Just changed my air filter for a new one, car has covered only 18K but the fuel economy has been going downhill recently.

Amazed at how much crud was in there, filter filthier than an old dyson filter, air box below filter looked like an old flower pot, tons on junk in there.

Cleaned it all out and fitted a new filter, see how things go.

How can SUK rely on 40K changes !!

Pollen filter next, last time I looked that was just as bad.

Yup, I had the same thing with my vRS at 16k. Just fitted a standard filter for

Pollen is at 20k and Air filter at 40k on my Octy TDI. My MPG fell through the floor before the 40k so I cahnged it myself and will be doing so every 10-15k now.

I have no idea how they can claim 40k, because as i have said elsewhere it isn't true and certainly won't be good for the engine. Wonder if this explains some of the clogged turbos you see on the diesels?

EDIT: Oh and at 40k it looks blacker than a black black thing, in a very dark room with some added black.

Having seen what mine was like at 7k, I will be changing mine every ten k from now on. 40k is a pipe dream IMO.

Maybe as the 40k figure is correct & in the handbook etc - i.e. it is specified as 40k.

I wholeheartedly agree though that you ought to change at least twice as often with the paper filter to avoid excessive smoking and cr*p fuel economy.

With a green filter or K&N you'd want to clean it a bit more than that, in the sense of shaking out the crud etc.

After 12k(ish) on the paper filter I replaced mine with a green cotton one and it sure made a difference.

For the price of a paper one changing it every 10k is probably not such a bad idea anyway

just had my first air filter change - at the 40k service. I have noticed the MPG has gone up since I had it done....Think I won't be waiting another 40k for the next one..

Hi

When we do a service on the cars we change the air filter every 20k.

The colour of some of the filters are bad.

So to keep up with the economy we do change them every 20k.

We are getting Pipercross air filters in stock just now too.

These just wash in the sink , let them dry and away you go.

These are made of foam and the trapped dust will not block the air flow as much too.

So thats it dealers I hope you have plenty of air filters in

Sarah

Hi

Replaced mine after 22000 miles and noticed quite a difference. The old one did not look too bad, but the change in throttle response was quite marked.

Chris

I clean my Green filter every 4-5000 miles. I'd change my oil that often to if I could afford it.

Just taken mine out on a proper journey since replacing the filter. Difference is quite noticeable, engine revs far more easily and the MPG on the trip is up, before it was hard to get it to 50MPG on average, M25 today with the traffic and it's over 54, pleased with that! Won't be leaving it so long next time.

I know that the aftermarket filters flow more air and are advertised at blocking 0.5 micron particle size but what happens AFTER you wash them.? Surely that efficiency isn't the same. No matter how gentle you are, you must cause some microscopic damage and 5/10,000mm (0.5 micron) openings must be pretty delicate. And the oiled filters' effect on the MAF?

I remember reading that people in the US used to leave off air filters for street drag racing.:eek: Sure it feels better but what happens to the engine?

I have to replace my air filter because we went through two sandstorms here in the last month and I'm sure that its "loaded" (My american car had a note in the owner's manual advising to change the airfilter after a sandstorm - what?! 4-6x a year?).

At the price of the original paper filter, it's probably cheap insurance to change much more often than 40K. (I don't know that I would trust a high-flow filter in this harsh desert environment, quite honestly.)

As a little experiment, I would love to see what would be the effect of taking off a green filter used for say 10-15K and replacing with a brand new original paper one. :holmes:

I would think that 40K gives an approximation of the amount of air flow that's gone through the filter with "normal driving". Since it's not humanly possible to drive a Furby vRS in any manner resembling normalcy, surely this is not the value to adhere to!

So 40K driving like an old gran :drivesaf: = 10-15K driving like a madman :rally: .........

Cheers,

Bas:thumbup:

Interesting review below....

http://www.mkiv.com/techarticles/filters_test/2/