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Is a K&N air filter worth it?

K&Ns are junk. while they do flow better then a quality paper filter (Wix, AC Delco), flow and filtration are inversely proportional. if you increase flow, you reduce filtration. K&Ns allow the dust from road salt and sand to pass into the engine, which ends up in the cylinder and crank case. used oil analysis of vehicles with K&N filters show much higher levels of silica (sand) then the same vehicle with a paper filter. the contaminants cause excessive wear to the rings and bearing.

as far as power goes, i have talked to several drag racers running carburated small blocks that stopped using K&Ns after finding that is made no difference in either ET or trap speed, trap speed being a very good indicator of horsepower. on crown victorias with drop in panel filters, we have found that the K&N filters show a LOSE of 1rwhp. K&Ns also have a tendency to foul MAF sensors on modern fuel injected vehicles, they also skew the MAF reading causing a lean condition. Lean conditions can cause slight improvements in gas mileage. a lean mixture can also cause detonation, which can put holes in pistons.

GM has also linked cotton-gauze filters to transmission failure in vehicles with electronically controlled transmission.

ISO 5011 air filter test.
http://www.duramax-diesel.com/spicer/index.htm
 
All these horror stories about K&N are why I'm going to run the AEM. For those dead set on running an oiled cotton filter should try an Airaid. Airaid has an extra layer of protection. I was going to give the Airaid a try, but the oil-less AEM appealed to me because I'm lazy and the oil-less do not attach the sand. Too bad the two tests on this thread don't have any results of these two filters compare the K&N.
 
I'm watching these debates a lot more now. I only have a K&N in my Tracker but I used to run them in EVERY vehicle I owned.

10 years ago I had a '92 Blazer K1500 with a TBI 350 that went immediately from 13mpg to 14.5mpg around town and saw a good 3mpg gain on the highway. Literally the next tank after the filter saw higher gas mileage. VERY happy with those results. MPG remained like that until I moved to Cali and the Cali goosoline and 33's I put on it sucked up the improvement.

Since then some of the vehicles I have run them in (all 4x4's of various sizes) have seen small improvements while others haven't noticed anything.

With that same Blazer I once sucked a bunch of muddy water in and had the engine die because the dist got wet. Had a tide mark half way up the filter from the muddy water but none got through it. That right there was awesome.

However I have also seen the K&N oil get inside of the intake tubes. Is it bad? Dunno. With all the debates folks have now I've taken a gander at the AEM filters mentioned above and also am considering WIX or AC Delco filters. Big Ugly has a paper filter and will continue to have one until I do something different with the intake. Same with the wife's XL7...a K&N wouldn't give me much of an improvement so I'm not going to install one and then listen to my new doubts.

Of course I also used to be into all kinds of bolt ons and now I basically won't touch a good running engine outside of better air intake and exhaust systems.
 
I installed one of the K&N filter kits on my 94 F150 shortly after I first bought it. It sounded a little more throaty when hitting the throttle, but I didn't pick up any mpg and couldn't feel any HP increase. Hard to tell without putting it on an dyno... I doubt that I would buy it again.
 
It really depends on the vehicles and their air intake systems. Some have really crappily designed air intakes that are just dying for SOMETHING to let them breath better while many have well designed intakes and a K&N won't do diddly for them.

I forgot to mention my buddy's 92 Toyota 4x4 pickup with the 3.0L V6. They have the air intake squished in that bay because the engine is squished in as well...threw the K&N in and it was a gain you could literally feel without any doubts.
 
ciffer said:
K&Ns are junk. while they do flow better then a quality paper filter (Wix, AC Delco), flow and filtration are inversely proportional. if you increase flow, you reduce filtration. K&Ns allow the dust from road salt and sand to pass into the engine, which ends up in the cylinder and crank case. used oil analysis of vehicles with K&N filters show much higher levels of silica (sand) then the same vehicle with a paper filter. the contaminants cause excessive wear to the rings and bearing.

as far as power goes, i have talked to several drag racers running carburated small blocks that stopped using K&Ns after finding that is made no difference in either ET or trap speed, trap speed being a very good indicator of horsepower. on crown victorias with drop in panel filters, we have found that the K&N filters show a LOSE of 1rwhp. K&Ns also have a tendency to foul MAF sensors on modern fuel injected vehicles, they also skew the MAF reading causing a lean condition. Lean conditions can cause slight improvements in gas mileage. a lean mixture can also cause detonation, which can put holes in pistons.

GM has also linked cotton-gauze filters to transmission failure in vehicles with electronically controlled transmission.

ISO 5011 air filter test.
http://www.duramax-diesel.com/spicer/index.htm
Click to expand...
\
You got any real proof to back up all your BS.................???????

All I have to say about that is:haha::haha::haha::haha::haha::haha::haha::haha::haha::haha:

Try running a paper filter thru a deep water hole and tell me how gooood they are.
Rum a paper filter hundreds of miles thru desert dust bowls and thick dust clowds and tell me paper is the best.
Please Tellllll me...............
 
