Changing Your Cabin Air Filter: Why the hell so?

 

Hey! Sports Fans! It’s been a while since the last post and today I have an exciting service to review – installing a cabin air filter in a 2024-2026 Subaru Impreza!

I mean, what could get more exciting?

Cabin Air Filter: Do I Really Need It?

No.

The idea of an air filter for a car is a bit silly, really. There are probably plenty of entry points for air other than the ventilation system, especially if you open the windows or sunroof, thus making the need for a cabin air filter pointless.

In 1989, Mercedes (of course!), introduced the cabin air filter in a response to… Wait for it! More profits.

The off-cited reason of the decrease of air quality and increase in pollution are not resolved by this system. It may reduce pollen and dust, but as it cannot be a totally closed system, and from the two vehicles I have owned, the filter and housing system does not offer an assured seal.

By 1990, the Opel Astra, a mass market car, had introduced the cabin air filter.

So, Hans Freudenburg, in a bid to prevent dust getting on his clothes while he drove, developed the idea of the cabin air filter. That must have been one hell of a long drive or one motherfracking dusty road. Was he commuting on the Dawson Highway?

Anyways, my 2013 Hyundai Accent was the first car I owned that had a cabin air filter. I never changed that filter until I had but 300,000 kms before I changed it. I really should have changed it sooner, but do you need to change it as frequently as the recommended service interval?

In the case of my Hyundai, the long time before the change found that filter had distorted and was not sitting in the housing properly, negating any filtration effects. I have no idea of how long the filter had not been doing its job, but it was a lesson in considering making changes of the filter to keep the car in good shape. I mean, you change the oil and filter but leave other items that degrade and if you have any pride in ownership, you think an owner would at least put a good filter in, or remove it altogether if you think having a cabin air filter is pointless.

Though I question the real utility of a cabin air filter, is now a part of the car’s maintenance regime and an understanding of this part and its place in the service life of your Impreza.

As to profits…

Google the OEM part number and you will find a PLETHORA of 3^rd-party providers offering solutions at a wide range of price offerings. Some are basic filters and some offer, I don’t know, protection from Anthrax or Nuclear fallout.

It’s a filter, damn it. Its primary role is to prevent PARTICULATE intrusion into the car’s cabin. It is a paper accordion pleat with a paper frame. Probably about 0.32 cents manufacturing cost. $1.01 landed cost in Canada in its box. These aren’t real numbers, but I am sure the profit margin on this part is ginormous.

Changing Your Filter

Below are the instruction for the current body style of the Impreza (2024-2026). Other Imprezas are probably similar, but CHECK your manual for correct procedures and fitment.

Replaced with FRAM CF12157 (est. $25.00 to $39.00 CDN).

 

 

Condition of Removed Filter

 

Why Change Your Filter?

It was evident from changing out the original filter it was picking up debris. Was this debris, if it passed unfiltered into the passenger cabin? Probably not, but it does prevent contamination of the ducting and fan, and that does keep the efficiency of the HVAC system intact during the life of the car.

Seriously, if you drive with your window(s) open, you are fully defeating the purpose of the filter.

Plus, for those with OCD, changing stuff related to your car’s care will be a soothing balm as each item gets done.

Do you need to change it as regularly as Subaru recommends?

Depends, Sports Fans. If you live and drive in a dusty climate or desert area, I would do the first change at the recommended interval and then amend the frequency of the changes. You could check the filter at intervals, but I think the effort outweighs the result. Plus, if you are not careful, you could introduce containments into the fan and ducting.

I would not leave it for more than 2 years, regardless of mileage, as it may start to warp and deform in the housing, preventing it from doing the job it was indented for.

Definitely do it yourself, and save some money, and learn a bit more about you car.

What Does Subaru Say?

Subaru recommends replacing your cabin air filter every 12,000 miles / 20,000 kms.

As this is a recommendation, your mileage/kilometerage may vary. If you drive on dusty road regularly, you might consider a more regular maintenance interval.

The OEM part number is 72880FN00A and its price is $30.00 USD MSRP.

There are plenty of 3^rd-party providers with Fram being one of the more recognizable brands.

Conclusion

So, a bit of contradictory information...

