Should you buy an aftermarket air filter?

Most stock air filters in cars are made from paper. Paper filters are disposable, but they do a good job of keeping dust and debris from your engine’s intake. This component is vital in protecting your engine and is also regularly replaced after every year or after a certain mileage. 

However, this process of replacement can seem a bit wasteful, and buying a new filter often can take its toll on your wallet. Paper filters are affordable, but if you want to be able to clean and reuse your filter, and perhaps get a slight increase in power, then maybe you should consider an aftermarket filter. Take note that this will apply to most cars. More common models like the Toyota Vios, Honda City, or Toyota Wigo are quite often modified by their owners and the air filter is one of the first few modifications made. Of course, more performance oriented vehicles are also modified with an upgraded air filter, and these vehicles will be able to get more performance out of their engines with a simple filter change. That being said, your results may vary when you install an aftermarket filter, and performance will depend a lot on what cars you're using and what other mods you have installed on your car. 

There are many types of aftermarket filter elements from different manufacturers. The most common aftermarket option is oiled gauze. This kind of filter is made from cotton and a special oil that traps dirt while promoting increased airflow, without sacrificing engine protection. 

Gauze filters are the most common type after the stock paper filters. Brands like K&N are the most well-known manufacturers of aftermarket air filters, and they’re the go-to brand for many enthusiasts and even original equipment manufacturers (OEMs). Typically, gauze filters can either be oiled or dry. Depending on the design of the brand, a gauze filter may also come with a cleaning kit that will “recharge” the filter’s performance. After a certain amount of time, you will need to clean and recharge the filter. Dry filters will just need a good clean when they get dirty. 

Foam filters, on the other hand, use man-made materials to serve as engine protection. A well-known brand that sells foam filters is the Japanese brand HKS, with its mushroom filter. Foam filters are also dry filters, which means that most foam elements will only need a good wash in order to be reused. 

Stainless steel air filters are not recommended since the level of protection you get from this kind of filter is minimal compared with foam, gauze, and paper filters. These filters use stainless steel as a filter element. Because metal is not fibrous, trapping debris will be a challenge, and smaller particles might find their way into your engine’s combustion chamber. 

Aftermarket filters also come in many different shapes and sizes. Depending on what you want to do with your car or what your car already has, it is important to get the right type that will suit your needs. 

If you just want the most cost-effective solution in the aftermarket, the best way is to get a drop-in air filter. Just like its name, you simply take out the stock paper filter and drop-in the aftermarket unit. This filter is the simplest and most affordable option, and it may even yield the best results since many modern cars are designed to maximize the makeup of the stock airbox. 

On the other hand, the cone-type filters are more invasive. You’d have to remove the stock airbox plus you’d have to install a new pipe that will clamp onto your throttle body. Cone filters usually come in kits or can be purchased on their own. But be careful when purchasing cone-type filters, as installing an ill-designed filter may cause your engine to even lose power or make no power at all. 

Fuel economy is probably the most apparent and realistic change that you can observe after installing an aftermarket filter. Although, this could be a placebo, so it is important to log your data over a certain period to give you and your car time to settle in with the new filter. 

If you’re only changing the filter and doing nothing like tuning your car’s ECU, then don’t expect a lot of power. Only changing the filter actually has a minimal effect on the power your car makes, however, you could be seeing an improvement in engine response and power at the red line. Just don’t expect a night and day difference in terms of power. 

If you’re buying a reusable drop-in filter, which retains the stock airbox, cost effectivity will come into play as you don’t need to buy a new one when the time comes. A simple wash is all you need, then you’re good to go. You will only see the savings after a long period of time because all you’ll have to do is take out the filter and clean it, instead of buying a new one. However, you need to buy a filter cleaning kit and follow the filter manufacturer’s recommendations to recondition your air filter. Also, your car might perform more efficiently, so you could also save money on fuel. 

However, if you buy the complete air filter kit that is engineered for performance, cost effectivity is definitely not your priority. These more advanced intake systems feature filters that are tuned specifically for your car, which means that you could see a bigger performance increase compared with the stock airbox, and all the other benefits that come with a kit like this, because the filter element is also reusable. 

By having a reusable filter, you will also produce less waste. You can still recycle a paper air filter, given the filter element is swapped out, but reusing an aftermarket filter produces a lot less waste, and it also saves you a bit of money in the long run. 

For most cars, buying an aftermarket filter is not necessary. If you’re heading into it with the intent of making a lot more power, then you should be prepared to spend way more or get disappointed. Filters do help your engine breathe more, but the gains aren’t something that you will be able to notice a lot. 

The more reasonable expectations are increased fuel economy, long-term savings, and reduced waste. Making power is just the cherry on top. Without other supporting mods, the improvement will be marginal, but with other modifications, you could be seeing an even better gain. We also cannot deny that you get a sweet induction noise from the intake which will be more pronounced if you have a cone-type filter installed. 

However, we still recommend that you stick to your OEM’s recommendations, but if you were to invest in an aftermarket air filter, make sure it is from a reputable brand with tried and tested products. Go for products that are proven because your engine, without question, is very important.