How often do you change the airfilter??

[Patman]

I've never really stuck to a set schedule with any car I've owned, but I definitely lean towards the side of not doing them all that often, as I believe the longer they are in there the better they filter the dirt. With my Corvette, it's got an oiled cotton gauze filter similar to the K&N that came with the Vararam intake I had installed back in December 2005. I've never touched that filter since, and it now has over 69,000 miles on it! It's a bit of a bear to remove and replace the air filter on these intakes, which is why I've just left it alone and figured that as long as I'm still getting good gas mileage and still seeing low silicon in my UOAs, then all is well!

With my new (to me) 2006 Civic, I bought an air filter for it today, figuring that it might have needed one, but I wish I had opened the air box first, because the air filter that's in there now looks like it was just changed right before I bought the car. Oh well, the new one (Fram) was only $12, and I'll have it for the next time I change it (which I probably won't bother for another 50,000 km or so I figure)

 

[1 SX]

Every 3K miles or so, i will take the filter out, and hit it clean.. Takes all of 5 secs..

 

[SS1970chrysler]

I change them when I first buy a car, then just about never afterwards. Most of my cars only get 100 miles or so per year and the 2 drivers have K&N so I just clean them.

 

[MetalSlug]

I just nice enought to change my dad air filter with wix without let him know, 2 month later, at the oil change place they charge my dad for new air filter, I was so mad. anyway I do change it every 2-3 year.

 

[SmokeEater2]

No set time frame,Just whenever they're dirty. I changed both vehicles filters Sunday,Both had close to 15K since the last change.

 

[calvin1]

Never, I clap out the bigger stuff anytime I need to pull the airbox for other work but that's about it.

 

[Jim Allen]

I change it when my airfilter restriction indicator reaches 2.5 kPa over the new reading... and even that's being overcautious.

 

[Virtuoso]

While doing some work on the 'bu last week, I pulled the Napa Gold filter out to give it a once-over since I installed it 25k miles ago. Looks great! "Shook" some bugs out, and re-installed. I'll check it again at 50,000 and see how it's doing.

 

[R2d2]

Under warranty for the Honda, so 15K miles.

 

[PandaBear]

about every 30k

 

[Andyge]

12,000 Miles or 6 MO.

 

[Patman]

Originally Posted By: Andyge
12,000 Miles or 6 MO.


Does it even look dirty at such a short interval? My air filters have usually looked brand new even after twice that mileage/time.

 

[Jim Allen]

Originally Posted By: Andyge
12,000 Miles or 6 MO.


Unless you live in the Sahara, there's probably at least 5 years and 50,000 miles left in that filter. If I had something that it would fit, I'd ask you to send them to me rather than to toss them.

There is no advantage to changing a filter that often, unless operating conditions (e.g. a dirty environment) dictate it. I suggest you do further reading, both here at BITOG and here : Air Fitler, Fuel Economy and Power

Filter efficiency actually improves as it loads up, so the filter gets a little better with age. Fuel economy isn't effected ( in EFI engines and not all that much in carbureted) until the filter is very much plugged and then (in EFI engines) only a little because the EFI system continues to trim fuel right till the end. WOT power will start dropping off as airflow is restricted but that won't happen until the filter uses up all the excess flow capacity that's built into the filter to account for a dirt load. The industry average of that excess capacity is supposed to be in the 30-40 percent range but it will likely vary a lot. In normal tooling around, you may not feel any loss of power, even with a very plugged filter.

So the question is... why change filters so often?

 

[ledslinger]

My brother had to do some minor disassembly to put a battery charger connector on his 600 Yamaha with 3750 miles on it. He decided just for kicks to look at his air filter. It was covered in globs of house insulation thanks to mice. It looked like cotton candy. Haven't heard if it affected how it runs yet. He thought it would run dramatically different, I said unless there was a bunch of paper with the insulation the mice just installed a prefilter, the computer would adjust accordingly.

 

[widman]

Summing up this discussion, if people would just invest the $20 in a restriction gauge, most people who commented would save $40 to $100 a year for the life of their cars, and the cars would last longer for having more efficient filtration.

The negative: Jiffy Lube, FLAPS, and Walmart would have less sales, imports from China, Mexico and Indonesia would go down.

The life of the filter is so dependent on smog, dust, combustion efficiency, and other factors, and the human eye has no idea how to determine a dirty filter by site unless it is filled with debris.

 

[johnsmellsalot]

I replace mine 15,000 or when it gets dirty. Whichever comes first.

 

[The Critic]

On the Altima, the filter was extremely dirty after 9k.

On the Prius, the filter looks brand new-- not a spec of dirt on it-- after nearly 14k.

Not sure about the van...I should probably check it.

Usually I replace the engine and cabin filters every 15k on vehicles I service.

 

[Need4racin]

every 30k miles on a motorcraft filter. Fuel filter gets replaced at the same time. I usually order them off rockauto.

 

[hattaresguy]

On my Silverado just about never, it just doesn't seem to get dirty.