K&N air filters.....Good or bad?

[1992tractor]

Talking with a buddy (diesel mechanic) tonight about needing to pick up some air filter cleaner to clean my K&N air filter, he mentioned that I shoudl throw my K&N out and go back to paper filters. He mentioned how they let too much dirt through the large holes in order to get more air flow which in turn can be detremental to the my engines health.
What are your guys opinions? Do any of you guys run a K&N?
Should I change, if so to what brand? If not how often do you guys clean your K&N air filters?

 

[seanpistol]

i run a k&N, but i don't drive in dusty or bad conditions at all. i checked my filter 2 months after i got it, and it was barely dirty. it's been that way the entire year that i've had it. if you're constantly in dirt and dust, it may not be the best choice for you.

 

[patternman]

I've read lots of threads about the K&N's lack of filtering smaller dust particles without a prefilter which defeats the airflow capability. K&N's own site in the FAQ's also mentions this! If you would like to input on this just use your thread title (K&N air filter good or bad) and do a Google search you'll find plenty!
I have seen a high flow alternative that claims to filter to 5 micron. I haven’t tried them so I am unable to give a personal recommendation. You can read about them at: http://www.greenfilterusa.com/default.asp

 

[Agnem]

I've run K&N's on all my vehicles, and have no complaints about them. My oil analysis reports are proof that there is no concern for me. One problem with K&N filters is that they are user servicable. Meaning, that in a large way, the end user is partly responsible for how well they filter, based on proper use of the cleaning and recharging kit. This is a factor in how satisfactory the results are for different people over time.

 

[fsSnowboard]

i use a K&N and its helped increase airflow. I think you do have to be carefull if you live in an area with fine dirt/dust because that could pass through. But, if you keep the filter clean and well oiled with the recharge oil it should work fine. Furthure, i am going to put a K&N on my motorcycle, and a K&N cold air on my fiance's car, so i do like the product.

 

[Max Power]

Paper filters definately filter better then the K&N.

A member of dieselplace did a ISO 5011 test on a bunch of filters including the AC delco and K&N. Check out the results:
http://www.duramax-diesel.com/spicer/index.htm

 

[patternman]

Paper filters definately filter better then the K&N.

A member of dieselplace did a ISO 5011 test on a bunch of filters including the AC delco and K&N. Check out the results:
http://www.duramax-diesel.com/spicer/index.htm

That test is an eye opener!

 

[Mr_Roboto]

I run a K&N. I read the various opinions, and I'm kind of on the ledge. I won't buy another one, but I won't quit using the one I have.

I'm betting for the average person that never changes their filter anyways, the K&N is better since it has much more capacity for dirt.

I originally went with the K&N for my van because nobody, not even the dealer, had a paper filter (the van filter is a little shorter than the pickup filter so is a different part number).

 

[Max Power]

I run a K&N. I read the various opinions, and I'm kind of on the ledge. I won't buy another one, but I won't quit using the one I have.

I'm betting for the average person that never changes their filter anyways, the K&N is better since it has much more capacity for dirt.

I originally went with the K&N for my van because nobody, not even the dealer, had a paper filter (the van filter is a little shorter than the pickup filter so is a different part number).

According to that test K&N Doesn't have more dirt capacity.

 

[ClassicIDI]

As Mel Said K&N's are serviced by the user and this cause's mistakes. I run one in my truck and would never put a paper filter in any car I buy again. I run one in my truck, Jeep, Dirt Bike, and ATV. The bike and quad and Jeep are ridden in some of the dustiest conditions ever and I am religious about checking the air tube to the carb or intake for dirt but never have I seen any. I think the biggest mistake people make with K&N's are not enough grease on the rubber seal when it is installed. Just because they run out of the little tube that comes with the filter they stop but that is a big mistake. Just get some waterproof grease and really make sure that it is sealed. I have ridden my quad in the Moab sand dunes for hours come back to camp found the filter plugged but not a trace of dirt in the tube to the carb.

 

[Mr_Roboto]

According to that test K&N Doesn't have more dirt capacity.

The problem is those aren't real world tests. They are accelerated tests dumping lots of "dust / dirt etc" into the filter in a very short time. I spent some time in the accelerated testing business, it is used as a development tool, not as something definitive.

One of the benefits of the K&N is that it uses depth filtration. Dirt sticks to the cotton gauze and absorbs oil, and the dirt becomes part of the filter media itself, trapping more dirt. It's dirt stopping efficiency actually increases with time. The same concept is used in some high end furnace filters.

Find 50 people with IDI diesel trucks and OEM air cleaner housings, and split them randomly in half. Give half K&N filters, and half Motorcraft paper filters and seal the housings for a year. That kind of test would give you real world results.

 

[shorthair]

got a k&n on the wife's explorer got an accell kool-blue on the idi like em both but the k&n cost 30% more than the accell.

 

[bikepilot]

Flow and filtration aren't necessarily diametrically oposed. Simply increasing surface area of a given filter medial will typically improve flow, but of course doesn't hurt filtering ability. In my experence with off road race bikes (motocross, enduro etc) oiled foam (usually at least a half inch thick) has proven the best option. It typically flows and filters better than paper and filters way better than oiled gauze (i.e. K&N style filters). Of course an off road race machine is in a much dirtier environment than a truck normally will be in. Of course you need a certain amount of air box volumn and surface area to make oiled foam work and they do require maintance, but on a off road bike your changing the filter every race anyway.

In pratice, I suspect that with a given filter volumn its going to be very hard to flow better than paper with equal filtering ability, but if you could implement a larger air box with a larger filter you could probably improve both flow and filtering.


just my 2c.

 

[krawlr]

My problem with K&N's is the seal. In some cases they just don't make a complete seal in the housing they are used in and the dirt goes around them. In the cases where it doesn't rely on the filter rubber or a cone style clamped on a tube they're fine.

 

[rubberfish]

I run a K&N style filter on the street.
For dusty logging roads,,a large paper filter.
Although, the few times I have run my n&n
in the bush, there was no dirt in the intake tube.