Windage is the turbulent flow of air within the crankcase caused by rotation of the crankshaft. As rpm increases, so does windage. Chevrolet Performance windage trays reduce aeration of the oil from windage, permit rapid oil return, and protect from oil splash-back—resulting in more horsepower and improved oil control for your performance engine. Select the right windage tray for your specific vehicle and engine application; get more positive engine lubrication, and reclaim lost horsepower!