I think car cabin filters in most North American environments are silly. They are another high margin part that fixes a problem that does not really exist.

However, with my last car, I totally neglected the filter, and paid for it with fan noise, which potentially could have led to fan damage or failure.

My goal is to change the filter at an interval that is double that of the recommendation, and to source a filter of reasonable cost.

So, Sports Fans, take these wizened words into consideration when you consider doing a filter change.

Remember to keep the rubber on the right side of your vehicle. Drive safely and practice the Subaru Salute.

Engine Cover Install on 2024 Impreza RS: The Red Mist gets an engine bay upgrade!

 Good day Sports Fans!

Today we will gussy up the Red Mist's engine bay. As you can see it is a bit pedestrian with the intake manifold and associated hardware exposed like some Steam Punk art exbisition. The engine is left to be exposed, and even entry level Hyundias, like the Venue, have a cleaner looking engine bay.

To remedy this, I wondered if there was a solution based on the Crosstrek or other Subarus where I could fit an engine cover from another model using a similar engine. The Impreza RS comes installed with an FB25D 2.5L, and with a little research, I found this Reddit post outlining the parts they found for their 2023 Crosstrek Limited, and it was the basis for my little project.

It works, and you will need the following:

• P/N 14025AA560: Engine cover for 2019+ Forester,
• P/N 14032AA230: Rear mount brackets for intake plenum (two required),
• P/N 14032AA290: Front mount bracket for alternator,
• Two M6 x 10 mm bolts for attaching rear mount brackets to the intake plenum,

The cost, taxes in, was about $176.00 CDN, and it took 3 weeks for the parts to arrive.

The parts diagrams for Subaru are famously atrocious (one would not get away with this in aviation). Many diagrams show only the cover and do not reference or show the associated hardware.

The good new is we will walk through the process of installing the cover, step-by-step. A image will be followed with an explanation and instructions.

Engine Bay Cover Install

Parts: as outlined previously.

Tools: 10 MM open or closed wrench, blue Locktite or 3 X M6 lock washers (stainless), rags.

These are the parts you will need. I am using blue Locktite in place of lock washers, and you can see the two P/N 14032AA230: Rear mount brackets for intake plenum below the tube of Locktite, followed by the M6 bolts and the P/N 14032AA290: Front mount bracket for alternator.

The engine bay cover (upside-down view) shows the corresponding attachment points for the engine cover and the correlated attachment points. Closest to the camera are the two slots that slide into the rear mount brackets, and behind them are the two clips that attach, one to an existing mounting bracket, and the other to the installed bracket.

The engine bay before installation. Note the pulley cover to the left of the oil filter. This will be removed. Note the nutplate bosses to the right and left of the intake plenum (silver inserts in black plastic).

Close-up of nutplates in intake manifold. This is were the rear mount brackets will go.

Take one of the rear mount brackets and an M6 bolt. Place a tiny amount of blue Locktite on the threads of the bolt and install the bracket with the black plastic oriented to the front of the engine.

Note the orientation of the bracket. It is facing FORWARD with the tang to the left. This is the orientation for BOTH brackets (left and right side). Tighten the bolts (I was not able to find the torque specs), taking care NOT to overtighten. I am not sure of the material of the nutplate boss and if it is aluminu,m the bolts, which are steel, will strip the threads and then you will need to replace them. Note the tang oriented into the slot built into the intake.

Once installed, the brackets will look like this. Properly oreinted to the front of the engine. Note the tabs on both brackets fit into the plastic slots on the intake piping.

Remove the belt and pulley cover next.

Remove and retain this bolt. You will need it for the bracket you will be installing next. Note that the cover has a plastic pin (right side) that is slotted into a corresponding hole in a bracket. Remove bolt and pull gently and firmly up, releasing the plastic pin attached to the cover. Remove cover.

Access and view with the cover removed.

Close-up of the receptacle for right front plastic pin.

This is an image of the nut embossed in the body of the alternator. Note the "U" shaped receptical above the hole and the black tang on the black bracket. They mate when installed.

