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Discussion Starter · #1 · (Edited)

I had a negative experience with the K&N Air Filter so I thought I would share my finding and to see if it is consistent or different than others who might have tried this product.

I have a 2002 330xi, which has both the performance and sport package. I thought I would try the K&N High Performance Air Filter. I read some decent reviews, so I thought I would give it a try.

The difference that is stated between conventional filters and the K&N product is the material from which they are made. Standard filters are made from pleated paper consisting of compressed fibers. The spaces between these fibers provide microscopic holes the air must pass through which the air passes. The fibers block airborne particles. Over time, the paper filter becomes dirty, and its ability to allow air through to the fuel management system deteriorates. On the other hand; K&N filters use oil-impregnated cotton fibers, rather than paper. The theory is that such a filter will allow more air through, while still effectively trapping dirt particles. The company claims that 50% more air is passed through their filters, compared with equivalent paper products

Anyway…I put in the K&N air filter early this evening and took it for a short drive, and noticed an immediate difference:

- The car did run a little smoother; however;
- I did not notice an improved acceleration, but rather a more sluggish one, and tone of the engine was noticeable quieter

I thought this was just me, so I went back home, had dinner, and decided to take the car out for a test ride again. Only this time, I drove the car with the new K&N filter in for about 15 minutes, pulled in a parking lot and put the original OEM filter back on, and then drove the car back home. With the OEM filter back on I:

- Noticed a big difference in the way my car takes off and rides.
- My nice throaty sound under the hood returned.

Bottom line; I like the way the car sounds and performs with the OEM filter. I did not like the K&N filter and feel I wasted $40 bucks, which could have been spent on better things such as Zaino or tires!

Has anyone else had any experiences with the K&N Filter such as this?


Keeping it surreal
43,351 Posts
Based on past threads regarding K&N,I think the general concensus is that it`s hard to improve on the factory air filter (unless you install a full CAI kit).

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