Air filters are among the most important parts of any automobile. It is also one of the easiest components to swap with a performance-focused aftermarket part. Many companies claim that their air filter enhances the horsepower, torque and acceleration of a vehicle. Here is a video that explains how a performance air filter works and improves the overall performance of a car. This video has been uploaded by a YouTube channel named Engineering Explained.
In the video, the YouTuber tested four different air filters on a Subaru Crosstrek. The first one is the original air filter of the car, which has already done thousands of kilometres and contains a lot of dust and bugs, the second is a new OEM air filter from Subaru, the third is a low-cost air filter, and the fourth one is a K&N performance air filter. In the video, the YouTuber tested the car with each filter on a dyno and then measured the acceleration of the vehicle with a VBox.
Firstly, the vlogger tested the original air filter, which was full of dust and bugs. With that air filter, the Subaru Crosstrek produced 158bhp of power and 185 Nm of peak torque. The vlogger also says that dyno measured high since the Crosstrek develops 148bhp of power output. But, this air-filter test is still valid because it now serves as a baseline for the other air filters.
Then he tested the new OEM filter, and the car offered power and torque outputs of 160bhp and 185 Nm. One can see that with the OEM filter, the power output of the Subaru Crosstrek got slightly increased. On the other hand, the low-cost air filter develops 163bhp and 189 Nm of twisting force. The cheap aftermarket produced more power and torque. At last, the high-performance K&N filter returned 164.3bhp of power and 192 Nm of peak torque. As expected, the K&N air filter wins this competition by offering maximum power and torque outputs. This test simply shows that a performance air filter can slightly increase the performance of the vehicle. Moreover, it's quite essential to keep the cars air filter clean as it smoothens the airflow.