The Importance of Clean Air Filters
Modern internal combustion engines run on an air/fuel mixture that’s precisely balanced to achieve optimum levels of combustion. Among other things, that mixture depends on clean fuel and clean air, the jobs of filters. Unfortunately, a dirty engine air filter can easily throw that ideal mixture off - enough to trigger a check engine light if numerous running conditions should get out of whack as a result.
A poorly-running engine may be a worse-case scenario, but it’s still a common one thanks to dirty and clogged air filters left in place longer than they should be. Not only does airflow into the intake manifold become restricted, it gets choppy, uneven, and unpredictable. In other words, it becomes a big problem for engine control modules, throttle bodies, and even catalytic converters to manage.
How Frequently Should I Replace My Air Filter?
As far as “when” you should replace the air filter, first and foremost, check your vehicle manufacturer’s service schedule. We will also be the first to admit that your unique driving conditions could cause you to consider a replacement interval other than what the car maker prescribes. For more detail on this subject, be sure to check out our companion article, “When Is It Time To Replace My Air Filter?”
Whichever replacement interval you decide on, once you plug in your vehicle’s year, make and model on our website, you will find both “repair” and “performance” air filters for sale. You have a choice, and life is all about choices. There is no one right answer, as the decision regarding an air filter depends on factors such as budget, driving style, road conditions, and desire for performance improvement.
In this guide, we’ll look at how “replacement” (OE factory style) and “performance” (aftermarket) air filters differ and the pros and cons of each. We’ll also look at a few sample customers and the choices they made.
Air Filters - Replacement
Automakers may consider engine air filters a non-critical item that will be replaced eventually anyway. As such, they may see air filters as a way to cut costs – especially on lower price point vehicles not designed for performance. We do not subscribe to this philosophy.
That’s why, in our Replacement air filters section, you’ll find top-quality air filters that match or exceed the performance of OE ones. They’ll fit in place properly like they should – without the installer having to pinch or cut the filter to squeeze it into the air housing box. A good air filter should not have to be wrestled into place, and there should be no doubt in your mind that a good seal has been formed once it’s installed.
Like OE engine air filters, our applicable replacements are made of wood pulp-derived paper that’s bonded together and arranged into pleats in order to create the highest amount of dust-catching surface areas possible. Many of our replacement filters feature improved embossing of the filter media to create pleats that are stronger and more stable. This means they will be less prone to bending or crushing into one another as they begin to fill with trapped dirt. This keeps airflow and filtration effectiveness maximized during the lifetime of the filter.
Additionally, aftermarket replacement filters use higher-quality materials around outer edges to create a better seal. By keeping out contaminants more effectively this way, less abrasive dirt ends up in the engine.
If there is a downside to OE-style replacement filters, it’s that their service interval doesn’t change. Depending on your driving conditions and annual mileage, you may still need to replace the air filter frequently. While the air filters on most modern cars are easily accessed, there are still time and cost factors. Another consideration in this era of environmental concern is the waste that’s created each time a used filter is discarded. It’s for many of these reasons that clients also consider their options on the performance side of the page.
Air Filters – Performance
Replacing an original equipment air filter with a performance air filter is one of the easiest and least expensive things you can do to squeeze more power and economy from your car or truck. No matter what you drive, we have direct fit performance air filters that increase airflow into your engine while trapping a greater number of contaminants.
If you live in densely populated areas with more pollution or desert states with an ever-present layer of dust, or you drive on unpaved trails with dirt flying – you should strongly consider installing a performance air filter.
In contrast to OE air filters made of paper/wood pulp, the filtering element in a performance air filter is constructed from cotton gauze, and/or a combination of proprietary synthetic materials which allow much better airflow. And unlike the paper filter that collects dirt on the surface, performance filters trap dirt throughout the depth of the filtering element.
As a result, you get consistently better air flow during the filter’s entire lifespan, without any sacrifice in filtration ability. This allows a longer service interval – in some cases, up to 50,000 miles or even all the way out to 100,000 miles. And since the filter element itself is made of a washable cotton material, you can clean and refresh it as often as needed. Once the filter’s been washed and allowed to completely dry, simply re-oil it (if required, with special filter oil) and put it back into service.
Studies indicate that this type of material provides nearly 40% greater airflow than paper, enclosed in an alloy mesh screen which helps the filter keep its shape and protects against larger debris and dirt.
'Oiled' Vs. 'Non-Oiled' Air Filters
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 may 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.
Performance filters that don't need to be oiled are usually "synthetic", which means they're made from artificial materials such as polyurethane.
