AMSOIL Performance Improver- PI, will restore and clean fuel injectors up to 100% flow. PI will also restore engine horsepower up to 14%. Taking your vehicle to the dealer to get the injectors cleaned will be expensive. Adding the recommended amount to your gas next fill-up will not only clean your injectors and restore lost horsepower but will also increase your vehicle’s fuel mileage up to 5.7%. AMSOIL recommends adding PI every 5000 miles for clean injectors and top performance from your engine, read more.