This kit gave 18 HP when dyno'd on a 1996 Impala SS 5.7L. The Generation II FIPK is K&N's ultimate performance product, designed to increase power by as much as 10%. Every FIPK is street legal in all 50 US states & comes with a 10 year/1,000,000 mile limited warranty. K&N intake systems replace your vehicle's restrictive factory air filter and air intake housing. K&N intakes are designed to dramatically reduce intake restriction as they smooth and straighten air flow, allowing your vehicle's engine to inhale a larger volume of air. More air means more usable power and acceleration throughout the engine's RPM range. The filters on these kits are washable and reusable.