K&N's replacement air filters are designed to increase horsepower and acceleration while providing excellent filtration. K&N filters are custom designed to fit into your existing factory FR-S air box for simple, fast installation. K&N stock replacement air filters for street vehicles are covered by a Million-Mile Limited Warranty. K&N Filters use oil to provide filtration, and can be washed and recharged using the K&N cleaning kit (sold separately).

The aFe high flow, oil-free OE replacement drop-in performance filter will out flow Subaru's stock paper filter which results in improved horsepower and torque for your FR-S. The Pro Dry S is composed of two layers of progressively finer mesh synthetic media provide convenience and easy maintenance, plus maximum airflow for superb performance results. Washable and reusable for many cleaning cycles, the tall evenly spaced pleats provide excellent dust holding capacity for longer service cycle between cleanings. aFe designed their Pro Dry S drop-in filter with urethane bump seal insures tight, no leak seal over the life of the filter.

For maximum airflow from a drop-in filter for your FR-S look no further than the aFe high flowing Pro5R. This oiled OE replacement drop-in performance filter allows significantly more airflow thanks to it's five layers of progressively finer mesh cotton gauze media. Washable and reusable for many cleaning cycles, the round topped pleats offer maximum surface area and deep pleats for excellent dust holding capacity for longer service cycle between cleanings. aFe's Pro5R ensures tight, no leak seal over the life of the filter.

The Perrin drop-in air filter for the FR-S uses a 2-stage foam filtration element to improve airflow in your stock air box; providing improved power and airflow while removing harmful particles from the incoming air. Using a special oil coating, the foam filter catches dirt particles while allowing air to pass unimpeded through the high-flow foam. This filter can be cleaned and re-oiled using the Perrin cleaning kit, sold separately.