The plastic factory airbox is good at muffling intake noise and enhancing low rpm/low speed engine performance, but becomes very restrictive when the engine is operating in the higher rpm range – where most performance drivers need it.The NEUSPEED P-Flo allows you to uncork the intake side of your engine, drawing in a nearly unlimited supply of fresh air. Most applications gain an honest 5-8hp at the wheels in the midrange and higher rpms (depending on the vehicle.) Plus, every P-Flo kit includes a high-performance, oiled multi-layer cotton gauze air filter that is washable and reusable. You also get an aggressive, deep throaty engine roar when you step on the gas pedal.