K&N filters ?

[airron]

I have a 2006 F-250 diesel with 160,000 miles and no mods, it's all stock. My last 250 mile trip on the interstate running @ 70 on the cruise control (without the AS) I got 17.3 mpg. Towing our 27' International from Sarasota, Fl to Destin for the Canopener I got 12.3 mpg at 62-64mph on cruise. Of course the truck has no lack of power for pulling our AS. But, I was thinking of looking into getting a K&N air filter for the truck. Not just the air filter, but the complete cold air induction kit for the diesel. Why? Well, I would like to justify it by getting a real increase in MPG. Having more power for towing would of course be nice, one can never have too much pulling power. And I know the sound from the turbo spinning up would make me feel like a high school kid again. So, I'm asking for any real world experience with a K&N (or similar) air filter install. Any increase in MPG, better engine temps, more power,, improved sound etc. Thanks in advance.

[ROBERTSUNRUS]

Hi, this has been brought up before and I will say it again; Ford Motor Company has identified failures caused by these type air filters. They allow dirt into the turbos on Diesels and it eats up the vanes. On gas engines, the excess oil kills the Mas Air Flow Sensor. Hold one up to the light and it looks like a screen door. The dirt also passes through the engine. Not to mention the annoying sound you have to listen to all of the time you are driving/riding in this vehicle.

[RamblinManGa]

Hi from AZ. . .I have used K & N filters and/or cold air kits for years, the last 2 on Ford truck gas motors. Approximately 85k on them in total.No failures, no problems, no mass air flow sensors, nada ! Also no diesels, so I can't speak to them. Regards, Craig

[jcl]

Some good independent test results on the various diesel pickup forums.

Short story is less dirt holding capacity, and more dirt passing through the K&N filter. Pressure drop varied with dirt load, but didn't make any appreciable difference in total pressure drop through the intake. No hp or fuel economy gains to be had with just a filter change from stock, unless you have serious modifications requiring more airflow than the stock turbo requires.

Biggest impact of a CAI is often intake roar. Not turbo noise, but noise from the air passing through the intake itself. Some like it. Others find it intrusive.

Jeff

[jcl]

Airron:

Here is one of the studies I recall. It was based on a Duramax, so the base filter was an AC. The link includes the back story, which is worth reading. I think an AC filter is very similar to the OE Ford filter in design and construction, and the Dodge filter for that matter, although I have less experience with the Dodge product. I think there are trends illustrated here that can be extended across different engine and vehicle platforms.

ISO 5011 Duramax Air Filter Test Report

Jeff

[Ahab]

Originally Posted by RamblinManGa

Hi from AZ. . .I have used K & N filters and/or cold air kits for years, the last 2 on Ford truck gas motors. Approximately 85k on them in total.No failures, no problems, no mass air flow sensors, nada ! Also no diesels, so I can't speak to them. Regards, Craig

This guy is just plain lucky. I have had problems on Fords using the K&N filters. Don't waste your money, there is no benefit

[AtomicNo13]

My company fleet has more than 8 million miles over 20 Years use. K&n filters have led to zero failures of turbos or Maf sensor failure
Slander and mis info is rampant. People don't understand how these work. I am a fan through proven reliability.... no association other than being a fleet user.

[DKB_SATX]

Originally Posted by AtomicNo13

My company fleet has more than 8 million miles over 20 Years use. K&n filters have led to zero failures of turbos or Maf sensor failure
Slander and mis info is rampant. People don't understand how these work. I am a fan through proven reliability.... no association other than being a fleet user.

You have inadvertently touched on the real problem with K&N filters, though. People don't understand how they work, nor do they maintain them per K&N's instructions, and that can lead to problems.

Too little oil and the filters don't filter well enough. Too much oil on engines with a MAF downstream of the filter can foul the MAF.

Used and maintained properly, I don't think a K&N is an "engine destroyer" but I don't think they have the advantage over stock filtration that they did 30 years ago, and without other mods I don't think you'll see real benefits over a stock filter changed when it should be.

The tests that jcl linked to seem to strongly favor more conventional filters, at least in a diesel application.

[AtomicNo13]

I know people over maintain them....
Too much washing. They operate at peak efficiency when dirty.... not plugged.
Secondly too much oiling is not good but proven over and over will not fly out of the gauze and foul the Maf. Too much oil will certainly drip into the tube or blenum then be sucked along into the Airstream (no play on words).
The key is proper application and service. We as a matter of policy NEVER EVER wash ours in fewer than 100000 miles.

[jcl]

I agree that potential MAF problems can be avoided through proper maintenance and not over oiling. That doesn't always happen, unfortunately, but maintained properly you shouldn't have a problem with a MAF due to using an oiled filter. Lots of users have had problems, due to improper oiling.

