The purpose of a chassis fairing, sometimes called a chassis or fuel tank skirt, is to provide a clean aerodynamic surface and eliminate the steps, air, fuel and diesel fluid tanks, battery boxes, etc. that increase the drag of an exposed chassis. They also are designed to kick air slightly outboard of the tractor drive wheels, preventing the air from directly impacting the face of the tire tread.
Chassis fairings run from the cab steps to the end of the sleeper or with extensions to the first drive wheel. Sleeper chassis fairings generally are required for SmartWay designated tractors.
Fuel Savings (If Coupled with Higher Capacity and Higher Voltage Electrical System)
Not Available for Most Vehicles as of March 2017
Increased Complexity of Electrical System
Higher Electrical System Voltage and Power Output Required
Increased Maintenance Costs