Reusing the bolt that held the previous belt and pulley cover, add locktite to it and position the black bracket so the tang of the bracket fits in the "U" slot on the alternator bolt boss. Tighten. But do NOT over tighten, because if you strip the bolt boss you may have to rethread the boss or get a new alternator.

Once the last bracket is installed, review your work. You should have two rear mount brackets installed and pictured, and the alternator bracket installed, with the existing bracket on the right side of the engine, by the oil filter, being ready to accept the engine bay cover.

Orient the engine bay cover with the logo and text facing the front of the engine bay and slip it into place. It goes in "flat", at a horizontal angle with a slight tip up at the front of the cover. The "feel" for the two brackets on the intake plenum is not, at first, positive, but with a bit of patience and hunting you will find it slips in and feels like there is an interference fit between the plastic ends of the bracket and the receptacles embossed in the plastic. You know you got the pins properly aligned and fitted when the forward pins that go into the rubber grommets on the forward side of the engine align. You cannt see the pin/grommet on the right, as the engine bay covers it, but you can see it on the left. With a bit of slight jostling, you will get a positive engagement.

You're now done, Sports Fans! She looks good, and with the acoustic padding on the underside of the engine bay cover, the engine runs a little quieter.

My driving impression is that engine noise is less noticeable, and I plan to test this formally in an upcoming post.

Suffice to say, I am pleased with the more finished look of the engine bay with the cover.

Door Sill Protectors Sourced

 Been meaning to post this...

Some context. I bought my 2024 Subaru Impreza RS in July 2026 and immediately went looking for bling and functional bits and pieces to enhance my ownership experience.

I really wanted some door-sill protectors and went to Weathtech to find some and, at the time, the site showed a set as a future product and the facility to enter an email address to be updated when they became available.

Fast forward to January 2025. No update and having purchased a front set of WeatherTech floor mats I went back to the site and there was no update.

I decided to buy the set for the Crossteck. As this model is based on the Impreza I was pretty certain the dimensions would be the same so I got them direct for the MFG. and the test fit looks good.

I have NOT installed them as it is cold up in Canada (NOT the 51st state) right now and I want the warmer weather so the adhesive sets properly.

Has anyone else done this?

Interior Bling for the Mist

 Good Day, Sports Fans!

The interior of the Impreza is upgraded from the Touring with power seats with grey patterned cloth with red accents. The buttons and knobs for the car and basic black plastic with some having a "chrome" accent, such as the radio ON/OFF knob, Tuning knob, and the bezel of the Start button.

With the red exterior paint, the Mist needed some additional additions to the interior to connect it thematically with the overall treatment of the interior cloth seats.

In response to this I purchased from Amazon a set of  LOCOY Center Console Knob Covers; LOCOY Center Console Armrest Cover; and ‎MOCHENT Cup Holder Inserts Liners for the interior of the Mist.

Images for Amazon.

Images for Amazon.

Images for Amazon.

The overall quality of the items was good and the following are notes related to the installation...

‎MOCHENT Cup Holder Inserts Liners

The liners are straightforward to install. Just match the shapes with the proper location on the car and way you go. Good build quality and fitment was good except for the large rectangle placed at the bottom of the console cubby. It was not quite the right size being slightly smaller than the actual shape of the console. A minor quibble as no one is going to see it.

LOCOY Center Console Knob Covers

These were easy to install.

Note that placing the red ring around the Start Button needs to be slightly off-center for me. When I first installed it, from my seating position, I could still see the chrome ring. I had not pressed it on hard so was able to shift it up. Take care when separating the cover for the tape. I needed to use the tip of my knife to separate the paper protecting the tape and the adhesive for the red starter ring cover appears delicate.

The knobs for the radio controls slip on with some interference. It did not damage the knobs but I do not think I will be ever able to take them off.

The knob for the side-view mirrors needed the thin tape provided. I measure out a piece 3/4 the diameter of the knob, taped the tape to the knob and slipped the knob over the tape. It was tight and with a bit of rocking, I got the new knob to seat properly.

The thin tape is used to firmly set the knob on the side-view mirror control.

It's not coming off either!

