K & N Air Filters...Do they really make a difference?

[Hand's End]

Or just and excuse to spend more money on the Jeep....

[oddfire]

I put a K&N on my Cherokee and like it, not because of any noticible power increase, but because when it gets dirty you just spray it down and hose it off. I've had it on for about 5 years now and cleaned it probly 20 times, its still in great shape. Definatly a good investment if you wheel in dusty areas..........................phil

[Buggzz]

Originally posted by Hand's End:
Or just and excuse to spend more money on the Jeep....Both,

One of the few performance parts that you can actually feel a difference. I am usually really skeptical about these things. but throw in the reusability of a K&N and you really can't loose.

[SpruceMoose]

i like mine, but i didnt just buy the stock replacement. go here:

http://www.fsjworld.com/mygallery.ten?id=3294&album=6522

to see what i did.

sm.

[AMX factor]

I agree, not a real noticeable difference in performance but figure it costs you $5 every time you change it. I roughly go thru 2 a month that's $10 a month, $120 a year. The $50 filter has already paid for itself.

[Joe Guilbeau]

Take some White Lithium spray grease and spray the inside surface areas of where the the K&N Filters protect, for those of you who have them.

The results might suprise you.

Run the vehicle for about a week and inspect the results, you are looking for grit, dust, the usual suspects that make it past the K&N's, when properly oiled.

For those that haven't oiled in a while, you are in for a suprise.

I tried this on my Jeep and was enlightened.

[710 Burner]

According to flow test data that is somewhat old, K&N has the highest flow rate while capturing the same amount of dirt as the leading paper filter (when properly oiled) Motorcraft was No. 2, AC No. 3, Wix No.4, Fram is just bad.

[andy d]

uhhmn, the study i saw backs up Joe G. think about it it, how could a filter that has the same surface area as another filter, have a higher flow rate while capturing the same size particle? answer , they dont. kn doesnt filter as small a particle as a paper filter. it cant and flow more cfm. as for the cones that hang in the engine bay instead of the hoky looking stock fresh air intake.....no way youre gonna get better performance out of that setup pulling in hot lean air, instead of cooler denser air.

[89grand]

Originally posted by AMX factor:
I agree, not a real noticeable difference in performance but figure it costs you $5 every time you change it. I roughly go thru 2 a month that's $10 a month, $120 a year. The $50 filter has already paid for itself.Whoa, you change your air filter twice a month? That's either over kill or you live in a dusty assed region. I change mine like twice a year.

[Sitting Bull]

I had one for a while - till the INDPENDANT study came out on what particles each catch. No noticable gain on performance for me either - so I don't use it anymore. For no more often than I have to change my filter (once or twice a year), it wasn't worth it to me.

[Panoscopic]

I think they make a difference - in people's minds. I run one on my TJ. If there is a really difference in performance, it would be so small that you could not tell.

[ January 18, 2004, 07:57 AM: Message edited by: Panoscopic ]

[woodybeone]

I have them and agree they have paid for themselves already.

[gwinn]

Originally posted by 89grand:
</font><blockquote>quote:</font><hr />Originally posted by AMX factor:
I agree, not a real noticeable difference in performance but figure it costs you $5 every time you change it. I roughly go thru 2 a month that's $10 a month, $120 a year. The $50 filter has already paid for itself.Whoa, you change your air filter twice a month? That's either over kill or you live in a dusty assed region. I change mine like twice a year.</font>[/QUOTE]I used to change my filter once a month, but I used cheap filters. A better quality filter would have gotten dirty faster.
Now I wash my K&N twice a month and sometimes that isn't enough. The K&N removes a smaller micron size of particulate out of the intake air. Thus it removes more total particulates out of the same volume of air than a paper filter. On the AZ FSJ'er trailride last November I washed my K&N before the trip as well as after. That was a dirty one though. I'm gonna' start buying the K&N oil by the gallon though.
Yeah, it's a darn good excuse to spend more money on the Jeep! smile.gif

[fulsizjeep]

Not so sure I noticed any change in performance, but cleaning the filter instead of buying new ones has saved $$ here in the long run. We have one in both daily drivers.

[andy d]

uhhmn, thats not what i read Gwinn, the k-n Doesnt trap as small a particle as the paper filters, thats why they flow more cfm.

[Joe Guilbeau]

Originally posted by andy d:
uhhmn, thats not what i read Gwinn, the k-n Doesnt trap as small a particle as the paper filters, thats why they flow more cfm.To fix this problem always keep her oiled, and use the stupid looking "Foam Wrap" to cure.

I really suggest that instead of guessing (I spent some time in Oracle Arizona and the back side of Mount Lemon) try the White Lithium Grease on the surface areas inside the filter.

Run her in some dusty environments and after the trail ride, take the K&N filter off. If the filter is no longer RED with oil, there will be dust and grit embedded in the Lithium Whits sprayed surface parts of the Carb or Throttle Body.

If it has fresh oil, then the particles are reduced greatly, but NOT totally.

Which only means that the engine is eating dust and other particles that make it past.