The issue to me is their filtering, and the marketing claims of hp increases just by changing to an aftermarket filter. If you have a look at the ISO 5011 test I linked above (and there are more reports like this, not just this one) you see that oiled foam filters respond differently as they accumulate dirt. They start out at very low backpressure, but they climb much more quickly than a dry filter as they get clogged. They also pass a lot more dirt during their useful life, and hold far less until they need cleaning or replacing. If you get it full of dirt it may filter more, but the problem is then you have much more backpressure than a paper filter.

If hp is the ultimate goal, one would take the filter out altogether and accept increased engine wear. If maximizing engine life is important, use a good filter. Everyone has to decide where they are on that curve.

How much does that low backpressure matter, which is the way the oiled foam filters are usually marketed? Take a look at the unloaded and loaded backpressure figures in the link. The hp and fuel efficiency gains are not measurable, and are traded off for much more frequent maintenance, or performance degradation if that maintenance isn't spot on.

I do think that oiled foam filters have a very real advantage in some applications. If you are mud bogging or something similar, and need a filter that won't collapse when it gets wet, then a foam filter has definite advantages over a paper filter.

[AtomicNo13]

You mention foam in your post....
You know K&N does not use foam
?
It is made of a natural fiber... the only foam is in the form of a pre filter. A sleeve which fits over the actual filter.

[panheaddale]

Originally Posted by ROBERTSUNRUS

Hi, this has been brought up before and I will say it again; Ford Motor Company has identified failures caused by these type air filters. They allow dirt into the turbos on Diesels and it eats up the vanes. On gas engines, the excess oil kills the Mas Air Flow Sensor. Hold one up to the light and it looks like a screen door. The dirt also passes through the engine. Not to mention the annoying sound you have to listen to all of the time you are driving/riding in this vehicle.

I would like to see actual data from everyone posting opinions about K&N filters.The problem is not the K&N filter itself but the fitment to the stock ford airbox. The filter does not fit the stock airbox with an airtight seal therefore dust can enter the system by actually bypassing the filter. Any aftermarket filter you get needs to have the complete cold air box replaced so that it is all a matched set. Replacing the cold air injection by itself will give you very minimal if any gain in MPG. If you want the gains you would need to change the exhaust to a larger diameter exhaust, for one and in conjunction with the cold air box you will see some slight gain in MPG but even greater gains in power. Exhaust and air box are only a couple of mods to help gain MPG and power. In short DON"T just do a filter replacement and expect much if any gains.

[Tom Nugler]

The last K&N I used was in a 2 stroke Kawasaki. From what I've seen during the last 40 years in the Import Service business I would never recommend an aftermarket filter for use in a modern engine.
Poor installations, bad design and incorrect maintenance are all verifiable concerns.
A few months back another reason to avoid using these type of filters came from the VW/Audi Group. Regeneration of Diesel Particulate Filters can be impared by the use of aftermarket "cotton bed steel mesh" filters.
Replacing a DPR in a clean diesel can run about a $1000.
Big price to pay for dubious claims of increased power and performance.

Tom

[RickDavis]

I seem to recall that the Turbo Diesel Register (Dodge Magazine) did some testing a few years back and the results weren't too encouraging to say the least.
I don't have a link to it but it could probably be found if some one waned to search

[DKB_SATX]

Originally Posted by RickDavis

I seem to recall that the Turbo Diesel Register (Dodge Magazine) did some testing a few years back and the results weren't too encouraging to say the least.
I don't have a link to it but it could probably be found if some one waned to search

Frustrating. Finding metadata about the article was pretty easy, but they seem to have intentionally broken their website as far as accessing old articles, and the only other method I found would be to order a back issue or reprint. Having a gas-fired Ford I'm not THAT interested. Here's what I found, it lists the issues that contain the articles with test results.

In the quest for big horsepower numbers and lower exhaust gas temperatures, the TDR audience was busy experimenting with all different kinds of air intake and exhaust systems. Concurrently with members tinkering around, the aftermarket companies in air intake, specifically aFe, had discovered diesels, too. "Funnel Ram," big honkin' air filters, "Ram Air," "Magnum," and the standard K&N or other brand drop-in filters were all being discussed by TDR members.

Joe Donnelly tested several kinds of air filter arrangements with horsepower results of 549 for the stock factory filter to 574 using an aFe kit. Joe was also busy testing camshafts, piston bowl shapes, turbochargers, head porting, exhaust manifolds, etc. "Take me back" and you would realize that Joe and Lawrence Bolton of Diesel Dynamics spent eight months and 18 cam changes designing camshafts for the 12-valve engine. Whew!

As a follow-up to Joe's performance testing, we've since learned more about air flow, super-duper filters and—here's the key—cold air intake. The series of articles done in Issues 56, page 150; and Isue 59, page 130, tell the complete story. Bottom line: the engine likes cold air.

Likewise, Joe and the audience have learned a lot about turbochargers, specifically compound turbocharging. Check out Joe's updates in Issue 70, pages 90-92 (12-valve engine); Issue 60, pages 94-99 (HPCR engine).

