my custom exhaust I seem to have more power and mpg. I would say my free flowing air filter also helps me maintain respectable fuel economy even with large tires and the weight of steel armor. Should people that dont floor it get a smaller filter since their engines do not need to pull in as much air?


PatM said:
A co-worker of mine decided to run GM60 fiberglass filters on an HVAC system (I do buildings) while I stuck with AP40 pleated filters. He was bragging how his lasted six months while mine went three. After one year the supply and exhaust grills in his building were black and horizontal surfaces were very dusty. In my buildings the grills were white and horizontal surfaces had very little dust. I spent three times as much on filters while his building spent 20 times as much on annual janitorial labour and supplies.

My labor is free to my truck and I am happy to do it. I actually do have more labor in my washable filter since I tend to clean it more often than I would change a typical filter. So my engine actually gets cleaner air more of the time. It is cleaned about every 5,000 miles and I usually change an air filter about every 10,000 miles in all my vehicles due my area and conditions.
 

Bartonmd

Member
Nov 20, 2011
545
FWIW, the AC Delco filter is $30 for this (others are $25, because it's a round filter), and the FSM says change every 50k miles... That's if you don't get it wet...

I probably won't, but I would get a green filter, if I was going to get one... The material, itself, likely doesn't flow as well as the "screen door" K&N, but like the stock one, it's got more pleats and more surface area than the K&N, so the filter as a whole flows as well and filters better... Not to mention being cloth, instead of gauze, it doesn't like to let mud and things through, when mechanically pushed on... I've seen it in person, and Kyle's clean intake and inside of the filter are enough for me, after what he's put it through...

Mike
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
I will admit I took a chance of the Green brand since I never knew anyone to use them, but I am glad I did. I just hope that in sharing my experience it may help others.
 

DocBrown

Member
Dec 8, 2011
501
HARDTRAILZ said:
There are lots of tests out there showing that K&N filters allow more particles through.

I have yet to see any studies which proved that this filter caused direct engine damage, or that it shortened the life of an engine. Has anyone who used them ran them 100k miles +? I have with no ill effect. I had a '95 'Burb which had one on when I bought it at 97k. The owner said it was on when he bought it at 40k. My dad has the truck now, it still has the same K&N filter with 165k.

We're talking extremely small particles here that will more than likely burn up before they do any damage. Your truck will rust away around you long before the engine dies due to using a K&N filter.

When all is said and done though, I would probably never buy one again. Very little gain for the money, IMHO, unless done in tandem with other performance mods.
 

Bartonmd

Member
Nov 20, 2011
545
DocBrown said:
I have yet to see any studies which proved that this filter caused direct engine damage, or that it shortened the life of an engine. Has anyone who used them ran them 100k miles +? I have with no ill effect. I had a '95 'Burb which had one on when I bought it at 97k. The owner said it was on when he bought it at 40k. My dad has the truck now, it still has the same K&N filter with 165k.

We're talking extremely small particles here that will more than likely burn up before they do any damage. Your truck will rust away around you long before the engine dies due to using a K&N filter.

When all is said and done though, I would probably never buy one again. Very little gain for the money, IMHO, unless done in tandem with other performance mods.

There was an article about a guy who worked at a huge travel pit, and they were trying to use them as pre-filters for their large equipment, but they weren't catching much of the gravel dust, and their main filters were getting plugged, so the gravel company gave up the project and just went back to replacing paper filters. He kept the K&N on his company 1/2 ton 350-powered Chevy, that finally wheezed its last breath at around 80,000 miles, when it finally didn't have enough compression to run at all. I can't find the article, now, but this is the reason that manufacturers put filters on engines, instead of just screens. It does shorten the life of the engine.

Likely burn up before they do any damage?? I don't know about you, but I'm talking about 4-stroke engines. The peak flame temperature in an engine is right around the melting temperature of silica (2000F), so it could be liquified during actual combustion, but there's an intake and a compression stroke in there, between when the silica gets into the chamber, and when it could be melted.

In most of the midwest, it's probably fine, unless you spend a lot of time on gravel. I have a K&N in my street bike, for instance. I did end up doing a bunch of riding on dusty gravel roads on one trip, though, and the UOA said that silica in my oil was enough such that the oil was abrasive to the engine. Good thing I changed it right after I got back home (after 850 miles on the highway, anyway)... If you live in AZ or go to the desert a lot, or spent any time on dusty gravel roads, or off road, I WOULD NOT run one...

