This kit gave 18 HP when dynode 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 and comes with a 10 Year/ Million Mile Limited Warranty. K&N intake systems replace your vehicles 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. This allows your vehicles engine to inhale a larger volume of air. Much more than the OEM air filter assembly. More air means more usable power and acceleration throughout the engines RPM range. The filters on these kits are washable and reusable.