Putting on the Foam Sleeve takes care of almost all of this extra stuff.

[Poley]

I `used to run one in my '93 Explorer and it made a differance in fuel mileage and slight in horsepower. But in a Grand Wagoneer i don't think it would make that much difference. but being able to clean it is nice.

[Alzamon]

I noticed a big difference on my '69 Chevelle with a small block 400 in it. Just more free flowing and it was a noticable gain, especially at wide open when its screaming down the road.

[blt2krl]

Originally posted by Joe Guilbeau:
Take some White Lithium spray grease and spray the inside surface areas of where the the K&N Filters protect, for those of you who have them.

The results might suprise you.

Run the vehicle for about a week and inspect the results, you are looking for grit, dust, the usual suspects that make it past the K&N's, when properly oiled.

For those that haven't oiled in a while, you are in for a suprise.

I tried this on my Jeep and was enlightened.I agree, they flow great filter like crap..

[BIGYELLOW78J10]

The K&N's filter bettr dirty, once they buildup some dirt to pretend to be filter surface area. They still flow more air dirty than a paper filter, but do let fine particles through.

I doubt my J-10 would care if it sucked in dust as fine as flour, but my Toyota doesn't care for the K&N. Actually, the truck liked it fine, a little more oomph of the line, and that nice intake sucking noise give a perception of power, but replacing a $130 IAT/MAF sensor made me think otherwise.

I think I will be trying an Amsoil foam filter in the near future. We'll see.

They fine particles that get through may be just what you need to block up those oil leaks in your engines:d

Daniel

[Rich 89 Gr. Wag]

I've read that they let in particles that a paper filter would catch. So, basically solid particles enter your combustion chamber and slowly cause damage as the piston rings drag the sand and silica particles through your cylinder walls. Over time, it adds up and reduces the life of your block.

[Serious Johnson]

I've used K&N air filters for about 25 years now, on some motors that have gone a quarter-million miles so equipped. Hell, there's one on my daily driver/weekend racer downstairs, and I don't recall having even cleaned it in the last ten years!

Daniel:

The MAF failure that you describe is commonly caused by over saturating (sort of a doubled-up term) the filter media so that free oil coats the components.

Thing about K&N filters is that, the more you leave them alone, the better they perform. They're not for those who want a big woosh of instant gratification. Maybe they could broaden their market by offering a swooshy HP enhancing sticker.

:-

[mattmulchi]

So if you put on the foam sleeve thing though, it should protect about the same as any restricting paper filter right? You would then still be able to clean and re-oil the actual k&n filter when you would have to throw away other paper filters. The real question I guess is, would the addition of the foam sleeve protect as well as paper, and if so I hope the foam sleeve is available in our sizes. I currently have a k&n with mud spray on the outside, that is in bad need of cleaning.

[millertime]

Well ok they flow more with the same s/a. But their is other differences between how the k&n filters compared to paper elements. K&n is oiled and the oiled element filters. @ different filtering systems. Does anybody have links to the independent studies?

[popeye44]

I used to change oil on a couple ranch trucks for a rancher. We talked him into getting a K&N after he probably spent 150.00 in air filters. every time he came in we'd change one and it'd be packed solid with dirt etc. The truck we put the k&n in had 100K on it and was a ford diesel with a banks turbo. when I left there 5 years later he was still using that truck and had purchased a second filter for us to keep oiled and ready for him when he came in. That same truck had 400K on it. I'm sold on them.. Keep em oiled and even when dirty they allow air past. I never noticed any debris or dirt inside his air housing and with as many miles as he'd put on those "large?" particles of debris should have had some affect. The old oil housing filters were the best but in a 4x4 environment they obviously no worky too good hehe. On the other hand.. we used to have another fella that was a road vet "cows and dairies around here require lots of vets" He used one gallon delo 400 and one gallon recyled every oil change and always used a re-cleaned air filter and last I seen of him he was 400K plus on his cummins.. :D

I've seen 3 cyl cars with 340K on their original motor but I also changed oil in that car every 3 weeks "rural mail car" I think K&N is fine and would never hesitate to use one.. What you save in the long term can be used to pay the labor of taking care of the filter :D

[nograin]

Take a look at David Vizzard's books such as How to build hp vol. 2. or Fischer & Urich's book on Holley carbs for three good independent studies.

In most instances, airflow to engine will not change for any given condition. What will change is the pressure drop across the filter. This may produce a slight increase in efficiency and also may slightly effect the fuel air mixture in certain circuits. If you are running a vacuum secondary carb, it will effect opening of the secondaries.
If you are running a 4 bbl carb on an v-8 engine with peak horsepower above 4500 rpm, then the better flow will measurably help performance.
The other point though is significant. The K&N will let you run longer in dirty, dusty off road or competition conditions than a paper element.
The filter area is of an oiled cloth element is not comparable to the surface area of a paper element. However, your point about surface area is valid for similar materials wth similar mesh or opening areas. Not all brands have the same surface area because they material gan be accordianed more or less. The studies in the Vizzard book show the Motorcraft to be one of the best paper elements they tested.