LOCOY Center Console Armrest Cover

This slips on with moderate effort. Plan out before had your positioning of the cover before you put it on the console if you bias the cover to the rear or to one side you will have to start over. It does not interfere with the lid locking and looks OK. I prefer the feel of the OEM material on my arm but I wanted to protect the arm as I am resting it on the rest almost all the time (as opposed to my Accent, where the armrest was too low).

Will the wrinkles be problematic?!?

As can be witnessed by the photos the material still has wrinkles. Not a deal breaker for me and we will see Sports Fans if over time the wrinkles disappear.

Overall Impressions

Knobs: 9/10. Why the fit for the radio knob is spot on and the mirror know not so much? Comments as to why there is no ring for the Trip Reset button are well-founded. Would be nice to complete the set with this additional piece.

Cup Holder Inserts: 9/10. I really like the red piping and the coverage which adds to the protection of the cubbies and cup holders. All the pieces fit perfectly save the one in the Center Console cubby.

Center Console Armrest Cover: Provisional 7/10. A better fitment on installation would add confidence to the use of this product. I will revisit these accories updating you on their durability and service in the future.

Well Sports Fans, for about a Benjamin you can get some nice accessories that personalize your Subie and add some bling to your pride and joy.

Drive safe and you know where the rubber goes!

Prepping the Red Mistress

 

The relative reliability of today's cars when properly maintained makes the need to bring tools and other items with your car effectively unnecessary. For example, the increased reliability of tires is represented in the Subaru Impreza by the fact it does not have a spare tire. It uses a tire inflator and some magic sauce to seal leaks temporarily until you can repair or replace the tire.

However, it still is a good idea to have some supplies on hand and the following photos show my preparations.

The first photo shows water and an inexpensive umbrella for those days when you are caught by the weather and do not have a jacket handy. The water is for convenience but I generally had 4 liters of water on hand.

The next photo is a basic camping lantern using LED lighting for general lighting in case of emergencies or if I am travelling, such as at a hotel, and the power goes out. I also have two other LED  flashlights in the glove box for that just-case scenario.

The next two photos are related. The top one is expanded representing the total items in the small cubby in the rear of the Impreza. First aid kit, oil, booster cables, paper towels, paracord with a 200 lb. capacity, lug bolt for removing wheels, rescue blanket, electrical tape, gloves and masks, brush for cleaning; a bag with utility knives, a multi-tool, a universal screwdriver. And that's about it. The photo below is everything set in place allowing me to put the floor on.

I also add some boxes of granola bars or fruit snacks in case of delays that necessitate some sustenance if required.

The glove box has another knife with a seatbelt cutter, a window-shattering tool, a Fox 40 whistle, and flashlights.

Today's mission is...

 Today was dedicated to getting a tint done on my Subie and going on a visit to a local Subaru parts and accessories shop.

Having done research into several local vendors I decided on All-Brite Glass and Tint in Kitchener, Ontario. I will post a more complete review of the process of getting this work done, suffice to say I am so pleased with the overall look and enhancement to the function of the tint. My main reason for the tint is related to when I travel. When going on an extended trip (1 to 2 weeks) I have to put the rear seats down to open up the cargo capacity of my car and having the dark tinted windows adds to privacy and security. Of course, when stopped overnight I remove all my belongings, but during the day and when stopped for doing tourist stuff it is comforting to know that it is difficult to see into my vehicle.

Once the tint was done I set out to the Subie Supply Co. in Brantford, Ontario.

Being excited to own a Subaru, a long-time dream, one does tend to gravitate to sites that help make your Subie your own.

As the 2024 Impreza RS is not "performance" oriented like the WRX because of its CVT transmission and it being sold in relatively small numbers compared to other Subaru models it is a bit orphaned in the aftermarket department for accessories and parts. Some parts for the Crosstek will adapt for use on the Impreza and that is one alternative route to "soup up" my Subie.

But... There are still things you can do and I will share with you my additions or substitutions. There won't be any major mods to my Subie as she has to remain "stock" until the engine warranty is complete. There are some engine mods I can make for functional and appearance benefits.

As to the tint...

The window switch is placarded to not use the windows for between 3 to 5 days to protect the tint and avoid damaging it. And I have placed a daily reminder in my Google Calendar to help prevent me from using the power windows

No Drive Though for YOU!