The Real Cost of Your Car’s Cheap Factory Air Filter

Air Filters Selection

In today's world, saving money wherever possible has become essential. But it's important not to lose sight of the fact that, sometimes, a product that costs more up front will save you more money over time. In our business, we've seen far too many consumers judge products solely on the basis of their initial cost, completely neglecting any long-term economy and benefits. When it comes to automobiles, "performance" air filters are a perfect example of this.

Stock Vs. Aftermarket Air Filter
In this article, we'll discuss the benefits of upgraded aftermarket air filters that are designed to fit in your vehicle's stock air box assembly with no modifications.

In this article, we'll discuss the benefits of replacement air filters designed to offer higher levels of performance. We'll start with the basic facts - these performance air filters cost more because they're made from more expensive filtering material that can be washed and re-used instead of being discarded every 15,000 miles. At quick glance, the comparison of a performance air filter at $45 and a traditional paper air filter at $20 would lead consumers that care only about initial cost to choose the paper air filter. As we'll also show with examples, such a choice would be false economy.

Neglected Car
People that buy new cars are keeping them longer than ever. Performance air filters cost more up front, but start saving you money quickly because they can be washed and re-used every 15,000 miles instead of being replaced.

According to a study by the automotive research firm R.L. Polk & Co., people who buy new cars are now holding on to them for approximately 6 years. Considering that most Americans drive 15,000 or more miles per year, by the end of those 6 years the average car will have traveled almost 100,000 miles. If you change the paper air filter at the 30,000-mile interval recommended by many automobile manufacturers, you will have purchased 3 paper air filters during that time period.

However, browse the internet and you'll see that most automotive experts recommend that a paper air filter be replaced far more often, closer to every 15,000 miles. Going by that maintenance schedule, you'd purchase 6 new paper air filters. Do the math again and you realize the extra cost of the paper air filters jumps from $60 to as much as $120. Suddenly, that one-time $45 expense for an aftermarket air filter doesn't look so bad.

Cross Section Of Typical Paper Air Filter
This cross-section of a typical paper air filter with wood pulp construction shows 1. Airflow, 2. Dirt building up as air passages become plugged, 3. Irregular passages result, 4. Airflow decreasing as fibers swell from moisture or blow-by, and 5. Turbulent filtered air that causes reduced power and fuel economy.

Looking beyond mere initial costs, the technology behind aftermarket filters allows them to save you even more money during driving compared to original equipment paper filters. The reason? Paper air filters are made of wood pulp that's bonded together and formed into pleats. While they generally provide adequate filtration, it comes at the expense of airflow because of the nature of the paper material itself. More specifically, passages in paper air filters need to be particularly small in order to be effective at trapping dirt. So even in brand-new condition, these small passages are very restrictive. Even worse, as the filter becomes dirty, these passages become clogged - further choking airflow into your engine.

Any time airflow is reduced, the computer controlling the fuel injection system has to try to compensate and adjust the fuel delivery to maintain a combustible air/fuel mixture. The result will be a less-than-ideal mixture, poor combustion, reduced performance and poor fuel economy. Most aftermarket air filters are constructed from multiple layers of cotton gauze, which are sandwiched between wire mesh that's formed into pleats. The layers of cotton fibers are able to trap dirt particles that are even smaller than the holes in the paper filter media. Furthermore, dirt is trapped in the depths of cotton filters where they don't block airflow so much, unlike paper air filters which mostly gather dirt right on the surface. With cotton air filters, airflow stays consistent between cleanings for optimal combustion - maximizing performance and fuel economy.

Most aftermarket air filter manufacturers do not make fuel mileage claims because it would impossible to predict the numerous variables involved: driving characteristics, weather, road conditions, and more. But for the purposes of creating a specific comparison, let's say your car gets approximately 20 miles per gallon and you pay $2.50 per gallon at the pump. At 100,000 miles you'll have spent approximately $12,500 for fuel. Even if you only realize another 1/10 of a mile per gallon using an aftermarket filter, you'll have $62 more in your pocket. And if you get as much as one additional mile per gallon, your savings go up to $595. If you stayed with the paper air filters those savings would have to be added to the "cost" of the filter, so now their real total cost would be anywhere from $182 to as much as $715! Suddenly, a $45 aftermarket air filter (even one that lasts 'only' 50,000 miles) is looking very, very good.

