K&N filter Yes/No

[chilli76]

Is it worth switching to a K&N filter on my 2005 A4 B7 2.0tdi?

[Guest 2]

not really on a diesel. you'd be better off with a new oe replacement.

[chilli76]

Thanks Chris I won't bother then, just stick with re-mapping..

[szladob]

not really on a diesel. you'd be better off with a new oe replacement.

I have one, but didn't seem to make much of a change, so I think you are correct - any specific reason why they don't perform better on a diesel? I don't remember seeing it as such when I was researching it..

[Gazwould]

Air filter box is of a good size thus no restriction .

[Rob69]

Diesels already run lean with excess air, so a k&n would not do anything extra for the engine. Thats what the egr does, to control and reduce the excess oxygen in the combustion cycle and resultant nox. Whereas a naturally aspirated, throttled, petrol engine might benefit from a free flowing filter. Or so the mkII escort and nova boys back at tech college would say.

[Advanced-Tuning]

from our dyno testing the differene is negligable, but they do last a long time and its a filter for life ;)