Do Performance Air Filters Actually Work?

[ShinerBock]

I know this has been beat to death here with most people stating that they don't add any horsepower without any dyno data to back it up.

Well Jason Fenske from Engineering Explained decided decided to see for himself instead just regurgitating what he heard from the internet, what a friend's brother's cousin told him, or what a salesman tried to sell him on.

Do Performance Air Filters Actually Work?

If anyone have dyno test refuting this then I would love to see it.

[ib516]

OK, strictly speaking of performance, I recall a test done by a diesel magazine a while back on an otherwise stock 2004.5 Dodge Ram 5.9L Cummins powered 2500. They tried K&N, and about 5 ot 6 other aftermarket intake systems, not just filters. Compared to the stock set up, all were all within 2hp of each other, and certainly within the error range of the dyno. Some even lost the 2hp when compared to stock. Certainly not worth the $500 or so these companies want for "cold air intake" systems - which 99% of new vehicles already come equipped with. Some aftermarket junk sucks in more hot air than anything and they can be very poorly designed.

If you want more power, you'd be far better off buying a programmer for that $500. Those actually make a measurable, repeatable, actual increase.

Here's an interesting article, particularly the comment added at the very bottom. TEST

[ShinerBock]

carringb wrote:

Big Katuna wrote:
Only at WOT.

Ok. But if you aren't at WOT, and you need more power, wouldn't you just apply more throttle anyways?

I don't think he is basing that on any real data especially since the dyno in the video proves him wrong. Just a biased objective opinion.

[carringb]

Big Katuna wrote:
Only at WOT.

Ok. But if you aren't at WOT, and you need more power, wouldn't you just apply more throttle anyways?

[ShinerBock]

Bedlam wrote:
I don't have any metrics showing the decreased life of a street vehicle engine, but I do have experience with off-road toys riding in areas with volcanic ash or mine tailings. Those that have used KN filters, have definitely seen abnormal engine wear resulting in loss of compression, compression blow by and burning of oil. We use a two stage oiled foam filter with a prefilter dry sock over the top and still clean the filter every one or two days. My 10 year old toy engine still has strong compression and does not burn oil.

Yeah, for that application I would not use an oil bath only filter such as a K&N unless I was tearing down the engine on a regular basis.

[ShinerBock]

BigToe wrote:

ShinerBock wrote:
Thank you TnP and rhagfo for staying on topic about if aftermarket filters actually work to increase performance, and NOT about filtration efficiency and/or warranty.

How is "performance" defined?

Especially in an RV towing application?

Is "performance" defined by a 0-60 time?

A rip roaring session on a dyno?

How long it takes to crest a grade?

A 1/4 mile drag strip run?

Or how reliably the tow vehicle can drag the trailer to a camping destination, and return back home again without incident?

What parameters truly define good performance and poor performance in a tow vehicle?

Considering the main duty of a tow vehicle, can the basic task of intake air filtration, to protect the engine so that it can return home rather than leave one stranded in a motel awaiting engine repairs, be completely excluded from towing "performance"?

I think it is pretty clear what is defined as "increase performance" in this thread especially if you watch the video in the link. Not sure where the disconnect is.

[BigToe]

ShinerBock wrote:
Thank you TnP and rhagfo for staying on topic about if aftermarket filters actually work to increase performance, and NOT about filtration efficiency and/or warranty.

How is "performance" defined?

Especially in an RV towing application?

Is "performance" defined by a 0-60 time?

A rip roaring session on a dyno?

How long it takes to crest a grade?

A 1/4 mile drag strip run?

Or how reliably the tow vehicle can drag the trailer to a camping destination, and return back home again without incident?

What parameters truly define good performance and poor performance in a tow vehicle?

Considering the main duty of a tow vehicle, can the basic task of intake air filtration, to protect the engine so that it can return home rather than leave one stranded in a motel awaiting engine repairs, be completely excluded from towing "performance"?

[wilber1]

I had an AFE on my last truck and it worked OK. However the only increase I noticed was intake noise. Might have helped lower EGT a bit over the stock filter.