Another cost that goes beyond money is the beneficial effect aftermarket air filters have on the environment. Most people, even car buffs, are becoming more conscious of recycling and doing everything possible to preserve the world for younger generations. Using an aftermarket air filter helps the cause by allowing your vehicle to consume less fossil fuel and produce less harmful emissions. Additionally, they prevent used paper air filters from ending up in landfills. And last but not least, when more drivers convert to washable and reusable filters, fewer trees will have to be cut down in order to produce traditional paper ones.

'Oiled' Vs. 'Non-Oiled' Air Filters

Typical Kit For Cotton Air Filters
Shown here is an example of a typical kit for cotton air filters that features both cleaning solution and oil.

Air filters made of cotton gauze or woven cotton are designed to work best when they're sprayed with a special oil that creates a stickiness on the cotton's microscopic fibers. This serves to trap the smallest particles that otherwise might make it through. Cotton filters usually come with a kit that includes one bottle of cleaning solution, and another bottle of oil to spray on the filter by hand when it dries after being washed. In other cases, such kits are listed in Product Options. If you don't already have cleaner and oil, you'll definitely want to add this to your online shopping cart. Should you choose not to re-oil a cotton filter after washing it, no harm will come to the filter or the system. However, the level of filtration may be reduced if a cotton filter is left "dry". Filters that don't need to be oiled are usually "synthetic", which means they're made from artificial materials such as polyurethane.

Washing A Cotton Air Filter

Washing Cotton Air Filter

Unlike paper air filters, those made of cotton can be washed. This process is relatively easy. Instructions that manufacturers will include may vary slightly, but they'll follow the same basic pattern. Once a filter is detached from the vehicle, first thoroughly spray the cleaning solution on all sides of the filter including the inside area of conical air filters as well. Wait approximately 15 minutes (don't lose track of time and let the cleaning solution dry), then thoroughly rinse the filter clean under running water. Shake excess wetness out best as possible and allow the filter to sit until it dries completely. At that point, spray the oil on - noting that flat filters should be oil-sprayed on both sides, and conical filters should only be sprayed on the outside surface. Allow it to dry for another hour, then wipe off any excess oil before putting the filter back on your vehicle.

Filters Available As 'Vehicle-Specific' Or 'Universal'

Vehicle Specific Product Options
Universal-fit air filters will features a rectangular blue "Dimensions" button. Click on this to open up a helpful pop-up box which will show sizes available along with corresponding part numbers you'll need to reference.

As you look through our performance air filters, you'll see individual products will be noted as "vehicle-specific" or "universal fit". Vehicle-specific products will prompt you to enter make, model, and year because they're tailor-made to match the needs of your specific car or truck. Universal fit products are designed for any automotive application, and need to be selected by dimensions. For example, round air filters will specify outer diameter, inner diameter, and height measurements - in inches. If you see a "Dimensions" indicator button on the screen, click on it. A pop-up box will open with measurements available and, in many cases, corresponding part numbers to make a final selection further down in Product Options.

Flat Panel Style Air Filters

Flat panel air filters are replacements shaped and sized like the original equipment paper filters your vehicle came with off the assembly line. They offer improved airflow and the ability to fit in your OEM air box housing without modification. For most production vehicles, you'll find the sizes you need with K&N's 33 Series Air Filter, aFe's Pro5R Air Filter, or Airaid's Air Filter. All of these are cotton gauze and designed for use with oil. Should you prefer not to use oil, Airaid offers a synthetic polyester/rayon version of their filter which operates dry. There's also the synthetic aFe Pro Dry S Air Filter. And for select Subaru- and Nissan-powered vehicles, Perrin Performance offers the Panel Air Filter with polyurethane foam construction. For newer Mini models, Alta Performance also offers a flat foam filter as well.

Flat Panel Air Filters
Perrin Performance Panel Air Filter
The Perrin Performance Panel Air Filter.

