Seems pretty arbitrary. In a dusty area they won't last long at all, clean air country they will last almost forever. What happened to "inspect the filters by shining a light through them".

 

There are a few sides of opinions when it comes to filter replacements. One thing to take note is that dirty environments will clog up a filter quicker

As those types of filters are know for trapping allergens, it stands to reason that some of the allergens might be of the mold-producing variety. Letting the filter sit long enough in a warm, moist environment may cause some issues for some people.

IMHO for both air filters you just have to check them. The intervals are pretty meaningless.

+1 to all of you

It would be pretty difficult for a maintenance schedule to say:
If you live in a dry area and park in a weatherproof garage, change the filter every 14 years.
But if you park outside in the dust, change it every 17th week, unless it rains on the 12th week, then wait until the 18th week.
Those who live in cold urban climates just change it when the filter is stolen.
If the car is parked in a moist tropical area, change it when the insects eat through it, or every three days.

LOL

So customer goes into Quickie-Lube for an oil change, oil change guy comes out and says, "Looks like the cabin air filter is dirty. Do you want me to change it?"

Aww man, I don't think you want Quickie-Lube yankin' on your glove box

https://www.youtube.com/watch?v=gHLs5SwaqEE

 

The whole maintenance schedule is a joke. It's amazing how just about every 2015 vehicle has the exact maintenance schedule and all the mileage / dates are always equal....3 months or 3K miles. 6 months or 6K miles. 12 months or 12K miles. It's silly. The owners manual is pretty shameful as well. Glad I like the Outback a whole lot better than the literature that was supplied with it.

 

There are a few sides of opinions when it comes to filter replacements. One thing to take note is that dirty environments will clog up a filter quicker, for obvious reasons, as noted above. When you change it out is really up to preference and environs. For a comparison, high end filter monitoring equipment/surveys look at the pressure drop over filters to determine the life of said filter more so than the age. But most of those systems utilize synthetic filter membranes to avoid the premature material breakdown point.

That said, there are a few engineering factors that come in to play. One being degradation of the filter media. Over time and exposure to heat, certain filter membranes can breakdown and start to disintegrate. While this would be an annoying factor with the cabin filter, the results would be worse with an engine intake filter. Replacing the filter before this degradation takes place, even though the filter media is not full of debris, would be wise.

 

...Why on earth would 12 months have anything to do with how often an air filter needs replacement?...

As those types of filters are know for trapping allergens, it stands to reason that some of the allergens might be of the mold-producing variety. Letting the filter sit long enough in a warm, moist environment may cause some issues for some people.

Sadly, in this day and age, there are enough people that would have no issues with filing a lawsuit alleging the manufacture new good and well those filters would cause problems but didn't say anything about it.

On a side note, I change out the cabin air filter in my Camry with one of those Filtrete filters that I cut to size. I can get 4 to 6 filters for the price of 1 stock Toyota filter.

 

As those types of filters are know for trapping allergens, it stands to reason that some of the allergens might be of the mold-producing variety. Letting the filter sit long enough in a warm, moist environment may cause some issues for some people.

That sounds like a plausible reason I hadn't considered - probably more of a concern if you live in FL but not so much in New England.

 

It's consumer driven just as much as it's Subaru driven. A large portion of the consumer base is not mechanically inclined, even if they're overtly attracted to schedules and micromanaging maintenance, so simple reductions, one size fits all applications, and frequent maintenance make sense.

 

Ding!
AKA, the manual is formulated from standard deviation.

 

IMHO for both air filters you just have to check them. The intervals are pretty meaningless.
I just had my 2015 Outback 3.6R at just over 20K miles (purchased Jan 2nd) in for an oil change and asked them to check the air filters. Both were pretty bad. I do occasionally drive on dusty forest service roads, and did drive through a short dust storm recently. At 12K miles they didn't need replacing...
Yea a shop that actually doesn't just replace stuff to replace stuff... Kinda like people rotating their tires every X miles regardless of whether they need it or not. You gotta measure the tread depths...

 

It would be pretty difficult for a maintenance schedule to say:
If you live in a dry area and park in a weatherproof garage, change the filter every 14 years.
But if you park outside in the dust, change it every 17th week, unless it rains on the 12th week, then wait until the 18th week.
Those who live in cold urban climates just change it when the filter is stolen.
If the car is parked in a moist tropical area, change it when the insects eat through it, or every three days.

Instead they settle for what works for most people. I think the manual is long enough. Or it was a few hundred pages ago.

 

It would be pretty difficult for a maintenance schedule to say:
If you live in a dry area and park in a weatherproof garage, change the filter every 14 years.
But if you park outside in the dust, change it every 17th week, unless it rains on the 12th week, then wait until the 18th week.
Those who live in cold urban climates just change it when the filter is stolen.
If the car is parked in a moist tropical area, change it when the insects eat through it, or every three days.......

