NavZ said:
The K&N filter has been debated to death, BMW performance part basically rebrands the K&N filter and sells it to their customers. Get one now & clean it regularly/correctly and you won't have a problem.
Wrong. I took my BMW performance intake apart and it does in fact use a paper filter.
The gain from fitting an oiled "performance" replacement filter is no more than just fitting a clean OEM filter, and on an e46 the OEM filter (from the dealers) works out cheaper than performance filters (even in the long run).
If anyone really thinks that they can get more power out of a e46 by changing the filter medium they are kidding themselves, a
s the filter used on the whole e46 range is the same, including the M3, so I doubt the filter that can allow for enough air flow to not restrict the performance of the S54 will have much of an effect on the performance of an M54.