Abstract
After three and one-half years of preperation, the Dept. of Transportation/Society of Automotive Engineers Fuel Economy Prog. is currently carrying out its objective of testing vehicles in fleet to measure fuel consumption and to identify the most fuel-efficient operating practices for future use in heavy-vehicle and component design. Tractors comparisons features standard components, vs. high torque rise engines, temperature-controlled fan drives, radial tires, and air deflectors.