The air intake system on your vehicle is designed to remove any harmful dirt and debris by using an air filter, usually located in an air box on the right or left hand side of the engine bay.
The factory air filter is commonly constructed using paper fibres and sometimes cotton components to adequately filter the air entering the engine.
There are many aftermarket options available, claiming to be ‘High Performance’ and ‘High Flow’ filters that aim to increase power and fuel economy.
These filters can be broken down into two categories – dry paper type filters and cotton mesh oiled filters.
This comes down to the material they are constructed out of and whether they incorporate oiling into the filtration process.
Dry Paper Filters
Dry paper filters are usually designed to fit into the standard air box of your vehicle and can also reduce the airflow restriction, but maintain the filtration properties of the factory filter.
This is achieved by utilising better quality materials in the construction of the filter.
This allows better airflow into the engine, which can increase the power output and fuel consumption.
They are simple to fit, most of the time taking 5 minutes or less and are considered one of the best ‘bang-for-buck’ modifications that you can carry out to your vehicle.
The downside to these filters, is that they are required to be replaced more often as they restrict faster than standard filters.
Cotton Mesh Oiled Filters
The most common manufacturer of these type of filters is K&N, who have been manufacturing this style of filter since the 1960’s.
Instead of using paper elements, these filters use fine layers of cotton between gauze mesh to create a filter that has less restrictions and allows better airflow into the engine.
To maintain proper filtration properties, a thin film of specially designed oil is needed to capture smaller particles as they travel through the filter.
The benefit of these filters, is that they are designed as a ‘lifetime filter’.
This means that instead of replacing the filter when it is restricted, you can simply wash the filter underwater to remove the trapped particles, apply another small film of oil, let the filter dry, and refit back to the vehicle.
This is more cost effective and beneficial to the environment as it reduces the number of filters being thrown away.
A downside of this process, is if you apply too much oil to the filter, it can dislodge and make its way further down the intake, possibly contaminating other components, such as Air Flow Meters (AFM) or the throttle plate itself.
This can cause a reduction in performance, fuel economy and may cause the malfunction indicator light (MIL, or engine light) to illuminate.
Therefore, it is important not to over oil the filter when in the cleaning process.
When considering whether to replace your air filter with a high performance item, you will need to check with local authorities to make sure they are legal in your state, and weigh up whether you are happy with the factory filter, or are after something that may provide a slight performance increase.
Thanks to Fixed Price Car Service for this handy info on car air filters.