[mobilejo]

If the K&N needs cleaning as often as the OEM paper one needs changing, then what's the benefit - just the fact that its cheaper than buying new paper filters? Or are we all claiming a performance benefit?

[dave-the-rave]

my pipercross filter is coming tomorrow/weds. will let you know how it is

[m1bjr]

Originally Posted by mobilejo

If the K&N needs cleaning as often as the OEM paper one needs changing, then what's the benefit - just the fact that its cheaper than buying new paper filters? Or are we all claiming a performance benefit?

Its hardly cheaper.

Paper maybe what, £20 each?
How often do you change the oem paper filter?

K&N how much?
Plus cost of cleaner and filter and time to do it every 10k?

[335i E92]

If you don't clean a paper filter it just gets clogged but still retains it's filtering qualities so you lose power but remain safe I guess.

Granted if you were to use the K&N or any oil based performance filter without 'proper' maintenance then it'll lose it's filtration qualities and your asking for trouble.

I just find the paper ones too restrictive and the dual cone option a bit OTT an unnecessary, so far the K&N has worked a treat for me for over 30k now.

[magic77]

I went down the route of pipercross as I can clean it and I do regularly 10000miles it gets a full wash and on regular basic I remove it and hoover it out and give it a light reoil.

Paper ones just clog up and cause problems I find it less wastefull then say chancing paper one every 10k or less plus in long run works out cheaper while in case of my e46 it was a must as otherwise I would leave clouds of smoke. Likewise have been using K&N , Piercross and Cotton Green for many years and never had issue. But then been very strict at maintenaces and how I oiled them and always had good results

Back in VAG days even logged stats when testing some new ones for a reseller

PRice wise my pipercross set me back £30. Paper ones go around £15 on ebay. Considering I'm on 40K now I'm quids in

[335i E92]

With a tune I noticed a big difference when changing from paper to the K&N. The the car was much more responsive and stronger through the revs, the paper one in my opinion is too restrictive.

For me it's not a cost issue of paper v oiled. It was 100% the improved characteristics of the car.

In terms of maintenance, taking 1/2 hour of my sat morning once every 10 months is fine by me. Who do doesn't like havin a brew n a quick tinker under the bonnet every now n then.

[m1bjr]

Makes you wonder.

Why the M3 and M5 has a paper filter.

[magic77]

and why nearly every race car you see out there runs K&N or similar. Each to their own.

Also lambos use K&N looking filters as OEM

[Triggster]

Originally Posted by magic77

I agree it depends on cars though as you get to high performance it has bount to make difference. I've just got some logging gadgets for the e90 so might do few tests. Certainly on diesels with a filter I found they produce far less smoke when on heavy acceleartion. Now since smoke means overfuel or lack of burn the filter must be adding more air to help a cleaner fuller burn.

Will need to test when I get time

Bit of a bump.


By any chance did you ever get to test this?

[magic77]

I've got the diag tools but just havent had a chance to find a road where I can run it.

Planning a RR sessions soon when funds allow it. Certainly on past experience on my e46 it did make a difference as mentioned without one I just got clouds of smoke

[jasonmav]

I dont think there is much in it between the 2 types. The best thing in my opinion was the sound of an induction kit. My old E36 with a pipercross viper sounded amazing. I sometimes wonder if I would get that sound on my E90 320D?