Different hello and different question :) My car have a custom air filter, sports like, cone shaped instead of original, big, black box with a square filter inside. It is full of dust at the moment and I was told that it is better to have original put back because it will keep filter cleaner for longer and is more quiet etc. instead of this sport filter which stands in the open so all dust and dirt from the engine goes straight in to it. Is it true? Is it worth to change it back to the original? At the moment I have this kind of filter:

http://www.ebay.co.uk/itm/FORD-FOCUS-ESCORT-PUMA-BLUE-CONE-AIR-FILTER-INDUCTION-KIT-GREAT-SOUND-/300620122545?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item45fe5b09b1

Thank you for help in advance, as you understand - I am zero about cars, so all information will be much appreciated :)

Those types of filter will suffer from heat soak in the summer, unless you have a separate cold air feed. I doubt if there is any noticeable performance benefit, and the original air box will make things quieter.

What I do suggest you do, is if you do fit the original box back on, buy the air feed that clips on the back of the grill along the bonnets slam panel for a 2.0 litre automatic. That gives a better air flow to a standard air box than the non automatic version. At the same time fit a K&N panel filter to improve it further.

hi i had a cone airfilter and it lacked at the top end get ur self the original air box and get a k and n patten airfilter you can get them for £25 on ebay

Super, thank you for information, I will definitely buy k&n filter, especially if it really doesn't need to be changed, but just washed out. Thank you for your help :)