[GCinSC2]

TDR did a big write up and I think many gave any oiled gauze/fabric combo a 2nd thought after reading it. I ran an AFE on my '05 until the article. Re Installed OE housing and paper filter etc. One unscientific observation, at each cleaning and re oiling I took a fresh towel and swabbed the air tube looking for ANY film or debris, never found any. If I would have found any film or dusting in the post filter tube, the system would have been scrapped on the spot. The Cummins moves a lot of air thru the intake. Proof, only that the air tube was clean to my simple inspection. I also had three engine oil analysis reports, no contamination issues.

Gary

[airron]

Well after more research on the web and replies from you guys, I think I'll put the idea of installing an after market air filter on hold for a while. Most of the buzz on other diesel boards was the same as here. It's a trade off ..... more air flow or less filtering of the incoming air but not both. And since the OEM equipment seems to work well enough I am going to leave it alone for now. Maybe I'll save up my money & buy some 20" spinners for my wheels instead. Thanks for the feedback.

[slowmover]

I first used K&N thirty years ago on a gasser. I wouldn't on a turbodiesel. If a DONALDSON Tru-Core (IIRC) is part of an upgrade. then, maybe.

Fuel economy is always a laudable goal. When one pursues that he also commits to longer component life (tires, brakes, etc) as FE is really a measure of how well one is doing in keeping reliability high over the longest period. Seen in this way, FE is about keeping ownership and operating expense at a lower point, which is expressed as cents-per-mile when one converts it all to a spreadsheet.

Actual FE improvement is a matter of percentage improvement to annual average mpg and this is where Americans lose interest. The discipline to record all miles and all gallons. Spending money to "save" money takes longer than first appears as one must first absorb the cost (say, $500) of an "improvement" . . and, factored into annual average miles it may be tens of thousands of miles necessary.

Honest_to_God easy mpg improvers are, for a 1T truck, changing to closed-shoulder, highway rib tires (1-2/mpg, all miles), as well as making sure of perfect mechanical baseline (mainly alignment, zero brake drag and no steering slop).

But the real improvements are in driver skill and include trip plannning. One can underwrite 5k miles of vacation travel annually through this alone. "Free" fuel is a decent incentive (based on an annual fuel budget where fuel is a constant price, but miles travelled increases).

In other words, do a better job of driving (combine trips, no idling, never use brakes, etc) and hauling that Airstream around becomes free. If the TV is as reliable a few years longer keeping one from replacement, then that has been the true measure of economy.

.

[panheaddale]

Originally Posted by slowmover

I first used K&N thirty years ago on a gasser. I wouldn't on a turbodiesel. If a DONALDSON Tru-Core (IIRC) is part of an upgrade. then, maybe.

Fuel economy is always a laudable goal. When one pursues that he also commits to longer component life (tires, brakes, etc) as FE is really a measure of how well one is doing in keeping reliability high over the longest period. Seen in this way, FE is about keeping ownership and operating expense at a lower point, which is expressed as cents-per-mile when one converts it all to a spreadsheet.

Actual FE improvement is a matter of percentage improvement to annual average mpg and this is where Americans lose interest. The discipline to record all miles and all gallons. Spending money to "save" money takes longer than first appears as one must first absorb the cost (say, $500) of an "improvement" . . and, factored into annual average miles it may be tens of thousands of miles necessary.

Honest_to_God easy mpg improvers are, for a 1T truck, changing to closed-shoulder, highway rib tires (1-2/mpg, all miles), as well as making sure of perfect mechanical baseline (mainly alignment, zero brake drag and no steering slop).

But the real improvements are in driver skill and include trip plannning. One can underwrite 5k miles of vacation travel annually through this alone. "Free" fuel is a decent incentive (based on an annual fuel budget where fuel is a constant price, but miles travelled increases).

In other words, do a better job of driving (combine trips, no idling, never use brakes, etc) and hauling that Airstream around becomes free. If the TV is as reliable a few years longer keeping one from replacement, then that has been the true measure of economy.

.

???

[69Silvrbelle]

Hi, I have a 1996 Chevy Suburban as my tv. My truck currently has 252,000 plus on her and I started with the filter alone with 171,000. I kept the original air box with the thought of going all CAI, and I eventually did. I like the sound. I also changed from stock exhaust to Magnaflow exhaust. I love the filter, I have had no problems with MAF sensors or any other issues. With a full CAI (FIPK) I find that the truck exhaust is much noisier while pulling my Overlander. I am not real thrilled with the exhaust volume in the truck while pulling. I think that on my next trip I am going to reinstall the original air box and K&N filter and see what kind of volume I get out of her then.
I have no experience with deseils so I am no help there, Just thought I would give you a heads up on the noise, which I attribute mostly to the Magnaflow exhaust.