The filter washing process is relatively easy. Instructions that manufacturers will include may vary slightly, but they'll follow the same basic pattern. Once a filter is removed, 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 as 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.
Long-term Costs of Replacement & Performance Filters
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 may be false economy.
According to recent studies by automotive research firms, the average new car is kept for 6.5 years – with approximately 13% of car buyers holding on to what they purchase for 10 years. Considering that most Americans drive 15,000 or more miles per year, the average car will have traveled almost 100,000 miles in 6 years and 150,000 miles in 10 years. From a routine maintenance standpoint, changing the paper air filter at the 30,000-mile interval recommended by many automobile manufacturers means 3 new filters in 6 years, and 5 new filters in 10 years.
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 to 10 new paper air filters. Do the math again and you realize the extra cost of the paper air filters jumps from $60-$120 to as much as $120-$200. Suddenly, that one-time $45 expense for an aftermarket air filter doesn't look so bad.
Most aftermarket air filter manufacturers do not make fuel mileage claims because it would be 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. At 150,000 miles, your fuel costs would be $18,750.
Even if you only realize another 1/10th of a mile per gallon using an aftermarket filter, you'll have $62 to $93 more in your pocket. And if you get as much as one additional mile per gallon, your savings go up to $595 in 6 years or $892 in 10 years. 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 performance 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, the use of a cleanable air filter eliminates 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.
Below, we’ve included two sample customers, their vehicles, driving needs, and a replacement or performance product that best fit their needs. While specific air filters they selected may not be available for all vehicles, we encourage you to enter your year, make, and model to see other like products we’ve got for your specific car or truck.
2012 Honda Civic
As a fan of efficiency and frugality, Patty purchased a 2012 Civic to keep the costs of a long highway commute to a minimum. Since she managed the books for a small business, she also understood that higher upfront costs for certain investments often translate into a higher amount of money saved in the long run.
Patty applied the same thoughts to automotive maintenance – especially since she racked up miles quickly. For example, using more expensive synthetic motor oil ended up saving her money because it did not have to be changed as frequently (plus it offered better lubrication in cold winter starts when most engine wear occurs).
Periodically inspecting her air filter, Patty noticed the factory style paper mesh filters typically reached the end of their lifespan around 15,000-20,000 miles. Looking for a better long-term solution, Patty contacted CARiD to see what was available.
Patty then learned about performance engine air filters and how they stack up against OE style ones. Ultimately, she decided on the Performance K&N 33 Series Panel Air Filter. Made of cotton gauze, this filter was washable and reusable. Because it cost so little to pop the filter out, wash it by hand any time, then re-oil it for use, Patty appreciated how easily that allowed her to keep it in like-new condition for peak airflow efficiency – paying her back may times over by maximizing mileage and saving fuel.
2015 Dodge Charger
After years of saving, Robb became the proud owner of a 2015 Dodge Charger V6. While it doesn’t have the power of the Hemi V8, the base 3.6-liter engine provides powerful acceleration nonetheless – along with relatively decent fuel economy that doesn’t break the bank. With rear-wheel-drive, Robb also truly enjoys the car’s handling abilities not found in his previous crossover vehicle.
Because Robb lives in a perpetually damp climate, he noticed the one-car garage unit assigned to him with his apartment complex (his only parking option) tends to become quite humid inside. Without electrical outlets to run a dehumidifier, he realized he needed to be vigilant about surface mildew which constantly built up on horizontal surfaces – inside the car, and under the hood. Since he works from home, his car sometimes sat for days at a time.
Concerned about moisture and mildew inside his vehicle’s airbox, Robb decided he preferred to go with completely replacing his air filter more frequently – regardless of miles driven. Without access to an outside hose, replacing the air filter was also simpler and easier than washing one out.
He chose the Mahle Air Filter (replacement OE style) because its price represented excellent value, and he appreciated its high-quality sealing elements around the edges which reduced the amount of moisture entering the filter box.
To sum things up, if you’re happy with the lifespan and performance of your vehicle’s factory air filter, you may prefer the unwrap-and-install convenience of our OE style replacement filters - many of which provide improvements over factory parts you’d pay more for at a dealership.
If you don’t mind spending a little more upfront for a washable, reusable air filter found in our performance filters section, you’ll benefit from a lifetime of improved fuel economy and/or power. We don’t hesitate to mention if you’ve built up your engine in other ways for more power, a performance air filter is definitely worth your while.
We understand you may have questions about air filters you see on our website. We’re happy to help make your shopping experience easier, and that’s why we have knowledgeable product reps on call seven days a week that will be glad to listen and share any expert advice possible – without high-pressure sales tactics. We look forward to hearing from you!