Why Not?? The rest of the manual already reads like that.:grin2:

 

My take, it goes like this:

Manual says: Cabin air filter - inspect and replace as needed.

OK, so how do you define that? Most owners, probably a very high percentage, don't know how to remove the filter anyway. And if they can get get it out, how do they know if it's too dirty? So customer goes into Quickie-Lube for an oil change, oil change guy comes out and says, "Looks like the cabin air filter is dirty. Do you want me to change it?" Customer thinks to himself, "Self, these guys are always trying to pad the bill", and declines. Filter never gets changed.

Manual says: Cabin air filter - replace 12,000 miles (or whenever)
Filter gets changed at interval + 100% / - 0%, but it eventually gets changed.

 

I just check my cabin filter couple weeks ago at 12,000 miles. Compared to a new one I have on hand, it looked like new, other than couple small leaves got stuck to it. My dealer wanted $33 for a replacement cabin filter and $58 installed (for a 30 second job). I bought mine online for $22. I guess it is something to pad the bill when the car is in the dealership shop.

 

They're so cheap I replace mine every oil change myself. I tried the every 12 month thing, once... The filter was so dirty it was growing something on it, ewwww!!!
Thank God the 2015 is easily replaced.
Oh, one more thing. The activated charcoal filters are only more expensive. They do nothing for the smells outside. Just a cheap filter will do the trick.

 

Ah, the cabin air filter - I have to image this is the service adviser's favorite feature on the car. Several Subaru dealerships around here charge between $90 and $120 to change it. The filter itself costs about $2 and it takes less than 2 minutes to swap. Needless to say they put the hard sell on you for it. It's up there with the $69 wiper blades at Acura. One of the reasons I stopped going to dealerships (there are some shady dealers around here, I've had service advisers clearly make up things on the fly, dispute the factory service schedule / tech manual and even get in a yelling match with me with SoA on the phone telling them they're wrong in a fight over a loaner for warranty work).

I pick the low-hanging fruit, maintenance wise, to do myself on my and my wife's car. Air filters, light bulbs, wipers... that sort of thing. I buy a bunch of filters and wipers and bulbs from RockAuto Parts Catalog at a time to save on shipping. These little things save $hundreds vs dealer prices.

I change it based on mileage when I do the engine air filter around every 10k miles or 6 months - they tend to get gunked up by the fall with insects and dead leaves. If you're so inclined you can get charcoal activated filters that are supposed to remove unwanted odors.

 

I find acceptable quality filters on Ebay that are much less expensive than the sube dealer price, and replace at least @ 6 mos. spring/fall.

Also run the system about 95% on recirc, it's the outside air that's dirty.

My dealer proudly wants $85 to change the cabin air filter, forget that!

 

I've had really good luck with Wix Filters, I used them for years in both the engine and cabin in our cars. Here are the part numbers:
2016 3.6R Outback
Cabin - 24483 - $9.76 @ Rock Auto
Engine - 49012 - $8.23 @ Rock Auto

 

I see no reason not to follow the interval.

If you regularly drive through smoggy and/or dusty environments, all the more reason to follow it.


And besides, it's cheap insurance. I don't think our naked human eyes can quite grasp the full extent of what the cabin filter is really catching.

The air you breath inside your vehicle heavily depends upon how effective your cabin filter is.

And as mentioned, those in humid areas should replace it as prescribed too since the high moisture content could promote mold growth in your HVAC system, not something I would want to bother paying someone to crawl in and clean/fix.

 

Kind of funny in a way, cars didn't even have cabin filters 15 years ago (or there abouts). My 03 Audi had one but the 96 Miata doesn't as well as the 87 Tbird. Heck, I even remember when we used to drive with the windows down.

 

... cars didn't even have cabin filters 15 years ago (or there abouts).

Ever see what the A/C evaporator or heater core looks like after a few years of service in a vehicle with no cabin air filter? It's amazing that any air gets through at all.

 

A heads up for the DIY. Maybe it's different now but when I first changed the cabin air filter in my previous 2011 Outback there was an arrow on the factory installed OEM showing which side of the filter should be pointing up. The non OEM aftermarket filter had an arrow showing which way the air flow should go which was the opposite way the arrow was pointing on the OEM - should be pointing down. Maybe it's different on the Gen 5 as I haven't changed it yet.

 

Yep, better to change the cabin, and engine, air filters based on conditions, rather than time.

I always change my engine air filter after a few days spent driving on a beach with fine windblown sand regardless of time in service of the filter before the beach trip.

And I always change my cabin air filter after the oak tree it lives under finally quits dispensing the gazillion pounds of oak pollen and leaves it produces each summer.

I went a couple of months long on this year's cabin filter change. To Subaru's credit, the A/C system was still moving plenty of air on 100 deg +/- days.

In my defense, that couple of months was when my Outback was in/out of two different body shops for collision repair.

No need to empty the glove box, just prop it so the slope of the inner lip is slightly to the right angle to keep stuff from rolling out. And my glove box is fully loaded.