honesT
08-01-2011, 06:03 PM
I have been researching Air intake ideas and came across what I think is well explained info about the K&N filters with some good points on why OFF ROAD 4X4 people should not use them,
Quote: Somewhere in the fine print it read that "off road applications require service intervals as soon as 100 miles" :spongebob:
To me changing from the K&N(street use) to factory for dirt sounds like good advice.95% of the time my Jeeps are to and from work and the bit better gas mileage from the K&N's help.I'll switch back to the foam & paper when I go under very dusty conditions off road.
K&N started as a drag racing supplier, and the filter design still shows the roots -- high flow, short runs, low saturation environment, short maintenance cycles. For racing (but not off-road racing!), K&N is good. Yes, K&N products have been independently examined, largely by the automakers or their contracted labs. I'm not at liberty to discuss internal DC activities, and I'm not privy to other automakers' policies based on any technical results, and -- as I said -- I've been out of the loop for a couple of years. But I would pay special attention to the following factors:
1) No K&N filters are used on any warranty-covered trucks or SUVs.
2) K&N has, in the past, specifically stated that its filters may not satisfy warranty requirements in vehicles used in extended severe driving conditions. Taking any vehicle down a dirt road is a "severe driving condition," and "extended" means 5% or more of the total vehicle runtime.
3) K&N has made a large number of applications to the automakers for warranty coverage for its products. Few, if any, have been granted by the automakers before now.
4) K&N recommends a radically different off-road service specification (what you found, Lou.Fab in the fine print).
5) Any oil evaporates, or loses effective filtration coefficient as it is contaminated. When that small amount of fine oil is gone, suspension is lost, and there's no protection. The engine inhales dirt. When a paper filter clogs, the engine lives on, even if it does starve.
You can do two tests yourself.
First, hold a K&N filter up to a bright light source, and look down between the pleats. You'll see unobstructed light shining through "pinholes" of up to one-half mm. The pinholes provide much of the flow characteristics of the filter. Dirt getting through the pinholes have a probability of adhering to the oiled fiber further up in the pleats, but it's only a probability. Over 50-100K miles, a lot of dirt will over come the long odds and find its way into the engine -- much more if you drive in dirt, or you suffer oil evaporation and loss of suspension.
Second, scrub out your filter box, and place a thin piece of white cotton cloth beneath the K&N, between the filter and the intake -- something like thin diaper cloth. Tape it or use a screen so it doesn't get s u c k e d in. Drive around for a few days, go find some unpaved roads. Check the cloth. You'll see a fine sheen of oil being lost from the K&N (bad!), and you'll also see the dirt your engine is inhaling. Do the same with the paper/foam filter. Compare the results.
Long post. Conclusion: road racing -- K&N GOOD. Off-road or on in high saturation environments (like downtown driving) -- K&N not so good, unless you recharge/re-oil weekly. Like to hear what you found out.
If you want to read the whole post by LOU.Fab click here and scroll down to post # 14 http://www.jeepsunlimited.com/forums/showthread.php?t=35390
Quote: Somewhere in the fine print it read that "off road applications require service intervals as soon as 100 miles" :spongebob:
To me changing from the K&N(street use) to factory for dirt sounds like good advice.95% of the time my Jeeps are to and from work and the bit better gas mileage from the K&N's help.I'll switch back to the foam & paper when I go under very dusty conditions off road.
K&N started as a drag racing supplier, and the filter design still shows the roots -- high flow, short runs, low saturation environment, short maintenance cycles. For racing (but not off-road racing!), K&N is good. Yes, K&N products have been independently examined, largely by the automakers or their contracted labs. I'm not at liberty to discuss internal DC activities, and I'm not privy to other automakers' policies based on any technical results, and -- as I said -- I've been out of the loop for a couple of years. But I would pay special attention to the following factors:
1) No K&N filters are used on any warranty-covered trucks or SUVs.
2) K&N has, in the past, specifically stated that its filters may not satisfy warranty requirements in vehicles used in extended severe driving conditions. Taking any vehicle down a dirt road is a "severe driving condition," and "extended" means 5% or more of the total vehicle runtime.
3) K&N has made a large number of applications to the automakers for warranty coverage for its products. Few, if any, have been granted by the automakers before now.
4) K&N recommends a radically different off-road service specification (what you found, Lou.Fab in the fine print).
5) Any oil evaporates, or loses effective filtration coefficient as it is contaminated. When that small amount of fine oil is gone, suspension is lost, and there's no protection. The engine inhales dirt. When a paper filter clogs, the engine lives on, even if it does starve.
You can do two tests yourself.
First, hold a K&N filter up to a bright light source, and look down between the pleats. You'll see unobstructed light shining through "pinholes" of up to one-half mm. The pinholes provide much of the flow characteristics of the filter. Dirt getting through the pinholes have a probability of adhering to the oiled fiber further up in the pleats, but it's only a probability. Over 50-100K miles, a lot of dirt will over come the long odds and find its way into the engine -- much more if you drive in dirt, or you suffer oil evaporation and loss of suspension.
Second, scrub out your filter box, and place a thin piece of white cotton cloth beneath the K&N, between the filter and the intake -- something like thin diaper cloth. Tape it or use a screen so it doesn't get s u c k e d in. Drive around for a few days, go find some unpaved roads. Check the cloth. You'll see a fine sheen of oil being lost from the K&N (bad!), and you'll also see the dirt your engine is inhaling. Do the same with the paper/foam filter. Compare the results.
Long post. Conclusion: road racing -- K&N GOOD. Off-road or on in high saturation environments (like downtown driving) -- K&N not so good, unless you recharge/re-oil weekly. Like to hear what you found out.
If you want to read the whole post by LOU.Fab click here and scroll down to post # 14 http://www.jeepsunlimited.com/forums/showthread.php?t=35390