Fuel Saving Aerodynamic System | Class 8 Tractor AeroKit | Quick-Release Wheel Covers The FlowBelow Tractor AeroKit™ is a tractor mounted aerodynamics system that offers proven fuel savings of 2.23% for van, reefer, tanker and flatbed fleet operations. FlowBelow began the process of improving tractor aerodynamics by first laser scanning a modern class 8 tractor. Our team of mechanical/aerospace engineers and physicists analyzed the airflow using computational fluid dynamics (CFD) with a focus on the most drag-intensive areas and then designed the FlowBelow Tractor AeroKit™ to optimize the turbulent airflow around the tandem area of the tractor.