[Bedlam]

I don't have any metrics showing the decreased life of a street vehicle engine, but I do have experience with off-road toys riding in areas with volcanic ash or mine tailings. Those that have used KN filters, have definitely seen abnormal engine wear resulting in loss of compression, compression blow by and burning of oil. We use a two stage oiled foam filter with a prefilter dry sock over the top and still clean the filter every one or two days. My 10 year old toy engine still has strong compression and does not burn oil.

[colliehauler]

mtofell1 wrote:
Snake oil IMO. Little or no gain, potential damage, potential warranty issues plus the cost of buying the thing. No thanks.

My opinion as well.

[ShinerBock]

Just to be clear, this is about all aftermarket performance filters. While a K&N was used in the video along with another aftermarket filter, this is not just about K&N filters. There are many aftermarket performance filters out there. Some use oil in their media while others use an oil free filter media. There even some that use a paper and/or synthetic media that is used by the OE's but with greater filter surface area.

So the question of the video was if they actually increase power. As was stated in the video, it is NOT about the filtration efficiency, if they void warranty, or if you do not want to risk using them. Although if anyone does have data showing how much engine life is decreased by using one of these filters then I would love to see it.

[theoldwizard1]

What was not covered was real world usage OVER TIME !

Oiled gauze (like K&N) really are good filters, but THEY GET CLOGGED MUCH QUICKER ! Which means they need to be serviced MUCH MORE OFTEN. If you do not service them, they will have a SIGNIFICANT NEGATIVE AFFECT ON YOU FUEL ECONOMY ! Also, you need to clean the intake tube every time from just after your K&N up to and including cleaning the mass air flow sensor (if you have one).

All of this is much worse, if you live in dusty conditions.

Auto maker used to use oiled gauze filters in the 50s and 60s but stopped because people were not servicing them and the paper filters were so quick and easy to change.

Save money and hassle. Just replace you paper filer more often.

[p220sigman]

I don't know if they are better or not, but I wouldn't take the chance for what little gain, if any there is. Honestly, with the power today's trucks make in bone stock form, I'm fairly certain I wouldn't be able to tell if one was making 5 more HP.

[Big_Katuna]

Products like K&N filters appeal to people that like to point and say “Look what I bought, I’m cool!”.

Yeti coolers, under frame lights and hitch testicles come to mind.

[ShinerBock]

ib516 wrote:
I'll tell you about my experience with K&N on my 2002 Diesel. It was properly maintained, and left not only dust in the intake tubing after the filter, but also a very fine layer of dark gunk that I can only presume was filter oil mist and dust combined on the leading edge of the turbo impeller blades which I had to remove.

It went on the local classifieds along with the cleaning kit (oil and soap spray) and I will not use a K&N ever again in any vehicle I own. I don't care if it makes 2 more hp or not. The performance gain (if any) isn't worth the decreased filtering performance (gas and diesel), risk of MAF contamination (gas), or possibly causing an unbalanced turbo that increases shaft/bushing wear (diesel).

Although this is about performance and not filtration.

My stock OE filter on my 99 3500, F150's, BMW's, and current 14 2500 all did the same. I always stuck a rag in the intake box piping after the filter and there was always a fine layer of dust in there. All stock intakes (aside from the first F150) had the intakes replaced and went well over 100k(the diesels over 200k) miles without any oil consumption issues which is the first sign of engine wear from dirt.

Regarding oil on the the compressor blades, you are going to get that regardless since the oil CCV is vented directly into the turbo on a Cummins.

Does anyone have any data showing how much engine life is lost due to the amount of dust gets by aftermarket filters so I can get an idea? Is it 1k miles, 10k miles, or even 100k miles lost using an aftermarket filter versus stock?

[SidecarFlip]

My only comment is, if you run a K&N on a MAF equipped engine be very careful about oiling it. The filter oil in the intake air stream can foul the MAF sensor and cause the engine to not attain fuel trim.