as chrios says, yes, about 50k miles or so, doesnt hurt to do them early tho. when appling oil (can be bought pretty cheap, even from halfrauds) be very careful to apply as littl...e as possible, too much and you will risk killing the MAF sensor (£140+ for new one)
aaaargghh k&n's suck..prehistoric american muscle car junk...oiled elements went out with the arc.
oil mist is released from the filter throughout its whole life which slooowly coats the maf. there are tonnes of better filters for this engine out there..
Does the oil also act as a further barrier to reduce the debris/dust that can enter the engine?
Im pretty sure the oiling process is vital to ensuring it full efficiency. To be honest i cant really comment, as i tend to replace them before ive done 50k anyway. lol. In fact i dont think ive driven a single car 50k before selling it on! :lol:
You can get a cleaning kit to clean the filter element, then re-oil, but do not over oil. No damage will be caused to the AFM unless you significnatly over oil. I've had a K&N fitted to my GTV for over a year and have had no problems. You do need to oil them though, as it attacts and captures dust.
There was some Jap-car magazine I was reading in the dentists once - they compared various types of filters, and the K&N came out top.
i have no affiliation with this company, but i used to work in filtration technology and the company who make the filter material for the amsoil filters are world leaders in nanofibre technology. i also used to tune VAG tdi's and the yanks are streets ahead (as usual) they ditched using k and n's a long time ago, its almost a swear word to them because of the way they kill sensitive air flow components such as mafs.
anyway..they use these, im gonna get one when i work out how to fabricate (or where to get one fabricated) an induction inlet..https://www.amsoil.com/storefront/eaau.aspx