How often do you replace your Air Filter (OEM)?
 

I change my oil and brake fluid annually (about every 3,000 miles). My air filter (OEM paper) is two years old (about 5,000 miles on it). Do you think I need to change it, or should I wait until it has some more miles on it?

Depends what it lookslike - is it dirty? Go ahead and change it not like its an expensive part. It has been 2 years.

According to the Bentley manual for the 3.2 (take a deep breath) - air filter change: 30.000 miles!

Same manual also states engine oil change at 7.500 miles.

I wonder how much extra longevity we really obtain with changing stuff with such short intervals as compared to what Porsche did advice ?

I don´t go by the 'book' neither. Change oil once a year which amounts to around 3000 miles. Brake fluid and air filter every other year. Over precocious ? Brake fluid - No. Oil and air filter - probably.

Just my rookie 0.02 Swedish pesetas.

Change the air filter when you change the oil.

The oil change interval is 7,500 mile or one year. So I think you should change both yearly unless you drive more than 7,500 miles.

What oil do you use with the 7500 mile intervals? Dino or synthetic?

Within reason, I do not believe it matters what sort of oil you use. Aspects like engine age and mileage as well as tendency for leakage, street or track, cold or hot climate - are probably more important for choice of oil. Dino or synth equally.

Mine's a turbo (lots of heat), and I run it on the track in California (even more heat) - I only use synthetic oil.

I don't think a 5,000-mile air filter is dirty, but I do think a brand-new one will flow more air. Since I am tracking it, I think I will replace it.

I run 0w40 synth because of our cold hostile climate. Do what I can to minimize cold start wear.

buy a k&n, oil it and forget about it! they work better dirty than clean. multiple MINT 400 /Parker 400/Baja races thru the silt beds for miles should be enough evidence that they work very well! yes i know none of us drive thru silt beds very often, but if it can protect race cars and trucks and AH-64 apache helos.............its good enough for my piss ant 3.2 liter. plus figure cost of multiple paper elements to buying (1) k & n for life!

Caveat: as with most service intervals there will be a regular and severe service schedule, both for oil and air. If you drive back-country roads a lot you will definitely clog the air filter with the dust kicked up sooner. I always like to hold the filter element up to sunlight and see if I can still see thru it easily ( have a K&N now, but same idea) before replacing. If it stills looks pretty good just make sure you DON"T put it back in BACKWARDS.
Summary: it's not just miles, but the type of miles as well.

Uh oh...here we go.

I would never put a K&N on my car.

I have done extensive research (I am an automotive journalist) on foam/oil filters. They don't filter nearly as well as a paper element. Period.

Race engines (and AH-64 turbines) aren't expected to last 100,000+ miles. With that in mind, particulate wear isn't an issue when you re-build every few months.

funny as of 5 minutes ago K&N ad was run for INDY. described how INDY cars are using K&N's. hmmmmmmmmmmmmm i guess when your shelling out that kind of dough.........and running 10000 RPM's it would be wise to use a paper element. bizarre why they have chosen K&N over ANY other element???? like i had writtian previously, from previous experiences in the silt beds of the mint,parker, gold coasts,bajas on bikes buggies and trucks, i really cant see scientifically how a paper element would even survive! let alone not ingest enough foreign material to lunch your motor. but to each his own. i guess AH-64's in the dezert here in Az, and overseas in iraq and afghanistan, would benefit greatly by using a paper element??????? so why arent they using them?

one additional note regarding filters. take a look at what parker pumpers(off road filtered air to helmet) supplies with their unit. you guessed it ...........K&N!

New thread time: Paper v. K&N
15 rounds, 12oz gloves and no standing 8 count!

Yeah, start a new thread and I will tie up my gloves... :cool:

emission since your close proximity to ensenada. why dont you take a trip there for the upcoming SCORE BAJA 500 and take a look at what air filters are being run at tech inspection. it may be a good topic for an article. since the 500 has the honor and distinction for being the most grueling BAJA race unlike the 1000 which runs more pavement. i think you may be very surprised.

Two identical 144 sq/in filters:

A paper element filters more particulates and flows less air.

A foam/oil filter flows more air, but allows more particulates into the engine.

Prove me wrong.

emission, then please explain to me why AH-64's use them??? please! im sure the pilots want a flame out or other in flight emergency due to particulates. im sure the crew chiefs want to rebuild the turbine all the time. im sure the ground pounders who call in air support want to hear "sorry we cant fly today because of dust!" and best of all im sure the base commander wants to hear that none of his birds can fly due to particulate ingestion and he has a slew of AOG's(aircraft on ground). maybe they run K&N's to just slap a sticky on the side of the fuselage!

why do the vast majority of any off road venue participants, Best in DEZ, SCORE,CORRA,WHIPLASH etc run K&N's? because of the stickys? i doubt that very much. why do million dollar plus trophy trucks w/mega buck unlimited mtrs. run them? why do my friends w/a mega buck Class 1 car run them in the upcoming 500???

we managed to take 2nd overall in the state w/our SCORE 1/2 1600 car. beating class 1's,2's,10's, 8's with a piss ant restrictor plate german 1600 mtr. we ran 7 races, finished all. never did we rebuild motor. all we did was change oil, clean k&n's, adjust valves. PERIOD! and when we did take motor apart..........we had not one iota of wear on any internal part from being sanded. i rest my case. see you at the 500! maybe you should buy a ride for an article, experience a miles long silt bed or the laguna diablo and find out what hanging your ass out in space is all about!

All that said, I bought my BMW 325i with 140,000 miles about 8 yrs ago. Now it has 261,000 miles on it. I have NEVER changed the stock type paper air filter although it had probably been changed sometime before I got it. I use about 1 qt every 3500 miles (halfway between my 7k change interval). The filter still "looks" clean and the car drives perfect. Unless you drive in dusty conditions, stock maintenance free paper filters obviously will last a long time. Filters that require frequent oiling work well also no doubt, but they do need to be cleaned and re-oiled on occasion. I change my airplane's oiled foam filter every year or 100 hrs religously, as over time it will get covered with bugs, grass, dirt etc which blocks the airflow, but my daily driven cars only get a new filter if the filter gets oily and dirty. Just thought I would interject some real world common sense. Filters are relatively cheap, but I take no pleasure in burning money for no reason.