Did you waste your money on K&N?

[four_by_ken]

No, a diesel needs much more air--in fact,a diesel is like having an open intake with NO carb on it,running wide open all the time,even at idle,it needs 100% of the possible air it can get(and turbo diesels stuff even more down its throat!)--this is why diesels have no vacuum,there are no throttle plates like a carb to restrict the air flow,thats why they need a vacuum pump to run things that normally would use manifold vacuum on a gas motor.....Air filters get dirty REAL fast on diesel,since so much air passes thru in a given amount of time,compared to a gas engine....

Yup, you beat me to it.

Air hogs they are. The more fuel and air you can stuff in the more power you will get.

 

[rjfguitar]

don't carbs need more air than diesels?

It is by far the opposite.

 

[6.2Blazer]

I run a K&N in my 2500HD, not saying they are good or bad but made the decision based on price. A typical Fram air filter was close to $20 and the K&N was just over $40 and should last the life of the truck. Will my engine blow up sooner because of it....we'll find out.

To be perfectly frank, I really doubt anybody is going to see any huge fuel mileage or performance benefits with the K&N, maybe a little if the old filter is overly restrictive or dirty, but nothing major. I find the claim in one of the posts about a dramatic increase in mileage rather suspicious (to be nice.....) as a 20%-30% mileage increase just is not realistic in any way by just dropping in a different filter. There are manufacturers and aftermarket companies that are trying feverishly to just come up with products that improve mileage by a couple percentages. Don't you think every factory vehicle would come with an K&N, or equivalent, if they made that much difference in mileage????

Now back to the so-called test results. My first question would be what the sample size was??? Did they just test one of each of the different filters.......I got that impression. I do automotive testing for a living, including reports similar to the air filter test, and can tell you that testing a single sample of any product will give you questionable results. Especially in regards to the table which shows the percentages that are very close between all of the filters. Test 10 or 20 filters of each type and then show me the average between all of them................

 

[Topdown]

my real world data is this ...


When I was running a supercharger, there was enough performance gain with the K&N that I could actually feel the difference in the seat of my pants and a couple of mpg out of each tank

While running a "performance" engine (350HO 330hp) in my Blazer, there is/was no change in either mpg or performance.

All of that leads me to believe that on an engine that needs and uses high-volumes of air, a filter that moves high volumes of air is the best. On an engine that doesnt... its not needed. I also have to figure that the engine with the supercharger is going to last half as long as my 350 anyway and therefore running a K&N isnt going to shorten the life of the engine by much if any at all.

besides that, if anyone is terribly worried about airflow and whatnot, just get a taller air filter. if you run a 3" paper filter, replace it with a 4" paper filter... its not like most of us are bumping the hood when we close it anyway. That extra inch will allow for more air to pass through the filter (assuming your engine pulls/needs it)

 

[four_by_ken]

I also have to figure that the engine with the supercharger is going to last half as long as my 350 anyway and therefore running a K&N isnt going to shorten the life of the engine by much if any at all.

Not if you built the engine right, and dont go crazy with the boost. Should last just as long.

 

[BadDog]

Good point on the sample size, but being an individual and each filter tested running (IIRC) $1500 (which they did cut him some deal on) the sample size would have to be pretty small. And it's been some time since that was going on, but I seem to recall that he had several of each, three maybe? And seems there were 1 or 2, like the Donaldson(?), that he was having trouble getting. To save on cost to the tester (who worked out the deal for testing), the filters were donated by interested parties on TDP in new and in unopened boxes.

Anyway, that's all I can recall that is relevant to the question you raised. For more info, there is a 20+ page thread in the archives of TDP where all that was discussed in excruciating depth, including sample size relative to statistical accuracy.

But for me, the single most damning point with the test is the refusal of any company (including K&N who suffered SO badly in the test) to cooperate in any way with the testing or to provide contradictory data after the test was done. They completely stone walled on all queries.

As for it "looking clean" on the inside as someone said, you wouldn't likely be able to see the small number of particles inside the filter. Those particles that do make it through are in a relatively fast moving air stream and would not likely settle on the inner surface of the housing either, they will go right down the engine's throat. And what does hit the housing is certainly not enough for it to look "dusty".

