K&N Air Filter Replacement Options

[Jerry Bransford]

As much as I love Farm Project's reviews, his biggest love for the K&N was his truck accelerated faster with it, not something many of us here think is more important than good filtration.

There was a lab test performed, in accordance with ISO (International Standards Organization) 5011 standards, that clearly showed the K&N to be the very worst at actually filtering the air. This is one of the charts from the lab test. Carefully read the lab's comments under the chart. Their words, not mine. I did 'bold' the last sentence but I did not change its wording.

 

[Gilaguy23]

I’m new here and was just browsing when I came across this thread. I have used K&N filters for many years on a variety of vehicles. My opinion is quite different than most of what I read. Never have I experienced any of the issues mentioned here. K&N filters do not void factory warranties. Why? I’ve used them in dirt bikes in the desert, ATVs, 4 wheelers, Duramax diesels, Tahoes, suburban, Ram trucks, Toyota truck, Highlander, still using on a GMC Envoy with 240k (on the other in-line 6 out there) that has had a K&N almost its entire life, and a few more. Never, ever had an issue and in the big engines breathing is everything. I recently purchased a 2006 Wrangler 4.0 and it soon will have K&N. Now I’ll back up my thoughts. Take any standard dirty air filter Fram etc, and blow air through it and see what you get. K&N filters are oiled for a reason, oil collects and TRAPS dirt, dry filters mostly just collect. One post said they could see light through it, yes! That’s where the oil comes it. If K&N was as bad for your engine as many of you have stated, they would have gone under 20 years ago. They are reusable as well.

Good lawyers. So I'll ask this, can you say based on facts a K&N provides better filteration than OEM paper filters? Just curious.

 

[sab]

I think K&N still exists because the damage from poor filtration is cumulative and takes many, many miles and hours of engine running to manifest. Most vehicles are on their third, fourth, or fifth owner by the time that occurs, and they have no idea why their engine lacks compression. I'm very loyal to my vehicles and keep rebuilding them. I've said before that my daily driver is a 1998 Subaru that I've owned for 18 years and has 375k on it now. I just rebuilt the engine to keep it running.

I jumped on the Jeep bandwagon late in life having purchased my LJ last June. I plan to keep the LJ until I can't climb into it anymore. The last thing I want to do with any of my vehicles is to create more work for myself by sending dirty air into the intake. Of course, my mindset is just one mindset. If you buy new cars every three years, or if .2 seconds from 0-60 MPH is important to you, a K&N filter looks pretty good, I'd suppose. I don't like it when others tell me I'm doing things wrong, so I'm not going to tell someone else that K&N is never the right option.

I think you should gather data, and make the right decision for you.

 

[sab]

K&N filters are oiled for a reason, oil collects and TRAPS dirt, dry filters mostly just collect. One post said they could see light through it, yes! That’s where the oil comes it.

The nature of all filtration, both liquid and gas, is the same - porosity of the filter medium allows the desired gas or fluid to pass, but prevents particulates from passing. These particulates accumulate on the filter medium. As they accumulate, the porosity decreases, and they filter finer and finer particles until, eventually, the pressure drop increases to a level that affects performance, necessitating cleaning or replacement of the filter element, depending on filter construction. Oiled filters use the oil as an additional means of trapping the particles. Oil both reduces the pore size and acts as a "glue" to grab the particles passing by. It's just a different way to filter, but it's like most other filters - use it long enough, and you'll notice a power loss because the filter porosity decreases with use. The trouble is - how big are the initial pores, and what environment do you operate the engine in? Big pores and dusty environments are troublesome for me.

 

[SSTJ]

This is one of the searches that got me reconsidering K&N filters. Though not a perfect lab-quality test, he is pretty thorough.

Wow. Yea, jump to 13:37 or 14:04 to see some damning results for K&N.

 

[Jerry Bransford]

As much as I love Farm Project's reviews, his biggest love for the K&N was his truck accelerated faster with it, not something many of us here think is more important than good filtration.

There was a lab test performed, in accordance with ISO (International Standards Organization) 5011 standards, that clearly showed the K&N to be the very worst at actually filtering the air. This is one of the charts from the lab test. Carefully read the lab's comments under the chart. Their words, not mine. I did 'bold' the last sentence but I did not change its wording.

View attachment 339789

@sab No comment on this? And you still like K&N after learning it passed 18X more dirt into the engine than the AC-Delco? Damn the ISO lab test results, full-speed ahead.

To see the entire air filter lab test results go to http://www.billswebspace.com/AirFilterTest.htm#:~:text=ISO 5011 Test:,are strictly monitored and controlled.

K&N went to great lengths trying to suppress those results, even resorting to buying some popular websites like Bob is the Oil Guy that had them posted so they could remove them.

 

[sab]

@sab No comment on this? And you still like K&N after learning it passed 18X more dirt into the engine than the AC-Delco? Damn the ISO lab test results, full-speed ahead.

Jerry - I've already said that I won't run a K&N in my LJ or my daily drivers. However, I have friends who've run race engines with essentially no air filter because their engines run for 10 seconds between rebuilds. There's a large spectrum of use cases out there.

 

[Jerry Bransford]

Racers and K&N air filters are fine, we just do our best here to steer Jeep owners away from them.

 

[NashvilleTJ]

I’ve got a souped up 75cc chain saw which runs a K&N - but in my defense it’s not a daily-cutting chain saw…

 

[sab]

Racers and K&N air filters are fine, we just do our best here to steer Jeep owners away from them.

I agree. In fact, I hope that's what I said in previous posts, but with more explanation (or blabbering, depending on one's perspective.) In fact, I've seen your previous postings of that chart, and I've had a stack of AC Delco filters in my shop for coming up on a year now! Thanks for the link to the actual study. I hadn't seen that before, and I intend to read it to get more info.

 

[sab]

I’ve got a souped up 75cc chain saw which runs a K&N - but in my defense it’s not a daily-cutting chain saw…

NashvilleTJ - if that were your daily-cutting chain saw, I'd be nervous to shake your hand!

 

[jrcotner]

Yesterday I replaced the K&N with an OEM air box. So far, I don't notice a difference in performance, which was allegedly the rationale for the PO making the swap.