K&N Drop In Air Filter
JK Super Freak
Joined: Oct 2007
Posts: 1,595
Likes: 0
From: The Badlands (near Lafayette, IN)
Wow. Lots of opinions here. Like buttholes, everybody has one, and most of them stink.
The CEL came on when I installed K&N in my first F150. It had the 4.6 V8.
No CEL in my '02 F150 with the 5.4
In both trucks, I improved power and MPG.
Same improvements with my wife's Expedition 5.4.
I can't say I notice a power difference with the JK.
I'm still calculating MPG, but the extreme cold recently has kept the tranny out of OD longer until the fluid warmed up. Even so, I'm still getting about 1 MPG more than the stock filter after putting the K&N back in.
It is entirely possible to change airflow by only changing a filter, without losing particle filtration. The goal is to increase surface area. The more surface area through which air can pass, the more air can pass at a given pressure differential. Don't believe me? Cover up 95% of your existing air filter with duct tape and see how poorly your vehicle performs. Pleats are an effective way to increase surface area without increasing size. Why do you think all air filters have pleats? Oil in the K&N filter is there to attract dirt/dust particles. Oil is almost like a dirt/dust magnet. (Before our modern throwaway mentality, oil intake filters were quite common.) It helps make up for some of the porosity of cotton versus paper.
The CEL came on when I installed K&N in my first F150. It had the 4.6 V8.
No CEL in my '02 F150 with the 5.4
In both trucks, I improved power and MPG.
Same improvements with my wife's Expedition 5.4.
I can't say I notice a power difference with the JK.
I'm still calculating MPG, but the extreme cold recently has kept the tranny out of OD longer until the fluid warmed up. Even so, I'm still getting about 1 MPG more than the stock filter after putting the K&N back in.
It is entirely possible to change airflow by only changing a filter, without losing particle filtration. The goal is to increase surface area. The more surface area through which air can pass, the more air can pass at a given pressure differential. Don't believe me? Cover up 95% of your existing air filter with duct tape and see how poorly your vehicle performs. Pleats are an effective way to increase surface area without increasing size. Why do you think all air filters have pleats? Oil in the K&N filter is there to attract dirt/dust particles. Oil is almost like a dirt/dust magnet. (Before our modern throwaway mentality, oil intake filters were quite common.) It helps make up for some of the porosity of cotton versus paper.
JK Jedi
Joined: Oct 2007
Posts: 5,537
Likes: 0
From: Colorado
Based on the very modest gains I've gotten with the full Airaid CAI, I can't imagine any drop in filter offering anything in the way of a noticeable improvement. While I don't have any empirical evidence at hand, I've heard that the stock paper filter has higher flow characteristics than that of the stock airbox, meaning it is not limiting airflow factor, the assembly is. FWIW.
JK Enthusiast
Joined: Feb 2007
Posts: 199
Likes: 0
Based on the very modest gains I've gotten with the full Airaid CAI, I can't imagine any drop in filter offering anything in the way of a noticeable improvement. While I don't have any empirical evidence at hand, I've heard that the stock paper filter has higher flow characteristics than that of the stock airbox, meaning it is not limiting airflow factor, the assembly is. FWIW.
The advantage of the brute force is simply more surface area and a dry filter.
The disadvantage is much more exposure to water.
I live in dusty Arizona deserts and so the dry filter option seemed the better way to go.
The only actual performance gain I've seen is a tiny tiny bit more pep at the low end.
Otherwise the only thing is it does sound more throaty etc... I.E. louder and growlier.
I kept my stock setup as it seemed to me easier to mod into a true water proof snorkel.
I've only ever been in situations that could have used a snorkel twice.
So the cost isn't warrented as yet.
I'd like to know more about "pre-filtering". Think I'll go do a google or 20.
Stay loose. Have fun. Make it home.
JK Newbie
Joined: Sep 2007
Posts: 25
Likes: 0
From: Hanging Rock--Roanoke County--Virginia
Pre filters
[/quote]The advantage of the brute force is simply more surface area and a dry filter.
The disadvantage is much more exposure to water.
I live in dusty Arizona deserts and so the dry filter option seemed the better way to go.
The only actual performance gain I've seen is a tiny tiny bit more pep at the low end.
Otherwise the only thing is it does sound more throaty etc... I.E. louder and growlier.
I kept my stock setup as it seemed to me easier to mod into a true water proof snorkel.
I've only ever been in situations that could have used a snorkel twice.
So the cost isn't warrented as yet.
I'd like to know more about "pre-filtering". Think I'll go do a google or 20.
Stay loose. Have fun. Make it home.[/QUOTE]
Check out Outerwearsdotcom
The disadvantage is much more exposure to water.
I live in dusty Arizona deserts and so the dry filter option seemed the better way to go.
The only actual performance gain I've seen is a tiny tiny bit more pep at the low end.
Otherwise the only thing is it does sound more throaty etc... I.E. louder and growlier.
I kept my stock setup as it seemed to me easier to mod into a true water proof snorkel.
I've only ever been in situations that could have used a snorkel twice.
So the cost isn't warrented as yet.
I'd like to know more about "pre-filtering". Think I'll go do a google or 20.