Mike
 

SILVOY

Member
Jan 23, 2012
16
I have a CAI 77 series on mine and have no issues..i have wheeled it numerous times in dusty enviroments and dont see dirt down the tube like others claim to say happens..the only issue i would have is the metal tube retains more heat then the plastic making it a HAI..lol if people are worried about gunking up their motors just sea foam it..right? the sound is great with the throttle body spacer with it. no complaints from me..
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
SILVOY said:
with the throttle body spacer with it. no complaints from me..

All credibility gone....
 

Spalding1028

Member
Jan 20, 2012
60
The only practical thing I could think of as far as tb spacer usage goes, is on carbureted applications (my '64 1bbl nova used to like to boil fuel in the carb after shutdown, and spacing it away from the hot intake manifold was one way to alleviate it.)
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Spacers do not work with our motors. Snake oil to empty people pockets of money. If you think it makes a difference than it is difficult to believe anything you said about the filter esp when there is a link to real documented testing....

Bartonmd said:
Read this: ISO 5011 Duramax Air Filter Test Report
ALL OF IT!

Basically, the K&N lets in ~100x as much dirt as the AC Delco, flows a little better for a little bit, then clogs up quicker and flows worse...

Mike

But I do apologize for how I said it. You did not make a big claim promoting the spacer. But you may as well take it off as it adds nothing but weight. You also may want to do something about the HAI since it cant be helping anything. Maybe wrap it like headers... I know I did see more dirt downstream of the air filter with KN than with basically any other filter guess you are luckier than I.
 

Bartonmd

Member
Nov 20, 2011
545
SILVOY said:
lol if people are worried about gunking up their motors just sea foam it..right? ..

The problem isn't "gunking up" the engine with silica (sand). The problem is that it scratches your cylinders, then gets into your oil and makes your oil abrasive to everything it touches (all of your bearings, cam lobes, oil pump, etc.).

Mike
 

SILVOY

Member
Jan 23, 2012
16
Bartonmd said:
The problem isn't "gunking up" the engine with silica (sand). The problem is that it scratches your cylinders, then gets into your oil and makes your oil abrasive to everything it touches (all of your bearings, cam lobes, oil pump, etc.).

Mike

I never said that the tb spacer made a difference with performance..just sounds cool on shift change..ya i get the whole fine partical sand issue and not going to argue about that but wouldnt that take a really long time to take an effect on the motor..take drinking per say..we all do it knowing that later in life our liver will probably have issues but we gamble with it..but when we get that old we dont really care at that point..my thoughts about the k&n CAI..lol..you all make great points though and I will keep that in mind..wrapping the intake is my next project to work on..is there any specific material that I should use?:undecided:
 

Bartonmd

Member
Nov 20, 2011
545
SILVOY said:
I never said that the tb spacer made a difference with performance..just sounds cool on shift change..ya i get the whole fine partical sand issue and not going to argue about that but wouldnt that take a really long time to take an effect on the motor..take drinking per say..we all do it knowing that later in life our liver will probably have issues but we gamble with it..but when we get that old we dont really care at that point..my thoughts about the k&n CAI..lol..you all make great points though and I will keep that in mind..wrapping the intake is my next project to work on..is there any specific material that I should use?:undecided:

I'm not sure the liver is a good example, especially with the Atlas I6 4.2L... Your liver keeps working until it's had enough and quits. An engine with a lot of silica intrusion will have a steady decline in power, with a steady incline in blowby, and a steady loss in oil pressure from the bearing clearances and oil pump clearances getting bigger. With the extra blowby in the Atlas engine, without a PCV valve, it will put more oil into the intake, which will cause you to have to clean your throttle body a lot more. It's not just a light switch thing. It's accelerated wear.

Mike
 

Bartonmd

Member
Nov 20, 2011
545
the roadie said:
What do you mean *we*, youngster? :cool:

View attachment 8450


Pretty much... My Grandpa has never really drank, is about to turn 81, only takes a multi-vitamin daily (no other meds), and can still work me into the ground.

A picture from this weekend, when him, I, and one of our hunters were clearing trails after the recent logging on part of the farm. He's on the right.

482089_4048583467056_428053552_n.jpg


Mike
 

SILVOY

Member
Jan 23, 2012
16
you bring a good point..i should have just left my envoy stock! haha.. is there a better filter that can fit on the end of the k&n? its the filter not the intake that is the killing issue right?
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
SILVOY said:
you bring a good point..i should have just left my envoy stock! haha.. is there a better filter that can fit on the end of the k&n? its the filter not the intake that is the killing issue right?

