Why is Choosing the Right Air Filter So Crucial?

A Guide to All Things Air Filter: Starting from Noobville

I’ll be assuming you know next to nothing about the combustion engine. And that’s just fine. I can remember when I was five too. Those of you who know all about the processes that propel your gas guzzling Jeeps and diesel drinking pickups on down the road don’t need this intro. Heck, you probably don’t even need to read any of this because you already know the importance of selecting the right air filter for your ride. This knowledge bomb is for those of you just getting started. We’ve all been there. Help me help you, bro.

Combustion 101

Whether it was in shop class or your daddy’s garage, at some point you heard your first explanation of the combustion engine. It’s been a long while now, but I think I first learned about it while helping my pop work on his old Dodge pickup--a hydraulic dump truck, as a matter of fact--not that the specifics really matter.

I asked him a question, probably unrelated to what we were working on, and he just took off on a rant about the wonder of the combustion engine, how fuel is ignited inside each cylinder, creating a micro-explosion of power, pumping pistons up and down, creating torque and moving your truck forward. Yeah, we all remember this important lesson.

But the air filter may not have even been mentioned the first time you came to understand the inner workings of your engine block. Often this part comes later. Too many of us see the air filter as just another maintenance part that has to be replaced every so often, like your oil filter or your brake pads or even tires. All these parts are vital, but some are more important to getting peak performance out of your engine than others.

FUEL + AIR = BOOM

Until an elder mechanic explained it to me, I always thought that fuel, your gasoline or diesel (petrol, for any Brits out there) was the main component that drove your vehicle. And don’t get me wrong here--it is still vital. But even the most rich fuel source is meaningless without air.

A teeny tiny drop of fuel gets mix in with air (21% of which is oxygen), then compressed by your cylinder piston to the optimal pressure. Then BAM! The spark plug lights it up. But the petroleum product is really only the catalyst. The air, and specifically the oxygen rich part of your atmosphere, is the real fuel, the real power behind the throne, so to speak.

This means that the most important and often overlooked parts of your engine is your air filter. If you don’t have a steady supply of clean air coming into your cylinders, it doesn’t matter what premium gasoline or high octane diesel you’re pumpin’ into your tank. The engine won’t get maximum performance without cool, clean oxygen. And now you know just how vital a proper air filter is to the whole combustion system that drives your ride.

Pro Time: Dry or Oiled Filters?

Now that you know the importance of your air filter, the next big question we often hear is should I get an oiled filter or stick with a dry one? That’s a great next question to deal with once you know you need a better air filter than your stock one. Believe it or not, the answer to this query might have a lot to do with where you live and how you drive.

So before we move forward, ask yourself these simple questions:

1. Where do I live? Or where will I live when I’ll be driving this truck / Jeep?
2. How do I want to drive this vehicle? Off-road? Towing? Is max performance a must?

The Big Climate Question

No, I’m not talking about climate change. I’m talkin’ about where you live and more importantly where you plan to be driving. If you road trip a lot for pleasure or for work, then we need to think about the conditions your truck or Jeep will be in most often when on the road. If your clime (fancy way of saying the climate of the place you live--ain’t I fancy?) is particularly dry and desert like, you’ll want to select a filter with that in mind. If you live in an area known for its humidity or frequent rain and snow, then you’ll want to consider this when selecting your filter.

The Quick (Not Dirty) Answer

• Dry, Desert-Like Climate: Choose a Dry Air Filter
• Any Other Climate: Consider an Oiled Air Filter

Dry Air Filters

So chances are unless if you opted for a performance trim level, your stock air filter is most likely one of these. There’s nothing wrong with a dry air filter either. These beasts are designed to be economical and to meet the minimum standards for air filtration. But every time I read that word “minimum,” I just get fumed up. Cause what does that mean exactly? I mean, would you put in the minimum amount of effort on anything you were really passionate about?! Or would you give it your all? Would you go the extra mile? When I think of my truck, I know I always go above and beyond. In fact, it might be the only time I might be guilt of being called an “overachiever.”

