How good are K&N filters?

LJameson · 03-16-2009, 12:08 AM

For last Christmas my parents got me a K&N Filter for my TJ. After reading on the forums that they don't give any significant increase in power or mileage, I couldn't justify the cost to buy one. Since I got this one for free, I figured theres no reason to not put it on. After I installed it, I noticed NO power increase or any gains in MPG. I wasn't dissapointed because I wasn't expecting it, but I though I'd just point that out. Today I was doing some common maintenance on my TJ and checked out the filter. After a couple of wheeling trips and 10,000 miles, it was a little dirty, but not terrible. But what caught my attention was my intake tube. It was just as dirty as the filter itself.

Nasty! I started researching the forum and found out how much the K&N really sucks. According to this link, http://duramax-diesel.com/spicer/index.htm, the K&N filter they tested not only let more dirt in then all of the others (except the UNI) but it was one of the quickest to clog up. Even looking at the sun with it, you can see how big some of the holes are in the filter:

Needless to say, instead of buying the K&N filter recharging kit, I decided to get the AC Delco Paper filter. I just thought I'd throw out my experience with the filters, and how it let more dirt into my engine. Bottom line: Save your money and buy paper element filters. K&N is not worth it.

**SaxManClay** · 03-16-2009, 07:49 AM

This is great. Just more proof not to get these things.

**Unlimited04** · 03-16-2009, 09:04 AM

I found the same thing with my AEM intake. CAI write up is in my sig. I'll link this K&N filter thread in there as well, feel free to copy your post here:Cold Air Intake FAQ or here: AEM Intake Observations

grandcherokee12 · 06-21-2009, 01:25 PM

Not supporting the idea of an aftermarket drop in filter, but when making claims about NO horsepower gains and NO increase in gas milage, use numbers, possibly a dyno pull. It's hard to tell if you gain horsepower just by the feeling in your body. And, any type of mpg gain/loss is extremely skewed by variables that you or I could never control. Therefore, personal preference always wins.

UTAH · 06-21-2009, 09:23 PM

I've been a member of the two largest Diesel sites for over 10 years. During that time I've seen the "K&N argument" come up repeatedly.

What concerns me is that the guys who do oil sampling/testing report higher silicon levels when using K&N filters. That means dirt/dust is getting through. K&N reps have responded to complaints by claiming that people aren't installing the filters right and the particles are getting around the seals.

Bill

JKbro · 10-04-2010, 05:05 PM

That's I prefer to go with aFe Air Intake Filters. They never disappoint.

**RogueSpear2023** · 10-04-2010, 08:59 PM

I had one in my Super Duty for two weeks and after reading how bad they were on the other forum, I pulled it out, looked in my intake and you could see the dust on the inside, it was clean before the K&N, I also changed my oil to be safe, then I through the K&N crap in the trash. I will never use them on any vehicle ever again.

Brewskiskeeter · 12-01-2010, 02:08 AM

I heard about K&N's being crap years ago. I also used to use them, after I heard they let more dust through, flow worse, and in the case of my friend, fouled out his o2 sensor, I'd never use them again. I'll stick to paper filters.

odinseye84 · 12-01-2010, 04:26 PM

Waste of money really... they dont filter nearly as well as stock, people clean them too often and over-oil them. You can get giant paper cone filters from certain model vehicles if you want higher flow and good filtering.

**RogueSpear2023** · 12-02-2010, 12:22 AM

Quote:

Originally Posted by odinseye84

Waste of money really... they dont filter nearly as well as stock, people clean them too often and over-oil them. You can get giant paper cone filters from certain model vehicles if you want higher flow and good filtering.

I agree my Super Duty I eventually went with a large paper cylinder filter from a Cat D9 Bulldozer, it worked very well, filtered better than stock, and flowed much more air that stock, I also put a pre-filter on it, a large black nylon, since the filters were around $60 a piece.

xWhite420wIDOWx · 12-02-2010, 12:28 AM

Once again this proves how cr@ppy they really are...

Brewskiskeeter · 12-02-2010, 10:47 AM

Why doesnt that duramax forum link to show how bad they are work anymore?
Do you think K&N reps got on there and made them remove it or something along those lines?

**MT_Ranger** · 12-02-2010, 10:59 PM

Quote:

Originally Posted by RogueSpear2023

I agree my Super Duty I eventually went with a large paper cylinder filter from a Cat D9 Bulldozer, it worked very well, filtered better than stock, and flowed much more air that stock, I also put a pre-filter on it, a large black nylon, since the filters were around $60 a piece.

If you have a filter service near you, they will wash those filters for you for about 1/2 the cost of new ones. You can do that a couple times usually before they need replaced.

empty · 12-03-2010, 08:40 PM

"more air" equals "more trash" in my opinion

**Keojoe1981** · 07-27-2011, 10:54 PM

10000 miles!!! that is a LOT of miles to ride on a filter without atleast cleaning the thing. Anyone who goes 10,000 miles without atleast cleaning their filter (reguardless of what kind of filter it is or what it is made of) is asking for more dirt/dust to get into their intake system. Especially if they have a (JEEP WRANGLER) and take it "OFF ROAD"... The quotations are not a way to put you down or yell at you in any way they are just my way of pointing out the "key" issues. The K&N air filter may not be the best air filter that someone can put in a vehicle, but if properly maintained, they should do MOST of what they they do... One thing that they may not do is add more hp gains... Most people change air filters first because they believe it gives them more airflow... Horsepower = how much air and fuel you can cram into an engine. It is a pretty simple concept... I am only writing this because I have put about 1,000 miles on my 2004 tj and the filter wasn't dirty at all. I only took it off roading 2 times though. Who knows I could be wrong and tomorrow after I get off of staff duty I can check and find that in the last 2 days since i checked it and find out that I was wrong... The bottom line is there is a recharging kit that comes with a cleaner and oil and if someone really wants to take care of their filter then they will clean it more often. poor maintainance= poor performance... Reguardless of what you are dealing with.. For poops and giggles I will buy a paper filter and try the other way... If you really want some hp gains you can increase the fuel/air mixture that goes into your engine. That is the key.. Please respond with mercy,

thanks, joe

06-21-2009, 09:23 PM	#5
UTAH Registered User Join Date: Jul 2003 Location: Salt Lake City Posts: 1,085 Profile Gallery Classifieds My Jeeps	I've been a member of the two largest Diesel sites for over 10 years. During that time I've seen the "K&N argument" come up repeatedly. What concerns me is that the guys who do oil sampling/testing report higher silicon levels when using K&N filters. That means dirt/dust is getting through. K&N reps have responded to complaints by claiming that people aren't installing the filters right and the particles are getting around the seals. Bill __________________ 2003 Rubicon auto w/3" TeraFlex System & 33" Goodyear MTR's TJ Ruby Pic 1 TJ Ruby Pic 2 2007 Unlimited X 6sp 4dr w/3" lift and 35" Pro Comp X-AT's JK X Pic 1 JK X Pic 2 2009 Grand Cherokee Laredo 4x4 2009 JK Sahara auto 4dr 4x4

10-04-2010, 05:05 PM	#6
JKbro Registered User Join Date: Sep 2010 Location: haines Posts: 3 Profile Gallery Classifieds My Jeeps	That's I prefer to go with aFe Air Intake Filters. They never disappoint.