K&N Filter Efficiency Tests

I've thought about which forum to start this thread in, and I finally decided on the Diesel Discussion forum because these tests were performed on a Chevy Duramax diesel.

Enjoy...


Edit
This link is bad, if you know of one to replace it, please add it to this thread.
http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

[H2O2]

Thanks, it just confirms my worst suspicions. Please don't waste your money and potentially harm your engines with this hazardous snakeoil.

[whunter]

Please put a K&N filter on every engine you own, your mechanic needs the work.
The engine rebuilder wants you to.

The best reason to put a K&N filter on a car:
It looks cool as it destroys your engine.



Never put a K&N filter on an engine you want to last more than 8 seconds.

[MS Fowler]

WOW! That is an impressive report. Of course, EVERY decision in an automobile is a compromise. Many people chose better handling while sacrificing some comfort, Better brakes when they are hot, usually means a harder pedal before they warm up, Attractive styling or utility. Compromises everywhere.
You can't get increased airflow without allowing more dirt. Considering what (any) diesel engine costs to repair, I'll err on the side of protection and let the ricers win all the drag races. My car will still be on the road long after their vehicles have been crushed and recycled, ( barring accident, etc).
Hats off to a couple of guys who provided a great service.

[Pete Burton]

Worth the quick read - should be enough for even the most stubborn modifying proponent to realize that spending money to butcher whoops, I mean add a K&N filter to their diesel is one of the most ill informed and pointless action one could make!

Wow - Going to get a Stock filter on my ML55 ASAP. Just blew 60 bucks on the K&N.

[ayalar007]

You know what really pis$$es me off??? The fact that when I first got my diesel, I had no idea that this forum exsited. All I knew was that there was a company called Performace Products that made parts for Mercedes because a catalog was left in the trunk by my dad. Now I read this after installing a K&N filter (who by the way, Performance Products praises. This is a direct quote from the catalog: Easy Drop In Installation, Replaces Stock Filter, Better Airflow for Maximum Torque, Increased Gas Mileage, Million-Mile Warranty: Airflow to your engine is one of the most critical areas affecting the performance of your vehicle and one of the easiest areas to upgrade. Original equipment air filters on new vehicles are generally very restrictive. This is due to their paper construction that actually limits engine breathing. That's why we recommend K&N, the leader in filter technology as proven by their heavy use in both on and off-road racing)
now, without knowing about those numbers before I feel like such an idiot, for spending that kind of money.

I guess I'll have to mark that off to experince I guess. Does anyone know if AC Delco makes filters for our babies?? Thanks for the info VeeDubTDI

Hold up...This is the response i just recieved from K&N.

Dear Customer,

We have seen this report mentioned from other customers before. However,
there are many problems with both the findings and also the way in which
the tests were conducted. First, the data was collected with varying
conditions for every test. The largest discrepancies were in humidity
and temperature. The conditions that this test were conducted does not
actually follow the ISO 5011 standards. Also, using their own data
(which was gathered in an imprecise manner), the math for the K&N filter
is calculated wrong. Since the time this test was posted, the data
numbers has also changed more than a few times.

These discrepancies point to the validity of this test. K&N's are
routinely tested both in house and by independent 3rd party labs. In
every test, K&N's either match or outperform stock filters in the areas
of filtering efficiency, total dirt capacity, and airflow. Ford buys our
filters direct and sells them through their dealerships. More and more
dealerships of all manufacturers are buying our filters direct and
offering them for their customers. We have been making our filter for
almost 40 years. If there was any issue with filtering efficiency, we
would not be in business.

K&N is and has always been dedicated in providing a quality product that
matches or exceeds the OEM filter, helps improve performance, and
reduces waste by not having to throw away a paper filter every year.
Please feel free to contact us if you still have questions or concerns.

Thanks for writing,

Shaun McClure
Technical Support

[dannym]

WOW,
I had no idea K&N was that bad. I wasn't going to use one in my car but I do have one in my motorcycle. Where it is a common practice. I'm wondering now if I should take it out.

