[JT58]

There are so many threads on so many forums about K & N. Some people rave about them, others complain and there is the over oiling issue, screwing up air flow meters, etc.

I can only comment on my own personal experience after many years of driving and using them.

I think that they work. Performance gains- depends on the car and the air filter you had previously. Some OEM filters are pretty darn good quality. If you have a plan paper filter, the K & N is an upgrade. More than performance increase, I have seen a 1-3 MPG improvement. Again it depends on the car and filter, how dirty it was previously, etc.

And you cannot over oil them- it's so easy to wash them and just keep spraying them with oil- just follow the directions and do not over oil.