Round Air Filters

For older cars and trucks equipped with round air filters, we've got a great selection of universal replacements that pop right in and go to work. (NOTE that with these universal-sized filters, you will need to know the diameter and height of your existing filter.) For those who appreciate a custom look not seen every day, the Green Filter cotton oiled Color Match Round Air Filter offers a variety of sizes. Oil for the filter is available in seven different colors, and it serves to change the color of the cotton when applied after cleaning. Airaid offers a harder-to-find 16-inch size older vehicle owners may appreciate with their Sweet 16" Round Air Filter, available in heights ranging from 3 to 5 inches. Green Filter also offers larger diameters with their Round Air Filter.

Round Air Filters
Green Filter Color Match Round Air Filter
The Green Filter Color Match Round Air Filter.

If you've got a vehicle equipped with General Motors's 1979-85 5.7-liter V8 diesel engine, Spectre Performance offers the oiled cotton HPR Air Filter for these as well as other classic GM muscle cars from the late 1960s and early 1970s. And if you prefer advanced filters that don't require oiling, aFe's Round Air Filter is available in 100% synthetic "ProDry S" form and cotton/synthetic blend "ProGuard 7" in addition to the standard all-cotton "Pro5R" form (see Product Options).

Cone Air Filters

Airaid Cone Filter
If you take your vehicle to the track, Airaid's Cone Filter comes in several variations you may find helpful. In Product Options, you'll find track-only "Race Day" versions as well as mixed-use "Track Day" versions. Both versions are available in synthetic polyester/rayon construction and cotton/synthetic blends.

We've got a large selection of conical-shaped air filters, most of which are designed as replacement elements for aftermarket cold air, ram air, and short ram styles of aftermarket air intakes (see our related article "What Are The Different Types Of Air Intake Systems?"). Most automakers don't use cone-shaped filters as stock equipment, but for those that do, these can also serve as OEM-style replacement filter elements which also happen to improve on performance. So if you have a custom car or engine-swapped vehicle that uses a hard-to-find cone-style air cleaner element, try matching it up here. Choose by inside diameter of the hose, outside diameter of the base, overall diameter of the top, and overall height.

Green Filter Cylinder Air Filter
If your vehicle takes an air filter that's shaped like a cylinder instead of a cone, Green Filter offers multiple sizes of their Cylinder Air Filter.

If you've fitted your vehicle with a Green Filter brand cold air intake, we've got the replacement filter sections such as the woven cotton Green Filter Cone Air Filter and Dual Cone Air Filter (with two filters inside instead of one). Or, choose Green Filter's "Color Match" single and dual cone air filters - both of which let you choose from seven different colors of oil to customize the look of your filter element. We've also got Injen's cotton gauze High Performance Air Filter cone available in a wide variety of universal-fitting sizes. And if your vehicle takes a cylinder-shaped air filter that's not in the shape of a cone, Green Filter offers the Cylinder Air Filter.

Alta Performance Foam Cone Filter For Mini Cooper
Alta Performance's foam 2.75" Cone Filter, for "first-generation modern" Mini Coopers.

If you've got a 2002-08 Mini Cooper, Alta Performance has you covered with the uniquely-sized 2.75" Cone Filter with foam cell construction. And if you take your vehicle to the track, Airaid's Cone Filter comes in several variations you may find helpful. In Product Options, you'll find a "Race Day" version that's not suitable for use on the street because the filter is designed to only catch large debris. There's also the "Track Day" version that offers sufficient filtration to allow the car to be driven to and from the track. Both versions are available in Synthaflow (synthetic polyester/rayon construction) and Synthamax (cotton/synthetic blend) materials.

Monitor The Condition Of Your Air Filter

AEM Filter Minder Gauge
The AEM Filter Minder Gauge

If you're planning to invest in a washable air filter because of the benefits it offers, you might also consider purchasing an air filter condition gauge that we offer from AEM. This lets you stay fully aware the instant performance starts to fall from its peak - because, after all, isn't that why you own an improved air filter? It's a vacuum gauge that connects to any air filter and monitors the pressure flowing through it. As the filter gradually clogs, the needle will fall out of the green zone and enter yellow and red areas. In Product Options, you can choose dash-mounted or remote-mounted versions for gas and diesel engines.

In conclusion, switching to an aftermarket direct replacement air filter is a win, win, win move. The first win is for your wallet, because although the initial cost is higher, an aftermarket filter saves you real dollars over the long haul. The second win is efficiency for you and your car. And finally, the last win is for all of us because the reusable filter makes better use of natural resources and reduces waste.

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