In the world of automotive performance, there is no shortage of aftermarket parts that promise to increase horsepower and torque. One of the most popular options is a high-flow air filter, which is said to increase horsepower by 3 to 5 HP and improve fuel efficiency. But do these filters really make a difference?To answer this question, we need to look at the science behind air filters. Air is a critical factor in the internal combustion process that occurs inside the engine, and ensuring that your vehicle has adequate airflow can maximize engine production and efficiency.
This is where high-performance air filters come in. High-performance air filters are designed to provide better filtration than standard paper filters. K&N filters use a depth charge to provide filtration for your engine rather than barrier filtration like other filters use. Other types of high-performance air filters on the market include Cotton Gauze filters manufactured by the popular brand K&N, foam filters manufactured by companies such as ITG and Pipercross, and stainless steel mesh filters commonly used for races where engines are regularly rebuilt.
To test the effectiveness of these high-performance air filters, automotive journalist Matt Fenske conducted a series of tests on a Subaru WRX STI. He compared the performance of four different air filters: the original filter that came with the car after thousands of miles, a new Subaru OEM filter, a low-cost CarQuest replacement, and a K&N air filter. The results were surprising: while the original new and dirty filters were almost identical in their sprints (9.01 seconds from 20 to 60 mph and 3.61 seconds from 45 to 60 mph), aftermarket air filters improved that performance. The K&N filter was able to reduce the 0-60 mph time by 0.3 seconds and the 45-60 mph time by 0.2 seconds.
The CarQuest filter was also able to reduce the 0-60 mph time by 0.3 seconds and the 45-60 mph time by 0.1 seconds. Fenske suggests that the increase in power could be the result of less filtering, especially in the case of the cheaper CarQuest filter, although because it had no way of testing the filtering process, that aspect was not observed. So, do high-performance air filters make a difference? The answer is yes! While the amount of released horsepower you'll get from an air cleaner drop is negligible, you can get improved throttle response, slightly better mpg, and maybe a few horsepower if you use a drop down panel filter or cone filter with a thermal protection tube & cold air intake (if available). K&N purchased the original red oiled air filter for the automotive market and, to this day, they are innovating industry-leading filtration technology that offers exceptional protection against everything from superior fuel skidders to commuter vehicles around the world. For the average driver, installing one of these high-performance air filters may not have crossed your mind or you may have wondered if it was worth spending the money. But if you do some basic tests, you'll find that these aftermarket air filters do work and can make a difference in your vehicle's performance.