K&N Performance Air Intake System (57-2575) BMW > 5 Series > 528i > N20 by simply changing the piston

by simply changing the piston preload spring inside the valve

Only needs cleaning every 50

100mm from 13mm diameter up to 57mm

The standard hose can be restrictive and more so with earlier models that contained a noise generator

K&N Performance Air Intake System (57-2575) BMW > 5 Series > 528i > N20 by simply changing the pistonA high density polyethylene (HDPE) rotationally molded tube helps increase the volume of airflow to your engine, and provides a guaranteed increase in horsepower and torque. These systems are paired with a washable, reusable High Flow Air Filter featuring oiled cotton filter media. The oversized, conical design allows you to go up to 100,000 miles between filter services under normal highway driving conditions. A custom heat shield helps protect