K&N is a great mod if you are in a desert sand climate. Have run them for years. You will get no performance seat of the pants feel from them. Nice to clean them in a desert envirmonent as the sand and bugs dirty the filter. With the stock BMW air box, keeps alot of the junk out. Unless you have a aftermarket cold air intake.....will not make any difference from a Fram or other filter. If you over oil the K&N or other oil based filter....MAF problems.....check engine light. Just my 2 cents. With a stock air box....it is pointless, if you get a CAI........most of them are pointless without a heat shield and way overpriced for the HP per $$$$ ratio.....you do not need any of it. Again, just my 2 cents.![[;)]](/images/smilies/wink.png "Wink [;)]")