Anyway, the point is this: dry air filters get the job done, and they do it on the cheap. Most dry air filters are made from white cotton fibers interwoven in such a way that they trap dust and debris and prevent it from getting into your engines and clogging up your precious cylinders. These fibers are spread just far enough apart to allow the gaseous air to pass through unhindered while trapping any small particles that might be floating on those air currents.

And that’s the goal of any air filter. You want a filter that prevents any solid debris or pollen from getting into your engine. But you also want a filter that allows the proper amount of air flow or pressure to get through and into each cylinder. There’s the conundrum. How do you balance air flow while capturing any infiltrating particles floating in that air?

Dry air filters trap these potential engine pollutants in the gaps between the cotton fibers. And they do a great job of this. However, as more and more dust and dirt gets caught up in this web of cotton and foam material, the filter gets more and more clogged. And before you know it, your engine can no longer breathe. That’s right, as a dry filter does its work and becomes more and more dirty, it gets worse at allowing air into your engine.

This doesn’t necessarily mean it gets worse at preventing particles from mucking up your engine, but without proper air flow, see above--your engine isn’t going to be able to go as well, if at all. And this is why dry air filters need to be replaced every 10,000 to 15,000 miles or so. Some dry filters are even reusable. They just require a special cleaning chemical to be applied after you bang out all the dirt and dust of course, and voila: she’s nearly good as new.

So therein lies the pros and cons of the dry air filter. As these filters do their job of keeping your engine squeaky clean, they become less effective at doing their other job of allowing good air flow into said engine. So they have to be cleaned and/or replaced regularly. Chances are you are already well aware of this regular maintenance. So it isn’t really that big of a concern, right?

Wrong. Here’s the thing. As soon as a dry filter starts to get dirty, air flow starts to decrease. So a few miles on down the dusty trail and you are suddenly no longer getting maximum performance out of your engine. That’s the real issue here. It isn’t that dry air filters aren’t great at filtration, cause they are. It is that at they filter out dust and dirt, they limit your air flow.

So Why Should I Stick with Dry Filters if I live in a Dry Climate?

Great question. This one actually has more to do with why you don’t want an oiled filter in a dry dusty area than why you would want a dry filter. If you live in the dust bowl area of the US, and that includes high plains desert areas, then you probably do not want to upgrade to an oiled filter. High levels of dust in the air will clog up an oiled filter just as fast as, if not faster than a dry oil filter. If you are going to have to clean your oiled filter constantly, then you are likely just as well off going dry. Hate to tell you all this, cause at this point we all know that oiled filters are highly superior, right? Well, I’ll get to that part shortly. But first…

A Climate Breakdown: US States & Dry Oil Filters

So cause I like it when peeps just spell it out for me, here’s the areas in the United States where you should probably consider sticking with a high performance Dry Oil Filter over an Oiled one:

• Texas
• New Mexico
• Arizona
• Nevada
• Oklahoma
• Nebraska
• Select Desert Parts of Southern California
• Eastern Parts of Colorado, East of the Rookies
• Eastern Parts of Wyoming, East of the Rookies

Of course, this really depends on your local area. I can’t rightly say that all of Texas is super dusty because if you are in certain parts of larger cities and suburbs, of course, there may be less dust in the air. Likewise, the parts along the coastline tend to have a more moderate climate. And then there’s Austin, with all that music in the air mucking up your truck’s air flow. Just playin’, Austin.

We could say the same about certain high plains deserts like those found in parts of Colorado and Wyoming. But in general, these areas are the ones where we would suggest you consider for yourself whether or not it is worth the hassle of going with an oiled filter. Now for all the reasons why you should go oiled if you can.

