Is a K&N air filter rebad for your truck

My K&N CAI has been on my truck for six years now, no problems so far.

They let way more dirt through. Im a diesel guy and K&N is a big no no...but im sure its not nearly as bad for gassers.

They filter better than your factory paper intake...

If you ever take an old K&N and poor something harsh like gasoline on it you will see it pull all the oil out of the filter and you will see the white filter paper.

HVFC6040 said:

They let way more dirt through. Im a diesel guy and K&N is a big no no...but im sure its not nearly as bad for gassers.

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This is not fact, sorry.

Teh Wicked said:

They filter better than your factory paper intake...

If you ever take an old K&N and poor something harsh like gasoline on it you will see it pull all the oil out of the filter and you will see the white filter paper.

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Not true, your factory paper filter is deffinately a better particulate filter.

GregK said:

This is not fact, sorry.

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Yes it is, let me dig up the flow charts and particulate size/volume charts for you

Common physics tells me, if you have more airflow, you had to increase the size of the hole the air passes through, hence letting more dirt through.

Edit: Here is a crude test, I am still looking for the lab test. http://www.bobistheoilguy.com/airfilter/airtest3.htm

Looking for those studies now...

It's not about making the holes larger, it's about having more small holes. If you used a sheet of printer paper you'd have zero flow, if you perforated it the same as the stock filter you'd have flow and if you had more holes of the same size you'd have more flow again.

"Bob" did not use a validated test procedure way back in 2007. Not to mention K&N filters do not void your new vehicle warranty, how did they get that approval? If the filter is damaging in any way the vehicle manufacturers certainly would not approve the use of it.

K&N have actual test data on their web site as well.

HVFC6040 said:

Not true, your factory paper filter is deffinately a better particulate filter.



Yes it is, let me dig up the flow charts and particulate size/volume charts for you

Common physics tells me, if you have more airflow, you had to increase the size of the hole the air passes through, hence letting more dirt through.

Edit: Here is a crude test, I am still looking for the lab test. Filtration Testing for Amsoil, K&N, Napa, Jackson Racing, Baldwin, and Mazda air filters on a Miata

Looking for those studies now...

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Yes, it wouldn't make sense if they damaged the motor, NOBODY would use them then.

As GregK was saying, If you think about the surface area a big K&N covers, and a stock filter covers, you'd see that the K&N has much more surface area, and thus having more holes in the filter, but still keeping the same if not more dirt out.

Re: Is a K&N air filter really bad for your truck

six shooter said:

I have been reading these fourms and now im starting to think that maybe a should have not put one on my truck last week but i bought the best flow master i could find and wanted a good air filter.

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Run it six shooter. It will NOT hurt the Truck.

I have used a K&N air filter or CAI on every vehicle I have owned since 16yrs old, cars and trucks without a single problem and + results even on a dyno. I just purchased my Titan and the first thing I did was a K&N filter and exhaust letting your engine breathe is a must in my book.

When I sold my last rig, the guy who bought it worked at (his dad owns) an oil analysis lab. They do analysis for big rigs and big machines. He did the oil analysis on my SUV.

I was running a no name CAI that I never cleaned/oiled. After about 7 -10k miles with it on, I was a little worried that this guy wouldn't buy my SUV after he checked the oil. It came out clean.

The guy said most of the time, when they see the aftermarket cone filters, the oil has a ton of dirt in it. It's usually after the person cleans the filter by washing it that they see problems.

you should use it. the only place that it wouldnt be recommended is in a very dusty place, but for any other place go for it