Hopefully my last response here, but my DMax is a very significant investment to me. The cost of that upgrade alone (the DMax/Alli) on my tow rig cost me quite a few mods on my truggy, and I want to protect that investment so that it provides as much trouble free service as possible while providing the best performance possible. All I can say is that I'm SO glad I went UNI rather than K&N, but it's still not enough, which is why I'm going back to Delco, and that's in an "air hog" chipped diesel. The dyno results between Delco and foam of any type are consistently near zero even in heavy hitter diesels, so why would anyone pay more money for foam in a gas burner other than appearance or resistance to water contamination? There is just no other reason that is backed by facts. When paper cost is lower, filters better, and provides equal performance, foam makes no sense in most applications.

 

[Burt4x4]

Hmmmm, someone tell me what the super fine dust that gets tru the air filter will do to an engine? It just seams to me the particals that do get tru are so small that the engine wouldn't even skip a beat or be hurt by it??? Eventually it would end up in the oil and trapped in the filter or removed when you do an oil change.??

Someone turn on the light for me, it's dark in here???

 

[Topdown]

heheh, I didnt build the engine... it was in the car when I got it

 

[Burt4x4]

Help Help I can't see...I keep running ito walls my forehead is getting brused. Someone please turn on the light for me

 

[BadDog]

I was waiting for someone with more knowledge and facts/studies to respond, but from what I've read/recall, contaminates entering through the intake are the leading external cause of engine wear and make a huge difference in engine longevity.

And yes, it does wind up in the oil, but a non-bypass filter can only do so much without resulting in excessive back pressure. I believe that anything small enough to get past the air filter is going to be too small for most oil filters. That's why many of the guys trying to maximize longevity in diesels (and some in gas burners) run "bypass filters". These remove much smaller contaminates and also allow oil to last longer between changes (depending on the oil).

Unfortunately, I'm not motivated enough to look up references, perhaps someone else can provide more info...

 

[Burt4x4]

No No that's cool, I don't need a bunch of metrics. I was just thinking out loud here and I value all of you guys opinions. I haven't swapped anything in my Dmax yet so I haven't 'wasted' money yet. Now on my K5 I do have a K&N. Been using one for years now. Well the 454 hasn't gotten fire up yet but I used one on my 350 fer years. I love the cleaning ablity after a Hella dirty/dusty wheeing trip.

I would guess the newer engines may be more needy to keep clean. But the old school engines may have a bit more tolerance. Of coarse I am just babbling at this point so I could be waaaayyy over here on this one. hehehehe

I just didn't think thease tinyass particals could hurt steel engines......hell I don't know...

 

[four_by_ken]

No No that's cool, I don't need a bunch of metrics. I was just thinking out loud here and I value all of you guys opinions. I haven't swapped anything in my Dmax yet so I haven't 'wasted' money yet. Now on my K5 I do have a K&N. Been using one for years now. Well the 454 hasn't gotten fire up yet but I used one on my 350 fer years. I love the cleaning ablity after a Hella dirty/dusty wheeing trip.

I would guess the newer engines may be more needy to keep clean. But the old school engines may have a bit more tolerance. Of coarse I am just babbling at this point so I could be waaaayyy over here on this one. hehehehe

I just didn't think thease tinyass particals could hurt steel engines......hell I don't know...

Older engines need just as much protection as the newer ones.

And me... I would rather pay the $14 or whatever for a nice new paper filter every time I go out. I tried cleaning a K&N once after a bog... I just never felt like I really got it clean. Felt more like I just washed the dirt and mud all over the filter and more into it. Nice to have a spare $14 filter handy on the trip also.

I always have a foam prefilter around the air filter though.

 

[Yukon Jack]

I've never heard someone say, dang, just lost an engine - it was due to the air filter. I just have a hard time believing any air filter that filters as well as all of those tested, is going to be responsible for an engine failure or even a premature death.

 

[Burt4x4]

I hear ya on the swap ina new one deal.

I have , so far, had preety good results cleaning my K&N using their soap and oil. I hold um up the the light too see the heavy dirt spots then let the soap soak a bit.

On the other hand just tossin a filter for a new one is a helluv alot eaiser and less time consuming.
Oh great now I am cornfuzin meself all ovver again... hahhhaaa

I ain't gonna trip too much on thease lil dudes entering the intake..hell it's just money anyway....

 

[Burt4x4]

Ya me neather.....well if anything this post provides choices for all of us when at the parts counter.

 

[four_by_ken]

I ain't gonna trip too much on thease lil dudes entering the intake..hell it's just money anyway....

Thats why I just use a nice new clean air filter all the time.

 

[BadDog]

I've never heard someone say, dang, just lost an engine - it was due to the air filter. I just have a hard time believing any air filter that filters as well as all of those tested, is going to be responsible for an engine failure or even a premature death.

