We test; they don't.
Banks' unique 5 bellows accommodates engine movement, preventing component damage and prolonging service life. Filter/Housing/Ducting/Intake Pieces/Clamps/Hardware;California Residents: WARNING Banks Power Banks Ram-Air Intake System - 42230-D Improves power and MPG while lowering exhaust gas temperatures. Its large lifetime air filter requires fewer cleanings than competitive filters. With its giant outlet, streamlined components and enclosed cold-air box that keeps hot engine air out of the intake, the Ram-Air flows up to 66% better than stock.