[Kolyan2k]

I though there was something strange on charcoal comment..... since its used to neutralize air odors

[ZZZZ]

Originally Posted by Aces

K&N Filters are layered and oiled cotton not paper. K&N does not breathe as well as plain paper filters.

The stock air filter does not have charcoal. The cabin air filter has charcoal.

On top of that when they are freshly cleaned they allow through more dirt not less. Over time the dirt and dust that builds up on them traps smaller particulate matter. You also don't change the filter more often, you don't change it at all, you clean and re-oil a K&N filter.

Way to resurrect a thread to answer a question with total misinformation. Literally everything you said is incorrect except that this is an old thread.

Yes, my mistype it's cotton. I use K&N filters by the way, I wasn't bashing them.

With that said, thank you for the 100% accurate response, especially regarding our intakes not having a charcoal filter. And about the oil in the K&N filters not allowing smaller particles through---even though the independent tests available on the internet say otherwise, it's nice to have a knowledgeable source set the record straight. Much appreciated.

[1QuikWS6]

The stock air filter does not have charcoal. The cabin air filter has charcoal.

I though there was something strange on charcoal comment..... since its used to neutralize air odors

With that said, thank you for the 100% accurate response, especially regarding our intakes not having a charcoal filter

Talk about mis-information

IDK what planet you guys are from, but BMW's DO indeed have a charcoal filter in the intake system. At least on the NA 6's, the charcoal filter is permanently built in to the rear half of the intake & used as an emissions device. It is supposed to catch/contain vapors from the engine returning to the atmosphere when the engine is off. It is there in addition to the removeable filter element and viewed as a flow restriction by many...

Do a search on 'charcoal delete' you'll find where many cut out the charcoal filter with a dremel to get better flow. Here's the DIY:

http://www.e90post.com/forums/showth...harcoal+delete

I just swapped my intake for the Euro Version - which does not use the charcoal filter.

And I have used K&N's for years in all my cars. Never had any problems over oiling and contaminating any MAF's, & all my daily driver cars are driven to at least 150k miles before trade-in with absolutely no engine problems.

[Kolyan2k]

^ so to my understanding thats not even a part of air filers? initial comment was inaccurate because air intake filter does not contain charcoal particles

[Aces]

Oh, I'm sorry I wasn't clear. I was assuming we weren't talking about a filter that requires you to cut it out and that's not changed at regular intervals.

As far as catching smaller particulate matter, I'm not sure I was clear there either. Over time as a filter catches dirt and dust it further closes the pores that allow air and anything else small enough to pass through. Check number two here: http://www.cumminsfiltration.com/htm...g/faq/air.html

When dynoing one of our race cars(SCCA Spec Miata's.) we determined that the K&N filters are more restrictive than cheap paper filtration. The difference was substantial and it was even more so when dealing with a restrictor plate. Keep in mind that I'm not talking about custom K&N intakes, this is strictly with the stock airbox using different elements. We didn't test the cone intake filter as the 1.6l 1991 car can run any filter you'd like and the one that is on it is huge.

I have also run K&N in all of my vehicles, I would rather have a longer life filter than peak flow.

I apologize for being snarky, I had a bad morning yesterday, I should have asked a couple of questions rather than been an ass.