jeffc2731

Porsche recommends replacing air filters (and cabin filter) every 4y or 40k miles (997.2). My car is always garaged and driven at least once a week, but the miles just don't add up -- around 3k per year. The filter elements aren't even that dirty so I'm wondering if it's really necessary to replace them. Filters aren't expensive and easy to change out but was curious...

rileyracing1

Hard to say depending on your climate and local environment ie. Dusty etc ... Just pull it out and have a look ... Mine was in for two years and it looked great so I gave it a wack and a quick vac and I will replace it in another two yrs as I do about the same amount of miles as you do.

okbarnett

I clean mine out every 3 or 4 months.

sandwedge

I'm in the same boat as you. Down to around 2,500 miles a year now. Last time I replaced all the filters (engine and cabin) they all looked brand new. So you saved me some time asking the same question. With few miles driven, why replace filters that really haven't filtered much? I have a hard time understanding how the ability to filter as designed degrades with age regardless of miles driven.

Petza914

I clean and reoil my K&Ns about every 15k miles or if I see an uptick in silicon in my UOA report, which turns out to be every 2-3 years with the miles the 997s see these days. In my 928 DD probably once a year.

This is the same interval I'd replace the paper element at.

Bruce In Philly

2009 C2S 186K miles

Here is a video of my dirty engine filters after 20K miles of use. I was driving my car into nature reserves and woodlands doing photography and the dirt/sand roads were horribly dusty. At slow speeds, our cars suck the dirty air in... just awful. So, IMO, if you flick your filters and see dust come out, then change them. Otherwise don't bother. Even with these filthy filters, I could perceive no performance changes after I replaced them.

I keep going into these filthy environs so I made foam inserts as pre-filters... and they work!

So direct to your question, save your money. You are in no way needing a filter change.

Peace
Bruce in Philly (now Atlanta)

My foam pre-filters:





New vs dirty filter:




What a dirty filters really looks like:

ADias

Paper OEM filters changed every 4 years or earlier if dirty.

jeffc2731

Thanks for the responses. I agree there's no need to replace them if they're still clean.

ADias

Matter of degree on how much dirt is in there. HVAC systems are replaced routinely and often they do not look too dirty; but replacing them makes a difference.