Right. I believe the stock filter would still fit. :undecided:
 

SILVOY

Member
Jan 23, 2012
16
Wooluf1952 said:
Right. I believe the stock filter would still fit. :undecided:

I tried to put the stock filter on it but the diameter is bigger on the stock filter than the tube..just a food for thought i called k&n (the main source)and asked them about everyones concerns with thier filter that really doesnt filter..they said that they have a "racing filter" which would cause such damage in dusty enviroments cause it is meant for particular vehicles( more like a screen) but that is not the filter they sell with the kits for standard vehicles. They have been around for a long time and never once have they heard of an issue of what you guys are inquiring about..if they sold a product that damaged engines then they would be out of business by now and a crap load of law suites! they run their filters through computer testing before its put out to the public..i see where you guys are coming from and it makes me scratch my head about it but its a "theory" in my opinion..i guess to each is own..
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Did you bother to read the testing in the provided link?

Of course K/N is not going to say anything negative about their own products.
 

Bartonmd

Member
Nov 20, 2011
545
SILVOY said:
I tried to put the stock filter on it but the diameter is bigger on the stock filter than the tube..just a food for thought i called k&n (the main source)and asked them about everyones concerns with thier filter that really doesnt filter..they said that they have a "racing filter" which would cause such damage in dusty enviroments cause it is meant for particular vehicles( more like a screen) but that is not the filter they sell with the kits for standard vehicles. They have been around for a long time and never once have they heard of an issue of what you guys are inquiring about..if they sold a product that damaged engines then they would be out of business by now and a crap load of law suites! they run their filters through computer testing before its put out to the public..i see where you guys are coming from and it makes me scratch my head about it but its a "theory" in my opinion..i guess to each is own..

No, their filters do exactly what they want them to do. They even advertize that their filters are 96% effecient at catching dirt, but they don't tell you that the AC Delco filters are 99.97% effecient, so they let in 100 TIMES the amount of dirt as a stock filter (and only flow a little better from the start, then plug up quickly and flow worse than the stock filter). All it took to have the Blackstone UOA folks tell me that my oil was abbrasive because of the high amount of silica in, with the K&N on my bike, was a ~15 mile dry gravel road following some cars and other bikes. They haven't been sued, because it would cost more to sue them than the life that is removed from a car that has 150k miles on it, instead of the 200-250k miles that it could have lasted, otherwise. They haven't been sued because it won't cause a FAILURE, per se... It will just degrade performance and accelerate wear over time. Hell, the guy who worked in a gravel pit's 350 lasted 80,000 miles of mostly dirt roads, before it didn't have enough compression to run. It's also pretty much imposible to prove in court. They could say that you installed it wrong, or that you didn't oil it right or enough when you cleaned it, or that you probably had a vacuum leak or something else that was letting dirt in.

Back in the day when companies just stuck whatever air filter out of the parts bin on a car and called it good, yeah, maybe you put in a K&N and free up the airflow, and trade the power/mileage for decreased engine life. Now, though, they have to make the stock filters and intakes flow freely per the engine size, so that they get good mileage and make good power, so you don't have the flow issues that you once had, stock. Hell, the SS guys, with 100+ more HP than you have don't even get big gains from going to a K&N, and we all have the same stock filter.

Believing them that "it's fine, these guys don't know what they're talking about" is the same as the proverbial "fox guarding the hen house"... Ask the guy who is selling you something if it's OK to use the product he's selling you.

Mike
 

SILVOY

Member
Jan 23, 2012
16
HARDTRAILZ said:
Did you bother to read the testing in the provided link?

Of course K/N is not going to say anything negative about their own products.

yes i get the fact that they will talk up their product. but wouldn't they be out of business plus have law suites against them? there is not one warning lable about ruining the engine.. btw nice rear bumper! Looks sweet!
 

Bartonmd

Member
Nov 20, 2011
545
SILVOY said:
yes i get the fact that they will talk up their product. but wouldn't they be out of business plus have law suites against them? there is not one warning lable about ruining the engine.. btw nice rear bumper! Looks sweet!

See my post.

And thanks! Lots of time in that one!

Mike
 

benz01

Member
Jun 2, 2012
53
Kansas
After reading some of the input from people on this board and doing some research, I dumped the K&N as fast as I could on both our vehicles. Even the possibility that using them could shorten the life of the motor is more than enough to change my mind no matter how great it makes it sound or how much performance it is supposed to increase. The $ you could save in MPG is no where near the $ is would cost to replace a motor. To me, it's not worth the risk so back to WIX air filters it is.
 

rodehawg

Member
Jul 19, 2012
13
Mark20 said:
Looking at the Duramax link posted above, the Amsoil isn't much better than the K&N.

It doesn't look like the test used an Amsoil EA filter though. All EA filters have EA in the part/model number. The test used something called TS123.
 

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