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ciffer said:
K&Ns are junk. while they do flow better then a quality paper filter (Wix, AC Delco), flow and filtration are inversely proportional. if you increase flow, you reduce filtration. K&Ns allow the dust from road salt and sand to pass into the engine, which ends up in the cylinder and crank case. used oil analysis of vehicles with K&N filters show much higher levels of silica (sand) then the same vehicle with a paper filter. the contaminants cause excessive wear to the rings and bearing.

as far as power goes, i have talked to several drag racers running carburated small blocks that stopped using K&Ns after finding that is made no difference in either ET or trap speed, trap speed being a very good indicator of horsepower. on crown victorias with drop in panel filters, we have found that the K&N filters show a LOSE of 1rwhp. K&Ns also have a tendency to foul MAF sensors on modern fuel injected vehicles, they also skew the MAF reading causing a lean condition. Lean conditions can cause slight improvements in gas mileage. a lean mixture can also cause detonation, which can put holes in pistons.

GM has also linked cotton-gauze filters to transmission failure in vehicles with electronically controlled transmission.

ISO 5011 air filter test.
http://www.duramax-diesel.com/spicer/index.htm
Click to expand...

There are too many circumstances to claim that K&N air filters cause more crap to get into the oil. Such as driving conditions, seasonal weather, time spent running (not just actual mileage), and how hard the engine was opporated during that oil change interval.
 
Thunder said:
\
You got any real proof to back up all your BS.................???????

All I have to say about that is:haha::haha::haha::haha::haha::haha::haha::haha::haha::haha:

Try running a paper filter thru a deep water hole and tell me how gooood they are.
Rum a paper filter hundreds of miles thru desert dust bowls and thick dust clowds and tell me paper is the best.
Please Tellllll me...............
Click to expand...

if a K&N saves your engine from water when running through water, great, i am not arguing against that.

take a look at the link i posted about the duramax air filter. K&Ns do not filter as well as the paper element filters. K&Ns show less pressure drop across the filter (less restrictive) then paper filters in every test i have seen. the AC Delco filter in the test shows the best filtration, but has the most restriction, i reason to believe that the AC Delco filter tested is the filter for very dusty condition.

flow and filtration are inversely proportional, there is no way around it. a K&N will NOT filter as well as an equivalent paper filter, but it WILL have less restiction.

i have not personally witnessed a dyno test on a C/K so i can not say what the effect of a K&N filter is on a C/K truck. i have witnessed dyno runs on a crown victoria with the only change being a K&N drop-in panel filter, the dyno showed a lose of 1rwhp. the result will be different for all vehicles.

unless someone can show me dyno sheets showing an the average of 3 consecutive dyno runs with a paper filter, followed by 3 consecutive runs with the ONLY change being a K&N filter i do not believe any change in power be it an increase to a decrease.

i used to run K&N filters, i stopped because i am concerned with filtration. if a K&N saves you from hydro locking your engine while running through water, great, run one, the filter is much cheaper then an engine.

i do not drive through deep water, just roads and crop fields, filtration is my only concern. quality paper filters changed regularly are cheaper then an engine.

engine modifications will require more air, especially at high RPMs. a modified engine might require more air then the stock filter can flow, in which case, a K&N would help, so would a 6 inch tall filter.
 
While I am not for or against K&Ns (I am going to run the new airaid dry filter) if you are getting oil anywhere past the filter you are overoiling your filter.

That said I have run K&Ns on several vehicles and for an open element I like them. Basically cause they are tougher than a paper filter.
 
I ran one on my 95 GMC Yukon for quite some time then finally changed back to a paper filter. Maybe I was over oiling it, I don't know, but my TBI had to be cleaned a number of times. I finally chucked the K&N when I was changing it one day and I held it up towards the sun and looked through the media - I was amazed by how much sunlight was peaking through - appeared to be alot of areas where the media was so thin it looked like the media had been pin pricked.

I am running them on my carburated 400 sbc and my bbc, but I am keeping a close eye on the condition of the media and at some point I will replace them with a paper element.
 
ciffer said:
i have witnessed dyno runs on a crown victoria with the only change being a K&N drop-in panel filter, the dyno showed a lose of 1rwhp. the result will be different for all vehicles.

unless someone can show me dyno sheets showing an the average of 3 consecutive dyno runs with a paper filter, followed by 3 consecutive runs with the ONLY change being a K&N filter i do not believe any change in power be it an increase to a decrease.
Click to expand...
Of course that is not the right way to conduct such a test. You have to swap back and forth between filters. Running all 3 pulls on one condition in a row lets you confound the results with other variables, like temperature of the engine bay, air conditions, etc.
 
If the 3 tests started under the same conditions, the figures should be comparable anyways, even if they show diminshing gains or losses. Of course, the poster may come back and say it was a climate controlled environment.
 
Guys, It makes perfect sense that if you are running a pocket rocket up and down the interstate, then a low restriction filter is more desireable. But if you are running an off-road vehicle and stirring up mud and dirt, then you want to filter as much particulate matter as possible.
Run K&N in your Honda CRX, but a WIX or AC in your K5.
 
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