Add some horsepower to your 2015-2021 STI with the new Mishimoto Performance Air Intake. This kit is engineered specifically for your 2015-2021 Subaru STI and includes everything needed to replace the restrictive stock airbox. Our engineers spent months fine-tuning this design in an attempt to squeak out every last bit of performance. This dyno-proven air intake provides 20 whp/18 wtq gains over the stock intake while maintaining safe air/fuel ratios, perfect for some extra punch on the street or autocross course. The Mishimoto Subaru 2015-2021 STI Performance Air Intake includes everything needed for installation, installs in under one hour, and works perfectly with the stock tune. The mandrel-bent aluminium intake pipe is available with a red or black powder-coated finish or a polished aluminium finish. This pipe utilizes the Mishimoto air straightener and CNC-machined mass airflow sensor (MAF) housing to provide accurate and consistent MAF readings, which translates into a smooth power band. To reduce air intake temperatures (IATs), the air filter has been placed outside the hot engine bay, and a powder-coated heat shield prevents any heat-soak from occurring. The Mishimoto free-flowing air filter provides a 16% greater surface area, optimal airflow, and proper filtration of dirt and debris. The included Mishimoto oiled air filter is completely serviceable, allowing for a lifetime of reliable use. Additionally, this kit includes a silicone coupler, clamps, and all other hardware necessary to complete a quick installation for easy bolt-on power. A rubber cap is provided to place over the sound symposer housing. Along with an upgrade in power, this intake also provides an aggressive and rich intake tone that is a huge improvement over the stock intake. The Mishimoto Subaru WRX/STI Performance Air Intake is designed in Delaware, USA and includes the Mishimoto Lifetime Warranty