How do you measure premature death and figure out what portion of it was attributed to bad filtration, over-due oil changes, cold starts, whatever? That would be a huge test to get any meaningful data, sort of like medical experiments with control groups and all sorts of statistical complexity.

However, it is not difficult to test and see that particulate ingested through the intake DOES clearly cause measurable wear (taking various things I've read as true here since I don't do this myself). And just on common sense, having all that junk in your oil is abrading the engine surfaces every time it circulates through. Sort of like a lower pressure version of the "water jet" technology used to cut steel plate.

And finally, the ultimate point in my opinion, if better filtration is available at a lower cost with no measurable loss in performance, why is it even a point of discussion? Regardless of how important you feel wear by ingested particulate is to engine longevity, the answer seem absolutely clear. If you need water resistance, run a foam. If you think it looks cool an don't mind the reduced filtering with no other benefit, run foam. If you don't fit in either category, run paper.

On cleaning foam, I couldn't agree more. I *hate* cleaning those things and I also feel like I'm just washing the stuff into and all over the filter. I spend way more effort cleaning than "recommended" and still am not happy. The oil is supposed to keep the dirt trapped, but it still makes me cringe to see all that mess that you CAN'T get out.

Anyone want local a slightly used UNI (about 2k miles) and cleaning kit for a DMAX cheap? (also fits the 8.1 I think?) I'll trade you both for a NIB Delco...

 

[TrcksR4ME]

On cleaning foam, I couldn't agree more. I *hate* cleaning those things and I also feel like I'm just washing the stuff into and all over the filter. I spend way more effort cleaning than "recommended" and still am not happy. The oil is supposed to keep the dirt trapped, but it still makes me cringe to see all that mess that you CAN'T get out.

Never had that problem, always looks great when I'm done cleaning mine, and its been pretty filthy I always spray water from the inside out so that the dirt is push out and not in...not sure if that makes sense...but it always looks new when I am done.

Guess I am not so quick to jump ship on something that has proved to work just fine for me despite all the testing and reports to say it is junk.

 

[BadDog]

Guess I am not so quick to jump ship on something that has proved to work just fine for me despite all the testing and reports to say it is junk.

But that's just it. We are not able to individually determine the effects on stuff like this based on simple observation and experience. What exactly is "proved to work"? Just that you've run it and the engine didn't quickly expire in some way directly attributable to the filter? If your engine starts burning oil (or bearings wash out, or low oil pressure, or whatever) after 10k - 60k, is it bad filtration, improper hone/polish, over rev, what? Even if it ran K&N all its life and starts giving problems at 90k, would it have made it to 120k with a Delco? These are not things we can reasonably determine, so we are left with depending on advertising hype or tests like these.

Again, all other things being equal (which they appear to be by any objective reasoning), I'll go with clinically proven better filtration over "looks like it should work better" (after all, I'm not a "ricer" ) and "I can't see any catastrophic failure that I can directly attribute to filtration deficiency" any day.

[Edit]
What I really don't understand is all the people who doggedly hold on to a belief in the benefits of something when all objective information indicates the opposite. But then again, apparently some people still believe the earth is flat... Don't take this in any way personally, I totally support your right to disagree on any grounds what-so-ever and do as you please. But look back through this thread. If I'm not mistaken, every single "fact" (as much as anything you find published can be taken as fact) and test mentioned or referenced has been supporting paper elements as superior to foam in every way except water resistance and limited value for SUPER heavy breathers (which I doubt any engine on this board qualifies as). Where are the articles and dyno sheets supporting K&N? Where are the references to studies that air filter particulate bypass are NOT damaging (or even that the obvious answer may be counter-intuitive). It pretty much comes down to a few "seat of the pants" dyno reports, a MPG claim or two that seem well beyond the limits of reason for what might be gained from an air filter, and some "I haven't ever seen a problem that could be definitively pinned on insufficient filtration" statements. Not exactly convincing in my book, certainly not enough to make me hold onto my (IMO) mistaken choice of UNI for my 2500HD. There are MUCH better arguments supporting Ford as building a much better truck than Chevy, but how many people here would switch to Ford based on those more concrete reasons? So, why would anyone choose foam over paper based on MUCH weaker evidence?

 

[sled_dog]

all I know is my 95 Chevy came with a K&N kit on it. When I removed it just to check it out, I could see little holes in the thing. Could easily get grains of sand though those holes I'd think. I don't like the idea of a Filter that sand could get through.