Danny

[aklim]

I used to have a 99 Ford Ranger and on the Ranger boards, people are having problems with the MAF when they have the K&N. Seems like the solution was to hose down the elements every so often with brake cleaner. Don't know why but early 90s Mustangs and pre 90 F-bodies didn't have problems with them. Seems like the latest MAFs now are having problems. Don't know why.

Look at the thickness in the filters, i guess that says it all!

[Tirebiter]

So, I've been ruining my engines for the last twenty seven years by using K&N filters. Oh dear.

Funny that I haven't noticed all the damage allegedly caused by these things.

I will make a sacrifice for all my fellow forum members and continue with my use of K&N filters as an experiment.

In another twenty three years I will have fifty years of experience with them.

I'll get back to you, eh?

[aklim]

Originally Posted by Tirebiter

So, I've been ruining my engines for the last twenty seven years by using K&N filters. Oh dear.

Funny that I haven't noticed all the damage allegedly caused by these things.

I will make a sacrifice for all my fellow forum members and continue with my use of K&N filters as an experiment.

In another twenty three years I will have fifty years of experience with them.

I'll get back to you, eh?

Like I said, in the early 90s, with Speed Density (no MAF) and with the MAF systems, they didn't hurt anything. What I hear from other boards is that in the late 90s they changed somethign about the MAF and now it hurts the filament wires. I have personally had a dead spot with my Ranger and when I cleaned the MAF, the spot went away.

[Hatterasguy]

MB doesn't make a restrictive airbox, the stock filters work fine. But hay throw one in you may get your diesel 1/10 of a sec faster in the quarter mile!


btw K&N filters use oil, this oil coats the MAF sensors on newer MB's. They run about $500-$700 each, usually their is 2.

[Pete Burton]

Originally Posted by SilentMethod

Hold up...This is the response i just recieved from K&N.

Dear Customer,

We have seen this report mentioned from other customers before. However,
there are many problems with both the findings and also the way in which
the tests were conducted. First, the data was collected with varying
conditions for every test. All tests have varying conditions. In this particular test, the variations are clearly stated, and statistically tiny compared to the results Check for yourself The largest discrepancies were in humidity and temperature. Typically within 1 degree Fahrenheit and a few percent in RH The conditions that this test were conducted does not actually follow the ISO 5011 standards.How is that? this is just stated here, but not even one specific example is mentioned Also, using their own data
(which was gathered in an imprecise manner)Again, claimed but not defined in any way, the math for the K&N filter
is calculated wrong. Since the time this test was posted, the data
numbers has also changed more than a few times.I missed this, but I can't say, of course, Mr. Mc Clure doesn't either)

These discrepancies point to the validity of this test.The small variability in these tests is pretty compelling to me K&N's are
routinely tested both in house and by independent 3rd party labs. In
every test, apparently not everyone, eh? K&N's either match or outperform stock filters in the areas
of filtering efficiency, total dirt capacity, and airflow. Ford buys our
filters direct and sells them through their dealerships. More and more
dealerships of all manufacturers are buying our filters direct and
offering them for their customers. We have been making our filter for
almost 40 years. If there was any issue with filtering efficiency, we
would not be in business. Filtering efficiency is ALWAYS a primary issue with FILTERS,
K&N is and has always been dedicated in providing a quality product that
matches or exceeds the OEM filter, helps improve performance, and
reduces waste by not having to throw away a paper filter every year.
Please feel free to contact us if you still have questions or concerns.

Thanks for writing,

Shaun McClure
Technical Support

this really burns me. Maybe because I design automated flow testing equipment. I hate it when anybody dismisses specific information with off the cuff generalizations.I've never tried a K&N filter and it looks like I never will. If Mr. McClure mentioned any specifics, I might have taken him seriously. Would YOU buy a used filter from this company?