Stay loose. Have fun. Make it home.[/QUOTE]
Check out Outerwearsdotcom
Last edited by Bluewaterrider; Feb 23, 2008 at 10:30 AM.
JK Enthusiast
Joined: Jan 2008
Posts: 142
Likes: 0
From: nashua, nh
To each to his own.
my opinion: I have used K&N, air raid & AFE CAI and filters and run them in probably some of the harshest dustiest conditions during the summer months on forestry roads following logging & lowbed trucks spitting up endless amounts of fine particles of silt/sand and clay particles. I found the K&N, AFE & air raid high flow air filters did just as well if not better than a stock filter for these dust particles. I found you save money on these filters as I was changing stock filters every 3 weeks because of the dust.
Yes I had to recharge and clean the high flow filters just as often...but the recharge kit was cheaper (2 or 3 applications) than one stock filter. The oiled filters I cleaned/recharged every 3 weeks as well UNTIL I got a prefilter for them. The prefilter works great does not restrict your airflow and reduces the amount of times you clean/re-oil your filter as well adds more protection to filter the smaller particles of dust.
For people that have been getting oil into the intake tubes......YOU OVER OILED your filter and did not allow it to dry long enough. I have not had an issue with dust getting past the filter in the last 10 years of using the rechargeable high air flow filters on my pick-ups, especially when using Pre-filters.
With any K&N & AFE type reusable filter....if you check your air filter regularly, clean it, recharge it, add a pre-filter....you will get the best of both worlds...a small performance gain, possible MPG gain & filter particles just as good if not better than a stock filter and save money in the long term life of the vehicle with a reusable filter vs stock throw away.
my opinion: I have used K&N, air raid & AFE CAI and filters and run them in probably some of the harshest dustiest conditions during the summer months on forestry roads following logging & lowbed trucks spitting up endless amounts of fine particles of silt/sand and clay particles. I found the K&N, AFE & air raid high flow air filters did just as well if not better than a stock filter for these dust particles. I found you save money on these filters as I was changing stock filters every 3 weeks because of the dust.
Yes I had to recharge and clean the high flow filters just as often...but the recharge kit was cheaper (2 or 3 applications) than one stock filter. The oiled filters I cleaned/recharged every 3 weeks as well UNTIL I got a prefilter for them. The prefilter works great does not restrict your airflow and reduces the amount of times you clean/re-oil your filter as well adds more protection to filter the smaller particles of dust.
For people that have been getting oil into the intake tubes......YOU OVER OILED your filter and did not allow it to dry long enough. I have not had an issue with dust getting past the filter in the last 10 years of using the rechargeable high air flow filters on my pick-ups, especially when using Pre-filters.
With any K&N & AFE type reusable filter....if you check your air filter regularly, clean it, recharge it, add a pre-filter....you will get the best of both worlds...a small performance gain, possible MPG gain & filter particles just as good if not better than a stock filter and save money in the long term life of the vehicle with a reusable filter vs stock throw away.
Do not over oil them, and let then dry a bit. Else the first fire up they will coat the intake manifold which can collect dust. been using K&N filters for 30 years in all my cars/truck without a single issue.
JK Enthusiast
Joined: Feb 2008
Posts: 149
Likes: 0
Monumental waste of money...keep it stock, and change the paper filter q 180 days or less...I worry a lot less about paper filters in landfills then I do about the overpriced plastic bottles of gourmet water I see in our waterways and landfills.
Last edited by Dustoff '68; Feb 24, 2008 at 11:13 AM.
JK Enthusiast
Joined: Dec 2007
Posts: 266
Likes: 0
From: Mt Laurel NJ
Hey how bout this. True story!!! One of my junker vehicles is a 1998 mustang.I had it since new 110 miles. I took the complete air filter out around 45000 miles wanted to see if increased the acceleration. IT DID!!! (Dumb idea I guess) Since then I have 175000 miles on it (still no air filter) and the engine purrs. Trans is a different story. Think this was just dumb luck or does an air filter really not matter.
Now of course I would never run without an airfilter on my jeep off roading, but thought you should know maybe normal dust and dirt really doesn't hurt. Never needed to replace injecters or anything with the fuel system or engine.
Now of course I would never run without an airfilter on my jeep off roading, but thought you should know maybe normal dust and dirt really doesn't hurt. Never needed to replace injecters or anything with the fuel system or engine.
JK Newbie
Joined: Sep 2007
Posts: 25
Likes: 0
From: Hanging Rock--Roanoke County--Virginia
They Are Out There!!
Hey how bout this. True story!!! One of my junker vehicles is a 1998 mustang.I had it since new 110 miles. I took the complete air filter out around 45000 miles wanted to see if increased the acceleration. IT DID!!! (Dumb idea I guess) Since then I have 175000 miles on it (still no air filter) and the engine purrs. Trans is a different story. Think this was just dumb luck or does an air filter really not matter. Now of course I would never run without an airfilter on my jeep off roading, but thought you should know maybe normal dust and dirt really doesn't hurt. Never needed to replace injecters or anything with the fuel system or engine.
Now of course I would never run without an airfilter on my jeep off roading, but thought you should know maybe normal dust and dirt really doesn't hurt. Never needed to replace injecters or anything with the fuel system or engine.Carlos says "DE DE DEE"
