You know who else thinks all of these things are a pain and keeps it from performing it's best? Yes, your dog too, but that's not the answer I was looking for...
Your Subaru!
Specifically, your Subaru's engine. Gas engines are nothing more than an air pump. The air mixes with fuel and combusts, thus making power to push pistons up and down and eventually move your wheels. But, your engine is a fickle chap. It likes operating within its parameters given to it by our Subaru engineers in Japan and it HATES dirt. HATES IT! Solution? A filtering device to rid the air of all the foreign debris before your engine ingests it. An air filter! Perfect!
Yes, an air filter is a must on virtually any gasoline powered engine, even your lawnmower has one(great, now you're going to have to change that one, too. You're welcome.). But, an air filter will filter enough junk out of the air to the point where it is "filled up", and less air will be able to be ingested into your engine. Remember those parameters I mentioned a minute ago? Yes indeed. Your Subaru likes its parameters. You see, among thousands and thousands of formulas and ratios and percentages your Subaru's computer is computing every nano-second, the amount of air being sucked in by the engine is one of them. Your Subaru knows if you step on the gas pedal "this much", then "this much" air will be coming into the engine and it needs to provide "this much" fuel to keep everything running smoothly. Now, the computer can compensate for slight variations due to many factors, one being...you guessed it, a dirty air filter. But, by compensating, your computer says,
"I'll keep this motor runnin' for ya, but I gotta kick the power back a little, and your gas mileage might take a bit of a hit, too. Hey, what do ya want from me? Change the air filter, rockhead. It ain't that hard!"
So, yes, your car will run with a dirty filter, probably good enough that you really don't notice it on a day to day basis. But little by little, you may start noticing a drop in mpg or a little loss in power on some of the hills on your daily commute.
Thankfully, changing your air filter is inexpensive, is a relatively quick job, maybe 15 minutes of your first time, and it will have your Subie running back at its peak performance. Now, chances are because your car will compensate for a dirty filter, when you replace your dirty one with a fresh filter, you are not going to notice some incredible performance increase or start getting 70 mpg, credit those Subaru engineers for keeping the engine running good under all conditions. But, take comfort in knowing that your Subaru's engine will indeed run better and more efficient by being maintained properly, including a fresh air filter.
So, now you are asking yourself, "OK, so how long does it take for a filter to call it quits?". Good question. Now, Subaru says every 30,000 miles. But...and that's a big but...they also say you should replace it more often under dusty conditions. Kind of a round-about way of saying replace it every 30,000 miles if you drive in a bubble, but you might want to check it more often. Have a look at this air filter at 15,000 miles:
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| A lot of junk can accumulate in 15000 miles! |
It's had it. And don't be a cheapo and try to clean the bugs out. Replace the filter.
The cost of an OEM(Original Equipment Manufacturer) Subaru air filter is usually less than $30. I don't think it's out of the question, especially around here in central PA, to just make a point of replacing it every year. We all probably spend $30 a year on stuff that is meaningless, so at least this is actually going to something well worth it. And considering that the $30 air filter is protecting an engine worth thousands of dollars, its a no brainer.
Now, what air filter to get and where to get it, and what about those air filters that you just clean and they give you more power and more gas mileage and more.....Easy kid. One thing at a time. First off, my opinion will never waiver from this...nothing fits as good as OEM. I would always recommend paying a bit more for OEM Subaru parts whenever possible. There are some exceptions from time to time, but they are just that, exceptions. Can you go to one of the big box stores and grab a filter made to fit your car and save a few bucks? Sure you can. But, be aware that those aftermarket filters do not make a different size filter for every single car on the road. The filter for your car may be a fraction of a millimeter off in exact size due to that filter being able to fit 15 other cars if they make it a touch smaller or larger. That could mean the difference between a perfect fit and trouble free install, or not. But, the choice is yours.
The "renewable" air filters that claim an increase in horsepower and mpg, well, I revert back to the parameters set in the factory computer. Even if the filter does allow more air in, the computer will only compensate for so much. There are countless performance shops that have dyno'ed Subarus before and after hi-flow air filters, and on an otherwise stock Subaru, gains were virtually nothing.
Regardless, keeping your Subaru's engine breathing as free as possible with a clean air filter is one way to ensure endless miles of problem-free driving, and you won't have your car's computer calling you names under it's own breath!
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