Oiled Air Filters

The Bee’s Knees for All These Reas...ons

That didn’t quite play out poetically as planned, but you get the point. Oiled Air Filters truly are superior to dry, most of the time. An air filter is an air filter, you may say. But here’s the dealio. While both oiled and dry air filters use gaps in their filtration material to trap debris while letting air through, oiled filters have larger gaps, which means they have better air flow.

If you want maximum performance out of your engine, then you need maximum air flow, while still protecting your engine from damaging dust and dirt particles. Since oiled air filters maximize air flow while preventing debris from getting in, they are superior to dry filters. Done. Nuff said.

Here’s the reason you shouldn’t go with an Oiled Filter in a dry climate: it has to do with how they filter out dust and dirt particles. The oiled part. Oiled Air Filters are able to have wider gaps because the material is coated in oil. Cleverly named, right?

The oil allows the air to move on through fairly unrestricted, while at the same time it captures dust and dirt. This is the big reason why oiled filters are so superior. The debris gets caught still, but the oil keeps the material from getting clogged as quickly, still allowing for that superior air flow. However, oiled filters require an additional level of maintenance. And if you are in a drier climate, you may have to perform this step more often, so often, in fact that it may become a real hassle.

Oiled Air Filter Maintenance

As the oil captures more and more dirt, you’ve gotta clean ‘er up. If you have used a reusable dry air filter before, then you have some experience with the first part of this maintenance. If you only ever replaced your air filter, this is new territory, and hence an added step to your regular maintenance schedule. Most customers find they clean and re-oil their air filter roughly on the same schedule with changing their oil filter and engine oil, but you should check the air filter more regularly than this, especially if you’ve been driving in a more dusty environment as of late. Most oiled air filter manufacturers recommend you do this every 5,000 to 6,000 miles at least. I find it easier to just do air filter maintenance at the same time I do my oil changes for this reason. And this schedule helps to keep your air filter at peak performance.

Each oiled air filter comes with its own instructions that should be followed to the T. Most recommend a particular cleaner or chemical to remove the level of dirt and grime that builds up on the filter. Likewise, add the appropriate amount of oil onto the filter afterwards. I’d love to give you some general advice here, but depending on your vehicle and the size of the filter, the amount of oil can really vary. And if this all sounds like too much work, then don’t worry about it. You can stick with a high performance dry filter or try a reusable / cleanable dry filter. You won’t get quite the engine gains, but you’ll still get some over the stock filter. And you won’t have the added maintenance to worry about.

Why You Should Opt for an Oiled Air Filter 

Unless if you are in that desert environment we mentioned above, an oiled filter is really the way to go. And here’s why: 300% more airflow. Yeah. 300%. And since your engine runs mostly off the oxygen in the air, you will see more performance gains and get the most out of your vehicle if you are using an oiled air filter.

Now if you are just using this vehicle as a daily driver or to commute, then maybe dry is fine for you. But if you need to get the most out of your ride, if you plan to tow often, if you want to enter into truck pull competitions, if you off-road often, if you have dreams of racing at all, or if you just like the best parts available installed on your vehicle, then go oiled and you can thank us later.

Selecting the Right Filter for Your Driving Conditions

We hope this guide helps you pick the best air filter for your truck or Jeep. In the end it does come down to where you live and how you drive. In general though, the oiled air filter is where it is at. However, it does come with the cost of some extra maintenance, but if you want the best filter around then there is no contest. We offer a variety of top-notch dry and oiled air filters. Whether you go with K&N, aFe, S&B, Perrin, Flowmaster, or AEM, we have the best air filters on the Internet. And our prices are always the lowest around. Couple all that with free shipping and free returns, and we think you’ll want to shop with us from now on for all your truck and Jeep accessories.

In the meantime, if you have any questions about air filters, hit us up via the live chat, by phone, or by email. We have some of the best customer service people around, and they are familiar with these products. They’ll tell you true. No nonsense.

And if you’re ready to order, start shopping now for your next air filter. We’ve got ‘em in stock and ready to roll out to you. Buy a performance grade air filter from Midwest Aftermarket today.