had alook at my air filter today and its as black as fire back.having done 37k the filter is due for first change at 40k.any thoughts on if if it would be beneficial to swap at earlier intervals.

perhaps the question should be
"do you think your car would benefit from a clean filter, or do you think it works better with a dirty one"

how often do you change yours.

mine runs through an induction kit !
so is open to the elements, but is changed before it is noticeably dirty

Sure mine was changed at 20k on my previous IS250 ( along with brake fluid ), think it may be inspect and change if neccesary - have a look at the service book.

no mention of that,service book says change at 4 years or 40k.

I think it is too long, specially for turbo engine which sucks so much of air.
I will replace it now (20k)

let us know if there is any improvement after you change.

Definately now! Didn't realise the service guide was 40k, thats ludicrous! I'll be replacing mine as it obviously wont have been done at the 20k service. Probably go with the jetex, just had a look at their catalouge.

http://www.jetex.co.uk/website/filter_choo...id=1&mod=IS

I will, but "now" means in about 2 months

what do you expect from it? Will it increase the induction noise?

Do you think it will comply with the warranty?

Never had trouble before with these. TBH it is something I usually change straight away when I buy a new car but haven't this time. I don't use them as a performance upgrade rather a long life filter with better quality and filtration.