Do K&N air filters result in increased emissions

slade_x

I was just looking at the site:
http://www.knfilters.com/filtercharger.htm

and read

Emissions Legal in all 50 US States.

Or is there just a belief that they can and so they state the above?

cyborg

a clean air filter will not harm emissions, be it k&n or other

slade_x

so where does the logic in stating that come in to play

obviously overall engine management like better fuel to air ratios to result in the maximum amount of burnt hydrocarbons are the determining factors of how much pollutants your engine will produce /and how good your cat is at breaking them down

I was only looking into air filters as i was recently just advised to get an after market performance air filter / or maybe it was an induction kit he ment (of which i would not bother with), i cant be sure what they were on about but they seemed to indicate that better airflow would reduce my emissions

I found it odd that K&N would feel the need to state anything about emissions in their product since its an air filter.

I merely expressed concern that when my car is next due for an nct (in december 2011) it may fail as i was told at the last time of testing it just about passed on emissions, this was just back in december 2009, its a Jap imported Celica GTS (new body vvtli)

Esel

K&N are simply stating that their products are legal, not that they reduce (or increase) emissions....

Matt Simis

slade_x wrote: »

so where does the logic in stating that come in to play

snip

I found it odd that K&N would feel the need to state anything about emissions in their product since its an air filter.

Hehe, I like that you question such a thing, but you needed worry about that specific issue in this case for two reasons:

a) K&N have to state that by Law in the US, any "engine" part, no matter how simple, has to pass State Emission laws. They have vastly stricter emission laws and testing then here (think drive by testing, get letter in post 2wks later stating you were detected as failed on X date).
b) K&Ns "thing" is similar to a Dyson vacuum cleaner. Both claim increased airflow with no loss of suction over time. The reality is they both loose suction but in a different manner to the tradional parts (Dyson gets full, filter blocked etc, K&N needs cleaning periodically with their cleaner solution). K&N Filters are reusable with minimal loss of airflow and a offer a minimal, consistant, airflow boost over paper filters.
Basically the minimal extra flow they offer is before your MAF, as long as you car calculates it and compensates, then you cannot have an emission problem.

Previously I had linked to the JCB Airflow meter tests (google it) which showed K&N letting in a huge amount of contaminants into the engine along with the increased airflow, but on further consideration this isnt much of a concern in Ireland, we dont have much dust and dry weather stretches are fairly rare. Wet ground = no dust and in wet environments OE spec Paper filters perform worse than K&N and Foam filters.


PS: Your car may very well fail if it nearly failed last time, thats something you should look into aside from the filter question.